Equipment and method for low-temperature methanol double washing based on heat exchange and modified methanol

Abstract

The invention discloses equipment for low-temperature methanol double washing based on heat exchange and modified methanol. The equipment comprises a process gas absorption tower, a flash tower, a CO2 desorption tower, an H2S concentration tower, a methanol regeneration tower, a methanol-water separation tower and a tail gas water washing tower; the flash tower and the CO2 desorption tower are respectively connected with the process gas absorption tower, the H2S concentration tower and the methanol regeneration tower are respectively connected with the flash tower, the methanol-water separation tower is connected with the methanol regeneration tower, and the tail gas washing tower is connected with the H2S concentration tower; CO2 gas and a methanol-rich solution in raw material gas are separated out by utilizing the process gas absorption tower, CO2 gas is resolved out by utilizing the CO2 desportion tower, H2S gas in the methanol-rich solution is flashed out by utilizing the flash tower, a methanol-poor solution after flash evaporation sequentially passes through the methanol regeneration tower and the methanol-water separation tower, and tail gas overflowing from the top of the H2S concentration tower is discharged after being washed by the tail gas washing tower; and the equipment is reasonable in structural design, the methanol consumption is reduced by adjusting the methanol recycling process, and the production cost is saved.

Description

technical field [0001] The invention relates to the technical field of low-temperature methanol washing, in particular to a device and method for low-temperature methanol double washing based on heat exchange and modified methanol. Background technique [0002] The low-temperature methanol washing process is a purification process that uses physical absorption to separate the shift gas. 2 、H 2 S and carbonyl sulfide and other acid gases have a good absorption effect, and the gas is completely dried. At the same time, the acid gases are classified and recovered during the methanol regeneration process. At present, the low-temperature methanol washing process is widely used in chemical fields such as coal-to-synthetic ammonia and coal-to-methanol. Its technology is mature, the gas purification degree is high, and the regenerated methanol meets the production requirements. [0003] Since gas dissolving in liquid is an exothermic process, as the solubility of acid gas in low-t...

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Problems solved by technology

Therefore, in order to ensure the absorption capacity of methanol to acid gas and reduce the volume circulation, it is necessary to maintain the methanol washing device to operate at low temperatu

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