REMOVAL OF NITRIC-OXIDE BY ITS REDUCTION WITH HYDROCARBONS OVER ALUMINA UNDER LEAN CONDITIONS

The objective of this; study is to investigate the removal of nitric oxide (NO) from a net oxidizing gas mixture using hydrocarbons (HC) as reductants over alumina. Studies were conducted to investigate the effect of operating variables such as catalyst temperature, space velocity, and HC concentration on NO conversion. The durability of the catalyst was also investigated. Propane (C3H8) and propylene (C3H6) were used as reductants during the flow reactor experiments, The study shows that the removal of NO over Al2O3 occurs in the 500-700-degrees-C temperature range when either C3H6 or C3H8 is used as reductant. Maximum NO conversion is observed around 600-degrees-C. The NO conversions observed using C3H8 and C3H6 are comparable when NO is being removed from a NO-HC-O2-SO2-CO-H-2-H2O stream at space velocities lower than 38570 h-1. At space velocities higher than 38 570 h-1, higher NO conversion is observed when C3H6 is used as reductant. Durability investigations conducted on the pulse flame combustor show that the durability of Al2O3 is better than that of the zeolite-based catalysts for removing NO under oxidizing conditions.