Anhydrous low-temperature methanol washing device and production method

Abstract

The invention belongs to an anhydrous low-temperature methanol washing device and a production method, the anhydrous low-temperature methanol washing device comprises a raw material gas pipeline and a methanol washing tower, the raw material gas pipeline is connected with a raw material gas inlet of the methanol washing tower through a raw material gas dehydration unit, and the top of the methanol washing tower is connected with a purified gas pipe network; a liquid phase outlet at the bottom of the methanol washing tower is connected with an inlet of a lean methanol spraying pipeline at the middle upper part of the methanol washing tower through a rich methanol treatment unit; the device is simple in structure and reasonable in design, moisture in raw material gas is completely removed through the raw material gas dehydration unit, a lean methanol solution is sprayed in the methanol washing tower, and the characteristic that the water content in lean methanol / rich methanol / circulating methanol is less than 0.01% is realized, so that corrosion of related equipment is avoided, the acquisition cost of the raw material gas methanol spraying device and the methanol-water separation tower is saved, and the separation of methanol and water in the subsequent process is omitted.

Description

technical field [0001] The invention belongs to the technical field of gas purification, and in particular relates to an anhydrous low-temperature methanol washing device and a production method for eluting and removing impurity gases such as carbon dioxide and hydrogen sulfide in process gas with low-temperature methanol. Background technique [0002] Low-temperature methanol washing technology is widely used in the removal of acid gases such as carbon dioxide and hydrogen sulfide in the gas industry due to its technical advantages. In the low-temperature methanol washing process, low-temperature methanol absorbs acid gases such as carbon dioxide and hydrogen sulfide to become methanol-rich liquid, which has strong acidity; especially when the methanol-rich liquid contains water, its acidity and corrosion will intensify, causing Parts and inner walls are corroded, which may lead to defects such as tray falling off and methanol-rich filter clogging in severe cases, which is ...

AI Technical Summary

Problems solved by technology

In the low-temperature methanol washing process, low-temperature methanol absorbs acid gases such as carbon dioxide and hydrogen sulfide to become methanol-rich liquid, which has strong acidity; especially when the methanol-rich liquid contains water, its acidity and corrosion will intensify, causing Parts and inner wall are corroded, which may lead to defects such as tray falling off and methanol-rich filter clogging in severe cases, which is not conducive to safe and stable operation of production

The conventional low-temperature methanol washing process absorbs the moisture in the feed gas by spraying methanol and obtains aqueous methanol. The aqueous methanol is rectified in the methanol-water separation tower, methanol vapor is obtained from the top of the tower, and methanol-containing wastewater, methanol and water are obtained from the bottom of the tower. It is extremely difficult to completely separate, and the methanol vapor will bring water into the circulating methanol, resulting in 0.1-0.5% water in lean methanol at the top of the methanol scrubber, which will eventually lead to enhanced acidity and corrosion of methanol-rich water

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