Displacement Cooking of Wheat Straw

摘要

Displacement pulping process removes the easily soluble fractions of extractives, lignin and hemicelluloses at the end of first stage, so the interference of these materials in second stage can be avoided. Reusing spent black liquors from previous cooks enables retention of liquor heat and utilization of residual alkali. The other advantage is to produce the pulp with lower permanganate number but without affecting its strength.