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

A chemical agent, formic acid technology, applied in the direction of pulping with salt/anhydride, pulping with organic compounds, pulping with organic solvents, etc., can solve the problems of poor pulp strength and so on

Inactive Publication Date: 2001-06-13
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 produ...

Method used

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Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

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

[0031] Determination of Drainage Resistance of Pulp by the Schopper-Riegler Method (SCAN-C 19:65)

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

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

[0034] Comminution of pulp in PFI pulverizers (SCAN-C24:67).

Embodiment 1

[0036] 600 kg of Reed Grass pulp was prepared from ungraded chopped Phragmites phylloxera reed. 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 bar and the cooking time is 50 minutes. The resulting cellulose was bleached with two-stage alkaline hydrogen peroxide.

[0037] raw material

fiber

Proportion

% / %

light scattering

rice 2 / Kilogram

opaque

Spend%

Bulk

cm 3 / gram

porosity

ml / min

After pressing

D.S.

%

tear strength

cd

Millinewton meter 2 / gram

tensile strength

md

Nm / g

RCG / P

50 / 50

44.4

82.7

1.43

992

45.7

9.0

40.6

B / P

50 / 50

38.0

79.6

1.39

689

44.3

8.6

51.2

[0038] RCG=Reed ...

Embodiment 2

[0045]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. The chestnut chips were cooked under the following conditions; the cooking liquid had a formic acid content of 72%, an acetic acid content of 10% and a water content of 18%, a cooking temperature of 120° C., a pressure of 2.0 bar, and a cooking time of 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.

[0046] According to the test results, the obtained chestnut wood pulp has quite acceptable properties.

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PUM

PropertyMeasurementUnit
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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

Background of the invention [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. [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 an additio...

Claims

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Application Information

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IPC IPC(8): D21C3/00D21C3/20
CPCD21C3/003D21C3/20
Inventor 帕西·罗素帕维·罗素艾沙·罗素
Owner CHEMPOLIS OY
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