Carbon elimination technique using dimethyl carbonate as absorbing agent

Abstract

The invention discloses a decarburization process which adopts dimethyl carbonate as an absorbent, the process has the following steps: firstly, material which contains CO2 is decarbonized through the absorption of the dimethyl carbonate, then absorbent rich solution after absorbing the CO2 is regenerated through two-stage throttling expansion and nitrogen desorption, and the nitrogen is discharged out of the boundary region through exhaust purification after the CO2 produced by the throttling expansion is carried out with water washing and desorption. The dimethyl carbonate decarburization process provided by the invention has the following advantages: compared with the commonly used carbonic allyl ester method in the current industry, the energy consumption can be reduced by more than 30 percent; compared with the polyethylene glycol dimethylether method, the solvent price is lower, and the polymerization loss is reduced by more than 50 percent; compared with the low temperature methanol scrubbing process, the operating temperature is milder, and the equipment investment is reduced by more than 30 percent. The CO2 removal efficiency of the invention can reach more than 95 percent.

Description

technical field [0001] The invention relates to a method for absorbing and removing CO from medium and high pressure gas mixtures, including synthesis gas, shift gas and IGCC gas 2 The technology belongs to the technical field of chemical engineering. Background technique [0002] Global warming has become an undisputed fact. Greenhouse gas CO 2 emissions are a major contributor to climate warming. How to get from rich CO 2 Capture and separation of CO in the gas mixture of synthetic gas, shift gas and IGCC gas 2 extremely important. [0003] According to different application occasions and the pressure of feed gas, the decarburization method can be divided into dry method and wet method. Dry methods include adsorption methods and membrane methods, and are generally applicable to CO 2 Where the concentration is low; the wet method can be divided into chemical absorption method and physical absorption method, and the chemical absorption method is mostly used in occasi...

AI Technical Summary

Problems solved by technology

[0007] In view of the long process flow and large equipment investment of the existing low-temperature methanol washing method, the small absorption capacity of the absorbent of the propylene carbonate method, the large circulation volume, and the polyethylene glycol Methyl ether method has the disadvantages of high cost and prone to polymerization loss. The present invention provides a decarburization process using dimethyl carbonate as an absorbent to further simplify the process and reduce costs.

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