Method for producing low-carbon alcohol and co-producing natural gas and urea with syngas and coke oven gas

Abstract

A method for syngas and coke oven gas to produce low-carbon alcohol and co-produce natural gas and urea is to mix crude synthesis gas and coke oven gas to form a raw material gas that satisfies the hydrogen-carbon ratio of low-carbon alcohol synthesis; the raw material gas is washed with methanol at low temperature, The released hydrogen sulfide is desulfurized and recovered, and the removed carbon dioxide is purified by CO2 stripping; the raw material gas washed with low-temperature methanol is subjected to methane separation, and the released methane is made into LNG or CNG, and the pure gas after methane separation is used for synthesis of low-carbon Alcohol reaction, the gas obtained as purge gas enters the PSA for separation, the separated gas mainly includes CO, CO2 and CH4, etc., and returns to the low-temperature methanol washing cycle, and the separated H2 and N2 obtained by air separation are reacted to synthesize ammonia to obtain synthetic ammonia; after purification CO2 reacts with synthetic ammonia to synthesize urea to produce urea products; the obtained liquid phase products are separated from low-carbon alcohols to obtain low-carbon alcohol products. The invention has the advantage of improving the utilization rate of raw gas.

Description

technical field [0001] The invention belongs to a method for synthesizing low-carbon alcohol, in particular to a method for producing low-carbon alcohol from synthesis gas and coke oven gas and co-producing natural gas and urea. Background technique [0002] Low carbon alcohol usually refers to the mixture of C1~C5 alcohols. The application prospect is very wide: low-carbon alcohol can be used as an alternative fuel, although its calorific value is low, it is fully combusted and emits less CO, NOx, hydrocarbons, etc. during combustion, which is an environmentally friendly fuel; low-carbon alcohol It can also be used as a fuel additive. The currently used gasoline additive methyl tert-butyl ether will eventually be banned with the advancement of technology due to problems such as storage and transportation, which provides an opportunity for the development of low-carbon alcohols. Moreover, the low-carbon alcohol has a high octane number, and has good explosion-proof and sho...

AI Technical Summary

Problems solved by technology

[0007] The present invention is based on the composition of coke oven gas with more hydrogen and less carbon, while the synthesis gas has more carbon and less hydrogen and contains a large amount of CH 4 The characteristics of the two complement each other to meet the hydrogen-to-carbon ratio for the synthesis of low-carbon alcohols, so as to solve the shortcomings of carbon supplementation in the production of low-carbon alcohols using coke oven gas alone or the need for hydrogen supplementation in the production of low-carbon alcohols from syngas alone, and Can by-produce LNG (liquefied natural gas) or CNG (compressed natural gas)

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