Methanol synthesis system and methanol synthesis method

Abstract

The invention provides a methanol synthesis system and a methanol synthesis method. The methanol synthesis system comprises a booster expander, a multi-stage methanol synthesis device and a heater. Afeed gas inlet is formed in the booster expander; each stage of methanol synthesis device comprises a synthesis tower, a gas-gas heat exchanger, a water cooler and a methanol separator, which are connected in sequence; the gas-gas heat exchanger of the first-stage methanol synthesis device is communicated with the booster expander, and the gas-gas heat exchangers of the other stages of the methanol synthesis device except the first-stage of the methanol synthesis device are all communicated with the methanol separator of the previous stage of the methanol synthesis device. The heater is respectively connected with the methanol separator of the last stage of the methanol synthesis device and the booster expander, the purge gas separated by the methanol separator enters the heater and is heated, the residual pressure and residual heat of the purge gas are utilized to pressurize the feed gas flowing through the booster expander, and the aims of improving the total carbon conversion rate,saving energy and reducing consumption are fulfilled.

Description

technical field [0001] The invention belongs to the technical field of methanol synthesis technology, and in particular relates to a methanol synthesis system and a methanol synthesis method. Background technique [0002] Methanol, commonly known as "wood alcohol", is not only an important basic chemical raw material, widely used in pesticides, medicines, coatings and national defense industries, but also a new type of energy, used as a clean liquid fuel to reduce environmental pressure. There are many ways to synthesize methanol. At present, natural gas, coal gas, and coke oven gas are used in China to produce methanol, all of which belong to the technology of synthesis gas under high temperature, high pressure and catalyst action. The reaction rate is low. After the reacted gas is cooled to separate the liquid, most of the unreacted gas is used as a cycle gas, which needs to be pressurized in the combined compressor, and mixed with the pressurized raw material gas to enter...

AI Technical Summary

Problems solved by technology

There are many ways to synthesize methanol. At present, natural gas, coal gas, and coke oven gas are used in China to produce methanol, all of which belong to the technology of synthesis gas under high temperature, high pressure and catalyst action. The reaction rate is low. After the reacted gas is cooled to separate the liquid, most of the unreacted gas is used as a cycle gas, which needs to be pressurized in the combined compressor, and mixed with the pressurized raw material gas to enter the methanol synthesis system. continue to synthesize methanol

In addition, a small amount of gas is discharged as purge gas, which is used as fuel gas after being decompressed to normal pressure. The residual pressure and waste heat of the purge gas are not collected and utilized, resulting in waste

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