Wood pulp, delignification

Wood Delignification. The production of wood pulp (qv) for the paper (qv) industry consists of removing lignin (qv) from wood chips, thus freeing the cellulose fibers. An aqueous solution containing 30—70 wt % sulfolane efficiently extracts the lignin from aspen, Western hemlock, and Southern pine wood... 

There are several modifications of the sulfite method which are designated according to the pH of the cooking liquor (Table 7-1). For the production of chemical pulps, delignification is allowed to proceed until most of the lignin in the middle lamella is removed after which the fibers can be readily separated from each other. Semichemical pulps are often produced by the neutral sodium sulfite method followed by mechanical fiberization of the partially delignified wood. 

The isolation of cellulose from wood may employ any one of several process options [13,15, 16]. Chemical wood pulp may be derived by delignification using acidic solutions of sulfur... 

BJ Fergus, DAI Goring. The Topochemistry of Delignification in Kraft and Neutral Sulphite Pulping of Birch Wood. Pulp Pap Mag Can 69(9) T314-T322, 1969. 

RH Atalla, lA Weinstock, JS Bond, RS Reiner, DM Sonnen, CJ Houtman, RA Heintz, CG Hill, CL Hill, MW Wemple, YuV Geletii, EMG Barbuzzi. Polyoxometalate-based closed systems for oxidative dehgnification of wood pulp fibers. In DS Argyropoulos, ed. Oxidative Delignification Chemistry Fundamentals and Catalysis. ACS Symposium Series, 785, pp. 313-326, 2001. 

T Dumonceaux, K Bartholomew, L Valeanu, T Charles, F Archibald. Cellobiose dehydrogenase is essential for wood invasion and nonessential for kraft pulp delignification by Trametes versicolor. EnzMicrob Technol 29(8-9) 478-489, 2001. 

Considerable interest has been shown in the use of anthraquinone in wood pulping operations. The optimal yield of pulp and pulp viscosity at a given Kappa number was obtained with 0.25 M-NaOH. The rate of delignification was... 

---