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What are the dry distillation, gasification and liquefaction of coal? (For example, coal is fractionated according to different boiling points. . . )
Dry distillation of coal: refers to the process that coal is decomposed by heating under the condition of being isolated from air to produce coke (or semi-coke), coal tar, crude benzene, gas and other products. ?

According to the final heating temperature, it can be divided into three types: 900 ~ 1 100℃ is high temperature dry distillation, that is, coking; Dry distillation at 700 ~ 900℃; 500 ~ 600℃ is low temperature dry distillation.

Coal gasification: refers to the process that coal reacts with gasifying agents (O2, H2O) at a certain temperature and pressure (incomplete combustion) to generate synthesis gas, also known as water gas and semi-water gas (mainly composed of CO+H2+CO2, and a small amount of CH4, N2, H2S, COS, etc.). ). The gasification reaction formula can be simply considered as: C+O2+H2O → Co+H2+CO2-Q.

According to the pressure, it is divided into atmospheric gasification and pressurized gasification; According to the purity of oxygen, it can be divided into oxygen-enriched and pure oxygen. According to the feed form, it can be divided into coal slurry gasification and dry powder gasification; According to the bed form, it can be divided into fixed bed gasification, fluidized bed gasification and entrained flow gasification.

Coal liquefaction is actually a process of coal-to-oil production, which is divided into two processes: direct liquefaction and indirect liquefaction.

Direct liquefaction refers to the process of directly synthesizing liquid oil products (pre-asphaltene and asphaltene) by hydrogenation of solid coal in solvent, catalyst, high pressure and certain temperature (after a certain period of time).

Indirect liquefaction refers to the process of generating synthesis gas (CO+H2) from coal gasification, and then synthesizing liquid oil from the synthesis gas at a certain temperature, pressure and catalyst, also known as Fischer-Tropsch (F-T) synthesis.

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