CN103790057B

CN103790057B - To the method for wood chip hot-water pretreatment and the pulping process utilizing the method before a kind of preparative chemistry mechanical pulp

Info

Publication number: CN103790057B
Application number: CN201410039664.9A
Authority: CN
Inventors: 侯庆喜; 刘苇
Original assignee: Tianjin University of Science and Technology
Current assignee: Tianjin University of Science and Technology
Priority date: 2014-01-27
Filing date: 2014-01-27
Publication date: 2016-03-30
Anticipated expiration: 2034-01-27
Also published as: CN103790057A

Abstract

The present invention relates to a kind of front method to wood chip hot-water pretreatment of preparative chemistry mechanical pulp, step is as follows: after chip impregnation, carries out screw extrusion; In the wood chip after screw extrusion process, adding water, the mixture of wood chip and water being carried out from being hydrolyzed preliminary treatment, obtain pre-hydrolyzed solution after process and be certainly hydrolyzed pretreated wood chip; Collect the wood chip after extruding as the raw material of reducing rules, obtain the wood chip after hot-water pretreatment.Preprocess method of the present invention make use of existing equipment component in pulp industry fully and does not need additional complexity equipment investment, only need to use water, a small amount of diluted acid and ethanol, and do not need to buy other chemicals, pretreating process can be completed, save comprehensive production cost significantly, be also conducive to existing enterprise by pulping and paper-making and biorefinery effective integration simultaneously.

Description

To the method for wood chip hot-water pretreatment and the pulping process utilizing the method before a kind of preparative chemistry mechanical pulp

Technical field

The invention belongs to the technical field of pulping and paper-making and biomass resource utilization, the method to wood chip hot-water pretreatment before especially a kind of preparative chemistry mechanical pulp, that is from hydrolysis process, and utilize the pulping process of the method.

Background technology

Living beings are inexhaustible, nexhaustible renewable resources the abundantest on the earth; it is the fourth-largest energy and material earth being only second to coal, oil and natural gas resource; annual output reaches 1,700 hundred million tons, and these abundant biomass resources have great importance to the sustainable development realizing World Economics, effective utilization of realizing environmental protection and resource.If pulp and paper industry can utilize biomass resource well, while production paper pulp, its residue can also be converted into the material of high added value, chemicals and fuel etc., this will extremely be conducive to the sustainable development of pulp and paper industry.

Lignocellulose raw material, as a kind of important biomass resource of occurring in nature and the important raw and processed materials of pulp and paper industry, its preliminary treatment is extracted and reclaim hemicellulose and is translated into the important prerequisite of biomass energy or high value added product, is also one of important technology route of changing towards " compound forest biomass rendering industry " of existing enterprises in pulp and paper industry.Research finds, in soda pulping process digestion process, most of hemicellulose has all been dissolved in black liquor, if sent into, chemical recovery system is concentrated, burning, will cause the waste of hemicellulose resource.So extract appropriate hemicellulose before slurrying, and transformed high-valued product and will bring extra income, its income is also far longer than the income of being burnt and producing, because the combustion heat value of hemicellulose is only only the half of lignin.In recent years, with CTMP (CTMP), bleached chemical thermomechanical pulp (BCTMP), Alkaline Peroxide Mechanical Pulp (APMP) and preliminary treatment add chemical-mechanical pulping (being also the called high yield cooking) technique that the chemically treated Alkaline Peroxide Mechanical Pulp of mill (P-RCAPMP) is representative, and because its pulping yield is high, wood consumption is little, in waste liquid, the low and common concern achieving obtaining paper industry of pollutant burden develops fast.The demand of high-yield pulp presents ever-increasing trend.In chemi-mechanical pulp pulping process, the hemicellulose of stripping can reach about 15%.Along with the stripping of hemicellulose, the materials such as some anionic trashes (DCS) also can constantly accumulate, and the continuous enrichment along with the closed circulation of water system, and then affect the production process of papermaking, change and paper machine operation stability as caused wet end of machine chemical property, also will increase pulping waste liquor load simultaneously, increase treatment cost of waste liquor.Therefore, before slurrying, preextraction part hemicellulose can not only make full use of hemicellulose resource, the chemicals usage in pulping process and energy consumption can also be reduced, reduce waste liquor contamination load and processing cost thereof, also contribute to solving some problems in the paper machine operation process caused due to paper pulp simultaneously.

By retrieval, find one section of following patent publication us relevant to patent application of the present invention:

APMP technology of preparing (CN1554827), relates to the technology that a kind of plant fiber material prepares APMP.This technical matters flow process comprises: wood chip, and---------------------disappear latent mill defibrination reaction warehouse one section of double helix fiberizer decatize---screening purification---concentrating---paper pulp for thermokalite or hot-water pretreatment in washing.The pulping bleaching technology of this technology is: by the concentration that the prepares H at 5 – 10% ₂o ₂the aqueous solution, adds H ₂o ₂in basin; By NaOH, Na ₂siO ₃be made into concentration 5 – 10% mixed liquor with water, add in another basin.First remerging through two pipelines with two measuring pumps is respectively a pipeline, and the medicine feeding hole on double helix fiberizer, quantitatively injects in this machine continuously by final admixing medical solutions, makes material produce chemical reaction in casing, and discharging alkali lye can soften material.Owing to instead of press screw and impregnator, save the energy, save floor space.

By contrast, there is essential distinction in the invention in the present invention and document, the present invention is by being certainly hydrolyzed preliminary treatment to reach the object extracting a part of hemicellulose, a certain amount of acetic acid and a small amount of lignin, and the wood chip after being certainly hydrolyzed still carries out manufacture and the production of reducing rules, the materials such as hemicellulose, lignin and acetic acid can not only be obtained by such process, obtain reducing rules product, also can reduce refining energy consumption simultaneously, improve the performance of part size; And the content in document is just protected for the pulping process of certain limit, therefore, there are the different of essence in patent application of the present invention and above-mentioned patent publication us.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art part, there is provided a kind of method simple, easy to operate, reduce the consumption of the energy, save comprehensive production cost significantly, also be conducive to existing enterprise by pulping and paper-making and biorefinery effective integration simultaneously, reduce chemi-mechanical pulp refining energy consumption, reduce the front method to wood chip hot-water pretreatment of preparative chemistry mechanical pulp that follow-up pulping waste liquor pollutes and the pulping process and the papermaking process that utilize the method.

