Thermodynamic and exergoeconomic analysis of a proton exchange membrane fuel cell/absorption chiller CCHP system based on biomass gasification

Abstract

This work investigates an integrated system consisting of biomass gasification process, proton exchange membrane fuel cell (PEMFC) and absorption chiller. The proposed system is studied from the energetic and exergoeconomic point of view. In addition, parametric analysis and uncertainty analysis are carried out to investigate the effects of four key operational parameters and three uncertain parameters. System energy efficiency and exergy efficiency are obtained as 57.41% and 18.07%, respectively. 21.46% of the electricity production is consumed by auxiliary components of the PEMFC stack. Largest exergy destruction is in the gasifier and the stack, due to significant irreversibility of chemical/electrochemical reactions. Exergoeconomic results indicate that in the selective oxidation process, investment cost is much higher than the cost rate of exergy destruction. While gasifier, anode/cathode heat exchangers and humidifiers, condenser, solution heat exchangers and valves have poor exergetic performance. High current density, operation temperature and moisture content are unfavorable for exergy efficiency. Extension of operation life, lower interest rate and lower maintenance factor can guarantee a desired system exergoeconomic performance. This research provides pragmatic information about thermodynamic and exergoeconomic performance of this integrated system. Obtained results are important for system design and operational optimization on various PEMFC coupled polygeneration systems.