Concomitant production of dissolving pulp, polymeric xylan and lignin from birch wood

Pulping methods

Pulping processes can be divided into two primary classes: chemical and mechanical pulping processes.

Mechanical pulping processes utilise thermally or chemically pre-treated wood chips and grinding procedures

to achieve mechanical defibration, whereas chemical pulping processes degrade lignin and separate the

wood into individual cellulose fibers by cooking the wood chips with strong chemicals under high pressure

[1]. Production costs in chemical pulping methods are generally higher than in mechanical pulping processes,

but paper manufactured from chemical pulp is much stronger and has better optical properties [2]. Novel

methods for pulping include soda-anthraquinone (SAQ) [3] and organosolv [4] pulping processes.

[1] Sixta, H., Handbook of Pulp, Wiley-VCH, Weinheim 2006, 1369 p.

[2] http://www.paperonline.org/paper-making/paper-production/pulping/types-of-pulping-processes

[3] Testova, L., Roselli, A., Costabel, L., Kovasin, K., Tenkanen, M., Sixta, H., Combined Production of Polymeric

Birch Xylan and Paper Pulp by Alkaline Pre-extraction Followed by Alkaline Cooking, ACS Publications (2014)

[4] Chong, E., Chiang, L.W., Comparative Study Between Organosolv Pulping Using Different Concentrations

of Ethanol and Kraft Pulping of Acacia Hybrid, Agriculture & Forestry Vol. 60 Issue 2 (2014) 47-57