Study On High-efficiency Combustion And Pollutant Emission Of Biomass Under O₂/CO₂ Atmosphere

As the greenhouse effect becomes more apparent,carbon dioxide emissions have begun to receive widespread attention.Carbon capture of fossil fuel combustion flue gas can reduce carbon dioxide emissions to the atmosphere,but it cannot reduce the carbon dioxide concentration in the existing atmosphere.Biomass absorbs carbon dioxide in the atmosphere through photosynthesis.Combining biomass oxy-fuel combustion technology with carbon capture technology is an effective way to reduce the concentration of carbon dioxide in the atmosphere.However,how to achieve high-efficiency combustion and low-pollution emissions in this process is of great significance for the safe operation of carbon capture systems and the effective utilization of biomass energy.In this paper,a biomass oxy-fuel combustion water heater with recycled flue gas at rated power of 18kW（biomass pellets consumption at 3.5kg/h）was built.The concentration of oxygen,excess oxygen,and circulating flue gas were studied experimentally.The impact of the material’s efficient combustion and pollutant emissions.Based on the above theories,the oxy-fuel combustion system of biomass was designed and modified,and a complete set of flue gas circulation system was designed.The oxygen concentration,excess oxygen coefficient,and circulating flue gas volume were used to study the efficient combustion and pollutant emissions of biomass through experiments.The experimental results show that the increase of oxygen concentration can reduce the flue gas temperature of the boiler and effectively increase the overall efficiency of the biomass furnace and the furnace temperature,and will slightly increase the emission of NO,but will reduce the CO content in the flue gas.The increase of the excess oxygen coefficient will increase the furnace temperature and flue gas temperature of the furnace,but the overall efficiency of the boiler will be reduced due to the increase of the flue gas temperature.Excess oxygen coefficient will also increase NO emissions,but it will have a significant effect on CO emissions reduction.Under the O₂/RFG atmosphere,the furnace temperature and flue gas temperature are the lowest.The flue gas contains less NO and more CO,and the overall efficiency of the boiler is lower than the other two atmospheres.In addition,the Aspen Plus was used to simulate the oxy-fuel combustion process with recycled flue gas of biomass,and the effects of atmosphere,oxygen concentration,excess oxygen coefficient,and flue gas circulation volume on the pollutant emissions of biomass combustion were obtained.The trend of experimental results is basically the same,further verifying the experimental results.