Absorption liquid for phase-change capturing of SO2

Abstract

The invention discloses an absorption liquid for phase-change capturing of SO2. The absorption liquid consists of an imidazole derivative and an organic solvent, wherein the mass percentage of the imidazole derivative is 20-30%. By adopting the absorption liquid, an effect of liquid-liquid or liquid-solid phase separation is achieved when SO2 is absorbed, the phase separation speed is rapid, the SO2 absorption load is high, and the content of SO2 of one of two phases can be up to 95% or greater; regeneration is achieved by only feeding an enriched liquid rich in SO2 into a regeneration tower, the treatment capacity of a solution in desorption is reduced, the desorption energy consumption is reduced, and an organic solvent in an upper phase can be recycled to absorb SO2 in a circulation manner. Therefore, the absorption liquid is a phase-change absorbent with excellent properties, has great energy-saving potential and is suitable for being used as a chemical absorbent for capturing SO2 in coal fume and the like.

Description

technical field [0001] The invention relates to SO in coal-fired flue gas 2 The capture, separation and recovery technology specifically relates to a new type of imidazole derivative phase-change absorption liquid, which belongs to the field of energy saving, emission reduction and gas purification. Background technique [0002] With the continuous acceleration of our country's industrialization process, the environmental quality is also deteriorating, and environmental problems have gradually become the focus of people's attention. In recent years, regional air pollution problems such as acid rain, haze and photochemical smog have become increasingly prominent in some areas of my country, seriously threatening public health and affecting environmental safety. SO 2 It is an important precursor for the formation of acid rain and haze. At present, my country's air pollution discharge load is huge, SO 2 Emissions rank first in the world, and air pollution is very serious. ...

AI Technical Summary

Problems solved by technology

However, the solute is volatile during the high-temperature desorption process and some thermally stable salts are generated, and the solvent loss is serious and the effective utilization rate is not high.

[0004] Bara reported the use of nitrogen atoms on weakly basic imidazole derivatives to absorb SO 2 Obtaining solid or liquid products, accompanied by the formation of absorption products, causes the viscosity of the absorption system to increase, hindering the progress of the absorption reaction, and the entire absorption system needs to be heated to the desorption temperature during desorption, and the regeneration energy consumption is high

Imidazole-based ionic liquids have high viscosity, which is not conducive to mass transfer, and the desorption conditions are harsh. It is difficult to completely desorb at high temperature, and the desorption energy consumption is high, which is not conducive to the regeneration and recycling of ionic liquids.