To achieve these goals, technical scheme of the present invention is as follows:

A method to wood chip hot-water pretreatment before preparative chemistry mechanical pulp, step is as follows:

(1) hot water wood chip being placed in 80 – 100 DEG C soaks 20 – 40 minutes, then the wood chip of hot-water soak is carried out screw extrusion, and the compression ratio of screw extrusion is 3:1 – 5:1;

(2) in the wood chip after screw extrusion process, add water, the absolute dry mass of wood chip is made to be 1:4 – 1:10 with adding the total liquid volume after water than kg:L, the mixture of wood chip and water is carried out from being hydrolyzed preliminary treatment, from the pretreated condition of hydrolysis be: the heating-up time controls 20 – 60 minutes, boiling temperature is 110 – 180 DEG C, temperature retention time is 10 – 60 minutes, obtains pre-hydrolyzed solution and be certainly hydrolyzed pretreated wood chip after process;

(3) pre-hydrolyzed solution is extracted out, store as dense extract; Wash from the pretreated wood chip clear water of hydrolysis, and be placed in screw extruder and extrude, the compression ratio of screw extruder is 3:1 – 5:1, collect the filtrate after washing and after again extruding, as rare extract after mixing, be then incorporated to dense extract and be mixed to get extract, store for subsequent use; Collect the wood chip after extruding as the raw material of reducing rules, obtain the wood chip after hot-water pretreatment, for subsequent use;

(4) the extract collected is carried out evaporation and concentration in the temperature range of 45 – 65 DEG C, till the 15-50% of former extract concentration, recycling mass concentration be 3.0% diluted acid adjust ph be that 2.0 – 2.5 are to precipitate lignin, then centrifuging treatment is carried out, centrifugal condition is: centrifuge speed 5000 – 8000 revs/min, centrifugation time 10 – 30 minutes, temperature 20 – 30 DEG C;

After centrifuging treatment, collect supernatant liquor part and sediment fraction respectively, carry out following process:

1. for supernatant liquor part, doubly join in supernatant liquor to the ethanol of supernatant liquor volume by 2 – 4, then carry out centrifuging treatment to precipitate hemicellulose class material, centrifugal condition is: centrifuge speed 5000 – 8000 revs/min, centrifugation time 10 – 30 minutes, temperature 20 – 30 DEG C; After centrifuging treatment terminates, collect the ethanol in supernatant liquor, to recycle; Collect the precipitation formed in centrifugal process, will precipitate through washing, abstraction and purification, and at 45 – 60 DEG C after drying, the hemicellulose base product with high added value produced and develop must be can be used for;

2. by step (4) in sediment fraction mass concentration be 3.0% diluted acid adjust ph to 2.0 – 2.5, after centrifuging treatment, centrifugal condition is: centrifuge speed 5000 – 8000 revs/min, centrifugation time 10 – 30 minutes, temperature 20 – 30 DEG C, the sediment fraction obtained is acid-insoluble lignin, collects this part lignin for subsequent production and exploitation lignin base product.

And the length and width of described wood chip are of a size of 10 – 30mm, thickness is 3 – 6mm.

And, described step (4) in mass concentration be 3.0% diluted acid be sulfuric acid or hydrochloric acid.

Utilize the front pulping process to the method for wood chip hot-water pretreatment of preparative chemistry mechanical pulp as above, step is as follows:

(2) in the wood chip after screw extrusion process, add water, the absolute dry mass of wood chip is made to be 1:4 – 1:10 with adding the total liquid volume after water than kg:L, the mixture of wood chip and water is carried out from being hydrolyzed preliminary treatment, from the pretreated condition of hydrolysis be, heating-up time controls 20 – 60 minutes, boiling temperature is 110 – 180 DEG C, and temperature retention time is 10 – 60 minutes, obtains pre-hydrolyzed solution and be certainly hydrolyzed pretreated wood chip after process;

(3) pre-hydrolyzed solution is extracted out, store as dense extract; Wash from the pretreated wood chip clear water of hydrolysis, and be placed in screw extruder and extrude, the compression ratio of screw extruder is 3:1 – 5:1, collect the filtrate after washing and after again extruding, as rare extract after mixing, be then incorporated to dense extract and be mixed to get extract, store for subsequent use; Wood chip after extruding delivers to slurrying workshop section as the raw material of reducing rules, for subsequent use;

(4) the extract collected is carried out evaporation and concentration in the temperature range of 45 – 65 DEG C, till 15 – 50% of former extract concentration, recycling mass concentration be 3.0% diluted acid adjust ph be that 2.0 – 2.5 are to precipitate lignin, then centrifuging treatment is carried out, centrifugal condition is: centrifuge speed 5000 – 8000 revs/min, centrifugation time 10 – 30 minutes, temperature 20 – 30 DEG C;

2. by step (4) in sediment fraction mass concentration be 3.0% diluted acid adjust ph to 2.0 – 2.5, after centrifuging treatment, centrifugal condition is: centrifuge speed 5000 – 8000 revs/min, centrifugation time 10 – 30 minutes, temperature 20 – 30 DEG C, the sediment fraction obtained is acid-insoluble lignin, collects this part lignin for subsequent production and exploitation lignin base product;

By step (3) described in the wood chip after hot-water pretreatment deliver to the slurrying of reducing rules slurrying workshop section, the step of the Chemical impregnation of slurrying is as follows:

For preparative chemistry thermomechanical pulp, in Chemical impregnation process, add NaOH, metal ion chelation agent, H ₂o ₂or Na ₂sO ₃, the addition of NaOH for step (3) described in the 1-7% of OD wood chip quality of wood chip after hot-water pretreatment, the addition of metal ion chelation agent for step (3) described in the 0.1-0.3% of OD wood chip quality of wood chip after hot-water pretreatment, H ₂o ₂addition for step (3) described in the 1-7% of OD wood chip quality of wood chip after hot-water pretreatment, or Na ₂sO ₃addition for step (3) described in the 1-4% of OD wood chip quality of wood chip after hot-water pretreatment;

The treatment temperature of this Chemical impregnation is 60 – 100 DEG C, and processing time 10 – 40 minutes, obtains the wood chip after Chemical impregnation process;

By step (5) described in the wood chip through Chemical impregnation process carry out two sections of grinding process: first paragraph is pressure grinding, actual conditions is: temperature 120 – 170 DEG C, pressure 0.1 – 0.7MPa, mass concentration during grinding is 10% – 30%, grinding 2 – 7 minutes; Second segment is normal pressure grinding, and actual conditions is: disk mill gap 0.08 – 0.10mm, and mass concentration 5% – 30% of slurry, obtains the lumber fibre slurry after grinding after two sections of grinding process;

By step (6) in lumber fibre slurry be placed in eliminating potential pool and process, condition is: the mass percent 4.0% of slurry, water temperature 80 – 95 DEG C, time 20 – 40 minutes, by the pulp screen enterprising row filter of the slurry after diving at the wide 0.10 – 0.15mm of seam that disappear, the mass concentration of then dewatering to slurry is 15 – 30%, obtains slurry finished product.

