METHODS FOR THE OXYGEN-BASED DELIGNIFICATION OF PULP

摘要

Pulp is delignified by forming a mixture of pulp and caustic, adding oxygen and feeding this oxygen-containing mixture to a first step reactor. The lignin in the oxygen-containing mixture will be partially delignified and will be fed to a second step reactor where the remainder of the lignin in the pulp will be delignified. In this manner, fast reacting lignin can be treated in the first step reactor and slow reacting lignin can be treated in the second reactor. The delignified pulp is recovered from the apparatus and after washing can be forwarded to a bleaching unit.

主权项

1. A method for delignifying pulp comprising the steps of:
(a) Forming a mixture of the pulp and caustic; (b) Feeding oxygen to the mixture and feeding the oxygen-containing mixture to a first step reactor wherein lignin will delignify; (c) Feeding the oxygen-containing mixture to a second step reactor wherein lignin will delignify; and (d) Recovering the delignified pulp.