Professor Minkee Choi’s team from the KAIST Department of Chemical and Biomolecular Engineering have developed a new high-performance carbon-dioxide absorbent. His team has also succeeded in synthesizing moderate volumes of this new adsorbent, indicating that, unlike previous adsorbents, it is scalable and will mostly likely be commercialized industry. Their research was published online in the August 30 edition of the journal Nature Communications.
Carbon-dioxide capture methods have been considered as a short-term solution to curbing carbon emissions stemming from the use of fossil fuels. There have been extensive research on post-combustion carbon dioxide capture methods, especially on those via amine-based adsorbents; such technology can readily be retrofitted to existing power plants, one of the main sources of carbon emissions around the world.
However, earlier research have largely focused on the capture capacity of adsorbents over their carbon separation and adsorbent regeneration abilities. As a result, most of these adsorbents have displayed volatile amine loss, longevity issues, and energy-consuming regeneration, rendering them virtually infeasible for mass adoption in industry.
Professor Choi opted for solid adsorbents, which have been noted for non-corrosiveness and potential energy efficiency during regeneration. By embedding polyethyleneimine (PEI), a type of amine, into the large-porosity supports of silica microspheres the team synthesized a PEI - silica composite, which exhibited significant improvement across all performance measures - desorption abilities, regeneration stability - while still maintaining the large working capacity (capturing abilities) typically exhibited by regular amine-based adsorbents. In fact, the team’s new adsorbent displayed adsorbent stability over multiple consecutive adsorption cycles.
The new adsorbent is also versatile and scalable unlike existing versions, whose synthesis involved the use of expensive and corrosive chemicals. The use of silica and PEI along with a practical regeneration method means that Professor Choi’s adsorbent is much closer to commercialization than are its counterparts.