Andritz Ag

Oleg Shagaev

Lukas Wiesegger

A method for producing a fibrous material from lignocellulose from wood, preferably in the form of wood chips. The lignocellulose material is impregnated with a mixture of sodium sulfite and sodium bisulfite and subsequently undergoes a comminution process in a refiner. Additional chemicals from a mixture of sodium sulfite and sodium bisulfite are directly introduced into the refiner, allowing optimal conditions to be set for both additive flows of chemicals such that the process can be operated in an energetically advantageous manner and corrosion and scale formation in the refiner and subsequent aggregates can be prevented as much as possible.

Method for producing a fibrous material

The invention relates to a process for isolation of hemicelluloses from biomass pulping process waters or spent liquors with removal of suspended solids, concentration of the product and purification of the product by removal of inorganic salts and low molecular weight substances. It is characterized in that the hemicellulose isolation process conditions at several separation/purification stages are adjusted separately by e.g. pH adjustment. The invention further relates to a plant for carrying out the process. With such process and plant it is possible to recover most of the suspended solids, especially xylan and other hemicelluloses.

Growing community of inventors

Vienna, Austria

Oleg Shagaev