Volume 60, Issue 2 p. 673-689
Separations: Materials, Devices, and Processes

The role of water on postcombustion CO2 capture by vacuum swing adsorption: Bed layering and purge to feed ratio

Gang Li

Gang Li

Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC), Dept. of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, VIC, 3010 Australia

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Penny Xiao

Penny Xiao

Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC), Dept. of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, VIC, 3010 Australia

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Jun Zhang

Jun Zhang

Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC), Dept. of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, VIC, 3010 Australia

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Paul A. Webley

Corresponding Author

Paul A. Webley

Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC), Dept. of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, VIC, 3010 Australia

Correspondence concerning this article should be addressed to P. Webley at [email protected].Search for more papers by this author
Dong Xu

Dong Xu

Energy Innovation Technology Research Center, 2 Street, Future Science & Technology Park North, Changping District, Beijing, 102209 China

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First published: 31 October 2013
Citations: 52

Abstract

The influence of water vapor on the adsorption of CO2 in carbon capture by vacuum swing adsorption (VSA) was described. VSA experiments with single and multilayered columns using alumina and zeolite 13X were conducted to understand the migration of water. The penetration depth of water in the column could be controlled by maintaining the purge-to-feed ratio above a critical value. At high water content in the feed (>4%), employment of a water adsorbing prelayer was essential to prevent failure of the carbon capture process. A simple axial working capacity model predicts the penetration depth of water in the column for a given feed temperature and adsorption isotherm, and the layering ratio can be selected accordingly. Although water is detrimental to CO2 capture with polar adsorbents, long-term recovery of CO2 is still possible by appropriate layering and ensuring an adequate purge-to-feed ratio. © 2013 American Institute of Chemical Engineers AIChE J 60: 673–689, 2014