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Selexol
Selexol is the trade name for an acid gas removal solvent that can separate acid gases such as hydrogen sulfide and carbon dioxide from feed gas streams such as synthesis gas produced by gasification of coal, coke, or heavy hydrocarbon oils. By doing so, the feed gas is made more suitable for combustion and/or further processing. It is made up of dimethyl ethers of polyethylene glycol.{{cite journal , author1=M. Ajhar , author2=M. Travesset , author3=S. Yüce , author4=T. Melin , title = Siloxane removal from landfill and digester gas – A technology overview , year = 2010 , journal = Bioresource Technology , volume = 101 , issue=9 , pages = 2913–2923 , doi= 10.1016/j.biortech.2009.12.018, pmid=20061140 Process description In the Selexol process (now licensed by UOP LLC), the Selexol solvent dissolves (absorbs) the acid gases from the feed gas at relatively high pressure, usually 300 to 2000 psia (2.07 to 13.8 MPa). The rich solvent containing the acid gases is then l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rectisol
Rectisol is the trade name for an acid gas removal process that uses methanol as a solvent to separate acid gases such as hydrogen sulfide and carbon dioxide from valuable feed gas streams. By doing so, the feed gas is made more suitable for combustion and/or further processing. Rectisol is used most often to treat synthesis gas (primarily hydrogen and carbon monoxide) produced by gasification of coal or heavy hydrocarbons, as the methanol solvent is well able to remove trace contaminants such as ammonia, mercury, and hydrogen cyanide usually found in these gases. As an acid gas and large component of valuable feed gas streams, CO2 is separated during the methanol solvent regeneration. Process description In thRectisol process(licensed by both Linde AG and Air Liquide's Lurgi division), cold methanol at approximately –40 °F (–40 °C) dissolves (absorbs) the acid gases from the feed gas at relatively high pressure, usually 400 to 1000 psia (2.76 to 6.89 MPa). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amine Gas Treating
Amine gas treating, also known as amine scrubbing, gas sweetening and acid gas removal, refers to a group of processes that use aqueous solutions of various alkylamines (commonly referred to simply as amines) to remove hydrogen sulfide (H2S) and carbon dioxide (CO2) from gases. It is a common unit process used in refineries, and is also used in petrochemical plants, natural gas processing plants and other industries. Processes within oil refineries or chemical processing plants that remove hydrogen sulfide are referred to as "sweetening" processes because the odor of the processed products is improved by the absence of hydrogen sulfide. An alternative to the use of amines involves membrane technology. However, membrane separation is less attractive due to the relatively high capital and operating costs as well as other technical factors. Many different amines are used in gas treating: * Diethanolamine (DEA) * Monoethanolamine (MEA) * Methyldiethanolamine (MDEA) * Diisopropa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sour Gas
Sour gas is natural gas or any other gas containing significant amounts of hydrogen sulfide (H2S). Natural gas is usually considered sour if there are more than 5.7 milligrams of H2S per cubic meter of natural gas, which is equivalent to approximately 4 ppm by volume under standard temperature and pressure.NaturalGas.org website page ''Processing Natural Gas'' However, this threshold varies by country, state, or even agency or application. For instance, the considers a sour gas pipeline one that carries gas over 100 ppm by volume of H2S. However, the |
Amine Treating
Amine gas treating, also known as amine scrubbing, gas sweetening and acid gas removal, refers to a group of processes that use aqueous solutions of various alkylamines (commonly referred to simply as amines) to remove hydrogen sulfide (H2S) and carbon dioxide (CO2) from gases. It is a common unit process used in refineries, and is also used in petrochemical plants, natural gas processing plants and other industries. Processes within oil refineries or chemical processing plants that remove hydrogen sulfide are referred to as "sweetening" processes because the odor of the processed products is improved by the absence of hydrogen sulfide. An alternative to the use of amines involves membrane technology. However, membrane separation is less attractive due to the relatively high capital and operating costs as well as other technical factors. Many different amines are used in gas treating: * Diethanolamine (DEA) * Monoethanolamine (MEA) * Methyldiethanolamine (MDEA) * Diisopropa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amine Gas Treater
Amine gas treating, also known as amine scrubbing, gas sweetening and acid gas removal, refers to a group of processes that use aqueous solutions of various alkylamines (commonly referred to simply as amines) to remove hydrogen sulfide (H2S) and carbon dioxide (CO2) from gases. It is a common unit process used in refineries, and is also used in petrochemical plants, natural gas processing plants and other industries. Processes within oil refineries or chemical processing plants that remove hydrogen sulfide are referred to as "sweetening" processes because the odor of the processed products is improved by the absence of hydrogen sulfide. An alternative to the use of amines involves membrane technology. However, membrane separation is less attractive due to the relatively high capital and operating costs as well as other technical factors. Many different amines are used in gas treating: * Diethanolamine (DEA) * Monoethanolamine (MEA) * Methyldiethanolamine (MDEA) * Diisopropa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyethylene Glycol
