Experimental study on the combustion characteristics of an asymmetric swirling flameless combustor using biogas

This work investigated temperature field, temperature uniformity, thermal efficiency, and pollutant emission of an asymmetric swirling combustor operating with different biogas compositions under various configurations to determine the optimum condition for operating and utilizing the combustor. From the results obtained from the combustor, configuration FATB10812 (10 axial air-ports, 8 tangential air-ports, and 12 fuel ports) gave better temperature uniformity, higher efficiency, and lower pollutant emission compared to other configurations due to the broader circumferential injection points in the configuration. Also, 75% methane composition gave a better performance of the combustor due to a moderate level of temperature, which suppresses the formation of both CO and NOx emissions, even though 90% methane composition gave efficiency, which is slightly higher than 75% with 2%, due to the presence of 25% of incombustible CO2 in 75% methane composition. Therefore, the optimum condition proposed from this work is configuration FATB10812 operating with biogas of 75% methane composition biogas.