# kb

id: fluidization-20260505-1
file: data/en.wikipedia.org/wiki/Fluidization-1.md
category: reference
title: Fluidization
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Fluidization
date_saved: 2026-05-05T10:47:54.289691+00:00
instance: kb-cron
parent: fluidization-20260505-0
summary:
Fluidized solids can be easily transferred between reactors. The intense mixing within a fluidized bed means that its temperature is uniform. There is excellent heat transfer between a fluidized bed and heat exchangers immersed in the bed. In the 1920s, the Winkler process was developed to gasify coal in a fluidized bed, using oxygen. It was not commercially successful. The first large scale commercial implementation, in the early 1940s, was the fluid catalytic cracking (FCC) process, which converted heavier petroleum cuts into gasoline. Carbon-rich "coke" deposits on the catalyst particles and deactivates the catalyst in less than 1 second. The fluidized catalyst particles are shuttled between the fluidized bed reactor and a fluidized bed burner where the coke deposits are burned off, generating heat for the endothermic cracking reaction. By the 1950s, fluidized bed technology was being applied to mineral and metallurgical processes such as drying, calcining, and sulfide roasting. In the 1960s, several fluidized bed processes dramatically reduced the cost of some important monomers. Examples are the Sohio process for acrylonitrile and the oxychlorination process for vinyl chloride. These chemical reactions are highly exothermic and fluidization ensures a uniform temperature, minimizing unwanted side reactions, and efficient heat transfer to


id: fluidized-bed-combustion-20260505-0
file: data/en.wikipedia.org/wiki/Fluidized_bed_combustion-0.md
category: reference
title: Fluidized bed combustion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Fluidized_bed_combustion
date_saved: 2026-05-05T10:47:55.510744+00:00
instance: kb-cron
parent: fluidized-bed-combustion-20260505-0
summary:
Fluidized bed combustion (FBC) is a combustion technology used to burn solid fuels. In its most basic form, fuel particles are suspended in a hot, bubbling fluidity bed of ash and other particulate materials (sand, limestone etc.) through which jets of air are blown to provide the oxygen required for combustion or gasification. The resultant fast and intimate mixing of gas and solids promotes rapid heat transfer and chemical reactions within the bed. FBC plants are capable of burning a variety of low-grade solid fuels, including most types of coal, coal waste and woody biomass, at high efficiency and without the necessity for expensive fuel preparation (e.g., pulverising). In addition, for any given thermal duty, FBCs are smaller than the equivalent conventional furnace, so may offer significant advantages over the latter in terms of cost and flexibility. FBC reduces the amount of sulfur emitted in the form of SOx emissions. Limestone is used to precipitate out sulfate during combustion, which also allows more efficient heat transfer from the boiler to the apparatus used to capture the heat energy (usually water tubes). The heated precipitate coming in direct contact with the tubes (heating by conduction) increases the efficiency. This allows coal


id: fluoroether-e-1-20260505-0
file: data/en.wikipedia.org/wiki/Fluoroether_E-1-0.md
category: reference
title: Fluoroether E-1
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Fluoroether_E-1
date_saved: 2026-05-05T10:47:56.739256+00:00
instance: kb-cron
parent: fluoroether-e-1-20260505-0
summary:
Fluoroether E-1 (known chemically as heptafluoropropyl 1,2,2,2-tetrafluoroethyl ether, is a chemical compound that is among the class of per- and polyfluoroalkyl substances (PFAS). This synthetic fluorochemical is used in the GenX process, and may arise from the degradation of GenX chemicals including FRD-903. == Production == The main production of Fluoroether E-1 is within the GenX process where FRD-903 (2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoic acid) is used to generate (FRD-902) ammonium 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propanoate, and Fluoroether E-1 (heptafluoropropyl 1,2,2,2-tetrafluoroethyl ether). == Properties == Fluoroether E-1 is a colorless liquid that is practically insoluble in water. It is volatile and has a low boiling point. == References ==


id: 6-2-fluorotelomersulfonic-acid-20260505-0
file: data/en.wikipedia.org/wiki/6:2-Fluorotelomersulfonic_acid-0.md
category: reference
title: 6:2-Fluorotelomersulfonic acid
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/6:2-Fluorotelomersulfonic_acid
date_saved: 2026-05-05T10:47:57.862696+00:00
instance: kb-cron
parent: 6-2-fluorotelomersulfonic-acid-20260505-0
summary:
6:2-fluorotelomersulfonic acid (6:2-FTS) is a chemical compound that belongs to the group of fluorotelomersulfonic acids within the broader class of per- and polyfluorinated alkyl compounds (PFAS). Due to its structural similarity to perfluorooctanesulfonic acid (PFOS), it is also called H4PFOS. == Production == 6:2-Fluorotelomersulfonic acid is produced via telomerization. In addition, it is also formed, for example, from some perfluorocarboxybetaines after their splitting. == Usage == 6:2-Fluorotelomersulfonic acid and its derivatives are used as a replacement product for perfluorooctanesulfonic acid (PFOS) or its salts in fire-fighting foams. 6:2-FTS has also been used in the chromium plating industry to reduce mist formation during plating. == References ==


id: foam-separation-20260505-0
file: data/en.wikipedia.org/wiki/Foam_separation-0.md
category: reference
title: Foam separation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Foam_separation
date_saved: 2026-05-05T10:47:59.013110+00:00
instance: kb-cron
parent: foam-separation-20260505-0
summary:
Foam separation is a chemical process which falls into a category of separation techniques called "Adsorptive bubble separation methods". It is further divided into froth flotation and foam fractionation. Foam separation is essential in order to prevent contamination of fermentation medium through the foam by external microbes. == References ==


id: formox-process-20260505-0
file: data/en.wikipedia.org/wiki/Formox_process-0.md
category: reference
title: Formox process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Formox_process
date_saved: 2026-05-05T10:48:00.187149+00:00
instance: kb-cron
parent: formox-process-20260505-0
summary:
The Formox process produces formaldehyde. Formox is a registered trademark owned by Johnson Matthey. The process was originally invented jointly by Swedish chemical company Perstorp and Reichhold Chemicals. Industrially, formaldehyde is produced by catalytic oxidation of methanol. The most commonly used catalysts are silver metal or a mixture of an iron oxide with molybdenum and/or vanadium. In the recently more commonly used Formox process using iron oxide and molybdenum and/or vanadium, methanol and oxygen react at 300-400°C to produce formaldehyde according to the chemical equation: CH3OH + ½ O2 → H2CO + H2O. The silver-based catalyst (see also: the Fasil process) is usually operated at a higher temperature, about 650 °C. On it, two chemical reactions simultaneously produce formaldehyde: the one shown above, and the dehydrogenation reaction: CH3OH → H2CO + H2 Further oxidation of the formaldehyde product during its production usually gives formic acid that is found in formaldehyde solution, found in parts per million values. == References ==


id: fowler-process-20260505-0
file: data/en.wikipedia.org/wiki/Fowler_process-0.md
category: reference
title: Fowler process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Fowler_process
date_saved: 2026-05-05T10:48:01.371535+00:00
instance: kb-cron
parent: fowler-process-20260505-0
summary:
The Fowler process is an industry and laboratory route to fluorocarbons, by fluorinating hydrocarbons or their partially fluorinated derivatives in the vapor phase over cobalt(III) fluoride. == Background == The Manhattan Project required the production and handling of uranium hexafluoride for uranium enrichment, whether by diffusion or centrifuge. Uranium hexafluoride is very corrosive, oxidising, volatile solid (sublimes at 56 °C). To handle this material, several new materials were required, including a coolant liquid that could survive contact with uranium hexafluoride. Perfluorocarbons were identified as ideal materials, but at that point no method was available to produce them in any significant quantity. The problem is that fluorine gas is extremely reactive. Simply exposing a hydrocarbon to fluorine will cause the hydrocarbon to ignite. A way to moderate the reaction was required, and the method developed was to react the hydrocarbon with cobalt(III) fluoride, rather than fluorine itself. After World War II, much of the technology that had been kept secret was released into the public domain. The March 1947 issue of Industrial and Engineering Chemistry presented a collection of articles about fluorine chemistry, starting with the generation and handling of fluorine, and going on to discuss the synthesis of organofluorides and


id: frank-caro-process-20260505-0
file: data/en.wikipedia.org/wiki/Frank–Caro_process-0.md
category: reference
title: Frank–Caro process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Frank–Caro_process
date_saved: 2026-05-05T10:48:02.549271+00:00
instance: kb-cron
parent: frank-caro-process-20260505-0
summary:
The Frank–Caro process, also called cyanamide process, is the nitrogen fixation reaction of calcium carbide with nitrogen gas in a reactor vessel at about 1,000 °C. The reaction is exothermic and self-sustaining once the reaction temperature is reached. Originally the reaction took place in large steel cylinders with an electrical resistance element providing initial heat to start the reaction. Modern production uses rotating ovens. The synthesis produces a solid mixture of calcium cyanamide (CaCN2), also known as nitrolime, and carbon. CaC2 + N2 → CaCN2 + C == History == The Frank–Caro process was the first commercial process that was used worldwide to fix atmospheric nitrogen. The product was used as fertilizer and commercially known as Lime-Nitrogen. Nitrolim or Kalkstickstoff in German. The method was developed by the German chemists Adolph Frank and Nikodem Caro between 1895 and 1899. In its first decades, the world market for inorganic fertilizer was dominated by factories utilizing the cyanamide process. === Production facilities === The first full-scale factories were established in 1905 in Piano d´Orta (Italy) and Westeregeln (Germany). From 1908 the Frank–Caro process was used at North Western Cyanamide Company at Odda, Norway. With an annual production capacity of 12,000 ton from


id: galvanization-20260505-0
file: data/en.wikipedia.org/wiki/Galvanization-0.md
category: reference
title: Galvanization
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Galvanization
date_saved: 2026-05-05T10:48:03.729256+00:00
instance: kb-cron
parent: galvanization-20260505-0
summary:
Galvanization (also spelled galvanisation) is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which the parts are coated by submerging them in a bath of hot, molten zinc. Galvanized steel is widely used in applications where corrosion resistance is needed without the cost of stainless steel, and is considered superior in terms of cost and life-cycle. It can be identified by the crystallization patterning on the surface (often called a "spangle"). Galvanized steel can be welded; however, welding gives off toxic zinc fumes. Galvanized fumes are released when the galvanized metal reaches a certain temperature. This temperature varies by the galvanization process used. In long-term, continuous exposure, the recommended maximum temperature for hot-dip galvanized steel is 200 °C (392 °F), according to the American Galvanizers Association. The use of galvanized steel at temperatures above this will result in peeling of the zinc at the inter-metallic layer. Like other corrosion protection systems, galvanizing protects steel by acting as a barrier between steel and the atmosphere. However, zinc is a more electropositive (active) metal in comparison to steel. This is a unique characteristic for galvanizing, which means


id: chemical-garden-20260505-0
file: data/en.wikipedia.org/wiki/Chemical_garden-0.md
category: reference
title: Chemical garden
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Chemical_garden
date_saved: 2026-05-05T10:48:04.929522+00:00
instance: kb-cron
parent: chemical-garden-20260505-0
summary:
A chemical garden is a set of complex biological-looking structures created by mixing inorganic chemicals. This experiment in chemistry is usually performed by adding metal salts, such as copper sulfate or cobalt(II) chloride, to an aqueous solution of sodium silicate (otherwise known as waterglass). This results in the growth of plant-like forms in minutes to hours. The chemical garden was first observed and described by Johann Rudolf Glauber in 1646. In its original form, the chemical garden involved the introduction of ferrous chloride (FeCl2) crystals into a solution of potassium silicate (K2SiO3). == Process == The chemical garden relies on most transition metal silicates being insoluble in water and colored. When a metal salt, such as cobalt chloride, is added to a sodium silicate solution, it will start to dissolve. It will then form insoluble cobalt silicate by a double displacement reaction. This cobalt silicate is a semipermeable membrane. Because the ionic strength of the cobalt solution inside the membrane is higher than the sodium silicate solution's, which forms the bulk of the tank contents, osmotic effects will increase the pressure within the membrane. This will cause the membrane to tear, forming a hole. The cobalt cations will react with


id: glycol-dehydration-20260505-0
file: data/en.wikipedia.org/wiki/Glycol_dehydration-0.md
category: reference
title: Glycol dehydration
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Glycol_dehydration
date_saved: 2026-05-05T10:48:06.124014+00:00
instance: kb-cron
parent: glycol-dehydration-20260505-0
summary:
Glycol dehydration is a liquid desiccant system for the removal of water from natural gas and natural gas liquids (NGL). It is the most common and economical means of water removal from these streams. Glycols typically seen in industry include triethylene glycol (TEG), diethylene glycol (DEG), ethylene glycol (MEG), and tetraethylene glycol (TREG). TEG is the most commonly used glycol in industry. == Purpose == The purpose of a glycol dehydration unit is to remove water from natural gas and natural gas liquids. When produced from a reservoir, natural gas usually contains a large amount of water and is typically completely saturated or at the water dew point. This water can cause several problems for downstream processes and equipment. At low temperatures the water can either freeze in piping or, as is more commonly the case, form hydrates with CO2 and hydrocarbons (mainly methane hydrates). Depending on composition, these hydrates can form at relatively high temperatures plugging equipment and piping. Glycol dehydration units depress the hydrate formation point of the gas through water removal. Without dehydration, a free water phase (liquid water) could also drop out of the natural gas as it is either cooled or the pressure is lowered


id: haber-process-20260505-0
file: data/en.wikipedia.org/wiki/Haber_process-0.md
category: reference
title: Haber process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Haber_process
date_saved: 2026-05-05T10:48:07.304456+00:00
instance: kb-cron
parent: haber-process-20260505-0
summary:
The Haber process, also called the Haber–Bosch process, is the main industrial procedure for the production of ammonia. It converts atmospheric nitrogen (N2) to ammonia (NH3) by a reaction with hydrogen (H2) using finely divided iron metal as a catalyst: N 2 + 3 H 2 ↽ − − ⇀ 2 NH 3 Δ H 298 K ∘ = − 92.28 kJ per mole of N 2 {\displaystyle {\ce {N2 + 3H2 <=> 2NH3}}\qquad {\Delta H_{\mathrm {298~K} }^{\circ }=-92.28~{\text{kJ per mole of }}{\ce {N2}}}} This reaction is exothermic but disfavored in terms of entropy because four equivalents of reactant gases are converted into two equivalents of product gas. However, due to the extremely high kinetic barriers to bond cleavage, high pressures and temperatures are needed to drive the reaction forward. The German chemists Fritz Haber and Carl Bosch developed the process in the first decade of the 20th century, and its improved efficiency over existing methods such as the Birkeland–Eyde and Frank–Caro processes was a major advancement in the industrial production of ammonia. The Haber process can be combined with steam reforming to produce ammonia with just three chemical inputs: water, natural gas, and atmospheric nitrogen. Both Haber and Bosch


id: haber-process-20260505-1
file: data/en.wikipedia.org/wiki/Haber_process-1.md
category: reference
title: Haber process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Haber_process
date_saved: 2026-05-05T10:48:07.304456+00:00
instance: kb-cron
parent: haber-process-20260505-0
summary:
Combined with the energy needed to produce hydrogen and purified atmospheric nitrogen, ammonia production is energy-intensive, accounting for 1–2% of global energy consumption, 3% of global carbon emissions, and 3% to 5% of natural gas consumption. Hydrogen required for ammonia synthesis is most often produced through gasification of hydrocarbons, mostly natural gas, but other potential hydrogen sources include coal, petroleum, peat, biomass, or waste. As of 2012, the global production of ammonia produced from natural gas using the steam reforming process was 72%; however, in China as of 2022, natural gas and coal were responsible for 20% and 75% respectively. Hydrogen can also be produced from water and electricity using electrolysis: at one time, most of Europe's ammonia was produced from the Hydro plant at Vemork. Other possibilities include biological hydrogen production or photolysis, but at present, steam reforming of natural gas is the most economical means of mass-producing hydrogen. The choice of catalyst is important for synthesizing ammonia. In 2012, Hideo Hosono's group reported ammonia synthesis using Ru-loaded calcium-aluminium oxide C12A7:e− electride, describing the electride as an electron donor and reversible hydrogen store. Subsequent work studied nitrogen dissociation and catalytic mechanisms on Ru-loaded C12A7:e−. This method is implemented in


id: haber-process-20260505-2
file: data/en.wikipedia.org/wiki/Haber_process-2.md
category: reference
title: Haber process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Haber_process
date_saved: 2026-05-05T10:48:07.304456+00:00
instance: kb-cron
parent: haber-process-20260505-0
summary:
where ϕ ^ i {\displaystyle {\hat {\phi }}_{i}} is the fugacity coefficient of species i {\displaystyle i} , y i {\displaystyle y_{i}} is the mole fraction of the same species, P {\displaystyle P} is the reactor pressure, and P ∘ {\displaystyle P^{\circ }} is standard pressure, typically 1 bar (0.10 MPa). Economically, reactor pressurization is expensive: pipes, valves, and reaction vessels need to be strong enough, and safety considerations affect operating at 20 MPa. Compressors take considerable energy, as work must be done on the (compressible) gas. Thus, the compromise used gives a single-pass yield of around 15%. While removing the ammonia from the system increases the reaction yield, this step is not used in practice, since the temperature is too high; instead it is removed from the gases leaving the reaction vessel. The hot gases are cooled under high pressure, allowing the ammonia to condense and be removed as a liquid. Unreacted hydrogen and nitrogen gases are returned to the reaction vessel for another round. While most ammonia is removed (typically down to 2–5 mol.%), some ammonia remains in the recycle stream. In academic literature, a more complete separation of ammonia has been proposed by absorption in metal halides,


id: haber-process-20260505-3
file: data/en.wikipedia.org/wiki/Haber_process-3.md
category: reference
title: Haber process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Haber_process
date_saved: 2026-05-05T10:48:07.304456+00:00
instance: kb-cron
parent: haber-process-20260505-0
summary:
=== Catalysts other than iron === Many efforts have been made to improve the Haber–Bosch process. Many metals were tested as catalysts. The requirement for suitability is the dissociative adsorption of nitrogen (i. e. the nitrogen molecule must be split into nitrogen atoms upon adsorption). If the binding of the nitrogen is too strong, the catalyst is blocked and the catalytic ability is reduced (self-poisoning). The elements in the periodic table to the left of the iron group show such strong bonds. Further, the formation of surface nitrides makes, for example, chromium catalysts ineffective. Metals to the right of the iron group, in contrast, adsorb nitrogen too weakly for ammonia synthesis. Haber initially used catalysts based on osmium and uranium. Uranium reacts to its nitride during catalysis, while osmium oxide is rare. According to theoretical and practical studies, improvements over pure iron are limited. The activity of iron catalysts is increased by the inclusion of cobalt. ==== Ruthenium ==== Ruthenium forms highly active catalysts. Allowing milder operating pressures and temperatures, Ru-based materials are referred to as second-generation catalysts. Such catalysts are prepared by the decomposition of triruthenium dodecacarbonyl on graphite. A drawback of activated-carbon-supported ruthenium-based catalysts is the methanation of


