A co-shift process for methanol synthesis

Abstract

The invention relates to a CO conversion process for methanol synthesis, which is characterized in that it includes the following steps: the crude gas first enters a low-pressure steam generator to cool down and separates the liquid to adjust the water-gas ratio, and the crude gas after the liquid separation is divided into two streams, About 45% to 55% of one strand is used as non-shifted gas, and the rest is used as the second strand after being heated up, detoxified, and divided again, and then enters the parallel air-cooled shift furnace and isothermal shift furnace for isothermal shift and heat recovery. After that, it is mixed with the first non-shifted gas and used as synthesis gas to control the H in the synthesis gas 2 The molar ratio with CO is controlled at 2.1-2.3. The invention produces medium-pressure saturated steam and low-pressure superheated steam by-products, and the air-cooled shift furnace uses shift gas as a refrigerant; multiple split-share shifts are adopted, the process is short, the size of the shift furnace is small, and there is no risk of overheating. The isothermal shift furnace used The heat exchange area can be adjusted, the pressure fluctuation of the by-product medium pressure steam is small, and the system operation is more stable.

Description

technical field [0001] The invention relates to the technical field of carbon monoxide conversion, and specifically refers to a CO conversion process supporting methanol synthesis. Background technique [0002] Since the beginning of the 21st century, my country's chemical industry using coal as raw material has developed rapidly. Starting from the shell pulverized coal gasification process introduced in the Netherlands, a variety of independent coal gasification processes have been developed. CO in the raw gas produced by such processes The dry basis content is generally high, reaching more than 60%. For the production equipment that adopts the gasification process to produce syngas and downstream C1 chemical products, it is generally necessary to remove CO in the raw material gas through a shift reaction, which consumes water vapor to produce H2, while changing CO into CO2 which is easy to remove. Downstream products include hydrogen production, synthetic ammonia, methanol ...

AI Technical Summary

Problems solved by technology

[0008] The technical problem to be solved by the present invention is to provide a CO shift process for methanol synthesis in view of the current state of the art, which can effectively solve the problem of overheating of traditional adiabatic shift furnaces and medium-pressure steam systems of isothermal shift furnaces after the catalyst is raised in the middle and late stages. Variable area isothermal transformation process with large pressure fluctuation

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