Technical Bulletin No. 0721: Air Emissions of Acetaldehyde, Methanol, and Methyl Ethyl Ketone from Kraft Mill Deknotters, Pre-washer Screens, and Weak Black Liquor Storage Tanks

Tests using the NCASI impinger method were conducted at four deknotter systems and six weak black liquor storage tanks to measure volatile organic HAP emissions. The results of these tests, when combined with the results of tests conducted during the MACT study, show that (1) methanol was the only HAP present at a significant concentration in deknotter system, pre-washer screening system, and weak black liquor storage tank vents, (2) methanol content of vent gases from six of the seven deknotters tested averaged 0.022 lb/ODTP and from one deknotter system, which was connected to an NCG system, averaged 0.