An LCA and energy analysis of a biomass integrated-pyrolysis gasification/SOFC system with H₂S removal

Fuel cell power systems are considered attractive for their potential for mitigating climate change. Here, the fuel is assumed to be synthesized through an indirect pyrolysis gasification process, and the integrated gasification SOFC system is considered in this study. In the performance of SOFC, the impurities (e.g., H₂S) in a fuel affect the system, i.e., the voltage of a cell drops. Regarding the removal of impurities, conditions besides the species of adsorbent, like temperature and pressure, must be considered. Therefore, we compared the following two adsorbents in terms of the operational and environmental performances: non-recyclable CeO₂ (high temperature) and recyclable Hydroxyl Aluminum Silicate Clay (HAS-Clay) (low temperature). Moreover, we estimated energy and exergy efficiencies, and life cycle assessment impacts on both adsorbents. The total exergy efficiencies were 35.6 % for CeO₂ and 33.0 % for HAS-Clay. This implies that 19 recycling cycles with the use of HAS-Clay are necessary to obtain the advantage for the CeO2 case in terms of abiotic depletion potential which is one of the impact categories.