Unlocking the techno-economic potential of biomass gasification for power generation: Comparative analysis across diverse plant capacities

This research aims to evaluate the techno-economic viability and commercial potential of biomass gasification across different capacities. Sensitivity analysis was conducted based on an established downdraft gasifier model using Aspen Plus. Results underscored the significant impact of gasification temperature and equivalence ratio (ER) on syngas composition, low heating value (LHV), and cold gas efficiency (CGE). Among the feedstocks tested, coconut shell emerged as a feasible feedstock, yielding syngas with an LHV of 8.93 MJ/Nm³ and achieving a CGE of up to 71.12 %. Optimal gasification temperatures ranged between 750 °C to 1,000 °C, with peak ER falling within 0.1 to 0.3. Economic analysis revealed that smaller-scale operations like Plant A resulted in a negative net present value of - US$0.63 million, indicating unfavorable investments. The internal rate of return notably increased from 9.53 % for Plant B compared to -2.56 % for Plant A (20 kW). Plant D, with larger capacity of 20 MW, showed an impressive payback period of less than two years (1.69 years). Medium to large-scale plants such as Plant C (2 MW) and Plant D demonstrated greater economic resilience, with Plant D achieving a significantly lower levelized cost of electricity of US$ 0.19/kWh compared to Plant A at US$ 0.86/kWh. It was noted that the impact of capital costs, operating expenses, and revenue variations is less pronounced at larger scales. The findings from this study shed light on the feasibility of biomass gasification for power generation as a viable option, thereby unlocking the potential for its large-scale commercialization.