id: haber-process-20260505-4
file: data/en.wikipedia.org/wiki/Haber_process-4.md
category: reference
title: Haber process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Haber_process
date_saved: 2026-05-05T10:48:07.304456+00:00
instance: kb-cron
parent: haber-process-20260505-0
summary:
The methane gas reacts in the primary reformer only partially. To increase the hydrogen yield and keep the content of inert components (i. e. methane) as low as possible, the remaining methane gas is converted in a second step with oxygen to hydrogen and carbon monoxide in the secondary reformer. The secondary reformer is supplied with air as the oxygen source. Also, the required nitrogen for the subsequent ammonia synthesis is added to the gas mixture. 2 CH 4 ( g ) + O 2 ( g ) ⟶ 2 CO ( g ) + 4 H 2 ( g ) Δ H ∘ = − 71 kJ / mol {\displaystyle {\ce {{2CH4_{(g)}}+O2_{(g)}->{2CO_{(g)}}+4H2_{(g)}}}\qquad {\Delta H^{\circ }=-71\ {\ce {kJ/mol}}}} In the third step, the carbon monoxide is oxidized to carbon dioxide, which is called CO conversion or water–gas shift reaction. CO ( g ) + H 2 O ( g ) ⟶ CO 2 ( g ) + H 2 ( g ) Δ H ∘ = − 41 kJ / mol {\displaystyle {\ce {{CO_{(g)}}+H2O(g)->{CO2_{(g)}}+H2_{(g)}}}\qquad {\Delta H^{\circ }=-41\ {\ce {kJ/mol}}}} Carbon monoxide and carbon dioxide would form carbamates with ammonia, which would clog (as solids) pipelines and apparatus within a short


id: haber-process-20260505-5
file: data/en.wikipedia.org/wiki/Haber_process-5.md
category: reference
title: Haber process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Haber_process
date_saved: 2026-05-05T10:48:07.304456+00:00
instance: kb-cron
parent: haber-process-20260505-0
summary:
N2 → S*–N2 (γ-species) → S*–N2–S* (α-species) → 2 S*–N (β-species, surface nitride) The adsorption of nitrogen is similar to the chemisorption of carbon monoxide. On a Fe(111) surface, the adsorption of nitrogen first leads to an adsorbed γ-species with an adsorption energy of 24 kJmol−1 and an N-N stretch vibration of 2100 cm−1. Since the nitrogen is isoelectronic to carbon monoxide, it adsorbs in an on-end configuration in which the molecule is bound perpendicular to the metal surface at one nitrogen atom. This has been confirmed by photoelectron spectroscopy. Ab-initio-MO calculations have shown that, in addition to the σ binding of the free electron pair of nitrogen to the metal, there is a π binding from the d orbitals of the metal to the π* orbitals of nitrogen, which strengthens the iron-nitrogen bond. The nitrogen in the α state is more strongly bound with 31 kJmol−1. The resulting N–N bond weakening could be experimentally confirmed by a reduction of the wave numbers of the N–N stretching oscillation to 1490 cm−1. Further heating of the Fe(111) area covered by α-N2 leads to both desorption and the emergence of a new band at 450 cm−1. This represents a metal-nitrogen oscillation, the


id: hall-h-roult-process-20260505-0
file: data/en.wikipedia.org/wiki/Hall–Héroult_process-0.md
category: reference
title: Hall–Héroult process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hall–Héroult_process
date_saved: 2026-05-05T10:48:24.583650+00:00
instance: kb-cron
parent: hall-h-roult-process-20260505-0
summary:
The Hall–Héroult process is the major industrial process for smelting aluminium. It involves dissolving aluminium oxide (alumina) (obtained most often from bauxite, aluminium's chief ore, through the Bayer process) in molten cryolite and electrolyzing the molten salt bath, typically in a purpose-built cell. The process, conducted at an industrial scale, happens at 940–980 °C (1700–1800 °F) and produces aluminium with a purity of 99.5–99.8%. Recycling aluminum, which does not require electrolysis, is thus not treated using this method. The Hall–Héroult process consumes substantial electrical energy, and its electrolysis stage can produce significant amounts of carbon dioxide if the electricity is generated from high-emission sources. Furthermore, the process generates fluorocarbon compounds as byproducts, contributing to both air pollution and climate change. == Process == === Difficulties faced === Elemental aluminium cannot be produced by the electrolysis of an aqueous aluminium salt, because hydronium ions readily oxidize elemental aluminium. Although a molten aluminium salt could be used instead, aluminium oxide has a melting point of 2072 °C (3762 °F) so electrolysing it is impractical. In the Hall–Héroult process, alumina, Al2O3, is dissolved in molten synthetic cryolite, Na3AlF6, to lower its melting point for easier electrolysis. The carbon source is generally a coke


id: hall-h-roult-process-20260505-1
file: data/en.wikipedia.org/wiki/Hall–Héroult_process-1.md
category: reference
title: Hall–Héroult process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hall–Héroult_process
date_saved: 2026-05-05T10:48:24.583650+00:00
instance: kb-cron
parent: hall-h-roult-process-20260505-0
summary:
=== Electrodes === Electrodes in cells are mostly coke which has been purified at high temperatures. Pitch resin or tar is used as a binder. The materials most often used in anodes, coke and pitch resin, are mainly residues from the petroleum industry and need to be of high enough purity so no impurities end up into the molten aluminum or the electrolyte. There are two primary anode technologies using the Hall–Héroult process: Söderberg technology and prebaked technology. In cells using Söderberg or self-baking anodes, there is a single anode per electrolysis cell. The anode is contained within a frame and, as the bottom of the anode turns mainly into CO2 during the electrolysis, the anode loses mass and, being amorphous, it slowly sinks within its frame. More material to the top of the anode is continuously added in the form of briquettes made from coke and pitch. The lost heat from the smelting operation is used to bake the briquettes into the carbon form required for the reaction with alumina. The baking process in Söderberg anodes during electrolysis releases more carcinogenic PAHs and other pollutants than electrolysis with prebaked anodes and, partially for this reason, prebaked anode-using cells have


id: hall-h-roult-process-20260505-2
file: data/en.wikipedia.org/wiki/Hall–Héroult_process-2.md
category: reference
title: Hall–Héroult process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hall–Héroult_process
date_saved: 2026-05-05T10:48:24.583650+00:00
instance: kb-cron
parent: hall-h-roult-process-20260505-0
summary:
=== Economic impact === Aluminium produced via the Hall–Héroult process, in combination with cheaper electric power, helped make aluminium (and incidentally magnesium) an inexpensive commodity rather than a precious metal. This, in turn, helped make it possible for pioneers like Hugo Junkers to utilize aluminium and aluminium-magnesium alloys to make items like metal airplanes by the thousands, or Howard Lund to make aluminium fishing boats. In 2012 it was estimated that 12.7 tons of CO2 emissions are generated per ton of aluminium produced. In the 20th and 21st century the aluminum industry due to its large-scale requirements for cheap electricity has often been sited in locations where such electricity is available. For example Iceland, a country with no notable bauxite reserves and a population of less than half a million, is the world's twelfth largest aluminum producer due to the availability of cheap and plentiful electricity, particularly hydropower. Similarly Aluminerie Alouette in Sept-Îles, Quebec, is dependent for its electricity needs on the 5,428 MW Churchill Falls Generating Station operated by Churchill Falls (Labrador) Corporation Limited. The company town of Kitimat in British Columbia was built by Alcan to meet the growing demand for aluminum in the postwar era. It makes


id: haworth-synthesis-20260505-0
file: data/en.wikipedia.org/wiki/Haworth_synthesis-0.md
category: reference
title: Haworth synthesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Haworth_synthesis
date_saved: 2026-05-05T10:48:25.748094+00:00
instance: kb-cron
parent: haworth-synthesis-20260505-0
summary:
The Haworth synthesis is a multistep preparation of alkyl-substituted polycyclic aromatic hydrocarbons developed by the British chemist Robert Downs Haworth in 1932. == References ==


id: holt-dern-process-20260505-0
file: data/en.wikipedia.org/wiki/Holt-Dern_process-0.md
category: reference
title: Holt-Dern process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Holt-Dern_process
date_saved: 2026-05-05T10:48:26.909442+00:00
instance: kb-cron
parent: holt-dern-process-20260505-0
summary:
The Holt-Dern process is a method by which silver and gold can be extracted from low-grade ores. The method was applied in mining at Park City, Utah, and in the Tintic Mining District at the Tintic Smelter Site. It was named for George Dern and T.P. Holt. == References ==


id: hydrochloric-acid-regeneration-20260505-0
file: data/en.wikipedia.org/wiki/Hydrochloric_acid_regeneration-0.md
category: reference
title: Hydrochloric acid regeneration
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hydrochloric_acid_regeneration
date_saved: 2026-05-05T10:48:29.162088+00:00
instance: kb-cron
parent: hydrochloric-acid-regeneration-20260505-0
summary:
Hydrochloric acid regeneration or HCl regeneration is a chemical process for the reclamation of bound and unbound HCl from metal chloride solutions such as hydrochloric acid. == Field of application == The commercially most relevant field of application for HCl regeneration processes is the recovery of HCl from waste pickle liquors from carbon-steel pickling lines. Other applications include the production of metal oxides such as, but not limited, to Al2O3 and MgO, as well as rare-earth oxides, by pyrohydrolysis of aqueous metal chloride or rare-earth chloride solutions. A number of different process routes are available. The most widely used is based on pyrohydrolysis and adiabatic absorption of hydrogen chloride in water, a process invented in the 1960s. However tightening environmental standards and stringent air permit policies render it increasingly difficult to establish new pyrohydrolysis-based acid regeneration plants. == Known processes == The following processes for the regeneration of HCl from spent pickle liquors have been adopted by the ferrous metals processing industry: === Regeneration === Pyrohydrolysis Spray roaster pyrohydrolysis Fluidised bed pyrohydrolysis Hydrothermal regeneration Electrolytic Fe precipitation === Recovery of free HCl === Retardation Dialysis Ion exchange === Transformation of FeCl2 to FeCl3 === Electrolytic oxidation Chemical oxidation == Hydrothermal


id: hydrodenitrogenation-20260505-0
file: data/en.wikipedia.org/wiki/Hydrodenitrogenation-0.md
category: reference
title: Hydrodenitrogenation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hydrodenitrogenation
date_saved: 2026-05-05T10:48:30.335190+00:00
instance: kb-cron
parent: hydrodenitrogenation-20260505-0
summary:
Hydrodenitrogenation (HDN) is an industrial process for the removal of nitrogen from petroleum. Organonitrogen compounds, even though they occur at low levels, are undesirable because they cause poisoning of downstream catalysts. Furthermore, upon combustion, organonitrogen compounds generate NOx, a pollutant. HDN is effected as general hydroprocessing, which traditionally focuses on hydrodesulfurization (HDS) because sulfur compounds are even more problematic. To some extent, hydrodeoxygenation (HDO) is also effected. Typical organonitrogen compounds in petroleum include quinolines and porphyrins and their derivatives. The total nitrogen content is typically less than 1% and the targeted levels are in the ppm range. As described in organic geochemistry, organonitrogen compounds are derivatives or degradation products of the compounds in the living matter that comprised the precursor to fossil fuels. In HDN, the organonitrogen compounds are treated at high temperatures with hydrogen in the presence of a catalyst, the net transformation being: R3N + 3 H2 → 3 RH + NH3 The catalysts generally consist of cobalt and nickel as well as molybdenum disulfide or less often tungsten disulfide supported on alumina. The precise composition of the catalyst, i.e. Co/Ni and Mo/W ratios, are tuned for particular feedstocks. A wide variety of catalyst compositions have been considered,


id: hydrodeoxygenation-20260505-0
file: data/en.wikipedia.org/wiki/Hydrodeoxygenation-0.md
category: reference
title: Hydrodeoxygenation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hydrodeoxygenation
date_saved: 2026-05-05T10:48:31.469693+00:00
instance: kb-cron
parent: hydrodeoxygenation-20260505-0
summary:
Hydrodeoxygenation (HDO) is a hydrogenolysis process for removing oxygen from oxygen-containing compounds. Typical HDO catalysts commonly are sulfided nickel-molybdenum or cobalt-molybdenum on gamma alumina. An idealized reaction is: R2O + 2 H2 → H2O + 2 RH The first review on HDO was published in 1983. HDO is of interest in producing biofuels, which are derived from oxygen-rich precursors like sugars or lipids. An example of a biomass refining process employing hydrodeoxygenation is the NEXBTL process. HDO of biomass fast pyrolysis vapors under low hydrogen pressures have recently attracted a lot of attention. Bulk molybdenum trioxide (MoO3) was used as catalyst and found to completely deoxygenate cellulose, corn stover, and lignin pyrolysis vapors and produce a stream of hydrocarbons including aromatics, alkenes, and alkanes. From an economic viewpoint, only aromatics and alkenes should ideally be produced to enable product incorporation into the existing infrastructure. == References ==


id: hydrodesulfurization-20260505-0
file: data/en.wikipedia.org/wiki/Hydrodesulfurization-0.md
category: reference
title: Hydrodesulfurization
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hydrodesulfurization
date_saved: 2026-05-05T10:48:32.694698+00:00
instance: kb-cron
parent: hydrodesulfurization-20260505-0
summary:
Hydrodesulfurization (HDS), also called hydrotreatment or hydrotreating, is a catalytic chemical process widely used to remove sulfur (S) from natural gas and from refined petroleum products, such as gasoline or petrol, jet fuel, kerosene, diesel fuel, and fuel oils. The purpose of removing the sulfur, and creating products such as ultra-low-sulfur diesel, is to reduce the sulfur dioxide (SO2) emissions that result from using those fuels in automotive vehicles, aircraft, railroad locomotives, ships, gas or oil burning power plants, residential and industrial furnaces, and other forms of fuel combustion. Another important reason for removing sulfur from the naphtha streams within a petroleum refinery is that sulfur, even in extremely low concentrations, poisons the noble metal catalysts (platinum and rhenium) in the catalytic reforming units that are subsequently used to upgrade the octane rating of the naphtha streams. The industrial hydrodesulfurization processes include facilities for the capture and removal of the resulting hydrogen sulfide (H2S) gas. In petroleum refineries, the hydrogen sulfide gas is then subsequently converted into byproduct, sulfur (S) or sulfuric acid (H2SO4). In fact, the vast majority of the 64,000,000 metric tons of sulfur produced worldwide in 2005 was byproduct sulfur from refineries and other hydrocarbon processing plants.


id: hydrodesulfurization-20260505-1
file: data/en.wikipedia.org/wiki/Hydrodesulfurization-1.md
category: reference
title: Hydrodesulfurization
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hydrodesulfurization
date_saved: 2026-05-05T10:48:32.694698+00:00
instance: kb-cron
parent: hydrodesulfurization-20260505-0
summary:
The liquid feed (at the bottom left in the diagram) is pumped up to the required elevated pressure and is joined by a stream of hydrogen-rich recycle gas. The resulting liquid-gas mixture is preheated by flowing through a heat exchanger. The preheated feed then flows through a fired heater where the feed mixture is totally vaporized and heated to the required elevated temperature before entering the reactor and flowing through a fixed-bed of catalyst where the hydrodesulfurization reaction takes place. The hot reaction products are partially cooled by flowing through the heat exchanger where the reactor feed was preheated and then flows through a water-cooled heat exchanger before it flows through the pressure controller (PC) and undergoes a pressure reduction down to about 3 to 5 atmospheres. The resulting mixture of liquid and gas enters the gas separator pressure vessel at about 35 °C and 3 to 5 atmospheres of absolute pressure. Most of the hydrogen-rich gas from the gas separator vessel is recycle gas, which is routed through an amine contactor for removal of the reaction product H2S that it contains. The H2S-free hydrogen-rich gas is then recycled back for reuse in the reactor section. Any excess gas from


id: hydrodesulfurization-20260505-2
file: data/en.wikipedia.org/wiki/Hydrodesulfurization-2.md
category: reference
title: Hydrodesulfurization
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hydrodesulfurization
date_saved: 2026-05-05T10:48:32.694698+00:00
instance: kb-cron
parent: hydrodesulfurization-20260505-0
summary:
== Other uses == The basic hydrogenolysis reaction has a number of uses other than hydrodesulfurization. === Hydrodenitrogenation === The hydrogenolysis reaction is also used to reduce the nitrogen content of a petroleum stream in a process referred to as hydrodenitrogenation (HDN). The process flow is the same as that for an HDS unit. Using pyridine (C5H5N), a nitrogen compound present in some petroleum fractionation products, as an example, the hydrodenitrogenation reaction has been postulated as occurring in three steps: C 5 H 5 N Pyridine + 5 H 2 Hydrogen ⟶ C 5 H 11 N Piperdine + 2 H 2 Hydrogen ⟶ C 5 H 11 NH 2 Amylamine + H 2 Hydrogen ⟶ C 5 H 12 Pentane + NH 3 Ammonia {\displaystyle {\ce {{\overset {Pyridine}{C5H5N}}+ {\overset {Hydrogen}{5H2}}-> {\overset {Piperdine}{C5H11N}}+ {\overset {Hydrogen}{2H2}}-> {\overset {Amylamine}{C5H11NH2}}+ {\overset {Hydrogen}{H2}}-> {\overset {Pentane}{C5H12}}+ {\overset {Ammonia}{NH3}}}}} and the overall reaction may be simply expressed as: C 5 H 5 N Pyridine + 5 H 2 Hydrogen ⟶ C 5 H 12 Pentane + NH 3 Ammonia {\displaystyle {\ce {{\overset {Pyridine}{C5H5N}}+ {\overset {Hydrogen}{5H2}}-> {\overset {Pentane}{C5H12}}+ {\overset {Ammonia}{NH3}}}}} Many HDS units for desulfurizing naphthas within petroleum refineries are actually simultaneously denitrogenating to some extent as


id: hydrodimerization-20260505-0
file: data/en.wikipedia.org/wiki/Hydrodimerization-0.md
category: reference
title: Hydrodimerization
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hydrodimerization
date_saved: 2026-05-05T10:48:33.825740+00:00
instance: kb-cron
parent: hydrodimerization-20260505-0
summary:
Hydrodimerization is an organic reaction that couples two alkenes to give a symmetrical hydrocarbon. The reaction is often implemented electrochemically; in that case the reaction is called electrodimerization. The reaction can also be induced with samarium diiodide, a one-electron reductant. Hydrodimerization is the basis of the Monsanto adiponitrile synthesis: 2 CH2=CHCN + 2 e− + 2 H+ → NCCH2CH2CH2CH2CN The reaction applies to a number electrophilic alkenes (Michael acceptors). == References ==


id: hydrogen-assisted-magnesiothermic-reduction-20260505-0
file: data/en.wikipedia.org/wiki/Hydrogen_assisted_magnesiothermic_reduction-0.md
category: reference
title: Hydrogen assisted magnesiothermic reduction
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hydrogen_assisted_magnesiothermic_reduction
date_saved: 2026-05-05T10:48:35.041974+00:00
instance: kb-cron
parent: hydrogen-assisted-magnesiothermic-reduction-20260505-0
summary:
The hydrogen assisted magnesiothermic reduction ("HAMR") process is a thermochemical process to obtain titanium metal from titanium oxides. A technical challenge in the production of titanium metal is the formation of oxide impurities. The Kroll process, which is widely used commercially, addresses this challenge by converting titanium ore (an oxide) into titanium tetrachloride (TiCl4). This intermediate is readily purified. It is reduced to titanium metal with magnesium. This technology is both capital, energy, and carbon-intensive. One advantage of the Kroll process, and several like it, is that it starts with titanium ores (e.g., illmenite), not a purified dioxide. The HAMR technology also entails a two step process, starting with TiO2 under an atmosphere of hydrogen gas. The product TiH2 can be further processed to titanium metal through standard methods. The reduction of titanium oxides to titanium metal using magnesium does not occur. The novelty of the HAMR process is the inclusion of hydrogen. == References == "HAMR Process for Titanium Production Powder Research Lab - Department of Metallurgical Engineering - The University of Utah". powder.metallurgy.utah.edu.


