Technical Bulletin No. 0054: Submerged Combustion Evaporation of Neutral Sulfite Spent Cooking Liquor

In an effort to find a less costly means of evaporating neutral sulfite semi-chemical pulping waste liquor, pilot plant experiments were conducted on submerged combustion. These tests were conducted by engineers of the Ozark-Mahoning Company and the National Council's Louisiana State University project with equipment made available by the former organization. It appears from the data obtained that while the capital cost for applying submerged combustion is considerably lower than that required for conventional methods, operating cost, even when cheap natural gas is used as fuel, is higher. This would also be the case if submerged combustion was operated in multiple effect and a use was available for the low pressure steam produced. Further testing of the process awaits an expression of interest in the process by semi-chemical pulp manufacturers. The Council wishes to express its appreciation for the cooperation of Mr. W. I. Weisman of the Ozark-Mahoning Company who made this investigation possible.