Techno-economic modeling of biomass gasification plants for small industries in Pakistan

This study presents a techno-economic assessment of biomass gasification plants for small and medium enterprises in Pakistan. The developed models are capable of assessing change in investment returns against variations in fuel type, sourcing radius, plant efficiency, and the plant capacity utilization. The case for a 100-kW plant with corn stover as the fuel, sourcing radius of 20 km, plant efficiency of 35%, and the capacity utilization factor for the first year of operation at 66% is presented. Total investment required for the plant is estimated to be US$56,882 with an IRR of 35.2%. Sensitivity analysis shows flexibility up to a sourcing radius of 27 km, plant efficiency of 27.5%, and capacity utilization of 55.6%. The study assesses investment outlays for 25 kW, 50 kW, 200 kW, 300 kW, and 500 kW as well. The plants achieve a breakeven at a maximum sourcing radius of 27 km at 36% plant efficiency or at a minimum plant efficiency of 27% at 18-km sourcing radius. Biomass fuel with the highest savings per kWh is estimated to be the corn stover whereas wheat straw offers the lowest savings. Unit electricity cost averages at US$0.12/kWh for externally sourced biomass and US$0.07/kWh for onsite biomass. The average required capital investment is estimated to be US$569/kW.