Combustion of methane and propane in an incipiently fluidized bed

Temperature and gas concentration experiments have been conducted to determine the temperature at which volatiles begin to combust within the particulate phase of a bubbling fluidized bed. The particulate phase of such a bed was approximated by operating a fluidized bed at incipient fluidization. Gas concentration measurements were made from products of both premixed propane-air and premixed methane-air mixtures. The critical temperatures above which combustion products were observed in the particulate phase were 835°C and 915°C for propane and methane, respectively; below the critical temperature for each fuel-air mixture, combustion was negligible. The propane critical combustion temperature was confirmed from the results of unsteady-state temperature and ignition delay time measurements. These experiments demonstrate that the particulate phase can inhibit the oxidation rate of hydrocarbons.