Thermo-Economic analysis of a novel biomass Gasification-Based power system integrated with a supercritical CO2 cycle and a Coal-Fired power plant

Abstract

The integration of biomass gasification-based power generation, supercritical CO2 power cycle, and coal-fired power generation was implemented to improve biomass utilization. The clean syngas harvested from biomass gasification is exploited by a gas turbine and then the resulting hot exhaust is used to heat the CO2 stream of the supercritical CO2 cycle and the feedwater streams of the coal power plant. The raw syngas cooling is accomplished by delivering thermal energy to the CO2 and feedwater as well. As the biomass energy is sufficiently exploited through the supercritical CO2 cycle and coal power cycle, high biomass-to-electricity efficiency can be expected. Thermodynamic and economic analysis was conducted to examine the performance of the novel scheme, based on a 2.22 kg/s biomass gasifier and 350 MW coal power plant. The results indicated that the energy efficiency and exergy efficiency of biomass-to-electricity can attain 43.98% and 40.58% respectively at the design point, while the net power generated from coal remains constant. Only 1.07 years (irrespective of the construction period) are needed to recoup the initial investment of the biomass gasification-based power project considering discounts, and the net present value reaches 31,358.34 k$. Hence, the new design is advantageous and favorable in the field of biomass utilization.