A conceptual process design towards CO2 emission reduction by integration of solar-based hydrogen production and injection into biomass-derived solid oxide fuel cell

Abstract

Integration of biomass gasification with Solid Oxide Fuel Cell (SOFC) is a promising technology, particularly for small scale decentralized power systems. In this paper, to reduce the CO2 emission and biomass consumption of this system, it is incorporated with solar-based hydrogen production. The produced hydrogen is injected into the biomass gasification-SOFC system, proposing two different configurations. In the first configuration, the hydrogen is injected into the anode inlet (to provide a hydrogen rich fuel), while in the second proposed configuration it is injected into the afterburner of the SOFC (to increase the gas turbine inlet temperature). The two proposed configurations are comprehensively assessed and compared from thermodynamic, environmental and economic standpoints. In thermoeconomic analysis, the negative environmental damage costs of CO2 emission, as the primary greenhouse gas, is taken into account. Also, a parametric study is conducted to ascertain the major design variables after which tri-objective optimization is performed based on CO2 emission, levelized cost of electricity and exergy efficiency. The results indicated superior performance for the system with hydrogen injection into the anode compared to the injection into the afterburner. The former configuration has 20.6% higher exergy efficiency with 23.2% lower emission and 14.0% lower levelized electricity cost. For this configuration under the optimum operation, the exergy efficiency, CO2 emission and electricity cost are found to be 24.85%, 0.257 kg/kWh and 0.0911 $/kWh, respectively.