id: hydrometallurgy-20260505-0
file: data/en.wikipedia.org/wiki/Hydrometallurgy-0.md
category: reference
title: Hydrometallurgy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hydrometallurgy
date_saved: 2026-05-05T10:48:36.216112+00:00
instance: kb-cron
parent: hydrometallurgy-20260505-0
summary:
Hydrometallurgy is a technique within the field of extractive metallurgy, the obtaining of metals from their ores. Hydrometallurgy uses solutions to recover metals from ores, concentrates, and recycled or residual materials. Usually the extracting solution is aqueous (water-based), often containing additives such as acids. In select cases, the extracting solvent is nonaqueous. Processing techniques that complement hydrometallurgy are pyrometallurgy, vapour metallurgy, and molten salt electrometallurgy. Hydrometallurgy is typically divided into three general areas: Leaching Solution concentration and purification Metal or metal compound recovery == Leaching == Leaching involves the use of aqueous solutions to extract metal from metal-bearing materials. The extracting solution is called a lixiviant. The lixiviant is optimized in terms of pH, oxidation-reduction potential, presence of chelating agents, and temperature. In a simple implementation, a slurry of the pulverized ore in the lixiviant solution is filtered to yield a solution containing the metal ion(s) of interest. For example copper in its carbonate minerals such as malachite dissolve in aqueous sulfuric acid. On the other hand, copper sulfide minerals, which are more prevalent, are not amenable to hydrometallurgy, at least until they have been roasted. Hydrometallurgy is used to extract rare earths. By using chelating agents, one can selectively


id: hydrothermal-liquefaction-20260505-0
file: data/en.wikipedia.org/wiki/Hydrothermal_liquefaction-0.md
category: reference
title: Hydrothermal liquefaction
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hydrothermal_liquefaction
date_saved: 2026-05-05T10:48:37.443697+00:00
instance: kb-cron
parent: hydrothermal-liquefaction-20260505-0
summary:
Hydrothermal liquefaction (HTL) is a thermal depolymerization process used to convert wet biomass, and other macromolecules, into crude-like oil under moderate temperature and high pressure. The crude-like oil has high energy density with a lower heating value of 33.8-36.9 MJ/kg and 5-20 wt% oxygen and renewable chemicals. The process has also been called hydrous pyrolysis. The reaction usually involves homogeneous and/or heterogeneous catalysts to improve the quality of products and yields. Carbon and hydrogen of an organic material, such as biomass, peat or low-ranked coals (lignite) are thermo-chemically converted into hydrophobic compounds with low viscosity and high solubility. Depending on the processing conditions, the fuel can be used as produced for heavy engines, including marine and rail or upgraded to transportation fuels, such as diesel, gasoline or jet-fuels. The process may be significant in the creation of fossil fuels. Simple heating without water, anhydrous pyrolysis has long been considered to take place naturally during the catagenesis of kerogens to fossil fuels. In recent decades it has been found that water under pressure causes more efficient breakdown of kerogens at lower temperatures than without it. The carbon isotope ratio of natural gas also suggests that hydrogen from water has been added


id: hydrothermal-liquefaction-20260505-1
file: data/en.wikipedia.org/wiki/Hydrothermal_liquefaction-1.md
category: reference
title: Hydrothermal liquefaction
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hydrothermal_liquefaction
date_saved: 2026-05-05T10:48:37.443697+00:00
instance: kb-cron
parent: hydrothermal-liquefaction-20260505-0
summary:
=== Feedstock === Theoretically, any biomass can be converted into bio-oil using hydrothermal liquefaction regardless of water content, and various different biomasses have been tested, from forestry and agriculture residues, sewage sludges, food process wastes, to emerging non-food biomass such as algae. The composition of cellulose, hemicellulose, protein, and lignin in the feedstock influence the yield and quality of the oil from the process. Zhang et al., at the University of Illinois, report on a hydrous pyrolysis process in which swine manure is converted to oil by heating the swine manure and water in the presence of carbon monoxide in a closed container. For that process they report that a temperatures of at least 275 °C (527 °F) is required to convert the swine manure to oil, and temperatures above about 335 °C (635 °F) reduces the amount of oil produced. The Zhang et al. process produces pressures of about 7 to 18 Mpa (1000 to 2600 psi - 69 to 178 atm), with higher temperatures producing higher pressures. Zhang et al. used a retention time of 120 minutes for the reported study, but report at higher temperatures a time of less than 30 minutes results in significant production of


id: hydrothermal-liquefaction-20260505-2
file: data/en.wikipedia.org/wiki/Hydrothermal_liquefaction-2.md
category: reference
title: Hydrothermal liquefaction
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hydrothermal_liquefaction
date_saved: 2026-05-05T10:48:37.443697+00:00
instance: kb-cron
parent: hydrothermal-liquefaction-20260505-0
summary:
== Comparison with pyrolysis and other biomass to liquid technologies == The HTL process differs from pyrolysis as it can process wet biomass and produce a bio-oil that contains approximately twice the energy density of pyrolysis oil. Pyrolysis is a related process to HTL, but biomass must be processed and dried in order to increase the yield. The presence of water in pyrolysis drastically increases the heat of vaporization of the organic material, increasing the energy required to decompose the biomass. Typical pyrolysis processes require a water content of less than 40% to suitably convert the biomass to bio-oil. This requires considerable pretreatment of wet biomass such as tropical grasses, which contain a water content as high as 80-85%, and even further treatment for aquatic species, which can contain higher than 90% water content. The HTL oil can contain up to 80% of the feedstock carbon content (single pass). HTL oil has good potential to yield bio-oil with "drop-in" properties that can be directly distributed in existing petroleum infrastructure. The energy returned on energy invested (EROEI) of these processes is uncertain and/or has not been measured. Furthermore, products of hydrous pyrolysis might not meet current fuel standards. Further processing may


id: integrated-gasification-combined-cycle-20260505-0
file: data/en.wikipedia.org/wiki/Integrated_gasification_combined_cycle-0.md
category: reference
title: Integrated gasification combined cycle
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Integrated_gasification_combined_cycle
date_saved: 2026-05-05T10:48:38.638828+00:00
instance: kb-cron
parent: integrated-gasification-combined-cycle-20260505-0
summary:
An integrated gasification combined cycle (IGCC) is a technology using a high pressure gasifier to turn coal and other carbon based fuels into pressurized synthesis gas. This enables removal of impurities from the fuel prior to generating electricity, reducing emissions of sulfur dioxide, particulates, mercury, and in some cases carbon dioxide. Some of these impurities, such as sulfur, can be turned into re-usable byproducts through the Claus process. With additional process equipment, carbon monoxide can be converted to carbon dioxide via water-gas shift reaction, enabling it to be sequestered and increasing gasification efficiency. Excess heat from the primary combustion and syngas fired generation is then passed to a steam cycle, producing additional electricity. This process results in improved thermodynamic efficiency, compared to conventional pulverized coal combustion. == Significance == Coal can be found in abundance in the USA and many other countries and its price has remained relatively constant in recent years. Of the traditional hydrocarbon fuels - oil, coal, and natural gas - coal is used as a feedstock for 40% of global electricity generation. Fossil fuel consumption and its contribution to large-scale CO2 emissions is becoming a pressing issue because of the adverse effects of climate change. In


id: integrated-gasification-combined-cycle-20260505-1
file: data/en.wikipedia.org/wiki/Integrated_gasification_combined_cycle-1.md
category: reference
title: Integrated gasification combined cycle
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Integrated_gasification_combined_cycle
date_saved: 2026-05-05T10:48:38.638828+00:00
instance: kb-cron
parent: integrated-gasification-combined-cycle-20260505-0
summary:
== Installations == The DOE Clean Coal Demonstration Project helped construct 3 IGCC plants: Edwarsport Power Station in Edwardsport, Indiana, Polk Power Station in Tampa, Florida (online 1996), and Pinon Pine in Reno, Nevada. In the Reno demonstration project, researchers found that then-current IGCC technology would not work more than 300 feet (100m) above sea level. The DOE report in reference 3 however makes no mention of any altitude effect, and most of the problems were associated with the solid waste extraction system. The Polk Power station is currently operating, following resolution of demonstration start-up problems, but the Piñon Pine project encountered significant problems and was abandoned. The US DOE's Clean Coal Power Initiative (CCPI Phase 2) selected the Kemper Project as one of two projects to demonstrate the feasibility of low emission coal-fired power plants. Mississippi Power began construction on the Kemper Project in Kemper County, Mississippi, in 2010 and is poised to begin operation in 2016, though there have been many delays. In March, the projected date was further pushed back from early 2016 to August 31, 2016, adding $110 million to the total and putting the project 3 years behind schedule. The electrical plant is a flagship


id: integrated-gasification-combined-cycle-20260505-2
file: data/en.wikipedia.org/wiki/Integrated_gasification_combined_cycle-2.md
category: reference
title: Integrated gasification combined cycle
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Integrated_gasification_combined_cycle
date_saved: 2026-05-05T10:48:38.638828+00:00
instance: kb-cron
parent: integrated-gasification-combined-cycle-20260505-0
summary:
== Cost and reliability == A key issue in implementing IGCC is its high capital cost, which prevents it from competing with other power plant technologies. Currently, ordinary pulverized coal plants are the lowest cost power plant option. The advantage of IGCC comes from the ease of retrofitting existing power plants that could offset the high capital cost. In a 2007 model, IGCC with CCS is the lowest-cost system in all cases. This model compared estimations of levelized cost of electricity, showing IGCC with CCS to cost 71.9 $US2005/MWh, pulverized coal with CCS to cost 88 $US2005/MWh, and natural gas combined cycle with CCS to cost 80.6 $US2005/MWh. The levelized cost of electricity was noticeably sensitive to the price of natural gas and the inclusion of carbon storage and transport costs. The potential benefit of retrofitting has so far, not offset the cost of IGCC with carbon capture technology. A 2013 report by the U.S. Energy Information Administration demonstrates that the overnight cost of IGCC with CCS has increased 19% since 2010. Amongst the three power plant types, pulverized coal with CCS has an overnight capital cost of $5,227 (2012 dollars)/kW, IGCC with CCS has an overnight capital cost of


id: integrated-gasification-combined-cycle-20260505-3
file: data/en.wikipedia.org/wiki/Integrated_gasification_combined_cycle-3.md
category: reference
title: Integrated gasification combined cycle
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Integrated_gasification_combined_cycle
date_saved: 2026-05-05T10:48:38.638828+00:00
instance: kb-cron
parent: integrated-gasification-combined-cycle-20260505-0
summary:
None of these facilities use advanced technology (F type) gas turbines. All refinery-based plants use refinery residues, rather than coal, as the feedstock. This eliminates coal handling and coal preparation equipment and its problems. Also, there is a much lower level of ash produced in the gasifier, which reduces cleanup and downtime in its gas cooling and cleaning stages. These non-utility plants have recognized the need to treat the gasification system as an up-front chemical processing plant, and have reorganized their operating staff accordingly. Another IGCC success story has been the 250 MW Buggenum plant in The Netherlands, which was commissioned in 1994 and closed in 2013, had good availability. This coal-based IGCC plant was originally designed to use up to 30% biomass as a supplemental feedstock. The owner, NUON, was paid an incentive fee by the government to use the biomass. NUON has constructed a 1,311 MW IGCC plant in the Netherlands, comprising three 437 MW CCGT units. The Nuon Magnum IGCC power plant was commissioned in 2011, and was officially opened in June 2013. Mitsubishi Heavy Industries has been awarded to construct the power plant. Following a deal with environmental organizations, NUON has been prohibited from using the


id: integrated-gasification-combined-cycle-20260505-4
file: data/en.wikipedia.org/wiki/Integrated_gasification_combined_cycle-4.md
category: reference
title: Integrated gasification combined cycle
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Integrated_gasification_combined_cycle
date_saved: 2026-05-05T10:48:38.638828+00:00
instance: kb-cron
parent: integrated-gasification-combined-cycle-20260505-0
summary:
== Testing == National and international test codes are used to standardize the procedures and definitions used to test IGCC Power Plants. Selection of the test code to be used is an agreement between the purchaser and the manufacturer, and has some significance to the design of the plant and associated systems. In the United States, The American Society of Mechanical Engineers published the Performance Test Code for IGCC Power Generation Plants (PTC 47) in 2006 which provides procedures for the determination of quantity and quality of fuel gas by its flow rate, temperature, pressure, composition, heating value, and its content of contaminants. == IGCC emission controversy == In 2007, the New York State Attorney General's office demanded full disclosure of "financial risks from greenhouse gases" to the shareholders of electric power companies proposing the development of IGCC coal-fired power plants. "Any one of the several new or likely regulatory initiatives for CO2 emissions from power plants - including state carbon controls, EPA's regulations under the Clean Air Act, or the enactment of federal global warming legislation - would add a significant cost to carbon-intensive coal generation"; U.S. Senator Hillary Clinton from New York has proposed that this full risk


id: intramolecular-vibrational-energy-redistribution-20260505-0
file: data/en.wikipedia.org/wiki/Intramolecular_vibrational_energy_redistribution-0.md
category: reference
title: Intramolecular vibrational energy redistribution
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Intramolecular_vibrational_energy_redistribution
date_saved: 2026-05-05T10:48:39.763766+00:00
instance: kb-cron
parent: intramolecular-vibrational-energy-redistribution-20260505-0
summary:
Intramolecular vibrational energy redistribution (IVR) is a process in which energy is redistributed between different quantum states of a vibrationally excited molecule, which is required by successful theories explaining unimolecular reaction rates such as RRKM theory. Such theories assume a full statistical redistribution between all vibrational modes, but restricted redistribution could enable bond selective chemistry for which deposited energy must remain in a particular mode for as long as it takes for the required reaction to take place. == References ==


id: inverse-vulcanization-20260505-0
file: data/en.wikipedia.org/wiki/Inverse_vulcanization-0.md
category: reference
title: Inverse vulcanization
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Inverse_vulcanization
date_saved: 2026-05-05T10:48:40.977282+00:00
instance: kb-cron
parent: inverse-vulcanization-20260505-0
summary:
Inverse vulcanization is a process that produces polysulfide polymers, which also contain some organic linkers. In contrast, sulfur vulcanization produces material that is predominantly organic but has a small percentage of polysulfide crosslinks. == Synthesis == Like Thiokols and sulfur-vulcanization, inverse vulcanization uses the tendency of sulfur catenate. The polymers produced by inverse vulcanization consist of long sulfur linear chains interspersed with organic linkers. Traditional sulfur vulcanization produces a cross-linked material with short sulfur bridges, down to one or two sulfur atoms. The polymerization process begins with the heating of elemental sulfur above its melting point (115.21 °C), to favor the ring-opening polymerization process (ROP) of the S8 monomer, occurring at 159 °C. As a result, the liquid sulfur is constituted by linear polysulfide chains with diradical ends, which can be easily bridged together with small dienes, such as 1,3-Diisopropylbenzene(DIB), 1,4-diphenylbutadiyne, limonene, divinylbenzene (DVB), dicyclopentadiene, styrene, 4-vinylpyridine, cycloalkene and ethylidene norbornene, or longer organic molecules as polybenzoxazines, squalene and triglyceride. Chemically, the diene carbon-carbon double bond (C=C) of the substitutional group disappears, forming the carbon-sulfur single bond (C-S) which binds together the sulfur linear chains. The advantage of such a polymerization is the absence of a solvent; Sulphur acts as


id: ion-beam-mixing-20260505-0
file: data/en.wikipedia.org/wiki/Ion_beam_mixing-0.md
category: reference
title: Ion beam mixing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ion_beam_mixing
date_saved: 2026-05-05T10:48:42.165521+00:00
instance: kb-cron
parent: ion-beam-mixing-20260505-0
summary:
Ion beam mixing is the atomic intermixing and alloying that can occur at the interface separating two different materials during ion irradiation. It is applied as a process for adhering two multilayers, especially a substrate and deposited surface layer. The process involves bombarding layered samples with doses of ion radiation in order to promote mixing at the interface, and generally serves as a means of preparing electrical junctions, especially between non-equilibrium or metastable alloys and intermetallic compounds. Ion implantation equipment can be used to achieve ion beam mixing. == Mechanism == The unique effects that stem from ion beam mixing are primarily a result of ballistic effects; that is, impinging ions have high kinetic energies that are transferred to target atoms on collision. Ion energies can be seen on the order of 1 keV to 200 keV. When accelerated, such ion energies are sufficiently high to break intra- and especially inter-molecular bonds, and initiate relocations within an atomic lattice. The sequence of collisions is known as a collision cascade. During this ballistic process, energies of impinging ions displace atoms and electrons of the target material several lattice sites away, resulting in relocations there and interface mixing at the boundary layer.


id: ion-plating-20260505-0
file: data/en.wikipedia.org/wiki/Ion_plating-0.md
category: reference
title: Ion plating
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Ion_plating
date_saved: 2026-05-05T10:48:43.354201+00:00
instance: kb-cron
parent: ion-plating-20260505-0
summary:
Ion plating (IP) is a physical vapor deposition (PVD) process that is sometimes called ion assisted deposition (IAD) or ion vapor deposition (IVD) and is a modified version of vacuum deposition. Ion plating uses concurrent or periodic bombardment of the substrate, and deposits film by atomic-sized energetic particles called ions. Bombardment prior to deposition is used to sputter clean the substrate surface. During deposition the bombardment is used to modify and control the properties of the depositing film. It is important that the bombardment be continuous between the cleaning and the deposition portions of the process to maintain an atomically clean interface. If this interface is not properly cleaned, then it can result into a weaker coating or poor adhesion. They are many different processes to vacuum deposited coatings in which they are used for various applications such as corrosion resistance and wear on the material. == Process == In ion plating, the energy, flux and mass of the bombarding species along with the ratio of bombarding particles to depositing particles are important processing variables. The depositing material may be vaporized either by evaporation, sputtering (bias sputtering), arc vaporization or by decomposition of a chemical vapor precursor chemical vapor deposition


id: isakidd-refining-technology-20260505-0
file: data/en.wikipedia.org/wiki/IsaKidd_refining_technology-0.md
category: reference
title: IsaKidd refining technology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/IsaKidd_refining_technology
date_saved: 2026-05-05T10:48:44.550207+00:00
instance: kb-cron
parent: isakidd-refining-technology-20260505-0
summary:
The IsaKidd Technology is a copper electrorefining and electrowinning technology that was developed independently by Copper Refineries Proprietary Limited (“CRL”), a Townsville, Queensland, subsidiary of MIM Holdings (which is now part of Glencore, and at the Falconbridge Nickel Mines now-dismantled Kidd Creek refinery that was at Timmins, Ontario. It is based around the use of reusable cathode starter sheets for copper electrorefining and the automated stripping of the deposited “cathode copper” from them. == Overview == === The old way of electrorefining copper (pre-1978) === The usual process of electrorefining copper consists of placing a copper anode (about 99.5–99.7% pure copper) in sulfuric acid (H2SO4) bath of copper electrolyte, together with a cathode, and passing a current between the anode and cathode through an external circuit. At the applied electropotential, copper and less noble elements dissolve in the electrolyte, while elements more noble than copper, such as gold (Au) and silver (Ag), do not. Under the influence of the applied electrical potential, copper ions migrate from the anode and deposit on the cathode, forming cathode copper. The current IsaKidd technology represents the merger of the copper refining technologies developed by the two different organisations. The initial Isa Process development in


