Study on MCFC-integrated GSCC systems with SEGR in parallel or series and CO2 capture

• Published in: Frontiers in energy research Vol. 11
• Main Authors: Bian, Jing, Duan, Liqiang
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 14-11-2023
• Subjects: CO2 emissions; economic analysis; gas turbine; molten carbonate fuel cell; selective exhaust gas recirculation
• ISSN: 2296-598X; 2296-598X
• DOI: 10.3389/fenrg.2023.1256000

In this paper, two new molten carbonate fuel cell (MCFC)-integrated gas–steam combined cycle (GSCC) systems with selective exhaust gas recirculation (SEGR) and CO
2
capture are proposed and analyzed. The CO
2
concentration in the gas turbine emission is increased because CO
2
is selectively recycled with the help of SEGR. Molten carbonate fuel cells (MCFCs) are another way to increase CO
2
concentration in the gas turbine flue gas by translating only CO
2
from the cathode to the anode. In these two new gas–steam combined cycle systems, SEGR connected with MCFC, either in parallel or series, increases CO
2
concentration beyond 11%. A gas–steam combined cycle system combined with MCFC and CO
2
capture without SEGR is used as the reference system. Aspen Plus software is adopted to build the system models, and the performances of different systems are discussed and compared. The research results reveal that for the MCFC-integrated gas–steam combined cycle system with SEGR in series and CO
2
capture, the CO
2
concentration of gas turbine exhaust increases to 11.72% and the thermal efficiency is 56.29% when the overall CO
2
capture rate is 88.16%, which is 1.13% higher than that of the reference system; for the MCFC-integrated gas–steam combined cycle system with SEGR in parallel and CO
2
capture, the CO
2
concentration of gas turbine exhaust increases to 14.15% and the thermal efficiency is 56.62%, which is 1.46% higher than that of the reference system. Furthermore, the economic analysis results show that the economic performances of new systems are mainly influenced by MCFC cost and will be gradually improved with the decrease in the MCFC cost.