Atkinson cycle CFD CeO2 doping GRI-Mech 3.0 Lewis number MP-PIC method NO emissions PIV activated carbon sorbent air-pollution control battery recycling bioethanol biofuel burner chemical analysis cleaner combustion climate change combustion combustion adjustment computational fluid dynamics control system efficiency cooking stove density functional theory(DFT) calculations ecological fuels emission characteristics energy management field study flaring angle flue gas mercury removal fluidized bed fuel rich/lean combustion