Kinetic Studies of Kraft Pulping (Part 5) Delignificaton Rate of Rhizophora sp. and Eucalyptus calophylla

Abstract

The kinetic equation, established in the previous paper for Japanese oak (Quercus mongolica), was applied to describe the delignification of mangrove (Rhizophora sp.) and eucalyptus (E. calophylla) during kraft cooking. Although the lignin contents of uncooked wood chips and the apparent delignification patterns of those three wood species differe from one another, the values of rate constants and activation energies were identical respectively. According to the above kinetic equation, the distinction of apparent delignification patterns, which depended on the wood species, were described by the term “L∞”(lignin content at the cooking time t→∞) and the lignin content at the starting point of bulk delignification. Consequently, the kinetic model proposed by us seemed to be preferred for general use in describing the delignification during kraft cooking quantitatively.