Kinetics of delignification and hexenuronic acid decomposition during kraft pulp bleaching with peroxyacetic acid

摘要

This paper presents kinetic equations for the remo- val of lignin and hexenuronic acid from an oxygen-delighnified kraft pulp. Lignin removal is descried as a single reaction. The rate of This reaction increases with increasing temperature, pH and lignin And peroxacetic acid concentrations. The reaction order with Respect to lignin is high (4.1), probably because the single reac- Tion is actually a combination of several parallel and consecutive Reactions. The reaction orders with respect to peroxyacetic acid And hydronium ion are 1.37 and -0.29, respectively. The activa- Tion energy of delignification is 80 kJ/mol.