Method and apparatus for producing hydrocarbons by synthesis gas from coal

Abstract

The invention discloses a method for producing hydrocarbons by synthesis gas from coal. Methanol or methanol and dimethyl ether are synthesized by raw gas firstly, and then hydrocarbons are synthesized, wherein the methanol or methanol and dimethyl ether are subjected to a dehydration reaction to generate liquid hydrocarbons, reaction gas for hydrocarbon synthesis is subjected to gas-liquid separation to obtain liquid hydrocarbon products, then a part of the reaction gas are circulated and returned to mix with the raw gas before methanol synthesis, so as to perform methanol synthesis and hydrocarbon synthesis reactions again, and the other part of the reaction gas is discharged or sent to the next section for reaction, as needed. The invention also discloses an apparatus used in the method. The method of the invention adopts a two-step reaction isobaric operation of pressure decrease in methanol synthesis or methanol and dimethyl ether synthesis from synthesis gas in hydrocarbon production by synthesis gas, and pressure increase in hydrocarbon production by dehydration; a catalyst for methanol synthesis and a catalyst for dimethyl ether are filled in a layered manner according to the design requirements, which prevents the reduced methanol catalyst of active copper from oxidation poisoning due to mixing and filling of the two catalysts; the method of the invention has the advantages of short flow, few apparatuses, low investment, saved energy consumption and the like.

Description

technical field [0001] The invention relates to the technical field of chemical engineering, in particular to a method and equipment for producing hydrocarbons from coal-based synthesis gas. Background technique [0002] The most common method for coal-to-synthesis gas to produce hydrocarbons is to use F-T reaction, such as the large-scale coal-to-oil plant successfully built by Sasol Company in South Africa, but the composition of the F-T reaction product is complex, and further hydrogenation modification is required to refine the product, which requires a long process and equipment Many, big investment. Another method is to synthesize methanol from synthesis gas first, then heat and vaporize liquid methanol, and dehydrate under the action of a catalyst to obtain hydrocarbon oil, that is, industrial methanol dehydration to gasoline. The oil product gasoline is of good quality, but it is necessary to build a methanol synthesis unit and a methanol-to-gasoline unit separately...

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Problems solved by technology

[0003] In the prior art method of producing gasoline from synthesis gas through methanol and dimethyl ether, for example, Chinese invention patent application 200710185293.5, methanol and methanol dehydration catalyst are mixed in the first-stage reactor and then loaded. Methanol is generated, and the dehydration reaction of the generated methanol occurs immediately, that is, 2CH 3 OH=(CH 3 ) 2 O+H 2 O, a large amount of water generated by the dehydration reaction makes the reduced monovalent active copper Cu in the methanol catalyst + Oxidized to divalent copper, thereby losing the catalytic effect of methanol synthesis

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