Microwave calcination of waste oyster shells for CO2 capture

Abstract

Waste oyster shells can be used as a source of sorbent to capture CO2 because of its high Ca content. In this study, microwave calcination of waste oyster shells was carried and compared with conventional calcination. The feedstock was successfully heated under microwave irradiation. Both maximum temperature and heating rate increased with increasing microwave power level. The mass loss of microwave calcination of waste oyster shells was 40.64%, a little higher than the maximum theoretical mass loss of waste oyster shells calcination. Compared with conventional calcination, microwave calcination would need lower energy input and lower rank of heat resistance required for the thermal apparatus. The first CaO conversion of the sorbent produced by microwave calcination was 33.47%, higher than that of the sorbent produced by conventional calcination, 26.44%. The sorbent produced by microwave calcination would have better durability than that produced by conventional heating. Therefore, microwave calcination should be a promising technique to recover waste oyster shells or other Ca-rich materials for CO2 capture.