Flue gas cleanup with hydroxyl radical reactions

Abstract
Electric discharge processes have been intensively tested for application to flue gas cleanup. Among the several means of OH- radical generation grouped as electric discharge, E-Beam irradiation is the one that has been most thoroughly studied. Corona glow discharge, especially pulsed corona glow discharge, on the other hand, has attracted attention recently, and several active research projects are being conducted in the United States, Japan, West Germany, and Italy. Other promising approaches for generating OH radicals efficiently are based on thermal or catalytic decomposition of OH-radical precursors. If mixing problems can be overcome to achieve homogeneous distribution of OH radicals in the flue gas stream, these methods may be applicable to flue gas cleanup. Because of their high OH-radical generation rates and potentially low capital costs, the following three approaches are recommended to be tested for their potential capability to remove SO{sub 2}/NO{sub x}: (1) H{sub 2}/O{sub 2} combustion in a hydrogen torch, (2) thermal decomposition of H{sub 2}O{sub 2}, and (3) catalytic decomposition of H{sub 2}O. Ideally, the OH radicals will convert SO{sub 2} and NO{sub x} to sulfuric acid and nitric acid. These acids or acid precursors would easily be removed from the flue gas by conventional technology,more » such as spray drying and wet limestone scrubbing. 67 refs., 2 tabs. « less