A method for preparing dissolving pulp from bleached bamboo pulp board

Abstract

The invention discloses a method for preparing dissolving pulp from a bleached bamboo pulp board. The method comprises the following steps: (1) first-stage alkaline treatment; (2) second-stage alkaline treatment; (3) biological enzyme treatment. According to the method, the single-stage sodium hydroxide solution treatment in the prior art is changed into two-stage alkaline treatment, and bamboo dissolving pulp with high reactivity is acquired via improvement of alkaline treatment follow-up processes and process technical parameters. The method facilitates improving of the appearance quality of dissolving pulp and the using effect of the final product; as the crushing treatment step is added, reduction of the follow-up consumption of a chemical reagent, lowering of the manufacturing cost and improvement of the producing economy efficiency are facilitated.

Description

technical field [0001] The invention relates to the technical field of bamboo dissolving pulp, in particular to a method for preparing dissolving pulp from bleached bamboo pulp boards. Background technique [0002] Dissolving pulp is a kind of high-purity refined pulp dissolving pulp. It is mainly used in the production of viscose fiber for textiles, and is also used as cellulose acetate (cigarette filter material), cellophane, nitrocellulose, and carboxymethyl cellulose (CMC). and other raw materials for cellulose derivatives. With its excellent natural and environmental performance, viscose fiber will further increase the demand for dissolving pulp. It can be seen that it will still be a period of rapid growth in the future. Wood and linters have long been the main raw materials for dissolving pulp. [0003] In recent years, with the rapid development of global industrialization and rapid population growth, the forest area has been greatly reduced and the production of c...

AI Technical Summary

Problems solved by technology

Although the sulfite method has played an important role in the preparation technology of dissolving pulp, with the deepening of the concept of sustainable development, the sulfite method has gradually exposed problems, mainly due to the presence of hemifiber in the pulping waste liquid. Lignin and lignin, accompanied by different degrees of degradation products, resulting in complex composition of waste liquid, increased difficulty in wastewater treatment, poor uniformity of polymerization degree distribution of dissolving pulp, and low reactivity

Prehydrolysis is currently the most commonly used method. Although the prehydrolysis sulfate method can effectively remove hemicellulose and increase the cellulose content in bleached pulp, the entire process is cumbersome and complicated, and the consumption of chemical reagents is large, especially the prehydrolysis process. The consumption time is long, generally more than 4-5 hours, the acidic environment generated during the treatment (including hydrochloric acid, sulfuric acid added during pretreatment and the removal of acetyl groups or uronic acid groups on the side chains of hemicellulose Acidic substances such as acetic acid) will seriously corrode the equipment, and it is also easy to cause acidic hydrolysis of cellulose. The content of α-cellulose in the dissolving pulp is low, and the degree of polymerization is not uniform, which reduces the yield and viscosity of the pulp, and the reaction of the dissolving pulp poor performance

Although kraft cooking can obtain a high yield of dissolving pulp, the content of hemicellulose in the dissolving pulp is still high, and it faces problems such as poor reactivity of dissolving pulp