And described step (5) middle metal ion chelation agent is DTPA or EDTA.

For preparing bleached chemical thermomechanical pulp, in Chemical impregnation process, add NaOH, metal ion chelation agent, H ₂o ₂or Na ₂sO ₃, the addition of NaOH for step (3) described in 1 – 7% of OD wood chip quality of wood chip after hot-water pretreatment, the addition of metal ion chelation agent for step (3) described in the 0.1-0.3% of OD wood chip quality of wood chip after hot-water pretreatment, H ₂o ₂addition for step (3) described in 1 – 7% of OD wood chip quality of wood chip after hot-water pretreatment, or Na ₂sO ₃addition for step (3) described in 1 – 4% of OD wood chip quality of wood chip after hot-water pretreatment;

By step (5) described in the wood chip through Chemical impregnation process carry out two sections of grinding process: first paragraph is pressure grinding, actual conditions is: temperature 120 – 170 DEG C, pressure 0.1 – 0.7MPa, grinding 2 – 7 minutes, mass concentration during grinding is 10% – 30%; Second segment is normal pressure grinding, and actual conditions is: disk mill gap 0.08 – 0.10mm, and mass concentration 5% – 30% of slurry, obtains the lumber fibre slurry after grinding after two sections of grinding process;

(7) blanching step, in bleaching process, alkali charge be step (7) in the NaOH of slurry oven dry weight 2.0 – 6.0% that obtains, the diethylene triamine pentacetic acid (DTPA) of slurry oven dry weight 0.1 – 0.3% is water-soluble, the ratio kg:L of NaOH and water used, and the ratio kg:L of diethylene triamine pentacetic acid (DTPA) and water used is 1:3, to be then distributed in slurry and full and uniform mixing; Add subsequently step (7) in the hydrogen peroxide of sodium metasilicate and 2.0 – 8.0% of slurry oven dry weight 1.0 – 3.0% and the mixed liquor of the water that need additionally add, wherein, the ratio kg:L of sodium metasilicate and water used, and the ratio kg:L of hydrogen peroxide and water used is 1:3, the mass concentration of slurry in bleach system is made to be 10-35%, rapid stirring slurry makes it mix, and then carries out bleaching action; The actual conditions of bleaching action is: temperature 60 – 90 DEG C, time 100 – 160 minutes, mixing speed 300 – 1000 revs/min; After bleaching action terminates, the slurry with water after bleaching is fully washed, and regulates slurry pH value to be about 5.0, disposed slurry finished product must be bleached.

And described step (5) middle metal ion chelation agent is DTPA or EDTA.

(4) the extract collected is carried out evaporation and concentration in the temperature range of 45 – 65 DEG C, till the 15-50% of former extract concentration, recycling mass concentration be 3.0% diluted acid adjust ph be that 2.0 – 2.5 are to precipitate lignin, then centrifuging treatment is carried out, centrifugal condition is: centrifuge speed 5000 – 8000 revs/min, centrifugation time 10 – 30 minutes, temperature 20-30 DEG C;

By step (3) described in the wood chip after hot-water pretreatment deliver to the slurrying of reducing rules slurrying workshop section;

(6) wood chip enters presteaming storehouse and carries out decatize, and presteaming condition is: 90 – 95 DEG C, the time of staying 3 – 10 minutes; Subsequently by first paragraph screw press pre-preg device, the pre-preg time is 1 – 8 minutes; The compression ratio of screw press is 4:1 – 6:1; In Chemical impregnation process, add NaOH, metal ion chelation agent, sodium metasilicate and H ₂o ₂the addition of NaOH for step (5) described in 1 – 8% of OD wood chip quality of wood chip after hot-water pretreatment, the addition of metal ion chelation agent for step (5) described in 0.1 – 0.5% of OD wood chip quality of wood chip after hot-water pretreatment, the addition of sodium metasilicate for step (5) described in 0.5 – 3.0%, H of OD wood chip quality of wood chip after hot-water pretreatment ₂o ₂addition for step (5) described in 1 – 7% of OD wood chip quality of wood chip after hot-water pretreatment; The treatment temperature of this Chemical impregnation is 60 – 90 DEG C, and processing time 10 – 40 minutes, obtains the wood chip after Chemical impregnation process;

(7) the wood chip after first paragraph pre-preg process, carry out second normal pressure and steam storehouse reaction in advance, presteaming condition is: 90 – 95 DEG C, the time of staying 3 – 10 minutes, obtain the wood chip after second segment pre-preg process;

(8), by reaction warehouse material out, enter second segment screw press macerator; In Chemical impregnation process, add NaOH, metal ion chelation agent, sodium metasilicate and H ₂o ₂the addition of NaOH be step (7) in 1 – 8% of OD wood chip quality of wood chip after second segment pre-preg process, the addition of metal ion chelation agent be step (7) in 0.1 – 0.5% of OD wood chip quality of wood chip after second segment pre-preg process, the addition of sodium metasilicate be step (7) in 0.5 – 3.0%, H of OD wood chip quality of wood chip after second segment pre-preg process ₂o ₂addition be step (7) in 1 – 7% of OD wood chip quality of wood chip after second segment pre-preg process; The treatment temperature of this Chemical impregnation is 60 – 90 DEG C, and processing time 10 – 60 minutes, obtains the wood chip after Chemical impregnation process;

(9) the wood chip after second segment pre-preg enters the 3rd normal pressure and steams storehouse in advance, and continue logical vapour and carry out chemical reaction, reaction condition is: 90 – 95 DEG C, the time of staying 3 – 10 minutes;

(10) send into first paragraph fiberizer subsequently, carry out atmospheric refining runs, after mill after thick slurry dilution, enter second segment fiberizer and carry out atmospheric refining runs again; The refining concentration of first paragraph mill is 15-35%, and the refining concentration of second segment mill is 10 – 20%, obtains lumber fibre slurry;

By step (10) in lumber fibre slurry be placed in eliminating potential pool and process, condition is: mass percent 3.0 – 4.0% of slurry, water temperature 70 – 95 DEG C, time 20 – 40 minutes, by the pulp screen enterprising row filter of the slurry after diving at the wide 0.10 – 0.15mm of seam that disappear, the mass concentration of then dewatering to slurry is 15 – 30%, obtains slurry finished product.

