SU781241A1 - Method of obtaining fibrous semi-finished product - Google Patents

Description

1 The invention relates to pulp and paper industry, in particular to methods for producing semi-finished products of high yield from plant raw materials using side products of the cooking process. A known method for the production of hemicellulose from a mixture of coniferous and foliage wood is by means of bicutumous wood nJrl jt l v "j.- - - t; - - ki on a sodium base 1J. There is also known a method for bisulfite pulping of a fibrous semi-finished product using spent liquor to prepare a cooking solution after strengthening it with chemicals to the required content of sulfurous anhydride and base in solution, in which the issue of using chemicals from spent liquor is solved, regeneration is simplified, because The liquor is fed with a higher organic content liquor. The amount of waste liquor used for cooking the cooking liquor is limited by the yield of the semi-finished product. A disadvantage of the known method is the lack of a solution for the utilization of organic matter from the waste liquor lye. . The goal is achieved by the use of a post-yeast mash or its mixture with spent liquor at a ratio of 70: 80-20: 30 as the by-products when preparing the cooking liquor. The method is carried out as follows. Chips from a mixture of hardwood and coniferous wood are cooked with a solution, for which they use a post-dough mash or a mixture of it with spent liquor. The cooking solution is saturated with 50 and MDO is added to the desired content in the solution. Cooking is carried out for 2-3.5 hours at a pH of 3.8-4.8 and an ISO-Io C temperature. After cooking, the pulp is ground to 26-35 ° ShR and used in making base paper for corrugating and cardboard for smooth layers. Waste liquor from cooking is subjected to inversion, the wort is prepared and

it is processed into proteinaceous fodder yeast. A post-yeast brew is directed to the preparation of the cooking liquor, which significantly reduces power consumption for evaporation and eliminates the difficulties associated with the operation of evaporators.

Using brews and spent liquor to prepare cooking acid significantly reduces the need for fresh water, and the costs associated with wastewater treatment are reduced.

The post-fermentation brew after the processing of MD-isulfite liquor for yeast contains 7.5–11% of dry matter, P |) ranges from 6–8.5% of dry matter The organic part of the dry, the substance of the mash is mainly lignosulfonate magnesium, furfuro content 0 2-0.3%. The mineral portion of the mash is 22-23% of the total dry matter. The composition of the mineral part of the dry residue of the mash contains,%: Md 9.0–9.2 sulfur 10.6–10.5 and 30 about 30.

Due to the presence of organic matter in the mash-4, there is an increase in the yield of hemicellulose.

Example 1. Preparation of hemicellulose by the known magnesium bisulfite method.

Take deciduous chips 85%, ate 15%. 1 Cooking solution contains,%: total SOj 2.8, MgO 1.7.

pH - 4.5%; hydronic module of cooking 4: 1; Boiling is carried out at for 3 hours. The yield of hemicellulose is 67.1%, Kappa hardness is 70.2%. ; :. .

When the degree of grinding 30 SR and the mass of castings 100 g / m. hemicellulose has the following quality indicators:

Breaking length, m 6400 The number of double kinks 70 The resistance of push-off. now kg / cm 2

plane compression, kg / cm 3,2

Tear resistance

niyu g 94

The pH of the spent liquor is 4.7. Black liquor after a vacuum of 7.68% dry matter.

The composition of the dry residue,%: PB 18.1 /

 Organic acids 3.06 Furfural 0.82

Mineral substances 12.62, 58

Sulfur 6,57

Example 2. Preparation of hemicellulose according to the proposed method. The cooking solution contains 40% post-yeast brew. The composition of the cooking solution,%:

S022.85

MgO1 74

Serao; 408

RV: . - -о; ЗЗ Volatile acids 0,003 Furfurol0,011

Ash content 0.83%; The pH of the cooking solution is 4.2. five ; Take hardwood chips, 85%,

ate 15%. Cook at for 3 hours. The yield of hemicellulose is 68.5%; Kappa stiffness.

. When the degree of grinding and mass, Q casting 100 g / m hemicellulose has the following quality indicators: Breaking length, m 6800 The number of double pereg-. bov200

Bursting strength, -kg / cm ,, 3,4 Planar compression, kg / cm 3,2

Resistance to tearing, g 100 0 Processed G: liquor has the following characteristics:

Density, g / cm 3 1,034 PH. 4.5 Dry matter content,% 7.9

The composition of the dry residue,%: PB18,02

SOa4,3

.Sera6,7

Q Volatile organic

acids 3.04

Furf rl0,88

The ash content of the dry residue of 12.7%. 9 PRI m e r 3. To prepare the cooking solution, 100% mash is used.

The composition of the cooking solution,%: S042,85

MgO .1,8

Sulfur 1. 027

0 PB 0.84,

Furfurol0.027

Ash pH of cooking solution

85% of hardwood chips and 15% were eaten for cooking. The var is applied for 3 hours. The output of the cellulose is 70, l% f is Kapp hardness 75.

With the degree of grinding and mass of 0 casting 100 g / m, hemicellulose has the following quality indicators: Breaking length, m 6800 Number of DUAL kinks 300 Bursting resistance, kg / cm

Plane compression, kg / cm 3,7 Tearing, g100

The density of the composition of the spent liquor 1,035 g / cm; pH 4.4; dry matter content 8.0%. o Composition of solids liquor,%:

 PB 18.1

SOij.4,2

Sulfur 6,75

Claims (2)

Volatile organic acids 3.05 FurfurolO 85 Ash content of dry residue 12.9 Example 4. To prepare the cooking solution, use a 70% bleach mixture and 30% liquor. The composition of the cooking solution,% Furfural. Volatile acidity 1.8%; The pH of the cooking solution is 4.2. Cook a mixture of hardwood and wood chips at a temperature of 3 hours. The yield of hemicellulose is 72%; Kapp stiffness 76.5. When the degree of grinding and weight of the wok is 100 g / m, hemicellulose has l- -llLLUJlt S and MMtJe HVKttllMP Ltchlgtt .-.,. following quality indicators: Breaking length, m 6200 Number of double kinks110 Resistance to bursting, kg / cm g, 4 Plane compression, kg / cm 2 21 Bursting, g 94 Composition density worked out; liquor 1.035 pH 4.3; dry matter content 8.05%. The composition of the dry residue,%: Pb- 17.95 S02. 4.15 Sulfur 6.8 Volatile acids 3.1 Furfural 0.81 Ash content of dry residue 13%. The use of a post-yeast brew for cooking semi-cellulose or a mixture of it with waste liquor leads to a rise in the yield of the semi-finished product, apparently due to the adsorption of organic substances from the cooking solution on the fibers and an increase in the physicomechanical parameters. The consumption of chemicals for the preparation of the cooking liquor is reduced by 10–20% MdO, by 5–10% 50 d, which allows it to be used repeatedly and not discharged into water bodies. The invention of the method for producing a fibrous semi-finished product, including the preparation of a bisulfite solution on magnesium bases using cooking by-products, strengthening it with chemicals and subsequent cooking, differs in that, in order to increase the yield of the target product and reduce the pollution of the environment around it, when preparing the finishing solution as by-products, a post-yeast brew or its mixture with spent liquor is used at their ratio of 70:80 - 20:30. Sources of information, rintye in attention-with e.pertise 1. Proceedings of VNIIB, | Vol. 57, 1970,. 34 2. USSR author's certificate No. S58995, cl. D 21 3/06, 1973.