METHOD OF PREPARING PULP FROM CELLULOSE-CONTAINING MATERIAL Russian patent published in 1999 - IPC

FIELD: paper-and-pulp industry. SUBSTANCE: material is mixed formic acid (solvent) and mixture is digested at temperature close to boiling temperature of solvent using backflow condenser. Cellulose-containing material originates from annual plants, hardwood and softwood. According to one of preferable embodiments of invention, cellulose-containing material is first slightly warmed under backflow condenser, after which strictly simplified amount of hydrogen peroxide is slowly added at constant dosage preferably avoiding utilization of external power sources. Such method implementation mode can be repeated in the same cycle at reduced digestion temperature. Resulting pulp is preferably used to prepare cellulose mainly for manufacturing paper or cardboard. Lignin isolated from cellulose-containing material by precipitating it in water after separation of pulp from solvent can also be designed for further use, in particular, as new building material, filler, or as starting substance for preparing aromatizers. EFFECT: enhanced process efficiency. 22 cl, 2 tbl