Multi-objective optimization of a clean combined system based gasifier-solid oxide fuel cell

Abstract

Biomass can be used as fuel of fuel cells by conducting thermochemical process such as biomass gasification. In this study, the required fuel of a solid oxide fuel cell was supplied through pine gasification in a gasifier reactor. The purpose of this study was provided an appropriate configuration to a co-generation system produced heat and power and the state with maximum heat and power production and minimum carbon dioxide emission was obtained. The outputs were power, heat, and CO2 emission investigated with respect to steam to biomass ratio of gasification and current density and fuel utilization factor of solid oxide fuel cell. The results indicated that fuel utilization factor contributed the most on power and hot water with shares of 73.64% and 47.27%, respectively. However, current density had the highest influence on carbon dioxide emission with a share of 83.41%. Parametric analysis illustrated that increasing fuel utilization factor remarkably enhanced the power production and mitigated hot water production. A considerable reduction was observed in carbon dioxide emission by increasing current density. Single-objective and multi-objective optimizations revealed that steam to biomass ratio of 2, 4600 A/m2 of current density, 0.77 of utilization factor are the optimum states. Power production of 196.8 kW, hot water production of 1203 g/s, and carbon dioxide emission of 1261 kg/MW.h were the outputs of the optimum state.