Thermo-economic and environmental performance analyses of a biomass-based carbon negative system integrating externally fired gas turbine and molten carbonate fuel cell

Abstract

Biomass fueled power generation systems integrated with carbon capture has very good potential of mitigating climate change, but they usually experience low efficiency. A novel biomass gasification-based carbon negative system consisting of an externally fired gas turbine, post combustion CO2 capture employing molten carbonate fuel cell (MCFC) and waste heat recovery through steam cycle and organic Rankine cycle (ORC) is proposed and investigated in this article. Energy, exergy, economy and environmental analyses of the proposed system have been performed. Parametric investigation has been carried out and the effects of key operating parameters i.e., compressor pressure ratio, turbine inlet temperature, current density and fuel utilization factor of the fuel cell, steam pressure of the steam cycle on the overall performance of the proposed plant have been observed. The proposed plant can generate 16.21 MW of maximum power, with 50.8% of maximum energy efficiency, costing minimum levelized electricity price (LEP) of 0.097 $/kWh with 90% carbon capture. Moreover, the plant captures yearly maximum 112,400 tons of carbon dioxide which results in 16.8 million $/year environmental benefit to the society. The results also show that the present system is superior in terms of both energy and economy aspects compared to the other biomass-based carbon negative systems with post combustion carbon capture mentioned in recent literature.