id: isakidd-refining-technology-20260505-1
file: data/en.wikipedia.org/wiki/IsaKidd_refining_technology-1.md
category: reference
title: IsaKidd refining technology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/IsaKidd_refining_technology
date_saved: 2026-05-05T10:48:44.550207+00:00
instance: kb-cron
parent: isakidd-refining-technology-20260505-0
summary:
Over time, the formation of starter sheets was improved by mechanisation, but there was still a high labour input. Once the starter sheets were formed, they had to be flattened, to reduce the likelihood of short circuits, and then cut, formed and punched to make loops from which the starter sheets are hung from conductive copper hanger bars in the electrolytic cells (see Figure 1). The starter sheets are inserted in the refining cells and dissolved copper electrodeposits on them to produce the cathode copper product (see Figure 2). Because of the manufacturing cost of the starter sheets, refineries using them tend to keep them in the cells as long as possible, usually 12–14 days. On the other hand, the anodes normally reside in the cells for 24–28 days, meaning that there are two cathodes produced from each anode. The starter sheets have a tendency to warp, due to the mechanical stresses they encounter and often need to be removed from the refining cells after about two days to be straightened in presses before being returned to the cells. The tendency to warp leads to frequent short-circuiting. Due to their limitations, it is difficult for copper produced on starter sheets


id: isakidd-refining-technology-20260505-2
file: data/en.wikipedia.org/wiki/IsaKidd_refining_technology-2.md
category: reference
title: IsaKidd refining technology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/IsaKidd_refining_technology
date_saved: 2026-05-05T10:48:44.550207+00:00
instance: kb-cron
parent: isakidd-refining-technology-20260505-0
summary:
=== Moving into electrowinning plants === The Isa Process was originally developed for the CRL copper electrorefinery in Townsville. It was subsequently licensed to the Copper Range Company for its White Pine copper refinery. The next licence issued was for an electrowinning application at the Broken Hill Associated Smelters (“BHAS”) lead smelter at Port Pirie, in South Australia. BHAS commissioned in 1985 a solvent extraction and electrowinning (“SX–EW”) to recover copper from copper–lead matte produced as a by-product of the lead smelting operations. The process used involves leaching the copper from the material using an acidic chloride–sulfate solution, followed by solvent extraction to concentrate the leached copper and electrowinning. Electrowinning copper differs from electrorefining in that electrorefining uses a copper anode that is dissolved and redeposited on the cathode, while in electrowinning the copper is already in solution and is extracted from the solution by passing a current through the solution using an inert lead-alloy anode, and a cathode. The chloride in the leach solution at Port Pirie proved to be a problem for the stainless steel cathodes of the Isa Process. A small amount of the chloride ions in the leach solution passed through the solvent into the electrolyte,


id: isakidd-refining-technology-20260505-3
file: data/en.wikipedia.org/wiki/IsaKidd_refining_technology-3.md
category: reference
title: IsaKidd refining technology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/IsaKidd_refining_technology
date_saved: 2026-05-05T10:48:44.550207+00:00
instance: kb-cron
parent: isakidd-refining-technology-20260505-0
summary:
This was achieved by machining a 90° “V”-groove into the bottom edge of the cathode. The groove weakens the structure of the copper growing at the bottom edge of the cathode plate because the copper crystals grow perpendicular to the cathode plate from opposite sides of the groove, causing them to intersect at right angles to each other. A discontinuity in the structure is formed at the intersection that results in a weak zone, along which the copper splits during stripping. Figure 4 is a microscope view of the cross-section a copper cathode growing at the tip of a cathode plate. The yellow lines show the orientation and direction of crystal growth. ==== Low-resistance cathodes ==== The standard Isa Process cathodes have slightly higher electrical resistance than solid-copper hanger bar systems used by the Kidd Process, meaning that there is a higher power cost. However, this cost is offset by greater reliability and predictability in the increase in resistance over time, allowing for maintenance planning. The solid-copper hanger bars, on the other hand, lose electrical performance over a shorter period of time due to corrosive attack on the joint and sudden failure is possible. The maintenance costs of such systems


id: isakidd-refining-technology-20260505-4
file: data/en.wikipedia.org/wiki/IsaKidd_refining_technology-4.md
category: reference
title: IsaKidd refining technology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/IsaKidd_refining_technology
date_saved: 2026-05-05T10:48:44.550207+00:00
instance: kb-cron
parent: isakidd-refining-technology-20260505-0
summary:
=== The birth of the combined IsaKidd technology === After Falconbridge’s 1992 decision to market the Kidd technology, the Falconbridge and the then MIM Process Technologies groups competed for the tank house technology market. Between 1992 and 2006, 25 Kidd technology licences were sold, while there were 52 Isa process licences sold in the same period. Xstrata plc (now Glencore) took over MIM Holdings in 2003. The Isa Process technology continued to be developed and marketed by Xstrata Technology. Xstrata subsequently took over Falconbridge in 2006. The Kidd Process technology consequently became part of the Xstrata Technology tank house package and together they began to be marketed as IsaKidd, a name that represents the dual heritage of the technology. The result has been a technology package that combined what were mutually regarded as the best of both versions. This combination led to the development of new stripping systems and new cathode designs are in development. The variation in copper deposits on the cathode plates was one of the difficulties encountered with the earlier stripping machines. Areas of thin copper on the cathode plates, which are caused by short circuits, are difficult to separate from the stainless steel plate due to


id: isothermal-microcalorimetry-20260505-0
file: data/en.wikipedia.org/wiki/Isothermal_microcalorimetry-0.md
category: reference
title: Isothermal microcalorimetry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Isothermal_microcalorimetry
date_saved: 2026-05-05T10:48:45.754826+00:00
instance: kb-cron
parent: isothermal-microcalorimetry-20260505-0
summary:
Isothermal microcalorimetry (IMC) is a laboratory method for real-time monitoring and dynamic analysis of chemical, physical and biological processes. Over a period of hours or days, IMC determines the onset, rate, extent and energetics of such processes for specimens in small ampoules (e.g. 3–20 ml) at a constant set temperature (c. 15 °C–150 °C). IMC accomplishes this dynamic analysis by measuring and recording vs. elapsed time the net rate of heat flow (μJ/s = μW) to or from the specimen ampoule, and the cumulative amount of heat (J) consumed or produced. IMC is a powerful and versatile analytical tool for four closely related reasons: All chemical and physical processes are either exothermic or endothermic—produce or consume heat. The rate of heat flow is proportional to the rate of the process taking place. IMC is sensitive enough to detect and follow either slow processes (reactions proceeding at a few % per year) in a few grams of material, or processes which generate minuscule amounts of heat (e.g. metabolism of a few thousand living cells). IMC instruments generally have a huge dynamic range—heat flows as low as ca. 1 μW and as high as ca. 50,000 μW can be measured by the


id: isothermal-microcalorimetry-20260505-1
file: data/en.wikipedia.org/wiki/Isothermal_microcalorimetry-1.md
category: reference
title: Isothermal microcalorimetry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Isothermal_microcalorimetry
date_saved: 2026-05-05T10:48:45.754826+00:00
instance: kb-cron
parent: isothermal-microcalorimetry-20260505-0
summary:
However, for most applications it is paramount to know, by some means, what process or processes are being measured by monitoring heat flow. In general this entails first having detailed physical, chemical and biological knowledge of the items placed in an IMC ampoule before it is placed in an IMC instrument for evaluation of heat flow over time. It is also then necessary to analyze the ampoule contents after IMC measurements of heat flow have been made for one or more periods of time. Also, logic-based variations in ampoule contents can be used to identify the specific source or sources of heat flow. When rate process and heat flow relationships have been established, it is then possible to rely directly on the IMC data. What IMC can measure in practice depends in part on specimen dimensions, and they are necessarily constrained by instrument design. A given commercial instrument typically accepts specimens of up to a fixed diameter and height. Instruments accepting specimens with dimensions of up to ca. 1 or 2 cm in diameter × ca. 5 cm in height are typical. In a given instrument larger specimens of a given type usually produce greater heat flow signals, and this


id: isothermal-microcalorimetry-20260505-2
file: data/en.wikipedia.org/wiki/Isothermal_microcalorimetry-2.md
category: reference
title: Isothermal microcalorimetry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Isothermal_microcalorimetry
date_saved: 2026-05-05T10:48:45.754826+00:00
instance: kb-cron
parent: isothermal-microcalorimetry-20260505-0
summary:
== Instruments and measurement principles == === Instrument configurations === Modern IMC instruments are actually semi-adiabatic—i.e. heat transfer between the specimen and its surroundings is not zero (adiabatic), because IMC measurement of heat flow depends on the existence of a small temperature differential—ca. 0.001 °C. However, because the differential is so low, IMC measurements are essentially isothermal. Fig. 3. shows an overview of an IMC instrument which contains 48 separate heat flow measurement modules. One module is shown. The module's measuring unit is typically a Peltier-Seebeck device. The device produces a voltage proportional to the temperature difference between a specimen which is producing or consuming heat and a thermally inactive reference which is at the temperature of the heat sink. The temperature difference is in turn proportional to the rate at which the specimen is producing or consuming heat (see Calibration below). All the modules in an instrument use the same heat sink and thermostat and thus all produce data at the same set temperature. However, it is generally possible to start and stop measurements in each ampoule independently. In a highly parallel (e.g. 48-channel) instrument like the one shown in Fig. 3, this makes it possible to perform (start


id: isothermal-microcalorimetry-20260505-3
file: data/en.wikipedia.org/wiki/Isothermal_microcalorimetry-3.md
category: reference
title: Isothermal microcalorimetry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Isothermal_microcalorimetry
date_saved: 2026-05-05T10:48:45.754826+00:00
instance: kb-cron
parent: isothermal-microcalorimetry-20260505-0
summary:
=== Ampoules === Many highly useful IMC measurements can be conducted in sealed ampoules (Fig. 1) which offer advantages of simplicity, protection from contamination and (where needed) a substantial margin of bio-safety for persons handling or exposed to the ampoules. A closed ampoule can contain any desired combination of solids, liquids, gasses or items of biologic origin. Initial gas composition in the ampoule head space can be controlled by sealing the ampoule in the desired gas environment. However, there are also IMC instrument/ampoule designs which permit controlled flow of gas or liquid through the ampoule during measurement and/or mechanical stirring. Also, with proper accessories, some IMC instruments can be operated as ITC (isothermal titration calorimetry) instruments. The topic of ITC is covered elsewhere (see Isothermal titration calorimetry). In addition some IMC instruments can record heat flow while the temperature is slowly changed (scanned) over time. The scanning rate has to be slow (ca. ± 2 °C/h) in order to keep IMC-scale specimens (e.g. a few grams) sufficiently close to the heat sink temperature (< ca. 0.1 °C). Fast scanning of temperature is the province of differential scanning calorimetry (DSC) instruments which generally use much smaller specimens. Some DSC instruments can


id: isothermal-microcalorimetry-20260505-4
file: data/en.wikipedia.org/wiki/Isothermal_microcalorimetry-4.md
category: reference
title: Isothermal microcalorimetry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Isothermal_microcalorimetry
date_saved: 2026-05-05T10:48:45.754826+00:00
instance: kb-cron
parent: isothermal-microcalorimetry-20260505-0
summary:
==== Simple ==== For comparisons of the effect of experimental variables (e.g. initial concentrations) on rate processes, IMC does not require development and use of chemical or other assay methods. If absolute data are required (e.g. quantity of product produced by a process), then assays can be conducted in parallel on specimens identical to those used for IMC (and/or on IMC specimens after IMC runs). The resultant assay data is used to calibrate the rate data obtained by IMC. ==== Non-interfering ==== IMC does not require adding markers (e.g. fluorescent or radioactive substances) to capture rate processes. Unadulterated specimens can be used, and after an IMC run, the specimen is unchanged (except by the processes which have taken place). The post-IMC specimen can be subjected to any kind of physical, chemical, morphological or other evaluation of interest. === Caveats === ==== Missed data ==== As indicated in the methodology description, when the IMC method of inserting a sealed ampoule is used, it is not possible to capture heat flow during the first ca. 40 minutes while the specimen is slowly being brought to the set temperature. In this mode therefore, IMC is best suited to studying processes which start slowly


id: isothermal-microcalorimetry-20260505-5
file: data/en.wikipedia.org/wiki/Isothermal_microcalorimetry-5.md
category: reference
title: Isothermal microcalorimetry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Isothermal_microcalorimetry
date_saved: 2026-05-05T10:48:45.754826+00:00
instance: kb-cron
parent: isothermal-microcalorimetry-20260505-0
summary:
===== Formation ===== IMC is widely used for studying the rates of formation of a variety of materials by various processes. It is best suited to study processes which occur slowly—i.e. over hours or days. A prime example is the study of hydration and setting reactions of calcium mineral cement formulations. One paper provides an overview (Gawlicki, et al. 2010) and another describes a simple approach (Evju 2003). Other studies focus on insights into cement hydration provided by IMC combined with IR spectroscopy (Ylmen et al. 2010) and on using IMC to study the influence of compositional variables on cement hydration and setting times (Xu et al. 2011). IMC can also be conveniently used to study the rate and amount of hydration (in air of known humidity) of calcium minerals or other minerals. To provide air of known humidity for such studies, small containers of saturated salt solutions can be placed in an IMC ampoule along with a non-hydrated mineral specimen. The ampoule is then sealed and introduced into an IMC instrument. The saturated salt solution keeps the air in the ampoule at a known rH, and various common salt solutions provide humidities ranging from e.g. 32-100% rH. Such studies


id: isothermal-microcalorimetry-20260505-6
file: data/en.wikipedia.org/wiki/Isothermal_microcalorimetry-6.md
category: reference
title: Isothermal microcalorimetry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Isothermal_microcalorimetry
date_saved: 2026-05-05T10:48:45.754826+00:00
instance: kb-cron
parent: isothermal-microcalorimetry-20260505-0
summary:
===== Cell and tissue biology ===== Mammalian cells in culture have a metabolic rate of ca. 30×10−12 W/cell (Figs. 2 and 3 in Bibliography: West, Woodruff and Brown 2002). By definition, IMC instruments have a sensitivity of at least 1×10−6 W (i.e. 1 μW). Therefore, the metabolic heat of ca. 33,000 cells is detectable. Based on this sensitivity, IMC was used to perform a large number of pioneering studies of cultured mammalian cell metabolismics in the 1970s and 1980s in Sweden. One paper (Monti 1990) serves as an extensive guide to work done up until 1990. It includes explanatory text and 42 references to IMC studies of heat flow from cultured human erythrocytes, platelets, lymphocytes, lymphoma cells, granulocytes, adipocytes, skeletal muscle, and myocardial tissue. The studies were done to determine how and where IMC might be used as a clinical diagnostic method and/or provide insights into metabolic differences between cells from healthy persons and persons with various diseases or health problems. Developments since ca. 2000 in IMC (e.g. massively parallel instruments, real-time, computer-based storage and analysis of heat flow data) have stimulated further use of IMC in cultured cell biology. For example, IMC has been evaluated for assessing antigen-induced lymphocyte


id: isothermal-microcalorimetry-20260505-7
file: data/en.wikipedia.org/wiki/Isothermal_microcalorimetry-7.md
category: reference
title: Isothermal microcalorimetry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Isothermal_microcalorimetry
date_saved: 2026-05-05T10:48:45.754826+00:00
instance: kb-cron
parent: isothermal-microcalorimetry-20260505-0
summary:
"The cytotoxicity of particulate materials such as bioactive glass and hydroxyapatite particles can be evaluated using the microcalorimetry method. This is a modern method for in vitro study of biomaterials biocompatibility and cytotoxicity which can be used alongside the old conventional assays." ===== Microbiology ===== Publications describing use of IMC in microbiology began in the 1980s (Jesperson 1982). While some IMC microbiology studies have been directed at viruses (Heng et al. 2005) and fungi (Antoci et al. 1997), most have been concerned with bacteria. A recent paper (Braissant et al. 2010) provides a general introduction to IMC metabolismic methods in microbiology and an overview of applications in medical and environmental microbiology. The paper also explains how heat flow vs. time data for bacteria in culture are an exact expression—as they occur over time—of the fluctuations in microorganism metabolic activity and replication rates in a given medium (Fig. 6). In general, bacteria are about 1/10 the size of mammalian cells and produce perhaps 1/10 as much metabolic heat-i.e. ca. 3×10−12 W/cell. Thus, compared to mammalian cells (see above) ca. 10X as many bacteria—ca. 330,000—must be present to produce detectable heat flow—i.e. 1 μW. However, many bacteria replicate orders of magnitude more


id: isothermal-microcalorimetry-20260505-8
file: data/en.wikipedia.org/wiki/Isothermal_microcalorimetry-8.md
category: reference
title: Isothermal microcalorimetry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Isothermal_microcalorimetry
date_saved: 2026-05-05T10:48:45.754826+00:00
instance: kb-cron
parent: isothermal-microcalorimetry-20260505-0
summary:
===== Environmental biology ===== Because of its versatility, IMC can be an effective tool in the fields of plant and environmental biology. In an early study (Hansen et al. 1989), the metabolic rate of larch tree clone tissue specimens was measured. The rate was predictive of long-term tree growth rates, was consistent for specimens from a given tree and was found to correlate with known variations in the long-term growth of clones from different trees. Bacterial oxalotrophic metabolism is common in the environment, particularly in soils. Oxalotrophic bacteria are capable of using oxalate as a sole carbon and energy source. Closed-ampoule IMC was used to study metabolism of oxalotrophic soil bacteria exposed to both an optimized medium containing potassium oxalate as the sole carbon source and a model soil (Bravo et al. 2011). Using an optimized medium, growth of six different strains of soil bacteria was easily monitored and reproducibly quantified and differentiated over a period days. IMC measurement of bacterial metabolic heat flow in the model soil was more difficult, but a proof of concept was demonstrated. Moonmilk is a white, creamy material found in caves. It is a non-hardening, fine crystalline precipitate from limestone and is composed mainly


id: kraft-process-20260505-0
file: data/en.wikipedia.org/wiki/Kraft_process-0.md
category: reference
title: Kraft process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kraft_process
date_saved: 2026-05-05T10:48:46.929805+00:00
instance: kb-cron
parent: kraft-process-20260505-0
summary:
The kraft process (also known as kraft pulping or sulfate process) is a process for conversion of wood into wood pulp, which consists of almost pure cellulose fibres, the main component of paper. The kraft process involves treatment of wood chips with a hot mixture of water, sodium hydroxide (NaOH), and sodium sulfide (Na2S), known as white liquor, that breaks the bonds that link lignin, hemicellulose, and cellulose. The technology entails several steps, both mechanical and chemical. It is the dominant method for producing paper. In some situations, the process has been controversial because kraft plants can release odorous products and in some situations produce substantial liquid wastes. The process name is derived from the German word Kraft, meaning 'strength' in this context, due to the strength of the kraft paper produced using this process. == History == A precursor of the kraft process was used during the Napoleonic Wars in England. The kraft process was invented by Carl F. Dahl in 1879 in Danzig, Prussia, Germany. U.S. patent 296,935 was issued in 1884, and a pulp mill using this technology began in Sweden in 1890. The invention of the recovery boiler by G. H. Tomlinson in the early 1930s


id: kraft-process-20260505-1
file: data/en.wikipedia.org/wiki/Kraft_process-1.md
category: reference
title: Kraft process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kraft_process
date_saved: 2026-05-05T10:48:46.929805+00:00
instance: kb-cron
parent: kraft-process-20260505-0
summary:
4. CaO + H2O → Ca(OH)2 The combination of reactions 1 through 4 form a closed cycle with respect to sodium, sulfur and calcium and is the main concept of the so-called recausticizing process where sodium carbonate is reacted to regenerate sodium hydroxide. The recovery boiler also generates high pressure steam which is fed to turbogenerators, reducing the steam pressure for the mill use and generating electricity. A modern kraft pulp mill is more than self-sufficient in its electrical generation and normally will provide a net flow of energy which can be used by an associated paper mill or sold to neighboring industries or communities through to the local electrical grid. Additionally, bark and wood residues are often burned in a separate power boiler to generate steam. Although recovery boilers using G.H. Tomlinson's invention have been in general use since the early 1930s, attempts have been made to find a more efficient process for the recovery of cooking chemicals. Weyerhaeuser has operated a Chemrec first generation black liquor entrained flow gasifier successfully at its New Bern plant in North Carolina, while a second generation plant is run in pilot scale at Smurfit Kappa's plant in Piteå, Sweden. An additional technology


