A kind of method of photocatalytic auxiliary chlorine dioxide bleaching pulp

Abstract

The invention discloses a method for bleaching paper pulp through chlorine dioxide under the assistance of photocatalysis. The method comprises steps as follows: 1) photocatalysis pretreatment: a catalyst and a photosensitizer are added to unbleached bagasse slurry for photocatalysis pretreatment under the process conditions as follows: the slurry weight concentration is 8%, the reaction pressure is 0.1 Mpa, the bleaching temperature is 55 DEG C, the usage quantity of photosensitizers is 0.8%-1.2% of the weight of bagasse slurry and the reaction time is 4-4.2 h; 2) chlorine dioxide bleaching: the bagasse slurry is sent into a chlorine dioxide bleaching tower, is treated under the process conditions that the bleaching temperature is 50-60 DEG C, the usage amount of chlorine dioxide is 0.2%-0.4% of the weight of the bagasse slurry and the reaction time is 40 min, and is then sent to a following bleaching section. The unbleached bagasse slurry is subjected to ultraviolet light catalysis pretreatment, the lignin removal rate before decomposition of carbohydrate in paper pulp is accelerated can exceed 70%, the bleachability of the paper pulp is greatly improved, and the AOX content in bleaching wastewater is reduced.

Description

Technical field [0001] The invention relates to a method for bleaching and clean production of pulp in a pulp and papermaking enterprise, in particular to a method for photocatalytic assisted chlorine dioxide bleaching of pulp. Background technique [0002] China is the world's largest producer and consumer of paper and cardboard, with its total production and total consumption ranking first in the world. China is also the world's largest developing country with a large population. With the development of the national economic situation, people's material and cultural life is increasingly enriched and improved, and the demand for paper and cardboard is very strong. Such a large increase in demand has provided a rare opportunity for the development of the paper industry, followed by fierce market competition. In recent years, the competition among pulp and paper companies worldwide has become increasingly fierce. Energy saving, consumption reduction, cost reduction, and improveme...

AI Technical Summary

Problems solved by technology

Although there are individual reports of ongoing small-scale experiments, the current main work on pulp photocatalytic bleaching is still in the initial stage of mechanism exploration or laboratory research.