Techno-economic assessment of biomass and coal co-fueled chemical looping combustion unit integrated with supercritical CO2 cycle and Organic Rankine cycle

Abstract

This study evaluates the effect of co-combustion of woody biomass and coal on the techno-economic performance of a 300 MWth in-situ gasification chemical looping combustion power plant. The circulating fluidized bed reactor system was designed and a modified macroscopic model was applied to predict the fuel conversion and the CO2 capture efficiency. The supercritical CO2 cycle and the Organic Rankine cycle were integrated with the heat sources for power generation. The results showed that increasing biomass share in the input thermal power, in addition to enhancing the CO2 capture efficiency, improves the coal conversion. Moreover, negative CO2 emissions are achieved as the biomass share exceeds 50 MWth. The net electrical efficiency of the plant is about 43.89% and grows slightly for higher biomass shares. For biomass share of 150 MWth, the CO2 capture efficiency increases from 79.27% to 90.87%. Also, the levelized cost of electricity (LCOE) rises by 15.9%–108.262 $/MWh due to higher biomass price. Despite this increased fuel cost, the LCOE is still lower than that value for the coal-fired power plant with conventional CO2 capture technology. Biomass utilization becomes more cost-effective than coal if the carbon tax is above 30 $/tCO2.