Evaluation of carbon dioxide emission reduction in an energy cycle based on biomass gasification and molten carbonate fuel cell: exergoeconomic and environmental analyses

A competitive advantage for the molten carbonate fuel cell (MCFC)-driven energy processes is their fuel versatility. On the other hand, since MCFC consumes carbon dioxide, it can reduce the amount of carbon dioxide emissions compared with other fuel cells. Accordingly, the current paper develops and evaluates the thermodynamic, exergoeconomic and environmental analyses of a new hybrid energy process (HEP) based on a reformer MCFC stack and a biomass gasification process. A homogeneous ignition engine (HIE) and a heat recovery system are two other main units embedded in the developed HEP. In the developed cycle, MCFC and HIE produce electric energy, for which the required fuel is supplied through the obtained syngas from the biomass gasification process and the anode off-gas, respectively. The heat recovery system also leads to the establishment of the thermal balance of the energy cycle by recovering the thermal energies of the MCFC and HIE. The aim of the present work is to develop the multi-aspect evaluation of the proposed energy system toward a fruitful implementation feasibility analysis. The outcomes indicated that the rates of electrical and thermal powers obtained from the planned HEP were equal to nearly 1112 and 367 kW, respectively. Further, the calculated efficiencies for electric, gross power and total energy terms were equal to 51.5%, 55.7% and 69.9%, respectively. The developed HEP had 48% less carbon dioxide emissions compared with a petroleum-fired power plant, 15.8% less compared with a natural gas-fired plant and approximately 63% lower compared with a coal-fired power plant.