SU829747A1 - Cellulose pulp production method - Google Patents

Description

(54) METHOD OF OBTAINING CELLARS

cellulose with high strength properties while maintaining a high degree of delignification and yield.

Example 2 The type of wood used is birch wood chips. A distinctive feature of this series of boiling is a reduced consumption of alkali for boiling followed by oxidative treatment with peracetic acid. The technological parameters of the treatments and the quality of the pulp produced are presented in Table 2.

The results obtained in this series of experiments confirm the advantages of the proposed method. High yield pulp was obtained with NIKKIM lignin content and with high strength properties with a significantly lower consumption of peracetic acid. The pulp obtained (Examples 1 and 2) is suitable for the production of various types of paper.

Example 3. Cellulose obtained for various types of container

cardboard. Hardwood wood chips (birch and aspen) are pre-treated with water for 60 minutes, followed by alkaline treatment for 2 hours, semi-mass grinding and processing with peracetic acid at 70 ° C and consumption of 25% FROM absolutely dry fiber mass. . The quality indicators of the semi-finished product are presented in table 3.

The data (Table 3) shows that a semi-finished product of high yield of 69% was obtained with a deep degree of dalignification (lignin content of 2.5%). The strength of the semi-finished product is maintained at a high level.

The data in Tables 1, 2, and 3 show that the proposed method allows 20 to reduce the consumption of chemicals, while maintaining the high selectivity of the delignification process and the physicomechanical characteristics of the target product.

Wood type

Alkali consumption in units of Na-O,% by weight of absolutely dry wood

Peracetic acid consumption,% of absolutely dry fiber

The yield of cellulose,% Content of lignin,%

Physico-mechanical indicators of strength with the degree of grinding and the mass of the casting 75

Breaking length, m

Fracture resistance, the number of double 3000 bends

Table 1

Pine Birch Birch Birch

eleven

15

18

eleven

9370 10010 9800 9860

2900 2800 2500 2100

Alkaline treatment temperature, with

Duration of rise up to 16, min. Duration of standing, at 165 ° C, min. Alkali consumption in units of Na.,% By weight of absolutely dry wood. Oxidation treatment temperature, ° C. Duration of oxidative treatment, h. Peracetic acid consumption,% by weight of absolutely dry fiber. The yield of cellulose,% Content of lignin,% Physico-mechanical. indicators of strength with the degree of grinding and the mass of the casting 75. Breaking length, m 9600 9700 10050 Resistance to fracture, the number of double kinks 2400 2550 2750

table 2

165 165 165 165

95

90

90 90 90 105 105 105 6.0 6.0 10, 70 70 70 3.5 3.53, 101510 62.561.759, 5.0 4.85, 5 .. 18 0.0. 50 3.5 3.5 5 7.2 4.9 Not detected 11000 0 0

Type of wood Birch

The output of semi-finished products,% 68.6

The content of lignia,% 2,6

Physicomechanical indicators of strength with a degree of grinding of 60 ° SR and a mass of casting 75 g / m:

Discontinuous

length, m

Kink resistance, number of double kinks.

Claims (2)

1. A method of producing cellulose, which includes the operations of treating a cellulosic material with a radionic acid and an alkaline reagent, characterized in that, in order to reduce the consumption of chemicals while preserving the physicomechanical indicators of the target product and from the selectivity of the delignification process, the cellulose containing the material with an alkaline reagent Table 3 Aspen 50% Birch Birch Birch Cuts, 50% Aspen Birch 68.6 69.0 61.5 62.0 . 11.3 12.0 2.5 3460 9100 7360 9700 1700 1420 879 2500 carried out before the operation processing peracetic acid. 2. Method POP.1, characterized by the fact that treatment with an alkaline reagent is carried out at 10IBO C. Sources of information taken into account in the examination 1. US patent 3458394, cl. 162-76, 1969. 2. USSR author's certificate number 368364, cl. About 21 3/04 1971 (prototype) ..