Abstract
A proton exchange membrane fuel cell (PEMFC) has received considerable attention as an alternative power generation device. Using biomass to produce hydrogen via a gasification process makes the integrated system of the PEMFC and biomass gasification a potential power production technology. In this study, the performance of the biomass gasification and PEMFC system is theoretically analyzed. Two important operational issues of the system, i.e., waste heat recovery and response to variation in power-to-heat ratio, are considered. The capacity of the PEMFC system is selected to cover a daily residential power demand of 100 kW. In the proposed system, useful heat from the biomass processing and PEMFC is recovered for use in space heat or water heating in household. The simulation result shows that the PEMFC stack efficiency of the proposed system is around 47 to 57 %. The efficiency of the combined heat and power system is in range of 68 to 93 %, which is based on biomass input energy and recovered heat from the exhaust gas released from an afterburner. In addition, it is found that a regulation of the flow rate of biomass to the gasifier and afterburner is a key parameter in the PEMFC-based system to achieve the system requirement when the power-to-heat ratio is changed. The result indicates that the power-to-heat ratio of the designed system varies from 0.06 to 0.75.
