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Synthesis Gas
Syngas, or synthesis gas, is a mixture of hydrogen and carbon monoxide in various ratios. The gas often contains some carbon dioxide and methane. It is principally used for producing ammonia or methanol. Syngas is combustible and can be used as a fuel. Historically, it has been used as a replacement for gasoline when gasoline supply has been limited; for example, wood gas was used to power cars in Europe during WWII (in Germany alone, half a million cars were built or rebuilt to run on wood gas). Production Syngas is produced by steam reforming or partial oxidation of natural gas or liquid hydrocarbons, or coal gasification. : : : Steam reforming of methane is an endothermic reaction requiring 206 kJ/mol of energy: : In principle, but rarely in practice, biomass and related hydrocarbon feedstocks could be used to generate biogas and biochar in waste-to-energy gasification facilities. The gas generated (mostly methane and carbon dioxide) is sometimes described as ''syng ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter. Under standard conditions, hydrogen is a gas of diatomic molecules with the chemical formula, formula , called dihydrogen, or sometimes hydrogen gas, molecular hydrogen, or simply hydrogen. Dihydrogen is colorless, odorless, non-toxic, and highly combustible. Stars, including the Sun, mainly consist of hydrogen in a plasma state, while on Earth, hydrogen is found as the gas (dihydrogen) and in molecular forms, such as in water and organic compounds. The most common isotope of hydrogen (H) consists of one proton, one electron, and no neutrons. Hydrogen gas was first produced artificially in the 17th century by the reaction of acids with metals. Henry Cavendish, in 1766–1781, identified hydrogen gas as a distinct substance and discovere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endothermic Reaction
An endothermic process is a chemical or physical process that absorbs heat from its surroundings. In terms of thermodynamics, it is a thermodynamic process with an increase in the enthalpy (or internal energy ) of the system.Oxtoby, D. W; Gillis, H.P., Butler, L. J. (2015). '' Principle of Modern Chemistry'', Brooks Cole. p. 617. In an endothermic process, the heat that a system absorbs is thermal energy transfer into the system. Thus, an endothermic reaction generally leads to an increase in the temperature of the system and a decrease in that of the surroundings. The term was coined by 19th-century French chemist Marcellin Berthelot. The term ''endothermic'' comes from the Greek ἔνδον (''endon'') meaning 'within' and θερμ- (''therm'') meaning 'hot' or 'warm'. An endothermic process may be a chemical process, such as dissolving ammonium nitrate () in water (), or a physical process, such as the melting of ice cubes. The opposite of an endothermic process is an exoth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amine Scrubbing
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 "sour" 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) * Dii ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pressure Swing Adsorption
Pressure swing adsorption (PSA) is a technique used to separate some gas species from a mixture of gases (typically air) under pressure according to the species' molecular characteristics and affinity for an adsorbent material. It operates at near-ambient temperature and significantly differs from the cryogenic distillation commonly used to separate gases. Selective adsorbent materials (e.g., zeolites, (aka molecular sieves), activated carbon, etc.) are used as trapping material, preferentially adsorbing the target gas species at high pressure. The process then swings to low pressure to desorb the adsorbed gas. Process The pressure swing adsorption (PSA) process is based on the phenomenon that under high pressure, gases tend to be trapped onto solid surfaces, ''i.e.'' to be "adsorbed". The higher the pressure, the more gas is adsorbed. When the pressure is dropped, the gas is released, or desorbed. PSA can be used to separate gases in a mixture because different gases are adsor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water-gas Shift Reaction
Water gas is a kind of fuel gas, a mixture of carbon monoxide and hydrogen. It is produced by "alternately hot blowing a fuel layer okewith air and gasifying it with steam". The caloric yield of the fuel produced by this method is about 10% of the yield from a modern syngas plant. The coke needed to produce water gas also costs significantly more than the precursors for syngas (mainly methane from natural gas), making water gas technology an even less attractive business proposition. Production Synthesis gas is made by passing steam over a red-hot carbon fuel such as coke: : (Δ''H'' = +131 kJ/mol) The reaction is endothermic, so the fuel must be continually re-heated to maintain the reaction. To do this, an air stream, which alternates with the vapor stream, is introduced to combust some of the carbon: : (Δ''H'' = −393 kJ/mol) Theoretically, to make 6 L of water gas, 5 L of air is required. Alternatively, to prevent contamination with nitrogen, energy can be p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calorific Value
The heating value (or energy value or calorific value) of a substance, usually a fuel or food (see food energy), is the amount of heat released during the combustion of a specified amount of it. The ''calorific value'' is the total energy released as heat when a substance undergoes complete combustion with oxygen under standard conditions. The chemical reaction is typically a hydrocarbon or other organic molecule reacting with oxygen to form carbon dioxide and water and release heat. It may be expressed with the quantities: * energy/ mole of fuel * energy/mass of fuel * energy/volume of the fuel There are two kinds of enthalpy of combustion, called high(er) and low(er) heat(ing) value, depending on how much the products are allowed to cool and whether compounds like are allowed to condense. The high heat values are conventionally measured with a bomb calorimeter. Low heat values are calculated from high heat value test data. They may also be calculated as the difference betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exothermic Reaction
