Membrane technology in the pulp and paper industry

Abstract Membrane filtration is today an industrial process in the pulp and paper industry. The rising demand for environmental protection, energy savings and recovery of valuable products has accelerated the application of membrane filtration. The most important applications in the pulp and paper industry are: • Recovery of valuable products - Fractionation and purification of lignosulphonate from spent sulphite liquor; fractionation and purification of lignin from kraft black liquor. • Energy savings - Concentration of dilute spent sulphite by membrane filtration requiring lessenergy than evaporation. • Environmental protection - Purification of effluents from kraft bleach effluent. The DDS RO-system is of the plate and frame system. DDS started the development of membrane filtration in the pulp and paper industry in 1971, and the first plant was installed in 1973.