id: kraft-process-20260505-2
file: data/en.wikipedia.org/wiki/Kraft_process-2.md
category: reference
title: Kraft process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kraft_process
date_saved: 2026-05-05T10:48:46.929805+00:00
instance: kb-cron
parent: kraft-process-20260505-0
summary:
== Comparison with other pulping processes == Pulp produced by the kraft process is stronger than that made by other pulping processes and maintains a high effective sulfur ratio (sulfidity), an important determiner of the strength of the paper. Acidic sulfite processes degrade cellulose more than the kraft process, which leads to weaker fibers. Kraft pulping removes most of the lignin present originally in the wood whereas mechanical pulping processes leave most of the lignin in the fibers. The hydrophobic nature of lignin interferes with the formation of the hydrogen bonds between cellulose (and hemicellulose) in the fibers needed for the strength of paper (strength refers to tensile strength and resistance to tearing). Kraft pulp is darker than other wood pulps, but it can be bleached to make very white pulp. Fully bleached kraft pulp is used to make high-quality paper where strength, whiteness, and resistance to yellowing are important. Kraft pulp's high cellulose and low lignin content is suited for paper for printing and writing, In contrast, mechanical pulp is produced by grinding wood without removing lignin. The lignin retained in mechanical pulp provides the opacity and bulk necessary for newsprint, but it results in lower tensile strength and


id: kroll-process-20260505-0
file: data/en.wikipedia.org/wiki/Kroll_process-0.md
category: reference
title: Kroll process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kroll_process
date_saved: 2026-05-05T10:48:48.073653+00:00
instance: kb-cron
parent: kroll-process-20260505-0
summary:
The Kroll process is a pyrometallurgical industrial process used to produce metallic titanium from titanium tetrachloride. As of 2001 William Justin Kroll's process replaced the Hunter process for almost all commercial production. == Process == In the Kroll process, titanium tetrachloride is reduced by liquid magnesium to give titanium metal: TiCl 4 + 2 Mg → 825 ∘ C Ti + 2 MgCl 2 {\displaystyle {\ce {{TiCl4}+2{Mg}->[825~^{\circ }\mathrm {C} ]{Ti}+2{MgCl2}}}} The reduction is conducted at 800–850 °C in a stainless steel retort. Complications result from partial reduction of the TiCl4, giving to the lower chlorides TiCl2 and TiCl3. The MgCl2 can be further refined back to magnesium. === Appurtenant processes === The resulting porous metallic titanium sponge is purified by leaching or vacuum distillation. The sponge is crushed, and pressed before it is melted in a consumable electrode vacuum arc furnace, "backfilled with pure gettered argon of a pressure high enough to avoid a glow discharge". The melted ingot is allowed to solidify under vacuum. It is often remelted to remove inclusions and ensure uniformity. These melting steps add to the cost of the product. Titanium is about six times as expensive as stainless steel: Potter noted in 2023 that


id: krupp-renn-process-20260505-0
file: data/en.wikipedia.org/wiki/Krupp–Renn_process-0.md
category: reference
title: Krupp–Renn process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Krupp–Renn_process
date_saved: 2026-05-05T10:48:49.362759+00:00
instance: kb-cron
parent: krupp-renn-process-20260505-0
summary:
The Krupp–Renn process was a direct reduction steelmaking process used from the 1930s to the 1970s. It used a rotary furnace and was one of the few technically and commercially successful direct reduction processes in the world, acting as an alternative to blast furnaces due to their coke consumption. The Krupp–Renn process consumed mainly hard coal and had the unique characteristic of partially melting the charge. This method is beneficial for processing low-quality or non-melting ores, as their waste material forms a protective layer that can be easily separated from the iron. It generates Luppen, nodules of pre-reduced iron ore, which can be easily melted down. The first industrial furnaces emerged in the 1930s, firstly in Nazi Germany and then in the Japanese Empire. During the 1950s, new facilities were constructed, notably in Czechoslovakia and West Germany. The process was discontinued in the early 1970s, with a few nuances. It was unproductive, intricate to master, and only pertinent to certain ores. In the beginning of the 21st century, Japan modernized the process to manufacture ferronickel, which is the sole surviving variant. == History == === Setting up === The direct reduction of iron ore principle was tested in the late


id: krupp-renn-process-20260505-1
file: data/en.wikipedia.org/wiki/Krupp–Renn_process-1.md
category: reference
title: Krupp–Renn process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Krupp–Renn_process
date_saved: 2026-05-05T10:48:49.362759+00:00
instance: kb-cron
parent: krupp-renn-process-20260505-0
summary:
The Krupp–Renn process is a direct reduction process that uses a long tubular furnace similar to those found in cement production. The most recent units constructed have a diameter of approximately 4.5 meters and a length of 110 meters. The residence time of the product is influenced by the slope and speed of rotation of the rotary kiln, which is inclined at an angle of roughly 2.5 percent. Prior to usage, the iron ore is crushed to less than 6 mm in particle size. The iron ore is introduced into the furnace upstream and mixed with a small amount of fuel, typically hard coal. After 6 to 8 hours, it exits the furnace as pre-reduced iron ore at 1,000 °C. The amount of iron recovered ranges from 94% to 97.5% of the initial iron in the ore. A burner located at the lower end of the furnace provides heat, transforming it into a counter-current reactor. The fuel comprises finely pulverized coal, which, upon high-temperature combustion, generates reducing gas primarily consisting of CO. Once the furnace reaches an optimal temperature, the ore-coal mixture can serve as the primary fuel source. The fumes exiting the furnace's upper end attain temperatures ranging from


id: krupp-renn-process-20260505-2
file: data/en.wikipedia.org/wiki/Krupp–Renn_process-2.md
category: reference
title: Krupp–Renn process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Krupp–Renn_process
date_saved: 2026-05-05T10:48:49.362759+00:00
instance: kb-cron
parent: krupp-renn-process-20260505-0
summary:
The furnace comprises three distinct zones: Firstly, the preheating zone heats the ore to 800 °C using the hot fumes within the furnace. Ore reduction occurs only if temperatures exceed 900-1,000 °C, while the coal releases its most volatile constituents. Secondly, the reduction zone is situated in the middle of the furnace, where coal and iron oxides combine to produce carbon monoxide. The carbon monoxide is released from the charge, generating a gaseous layer that shields the charge against the oxidizing air circulating above. As a consequence, this excessive gas is combusted, raising the temperature of the furnace walls, which then transfer the heat back to the charge due to rotary motion. The temperature eventually increases to 800 – 1,200 °C. Subsequently, the iron oxides are gradually altered into ferronickel or metallic iron. The metal produced is in the form of metallic sponge particles that are finely dispersed in the powdery gangue. Reduction is complete by the end of the furnace, and there is a minimal amount of CO produced. This is due to the fact that the charge is no longer protected from oxidation by the air blown in at the base of the furnace. As a result, a


id: krupp-renn-process-20260505-3
file: data/en.wikipedia.org/wiki/Krupp–Renn_process-3.md
category: reference
title: Krupp–Renn process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Krupp–Renn_process
date_saved: 2026-05-05T10:48:49.362759+00:00
instance: kb-cron
parent: krupp-renn-process-20260505-0
summary:
=== Productivity === Depending on the ore and plant size, a furnace can daily output 250 to 800 tons of pre-reduced iron ore. The biggest furnaces, up to 5 meters in diameter and 110 meters long, can process 950 to 1,000 tons of ore daily, excluding fuel. A properly operated plant typically runs for around 300 days per year. The internal refractory typically lasts 7 to 8 months in the most exposed part of the furnace and for 2 years elsewhere. In 1960, a Krupp-Renn furnace using low-grade ore yielded 100 kilotons of iron annually, while a contemporaneous modern blast furnace produced ten times as much cast iron. Direct reduction processes employing rotary furnaces frequently face a significant challenge due to the localized formation of iron and slag rings, which sinter together and gradually obstruct the furnace. Understanding the mechanism of lining formation is a complex process involving mineralogy, chemical reactions, and ore preparation. The formation of the lining ring, which progressively grows and poisons the furnace, is caused by a few elements in minute quantities. To remedy this, increasing the supply of combustion air or interrupting the furnace charging process are effective solutions. Otherwise, it may be necessary to


id: krupp-renn-process-20260505-4
file: data/en.wikipedia.org/wiki/Krupp–Renn_process-4.md
category: reference
title: Krupp–Renn process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Krupp–Renn_process
date_saved: 2026-05-05T10:48:49.362759+00:00
instance: kb-cron
parent: krupp-renn-process-20260505-0
summary:
The production of ferronickel from laterites takes place in a context that is much more favorable to the Krupp–Renn process than to the steel industry. Lateritic ores in the form of saprolite are poor, very basic and contain iron. Production volumes are moderate, and the nickel chemistry is remarkably amenable to rotary kiln reduction. The process is therefore attractive, but regardless of the metal extracted, mastering all the physical and chemical transformations in a single reactor is a real challenge. The failure of the Larco plant at Lárymna Greece, illustrates the risk involved in adopting this process: it was only when the ore was ready for industrial processing that it proved incompatible with the Krupp–Renn process. As a result, lower-temperature reduction followed by electric furnace smelting allows each stage to have its own dedicated tool for greater simplicity and efficiency. Developed in 1950 at Koniambo in New Caledonia, this combination has proven to be both cost-effective and, above all, more robust. Large rotating drums (5 m in diameter and 100 m or even 185 m long) are used to produce a dry powder from nickel ore concentrate. This powder contains 1.5 to 3% nickel. It leaves the drum at 800–900


id: kv-rner-process-20260505-0
file: data/en.wikipedia.org/wiki/Kværner_process-0.md
category: reference
title: Kværner process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kværner_process
date_saved: 2026-05-05T10:48:50.554847+00:00
instance: kb-cron
parent: kv-rner-process-20260505-0
summary:
The Kværner process or the Kværner carbon black and hydrogen process (CB&H) is a method of producing carbon black and hydrogen gas from hydrocarbons such as methane, natural gas and biogas with no greenhouse gas pollution. The process was developed in the 1980s by the Norwegian engineering firm Kværner, and was first commercially exploited in 1999. Further refinement enabled the methane pyrolysis process for implementation at high-volume and low-cost. == Description == The endothermic reaction separates (i.e. decomposes) hydrocarbons into carbon and hydrogen in a plasma burner at around 1600 °C. The resulting components, carbon particles and hydrogen, are present as a mixture in form of an aerosol. C n H m ⟶ n C + m 2 H 2 {\displaystyle {\ce {C_{\mathit {n}}H_{\mathit {m}}->{{\mathit {n}}C}+{\frac {\mathit {m}}{2}}H2}}} In comparison to other reformation methods such as steam reforming and partial oxidation that have carbon dioxide as a by-product, there is no by-product in the Kværner process. The natural gas is efficiently and completely transformed into pure carbon and hydrogen and does not release carbon dioxide into the atmosphere. After separating the mixture, the carbon particles can be used for instance as activated carbon, graphite or industrial soot, special kinds of


id: leblanc-process-20260505-0
file: data/en.wikipedia.org/wiki/Leblanc_process-0.md
category: reference
title: Leblanc process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Leblanc_process
date_saved: 2026-05-05T10:48:51.792778+00:00
instance: kb-cron
parent: leblanc-process-20260505-0
summary:
The Leblanc process was an early industrial process for making soda ash (sodium carbonate) used throughout the 19th century, named after its inventor, Nicolas Leblanc. It involved two stages: making sodium sulfate from sodium chloride, followed by reacting the sodium sulfate with coal and calcium carbonate to make sodium carbonate. The process gradually became obsolete after the development of the Solvay process. == Background == Soda ash (sodium carbonate) and potash (potassium carbonate), collectively termed alkali, are vital chemicals in the glass, textile, soap, and paper industries. The traditional source of alkali in western Europe had been potash obtained from wood ashes. However, by the 13th century, deforestation had rendered this means of production uneconomical, and alkali had to be imported. Potash was imported from North America, Scandinavia, and Russia, where large forests still stood. Soda ash was imported from Spain and the Canary Islands, where it was produced from the ashes of glasswort plants (called barilla ashes in Spain), or imported from Syria. The soda ash from glasswort plant ashes was mainly a mixture of sodium carbonate and potassium carbonate. In addition in Egypt, naturally occurring sodium carbonate, the mineral natron, was mined from dry lakebeds. In Britain, the


id: leblanc-process-20260505-1
file: data/en.wikipedia.org/wiki/Leblanc_process-1.md
category: reference
title: Leblanc process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Leblanc_process
date_saved: 2026-05-05T10:48:51.792778+00:00
instance: kb-cron
parent: leblanc-process-20260505-0
summary:
== Industrial history == Leblanc established the first Leblanc process plant in 1791 in St. Denis. However, French Revolutionaries seized the plant, along with the rest of Louis Philip's estate, in 1794, and publicized Leblanc's trade secrets. Napoleon I returned the plant to Leblanc in 1801, but lacking the funds to repair it and compete against other soda works that had been established in the meantime, Leblanc committed suicide in 1806. By the early 19th century, French soda ash producers were making 10,000 - 15,000 tons annually. However, it was in Britain that the Leblanc process became most widely practiced. The first British soda works using the Leblanc process was built by the Losh family of iron founders at the Losh, Wilson and Bell works in Walker on the River Tyne in 1816, but steep British tariffs on salt production hindered the economics of the Leblanc process and kept such operations on a small scale until 1824. Following the repeal of the salt tariff, the British soda industry grew dramatically. The Bonnington Chemical Works was possibly the earliest production, and the chemical works established by James Muspratt in Liverpool and Flint, and by Charles Tennant near Glasgow became some of


id: leblanc-process-20260505-2
file: data/en.wikipedia.org/wiki/Leblanc_process-2.md
category: reference
title: Leblanc process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Leblanc_process
date_saved: 2026-05-05T10:48:51.792778+00:00
instance: kb-cron
parent: leblanc-process-20260505-0
summary:
== Pollution issues == The Leblanc process plants were quite damaging to the local environment. The process of generating salt cake from salt and sulfuric acid released hydrochloric acid gas, and because this acid was industrially useless in the early 19th century, it was simply vented into the atmosphere. Also, an insoluble smelly solid waste was produced. For every 8 tons of soda ash, the process produced 5.5 tons of hydrogen chloride and 7 tons of calcium sulfide waste. This solid waste (known as galligu) had no economic value, and was piled in heaps and spread on fields near the soda works, where it weathered to release hydrogen sulfide, the toxic gas responsible for the odor of rotten eggs. Because of their noxious emissions, Leblanc soda works became targets of lawsuits and legislation. An 1839 suit against soda works alleged, "the gas from these manufactories is of such a deleterious nature as to blight everything within its influence, and is alike baneful to health and property. The herbage of the fields in their vicinity is scorched, the gardens neither yield fruit nor vegetables; many flourishing trees have lately become rotten naked sticks. Cattle and poultry droop and pine away. It


id: linde-frank-caro-process-20260505-0
file: data/en.wikipedia.org/wiki/Linde–Frank–Caro_process-0.md
category: reference
title: Linde–Frank–Caro process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Linde–Frank–Caro_process
date_saved: 2026-05-05T10:48:52.991241+00:00
instance: kb-cron
parent: linde-frank-caro-process-20260505-0
summary:
The Linde–Frank–Caro process is a method for hydrogen production by removing hydrogen and carbon dioxide from water gas by condensation. The process was invented in 1909 by Adolf Frank and developed with Carl von Linde and Heinrich Caro. == Process description == Water gas is compressed to 20 bar and pumped into the Linde–Frank–Caro reactor. A water column removes most of the carbon dioxide and sulfur. Tubes with caustic soda then remove the remaining carbon dioxide, sulphur, and water from the gas stream. The gas enters a chamber and is cooled to −190 °C, resulting in the condensation of most of the gas to a liquid. The remaining gas is pumped to the next vessel where the nitrogen is liquefied by cooling to −205 °C, resulting in hydrogen gas as an end product. == See also == Water gas shift reaction Timeline of hydrogen technologies Frank–Caro process, another process used to produce cyanamide from calcium carbide and nitrogen gas in an electric furnace == References ==


id: list-of-purification-methods-in-chemistry-20260505-0
file: data/en.wikipedia.org/wiki/List_of_purification_methods_in_chemistry-0.md
category: reference
title: List of purification methods in chemistry
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/List_of_purification_methods_in_chemistry
date_saved: 2026-05-05T10:48:54.214659+00:00
instance: kb-cron
parent: list-of-purification-methods-in-chemistry-20260505-0
summary:
Purification in a chemical context is the physical separation of a chemical substance of interest from foreign or contaminating substances. Pure results of a successful purification process are termed isolate. The following list of chemical purification methods should not be considered exhaustive. Affinity purification purifies proteins by retaining them on a column through their affinity to antibodies, enzymes, or receptors that have been immobilised on the column. Filtration is a mechanical method to separate solids from liquids or gases by passing the feed stream through a porous sheet such as a cloth or membrane, which retains the solids and allows the liquid to pass through. Centrifugation is a process that uses an electric motor to spin a vessel of fluid at high speed to make heavier components settle to the bottom of the vessel. Evaporation removes volatile liquids from non-volatile solutes, which cannot be done through filtration due to the small size of the substances. Liquid–liquid extraction removes an impurity or recovers a desired product by dissolving the crude material in a solvent in which other components of the feed material are soluble. Crystallization separates a product from a liquid feed stream, often in extremely pure form, by cooling the


id: list-of-wastewater-treatment-technologies-20260505-0
file: data/en.wikipedia.org/wiki/List_of_wastewater_treatment_technologies-0.md
category: reference
title: List of wastewater treatment technologies
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/List_of_wastewater_treatment_technologies
date_saved: 2026-05-05T10:48:55.394309+00:00
instance: kb-cron
parent: list-of-wastewater-treatment-technologies-20260505-0
summary:
This page consists of a list of wastewater treatment technologies: == See also == Agricultural wastewater treatment Industrial wastewater treatment List of solid waste treatment technologies Waste treatment technologies Water purification Sewage sludge treatment == References ==


id: chemical-looping-combustion-20260505-0
file: data/en.wikipedia.org/wiki/Chemical_looping_combustion-0.md
category: reference
title: Chemical looping combustion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Chemical_looping_combustion
date_saved: 2026-05-05T10:48:56.584534+00:00
instance: kb-cron
parent: chemical-looping-combustion-20260505-0
summary:
Chemical looping combustion (CLC) is a technological process typically employing a dual fluidized bed system. CLC operated with an interconnected moving bed with a fluidized bed system, has also been employed as a technology process. In CLC, a metal oxide is employed as a bed material providing the oxygen for combustion in the fuel reactor. The reduced metal is then transferred to the second bed (air reactor) and re-oxidized before being reintroduced back to the fuel reactor completing the loop. Fig 1 shows a simplified diagram of the CLC process. Fig 2 shows an example of a dual fluidized bed circulating reactor system and a moving bed-fluidized bed circulating reactor system. Isolation of the fuel from air simplifies the number of chemical reactions in combustion. Employing oxygen without nitrogen and the trace gases found in air eliminates the primary source for the formation of nitrogen oxide (NOx), produces a flue gas composed primarily of carbon dioxide and water vapor; other trace pollutants depend on the fuel selected. == Description == Chemical looping combustion (CLC) uses two or more reactions to perform the oxidation of hydrocarbon-based fuels. In its simplest form, an oxygen-carrying species (normally a metal) is first oxidized in


