SU1624024A1 - Method of preparing spent sulphite cellulose lye for biochemical processing - Google Patents

Abstract

The invention relates to the pulp and paper industry and relates to methods for the disposal of waste liquor (OS) produced in sulphate pulp production. The purpose of the invention is to intensify the process of preparing the BS to biochemical processing and increase the yield of alcohol and yeast. At one of the stages of its preparation for biochemical processing, sodium sulfide is introduced into the liquor in an amount of 0.001-0.05 mash. on 100 ma.ch. liquor. It is proposed to introduce sodium sulfide before separating or in the process of separating the liquor from the cellulose, before, during or after refining, after the neutralization stage with air blowing or keeping 0.08-4 h. The source of sodium sulfide is green or white liquor sulfate pulp production. 1 hp f-ly, 2 tab. yo

Description

The invention relates to the pulp and paper industry and relates to methods for the disposal of waste liquor (OS) produced in sulphate pulp production.

The purpose of the invention is to intensify the process of preparing the BS to biochemical processing (BHP) and increase the yield of alcohol and yeast.

Silk is separated from cellulose after welding, and it is refined, neutralized, cooled and nutrient salts are introduced into it, as well as sodium sulfide (CH) in an amount of 0.001-0.05 wt.h. on May 100th. including purified lye (OSH).

Sodium sulphide is introduced into the liquor as an aqueous solution or sodium sulphide source is added - green or white liquor of the sulphate-pulp production at one of its preparation stages (except for the stage of cooling and the introduction of nutrient salts) h

Example 1. To 300 g of a 10% suspension of cellulose (30 g of cellulose in terms of a.s.m., the rest is sulphite liquor) at 90 ° C, sodium sulphide is added as a 3% solution ( 2.7 ml) at the rate of 0.03 mas. on 100 ma.ch. liquor, stirred, the liquor is separated from the cellulose in a Buchner funnel under vacuum and the pulp is washed with 90 ml of hot water, and the washing water is added to the BS. The liquor obtained has the following characteristics: a density of 1050 kg / m3, pH 3.0, a solids content of 10.5%, ash — 16.4% of solids, the content of directly titrated (n / t) CO2: 0.06 % easily ground (l / o) SO2 - 0.330%, reducing substances (PB) O

1CE

 about

1CE

4b.

2.7%, volatile acids - 0.25%, furfural - 0.07%.

One part of the liquor (100 ml) was blown with steam at 102 ° C for 30 minutes, neutralized with a 25% ammonia solution until pH 4.4 was cooled to 30 ° C, diluted with water to a PB concentration of 1.5% and nutrient injected. salts: ammophos (2.5% of PB by PaOs), potassium chloride (2.5% of PB) and ammonium sulfate (4% of PB by nitrogen).

Prepared for biochemical processing, the BS was adjusted to pH 6.0 with sodium hydroxide before growing the yeast and poured into 50 ml growth flasks. As a seed yeast using yeast concentrate containing 502 g / l of pressed yeast. Growing is carried out on a rocking chair at 35 ° C for 18 hours. Abs yield. dry yeast (ASD) of total PB, taken for cultivation, is 30.9%, the content of true protein is 45.4%.

Another part of the liquor (100 ml) was purged with air at 85 ° C for 1 hour. Further preparation for growing the yeast was carried out as described. The yield of ASD from total PBs is 31.5%, the true protein content is 45.7%.

By the proposed method, the yield of yeast increased by 7.6-9.8% compared with the known.

Example 2. 300 ml of lye are refined by evaporation at boiling 1.5 times (up to 200 ml), a solution of sodium sulfide is added at the rate of 0.036 wt.h. sulphide per 100 wt.h. liquor, incubated for 1 h at 80 ° C and cooled to 30 ° C. As a sulphide-containing solution, green liquor is used in sulphate-pulp production, which contains, g / l. NaOH 17; No. 28 32; Na2C03 99; Na2S04 5.

In the green liquor enough alkaline reagents, providing neutralization. After preparation, sulphite liquor contains 3.97% PB, pH 4.45. Biogenic additives are introduced into it: ammonium sulfate in the form of a 1.2% (nitrogen) solution (0.3 ml) and a solution of ammophos (1 ml) with a concentration of 1.2% by Pads. For fermentation, yeasts of the genus Saccharomyces are used, which are added at the rate of 2 g of compressed yeast per 100 ml of prepared wort. The flasks are placed in an air thermostat and incubated for 12 hours at 34 ° C. The alcohol concentration in the mash is determined by the flotation method and the alcohol yield per 100 kg of fermented PB is calculated.

The data obtained are presented in Table. one.

Compared with the known method, at a higher fermentation rate and a higher alcohol yield, the proposed method simplifies the technological scheme, where the stages of blowing through steam and air are excluded.

Example 3. 900 ml of sulphite liquor are taken, refined - blown with steam at 102 ° C for 30 minutes, adjusted

0 volume to the original and divided into 9 parts, in 8 parts of 100 ml at 85 ° C add sodium sulfide at the rate of 0.02 wt.h. per 100 wt.h. liquor. Green is used as a sulphide-containing solution.

5 liquors, the analyzes of which are given in Example 2. One sample immediately after the addition of sodium sulfide is cooled to 30 ° C, seven samples are kept at 85 ° C for 0.08-6 hours, then cooled to 30 ° C, the ninth

Part 0 is prepared by a known method. The pH of all samples after preparation in the range of 4.3-4.4. Further preparation and cultivation are carried out according to example 1.

The findings are presented in

5 tab. 2

The output of the ASD in the preparation of liquor by a known method of 31.3%.

From Table 2, it can be seen that the positive effect is obtained by keeping the liquor

0 after the addition of sulfide 0.08-2 hours

Example 4. 200 ml of sulphite liquor are taken and neutralized at 85 ° C with 25% ammonia solution to pH 5, after which sodium sulphide is added as 3%

5 solution at the rate of 0.015 wt.h. by May 100 h. lye and divided into two parts. One part (100 ml) was kept in a thermostat at 80 ° C for 2 h, the other was blown with air at 80 ° C for 2 h, then both parts were prepared for growth and carried out as in Example 1. The output of the SDA at shutter speed 36, 0%, with an air purge of 37.1%.

The yield during the preparation of the proposed method increased by 13.6-17.0%.

5 Yeast yield from the system under preparation

it to BHP on the proposed method is higher compared with the known 1.7-18%.

The proposed method leads to the intensification of BHP (for example, the process

0 fermentation) and simplifies its preparation. Thus, in example 4, two operations are excluded — steam blowing and air blowing.

All the advantages are due to the fact that HF is introduced into the system.

five

Claims (2)

Claim 1. Method for preparing spent liquor of sulphite pulp production for biochemical processing to produce alcohol and yeast comprising the steps of separating the liquor from cellulose, refining, neutralizing, cooling and introducing nutritional salts, characterized in that. in order to intensify the process and increase the yield of alcohol and yeast, into the liquor before or after separation of the liquor from cellulose, refining, Sodium sulphide in the amount of 0.001-0.05 wt. on 100 ma.ch. liquor and incubated for 0.08-2 hours 2. A method according to claim 1, characterized in that the sodium sulfide is introduced by adding green or white liquor from the sulphate-pulp production. Table 1 table 2