Effect of combustion gas components on electrochemically promoted CO2 capture performance of Pt/K-βAl2O3 at bench scale

Abstract Due to the continuous increase in CO 2 atmospheric levels resulting from fossil fuels combustion, it is necessary to develop new, more efficient and less-energy intensive processes, that allow economically and selectively separate CO 2 without the negative impact of co-existing gases (H 2 O, SO 2 , NO, etc.). This work presents a bench-scale study of the effect of combustion gas components on the electropromoted CO 2 capture performance of an easily scalable Pt/K-βAl 2 O 3 tubular electrochemical system, at high flow rates and in the presence of representative amounts of O 2 , H 2 O, SO 2 , NO and N 2 O. On the basis of previous mechanistic and spectroscopic studies, cyclic voltammetry studies showed that the system is able to capture CO 2 , not only by electropromoted adsorption but also as carbonates/bicarbonates by potassium ions electrochemically supplied to Pt surface. CO 2 capture is enhanced in the presence of O 2 and H 2 O. The CO 2 capture behaviour of the system is almost unaffected by the presence of N 2 O. SO 2 poisons CO 2 capture, whereas the presence of NO appears to considerably hinder CO 2 capture. The Pt/K-βAl 2 O 3 system can be regenerated, allowing CO 2 separation, by electrochemical decomposition of previously stored compounds without increasing temperature, with the consequent energy saving.