And, described step (6) and (8) in metal ion chelation agent be DTPA or EDTA.

(6) wood chip enters presteaming storehouse and carries out decatize, and presteaming condition is: 90 – 95 DEG C, the time of staying 3 – 10 minutes; Subsequently by first paragraph screw press pre-preg device, the pre-preg time is 1 – 8 minutes; The compression ratio of screw press is 4:1 – 6:1; In Chemical impregnation process, add NaOH, metal ion chelation agent, sodium metasilicate and H ₂o ₂, the addition of NaOH for step (5) described in the 1-8% of OD wood chip quality of wood chip after hot-water pretreatment, the addition of metal ion chelation agent is 0.1 – 0.5% of OD wood chip quality, and the addition of sodium metasilicate is 0.5 – 3.0%, H of OD wood chip quality ₂o ₂addition be 1 – 7% of OD wood chip quality; The treatment temperature of this Chemical impregnation is 60 – 90 DEG C, and processing time 10 – 40 minutes, obtains the wood chip after Chemical impregnation process;

(8), by reaction warehouse material out, enter second segment screw press macerator; In Chemical impregnation process, add NaOH, metal ion chelation agent, sodium metasilicate and H ₂o ₂the addition of NaOH be step (7) in 1 – 8% of OD wood chip quality of wood chip after second segment pre-preg process, the addition of metal ion chelation agent be step (7) in 0.1 – 0.5% of OD wood chip quality of wood chip after second segment pre-preg process, the addition of sodium metasilicate be step (7) in 0.5 – 3.0%, H of OD wood chip quality of wood chip after second segment pre-preg process ₂o ₂addition be step (7) in the 1-7% of OD wood chip quality of wood chip after second segment pre-preg process; The treatment temperature of this Chemical impregnation is 60 – 90 DEG C, and processing time 10 – 60 minutes, obtains the wood chip after Chemical impregnation process;

(9) the wood chip after second segment pre-preg enters sends into first paragraph fiberizer, and carry out atmospheric refining runs, refining concentration is 15 – 35%, obtains the wood chip through first paragraph grinding;

By above-mentioned steps (9) in be placed in high density hypo tower through the wood chip of first paragraph grinding and react, reaction condition is: temperature 80-95 DEG C, stock quality concentration 20 – 35%, the time of staying 60 – 180 minutes;

(11) send into second segment fiberizer subsequently through the too high dense slurry stopping reaction, carry out atmospheric refining runs, refining concentration is 10-20%;

Advantage of the present invention and good effect are:

1, preprocess method method of the present invention is simple, easy to operate, the hydrolysis wood chip yield prepared is up to 96.9%, make use of existing equipment component in pulp industry fully and do not need additional complexity equipment investment, only need to use water, a small amount of diluted acid and ethanol, and do not need to buy other chemicals, pretreating process can be completed, reduce the consumption of the energy and comprehensive production cost, also be conducive to existing enterprise by pulping and paper-making and biorefinery effective integration simultaneously, reduce chemi-mechanical pulp refining energy consumption, reduce follow-up pulping waste liquor and pollute.

2, preprocess method of the present invention can not only obtain the material such as a certain amount of hemicellulose and lignin class, can also ensure that follow-up slurrying is produced, improve the efficient of wood fiber biomass resource and higher value application, the refining energy consumption such as reducing subsequent chemical mechanical slurrying can also be brought by this preprocess method, alleviate the advantages such as the accumulation problem of dissolving and colloidal type material.

3, pulping process processing ease of the present invention, method is easy, with low cost, preparation-obtained slurry with without from being hydrolyzed compared with pretreated pulping process flow, the pressurized refining part of this pulping process and beating energy consumption are saved up to 23.1% and 38.7% respectively; The sheet pulp physical properties of slurry of the present invention is respectively: bulk is 2.34 – 2.54cm ³/ g, tensile index is 13.5 – 17.4Nm/g, and tear index is 1.58 – 1.83mNm ²/ g, ISO whiteness is 42.4 – 63.3%, and opacity is 90.6 – 96.9%, and light scattering coefficient is 39 – 43m ²/ kg, the absorption coefficient of light is 0.6 – 2.5m ²/ kg; With without from being hydrolyzed compared with pretreated slurry, the bulk of slurry of the present invention reduces by 6.3 – 9.1%, tensile index increases by 17.8 – 28.9%, tear index reduces by 3.1 – 22.7%, ISO whiteness reduces by 19.1 – 33.0%, opacity improves 5.7 – 7.0%, light scattering coefficient improves 2.4 – 7.1%, and the absorption coefficient of light improves 133.3 – 316.7%.

Detailed description of the invention

Below in conjunction with embodiment, the present invention is further described; Following embodiment is illustrative, is not determinate, can not limit protection scope of the present invention with following embodiment.

The method used in the present invention, if no special instructions, is the conventional method of this area; The reagent used in the present invention, if no special instructions, is the conventional reagent of this area; Each raw material relative content in the present invention is weight percentage.

The present invention at chemi-mechanical pulp (as wealthy wooden chemistry mechanical pulp, main finger CTMP (CTMP), bleached chemical thermomechanical pulp (BCTMP), Alkaline Peroxide Mechanical Pulp (APMP) and preliminary treatment add the chemically treated Alkaline Peroxide Mechanical Pulp of mill (P-RCAPMP)) before slurrying, first utilize from hydrolysis preliminary treatment Extraction parts hemicellulose and lignin, the wood chip after extraction is for the preparation of chemi-mechanical pulp.The present invention is intended to realize the efficient of living beings and higher value application, reduces chemi-mechanical pulp refining energy consumption, reduces follow-up pulping waste liquor and pollutes.

Embodiment 1

(1) (length and width size is between 10 – 30mm from the wood chip obtained, to screen the wood chip of size qualification, thickness is between 3 – 6mm), hot water wood chip after screening being placed in 90 DEG C soaks 30 minutes, and then the wood chip of hot-water soak is carried out screw extrusion, the compression ratio of screw extrusion is 4:1;

(2) in the wood chip after screw extrusion process, add water, make the absolute dry mass of wood chip and add the total liquid volume after water than being 1:4(kg:L), the mixture of wood chip and water is placed in boiling vessel or pressure vessel carries out from being hydrolyzed preliminary treatment, in digestion process, the heating-up time controls at 30 minutes, boiling temperature is 140 DEG C, and temperature retention time is 30 minutes;

(3) the pre-hydrolyzed solution in digester or pressure vessel is extracted out, store as dense extract.Wash from hydrolysis pretreated wood chip rare extract clear water, and be placed in screw extruder and extrude, the compression ratio of screw extruder is 4:1, collect the filtrate after washing and after again extruding, as rare extract after mixing, be then incorporated to dense extract and be mixed to get extract, store for subsequent use; Collect the wood chip after extruding as the raw material of reducing rules, obtain the wood chip after hot-water pretreatment, for subsequent use, such as deliver to slurrying workshop section;

(4) the extract collected is carried out evaporation and concentration in the temperature range of 45 DEG C, till 30% of former extract concentration, recycling mass concentration be 3.0% diluted acid adjust ph be 2.0 to precipitate lignin (acid-insoluble lignin), then carry out centrifuging treatment.Centrifugal condition is: centrifuge speed 5000 revs/min, centrifugation time 20 minutes, temperature 25 DEG C.After centrifuging treatment, collect supernatant liquor part and sediment fraction respectively.

