Method for recovering methanol from tail gas washing water in low-temperature methanol washing technology

Abstract

The invention provides a method for recovering methanol from tail gas washing water in a low-temperature methanol washing technology. The method comprises the following flows: exchanging heat of washing water from a tail gas washing tower and wastewater at the bottom of a methanol / water separating tower in a heat exchanger, and sending the wastewater out of a boundary region for processing after cooling; heating the washing water to about 100 DEG C, feeding the washing water into the methanol / water separating tower, providing a distributor in the methanol / water separating tower, evenly distributing the heated washing water on a tower tray through the distributer; distilling and separating the washing water in the methanol / water separating tower after quickly releasing the dissolved CO2, and recovering methanol after condensing an overhead component. By adopting the method for recovering methanol from the tail gas washing water in the low-temperature methanol washing technology disclosed by the invention, corrosion of acid washing water on the wall of the methanol / water separating tower is reduced to the lowest extent; the service life of the methanol / water separating tower can be prolonged; meanwhile, the device and operation costs are reduced.

Description

technical field [0001] The invention relates to a tail gas purification method of an acid gas absorbing device in a low-temperature methanol washing process, in particular to a method for recovering methanol in tail gas washing water in a low-temperature methanol washing process. Background technique [0002] The low-temperature methanol washing process has been widely used in synthetic ammonia, synthetic methanol and other oxo synthesis, hydrogen production, city gas and natural gas desulfurization, and other gas purification processes and devices. The process of low-temperature methanol washing is to use methanol to absorb the acid gas in the mixed gas, and then separate the methanol from the acid gas through decompression desorption, gas stripping and heating, so as to purify the mixed gas and recover methanol. [0003] The tail gas of the low-temperature methanol washing process contains a small amount of methanol, which will pollute the environment and cause the loss of...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a method for recovering methanol from tail gas washing water in a low-temperature methanol washing process, which can solve the technical problem that the washing water of the tail gas washing tower corrodes the methanol / water separation tower, and reduce the impact of washing water on the methanol process during rectification separation and recovery. Corrosion of the methanol / water separation tower greatly improves the service life of the methanol / water separation tower and reduces device costs

Images