OUTLOOK FOR OXYGEN UTILIZATION IN PULP COOKING

A review is presented of investigations into oxygen-alkali pulping conducted in the USSR. It is shown that a pulsation apparatus is suitable for oxygen-alkali pulping of wood. Experimental data obtained on both the laboratory and pilot plant scales are presented. Oxygen-alkali pulp from both hardwood and softwood is obtained in higher yield than sulphate pulp from the same wood species. Unbleached hardwood oxygen-alkali pulp has high brightness (about 60%), and can be bleached to 85-88% brightness without chlorine-containing bleaching agents. After bleaching, the quality of oxygen-alkali pulps from both hardwood and softwood moves closer to that of bleached sulphate pulp. The oxygen-alkali pulping method for producing bleached pulp is ecologically superior to the sulphate process; it is also economically viable.