id: chemical-looping-combustion-20260505-1
file: data/en.wikipedia.org/wiki/Chemical_looping_combustion-1.md
category: reference
title: Chemical looping combustion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Chemical_looping_combustion
date_saved: 2026-05-05T10:48:56.584534+00:00
instance: kb-cron
parent: chemical-looping-combustion-20260505-0
summary:
=== Variants and related technologies === A variant of CLC is Chemical-Looping Combustion with Oxygen Uncoupling (CLOU) where an oxygen carrier is used that releases gas-phase oxygen in the fuel reactor, e.g. CuO/Cu2O. This is helpful for achieving high gas conversion, and especially when using solid fuels, where slow steam gasification of char can be avoided. CLOU operation with solid fuels shows high performance Chemical Looping can also be used to produce hydrogen in Chemical-Looping Reforming (CLR) processes. In one configuration of the CLR process, hydrogen is produced from coal and/or natural gas using a moving bed fuel reactor integrated with a steam reactor and a fluidized bed air reactor. This configuration of CLR can produce greater than 99% purity H2 without the need for CO2 separation. Another CLR process is based on conventional steam methane reforming (SMR), with chemical-looping combustion replacing the reformer furnace. Thus, the heat for the reforming is transferred in fluidized-bed heat exchangers (FBHEs) connected to the air reactor and the fuel used is the off-gas from the reforming plus additional methane. This configuration can give higher energy efficiency than conventional SMR, because the furnace temperature can be reduced. Consequently, a negative CO2 capture cost could


id: chemical-looping-reforming-and-gasification-20260505-0
file: data/en.wikipedia.org/wiki/Chemical_looping_reforming_and_gasification-0.md
category: reference
title: Chemical looping reforming and gasification
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Chemical_looping_reforming_and_gasification
date_saved: 2026-05-05T10:48:57.792091+00:00
instance: kb-cron
parent: chemical-looping-reforming-and-gasification-20260505-0
summary:
Chemical looping reforming (CLR) and gasification (CLG) are the operations that involve the use of gaseous carbonaceous feedstock and solid carbonaceous feedstock, respectively, in their conversion to syngas in the chemical looping scheme. The typical gaseous carbonaceous feedstocks used are natural gas and reducing tail gas, while the typical solid carbonaceous feedstocks used are coal and biomass. The feedstocks are partially oxidized to generate syngas using metal oxide oxygen carriers as the oxidant. The reduced metal oxide is then oxidized in the regeneration step using air. The syngas is an important intermediate for generation of such diverse products as electricity, chemicals, hydrogen, and liquid fuels. The motivation for developing the CLR and CLG processes lies in their advantages of being able to avoid the use of pure oxygen in the reaction, thereby circumventing the energy intensive air separation requirement in the conventional reforming and gasification processes. The energy conversion efficiency of the processes can, thus, be significantly increased. Steam and carbon dioxide can also be used as the oxidants. As the metal oxide also serves as the heat transfer medium in the chemical looping process, the exergy efficiency of the reforming and gasification processes like that for the combustion process


id: chemical-looping-reforming-and-gasification-20260505-1
file: data/en.wikipedia.org/wiki/Chemical_looping_reforming_and_gasification-1.md
category: reference
title: Chemical looping reforming and gasification
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Chemical_looping_reforming_and_gasification
date_saved: 2026-05-05T10:48:57.792091+00:00
instance: kb-cron
parent: chemical-looping-reforming-and-gasification-20260505-0
summary:
CH4 + H2O → CO + 3H2 Steam can be further used to convert CO to H2 via the water-gas shift reaction (WGS): H2O + CO → CO2 + H2 The SMR reaction is endothermic, which requires heat input. The state-of-art SMR system places the tubular catalytic reactors in a furnace, in which fuel gas is burned to provide the required heat. In the SMR with chemical looping combustion (CLC-SMR) concepts shown in Fig 2, the syngas production is carried out by the SMR in a tubular catalytic reactor while the chemical looping combustion system is used to provide the heat for the catalytic reaction. Depending on which chemical looping reactor is used to provide the SMR reaction heat, two CLC-SMR schemes can be configured. In Scheme 1 (Fig 2a), the reaction heat is provided by the reducer (fuel reactor). In Scheme 2 (Fig 2b), the reaction heat is provided by the combustor (air reactor). In either scheme, the combustion of metal oxide by air in the chemical looping system provides the heat source that sustains the endothermic SMR reactions. In the chemical looping system, natural gas and the recycled off-gas from the pressure swing adsorption (PSA) of the SMR


id: chemical-looping-reforming-and-gasification-20260505-2
file: data/en.wikipedia.org/wiki/Chemical_looping_reforming_and_gasification-2.md
category: reference
title: Chemical looping reforming and gasification
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Chemical_looping_reforming_and_gasification
date_saved: 2026-05-05T10:48:57.792091+00:00
instance: kb-cron
parent: chemical-looping-reforming-and-gasification-20260505-0
summary:
=== Chemical looping gasification (CLG) === Chemical looping gasification (CLG) differs from the CLR in that it uses solid fuels such as coal and biomass instead of gaseous fuels as feedstocks. The operating principles for the CLG is similar to CLR. For solid feedstocks, devolatilization and pyrolysis of the solid fuel occur when the solid fuels are introduced into the reducer and mixed with the oxygen carrier particles. With the fluidized bed reducer, the released volatiles, including light organic compounds and tars, may channel through the reducer and exit with the syngas. The light organic compounds may reduce the purity of the syngas, while the tars may accumulate in downstream pipelines and instruments. For example, the carbon efficiency using the coal CLG fluidized bed reducer may vary from 55% to 81%, whereas the carbon efficiency using the coal moving bed reducer can reach 85% to 98%. The syngas derived from the biomass CLG fluidized bed reducer may consist of up to 15% methane, while the syngas derived from the biomass CLG moving bed reducer can reach a methane concentration of less than 5%. In general, increasing the temperature of the CLG system can promote volatile and char conversion. This may


id: mannheim-process-20260505-0
file: data/en.wikipedia.org/wiki/Mannheim_process-0.md
category: reference
title: Mannheim process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Mannheim_process
date_saved: 2026-05-05T10:48:58.970059+00:00
instance: kb-cron
parent: mannheim-process-20260505-0
summary:
The Mannheim process is an industrial process for the production of hydrogen chloride and sodium sulfate from sulfuric acid and sodium chloride. The Mannheim furnace is also used to produce potassium sulfate from potassium chloride. The Mannheim process is a stage in the Leblanc process for the production of sodium carbonate. == Process == The process is named after Mannheim furnace, a large cast iron kiln in which it is conducted. The furnace was developed at Verein Chemischer Fabriken in Mannheim at the turn of the 20th century and superseded earlier furnace designs formerly used for the same purpose. Sodium chloride and sulfuric acid are first fed onto a stationary reaction plate where an initial reaction takes place. The stationary plate is up to 6 m (20 ft) in diameter. Rotating rabble arms constantly turn over the mixture and move the intermediate product to a lower plate. The kiln portion of the furnace is constructed with bricks that have high resistance to direct flame, temperature, and acid. The other parts of the furnace are heat and acid resistant. Hot flue gas passes up over the plates carrying out liberated hydrogen chloride gas. The intermediate product reacts with more sodium chloride


id: mass-deacidification-20260505-0
file: data/en.wikipedia.org/wiki/Mass_deacidification-0.md
category: reference
title: Mass deacidification
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Mass_deacidification
date_saved: 2026-05-05T10:49:00.170656+00:00
instance: kb-cron
parent: mass-deacidification-20260505-0
summary:
Mass deacidification is a term used in library and information science as one possible measure against the degradation of paper in old books, the so-called "slow fires". The goal of the process is to increase the pH of acidic paper. Although acid-free paper has become more common, a large body of acidic paper still exists in books made after the 1850s; this is because of its cheaper and simpler production methods. Acidic paper, especially when exposed to light, air pollution, or high relative humidity, yellows and becomes brittle over time. During mass deacidification an alkaline agent is deposited in the paper to neutralize existing acid and prevent further decay. Mass deacidification is intended for objects on acidic paper that will be lost if no action is performed. == History of research and process development == Mass deacidification—along with microfilm and lamination—was developed during the early and mid-20th century as a response to the chemical process of hydrolysis by which the fibers that constitute paper, providing its structure and strength, have their bonds broken, resulting in paper that becomes increasingly brittle over time. Environmental pollutants can react with paper to form acids that promote oxidation, creating more acid as a by-product,


id: mass-deacidification-20260505-1
file: data/en.wikipedia.org/wiki/Mass_deacidification-1.md
category: reference
title: Mass deacidification
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Mass_deacidification
date_saved: 2026-05-05T10:49:00.170656+00:00
instance: kb-cron
parent: mass-deacidification-20260505-0
summary:
The BookKeeper process is a non-aqueous, liquid phase process that uses magnesium oxide. BookKeeper is available through Preservation Technologies, L.P. with plants in the U.S., Spain, Japan, Poland, The Netherlands, South Africa, Qatar. Another plant is available through Fratielivi in Italy. The CSC Book Saver uses carbonated magnesium propylate for deacidification. The CSC Book Saver is available in Europe through Conservación de Sustratos Celulósicos S.L. (CSC) (Barcelona, Spain). The Papersave process was developed by Battelle Ingenieurtechnik GmbH and is, therefore, sometimes referred to as "the Battelle Process". The process uses magnesium titanium alkoxide. The Papersave process is available in Europe through Nitrochemie Wimmis (Wimmis, Switzerland) under the name of Papersave Swiss and the Zentrum für Bucherhaltung (Leipzig, Germany). The Wei T'o process uses methoxy magnesium methyl carbonate, or isopropoxy magnesium isopropyl carbonate, and new products are coming out in 2008. Wei T'o is less commonly used for mass deacidification treatment than for single item deacidification. Wei T'o products are available through Wei T'o Associates Inc. (Matteson, US). BookKeeper, CSC Booksaver, Papersave, and Wei T'o are also available as hand-held sprays. == Adoption and costs == While deacidification has been adopted by major research libraries such as the Library of Congress


id: mercury-silvering-20260505-0
file: data/en.wikipedia.org/wiki/Mercury_silvering-0.md
category: reference
title: Mercury silvering
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Mercury_silvering
date_saved: 2026-05-05T10:49:01.355366+00:00
instance: kb-cron
parent: mercury-silvering-20260505-0
summary:
Mercury silvering or fire gilding is a silvering technique for applying a thin layer of precious metal such as silver or gold (mercury gilding) to a base metal object. The process was invented during the renaissance and is documented in Vannoccio Biringuccio's 1540 book De la pirotechnia. An amalgam of mercury and the precious metal is prepared and applied to the object which is then heated, sometimes in oil, vaporizing most of the mercury. The technique is dangerous since mercury is highly toxic, especially in its vapor phase. Mercury silvering can be detected through a variety of methods. The technique was also used in Asia, for example tokin plating in Edo-period Japan. == See also == Mercury glass, internally silvered decorative glass products named for their resemblance to mercury Liquid-mirror telescope, may use a layer of reflective mercury == References ==


id: merox-20260505-0
file: data/en.wikipedia.org/wiki/Merox-0.md
category: reference
title: Merox
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Merox
date_saved: 2026-05-05T10:49:02.530750+00:00
instance: kb-cron
parent: merox-20260505-0
summary:
Merox is an acronym for mercaptan oxidation. It is a proprietary catalytic chemical process developed by UOP used in oil refineries and natural gas processing plants to remove mercaptans from LPG, propane, butanes, light naphthas, kerosene, and jet fuel by converting them to liquid hydrocarbon disulfides. The Merox process requires an alkaline environment which, in some process versions, is provided by an aqueous solution of sodium hydroxide (NaOH), a strong base, commonly referred to as caustic. In other versions of the process, the alkalinity is provided by ammonia, which is a weak base. The catalyst in some versions of the process is a water-soluble liquid. In other versions, the catalyst is impregnated into charcoal granules. Processes within oil refineries or natural gas processing plants that remove mercaptans and/or hydrogen sulfide (H2S) are commonly referred to as sweetening processes because they result in products which no longer have the sour, foul odors of mercaptans and hydrogen sulfide. The liquid hydrocarbon disulfides may remain in the sweetened products. These may be used as part of the refinery or natural gas processing plant fuel, or they may be processed further. When dealing with kerosene, the Merox process is usually more economical than using


id: merox-20260505-1
file: data/en.wikipedia.org/wiki/Merox-1.md
category: reference
title: Merox
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Merox
date_saved: 2026-05-05T10:49:02.530750+00:00
instance: kb-cron
parent: merox-20260505-0
summary:
=== Flow diagram === The flow diagram below depicts the equipment and the flow paths involved in the process. The LPG (or light naphtha) feedstock enters the prewash vessel and flows upward through a batch of caustic which removes any H2S that may be present in the feedstock. The coalescer at the top of the prewash vessel prevents caustic from being entrained and carried out of the vessel. The feedstock then enters the mercaptan extractor and flows upward through the contact trays where the LPG intimately contacts the downflowing Merox caustic that extracts the mercaptans from the LPG. The sweetened LPG exits the tower and flows through: a caustic settler vessel to remove any entrained caustic, a water wash vessel to further remove any residual entrained caustic and a vessel containing a bed of rock salt to remove any entrained water. The dry sweetened LPG exits the Merox unit. The caustic solution leaving the bottom of the mercaptan extractor ("rich" Merox caustic) flows through a control valve which maintains the extractor pressure needed to keep the LPG liquified. It is then injected with UOP's proprietary liquid catalyst (on an as needed basis), flows through a steam-heated heat exchanger and is


id: metal-vapor-synthesis-20260505-0
file: data/en.wikipedia.org/wiki/Metal_vapor_synthesis-0.md
category: reference
title: Metal vapor synthesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Metal_vapor_synthesis
date_saved: 2026-05-05T10:49:03.899826+00:00
instance: kb-cron
parent: metal-vapor-synthesis-20260505-0
summary:
In chemistry, metal vapor synthesis (MVS) is a method for preparing metal complexes by combining freshly produced metal atoms or small particles with ligands. In contrast to the high reactivity of such freshly produced metal atoms, bulk metals typically are unreactive toward neutral ligands. The method has been used to prepare compounds that cannot be prepared by traditional synthetic methods, e.g. Ti(η6-toluene)2. The technique relies on a reactor that evaporates the metal, allowing the vapor to impinge on a cold reactor wall that is coated with the organic ligand. The metal evaporates upon being heated resistively or irradiated with an electron beam. The apparatus operates under high vacuum. In a common implementation, the metal vapor and the organic ligand are co-condensed at liquid nitrogen temperatures. In several case where compounds are prepared by MVS, related preparations employ conventional routes. Thus, tris(butadiene)molybdenum was first prepared by co-condensation of butadiene and Mo vapor, but yields are higher for the reduction of molybdenum(V) chloride in the presence of the diene. == References ==


id: metal-induced-crystallization-20260505-0
file: data/en.wikipedia.org/wiki/Metal-induced_crystallization-0.md
category: reference
title: Metal-induced crystallization
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Metal-induced_crystallization
date_saved: 2026-05-05T10:49:05.059664+00:00
instance: kb-cron
parent: metal-induced-crystallization-20260505-0
summary:
Combined with certain metallic species, amorphous films can crystallize in a process known as metal-induced crystallization (MIC). The effect was discovered in 1969, when amorphous germanium (a-Ge) films crystallized at surprisingly low temperatures when in contact with aluminum, silver, copper, or tin. The effect was also verified in amorphous silicon (a-Si) films, as well as in amorphous carbon and various metal-oxide films. Likewise, the MIC evolved from simple temperature-driven annealing approaches to others involving lasers or microwave radiation, for example. A very common variant of the MIC procedure is the metal-induced lateral crystallization (MILC). In this case, the metal is deposited (onto the top or at the bottom) of some selected areas of the desired amorphous film. Upon annealing, crystallization starts from the portion of the amorphous film that is in contact with the metal species, and the MIC proceeds laterally. == References ==


id: methanation-20260505-0
file: data/en.wikipedia.org/wiki/Methanation-0.md
category: reference
title: Methanation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Methanation
date_saved: 2026-05-05T10:49:06.202076+00:00
instance: kb-cron
parent: methanation-20260505-0
summary:
Methanation is the conversion of carbon monoxide and carbon dioxide (COx) to methane (CH4) through hydrogenation. The methanation reactions of COx were first discovered by Sabatier and Senderens in 1902. COx methanation has many practical applications. It is a means of carbon oxide removal from process gases and is also being discussed as an alternative to PROX in fuel processors for mobile fuel cell applications. Methanation as a means of producing synthetic natural gas has been considered since the 1970s. More recently it has been considered as a way to store energy produced from solar or wind power using power-to-gas systems in conjunction with existing natural gas storage. == Chemical reactions == The following reactions describe the methanation of carbon monoxide and carbon dioxide respectively: CO + 3 H 2 ⟶ CH 4 + H 2 O {\displaystyle {\ce {CO + 3H2 -> CH4 + H2O}}} △H = -206 kJ/mol CO 2 + 4 H 2 ⟶ CH 4 + 2 H 2 O {\displaystyle {\ce {CO2 + 4H2 -> CH4 + 2 H2O}}} △H = -164 kJ/mol The methanation reactions are highly exothermic and release significant amounts of heat during reaction completion. There is disagreement on whether the CO2


id: micro-compounding-20260505-0
file: data/en.wikipedia.org/wiki/Micro-compounding-0.md
category: reference
title: Micro-compounding
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Micro-compounding
date_saved: 2026-05-05T10:49:07.395983+00:00
instance: kb-cron
parent: micro-compounding-20260505-0
summary:
Micro-compounding is the mixing or processing of polymer formulations in the melt on a small scale, typically milliliters. It is popular for research and development because it gives faster, more reliable results with smaller samples and less cost. Its applications include pharmaceutical, biomedical, and nutritional areas. == Design == Micro-compounding is typically performed with a tabletop, twin screw micro-compounder, or micro-extruder with a working volume of 5 or 15 milliliters. With such small volumes, it is difficult to have sufficient mixing in a continuous extruder. Therefore, micro-compounders typically have a batch mode (recirculation) and a conical shape. The L/D of a continuous twin screw extruder is mimicked in a batch micro-compounder by the recirculation mixing time, which is controlled by a manual valve. With this valve, the recirculation can be interrupted to unload the formulation in either a strand or an injection moulder, a film device or a fiber line. Typical recirculation times are one to three minutes, depending on the ease of dispersive and distributive mixing of the formulation. == Benefits == Micro-compounding can now produce films, fibers, and test samples (rods, rings, tablets) from mixtures as small as 5 ml in less than ten minutes. The small footprint


id: micro-pulling-down-20260505-0
file: data/en.wikipedia.org/wiki/Micro-pulling-down-0.md
category: reference
title: Micro-pulling-down
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Micro-pulling-down
date_saved: 2026-05-05T10:49:08.623875+00:00
instance: kb-cron
parent: micro-pulling-down-20260505-0
summary:
The micro-pulling-down (μ-PD) method is a crystal growth technique based on continuous transport of the melted substance through micro-channel(s) made in a crucible bottom. Continuous solidification of the melt is progressed on a liquid/solid interface positioned under the crucible. In a steady state, both the melt and the crystal are pulled-down with a constant (but generally different) velocity. Many different types of crystal are grown by this technique, including Y3Al5O12, Si, Si-Ge, LiNbO3, α-Al2O3, Y2O3, Sc2O3, LiF, CaF2, BaF2, etc. == Crystal growth routine == Standard routine procedure used in the growth of most of μ-PD crystals is well developed. The general stages of the growths include: Charging of the crucible with starting materials (mixture of powders) Heating of the crucible until starting materials in the crucible are completely melted Upward displacement of the seed until its contact with the meniscus or crucible Formation of the meniscus and partial melting of the seed top Correction of the shape of the meniscus through appropriate adjustment of crucible temperature and position of the seed crystal Crystal growth through pulling of the seed in downward direction Separation of the as grown crystal from the meniscus Cooling of the system (including the crystal and


