Combined process for preparing power generation co-production synthesis ammonia feed gas by using crude gas containing CH4

Abstract

The invention relates to a combined process for preparing a power generation co-production synthesis ammonia feed gas by using a crude gas containing CH4, comprising the following steps of: firstly enabling the preprocessed crude gas containing CH4 to enter a low-temperature sulfur tolerant shift device to transform CO into hydrogen; then acquiring high-purity hydrogen through a pressure swing adsorption device; preparing the synthesis ammonia feed gas through the acquired high-purity hydrogen and high-purity nitrogen from an air separation device; and using a pressure swing adsorption tail gas as a refined fuel gas. Compared with the prior art, the combined process provided by the invention substitutes for the traditional process comprising a CH4 reforming procedure, a transformation procedure, a desulfuration and decarburization procedure adopting a low-temperature methanol washing method or a polyethylene glycol dimethyl ether method and a methanol-methanation refining procedure, achieves the standard of a synthesis ammonia refining gas by desorbing harmful gas carbon monoxide, carbon dioxide and sulfur impurities through a pressure swing adsorption process, meets the requirements on the synthesis of synthesis ammonia and has the advantages of low operating cost, obvious environmental-friendly effect and high resource utilization ratio.

Description

technical field [0001] The invention relates to the technical field of refining feed gas for ammonia synthesis, in particular to a combined process for producing feed gas for power generation and co-production of ammonia synthesis by using methane-containing crude gas. Background technique [0002] Contains CH 4 Crude gas (such as BGL gasification gas, etc.) is a kind of rich CH 4 main source of gas. Due to CH 4 It is an inert gas in the synthetic ammonia or methanol synthesis reaction. At present, the main domestic concern is how to solve the conversion and reforming of the alkane components in the crude gas. The combined process flow of traditional ammonia synthesis feed gas treatment is as follows: figure 1 Shown, CH 4 into CO and H 2 , and at the same time reduce the content of inert gas components, and then convert CO into H through the conversion process 2 , and then through the process of desulfurization and decarburization (such as low-temperature methanol was...

AI Technical Summary

Problems solved by technology

Due to the restriction of chemical balance, the conversion rate of methanol is not very high, so the methanation process still produces > 0.5% inert gas methane, and the consumption of raw material gas for ammonia synthesis is also high

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