Method for producing chemical wood pulp

Abstract

This invention is a chemical wood pulp productive method. It contains following steps: 1) To soak, Put the thin piece wood plate into the soak liquid container, the soaking temperature is 50-90 deg.C. Soaking time is 15-50 minutes; the soak liquids use part or whole boiling liquid. 2) To relieve squeeze and press; relieve the pressed wood plate, the pressing ratio is 3-6:1. 3) To take-out lignin: put the pressing wood plate and its soak liquid into the boiler, boiling them to do the reaction of take-out lignin.

Description

(1) Technical field [0001] The invention relates to a method for producing pulp, in particular to a method for chemically producing wood pulp. (2) Background technology [0002] Pulp and paper making is a capital, energy and technology-intensive industry. According to statistics in 1995, the total sales of the global paper industry reached 260 billion U.S. dollars, with assets of 400 billion U.S. dollars. The status of the industry is second only to the telecommunications industry and the automobile industry, and the development of the industry is consistent with the growth of the national economy. At present, the world's pulp production is over 174 million tons. [0003] Wood has a series of advantages such as stable and concentrated supply, high pulping strength, and good papermaking performance, so it has become the main fiber raw material in the pulp and paper industry. The proportion of wood pulp in the world accounts for more than 95%, and chemical wood pulp accounts ...

AI Technical Summary

Problems solved by technology

[0005] (1) Due to the dense wood structure, the penetration of the cooking liquid into the wood chip and the dissolution of the reaction product during the cooking process are difficult, resulting in problems such as large amount of chemicals, long cooking time and high steam consumption in the production of wood chemical pulp.

In addition, the difficult penetration of cooking liquid also causes uneven pulp quality and high sieve rate

[0006] (2) For tree species with high basic density, such as older eucalyptus, it is difficult for cooking aids such as anthraquinone to penetrate into the interior of wood chips, and cannot play the role of cooking aids in accelerating the delignification reaction and protecting carbohydrates

[0007] (3) Harder tree knots are associated with the wood. These knots need to be removed before cooking. If they are mixed in a digester for cooking, it will be difficult for the liquid to penetrate. Generally, they are screened out as pulp residue, resulting in a large amount of waste of fiber raw materials.

In addition, the equipment investment in the cooking section of chemical wood pulp is relatively large

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