Experimental screening of oxygen carrier for a pressurized chemical looping combustion

Chemical looping combustion (CLC), an oxy-combustion CO2 capture process, is a promising technology with great potential to reduce the CO2 separation cost and increase the power generation efficiency. The overall efficiency can be determined by the appropriate employment of oxygen carriers, playing a significant role in the economic penalties. In this study, a suitable oxygen carrier for a pressurized CLC was successively and systematically identified from seven types of oxygen carriers. OCN703 and N002-R1, with an adequate solid conversion rate but low durability, were excluded from the candidates by the thermogravimetric analysis results and attrition indices. From the atmospheric fluidized bed, the fuel conversion and CO2 selectivity of LOC023, LOC031, and LOC032 were found to be lower than that of OCN717 and N016-R4. From the semi-continuous fluidized bed, it was inferred that N016-R4 can achieve high CO2 selectivity with a low solid circulation rate when compared to OCN717. To conclude, N016-R4 was identified as the optimal oxygen carrier for a pressurized CLC. The experimental screening process and the criteria to identify the optimal oxygen carrier used in this study are expected to be applicable to new oxygen carriers that will be developed in the future.