Technical Bulletin No. 0039: Survey of Current Black Liquor Oxidation Practices in the Kraft Industry (AQTB)

The role of black liquor oxidation in reducing the emission of hydrogen sulfide at the contact evaporator has been sufficiently well demonstrated in full scale applications to be accepted as one of the most significant, if not the most significant, single step that can be taken to reduce hydrogen sulfide emission in the kraft industry. While oxidation of black liquor is a reality, unanswered problems continue to arise in its application, and areas of research needs, such as (a) the role of oxidation in controlling organic sulfur emission (b) the effect of high temperature on oxidation rate, (c) instrumental control of oxidation process, and others, have been identified. It is expected that better than one-half the nation's kraft mills will have black liquor oxidation facilities installed by 1969, while significant numbers of existing units will be expanded or modified to maintain or upgrade existing oxidation efficiency, or to assure improved continuity of operation at the desired level of efficiency.