Research progress on biomass oxy-fuel combustion technology

ZHANG Zewu; MAO Wenchao; LE Xiaoyu; DONG Xiaoteng; LUO Cong; ZHANG Liqi

doi:10.13226/j.issn.1006-6772.JJMJS25120801

Abstract：Bio-Energy Carbon Capture Utilization and Storage(BECCUS)has been proposed as a negative carbon technology,which combines the biomass combustion with CCUS techniques to achieve rapid,large-scale,and sustainable CO2 reduction.Biomass oxy-fuel combustion technology replaces the fuel in oxy-fuel combustion with a mixture of biomass and coal or pure biomass,and adopts high-purity oxygen and recirculated flue gas as the oxidizer,so that it can achieve high CO2 concentration in the flue gas.Compared with conventional pulverized coal oxy-fuel combustion and biomass air combustion,due to significant changes in fuel and combustion atmosphere,the furnace temperature and heat flux,pollutant emissions,heating surface issues,CO2 capture efficiency,and power plant efficiency in biomass oxy-fuel combustion also undergo noticeable changes.In this regard,based on previous research,this article systematically reviews the latest research progress in biomass oxy-fuel combustion technology,summarizes the combustion characteristics and pollutant formation mechanisms of biomass oxy-fuel combustion:the reaction kinetics parameters of biomass oxy-fuel combustion remain largely consistent under both air-and oxy-fuel atmospheres;the gasification reactions of biomass char with CO2 and H2O help reduce NOx formation and promote coal char burnout,generating more fine particulate matter;the initial oxygen concentration required for biomass oxy-fuel combustion to match air combustion exceeds 30％.The article also points out the challenges faced by biomass oxy-fuel combustion,such as fuel instability,high costs,heating surface corrosion,and pollutant formation.To address these issues,it proposes researching the synergistic effects of co-firing multiple biomass types on combustion characteristics(i.e.,ignition,burnout)and pollutants formation(i.e.,NOx,SO2,HCl),forming new insights to enhance combustion and suppress pollutant generation;optimizing operational parameters of biomass oxy-fuel combustion and regulating furnace temperature to mitigate ash deposition,slagging,and corrosion;adopting emerging technologies such as pressurized oxy-fuel combustion and pressurized circulating fluidized bed oxy-fuel combustion to improve combustion efficiency and reduce pollutant emissions;and designing new multi-generation processes for electricity-heat-gas production based on biomass oxy-fuel combustion to achieve autonomous regulation of multi-objective products and adapt to diverse application scenarios.Ultimately,this provides a theoretical basis and important reference for achieving low-carbon and clean combustion of biomass.