id: molecular-laser-isotope-separation-20260505-0
file: data/en.wikipedia.org/wiki/Molecular_laser_isotope_separation-0.md
category: reference
title: Molecular laser isotope separation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Molecular_laser_isotope_separation
date_saved: 2026-05-05T10:49:09.777690+00:00
instance: kb-cron
parent: molecular-laser-isotope-separation-20260505-0
summary:
Molecular laser isotope separation (MLIS) is a method of isotope separation, where specially tuned lasers are used to separate isotopes of uranium using selective ionization of hyperfine transitions of uranium hexafluoride molecules. It is similar to AVLIS. Its main advantage over AVLIS is low energy consumption and use of uranium hexafluoride instead of vaporized uranium. MLIS was conceived in 1971 at the Los Alamos National Laboratory. MLIS operates in cascade setup, like the gaseous diffusion process. Instead of vaporized uranium as in AVLIS the working medium of the MLIS is uranium hexafluoride which requires a much lower temperature to vaporize. The UF6 gas is mixed with a suitable carrier gas (a noble gas including some hydrogen) which allows the molecules to remain in the gaseous phase after being cooled by expansion through a supersonic de Laval nozzle. A scavenger gas (e.g. methane) is also included in the mixture to bind with the fluorine atoms after they are dissociated from the UF6 and inhibit their recombination with the enriched UF5 product. In the first stage, the expanded and cooled stream of UF6 is irradiated with an infrared laser operating at the wavelength of 16 μm. The mix is then irradiated with


id: molecular-layer-deposition-20260505-0
file: data/en.wikipedia.org/wiki/Molecular_layer_deposition-0.md
category: reference
title: Molecular layer deposition
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Molecular_layer_deposition
date_saved: 2026-05-05T10:49:10.956175+00:00
instance: kb-cron
parent: molecular-layer-deposition-20260505-0
summary:
Molecular layer deposition (MLD) is a vapour phase thin film deposition technique based on self-limiting surface reactions carried out in a sequential manner. Essentially, MLD resembles the well established technique of atomic layer deposition (ALD) but, whereas ALD is limited to exclusively inorganic coatings, the precursor chemistry in MLD can use small, bifunctional organic molecules as well. This enables, as well as the growth of organic layers in a process similar to polymerization, the linking of both types of building blocks together in a controlled way to build up organic-inorganic hybrid materials. Even though MLD is a known technique in the thin film deposition sector, due to its relative youth it is not as explored as its inorganic counterpart, ALD, and a wide sector development is expected in the upcoming years. == History == Molecular layer deposition is a sister technique of atomic layer deposition. While the history of atomic layer deposition dates back to the 1970s, thanks to the independent work of Valentin Borisovich Aleskovskii. and Tuomo Suntola, the first MLD experiments with organic molecules were not published until 1991, when an article from Tetsuzo Yoshimura and co-workers appeared regarding the synthesis of polyimides using amines and anhydrides as


id: molecular-layer-deposition-20260505-1
file: data/en.wikipedia.org/wiki/Molecular_layer_deposition-1.md
category: reference
title: Molecular layer deposition
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Molecular_layer_deposition
date_saved: 2026-05-05T10:49:10.956175+00:00
instance: kb-cron
parent: molecular-layer-deposition-20260505-0
summary:
== Process chemistry and surface reactions == Precursor chemistry plays a key role in MLD. The chemical properties of the precursor molecules drive the composition, structure and stability of the deposited hybrid material. To reach the saturation stage in a short time and ensure a reasonable deposition rate, precursors must chemisorb on the surface, react rapidly with the surface active groups and react with each other. The desired MLD reactions should have a large negative ∆G value. Organic compounds are employed as precursors for MLD. For their effective use, the precursor should have sufficient vapor pressure and thermal stability to be transported in the gas phase to the reaction zone without decomposing. Volatility is influenced by the molecular weight and intermolecular interactions. One of the challenges in MLD is to find an organic precursor that has sufficient vapor pressure, reactivity and thermal stability. Most organic precursors have low volatility, and heating is necessary to ensure the sufficient supply of vapor reaching the substrate. The backbone of the organic precursors can be flexible i.e., aliphatic, or rigid i.e., aromatics employed with the functional groups. The organic precursors usually are homo or heterobifunctional molecules with -OH, -COOH, -NH2, -CONH2, -CHO, -COCl, -SH,


id: molecular-layer-deposition-20260505-2
file: data/en.wikipedia.org/wiki/Molecular_layer_deposition-2.md
category: reference
title: Molecular layer deposition
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Molecular_layer_deposition
date_saved: 2026-05-05T10:49:10.956175+00:00
instance: kb-cron
parent: molecular-layer-deposition-20260505-0
summary:
Molecule tilting: organic molecules with long chains are prone to not remaining completely perpendicular to the surface, lowering the number of surface sites. Bidentate ligands: when a reacting molecule has two functional groups, it may bend and react with two surface sites instead of remaining straight on the surface. This has been shown, for instance, for titanicones grown with ethylene glycol and glycerol. Because glycerol has an additional hydroxyl group compared to ethylene glycol and is able to provide an extra reactive hydroxyl group in the case of a double reaction of the terminal hydroxyl groups with the surface. Steric hindrance: organic precursors are often bulky, and can cover several surface groups when attached to the surface. Long pulsing times: organic precursors can have very low vapour pressures, and very long pulsing times may be necessary in order to achieve saturation. In addition, long purging times are usually needed to remove all unreacted molecules from the chamber afterward. Low temperatures: to increase the precursor vapor pressure, one might think of increasing its temperature. Nevertheless, organic precursors are usually very thermally fragile, and a temperature increase may induce decomposition. Gas-phase: many organic reactions are normally carried out in the liquid phase,


id: molecular-layer-deposition-20260505-3
file: data/en.wikipedia.org/wiki/Molecular_layer_deposition-3.md
category: reference
title: Molecular layer deposition
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Molecular_layer_deposition
date_saved: 2026-05-05T10:49:10.956175+00:00
instance: kb-cron
parent: molecular-layer-deposition-20260505-0
summary:
==== Gaseous precursors ==== ALD/MLD are both gas phase processes. Hence, precursors are required to be introduced into the reaction zones in their gaseous form. A precursor already existing in a gaseous physical state would make its transport to the reactor very straightforward and hassle free. For example, there will be no need of heating the precursor thereby reducing the risk of condensation. However, precursors are seldom available in gaseous state. On the other hand, some ALD co-reactants are available in gaseous form. Examples include H2S used for sulphide films; NH3 used for nitride films; plasmas of O2 and O3 to produce oxides. The most common and straight forward way of regulating the supply of these co-reactants to the reactor is using a mass flow controller attached between the source and the reactor. They can also be diluted with an inert gas to control their partial pressure. == Film characterisation == Several characterisation techniques have evolved over time as the demand for creating ALD/MLD films for different applications has increased. This includes lab-based characterisation and efficient synchrotron-based x-ray techniques. === Lab-based characterisation === Since they both follow a similar protocol, almost all characterisation applicable to ALD generally applies to MLD


id: molecular-layer-deposition-20260505-4
file: data/en.wikipedia.org/wiki/Molecular_layer_deposition-4.md
category: reference
title: Molecular layer deposition
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Molecular_layer_deposition
date_saved: 2026-05-05T10:49:10.956175+00:00
instance: kb-cron
parent: molecular-layer-deposition-20260505-0
summary:
==== High-k ==== Novel organic thin-film transistors require a high-performance dielectric layer, which should be thin and possess a high k-value. MLD makes tuning the high-k and dielectric strength possible by altering the amount and the ratio of the organic and inorganic components. Moreover, the usage of MLD allows to achieve better mechanical properties in terms of flexibility. Various hybrid dielectrics have already been developed: zincone hybrids from zirconium tert-butoxide (ZTB) and ethylene glycol (EG); Al2O3 based hybrids such as self-assembled MLD-deposited octenyltrichlorosilane (OTS) layers and Al2O3 linkers. Additionally, dielectric Ti-based hybrid from TiCl4 and fumaric acid proved its applicability in charge memory capacitors. === MLD for porous materials === MLD has high potential for the deposition of porous hybrid organic-inorganic and purely organic films, such as Metal-Organic Frameworks (MOFs) and Covalent-Organic Frameworks (COFs). Thanks to the defined pore structure and chemical tunability, thin films of these novel materials are expected to be incorporated in the next generation of gas sensors and low-k dielectrics. Conventionally, thin films of MOFs and COFs are grown via solvent-based routes, which are detrimental in a cleanroom environment and can cause corrosion of the pre-existing circuitry. As a cleanroom-compatible technique, MLD presents an attractive alternative,


id: molecular-layer-deposition-20260505-5
file: data/en.wikipedia.org/wiki/Molecular_layer_deposition-5.md
category: reference
title: Molecular layer deposition
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Molecular_layer_deposition
date_saved: 2026-05-05T10:49:10.956175+00:00
instance: kb-cron
parent: molecular-layer-deposition-20260505-0
summary:
==== Bioactive and biocompatible surfaces ==== MLD can also be applied to design of bioactive and biocompatible surfaces for targeted cell and tissue responses. Bioactive materials involve materials for regenerative medicine, tissue engineering (tissue scaffolds), biosensors etc. The important factors that can affect the cell-surface interaction, as well as the immune response of the system are surface chemistry (e.g. functional groups, surface charge and wettability) and surface topography. Understanding these properties is crucial in order to control the attachment and proliferation of the cell, and resultant bioactivity of the surfaces. Furthermore, the choice of organic building blocks and a type of biomolecules (e.g. proteins, peptides or polysaccharides) during the formation of bioactive surfaces is a key factor for cellular response of the surface. MLD allows for the building of bioactive, precise structures by combining such organic molecules with inorganic biocompatible elements like titanium. The use of MLD for biomedical applications is not widely studied and is a promising field of research. This method enables surface modification and thus, can functionalize a surface. A recent study published in 2017 used MLD to create bioactive scaffolds by combining titanium clusters with amino acids such as glycine, L-aspartic acid and L-arginine as organic


id: mond-process-20260505-0
file: data/en.wikipedia.org/wiki/Mond_process-0.md
category: reference
title: Mond process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Mond_process
date_saved: 2026-05-05T10:49:12.151423+00:00
instance: kb-cron
parent: mond-process-20260505-0
summary:
The Mond process, sometimes known as the carbonyl process, is a technique created by Ludwig Mond in 1890, to extract and purify nickel. The process was used commercially before the end of the 19th century, and particularly by the International Nickel Company in the Sudbury Basin. This process converts nickel oxides into nickel metal with very high purity being attainable in just a single step. == Synopsis == This process involves the fact that carbon monoxide combines with nickel readily and reversibly to give nickel carbonyl. Few other elements other than nickel, iron, and cobalt form carbonyl compounds under the mild conditions used in the process. This process has three steps: 1. Metal Feed (consisting of primarily Nickel oxide) reacts with hydrogen at 200 °C to give nickel. Other impurities including iron and cobalt are also reduced. NiO(s) + H2(g) → Ni(s) + H2O(g) 2. The impure nickel reacts with carbon monoxide at 50–60 °C to form the gas nickel carbonyl, leaving the impurities as solids. Ni(s) + 4 CO(g) → Ni(CO)4(g) 3. The mixture of nickel carbonyl and carbon monoxide is heated to 220–250 °C, resulting in decomposition back to nickel and carbon monoxide: Ni(CO)4(g) → Ni(s) + 4


id: monsanto-process-20260505-0
file: data/en.wikipedia.org/wiki/Monsanto_process-0.md
category: reference
title: Monsanto process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Monsanto_process
date_saved: 2026-05-05T10:49:13.296370+00:00
instance: kb-cron
parent: monsanto-process-20260505-0
summary:
The Monsanto process is an industrial method for the manufacture of acetic acid by catalytic carbonylation of methanol. The Monsanto process has largely been supplanted by the Cativa process, a similar iridium-based process developed by BP Chemicals Ltd, which is more economical and environmentally friendly. This process operates at a pressure of 30–60 atm and a temperature of 150–200 °C and gives a selectivity greater than 99%. It was developed in 1960 by the German chemical company BASF and improved by the Monsanto Company in 1966, which introduced a new catalyst system. == Catalytic cycle == The catalytically active species is the anion cis-[Rh(CO)2I2]− (top of scheme). The first organometallic step is the oxidative addition of methyl iodide to cis-[Rh(CO)2I2]− to form the hexacoordinate species [(CH3)Rh(CO)2I3]−. This anion rapidly transforms, via the migration of a methyl group to an adjacent carbonyl ligand, affording the pentacoordinate acetyl complex [(CH3CO)Rh(CO)I3]−. This five-coordinate complex then reacts with carbon monoxide to form the six-coordinate dicarbonyl complex, which undergoes reductive elimination to release acetyl iodide (CH3C(O)I). The catalytic cycle involves two non-organometallic steps: conversion of methanol to methyl iodide and the hydrolysis of the acetyl iodide to acetic acid and hydrogen iodide. The reaction has


id: natural-gas-processing-20260505-0
file: data/en.wikipedia.org/wiki/Natural-gas_processing-0.md
category: reference
title: Natural-gas processing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Natural-gas_processing
date_saved: 2026-05-05T10:49:14.463304+00:00
instance: kb-cron
parent: natural-gas-processing-20260505-0
summary:
Natural-gas processing is a range of industrial processes designed to purify raw natural gas by removing contaminants such as solids, water, carbon dioxide (CO2), hydrogen sulfide (H2S), mercury and higher molecular mass hydrocarbons (condensate) to produce pipeline quality dry natural gas for pipeline distribution and final use. Some of the substances which contaminate natural gas have economic value and are further processed or sold. Hydrocarbons that are liquid at ambient conditions: temperature and pressure (i.e., pentane and heavier) are called natural-gas condensate (sometimes also called natural gasoline or simply condensate). Raw natural gas comes primarily from three types of wells: crude oil wells, gas wells, and condensate wells. Crude oil and natural gas are often found together in the same reservoir. Natural gas produced in wells with crude oil is generally classified as associated-dissolved gas as the gas had been associated with or dissolved in crude oil. Natural gas production not associated with crude oil is classified as “non-associated.” In 2009, 89 percent of U.S. wellhead production of natural gas was non-associated. Non-associated gas wells producing a dry gas in terms of condensate and water can send the dry gas directly to a pipeline or gas plant without undergoing any


id: natural-gas-processing-20260505-1
file: data/en.wikipedia.org/wiki/Natural-gas_processing-1.md
category: reference
title: Natural-gas processing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Natural-gas_processing
date_saved: 2026-05-05T10:49:14.463304+00:00
instance: kb-cron
parent: natural-gas-processing-20260505-0
summary:
Be free of particulate solids and liquid water to prevent erosion, corrosion or other damage to the pipeline. Be dehydrated of water vapor sufficiently to prevent the formation of methane hydrates within the gas processing plant or subsequently within the sales gas transmission pipeline. A typical water content specification in the U.S. is that gas must contain no more than seven pounds of water per million standard cubic feet of gas. In the UK this is defined as <-10 °C @ 85barg for entry into the NTS. Contain no more than trace amounts of components such as hydrogen sulfide, carbon dioxide, mercaptans, and nitrogen. The most common specification for hydrogen sulfide content is 0.25 grain H2S per 100 cubic feet of gas, or approximately 4 ppm. Specifications for CO2 typically limit the content to no more than two or three percent. In the UK hydrogen sulfide is specified ≤5 mg/m3 and total sulfur as ≤50 mg/m3, carbon dioxide as ≤2.0% (molar), and nitrogen as ≤5.0% (molar) for entry into the NTS. Maintain mercury at less than detectable limits (approximately 0.001 ppb by volume) primarily to avoid damaging equipment in the gas processing plant or the pipeline transmission system from mercury


id: natural-gas-processing-20260505-2
file: data/en.wikipedia.org/wiki/Natural-gas_processing-2.md
category: reference
title: Natural-gas processing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Natural-gas_processing
date_saved: 2026-05-05T10:49:14.463304+00:00
instance: kb-cron
parent: natural-gas-processing-20260505-0
summary:
Condensed liquid passes through a Joule-Thomson valve reducing the pressure to 20 bar and enters the demethanizer as the lower feed at -44.7 °C. Some of the vapour is routed through a turbo-expander and enters the demethanizer as the upper feed at -64 °C. The remaining vapor is chilled by the demethanizer overhead product and Joule-Thomson cooling (through a valve) and enters the column as reflux at -96 °C. The overhead product is mainly methane at 20 bar and -98 °C. This is heated and compressed to yield a sales gas at 20 bar and 40 °C. The bottom product is NGL at 20 barg which is fed to the deethanizer. The overhead product from the deethanizer is ethane and the bottoms are fed to the depropanizer. The overhead product from the depropanizer is propane and the bottoms are fed to the debutanizer. The overhead product from the debutanizer is a mixture of normal and iso-butane, and the bottoms product is a C5+ gasoline mixture. The operating conditions of the vessels in the NGL fractionation train are typically as follows. A typical composition of the feed and product is as follows. === Sweetening Units === The recovered streams of propane,


id: newbery-vautin-chlorination-process-20260505-0
file: data/en.wikipedia.org/wiki/Newbery–Vautin_chlorination_process-0.md
category: reference
title: Newbery–Vautin chlorination process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Newbery–Vautin_chlorination_process
date_saved: 2026-05-05T10:49:15.658889+00:00
instance: kb-cron
parent: newbery-vautin-chlorination-process-20260505-0
summary:
The Newbery–Vautin chlorination process is a method for extracting gold from its ore through the use of chlorination. This process was jointly developed by James Cosmo Newbery and Claude Theodore James Vautin. == Chlorination process == === History === A process for extracting gold from gold ores containing pyrite using chlorine gas was introduced by Karl Friedrich Plattner (1800–1858), around 1848. James Newbery and Claude Vautin began work on chlorination, at the United Pyrites Gold Extracting Co. in Bendigo, in 1878. They were awarded Victorian Patent No. 4484, in 1886, for their Newbery–Vautin chlorination process, which was faster than earlier chlorination processes. === Process description === Roasted gold-bearing pyrite concentrates and water were combined in a barrel, to which calcium chloride and sulphuric acid were added. The barrel was then made airtight. Compressed air was used to raise the internal pressure to four atmospheres, and the barrel was set in rotation. The sulphuric acid and calcium chloride reacted to form chlorine gas. The gold contained in the concentrate reacted with the chlorine to form gold chloride, which is a salt soluble in water. Once the extraction had occurred—after around four hours—the liquid containing the gold chloride was separated from the


id: nitrophosphate-process-20260505-0
file: data/en.wikipedia.org/wiki/Nitrophosphate_process-0.md
category: reference
title: Nitrophosphate process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Nitrophosphate_process
date_saved: 2026-05-05T10:49:16.886778+00:00
instance: kb-cron
parent: nitrophosphate-process-20260505-0
summary:
The nitrophosphate process (also known as the Odda process) is a method for the industrial production of nitrogen fertilizers invented by Erling Johnson in Odda Municipality, Norway. around 1927. The process involves acidifying phosphate rock with dilute nitric acid to produce a mixture of phosphoric acid and calcium nitrate. Ca 5 ( PO 4 ) 3 OH + 10 HNO 3 ⟶ 3 H 3 PO 4 + 5 Ca ( NO 3 ) 2 + H 2 O {\displaystyle {\ce {Ca5(PO4)3OH + 10 HNO3 -> 3 H3PO4 + 5 Ca(NO3)2 + H2O}}} The mixture is cooled to below 0 °C, where the calcium nitrate crystallizes and can be separated from the phosphoric acid. 2 H 3 PO 4 + 3 Ca ( NO 3 ) 2 + 12 H 2 O ⟶ 2 H 3 PO 4 + 3 Ca ( NO 3 ) 2 ⋅ 4 H 2 O {\displaystyle {\ce {2 H3PO4 + 3 Ca(NO3)2 + 12 H2O -> 2 H3PO4 + 3 Ca(NO3)2.4H2O}}} The resulting calcium nitrate produces nitrogen fertilizer. The filtrate is composed mainly of phosphoric acid with some nitric acid and traces of calcium nitrate, and this is neutralized with ammonia to produce a


