Process for producing pulp with a mixture of formic acid and acetic acid as cooking chemical

A technology of chemical agents and mixtures, which is applied in the fields of pulping with acid salts/anhydrides, pulping with organic compounds, pulping with organic solvents, etc., and can solve problems such as poor pulp strength

Inactive Publication Date: 2004-10-06
CHEMPOLIS OY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that it produces a pulp with poor strength compared to kraft pulping

Method used

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Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0030] Preparation of laboratory paper / handsheet of pulp for determination of physical properties (SCAN-C26:76),

[0031] Determination of Drainage Resistance of Pulp by Schopper-Riegler Method (SCAN-C19:65)

[0032] Kappa number of chemical pulp (SCAN-C1: 77),

[0033] Xylose content of pulp (calculated as pentosan content) (SCAN-C4: 61)

[0034] Pulverization of pulp in PFI pulverizer (SCAN-C24: 67)

Embodiment 1

[0036] 600 kg of Reed Grass pulp was prepared from ungraded shredded Phragmites reeds. The cooking conditions are as follows: the formic acid content of the cooking liquid is 70 to 75%, the acetic acid content is 10%, and the water content is 15 to 20%; the cooking temperature is 115 to 120°C; the pressure is 1.5×10 5 N / m 2 (1.5 bar) and a cooking time of 50 minutes. The resulting cellulose was bleached with two-stage alkaline hydrogen peroxide.

[0037]The reed grass pulp obtained in this way was used to produce fine paper on a pilot scale, using a fiber composition of 50% reed grass pulp and 50% pine pulp prepared by the kraft process. Reed grass pulp is not refined. High quality commercial pine / birch kraft pulp (50% pine pulp and 50% birch pulp) was used as control pulp. The pulp is operated at a speed of 900 to 1300 m / min. The reed grass pulp handled very well at all speeds. Compared with the control pulp, operated under the same conditions, the reed grass pulp is be...

Embodiment 2

[0046] Chestnut wood pulp (chestnut wood purchased from France) was prepared by cooking nine times on a laboratory scale. The fiber length of chestnut wood pulp is close to that of herbaceous plants. Cook chestnut chips under the following conditions; the formic acid content of the cooking liquid is 72%, the acetic acid content is 10% and the water content is 18%, the cooking temperature is 120°C, and the pressure is 2×10 5 N / m 2 (2.0 bar), cooking time 50 minutes. The resulting pulp is bleached with two-stage alkaline peroxides. The Schopper-Riegler value of the brown pulp was 18.5, the Kappa value was 27.6, and the tensile index of the unground test paper was 76.2. The Schopper-Riegler value of the bleached pulp was 18.0, the brightness 81.9% (ISO), and the unground tensile index 37.5.

[0047] According to the test results, the obtained chestnut wood pulp has quite acceptable properties.

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PUM

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Abstract

The invention relates to a process based on formic acid cooking for producing pulp from herbaceous plants and deciduous trees by using acetic acid as an additional cooking chemical. The obtained pulp can be used in fine paper and board production as short-fibred material, for instance. The invention also relates to a process for adjusting the hemicellulose content of the pulp in connection with the formic acid cooking by using acetic acid as an additional cooking chemical.

Description

technical field [0001] This invention relates to the use of acetic acid as an additional cooking chemical when formic acid is used to cook herbs and hardwoods to produce pulp. The pulp produced by this method can be used as short fiber raw material in the production of high-grade paper and cardboard. The present invention also relates to the method of using acetic acid as an additional cooking chemical in the process of beating with formic acid to adjust the hemicellulose content in pulp. Background technique [0002] The amount of hemicellulose in plants is 15 to 30% on a dry matter basis. Hemicellulose and cellulose molecules are not chemically bound to each other, but they are linked by hydrogen bonds and van der Waals forces. Typically, hemicellulose is relatively readily hydrolyzed by the action of strong bases and acids. [0003] Finnish patent application 933729 discloses a process for producing pulp using acetic acid as the main cooking chemical and formic acid as...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): D21C3/00D21C3/20
CPCD21C3/20D21C3/003
Inventor 帕西·罗素帕维·罗素艾沙·罗素
Owner CHEMPOLIS OY
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