Method for preparing bamboo pulp by full-liquid-phase prehydrolysis sulfate displacement cooking process

Abstract

The invention discloses a method for preparing bamboo pulp by a full-liquid-phase prehydrolysis sulfate displacement cooking process, which comprises the following steps: preparing materials, washing the materials, prehydrolysizing, cooking, washing, screening, bleaching, regulating polymerization degree, dechlorinating and conducting acid treatment. According to the preparation method, after the cooking is finished, for the obtained pulp, the content of alpha cellulose is more than or equal to 95%, the pepentosan is more than or equal to 4%, and the average polymerization degree is 550-650; after the acid treatment is finished, for the obtained pulp, the content of alpha cellulose is more than or equal to 94%, the pentosan is less than or equal to 3.0%, the average polymerization degree is 400-500, and the white degree is 86-89%. The method has the following advantages: the whole set of technology of full-liquid-phase prehydrolysis, full-liquid-phase cooking, hydrolyzate recovering and recovered black liquid displacement cooking, not only is the waste water pollution degree is alleviated, the temperature rising time and steam amount are saved, the trebling effects of energy saving, emission reduction and yield increasing are achieved, and the problems that the waste water pollution is serious, the energy consumption is high and the output is low in the pulp prepared by the current prehydrolisis sulfate method.

Description

Technical field [0001] The invention belongs to the technical field of chemical fibers, and specifically relates to a method for preparing bamboo pulp by all-liquid-phase pre-hydrolyzed kraft displacement cooking. Background technique [0002] In recent years, as the global energy shortage problem has become increasingly prominent, the prices of non-renewable resources such as coal and oil have continued to rise, causing the price of petrochemical synthetic fibers to rise. Therefore, the search for renewable fibers has become a new trend in the future. Although cotton-like natural fibers have excellent spinnability and reproducibility, their prices are still rising due to their limited production capacity, which is far from meeting the huge fiber market demand. Therefore, another type of renewable fiber-viscose fiber is emerging and becoming the mainstream of renewable fibers. [0003] Among viscose fibers, viscose fibers produced by dissolving spinning technology using wood pulp ...

AI Technical Summary

Problems solved by technology

However, the pre-hydrolyzed sulfate method currently adopted at home and abroad uses semi-liquid phase hydrolysis and cooking, so the uniformity of hydrolysis and cooking is still not ideal, and the hydrolyzate is directly discharged, which wastes a lot of heat energy and water resources, and the heating time is relatively short. long, so there are still outstanding problems of high energy consumption, unstable hydrolysis, large discharge liquid pollution, and low production capacity, so the production capacity of bamboo pulp is limited to a certain extent