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Coal liquefaction is a process of converting coal into liquid hydrocarbons: ... The reaction takes place in a tubular reactor at a temperature between 430 °C (810 ...
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. [1]
Alternatively, iron sulfide present in the coal may have sufficient catalytic activity for the process, which was the original Bergius process. [2] The mixture is pumped into a reactor. The reaction occurs at between 400 and 500 °C and 20 to 70 MPa hydrogen pressure. The reaction produces heavy oils, middle oils, gasoline, and gases.
As an example of the latter, a "major commercial application of liquefaction is the liquefaction of air to allow separation of the constituents, such as oxygen, nitrogen, and the noble gases." [ 4 ] Another is the conversion of solid coal into a liquid form usable as a substitute for liquid fuels.
In this case there is no chemical interaction between coal and oxidizer before the reaction zone. The gas produced in the reaction zone passes solid products of gasification (coke and ashes), and CO 2 and H 2 O contained in the gas are additionally chemically restored to CO and H 2. As compared to the "direct blowing" technology, no toxic by ...
If the refiner wants to produce gasoline, the syngas is routed into a Fischer–Tropsch reaction. This is known as indirect coal liquefaction. If hydrogen is the desired end-product, however, the syngas is fed into the water gas shift reaction, where more hydrogen is liberated: CO + H 2 O → CO 2 + H 2
In this process, coal is liquefied by heating in the presence of hydrogen gas (hydrogenation). Dry coal is mixed with heavy oil recycled from the process. Catalysts are typically added to the mixture. The reaction occurs at between 400 °C (752 °F) to 500 °C (932 °F) and 20 to 70 MPa hydrogen pressure. [34]
Coal is cleaned, crushed and fed to the slurry dryer, where water is removed. The dry crushed coal is slurried with the hydrogen donor recycle solvent. The coal slurry is treated with hydrogen and heated in a liquefaction slurry furnace. The liquefaction occurs at 840 °F (449 °C) and 2,000 pounds per square inch (14,000 kPa).