Purification and fractionation of lignosulfonate in thin liquor by ceramic membranes

D. Humpert*, M. Ebrahimi, P. Czermak, University of Mittelhessen, Germany

Lignin is a phenolic macromolecule and belongs, beside cellulose, to the most abundant organic polymers on earth. It occurs mainly on plant cell walls, where it is responsible for the lignification. During paper and pulp production process lignin is separated from cellulose due to the fact that lignin is responsible for the yellowing of the paper. By molecule reduction as well as sulfonation the water insoluble lignin-molecules gets soluble and can be separated from cellulose.
As waste material of this procedure, a complex mixture of organic and inorganic components, arises. In this way the paper industry produced every year more than 50 metric tons of modified lignin, dissolved in the associated waste liquor. The majority is incinerated to produce energy, while a very small part is used to produce low value products like wood glue or wetting agent. The use of technical lignin for chemical products will require enhancements in purity, molecular mass distribution and polydispersity.

There are already procedures to purify lignin, but these procedures are limited by the maximum thin liquor volume. To achieve the goal of a high purified and high volume lignin solution, a membrane process, based on ceramic membranes, is developed...

Session: M5 - Fouling and Ceramic Membranes
Day: 12 October 2016
Time: 16:45 - 18:00 h

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