In thermochemistry, an exothermic reaction is a "reaction for which the overall standard enthalpy change Δ''H''⚬ is negative." Exothermic reactions usually release heat. The term is often confused with exergonic reaction, which IUPAC defines as "... a reaction for which the overall standard Gibbs energy change Δ''G''⚬ is negative." A strongly exothermic reaction will usually also be exergonic because Δ''H''⚬ makes a major contribution to Δ''G''⚬. Most of the spectacular chemical reactions that are demonstrated in classrooms are exothermic and exergonic. The opposite is an endothermic reaction, which usually takes up heat and is driven by an entropy increase in the system. Examples Examples are numerous: combustion, the thermite reaction, combining strong acids and bases, polymerizations. As an example in everyday life, hand warmers make use of the oxidation of iron to achieve an exothermic reaction: :4Fe + 3O2 → 2Fe2O3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Gas
Water gas is a kind of fuel gas, a mixture of carbon monoxide and hydrogen. It is produced by "alternately hot blowing a fuel layer okewith air and gasifying it with steam". The caloric yield of the fuel produced by this method is about 10% of the yield from a modern syngas plant. The coke needed to produce water gas also costs significantly more than the precursors for syngas (mainly methane from natural gas), making water gas technology an even less attractive business proposition. Production Synthesis gas is made by passing steam over a red-hot carbon fuel such as coke: : (Δ''H'' = +131 kJ/mol) The reaction is endothermic, so the fuel must be continually re-heated to maintain the reaction. To do this, an air stream, which alternates with the vapor stream, is introduced to combust some of the carbon: : (Δ''H'' = −393 kJ/mol) Theoretically, to make 6 L of water gas, 5 L of air is required. Alternatively, to prevent contamination with nitrogen, energy can be p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coke (fuel)
Coke is a grey, hard, and porous coal-based fuel with a high carbon content. It is made by heating coal or petroleum in the absence of air. Coke is an important industrial product, used mainly in iron ore smelting, but also as a fuel in stoves and forges. The unqualified term "coke" usually refers to the product derived from low-ash and low-sulphur bituminous coal by a process called coking. A similar product called petroleum coke, or pet coke, is obtained from crude petroleum in oil refinery, petroleum refineries. Coke may also be formed naturally by geology, geologic processes.B. Kwiecińska and H. I. Petersen (2004): "Graphite, semi-graphite, natural coke, and natural char classification — ICCP system". ''International Journal of Coal Geology'', volume 57, issue 2, pages 99-116. It is the residue of a destructive distillation process. Production Industrial coke furnaces The industrial production of coke from coal is called coking. The coal is baked in an airless k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Gas
Natural gas (also fossil gas, methane gas, and gas) is a naturally occurring compound of gaseous hydrocarbons, primarily methane (95%), small amounts of higher alkanes, and traces of carbon dioxide and nitrogen, hydrogen sulfide and helium. Methane is a colorless and odorless gas, and, after carbon dioxide, is the second-greatest greenhouse gas that contributes to global climate change. Because natural gas is odorless, a commercial odorizer, such as Methanethiol (mercaptan brand), that smells of hydrogen sulfide (rotten eggs) is added to the gas for the ready detection of gas leaks. Natural gas is a fossil fuel that is formed when layers of organic matter (primarily marine microorganisms) are thermally decomposed under oxygen-free conditions, subjected to intense heat and pressure underground over millions of years. The energy that the decayed organisms originally obtained from the sun via photosynthesis is stored as chemical energy within the molecules of methane and other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Energy Density
In physics, energy density is the quotient between the amount of energy stored in a given system or contained in a given region of space and the volume of the system or region considered. Often only the ''useful'' or extractable energy is measured. It is sometimes confused with stored energy per unit mass, which is called ''specific energy'' or . There are different types of energy stored, corresponding to a particular type of reaction. In order of the typical magnitude of the energy stored, examples of reactions are: Nuclear power, nuclear, Chemical energy, chemical (including Electrochemistry, electrochemical), electrical, pressure, Deformation (engineering), material deformation or in Electromagnetic field, electromagnetic fields. Nuclear reactions take place in stars and nuclear power plants, both of which derive energy from the binding energy of nuclei. Chemical reactions are used by organisms to derive energy from food and by automobiles from the combustion of gasoline. Liqu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waste-to-energy
Waste-to-energy (WtE) or energy-from-waste (EfW) refers to a series of processes designed to convert waste materials into usable forms of energy, typically electricity or heat. As a form of energy recovery, WtE plays a crucial role in both waste management and sustainable energy production by reducing the volume of waste in landfills and providing an alternative energy source. The most common method of WtE is direct combustion of waste to produce heat, which can then be used to generate electricity via steam turbines. This method is widely employed in many countries and offers a dual benefit: it disposes of waste while generating energy, making it an efficient process for both waste reduction and energy production. In addition to combustion, other WtE technologies focus on converting waste into fuel sources. For example, gasification and pyrolysis are processes that thermochemically decompose organic materials in the absence of oxygen to produce syngas, a synthetic gas prima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
