SU958554A1 - Method of producing pulp for chemical processing - Google Patents

Description

During the process of preliminary hydrolysis and sulphate cooking using pine wood.

Example. A series of experiments was carried out to study the effect of the use of purified wastewater from the production of sulphate pulp during preliminary hydrolysis and the quality of the unbleached pulp obtained.

The results of the influence of the characteristics of the aquatic environment on the quality indicators of cellulose using different aqueous media on the preliminary hydrolysis are presented in Table. 2

For comparison, the experiment was carried out on distilled water. Except. the influence of other factors; cooking liquor for sulphate cooking is prepared in distilled water. Sulfide liquor - 25%.

The mode of preliminary hydrolysis: the hydromodule 1: 4, after filling the autoclave with water at 70 ° C, lifting is carried out up to 120 minutes, standing at 70 minutes. After the end of the hydrolysis, the prehydrolyzate is removed and the cooking liquor is pumped into the autoclave. Alkali consumption - 19% units. by weight of absolutely dry wood. Hydromodule 1: 4. Impregnation at 135 ° C - 30 minutes, rise from 135 to 170 ° C - 60 minutes, standing at 170 ° C - 90 minutes.

The main indicators obtained Unbleached pulp, as well as the content of the components of the ash residue are presented in table. 3

As the results of experiments 3, 4 and B show, the wastewater after biological, chemical and complete purification can successfully replace fresh water during preliminary hydrolysis. The resulting pulp meets all the requirements for quality and improves the degree of penetration.

Example 2. A series of experiments was carried out to study the effect of using wastewater on the production of sulphate pulp, different degrees of purification with sulphate varkey and the quality of the resulting pulp.

Preliminary hydrolysis in all experiments was carried out using distilled water to eliminate the influence of other factors on the quality of cellulose. Sulphate cooking liquor with a sulfide content of 25% is prepared on treated wastewater, similar to example 1. The conditions of pre-hydrolysis and sulphate cooking are the same as in example 1.

The results of the influence of the use of wastewater of different degrees of purification during sulphate cooking on the quality of unbleached pulp are presented in Table. 4.Dan table. 3 indicate the possibility of using this aqueous medium in the sulphate cooking process.

Example 3. A series of experiments was carried out using purified wastewater from the production of sulphate pulp; 1 pulp for both preliminary hydrolysis and sulphate cooking. The conditions of prehydrolysis and sulfate cooking are similar to Example 1.

Characteristics of treated wastewater from the production of sulphate pulp are presented in table. five.

The results of using wastewater from the production of sulphate pulp of different degrees of purification in the process of obtaining unbleached pulp are presented in Table. 6

The resulting pulp meets the quality requirements of unbleached pulp. This suggests the possible use of these waste waters in the process of obtaining unbleached pulp.

Example 4. At the pilot plant of the Baikal Pulp and Paper Mill, cellulose is obtained for chemical processing using the proposed method. Pine from the industrial stream is used as wood (see tab. one).

The data presented in table. 1 to 7 show that the proposed method for producing cellulose for chemical processing reduces the stiffness of cellulose, which contributes to the creation of an improved scheme of water use, reduces the consumption of fresh water.

Table

pH

Oxidability, mg / l

Alkalinity, mEq / l Chroma, ° PKSh

BOD, mg O, / l PDA, mg

Suspended substances, mg / l

Turpentine, mg / l

Dissolved oxygen, mg / l

Content, mg / l

Aromatic substances of phenol range, mg / l

50-270 3-201-10

0.02-0.5 0.02-0.30 0.02-0.3

2.5-7.55-8

350-500 560-700560-700

10-30

30-70

70-150

tf

about

in in

about in

r

t

N

n

IN

GO IN VO

O

CM

.1Л

f

About SL

M

tN

CM

CO

r "

"

t

n

CM N

CN

ABOUT

PM

ha

S

H about nj

EH

ABOUT

in

t o

sh

in about

VO Y |

TN mH

Ltd

about CSNI

fM

P

VO

-

p oo

VO

tg

(L

rH

state of emergency

about

00

about

VO 1L

VO

"

go)

go h

and

in

SP

N

Yu

with

1L

fO

about

yes yes with

VO

g "

