Design and Energy Analysis of Solid Oxide Fuel Cell and Gas Turbine Hybrid Systems with Membrane Reactor

The methanol-reforming solid oxide fuel cell (SOFC) emits high concentration of CO2 from the anode outlet. To achieve the goal of clean and low-carbon power generation, a CO2 capture unit is integrated with SOFC. In this work, the CO2 capture unit were set at different places in the conventional SOFC and gas turbine (GT) hybrid system. One was to place the water-gas-shift membrane reactor (WGSMR) at the anode inlet (SOFC-MRpre) and the other at the anode outlet (SOFC-MRpost). The key parameters, including the anode off-gas recycling ratio (RR), steam-to-carbon ratio (S/C), and operating pressure, have been investigated. Besides, the effects of the parameters on the power production, electrical efficiency, system efficiency, and CO2 capture capacity of the two processes were analyzed. It was found that the electrical and system efficiencies reached 53.3% and 41.8% for the SOFC-MRpre process, while 62.0% and 60.4% for the SOFC-MRpost process, respectively. The results show that placing the membrane reactor at the anode outlet can significantly reduce the energy consumption of the vacuum and blower, thus increasing the system efficiency. Besides, near-zero carbon emissions with only a 7.3% energy penalty can be achieved by the SOFC-MRpost process. These results reveal that the SOFC-MRpost process has more advantages than the SOFC-MRpre process.