Treatment method of wood fiber raw material

Abstract

The invention provides a treatment method of wood fiber raw materials, which includes the following steps: (1) pre-impregnation: impregnating the wood fiber raw materials in a Na2CO3 water solution; and (2) steam-boiling: steam-boiling the impregnated wood fiber raw materials with an organic acid water solution as a steam-boiling solvent with addition of an inorganic acid as a catalyst. In the invention, by means of synergistic effect between the pre-impregnation with the Na2CO3 water solution and the steam-boiling of the organic acid water solution and the inorganic acid, yield of paper pulp is increased, ash content is reduced and comprehensive performance of the paper pulp is improved.

Description

technical field [0001] The invention belongs to the field of processing lignocellulosic raw materials, and in particular relates to a method for processing lignocellulosic raw materials. Background technique [0002] my country is a big country that uses non-wood raw materials to make pulp and paper. Most of the current pulping of non-wood raw materials adopts alkaline pulping process, that is, sodium hydroxide or sodium sulfide is used as the main cooking liquid. This method has the following disadvantages: 1. In alkaline pulping, there is a large amount of silicon in lignocellulosic raw materials Soluble in cooking black liquor, on the one hand, affects the further removal of lignin and hemicellulose in fiber raw materials, on the other hand, due to the complexity of cooking reagents in alkaline pulping, it is difficult to recover cooking black liquor, and the Reagents need to be reused independently by setting up a complex alkali recovery process, and the lignin and hemi...

AI Technical Summary

Problems solved by technology

Most of the current pulping of non-wood raw materials adopts alkaline pulping process, that is, sodium hydroxide or sodium sulfide is used as the main cooking liquid. This method has the following disadvantages: 1. In alkaline pulping, there is a large amount of silicon in lignocellulosic raw materials Soluble in cooking black liquor, on the one hand, affects the further removal of lignin and hemicellulose in fiber raw materials, on the other hand, due to the complexity of cooking reagents in alkaline pulping, it is difficult to recover cooking black liquor, and the Reagents need to be reused independently by setting up a complex alkali recovery process, and the lignin and hemicellulose in the black liquor are difficult to effectively extract, and the economic benefit is poor; 2. The reaction temperature and pressure of alkaline pulping are high, and the production requires equipment High, difficult process

[0005] The patent CN1527896 of Camplis Company of Finland discloses a method for producing pulp by using a mixture of acetic acid and formic acid as a cooking reagent. The cooking solvent also includes other chemical substances such as furfural. This method is extremely corrosive to formic acid, so the requirements for equipment and processes Very high, resulting in high production costs; in addition, there are many types of substances in the cooking liquid and the boiling points of formic acid and acetic acid are close, which makes it difficult to separate and recycle various substances in the system after cooking, which increases costs

[0006] In another patent CN1299424 of Camplis Company, formic acid is used as the main cooking agent, and a small amount of acetic acid is added as an additional cooking agent. In addition to the shortcomings described in the patent CN1527896, it is difficult to realize the production of fiber raw materials under normal pressure in this method. Effective cooking, lignin and hemicellulose cannot be effectively removed, so cooking must be completed under high pressure conditions, high equipment costs, and reduced safety

[0007] CN101864683A discloses a pretreatment method for lignocellulosic raw materials. In this method, lignocellulosic raw materials, acetic acid, and catalysts are mixed and heated, followed by steps such as fiber washing, inorganic acid or alkali treatment, and fiber washing. Finally, the black liquor is recycled for at least three times Afterwards, the recovery of the drug is carried out. The process is complicated and takes a long time. Due to the repeated heating of the cycle, and the inorganic acid or alkali treatment of the fiber in the subsequent section, the cellulose is severely hydrolyzed, and the final fiber product can only be used. Enzymatic fermentation, not suitable for making paper fiber, especially high quality paper fiber

[0009] In traditional organic solvent pulping methods, such as formic acid method, acetic acid method, methanol method, formic acid-acetic acid mixed method, etc., most of the silicon in the plant fiber raw material remains in the fiber and is difficult to dissolve, resulting in high ash content in the obtained pulp , poor papermaking performance

[0010] In the IDE pulping method, Na 2 CO 3 The solution pre-impregnates the lignocellulosic raw material, and then cooks the raw material in the ethanol solution to remove the lignin. In this method, the main cooking reagent is ethanol, but ethanol is very dangerous when heated at high temperature, and it is easy to cause accidents such as combustion and explosion. Industrialization is extremely difficult

Images