One, collects supernatant liquor part, joins in supernatant liquor, then carry out centrifuging treatment to precipitate hemicellulose class material by 3 times of ethanol to supernatant liquor volume.Centrifugal condition is: centrifuge speed 5000 revs/min, centrifugation time 20 minutes, temperature 25 DEG C.After centrifuging treatment terminates, collect the ethanol in supernatant liquor, to recycle.The precipitation formed in the process, be by alcohol precipitation obtain based on wood sugar, with the hemicellulose class material of seldom amount arabinose and furfural.Again through washing, abstraction and purification, and at 45 DEG C after drying, the hemicellulose base product of high added value can be had for the production of with exploitation.

They are two years old, by step (4) in sediment fraction mass concentration be 3.0% diluted acid adjust ph to 2.0 and centrifuging treatment (centrifugal condition is: centrifuge speed 5000 revs/min, centrifugation time 20 minutes, temperature 25 DEG C) after, the sediment fraction obtained is acid-insoluble lignin, collects this part lignin for subsequent production and exploitation lignin base product.

The pulping process of the wood chip utilizing the method for above-mentioned hot-water pretreatment to prepare, step is as follows:

(1) the wood chip after hot-water pretreatment is delivered to of the present invention and the slurrying of reducing rules slurrying workshop section.In Chemical impregnation process, add NaOH, metal ion chelation agent and H ₂o ₂, the addition of NaOH is 3.5% of OD wood chip quality, and the addition of metal ion chelation agent (DTPA) is 0.1%, H of OD wood chip quality ₂o ₂addition be 2.0% of OD wood chip quality, treatment temperature is 80 DEG C, in 25 minutes processing times, obtains the wood chip after Chemical impregnation process.

By step (1) in the wood chip through Chemical impregnation process addressed carry out two sections of grinding process: first paragraph is pressure grinding, and actual conditions is: temperature 150 DEG C, pressure 0.3MPa, and mass concentration during grinding is 25%, grinding 3 minutes; Second segment is normal pressure grinding, and actual conditions is: disk mill gap 0.08mm, the mass concentration 15% of slurry.The lumber fibre slurry after grinding is obtained after two sections of grinding process;

By step (2) in lumber fibre slurry be placed in eliminating potential pool and process, condition is: the mass percent 4.0% of slurry, water temperature 90 DEG C, 40 minutes time, by the pulp screen enterprising row filter of the slurry after diving at the wide 0.15mm of seam that disappear, the mass concentration of then dewatering to slurry is about 30%, obtains slurry finished product.

Make handsheet to the slurry finished product that the method for wood chip hot-water pretreatment prepares before utilizing above-mentioned preparative chemistry mechanical pulp, step is as follows:

Taking out a little slurry to manufacture paper with pulp handsheet, is 250mL or degree Schopper-Riegler 45 ゜ SR through the making beating of PFI mill to freedom by above-mentioned slurry, carries out manufacturing paper with pulp of handsheet and corresponding physical property detects according to national standard method.

Testing result:

Key component content in extract: glucose 150kg, wood sugar 340kg, acetic acid 100kg, above content is all based on the OD wood chip content of 1 ton; Hydrolysis wood chip yield 96.9%.

With without from being hydrolyzed compared with pretreated pulping process flow, pressurized refining part of the present invention and beating energy consumption save 13.2% and 13.8% respectively; The physical properties of the sheet pulp of slurry of the present invention is respectively: bulk 2.54cm ³/ g, tensile index 13.5Nm/g, tear index 1.63mNm ²/ g, ISO whiteness 63.3%, opacity 90.6%, light scattering coefficient 42m ²/ kg, absorption coefficient of light 0.6m ²/ kg.

With without from be hydrolyzed compared with pretreated slurry, the bulk of slurry of the present invention reduces by 9.1%, and tensile index increases by 17.8%, tear index reduction by 22.7%, ISO whiteness reduces by 19.1%, opacity improves 5.7%, and light scattering coefficient improves 4.8%, and the absorption coefficient of light improves 133.3%.

Embodiment 2

(2) in the wood chip after screw extrusion process, add water, make the absolute dry mass of wood chip and add the total liquid volume after water than being 1:4(kg:L), the mixture of wood chip and water is placed in boiling vessel or pressure vessel carries out from being hydrolyzed preliminary treatment.In digestion process, the heating-up time controls at 35 minutes, and boiling temperature is 150 DEG C, and temperature retention time is 20 minutes;

(3) the pre-hydrolyzed solution in digester or pressure vessel is extracted out, store as dense extract.Wash from the pretreated wood chip clear water of hydrolysis, and be placed in screw extruder and extrude, the compression ratio of screw extruder is 4:1, collect the filtrate after washing and after again extruding, as rare extract after mixing, be then incorporated to dense extract and be mixed to get extract, store for subsequent use; Wood chip after extruding delivers to slurrying workshop section as the raw material of reducing rules;

(4) the extract collected is carried out evaporation and concentration in the temperature range of 55 DEG C, till 50% of former extract concentration, recycling mass concentration be 3.0% dilute sulfuric acid adjust ph be 2.0 to precipitate lignin (acid-insoluble lignin), then carry out centrifuging treatment.Centrifugal condition is: centrifuge speed 6000 revs/min, centrifugation time 15 minutes, temperature 25 DEG C.After centrifuging treatment, collect supernatant liquor part and sediment fraction respectively.

One, collects supernatant liquor part, joins in supernatant liquor, then carry out centrifuging treatment to precipitate hemicellulose class material by 4 times of ethanol to supernatant liquor volume.Centrifugal condition is: centrifuge speed 6000 revs/min, centrifugation time 15 minutes, temperature 25 DEG C.After centrifuging treatment terminates, collect the ethanol in supernatant liquor, to recycle.The precipitation formed in the process, be by alcohol precipitation obtain based on wood sugar, with the hemicellulose class material of seldom amount arabinose and furfural.Again through washing, abstraction and purification, and at 45 DEG C after drying, the hemicellulose base product of high added value can be had for the production of with exploitation.

