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The pyrolysis process is the thermal decomposition of materials at elevated temperatures, often in an inert atmosphere. It involves a change of chemical composition. The word is coined from the Greek-derived elements pyro "fire", "heat", "fever" and lysis "separating".
The Fischer–Tropsch process is a collection of chemical reactions that converts a mixture of carbon monoxide and hydrogen, known as syngas, into liquid hydrocarbons. These reactions occur in the presence of metal catalysts, typically at temperatures of 150–300 °C (302–572 °F) and pressures of one to several tens of atmospheres. The Fischer–Tropsch process is an important reaction in both coal liquefaction and gas to liquids technology for producing liquid hydrocarbons.
In industrial chemistry, coal gasification is the process of producing syngas—a mixture consisting primarily of carbon monoxide (CO), hydrogen, carbon dioxide, methane, and water vapour —from coal and water, air and/or oxygen.
Sasol Limited is an integrated energy and chemical company based in Sandton, South Africa. The company was formed in 1950 in Sasolburg, South Africa and built on processes that were first developed by German chemists and engineers in the early 1900s. Today, Sasol develops and commercializes technologies, including synthetic fuels technologies, and produces different liquid fuels, chemicals, nuclear, coal tar and electricity.
Shale oil is an unconventional oil produced from oil shale rock fragments by pyrolysis, hydrogenation, or thermal dissolution. These processes convert the organic matter within the rock (kerogen) into synthetic oil and gas. The resulting oil can be used immediately as a fuel or upgraded to meet refinery feedstock specifications by adding hydrogen and removing impurities such as sulfur and nitrogen. The refined products can be used for the same purposes as those derived from crude oil.
Coal liquefaction is a process of converting coal into liquid hydrocarbons: liquid fuels and petrochemicals. This process is often known as "Coal to X" or "Carbon to X", where X can be many different hydrocarbon-based products. However, the most common process chain is "Coal to Liquid Fuels" (CTL).
Synthetic fuel or synfuel is a liquid fuel, or sometimes gaseous fuel, obtained from syngas, a mixture of carbon monoxide and hydrogen, in which the syngas was derived from gasification of solid feedstocks such as coal or biomass or by reforming of natural gas.
Gas to liquids (GTL) is a refinery process to convert natural gas or other gaseous hydrocarbons into longer-chain hydrocarbons, such as gasoline or diesel fuel. Methane-rich gases are converted into liquid synthetic fuels. Two general strategies exist: (i) direct partial combustion of methane to methanol and (ii) Fischer–Tropsch-like processes that convert carbon monoxide and hydrogen into hydrocarbons. Strategy ii is followed by diverse methods to convert the hydrogen-carbon monoxide mixtures to liquids. Direct partial combustion has been demonstrated in nature but not replicated commercially. Technologies reliant on partial combustion have been commercialized mainly in regions where natural gas is inexpensive.
The Bergius process is a method of production of liquid hydrocarbons for use as synthetic fuel by hydrogenation of high-volatile bituminous coal at high temperature and pressure. It was first developed by Friedrich Bergius in 1913. In 1931 Bergius was awarded the Nobel Prize in Chemistry for his development of high-pressure chemistry.
Fluid Catalytic Cracking (FCC) is the conversion process used in petroleum refineries to convert the high-boiling point, high-molecular weight hydrocarbon fractions of petroleum into gasoline, olefinic gases, and other petroleum products. The cracking of petroleum hydrocarbons was originally done by thermal cracking, now virtually replaced by catalytic cracking, which yields greater volumes of high octane rating gasoline; and produces by-product gases, with more carbon-carbon double bonds, that are of greater economic value than the gases produced by thermal cracking.
The Synthetic Liquid Fuels Program was a program run by the United States Bureau of Mines to create the technology to produce synthetic fuel from coal and oil shale. It was initiated in 1944 during World War II. The Synthetic Liquid Fuels Act approved on April 5, 1944 authorized the use of US$30 million over a five-year period for
the construction and operation of demonstration plants to produce synthetic liquid fuels from coal, oil shales, agricultural and forestry products, and other substances, in order to aid the prosecution of the war, to conserve and increase the oil resources of the Nation, and for other purposes.
