Novel non-chlorine bleaching technique for bamboo pulp

A completely chlorine-free, new technology, applied in the technical field of pulp bionic bleaching, can solve the problems of affecting the paper strength of pulp and the large amount of toxic substance pyridine, and achieve the effects of improving various properties, excellent pulp performance and reducing treatment costs.

Inactive Publication Date: 2008-01-23
KUNMING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, while the GIF system degrades lignin, it also degrades cellulose more seriously, which affects the paper strength of pulp. In addition, the amount of toxic substance pyridine in the system is also large. These defects make it difficult for industrial applications. with certain difficulties

Method used

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  • Novel non-chlorine bleaching technique for bamboo pulp

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Dissolve 2.5 grams of ethylenediamine and 8.5 milliliters of salicylaldehyde in 18 milliliters of methanol, stir in an ice-water bath for 30 minutes, let stand for 15 minutes, filter under reduced pressure, wash with 1 milliliter of ether, and dry at 33°C for 6 hours , a light yellow solid was obtained. Then recrystallize with 160 ml of absolute ethanol, and dry at 33° C. for 18 hours to obtain Schiff base salen.

[0026] Dissolve 13 mmol of Schiff base salen in 150 ml of methanol, weigh another 13 mmol of cobalt acetate tetrahydrate, dissolve in warm water, quickly transfer to the above reaction bottle, and quickly form a brown precipitate, 70 ° C ~ 80 ° C Heat to reflux for 1 hour, the brown precipitate turns into dark red crystals, cool to room temperature, transfer the crystals to a sand core funnel, filter with suction, and dry to obtain Co-salen.

[0027] In bamboo pulp with a concentration of 6% by weight, the amount of NaOH is 3.0%, H 2 o 2 The consumption is...

Embodiment 2

[0029] Dissolve 2.0 g of ethylenediamine and 6.8 ml of salicylaldehyde in 14.4 ml of methanol, stir in an ice-water bath for 30 minutes, let stand for 15 minutes, filter under reduced pressure, wash with 1 ml of ether, and dry at 33°C for 6 hours , a light yellow solid was obtained. Then recrystallized with 128 ml of absolute ethanol, dried at 33° C. for 18 hours to obtain Schiff base salen.

[0030] Dissolve 10.4 mmol of Schiff base salen in 120 ml of methanol, weigh another 10.4 mmol of zinc acetate dihydrate, dissolve in warm water, quickly transfer to the above reaction bottle, and quickly form a brown precipitate, 70 ° C ~ 80 ° C Heat to reflux for 1 hour, the brown precipitate turns into dark red crystals, cool to room temperature, transfer the crystals to a sand core funnel, suction filter, and dry to obtain Zn-salen.

[0031] In bamboo pulp with a concentration of 5.0% by weight, the amount of NaOH is 2.4%, H 2 o 2 The consumption is 0.9%, the metal salen consumptio...

Embodiment 3

[0033] Dissolve 3.0 g of ethylenediamine and 10.2 ml of salicylaldehyde in 21.6 ml of methanol, stir in an ice-water bath for 30 minutes, let stand for 15 minutes, filter under reduced pressure, wash with 1.2 ml of ether, and dry at 33°C for 6 hours , a light yellow solid was obtained. Then recrystallized with 192 ml of absolute ethanol, dried at 33° C. for 18 hours to obtain Schiff base salen.

[0034] Dissolve 15.6 mmol of Schiff base salen in 180 ml of methanol, weigh another 15.6 mmol of nickel acetate tetrahydrate, dissolve in warm water, quickly transfer to the above reaction bottle, and quickly form a brown precipitate, 70 ° C ~ 80 ° C Heat to reflux for 1 hour, the brown precipitate turns into dark red crystals, cool to room temperature, transfer the crystals to a sand core funnel, filter with suction, and dry to obtain Ni-salen.

[0035] In bamboo pulp with a concentration of 4% by weight, the amount of NaOH is 2.7%, H 2 o 2 The consumption is 0.8%, the metal salen...

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Abstract

A novel totally chlorine-free bamboo-pulp bleaching process is provided. The invention relates to a novel totally chlorine free (TCF) bamboo-pulp bleaching process, is a new bionic bleaching technology for paper pulp. The invention essentially comprises the following procedures: (1) Synthesizing enzyme-imitated metal salen, using Schiff base salen to react with metallic organic acid salt to synthesize metal salen; (2) Pre-treatment bleaching bamboo pulp, carrying out bleaching pre-treatment on the oxygen delignification sulfate bamboo pulp with metal salen, NaOH, H2O2 and O2 existing; (3) Subsequent TCF bleaching, carrying out three bleaching treatments, namely, alkaline treating enhanced by hydrogen peroxide, bleaching by peroxy acid and bleaching by hydrogen peroxide the bamboo pulp pre-treated by enzyme-imitated metal salen. For the invention, the source is wide, the metal salen is easy to synthesize, the yield rate is high, the cost is low, the consumption is very low; the metal salen is easy to store, has no demanding requirement on the environment, can obviously improve the whiteness of paper pulp, reduce the load of waste water pollution in bleaching, and saves the use of bleaching chemicals.

Description

technical field [0001] The invention relates to a new technology of fully chlorine-free (TCF) bleaching of bamboo pulp, which is a novel pulp bionic bleaching technology. Background technique [0002] Due to the requirements of environmental protection and the development of biotechnology, biological enzymes, as a catalyst with high efficiency and high selectivity, are widely used in pulp bleaching industry. At present, the biological enzymes that have been studied more deeply and widely used mainly include hemicellulase (xylanase, polymannase) and ligninase (lignin peroxidase, manganese peroxidase and laccase). category. They act with certain components in the pulp to form delignification or conditions conducive to delignification, and improve the bleachability of the pulp or increase the whiteness of the pulp. [0003] However, the limited sources of natural biological enzymes, difficulty in preparation, and sensitivity to environmental conditions all restrict its develo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D21C9/16D21C9/147
Inventor 周学飞贾艳迪
Owner KUNMING UNIV OF SCI & TECH
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