COKING OF SPENT PULPING LIQUORS WITH SUBSEQUENT SO{11 {11 ABSORPTION

摘要

Spent Sulfite liquor from a sulfite mill digester is preheated and then heated in a closed system at a temperature in the range of 450 DEG to 700 DEG F under autogenous pressure for a period of 0.5 minutes to six hours to form an effluent liquid and a sulfur-containing coke. The coke is burned to furnish steam for the process and flue gas from which the SO2 evolved is absorbed by the effluent liquid thus forming additional cooking liquor which is recycled to the digester. Volatile gases from the digester are also oxidized to SO2 which is combined with that formed by burning the coke.