METHOD OF PRODUCING SEMI-CELLULOSE Russian patent published in 2020 - IPC D21C3/00 

FIELD: paper.

SUBSTANCE: invention relates to pulp and paper industry and can be used in production of fibrous semi-products, in particular, semi-pulp for paper making. Initial raw material for production of semi-cellulose is represented by wood wastes - birch sawdust formed when birch wood is produced from standard chips - basic (traditional) raw material for production of fibrous semi-finished products of pulp-and-paper production. Birch sawdust is loaded into autoclave and filled with neutral sulphite cooking solution heated to temperature of 70–75 °C. Boiling solution contains boiling solution represented by NaOH. Then semi-cellulose is brewed at temperature of 156–165 °C and total duration of 95–115 minutes. Produced semi-cellulose is dissolved in a disintegrator into fibres and bundles of fibres and washed with cold water. Then, sorting is carried out on a laboratory scale and grinding is performed on a centrifugal grinder to 27–32 °SR.

EFFECT: invention simplifies and reduces the cost of the method of producing semi-cellulose, as well as increases environmental friendliness of the process while maintaining quality parameters of the semi-cellulose, which are not inferior to those of the prototype.

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