Two-stage double-separation methanol production method

Abstract

The invention discloses a two-stage double-separation methanol production method which comprises the following steps of: (1) compressing a second mixed gas containing a second complementary gas and asecond lean gas by a circulator, feeding the compressed second mixed gas into a first reactor for reaction, and discharging a first tower outlet gas; (2) recovering methanol from the first tower outlet gas to form a first lean gas; (3) mixing the first lean gas and the first complementary gas to form a first mixed gas, enabling the first mixed gas to enter a second reactor for reaction, and discharging a second tower outlet gas; and (4) recovering methanol from the second tower outlet gas to form a second lean gas, heating the second mixed gas by the first tower outlet gas through a first heatexchanger, and heating the first mixed gas by the second tower outlet gas through a second heat exchanger. In the application, the material circularly flows between the two reactors, so that the volume ratio of the first complementary gas to the second complementary gas is approximately the same, the reaction parameters of the two reactors are also approximately the same, the reaction of the tworeactors can be controlled in the same manner, and the production stability is improved.

Description

technical field [0001] The invention relates to a two-stage double-separation methanol production method. Background technique [0002] Methanol synthesis usually uses synthesis gas and hydrogen as raw materials for synthesis, and then the reaction mixture gas discharged from the reactor passes through a gas-liquid separator to separate the condensed methanol and make the unreacted gas separated by the gas-liquid separator The gas is returned to the reactor to continue the reaction, and fresh synthesis gas called make-up gas is added to the reaction system to continue the reaction. In the production process, in order to improve the reaction efficiency, multi-stage reactors are generally used, and the first The first-stage reactor is constantly replenished with fresh synthesis gas, and the last-stage reactor is generally carried out by self-circulation. In this reaction system, it is necessary to set up different types of reactors for different gas concentrations, so that the...

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Problems solved by technology

[0002] Methanol synthesis usually uses synthesis gas and hydrogen as raw materials for synthesis, and then the reaction mixture gas discharged from the reactor passes through a gas-liquid separator to separate the condensed methanol and make the unreacted gas separated by the gas-liquid separator The gas is returned to the reactor to continue the reaction, and fresh synthesis gas called make-up gas is added to the reaction system to continue the reaction. In the production process, in order to improve the reaction efficiency, multi-stage reactors are generally used, and the first The first-stage reactor is constantly replenished with fresh synthesis gas, and the last-stage reactor is generally carried out by self-circulation. In this reaction system, it is necessary to set up different types of reactors for different gas concentrations, so that the types of reactors increase, not only The maintenance cost of the reactor is increased, and different control methods and control points are required due to different forms of reactors, which also increases the difficulty of production stability

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