Abstract
An ion exchange membrane (IEM) loaded with CO32− ions was developed for reversible SO2 removal by humidity-swing based on the hydrolysis of CO32− and SO32− ions. The dry environment promotes the hydrolysis of CO32− in IEM to generate OH− which binds SO2 to form HSO3− and HCO3− that react with SO2 to form HSO3− and CO2. The absorbent can be regenerated with a HSO3−-to-SO32− transformation in a humid environment at room temperature. The SO32− ions in IEM are able to be hydrolyzed again into HSO3− ions and OH− ions for SO2 absorption when the surroundings are dry, and the absorbed SO2 will be released when wet. The transformation between SO32− ions and HSO3−/OH− ions driven by humidity-swing was verified by quantum chemical calculations. The SO2 absorption capacity of IEM reached 1.76 mmol/g. Besides, the effect of SO2 concentration on the desulfuration performance was experimentally studied and the results showed that the absorption rate and quantity increased significantly with the initial SO2 concentration ranging from 500 to 4000 ppm. The present work represents a new approach for SO2 removal and sheds light on more gas separation applications by humidityswing. Copyright © 2019 American Chemical Society.
Original language | English |
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Pages (from-to) | 10953-10958 |
Number of pages | 6 |
Journal | Energy & Fuels |
Volume | 33 |
Issue number | 11 |
Early online date | 30 Oct 2019 |
DOIs | |
Publication status | Published - 21 Nov 2019 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:Copyright © 2019 American Chemical Society.
Funding
The work was supported by Earth Engineering Center and Center for Advanced Materials for Energy and Environment at Columbia University. Support from the National key R&D program of China (2016YFE0102500) and the National Natural Science Foundation of China (11572238 and 11872302) is acknowledged. Y.L. acknowledges support from the National Key Research and Development Program of China (2016YFB0700300) and National Natural Science Foundation of China (11572239).