TH16206A - Method for bleaching the pulp without using chemicals containing chlorine. - Google Patents

Abstract

The invention involved a process for producing pulp which was boiled under alkaline conditions and which was bleached by Do not use bleach. Containing chlorine, in which chemical processes The used boil was recovered in the first recovery unit (18) and the used bleach chemical was recovered in the second and good recovery unit (12). All or part of these bleaching chemicals should be borne and used again in a single step. Removes lignin with oxygen (7) and / or during bleaching step TCF (9).

Claims (2)

1. The process for producing pulp that is boiled under alkaline conditions and mainly is bleaching without the use of bleaching chemicals. Chlorine-like That said, the boiling chemicals were recovered in the first recovery unit (18), the used bleach chemicals were fully or partially recovered in the second recovery unit (12), which should be good at rejuvenating them. The chemical is used for all or part of the bleach and is reused in the oxygen lignin removal step (7) and / or in the TCF bleaching step (9). 2. The process according to claim 1 looks at before the tag step: