Acid Gas Removal Characteristics of Corona Discharge Methane Radical Shower-Catalyst Hybrid System for Treatment of Jet Engine Test Cell Flue Gas 1999-01-3634

Acid gas removal experiments are carried out in a large bench scale corona radical shower reactor-catalyst hybrid system. A simulated stationary jet engine test cell flue gas is air mixed with NO, SO₂ and CH₄. NO, NO₂ and SO₂ concentrations were measured by a Green Line gas analyzer and the trace by-products are determined by Fourier Transform Infra-Red spectroscopy (FTIR). The aerosol particles generated by the acid gases and methane related plasma processes were collected by the electrostatic precipitator operated at !19 kV dc downstream of the reactor. The size of the reactor is (10×30×100 cm) and four pipe with nozzle type radical injectors are placed in series. The corona radical shower electrode used was a 6 mm o.d. tube equipped with 28 hollow electrodes (1.2 mm i.d./1.5 mm o.d.). Additional gas consisting of an air-CH₄ mixture was injected from these hollow electrodes to the reactor via the corona discharge generated by a positive dc high voltage at the edge of the hollow electrodes. Catalyst is placed 20 cm downstream of corona shower reactor and may be electrically heated by heating tapes. The results show that both the removal efficiencies of NO and SO₂ increase with increasing applied voltage. It is also shown that high concentrations of hydrocarbon in flue gas have a negative effect on NO removal, where part of the NO is converted only to NO₂ but not to ammonium nitrate aerosol particles or reductions to N₂ and H₂O. The effect of catalytic reactions is significant with CH₄ injections without catalyst heating for NO_x and SO₂ removals. However, SO₂ removal efficiently is degraded by catalyst heating.