MS

Yes

rH

P1L

eat

.about

Vd

VO

th ch

about

oo

go

hVD

Yes

oo

(S

r-t

with h:

3

t about

about

The yield of pulp,% by weight of absolutely dry wood

Hardness, cellulose, p, units

Viscosity, mPa.-s

Content of OL cellulose,%

Ash content

The content of the ash elements in the pulp, mg / kg

Table. four

34.7

34.6

34.5

34.7

PH

Oxidability, mg / l

Alkalinity, mEq / l

Chroma, ° PKSh BPKg, mg COD, mg Oh,

Suspended substances, mg / l

Dissolved mineral substances, mg / l

Aromatic substances, mg / l

T a b, l and c a 5

6 12

3 32

D

"EG S CH

nS

fH

4in

CTv

CN |

to

r o

(Tl

n

vo

u

0 l fO

t in

1L

(4 fO

M 04 o U

gn go

in about

m 00

vo a

about vo

H n

in in

CO

vo (A

o

CN

vo

G4 about

a r-l "

rH

vo

f

S 4

in

about

in o

in

“R

4 The formula of the invention A method of producing cellulose for chemical processing, including preliminary hydrolier wood heat in an aqueous medium and subsequent cooking of sulphate cooking liquor

Quality prehydrolyzate

in an aqueous medium at elevated temperature and pressure, characterized in that, in order to reduce the rigidity of cellulose, the content of an aqueous medium during the preliminary hydrolysis and cooking is 212,555,5542

burning aromatic compounds of fe-sources of information

A flat row of sewage water taken into account in the examination of the production of sulphate cellulose q kon- 1. Kosa G.S. Production by sulcentration of aromatic substances of 10-fata viscose pulp. M, 150 mg / l and salt content 350- Forest industry, 1966, 760 mg / l. 5s. 77-92.

Claims (1)

Table 7 Type of water used: during hydrolysis Known method The proposed method After a complete cleaning scheme After biological treatment After purification nomic ^chi-1 After a complete cleaning scheme Filtered biological treatment when cooking Lye cooked in filtered water Lye is cooked " After biological treatment After chemical cleaning After the complete cleaning scheme pH 3.6 3.6 RV, "· 2.5 2.0 Oxidation, mg 0. / L 54,000 48000 Consumption of active Na ^ O of the mass of absolutely dry Wood in units On ^ o 15.0 15.0 The rigidity of cellulose, p. 115 117 Viscosity 1% m.a. MPa solution> s 49.5 54.6 The content of aL-cellulose,% 95.7 95.8 Ash content,% 0.55 0.60 The content of ash elements in cellulose; mg mg / kg. 'Fe thirty 59 Al 35 38 Μη 35 38 9 SI 391 378 Ca 1232 1152 Cii 17 eleven 165 162 • g Oxidation rate mg Q ^ / L 150,000 152000 ——> m Claims ^w A method of producing cellulose for chemical processing, including preliminary hydrolysis of wood chips in an aqueous medium and subsequent cooking with sulphate cooking liquor Prehydrolyzate Quality 3.6, 3.6 3.6 3.6 2, 4 2.0 2.5 2,4 45000 - 70400 - Sulphate Cooking 15.0 15.0 15.0 15.0 110 117 118 113 57.2 57.2 50.9 56.6 95.5 96.0 95.7 95.6 0.64 0.56 0.58 0.55 32 thirty 46 fifteen. 34 10 fifteen 9 38 twenty twenty 24 403 213 278 275 338 1378 1427 1447 17 12 fifteen eleven 205 146 157 182 Black liquor 176000 220,000 176000 152000 in an aqueous medium at elevated temperature and pressure, characterized in that, in order to reduce the rigidity of cellulose, the content of water during preliminary hydrolysis and cooking is used Wastewater from aromatic compounds of the phenolic series from sulphate pulp production q with a concentration of aromatic substances of 10150 mg / l and a salinity of 350,760 mg / l.