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Production process of bleached chemical pulp with hemp stalk core

A technology for chemical pulp and hemp core rod, which is applied in pulp bleaching, pulp fat/resin/asphalt/wax removal, pulping with inorganic alkali, etc. Effects of chemical and energy consumption, reduction of wastewater discharge

Inactive Publication Date: 2006-08-02
SOUTH CHINA UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Because this method uses mechanical shearing to disperse the raw materials into pulp, and adopts lignin-retaining bleaching, the whiteness of the obtained pulp generally does not exceed 60% ISO, and the strength is also low, so it can only be used for making newsprint.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] The hemp core stalk raw material is first cut into 3cm material sections with a bamboo cutter, and after screening, it is cooked and pulped by kraft method. The cooking conditions are: 19% alkali (Na 2 O meter), degree of sulfide 19% (Na 2 O meter), liquid ratio 1: 5, maximum temperature 150 ℃, heating time 120min, holding time 80min, pulp yield 49.3% after cooking, Kappa number 20, viscosity is greater than 1073ml / g; Gained pulp is washed and screened, and with double Oxygen delignification after dehydration in the wire press, adding NaOH, MgSO to the pulp 4 , EDTA, oxygen and H 2 o 2 etc. through the medium-consistency pump and the medium-consistency mixer and send them to the first upflow tower for hydrogen peroxide-enhanced oxygen delignification. The specific process conditions are NaOH dosage 3%, temperature 90°C, tower top pressure 0.7MPa, H 2 o 2 Dosage 1.2%, MgSO 4 The dosage is 0.2%, the dosage of EDTA is 0.3%, and the time is 30 minutes; the obtained pul...

Embodiment 2

[0020] The hemp core rod raw material is first cut into 2cm material sections with a bamboo cutter, and after screening, it adopts kraft cooking and pulping. The cooking conditions are: use 17% of alkali (Na 2 O meter), degree of sulfide 20% (Na 2 O meter), liquid ratio 1: 3, maximum temperature 160 ℃, heating time 120min, holding time 90min, pulp yield 48.8% after cooking, Kappa number 19, viscosity 1030ml / g; Paper pulp carries out oxygen delignification after washing and screening Su, hydrogen peroxide is used to strengthen oxygen delignification in the first upflow tower, and its technological conditions are NaOH dosage 2%, temperature 110°C, tower top pressure 0.5MPa, H 2 o 2 Dosage 1.0%, MgSO 4 The dosage is 0.3%, the dosage of EDTA is 0.1%, and the time is 40min; the process conditions of oxygen delignification in the second tower are NaOH dosage 1%, temperature 110℃, tower top pressure 0.3MPa, MgSO 4 The dosage is 0.2%, the time is 40min; the oxygen delignification r...

Embodiment 3

[0023] The raw material of the hemp core rod is first cut into 2cm material sections with a bamboo cutter, and after screening, adopts the sulfate method to cook and make pulp. The cooking conditions are: 19% (Na 2 O meter), degree of sulfide 20% (Na 2O meter), liquid ratio 1: 3, maximum temperature 155 ℃, heating time 100min, holding time 100min, pulp yield 49.0% after cooking, Kappa number 19, viscosity 1060ml / g; Paper pulp carries out oxygen delignification after washing and screening Su, hydrogen peroxide is used to strengthen oxygen delignification in the first upflow tower, and its process conditions are NaOH dosage 2%, temperature 105°C, tower top pressure 0.55MPa, H 2 o 2 Dosage 0.9%, MgSO 4 The dosage is 0.2%, the dosage of EDTA is 0.2%, and the time is 40min; the process conditions of oxygen delignification in the second tower are NaOH dosage 1%, temperature 105°C, tower top pressure 0.3MPa, MgSO 4 The dosage is 0.2%, the time is 35min; the oxygen delignification ...

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Abstract

The production process of bleached chemical pulp with hemp stalk core includes the following steps: 1. cutting hemp stalk core as material into 2-3 cm long sections, sieving and digesting in sulfate process to produce pulp; 2. washing and sieving the obtained pulp and oxygen delignifying; and 3. bleaching pulp with small amount of hypochlorite in a short program. Of the process, the medium concentration oxygen delignifying technology is one clean environment friendly bleaching technology with the bleached effluent being recovered and reused completely without environmental pollution, and the medium concentration hypochlorite bleaching can lower the exhausted waste water and reduce chemical and power consumption effectively. The pulp of the present invention can meet the requirement of making common paper.

Description

technical field [0001] The invention relates to pulping and papermaking engineering technology, in particular to a production method of hemp core rod bleached chemical pulp. Background technique [0002] my country's wood resources are scarce. In the annual consumption of pulp, only 21% is wood pulp, of which 16% is imported. Seeking non-wood fiber raw materials that can replace wood fiber in quality has always been a hot spot of concern. Hemp is a plant widely suitable for planting in my country. The bast fiber of hemp is an excellent textile raw material, so hemp is also commonly known as thread hemp. In the late 1980s, the Liaoning Paper Research Institute began research on hemp papermaking. In 1995, the research on the ultrastructure of cannabis was listed as a project funded by the Science and Technology Fund of Liaoning Province. In recent years, the World Hemp Center has set up a branch in Shenyang, and Shenyang Chengjiantong New Intelligence Company has established...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): D21B1/04D21C3/02D21C9/08D21C9/14
Inventor 陈克复莫立焕李军杨仁党陈奇峰
Owner SOUTH CHINA UNIV OF TECH
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