Influence of addition of functionalized alumina particles on CO2 stripping from amine solvents

摘要

Thermal energy required for regeneration of an absorbent liquid in a chemical absorption method employed in CCS needs to be reduced to make CCS technology feasible. In order to promote CO2 desorption from the rich absorbent solution at lower temperature compared with the conventional regeneration method using steam, influence of addition of α-alumina particles to a rich diethanolamine (DEA) aqueous solution on CO2 desorption from it was investigated at 40 °C. Also, the a-alumina particles were functionalized with phosphate groups or amino groups and their influence on CO2 desorption was investigated. The results showed that the addition of the alumina particles with and without surface functionalization promoted CO2 desorption. The isoelectric point for the untreated alumina particles and the alumina particles functionalized with phosphate groups and amino groups was at pH 7.2, pH 4.0 and pH 9.5, respectively. The alumina particles functionalized with phosphate groups promoted CO2 desorption most remarkably among them while the alumina particles functionalized with amino groups slightly suppress CO2 desorption compared with the untreated alumina particles. It has been revealed that introduction of acidic functional groups to the surface of solid particle is an effective way for promoting CO2 desorption from amine solvents.