They are two years old, by step (4) in sediment fraction mass concentration be 3.0% dilute sulfuric acid adjust ph to 2.0 and centrifuging treatment (centrifugal condition is: centrifuge speed 5000 revs/min, centrifugation time 20 minutes, temperature 25 DEG C) after, the sediment fraction obtained is acid-insoluble lignin.Collect this part lignin for subsequent production and exploitation lignin base product.

(1) the wood chip after hot-water pretreatment is delivered to the slurrying of reducing rules slurrying workshop section.In Chemical impregnation process, add NaOH, metal ion chelation agent and H ₂o ₂, the addition of NaOH is 3.5% of OD wood chip quality, and the addition of metal ion chelation agent (DTPA) is 0.1%, H of OD wood chip quality ₂o ₂addition be 2.0% of OD wood chip quality, treatment temperature is 80 DEG C, in 25 minutes processing times, obtains the wood chip after Chemical impregnation process.

By step (1) in the wood chip through Chemical impregnation process addressed carry out two sections of grinding process: first paragraph is pressure grinding, and actual conditions is: temperature 150 DEG C, pressure 0.3MPa, and mass concentration during grinding is 25%; Second segment is normal pressure grinding, and actual conditions is: disk mill gap 0.08mm, the mass concentration 20% of slurry.The lumber fibre slurry after grinding is obtained after two sections of grinding process;

By step (1) in lumber fibre slurry be placed in eliminating potential pool and process, condition is: the mass percent 4.0% of slurry, water temperature 95 DEG C, 30 minutes time.By the pulp screen enterprising row filter of the slurry after diving at the wide 0.15mm of seam that disappear, the mass concentration of then dewatering to slurry is about 20%, obtains slurry finished product.

Take out a little slurry to manufacture paper with pulp handsheet, by step (7) in the slurry that obtains be 250mL or degree Schopper-Riegler 45 ゜ SR through the making beating of PFI mill to freedom, carry out manufacturing paper with pulp of handsheet according to national standard method and corresponding physical property detects.

Testing result:

Key component content in extract: glucose 280kg, wood sugar 540kg, acetic acid 140kg, above content is all based on the OD wood chip content of 1 ton; Be hydrolyzed wood chip yield 96.8% simultaneously.

With without from being hydrolyzed compared with pretreated pulping process flow, pressurized refining part of the present invention and beating energy consumption save 22.5% and 27.0% respectively; The physical properties of the sheet pulp of slurry of the present invention is respectively: bulk 2.34cm ³/ g, tensile index 17.3Nm/g, tear index 1.58mNm ²/ g, ISO whiteness 45.4%, opacity 96.9%, light scattering coefficient 43m ²/ kg, absorption coefficient of light 2.0m ²/ kg.

With without from be hydrolyzed compared with pretreated slurry, the bulk of slurry of the present invention reduces by 7.9%, and tensile index increases by 28.1%, tear index reduction by 3.1%, ISO whiteness reduces by 28.3%, opacity improves 7.0%, and light scattering coefficient improves 2.4%, and the absorption coefficient of light improves 233.3%.

Embodiment 3

(2) in the wood chip after screw extrusion process, add water, make the absolute dry mass of wood chip and add the total liquid volume after water than being 1:6(kg:L), the mixture of wood chip and water is placed in boiling vessel or pressure vessel carries out from being hydrolyzed preliminary treatment.In digestion process, the heating-up time controls at 30 minutes, and boiling temperature is 140 DEG C, and temperature retention time is 60 minutes;

(3) the pre-hydrolyzed solution in digester or pressure vessel is extracted out, store as dense extract.Wash from the pretreated wood chip clear water of hydrolysis, and be placed in screw extruder and extrude, the compression ratio of screw extruder is 4:1, collect the filtrate after washing and after again extruding, as rare extract after mixing, be then incorporated to dense extract and be mixed to get extract, store for subsequent use; Collect the wood chip after extruding as the raw material of reducing rules, obtain the wood chip after hot-water pretreatment, for subsequent use, such as deliver to slurrying workshop section;

(4) the extract collected is carried out evaporation and concentration in the temperature range of 60 DEG C, till 40% of former extract concentration, recycling mass concentration be 3.0% diluted acid adjust ph be 2.5 to precipitate lignin (acid-insoluble lignin), then carry out centrifuging treatment.Centrifugal condition is: centrifuge speed 6000 revs/min, centrifugation time 15 minutes, temperature 25 DEG C.After centrifuging treatment, collect supernatant liquor part and sediment fraction respectively.

One, collects supernatant liquor part, joins in supernatant liquor, then carry out centrifuging treatment to precipitate hemicellulose class material by 3 times of ethanol to supernatant liquor volume.Centrifugal condition is: centrifuge speed 6000 revs/min, centrifugation time 15 minutes, temperature 25 DEG C.After centrifuging treatment terminates, collect the ethanol in supernatant liquor, to recycle.The precipitation formed in the process, be by alcohol precipitation obtain based on wood sugar, with the hemicellulose class material of seldom amount arabinose and furfural.Again through washing, abstraction and purification, and at 45 DEG C after drying, the hemicellulose base product of high added value can be had for the production of with exploitation.

They are two years old, by step (4) in sediment fraction mass concentration be 3.0% dilute sulfuric acid adjust ph to 2.5 and centrifuging treatment (centrifugal condition is: centrifuge speed 5000 revs/min, centrifugation time 20 minutes, temperature 25 DEG C) after, the sediment fraction obtained is acid-insoluble lignin.Collect this part lignin for subsequent production and exploitation lignin base product.

(1) above-mentioned wood chip after hot-water pretreatment is delivered to of the present invention and the slurrying of reducing rules slurrying workshop section.In Chemical impregnation process, add NaOH, metal ion chelation agent and H ₂o ₂, the addition of NaOH is 3.5% of OD wood chip quality, and the addition of metal ion chelation agent (DTPA) is 0.1%, H of OD wood chip quality ₂o ₂addition be 2.0% of OD wood chip quality, treatment temperature is 80 DEG C, in 25 minutes processing times, obtains the wood chip after Chemical impregnation process.

