Catalytic removal of NO and PAHs over AC-supported catalysts from incineration flue gas: Bench-scale and pilot-plant tests

Abstract

For dioxin removal from incineration flue gas, the common method is absorption using activated carbon (AC). In order to reduce the consumption of energy, it is worth to evaluate the destruction removal efficiency (DRE) of NO and polycyclic aromatic hydrocarbons (PAHs) over AC with a few metals loading while dioxin is physical absorbed by AC. As a result, in the present work, the use of AC as a catalyst support for simultaneous NO reduction and PAHs catalytic oxidation was investigated as an alternative technology to improve incinerator processes. This study examined the selective removal of NO and PAHs from incineration flue gas containing O2, N2, CO2, H2O, NO, organic compounds and fly ash over M/AC catalysts (M = Fe, Co, Ni, and Cu) using bench-scale and pilot-plant tests. Investigations on the effects of the incineration flue gas composition and the structure of the metal active site on NO and PAHs conversion revealed that the conversion activity increases as the atomic number of the transition metals increase, except for Ni. Carbon monoxide can act as a reductant to increase the NO removal efficiency. The M/AC catalysts showed high reactivity for simultaneous PAHs oxidation and NO reduction. The results provide useful information for the design and application of AC injection or selective catalyst reduction systems for waste incineration plants.