Novel absorbent for capturing and separating carbon dioxide

Abstract

The invention belongs to the technical field of gas separation and purification and relates to a novel absorbent for capturing and separating CO2 in mixed gas. An active amine compound aqueous solution with a special structure is used as an absorbent; two functional groups, namely a primary amine functional group and a tertiary amine functional group, are contained in the active amine molecules; primary amine is mainly used for improving the absorption rate, and tertiary amine is mainly used for increasing the absorption amount and reducing the desorption temperature; and the two types of amine can promote activation. The active amine compound aqueous solution comes into contact with treated gas to purify gas; and the concentration of the absorbent is 5-80wt%. The absorbent provided by the invention is wide in amine concentration range, high in CO2 absorption rate, large in absorption capacity and low in desorption temperature and causes little corrosion to equipment. The novel absorbent can be widely applied to separation and purification of CO2 in natural gas, transformation gas, flue gas and synthesized gas.

Description

technical field [0001] The invention belongs to the technical field of gas capture, separation and purification of petroleum, chemical industry, materials, etc., and specifically relates to a method for capturing or separating carbon dioxide (CO2) from a gas mixture. 2 ) of the absorbing solvent. Background technique [0002] At present, for CO in mixed gases such as flue gas, natural gas, shift gas and syngas 2 The capture and separation method of the chemical absorption method is one of the most practical, mature and widely used technologies in various decarbonization processes, and the core of the chemical absorption method to capture carbon dioxide is the development of high-efficiency absorbents. Existing absorbents mainly include solvents such as monoethanolamine (MEA), diethanolamine (DEA), N-methyldiethanolamine (MDEA), diisopropanolamine (DIPA) or their mixed systems. One of the ideas for research on mixed amine absorbents is to form a mixed system by mixing a cer...

AI Technical Summary

Problems solved by technology

[0003] From the analysis of the characteristics of absorbent research at home and abroad, the commercial monoethanolamine absorption system has not yet solved a series of problems such as solvent degradation, equipment corrosion, and high desorption energy consumption; Coal power plants, industrial pit gas and other flue gas properties, the existing decarbonization solvents are characterized by fast absorption rate, but low absorption capacity, such as MEA absorbent process; or some absorbents have large absorption capacity, but slow absorption rate, such as MDEA absorbent process

At the same time, the existing solvents still have technical problems such as solvent degradation, high regeneration energy consumption, and equipment corrosion.

Images