By step (1) in the wood chip through Chemical impregnation process addressed carry out two sections of grinding process: first paragraph is pressure grinding, and actual conditions is: temperature 150 DEG C, pressure 0.3MPa, and mass concentration during grinding is 25%; Second segment is normal pressure grinding, and actual conditions is: disk mill gap 0.08mm, the mass concentration 15% of slurry.The lumber fibre slurry after grinding is obtained after two sections of grinding process;

By step (2) in lumber fibre slurry be placed in eliminating potential pool and process, condition is: the mass percent 4.0% of slurry, water temperature 90 DEG C, 40 minutes time.By the pulp screen enterprising row filter of the slurry after diving at the wide 0.15mm of seam that disappear, the mass concentration of then dewatering to slurry is about 30%, obtains slurry finished product.

Testing result:

Key component content in pre-hydrolyzed solution: glucose 300kg, wood sugar 580kg, acetic acid 170kg, above content is all based on the OD wood chip content of 1 ton; Be hydrolyzed wood chip yield 96.6% simultaneously.

With without from being hydrolyzed compared with pretreated pulping process flow, pressurized refining part of the present invention and beating energy consumption save 23.1% and 38.7% respectively; The physical properties of the sheet pulp of slurry of the present invention is respectively: bulk 2.38cm ³/ g, tensile index 17.4Nm/g, tear index 1.83mNm ²/ g, ISO whiteness 42.4%, opacity 96.3%, light scattering coefficient 39m ²/ kg, absorption coefficient of light 2.5m ²/ kg.

With without from be hydrolyzed compared with pretreated slurry, the bulk of slurry of the present invention reduces by 6.3%, and tensile index increases by 28.9%, tear index increase by 12.3%, ISO whiteness reduces by 33.0%, opacity improves 6.3%, and light scattering coefficient reduces by 7.1%, and the absorption coefficient of light improves 316.7%.

Embodiment 4

A method to wood chip hot-water pretreatment before preparative chemistry mechanical pulp, step with the step in embodiment 3 (1)-(4).

The pulping process (APMP) of the wood chip utilizing the method for above-mentioned hot-water pretreatment to prepare, step is as follows:

(6) wood chip enters presteaming storehouse and carries out decatize, and presteaming condition is: 90 – 95 DEG C, the time of staying 3 – 10 minutes.Subsequently by first paragraph screw press pre-preg device, the pre-preg time is 1 – 8 minutes.The compression ratio of screw press is 4:1 – 6:1.In Chemical impregnation process, add NaOH, metal ion chelation agent, sodium metasilicate and H ₂o ₂, the addition of NaOH is 1 – 8% of OD wood chip quality, and the addition of metal ion chelation agent is 0.1 – 0.5% of OD wood chip quality, and the addition of sodium metasilicate is 0.5 – 3.0%, H of OD wood chip quality ₂o ₂addition be 1 – 7% of OD wood chip quality; The treatment temperature of this Chemical impregnation is 60 – 90 DEG C, and processing time 10 – 40 minutes, obtains the wood chip after Chemical impregnation process;

(7) the wood chip after first paragraph pre-preg process, carry out second normal pressure and steam storehouse reaction in advance, presteaming condition is: 90 – 95 DEG C, the time of staying 3 – 10 minutes;

(8), by reaction warehouse material out, enter second segment screw press macerator.In Chemical impregnation process, add NaOH, metal ion chelation agent, sodium metasilicate and H ₂o ₂, the addition of NaOH is 1 – 8% of OD wood chip quality, and the addition of metal ion chelation agent is 0.1 – 0.5% of OD wood chip quality, and the addition of sodium metasilicate is 0.5 – 3.0%, H of OD wood chip quality ₂o ₂addition be 1 – 7% of OD wood chip quality; The treatment temperature of this Chemical impregnation is 60 – 90 DEG C, and processing time 10 – 60 minutes, obtains the wood chip after Chemical impregnation process;

(10) send into first paragraph fiberizer subsequently, carry out atmospheric refining runs, after mill after thick slurry dilution, enter second segment fiberizer and carry out atmospheric refining runs again; The refining concentration of first paragraph mill is 15 – 35%, and the refining concentration of second segment mill is 10 – 20%;

By step (10) in lumber fibre slurry be placed in eliminating potential pool and process, condition is: mass percent 3.0 – 4.0% of slurry, water temperature 70 – 95 DEG C, time 20 – 40 minutes, by the pulp screen enterprising row filter of the slurry after diving at the wide 0.15mm of seam that disappear, the mass concentration of then dewatering to slurry is 30%, obtains slurry finished product.

Above-mentioned slurry is prepared into handsheet, and step is as follows:

Testing result:

The physical properties of the sheet pulp of slurry of the present invention is respectively: bulk 2.0-2.8cm ³/ g, tensile index 12-25Nm/g, tear index 1.0-2.0mNm ²/ g, ISO whiteness 40-80%, opacity 70-95%, light scattering coefficient 30-50m ²/ kg, absorption coefficient of light 2.0-4.0m ²/ kg.

Embodiment 5

A method to wood chip hot-water pretreatment before preparative chemistry mechanical pulp, step with the step in embodiment 2 (1)-(4).

The pulping process (P-RCAPMP) of the wood chip utilizing the method for above-mentioned hot-water pretreatment to prepare, step is as follows:

By step (3) described in the wood chip after hot-water pretreatment deliver to the slurrying of reducing rules slurrying workshop section.

(9) the wood chip after second segment pre-preg enters sends into first paragraph fiberizer, and carry out atmospheric refining runs, refining concentration is 15-35%, obtains the wood chip through first paragraph grinding;

By above-mentioned steps (9) in be placed in high density hypo tower through the wood chip of first paragraph grinding and react, reaction condition is: temperature 80 – 95 DEG C, stock quality concentration 20 – 35%, the time of staying 60 – 180 minutes;

(11) send into second segment fiberizer subsequently through the too high dense slurry stopping reaction, carry out atmospheric refining runs, refining concentration is 10 – 20%;

Above-mentioned slurry is prepared into handsheet, and step is as follows:

Testing result:

Claims

1. the method to wood chip hot-water pretreatment before preparative chemistry mechanical pulp, is characterized in that: step is as follows:

1. for supernatant liquor part, doubly join in supernatant liquor to the ethanol of supernatant liquor volume by 2 – 4, then carry out centrifuging treatment to precipitate hemicellulose class material, centrifugal condition is: centrifuge speed 5000 – 8000 revs/min, centrifugation time 10 – 30 minutes, temperature 20 – 30 DEG C; After centrifuging treatment terminates, collect the ethanol in supernatant liquor, to recycle; Collect the precipitation formed in centrifugal process, will precipitate through washing, abstraction and purification, and at 45 – 60 DEG C after drying, the hemicellulose base product produced and develop must be can be used for;

2. the method to wood chip hot-water pretreatment before preparative chemistry mechanical pulp according to claim 1, it is characterized in that: the length and width of described wood chip are of a size of 10 – 30mm, thickness is 3 – 6mm.

