Experimental research on oxygenenriched combustion at 100 kWth pressurized circulating fluidized bed

The pressurized circulating fluidized bed oxygenenriched combustion technology (PCFBOFC) is a new type of clean and efficient combustion technology. Its high carbon capture rate and low energy consumption make it attract wide attention and have a good development potential and industrial application prospects. However, due to problems caused by the increase in combustion pressure, the existing research on pressurized circulating fluidized bed oxygenenriched combustion focuses more on theoretical modeling, or experiments and mechanisms based on small experimental benches. Southeast University has developed a hotstate experimental device for pressurized circulating fluidized bed oxyfuel combustion with a heat input power of 100 kW, realized the largescale demonstration of pressurized circulating fluidized bed oxyfuel combustion, and obtained some thermal experimental data and design and operation experience. The experimental results show that the device can realize the smooth switching of the two combustion modes, the PCFB can operate stably at a pressure of 0.6 MPa, the temperature in the furnace changes smoothly, and dry flue gas CO2 concentration stabilizes above 90% in the POFC mode, achieving the expected design goal.The increase in combustion pressure accelerates the chemical reaction rate and prolongs the gas residence time, causes more fuelN to be converted into nitrogen combined with the twostage air distribution mode, and finally shows that the increase in pressure significantly reduces the emission concentration of NO and N2O in the exhaust gas.In addition, the increase in pressure improves the combustion efficiency, significantly reduces the concentration of CO and CH4 in the flue gas, and reaches lower concentrations at 0.4 MPa and 0.2 MPa, respectively.