Study on a new reed-coal coupled power generation system in Wuliangsuhai Lake wetland —Life cycle assessment and economic and technical analysis

Abstract

As a major hydrophyte in wetlands, reeds purify water by reducing water eutrophication and have high value-added potential as biomass fuel for power generation. Based on pyrolysis experiments, reed has the maximum bio-oil yield of 57.11% at 550 °C. In this study, the optimal temperature conditions were used for the pyrolysis of reeds coupled with thermal power generation (BP-TPG). The BP-TPG process is relatively independent and avoids the deposition of alkali metals from biomass on the surface of the steam generator directly. The BP-TPG and biomass gasification coupled thermal power Generation (BG-TPG) were further investigated by process simulation and life cycle assessment. The GWP values of BP-TPG systems could be reduced by at least 4.8% than that of TPG. As the growth of reeds absorbed total nitrogen (TN) and total phosphorus (TP) from the wetland water, the eutrophication potential was reduced by 0.333 kg PO4/MWh less than that of the use of corn straw feedstocks. Economic and technical analysis showed that the BP-TPG-G system had the lowest cost of electricity generation at 386 ¥/MWh. Sensitivity analysis showed that the impact of coal prices on power generation costs cannot be ignored.