3. the method to wood chip hot-water pretreatment before preparative chemistry mechanical pulp according to claim 1, is characterized in that: described step (4) in mass concentration be 3.0% diluted acid be sulfuric acid or hydrochloric acid.

4. the pulping process to the method for wood chip hot-water pretreatment before the preparative chemistry mechanical pulp of utilization as described in any one of claims 1 to 3, is characterized in that: step is as follows:

1. for supernatant liquor part, doubly join in supernatant liquor to the ethanol of supernatant liquor volume by 2 – 4, then carry out centrifuging treatment to precipitate hemicellulose class material, centrifugal condition is: centrifuge speed 5000 – 8000 revs/min, centrifugation time 10 – 30 minutes, temperature 20-30 DEG C; After centrifuging treatment terminates, collect the ethanol in supernatant liquor, to recycle; Collect the precipitation formed in centrifugal process, will precipitate through washing, abstraction and purification, and at 45 – 60 DEG C after drying, the hemicellulose base product produced and develop must be can be used for;

5. the pulping process to the method for wood chip hot-water pretreatment before preparative chemistry mechanical pulp according to claim 4, is characterized in that: described step (5) middle metal ion chelation agent is DTPA or EDTA.

6. the pulping process to the method for wood chip hot-water pretreatment before the preparative chemistry mechanical pulp of utilization as described in any one of claims 1 to 3, is characterized in that: step is as follows:

2. by step (4) in sediment fraction mass concentration be 3.0% diluted acid adjust ph to 2.0 – 2.5, after centrifuging treatment, centrifugal condition is: centrifuge speed 5000 – 8000 revs/min, centrifugation time 10 – 30 minutes, temperature 20-30 DEG C, the sediment fraction obtained is acid-insoluble lignin, collects this part lignin for subsequent production and exploitation lignin base product;

By step (5) described in the wood chip through Chemical impregnation process carry out two sections of grinding process: first paragraph is pressure grinding, actual conditions is: temperature 120 – 170 DEG C, pressure 0.1 – 0.7MPa, grinding 0.5 – 5 minutes, mass concentration during grinding is 10% – 30%; Second segment is normal pressure grinding, and actual conditions is: disk mill gap 0.08 – 0.10mm, and mass concentration 5% – 30% of slurry, obtains the lumber fibre slurry after grinding after two sections of grinding process;

(7) blanching step, in bleaching process, alkali charge be step (7) in the NaOH of slurry oven dry weight 2.0 – 6.0% that obtains, the diethylene triamine pentacetic acid (DTPA) of slurry oven dry weight 0.1 – 0.3% is water-soluble, the ratio kg:L of NaOH and water used, and the ratio kg:L of diethylene triamine pentacetic acid (DTPA) and water used is 1:3, to be then distributed in slurry and full and uniform mixing; Add subsequently step (7) in the hydrogen peroxide of sodium metasilicate and 2.0 – 8.0% of slurry oven dry weight 1.0 – 3.0% and the mixed liquor of the water that need additionally add, wherein, the ratio kg:L of sodium metasilicate and water used, and the ratio kg:L of hydrogen peroxide and water used is 1:3, the mass concentration of slurry in bleach system is made to be 10-35%, rapid stirring slurry makes it mix, and then carries out bleaching action; The actual conditions of bleaching action is: temperature 60 – 90 DEG C, time 100 – 160 minutes, mixing speed 300 – 1000 revs/min; After bleaching action terminates, the slurry with water after bleaching is fully washed, and regulates slurry pH value to be 5.0, disposed slurry finished product must be bleached.

7. the pulping process to the method for wood chip hot-water pretreatment before preparative chemistry mechanical pulp according to claim 6, is characterized in that: described step (5) middle metal ion chelation agent is DTPA or EDTA.

8. the pulping process to the method for wood chip hot-water pretreatment before the preparative chemistry mechanical pulp of utilization as described in any one of claims 1 to 3, is characterized in that: step is as follows:

(6) wood chip enters presteaming storehouse and carries out decatize, and presteaming condition is: 90 – 95 DEG C, the time of staying 3 – 10 minutes; Subsequently by first paragraph screw press pre-preg device, the pre-preg time is 1 – 8 minutes; The compression ratio of screw press is 3:1 – 6:1; In Chemical impregnation process, add NaOH, metal ion chelation agent, sodium metasilicate and H ₂o ₂the addition of NaOH for step (5) described in 1 – 8% of OD wood chip quality of wood chip after hot-water pretreatment, the addition of metal ion chelation agent for step (5) described in 0.1 – 0.5% of OD wood chip quality of wood chip after hot-water pretreatment, the addition of sodium metasilicate for step (5) described in 0.5 – 3.0%, H of OD wood chip quality of wood chip after hot-water pretreatment ₂o ₂addition for step (5) described in 1 – 7% of OD wood chip quality of wood chip after hot-water pretreatment; The treatment temperature of this Chemical impregnation is 60 – 90 DEG C, and processing time 10 – 40 minutes, obtains the wood chip after Chemical impregnation process;

9. the pulping process to the method for wood chip hot-water pretreatment before preparative chemistry mechanical pulp according to claim 8, is characterized in that: described step (6) and (8) in metal ion chelation agent be DTPA or EDTA.

10. the pulping process to the method for wood chip hot-water pretreatment before the preparative chemistry mechanical pulp of utilization as described in any one of claims 1 to 3, is characterized in that: step is as follows:

(6) wood chip enters presteaming storehouse and carries out decatize, and presteaming condition is: 90 – 95 DEG C, the time of staying 3 – 10 minutes; Subsequently by first paragraph screw press pre-preg device, the pre-preg time is 1 – 8 minutes; The compression ratio of screw press is 3:1 – 6:1; In Chemical impregnation process, add NaOH, metal ion chelation agent, sodium metasilicate and H ₂o ₂the addition of NaOH for step (5) described in the 1-8% of OD wood chip quality of wood chip after hot-water pretreatment, the addition of metal ion chelation agent is 0.1 – 0.5% of OD wood chip quality, and the addition of sodium metasilicate is 0.5 – 3.0%, H of OD wood chip quality ₂o ₂addition be 1 – 7% of OD wood chip quality; The treatment temperature of this Chemical impregnation is 60 – 90 DEG C, and processing time 10 – 40 minutes, obtains the wood chip after Chemical impregnation process;