Characteristics of methane combustion using H2 injection in a turbulent fluidized bed of inert particles

The characteristics of methane combustion were investigated in a fluidized bed reactor containing inert SiO2 particles in the temperature range 700-800 degrees C. In particular, the methane was combusted using H-2 injection as an ignition source to initiate combustion at the relatively low temperature of 700 degrees C. It was found that complete combustion can be achieved at a bed temperature above 870 degrees C without ignition and at 800 degrees C with ignition. Even though the fast gaseous combustion of methane was initiated by ignition, the fast chain reaction was quenched under the condition of a bed temperature of less than 800 degrees C and insufficient residence time compared with the ignition delay at a given bed temperature. Moreover, it was confirmed that whereas NOx emission is reduced by decreasing the combustion temperature, the CO concentration of the exhaust gases increases drastically. (C) 2021 Elsevier Ltd. All rights reserved.