Electrochemical delignification of wood pulp using polyoxometalate mediators

Abstract

It has been found that polyoxometalates (POMs) can act as mediators in the electrochemical oxidation of lignin in pulps. An electrochemical cell, with a Nafion® membrane separating the anode and cathode compartments, was used in the delignification experiments. A softwood kraft pulp was placed in the anode compartment with a buffered 0.01M solution of the polyoxometalate Na5[SiVW11O40]. During electrolysis the lignin content of the pulp was reduced from kappa number 26 to 6. The energy required for this delignification was equivalent to 120 kW·hr per ton of pulp. At $0.05/ kW·hr, the cost for this 20-point drop in kappa number would be $6 per ton of pulp. Based on this and other data, it may be both technically and economically feasible to delignify pulps electrochemically using POMs as mediators. The POMs are neither consumed nor modified during the reaction and can, therefore, be recovered and reused in this novel, closed-mill, delignification process.

Citation

Reiner, R.S.; Springer, E.L.; Atalla, R.H. 2003. Electrochemical delignification of wood pulp using polyoxometalate mediators. Managing the treated wood resource--II : special seminar sponsored by American Wood-Preservers'' Association [and] Utility Solid Waste Activities Group : Thursday, May 1, 2003 ... Boston, Massachusetts. Selma, Ala. : American Wood-Preservers'' Association, c2003: [10] Pages