Core-shell magnetic ZIF-8@Fe3O4-carbonic anhydrase biocatalyst for promoting CO2 absorption into MDEA solution

Abstract

Tertiary amine-based absorption process possesses high absorption capacity and low heat duty for CO2 capture. However, its slow CO2 absorption rate retards its industrial application. This work developed a core-shell magnetic ZIF-8@Fe3O4-carbonic anhydrase composite to promote CO2 absorption into tertiary amine, e.g., diethanolamine (MDEA) due to its easy recovery from the solution. The catalytic performance of CA@ZIF-8@Fe3O4 that had three particle sizes were investigated. Experimental results revealed that the obtained CA@ZIF-8@Fe3O4 can achieve the relative activity as high as 95.2 % compared with the free counterparts. Large particle size of ZIF-8@Fe3O4 was beneficial to activity but adverse to loading. Magnetic analysis shows that the developed CA@ZIF-8@Fe3O4 possessed remarkable magnetic response which made recycling more convenient.