This paper reviews efforts to mitigate corrosion with pulp millvent odorous gases as they are conveyed to a boiler for thermal oxidation. These moisture laden gases emanate from a sulfite batch operated pulp milland are sent to a neighboring spent sulfite fueled boiler to comply with the 1990 Clean Air Act. Itwas recognized early during project definition that sulfuric acid dew point corrosion was a major concern withcarbon steel (CS) tubular air heaters. Corrosion studies were conducted in the field prior to and after project startup to determine if heat exchange surfaces were at risk of wastage. Various types of measurements were used such as polarization resistance, weight loss coupons , solution resistance, and electrical resistance to monitor corrosion of CS and 316L stainless steel (SS).
Keywords: sulfuric acid dew point corrosion, sulfite pulp mill, 1990 Clean AirAct, S02 vapor emissions, polarization resistance, electrical resistance