Polyethylene glycol (PEG; ) is a polyether compound derived from petroleum with many applications, from industrial manufacturing to medicine. PEG is also known as polyethylene oxide (PEO) or polyoxyethylene (POE), depending on its molecular weight. The structure of PEG is commonly expressed as H−(O−CH2−CH2)n−OH. Uses Medical uses * Pharmaceutical-grade PEG is used as an excipient in many pharmaceutical products, in oral, topical, and parenteral dosage forms. * PEG is the basis of a number of laxatives (as ''MiraLax''). Whole bowel irrigation with polyethylene glycol and added electrolytes is used for bowel preparation before surgery or colonoscopy. * PEG is used in medicines for treating disimpaction and maintenance therapy for children with constipation. * When attached to various protein medications or drug carriers, polyethylene glycol of suitable length slows down their clearance from the blood. * The possibility that PEG could be used to fuse axons is being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Claus Process
The Claus process is the most significant gas desulfurizing process, recovering elemental sulfur from gaseous hydrogen sulfide. First patented in 1883 by the chemist Carl Friedrich Claus, the Claus process has become the industry standard. The multi-step Claus process recovers sulfur from the gaseous hydrogen sulfide found in raw natural gas and from the by-product gases containing hydrogen sulfide derived from refining crude oil and other industrial processes. The by-product gases mainly originate from physical and chemical gas treatment units (Selexol, Rectisol, Purisol and amine scrubbers) in refineries, natural gas processing plants and gasification or synthesis gas plants. These by-product gases may also contain hydrogen cyanide, hydrocarbons, sulfur dioxide or ammonia. Gases with an H2S content of over 25% are suitable for the recovery of sulfur in straight-through Claus plants while alternate configurations such as a split-flow set up or feed and air preheating c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wet Sulfuric Acid Process
The wet sulfuric acid process (WSA process) is a gas desulfurization process. After Danish company Haldor Topsoe introduced this technology in 1987, it has been recognized as a process for recovering sulfur from various process gases in the form of commercial quality sulfuric acid (H2SO4) with the simultaneous production of high-pressure steam. The WSA process can be applied in all industries where the removal of sulfur is an issue. The wet catalysis process is used for processing sulfur-containing streams, such as: * H2S gas from e.g. amine gas treating unit * Off-gas from sour water stripper (SWS) gas *Off-gas from Rectisol *Spent acid from an alkylation unit *Claus process tail gas *Heavy residue or petcoke-fired utility boiler off-gas *Boiler flue gases from various processes SNOX flue gas desulfurization *Metallurgical process gas *Production of sulfuric acid The process ;The main reactions in the WSA process *Combustion: 2 H2S + 3 O2 2 H2O + 2 SO2 (-1036 kJ/mol) *Ox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid Gas
Acid gas is a particular typology of natural gas or any other gas mixture containing significant quantities of hydrogen sulfide (H2S), carbon dioxide (CO2), or similar acidic gases. A gas is determined to be acidic or not after it is mixed with water. The pH scale ranges from 0 to 14, anything above 7 is basic while anything below 7 is acidic. Water has a neutral pH of 7 so once a gas is mixed with water, if the resulting mixture has a pH of less than 7 that means it is an acidic gas. The term/s ''acid gas'' and ''sour gas'' are often incorrectly treated as synonyms. Strictly speaking, a sour gas is any gas that specifically contains hydrogen sulfide in significant amounts; an acid gas is any gas that contains significant amounts of acidic gases such as carbon dioxide (CO2) or hydrogen sulfide. Thus, carbon dioxide by itself is an acid gas but not a sour gas. Dangers of acid gas Once a process burns a gas containing an acidic mixture, that acid gas is released into the atmosphere. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid Gas Control
In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequence of database operations that satisfies the ACID properties (which can be perceived as a single logical operation on the data) is called a ''transaction''. For example, a transfer of funds from one bank account to another, even involving multiple changes such as debiting one account and crediting another, is a single transaction. In 1983, Andreas Reuter and Theo Härder coined the acronym ''ACID'', building on earlier work by Jim Gray who named atomicity, consistency, and durability, but not isolation, when characterizing the transaction concept. These four properties are the major guarantees of the transaction paradigm, which has influenced many aspects of development in database systems. According to Gray and Reuter, the IBM Informa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Processes
A chemical substance is a form of matter having constant chemical composition and characteristic properties. Some references add that chemical substance cannot be separated into its constituent elements by physical separation methods, i.e., without breaking chemical bonds. Chemical substances can be simple substances (substances consisting of a single chemical element), chemical compounds, or alloys. Chemical substances are often called 'pure' to set them apart from mixtures. A common example of a chemical substance is pure water; it has the same properties and the same ratio of hydrogen to oxygen whether it is isolated from a river or made in a laboratory. Other chemical substances commonly encountered in pure form are diamond (carbon), gold, table salt ( sodium chloride) and refined sugar ( sucrose). However, in practice, no substance is entirely pure, and chemical purity is specified according to the intended use of the chemical. Chemical substances exist as solids, liqu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrodesulfurization
Hydrodesulfurization (HDS) 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 () 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 result ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
