Regeneration of the catalysts on an SCR-plant behind oil-fired boilers

摘要

The catalysts serve for the reduction of the nitric oxides, where as a side reaction the oxidation of SO{sub}2 to SO{sub}3 takes place. During combustion with excess oxygen the vanadium contained in the heavy fuel oil forms vanadium pentoxide (V{sub}2O{sub}5) which effects an unwanted increase in the rate of conversion from SO{sub}2 into SO{sub}3 which also leads to corrosion problems in the downstream plant components. The rate of conversion of SO{sub}2 into SO{sub}3 increases with an increase in the thickness of the layer, thus the total amount of the vanadium pentoxide deposits.