Process for producing pulp

A pulp and reagent technology, applied in papermaking, textiles and papermaking, pulping with organic solvents, etc., to achieve the effects of favorable methods, improved output and performance, and increased output

Inactive Publication Date: 2004-09-08
CHEMPOLIS OY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Whereas in the alkaline cooking method silicon dissolves in the cooking liquor causing problems

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] Wheat straw was cooked using a mixture of 44% formic acid, 35.2% acetic acid and 2.5% furfural (the rest of the mixture being water) as the cooking agent. The cooking temperature is 125° C., and the cooking time is 35 minutes. The ratio of the cooking reagent to the raw material is 5:1.

[0036] The cooking is carried out in a zirconium-coated cooking reactor with a capacity of 1 liter and dimensions L / D=2.56. The reactor is heated externally.

[0037] Lignin was washed from the resulting delignified pulp with an acid containing 44% formic acid and 35.2% acetic acid. The pulp was then washed at 65°C with a peracid obtained by adding in situ 1% hydrogen peroxide by weight of the fiber stock. After washing, the pulp was deesterified at 70°C to an acid concentration of 10% (4h). Finally, wash the slurry with water.

[0038] The pulp obtained was extracted with alkali and bleached twice with hydrogen peroxide. The brightness of the bleached pulp was 81.7 ISO (measured...

Embodiment 2

[0040] Brown (unbleached) pulp was prepared in the same manner as in Example 1 using wheat straw. Table 1 lists the cooking conditions at different furfural contents (% by weight), while the kappa numbers of the pulps are the same. Furfural, formic acid (HCOOH), acetic acid (CH 3 COOH) and water are based on the total weight of the cooking reagent (% by weight).

[0041] The results in Table 1 show that furfural increases pulp yield.

[0042] Furfural

[0043] * ) yield of fine pulp

Embodiment 3

[0045] Weed grass was cooked in a laboratory digester using a mixture of 42% formic acid, 40% acetic acid and 0.1% furfural (the rest of the mixture being water) as the cooking agent. The cooking temperature is 125° C., and the cooking time is 55 minutes.

[0046] The resulting pulp was washed and deesterified at 95°C using an acid mixture comprising 13% formic acid, 12% acetic acid and 75% water. Table 2 lists the relationship between the content of the compound acid and time expressed by the weight percentage of the pulp.

[0047] Deesterification time (hours)

[0048] The results in Table 2 show that the content of the combined acids decreases with time, that is, the acids are liberated from their esters due to the catalysis of the acids.

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PUM

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Abstract

The invention relates to a process for producing pulp from a fibre-based raw material using, as the cooking reagent, a solvent mixture which is based on organic acids and also contains furfural. The method is applicable to herbaceous plants, in particular.

Description

technical field [0001] The present invention relates to a process for the preparation of pulp, based on organic chemicals, using herbaceous plants, especially cereal straw, as raw material. Background technique [0002] With today's chemical cellulose production methods, cellulose pulp can be produced economically and environmentally friendly from woody raw materials. However, the preparation of environmentally acceptable cellulose from herbaceous, ie, non-woody, materials has not been successful and such methods are either technically infeasible or uneconomical. [0003] To reduce the environmental impact of chemical pulping, organosolvent pulping based on organic cooking solvents ('organosolv' process) has been developed. Organic solvent pulping processes use organic solvents, especially organic acids, during delignification. Some organosolvent pulping methods employ sulfur-free and chlorine-free chemistries, and a closed cycle of chemicals is considered necessary for in...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D21C3/00D21C3/20
CPCD21C3/20D21C3/003
Inventor 艾沙·卢素帕西·卢素朱哈·安提拉帕维·卢素
Owner CHEMPOLIS OY
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