FOERFARANDE FOER DELIGNIFIERING AV TRAEMATERIAL MED EN ALKALISK KOKVAETSKA SOM VAESENTLIGEN ICKE INNEHAOLLER SVAVELHALTIGAFOERENINGAR

摘要

An improved alkaline lignocellulosic pulping process wherein improved colour in the resultant pulp is obtained by using an excess of alkali based on the lignocellulosic material. Improved pulp strength is obtained by operating the delignification process at lower temperatures than normal generally from 100.degree.C to 160.degree.C. Both of the above improvements are enhanced and pulping times are reduced if the pulping liquors additionally contain a quinonoid or hydroquinonoid compound or tautomer thereof.