id: oil-refinery-20260505-0
file: data/en.wikipedia.org/wiki/Oil_refinery-0.md
category: reference
title: Oil refinery
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Oil_refinery
date_saved: 2026-05-05T10:49:18.084931+00:00
instance: kb-cron
parent: oil-refinery-20260505-0
summary:
An oil refinery or petroleum refinery is an industrial process plant where petroleum (crude oil) is transformed and refined into products such as gasoline (petrol), diesel fuel, asphalt base, fuel oils, heating oil, kerosene, liquefied petroleum gas and petroleum naphtha. Petrochemical feedstock like ethylene and propylene can also be produced directly by cracking crude oil without the need of using refined products of crude oil such as naphtha. The crude oil feedstock has typically been processed by an oil production plant. There is usually an oil depot at or near an oil refinery for the storage of incoming crude oil feedstock as well as bulk liquid products. In 2020, the total capacity of global refineries for crude oil was about 101.2 million barrels per day. Oil refineries are typically large, sprawling industrial complexes with extensive piping running throughout, carrying streams of fluids between large chemical processing units, such as distillation columns. In many ways, oil refineries use many different technologies and can be thought of as types of chemical plants. Since December 2008, the world's largest oil refinery has been the Jamnagar Refinery owned by Reliance Industries, located in Gujarat, India, with a processing capacity of 1.24 million barrels (197,000


id: oil-refinery-20260505-1
file: data/en.wikipedia.org/wiki/Oil_refinery-1.md
category: reference
title: Oil refinery
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Oil_refinery
date_saved: 2026-05-05T10:49:18.084931+00:00
instance: kb-cron
parent: oil-refinery-20260505-0
summary:
== History == The Chinese were among the first civilizations to refine oil. As early as the first century, the Chinese were refining crude oil for use as an energy source. Between 512 and 518, in the late Northern Wei dynasty, the Chinese geographer, writer and politician Li Daoyuan introduced the process of refining oil into various lubricants in his famous work Commentary on the Water Classic. Crude oil was often distilled by Persian chemists, with clear descriptions given in handbooks such as those of Muhammad ibn Zakarīya Rāzi (c. 865–925). The streets of Baghdad were paved with tar, derived from petroleum that became accessible from natural fields in the region. In the 9th century, oil fields were exploited in the area around modern Baku, Azerbaijan. These fields were described by the Arab geographer Abu al-Hasan 'Alī al-Mas'ūdī in the 10th century, and by Marco Polo in the 13th century, who described the output of those wells as hundreds of shiploads. Arab and Persian chemists also distilled crude oil in order to produce flammable products for military purposes. Through Islamic Spain, distillation became available in Western Europe by the 12th century. In the Northern Song dynasty (960–1127), a workshop called


id: oil-refinery-20260505-2
file: data/en.wikipedia.org/wiki/Oil_refinery-2.md
category: reference
title: Oil refinery
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Oil_refinery
date_saved: 2026-05-05T10:49:18.084931+00:00
instance: kb-cron
parent: oil-refinery-20260505-0
summary:
In the United States, for various complex economic and political reasons, the construction of new refineries came to a virtual stop in about the 1980s. However, many of the existing refineries in the United States have revamped many of their units and/or constructed add-on units in order to: increase their crude oil processing capacity, increase the octane rating of their product gasoline, lower the sulfur content of their diesel fuel and home heating fuels to comply with environmental regulations and comply with environmental air pollution and water pollution requirements. === United States === In the 19th century, refineries in the U.S. processed crude oil primarily to recover the kerosene. There was no market for the more volatile fraction, including gasoline, which was considered waste and was often dumped directly into the nearest river. The invention of the automobile shifted demand to gasoline and diesel, which remain the primary refined products today. Today, national and state legislation require refineries to meet stringent air and water cleanliness standards. In fact, oil companies in the U.S. perceive obtaining a permit to build a modern refinery to be so difficult and costly that no new refineries were built (though many have been expanded) in


id: oil-refinery-20260505-3
file: data/en.wikipedia.org/wiki/Oil_refinery-3.md
category: reference
title: Oil refinery
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Oil_refinery
date_saved: 2026-05-05T10:49:18.084931+00:00
instance: kb-cron
parent: oil-refinery-20260505-0
summary:
Petroleum products are materials derived from crude oil (petroleum) as it is processed in oil refineries. The majority of petroleum is converted to petroleum products, which includes several classes of fuels. Oil refineries also produce various intermediate products such as hydrogen, light hydrocarbons, reformate and pyrolysis gasoline. These are not usually transported but instead are blended or processed further on-site. Chemical plants are thus often adjacent to oil refineries or a number of further chemical processes are integrated into it. For example, light hydrocarbons are steam-cracked in an ethylene plant, and the produced ethylene is polymerized to produce polyethene. To ensure both proper separation and environmental protection, a very low sulfur content is necessary in all but the heaviest products. The crude sulfur contaminant is transformed to hydrogen sulfide via catalytic hydrodesulfurization and removed from the product stream via amine gas treating. Using the Claus process, hydrogen sulfide is afterward transformed to elementary sulfur to be sold to the chemical industry. The rather large heat energy freed by this process is directly used in the other parts of the refinery. Often an electrical power plant is combined into the whole refinery process to take up the excess heat. According to


id: oil-refinery-20260505-4
file: data/en.wikipedia.org/wiki/Oil_refinery-4.md
category: reference
title: Oil refinery
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Oil_refinery
date_saved: 2026-05-05T10:49:18.084931+00:00
instance: kb-cron
parent: oil-refinery-20260505-0
summary:
Desalter unit washes out salt, and other water-soluble contaminants, from the crude oil before it enters the atmospheric distillation unit. Pre-flash and/or pre-distillation which is found in most atmospheric crude oil units of more than 100,000 bpsd in capacity. Crude oil distillation unit distills the incoming crude oil into various fractions for further processing in other units. See continuous distillation. Vacuum distillation further distills the residue oil from the bottom of the crude oil distillation unit. The vacuum distillation is performed at a pressure well below atmospheric pressure. Naphtha hydrotreater unit uses hydrogen to desulfurize naphtha from atmospheric distillation. Naphtha must be desulfurized before sending it to a catalytic reformer unit. Catalytic reformer converts the desulfurized naphtha molecules into higher-octane molecules to produce reformate (reformer product). The reformate has higher content of aromatics and cyclic hydrocarbons which is a component of the end-product gasoline or petrol. An important byproduct of a reformer is hydrogen released during the catalyst reaction. The hydrogen is used either in the hydrotreaters or the hydrocracker. Distillate hydrotreater desulfurizes distillates (such as diesel) after atmospheric distillation. Uses hydrogen to desulfurize the naphtha fraction from the crude oil distillation or other units within the refinery. Distillate hydrotreaters


id: oil-refinery-20260505-5
file: data/en.wikipedia.org/wiki/Oil_refinery-5.md
category: reference
title: Oil refinery
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Oil_refinery
date_saved: 2026-05-05T10:49:18.084931+00:00
instance: kb-cron
parent: oil-refinery-20260505-0
summary:
== Crude oil distillation unit == The crude oil distillation unit (CDU) is the first processing unit in virtually all petroleum refineries. The CDU distills the incoming crude oil into various fractions of different boiling ranges, each of which is then processed further in the other refinery processing units. The CDU is often referred to as the atmospheric distillation unit because it operates at slightly above atmospheric pressure. Below is a schematic flow diagram of a typical crude oil distillation unit. The incoming crude oil is preheated by exchanging heat with some of the hot, distilled fractions and other streams. It is then desalted to remove inorganic salts (primarily sodium chloride). Following the desalter, the crude oil is further heated by exchanging heat with some of the hot, distilled fractions and other streams. It is then heated in a fuel-fired furnace (fired heater) to a temperature of about 398 °C and routed into the bottom of the distillation unit. The cooling and condensing of the distillation tower overhead is provided partially by exchanging heat with the incoming crude oil and partially by either an air-cooled or water-cooled condenser. Additional heat is removed from the distillation column by a pumparound system


id: oil-refinery-20260505-6
file: data/en.wikipedia.org/wiki/Oil_refinery-6.md
category: reference
title: Oil refinery
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Oil_refinery
date_saved: 2026-05-05T10:49:18.084931+00:00
instance: kb-cron
parent: oil-refinery-20260505-0
summary:
=== Background === Modern petroleum refining involves a complicated system of interrelated chemical reactions that produce a wide variety of petroleum-based products. Many of these reactions require precise temperature and pressure parameters. The equipment and monitoring required to ensure the proper progression of these processes is complex, and has evolved through the advancement of the scientific field of petroleum engineering. The wide array of high pressure and/or high temperature reactions, along with the necessary chemical additives or extracted contaminants, produces an astonishing number of potential health hazards to the oil refinery worker. Through the advancement of technical chemical and petroleum engineering, the vast majority of these processes are automated and enclosed, thus greatly reducing the potential health impact to workers. However, depending on the specific process in which a worker is engaged, as well as the particular method employed by the refinery in which he/she works, significant health hazards remain. Although occupational injuries in the United States were not routinely tracked and reported at the time, reports of the health impacts of working in an oil refinery can be found as early as the 1800s. For instance, an explosion in a Chicago refinery killed 20 workers in 1890. Since then,


id: oil-refinery-20260505-7
file: data/en.wikipedia.org/wiki/Oil_refinery-7.md
category: reference
title: Oil refinery
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Oil_refinery
date_saved: 2026-05-05T10:49:18.084931+00:00
instance: kb-cron
parent: oil-refinery-20260505-0
summary:
=== Hazard controls === The theory of hierarchy of controls can be applied to petroleum refineries and their efforts to ensure worker safety. Elimination and substitution are unlikely in petroleum refineries, as many of the raw materials, waste products, and finished products are hazardous in one form or another (e.g. flammable, carcinogenic). Examples of engineering controls include a fire detection/extinguishing system, pressure/chemical sensors to detect/predict loss of structural integrity, and adequate maintenance of piping to prevent hydrocarbon-induced corrosion (leading to structural failure). Other examples employed in petroleum refineries include the post-construction protection of steel components with vermiculite to improve heat/fire resistance. Compartmentalization can help to prevent a fire or other systems failure from spreading to affect other areas of the structure, and may help prevent dangerous reactions by keeping different chemicals separate from one another until they can be safely combined in the proper environment. Administrative controls include careful planning and oversight of the refinery cleaning, maintenance, and turnaround processes. These occur when many of the engineering controls are shut down or suppressed and may be especially dangerous to workers. Detailed coordination is necessary to ensure that maintenance of one part of the facility will not cause dangerous exposures to


id: oil-refinery-20260505-8
file: data/en.wikipedia.org/wiki/Oil_refinery-8.md
category: reference
title: Oil refinery
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Oil_refinery
date_saved: 2026-05-05T10:49:18.084931+00:00
instance: kb-cron
parent: oil-refinery-20260505-0
summary:
Corrosion of metallic components is a major factor of inefficiency in the refining process. Because it leads to equipment failure, it is a primary driver for the refinery maintenance schedule. Corrosion-related direct costs in the U.S. petroleum industry as of 1996 were estimated at US$3.7 billion. Corrosion occurs in various forms in the refining process, such as pitting corrosion from water droplets, embrittlement from hydrogen, and stress corrosion cracking from sulfide attack. From a materials standpoint, carbon steel is used for upwards of 80 percent of refinery components, which is beneficial due to its low cost. Carbon steel is resistant to the most common forms of corrosion, particularly from hydrocarbon impurities at temperatures below 205 °C, but other corrosive chemicals and environments prevent its use everywhere. Common replacement materials are low alloy steels containing chromium and molybdenum, with stainless steels containing more chromium dealing with more corrosive environments. More expensive materials commonly used are nickel, titanium, and copper alloys. These are primarily saved for the most problematic areas where extremely high temperatures and/or very corrosive chemicals are present. Corrosion is fought by a complex system of monitoring, preventative repairs, and careful use of materials. Monitoring methods include both offline checks


id: olin-raschig-process-20260505-0
file: data/en.wikipedia.org/wiki/Olin_Raschig_process-0.md
category: reference
title: Olin Raschig process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Olin_Raschig_process
date_saved: 2026-05-05T10:49:19.318530+00:00
instance: kb-cron
parent: olin-raschig-process-20260505-0
summary:
The Olin Raschig process is a chemical process for the production of hydrazine. The main steps in this process, patented by German chemist Friedrich Raschig in 1906 and one of three reactions named after him, are the formation of monochloramine from ammonia and hypochlorite, and the subsequent reaction of monochloramine with ammonia towards hydrazine. The process was further optimised and used by the Olin Corporation for the production of anhydrous hydrazine for aerospace applications. == Process == The commercially used Olin Raschig process consists of the following steps: First, sodium hypochlorite solution is mixed with a threefold excess of ammonia at 5 °C to give monochloramine. The primary reaction proceeds according to the idealised equation NaOCl + NH3 → NH2Cl + NaOH The monochloramine solution is then added to a 30-fold excess of ammonia at 130 °C and elevated pressure, causing a second reaction NH2Cl + NH3 → N2H4 + HCl The hydrochloric acid and sodium hydroxide byproducts undergo a secondary reaction to release the byproducts of water and sodium chloride. The overall reaction is thus NaOCl + 2NH3 → N2H4 + NaCl + H2O Excess ammonia and sodium chloride are removed by distillation, followed by azeotropic distillation with aniline


id: omega-process-20260505-0
file: data/en.wikipedia.org/wiki/OMEGA_process-0.md
category: reference
title: OMEGA process
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/OMEGA_process
date_saved: 2026-05-05T10:49:20.520442+00:00
instance: kb-cron
parent: omega-process-20260505-0
summary:
The OMEGA process ("Only MEG Advantage") is a chemical process discovered by the Shell Global Solutions company that is used to produce ethylene glycol from ethylene. This process comprises two steps, the controlled oxidation of ethylene to ethylene oxide, and the net hydrolysis of ethylene oxide to monoethylene glycol (MEG). The first chemical plant using the OMEGA process was started in South Korea. Subsequent OMEGA plants have been started in Saudi Arabia and Singapore. Shell claims that this process, compared to conventional ones, does not produce higher glycols, uses less steam and water, and generates less waste. == Ethylene oxidation == To produce ethylene oxide, ethylene is oxidized with dioxygen in the presence of a silver catalyst. Some ethylene is over-oxidized to carbon dioxide and water, which is wasteful; early processes only gave ~ 65% selectivity for ethylene oxide as a result. In the OMEGA process, over-oxidation is reduced by including ethyl chloride as a moderator. == Ethylene oxide hydrolysis == Conventionally, monoethylene glycol (HOC2H4OH) is produced by the controlled hydrolysis of ethylene oxide (C2H4O). The monoethylene glycol product is also able to react with ethylene oxide to give diethylene glycol, and so on; sequential reaction with ethylene oxide is


id: organosolv-20260505-0
file: data/en.wikipedia.org/wiki/Organosolv-0.md
category: reference
title: Organosolv
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Organosolv
date_saved: 2026-05-05T10:49:21.669767+00:00
instance: kb-cron
parent: organosolv-20260505-0
summary:
In industrial paper-making processes, organosolv is a pulping technique that uses an organic solvent to solubilise lignin and hemicellulose. It has been considered in the context of both pulp and paper manufacture and biorefining for subsequent conversion of cellulose to fuel ethanol. The process was invented by Theodor Kleinert in 1968 as an environmentally benign alternative to kraft pulping. Organosolv has several advantages when compared to other popular methods such as kraft or sulfite pulping. In particular, the ability to obtain relatively high quality lignin adds value to a process stream otherwise considered as waste. Organosolv solvents are easily recovered by distillation, leading to less water pollution and elimination of the odour usually associated with kraft pulping. == Solvents == Organosolv pulping involves contacting a lignocellulosic feedstock such as chipped wood with an aqueous organic solvent at temperatures ranging from 140 to 220 °C. This causes lignin to break down by hydrolytic cleavage of alpha aryl-ether links into fragments that are soluble in the solvent system. Solvents used include acetone, methanol, ethanol, butanol, ethylene glycol, formic acid, and acetic acid. The concentration of solvent in water ranges from 40 to 80%. Higher boiling solvents have the advantage of a lower


id: organosolv-20260505-1
file: data/en.wikipedia.org/wiki/Organosolv-1.md
category: reference
title: Organosolv
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Organosolv
date_saved: 2026-05-05T10:49:21.669767+00:00
instance: kb-cron
parent: organosolv-20260505-0
summary:
=== Chempolis process === Chempolis Ltd in Oulu, Finland has developed, since 1995, a process concept where any lignocellulosic fibrous biomass sources are delignified with formic acid (biosolvent) in a compact process. The so-called "formico" technology incorporates full biosolvent recovery by evaporation and distillation in order to have a closed-loop process with minimal water need and effluent discharge. The delignification selectively fractionates lignocellulose components into cellulosic fibre, hemicellulose and lignin. Part of the hemicelluloses react to furfural and acetic acid, which are recovered in the distillation process to high-grade commercial products. The clean cellulosic fibre is used in various high-end packaging and textile purposes (bleached easily with hydrogen peroxide), or hydrolysed into high-purity glucose readily converted into biochemicals, or the glucose is easily fermented to bioethanol. The dissolved hemicelluloses and lignin after delignification are concentrated in evaporation and separated to produce hemicellulose fraction suitable for fermentation into ethanol or conversion to biochemicals. The separated lignin is sulfur-free and used in high-end applications replacing fossil aromatics. === American Science and Technology (AST) process === American Science and Technology (AST) based out of Chicago, Illinois, USA, has developed a process which uses a patented second generation Organosolv process to convert any kind


id: osmotic-dehydration-20260505-0
file: data/en.wikipedia.org/wiki/Osmotic_dehydration-0.md
category: reference
title: Osmotic dehydration
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Osmotic_dehydration
date_saved: 2026-05-05T10:49:22.820567+00:00
instance: kb-cron
parent: osmotic-dehydration-20260505-0
summary:
Osmotic dehydration is an operation used for the partial removal of water from plant tissues by immersion in a hypertonic (osmotic) solution. Sugar or salt solutions are used to reduce the moisture content of foods before actual drying process. This technique is used to give the product quality improvement over conventional drying process. Mild heat treatment after osmotic dehydration favours colour and flavour retention resulting in the product having superior organoleptic characteristics. It also increases resistance to heat treatment, prevents enzymatic browning and inhibits activities of polyphenol oxidase. The process is economical. Osmotic dehydration depends on: Temperature of osmotic solution. Concentration of the osmotic solution. Osmotic agent used. Process duration. Geometry of food material. David Baszucki == Process == Water removal is based on the natural and non-destructive phenomenon of osmosis across cell membranes. The driving force for the diffusion of water from the tissue into the solution is provided by the higher osmotic pressure of the hyper-tonic solution. The diffusion of water is accompanied by the simultaneous counter diffusion of solutes from the osmotic solution into the tissue. Since the cell membrane responsible for osmotic transport is not perfectly selective, solutes present in the cells (organic acids, reducing sugars,


