Process for soda ash production through converted gas pressure swing adsorption and ammonia water combined decarbonization

Abstract

The invention relates to a process for soda ash production through converted gas pressure swing adsorption and ammonia water combined decarbonization. According to the process, converted gas goes into a pressure swing adsorption device to be subjected to carbon dioxide removal, and the converted gas is called as coarse decarburized gas when the concentration of carbon dioxide reaches 4-5%; meanwhile, carbon-dioxide-rich desorbed gas with the concentration being more than 95% is obtained and called as product gas; the product gas is sent to a combined soda carbonization working section; the decarburized gas goes into a strong ammonia water carbonization tower to be subjected to deep purification to enable the concentration of carbon dioxide to be 0.1-0.2% (the concentration of carbon dioxide can be controlled within 0.8-1.0% if there is a combined methanol device); outlet gas of the carbonization tower goes into a recycled ammonia gas washing tower; outlet gas of the recycled ammonia gas washing tower is sent to an ammonia synthesis compressor; diluted ammonia water flowing out of the bottom of the recycled ammonia gas washing tower is sent to a gaseous ammonia absorption tower to be absorbed to produce strong ammonia water; the strong ammonia water is used for the carbonization tower, and carbonated ammonia water at a bottom outlet of the carbonization tower is sent to a combined soda carbonization tower for use.

Description

technical field [0001] The invention relates to the fields of chemical industry and environmental protection, and is a method for effectively utilizing production waste gas to reduce production energy consumption and raw material consumption. Background technique [0002] 1. For the method of 1.7MPa shift gas decarburization for the production of soda ash, the liquid phase decarburization technology is generally used, because the liquid phase decarburization technology has little nitrogen loss, and the carbon dioxide concentration of the obtained analytical gas is as high as 96%~99%, but the liquid phase decarburization technology Phase decarburization technologies are energy-intensive and generally less environmentally friendly than PSA technologies. [0003] 2. For the technology of 1.7MPa shift gas decarburization for the production of soda ash, two-stage decarburization is usually used, and the desorption gas of 96%~99% concentration of carbon dioxide can be obtained in ...

AI Technical Summary

Problems solved by technology

The carbon dioxide concentration of the purification gas in the second stage of pressure swing adsorption reaches below 0.2% (the carbon dioxide concentration of the co-alcohol purification gas reaches 0.8~1.0%), and the concentration of carbon dioxide in the desorption gas is generally around 55%. Because it contains hydrogen and carbon monoxide, it cannot be used for joint carbonization. because of security risks

Moreover, the loss of nitrogen in the second-stage desorption gas is very large, and more nitrogen must be added in the gas generation process than in the liquid-phase method for decarburization, which affects the output power of the compressor.

[0004] 3. The carbon dioxide concentration of the desorbed gas by one-stage shift gas pressure swing adsorption decarburization device can usually only reach 90~91%, almost all of the carbon dioxide is used for joint carbonization, and the carbon dioxide concentration of the purified gas can reach below 0.2% (coalcohol purified gas carbon dioxide up to 0.8~1.0%), but the loss of nitrogen is still very large, and it is necessary to supplement more nitrogen in the gas generation process than liquid-phase decarburization, which affects the output power of the compressor