The Karrick process is a low-temperature carbonization (LTC) and pyrolysis process of carbonaceous materials. Although primarily meant for coal carbonization, it also could be used for processing of oil shale, lignite or any carbonaceous materials. These are heated at 450 °C (800 °F) to 700 °C (1,300 °F) in the absence of air to distill out synthetic fuels–unconventional oil and syngas. It could be used for a coal liquefaction as also for a semi-coke production. The process was the work of oil shale technologist Lewis Cass Karrick at the United States Bureau of Mines in the 1920s.
An integrated gasification combined cycle (IGCC) is a technology using a high pressure gasifier to turn coal and other carbon based fuels into pressurized gas—synthesis gas (syngas). It can then remove impurities from the syngas prior to the electricity generation cycle. Some of these pollutants, such as sulfur, can be turned into re-usable byproducts through the Claus process. This results in lower emissions of sulfur dioxide, particulates, mercury, and in some cases carbon dioxide. With additional process equipment, a water-gas shift reaction can increase gasification efficiency and reduce carbon monoxide emissions by converting it to carbon dioxide. The resulting carbon dioxide from the shift reaction can be separated, compressed, and stored through sequestration. Excess heat from the primary combustion and syngas fired generation is then passed to a steam cycle, similar to a combined cycle gas turbine. This process results in improved thermodynamic efficiency compared to conventional pulverized coal combustion.
Carbochemistry is the branch of chemistry that studies the transformation of coal-(bituminous coal, coal tar, anthracite, lignite, graphite, and charcoal) into useful products and raw materials. The processes that are used in carbochemistry include degasification processes such as carbonization and coking, gasification processes, and liquefaction processes.
Coal slurry is a mixture of solids and liquids produced by a coal preparation plant.
The Lurgi–Ruhrgas process is an above-ground coal liquefaction and shale oil extraction technology. It is classified as a hot recycled solids technology.
Thermal dissolution is a method of liquefaction of solid fossil fuels. It is a hydrogen-donor solvent refining process. It may be used for the shale oil extraction and coal liquefaction. Other liquids extraction processes from solid fuels are pyrolysis and hydrogenation. Compared to hydrogenation, the process of thermal dissolution has milder conditions, simpler process, and no consumption of catalyst.
In the United States, synthetic fuels are of increasing importance due to the price of crude oil, and geopolitical and economic considerations.
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.
Syngas to gasoline plus (STG+) is a thermochemical process to convert natural gas, other gaseous hydrocarbons or gasified biomass into drop-in fuels, such as gasoline, diesel fuel or jet fuel, and organic solvents.
References
- 1 2 3 McGuckin, John (February 1982). "Technical Report. Exxon Donor Solvent Coal Liquefaction Process" (PDF). United States Environmental Protection Agency . Retrieved April 11, 2016.
- 1 2 3 Kent, James A. (2013). Riegel's Handbook of Industrial Chemistry (9 ed.). Springer Science & Business Media. p. 574. ISBN 9781475764314.
- ↑ Probstein, Ronald F.; Hicks, R. Edwin (2013). Synthetic Fuels. Dover Books on Aeronautical Engineering. Courier Corporation. p. 301. ISBN 9780486319339.
- ↑ Maa, Peter S.; Trachte, Ken L.; Williams, Richard D. (2013). "Solvent Effects in Exxon Donor-Solvent Coal Liquefaction". In Schlosberg, Richard H. (ed.). Chemistry of Coal Conversion. Springer Science & Business Media. p. 317. ISBN 9781489936325.
- ↑ Lee, Sunggyu; Speight, James G.; Loyalka, Sudarshan K. (2014). Handbook of Alternative Fuel Technologies. Green Chemistry and Chemical Engineering (2 ed.). CRC Press. pp. 100–101. ISBN 9781466594562.
- ↑ Neavel, R. C.; Knights, C. F.; Schulz, H. (March 20, 1981). "Exxon Donor Solvent Liquefaction Process". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 300 (1453): 141–156. Bibcode:1981RSPTA.300..141N. doi:10.1098/rsta.1981.0055. ISSN 1471-2962. S2CID 94170659.
- ↑ Mitchell, Willard N.; Trachte, Kenneth L.; Zaczepinski, Sam (1979). "Performance of Low Rank Coals in the Exxon Donor Solvent Process". Industrial & Engineering Chemistry Product Research and Development. 18 (4): 311–314. doi:10.1021/i360072a016.
- ↑ Schobert, Harold H. (1995). Lignites of North America. Coal Science and Technology. Vol. 23. Elsevier. p. 641. ISBN 9780080544625.