Modeling and Simulation of Biomass Gasification Integrated with Solid Oxide Fuel Cell System for Power Generation /

Abstract

In order to supply the electricity in off-grid rural areas, on-site energy generation technologies need to be developed. For this purpose, a detailed model of downdraft biomass gasifier integrated with Solid Oxide fuel cell(SOFC) the system was made and simulated to produce power of 120 kW. Aspen Plus software was used to model the system. It has inbuilt unit operation blocks which were used to model different stages and components of gasifier and fuel cell. Fortran coding was done to model different design specifications as well as power calculations. Gasifier produces a syngas which is used as a fuel for SOFC. SOFC then converts the chemical energy stored in fuel to electrical energy. Stack voltage is then calculated using the Nernst Voltage. Voltage losses were also calculated and subtracted from the Ideal Voltage. Both the models for gasifier and SOFC were validated using the data from the literature. Our models produced results very familiar with the results from the literature. Sensitivity analysis was done of following operating parameters for gasifier to check their effect on syngas composition and efficiency; gasification temperature, moisture content, and equivalence ratio. For SOFC sensitivity analysis was also done to check the effect of varying different parameters on Cell Voltage, Power output, Current density and efficiency of the system. Biomass flowrate, air utilization factor, and fuel utilization factor were the parameters analyzed. In order to check the performance of gasifier, cold gas efficiency and Low Heating Value of produced syngas were calculated. For SOFC’s performance measurement, its gross, as well as net efficiencies, were calculated.