CN1143398A - Influence of Temperature and Alkali Material on Pulp Brightness - Google Patents

Abstract

A method for improving pulp brightness utilizes a combination of a distributed total white liquor charge during the warm fill, hot fill and cooking stages of a batch cooking process and low cooking temperatures during the cooking stage. The high total white liquor charge ranges between 15 % AA &tilde& 35 % AA, while the cooking temperatures range between 150 and 168 DEG C.

Description

Temperature and alkali material are to the influence of pulp brightness

The present invention relates to a kind of method that improves the final whiteness of paper pulp.More specifically, the present invention relates to replace fast in the hot digestion system to boiling temperature and the improvement of liquid charging in vain.

Displacement heating (" RDH ") is a low-yield batch cooking method of making kraft pulp fast.The intrinsic advantages of the energy efficiency of continuous digester and batch cooking is got up, and the mid-waste black liquor of changing of digester that RDH reuses boiling comes the wood chip in the follow-up boiling of preliminary treatment.Therefore, chemicals in these waste liquids and heat are circulated to follow-up boiling.In the follow-up boiling to the preliminary treatment of fresh wood chip from low temperature liquid (about 80 ℃-130 ℃), then be high temperature liquid (about 130 ℃-165 ℃), this high temperature liquid be with steam be warming up to final boiling temperature (170 ℃) before digester to possible maximum temperature.

RDH and other alkaline boiling method generate the relative black paper pulp of color.In many purposes of paper pulp and paper, usually need bigger contrast, so become high whiteness manufacturing to be used to write white paper pulp with printing paper and cardboard usually to association with pulp bleaching.The color of paper pulp is that the variation owing to lignin component in the raw material in the pulping process causes.Regrettably, in the RDH method, use high boiling temperature and low black liquor intensity, make and use conventional, no chlorine element (ECF) and low bleaching property problem occurred completely without chlorine (TCF) bleaching.As if high temperature and low black liquor have quickened condensation reaction, have caused the condensation of lignin and lignin and other timber extracts.As a result, reduced the bleaching property of paper pulp.

Therefore, in the RDH cooking process, need another method to eliminate these disadvantageous side reactions and improve the bleaching property of paper pulp.

The invention provides a kind of method that improves pulp brightness.Based on to using the improvement of quick displacement heating batch cooking method, the step that method of the present invention is and initial hot feed reinforced to temperature are added white liquor (% active alkalinity (AA) or effective alkalinity (EA)) or NaOH in the stage a step with under than the low temperature of previously used intermittent operation boiling wood chip prepares the paper pulp that bleaching property improved combines.In this respect, total white liquid material of 15%AA-35%AA is assigned to warm, heat with predetermined amount and in the boiling stage.If use cooling buffer (cool pad) in the embodiment of this invention, cold white liquid also joins in the black liquor that gives off from cold liquid holding vessel.Basically, white liquid joined before actual boiling in each stage of batch cooking process.

In the digestion process of wood chip, there are white liquid and black liquor in the digester.Boiling temperature is low, is 150 ℃-167 ℃.High AA or the white liquid material of EA and low boiling temperature are combined, improved the final whiteness of paper pulp.As a result, in the operation of slurry factory, reduced the use of pollutant and bleaching chemical.

Fig. 1 represents the schematic diagram of digester and its associated devices in this RDH decoction system.

Fig. 2 A, 2B and 2C are illustrated in the distribution or the adding of white liquid in each step of RDH digestion process.In Fig. 2 A, the initial stage that curve A is illustrated in warm feed way adds a spot of white liquid.The white liquid that curve B is represented the boiling step and represented to exist in the digester in the actual digestion process of wood chip.

Fig. 2 B is illustrated in each step of RDH digestion process and adds continuously white liquid to black liquor, from the reinforced beginning of temperature and last till that hot feed finishes.As shown in the figure, in actual digestion process, also there is white liquid in the digester.

Fig. 2 C is illustrated in and adds white liquid in each step of RDH continuously, comprises always adding white liquid in the wash engine filtrate of displacement tank.

Fig. 3 is illustrated in the step 3 RDH system that does not have white liquid to add in the reinforced and hot feed mode process of temperature.

The step 3RDH system that Fig. 4 has white liquid to add in temperature in the reinforced and hot feed type method.

Fig. 5 represents the preferred example of RDH paper pulp and the D1-whiteness and the reinforced relation curve of total (D100+D1) effective chlorine of baseline example.Curve A is represented RDH paper pulp R3 (the 0.225 card uncle factor).Curve B is represented RDH paper pulp R4 (the 0.27 card uncle factor).Curve C is represented RDH paper pulp R7 (the 0.225 fastener factor).Curve D is represented RDH paper pulp R8 (the 0.27 card uncle factor).

Fig. 5 A represents D1-whiteness and the reinforced relation curve of D1-chlorine dioxide.Curve A is represented RDH paper pulp R3 (the 0.225 card uncle factor).Curve B is represented RDH paper pulp R4 (the 0.27 card uncle factor).Curve C is represented RDH paper pulp R7 (the 0.225 card uncle factor).Curve D is represented RDH paper pulp R8 (the 0.27 card uncle factor).

Fig. 6 represents D1-whiteness and the reinforced relation of total available chlorine in the D100-of all 0.225 card uncle factor bleachings and the D1-step.Curve A is represented RDH paper pulp R3.Curve B is represented RDH paper pulp R12.Curve C is represented RDH paper pulp R7.

Fig. 6 A represents D1-whiteness and the reinforced relation of D1-step 2 chlorine monoxid.Curve A is represented RDH paper pulp R3 (the 0.225 card uncle factor).Curve C is represented RDH paper pulp R7 (the 0.225 card uncle factor).

Fig. 7 represents D1-whiteness and the reinforced relation of total available chlorine in the D100-of 0.27 all card uncle factor bleachings and the D1-step.Curve A is represented RDH paper pulp R4.Curve B is represented RDH paper pulp R12.Curve C is represented RDH paper pulp R8.

Fig. 7 A represents D1-whiteness and the reinforced relation of D1-step 2 chlorine monoxid.Curve A is represented RDH paper pulp R4 (the 0.27 card uncle factor).Curve B is represented RDH paper pulp R12 (the 0.27 card uncle factor).Curve C is represented RDH paper pulp R8 (the 0.27 card uncle factor).

The invention provides a kind of method that improves paper pulp bleaching property, the method is based on the improvement of the existing RDH decoction system of boiling wood chip. More specifically, the initial period that this method relates in RDH boiling circulation begins to add white liquid material, and lasts till the temperature rise period of this process, at this moment begins actual boiling. Method of the present invention also is based on to use and compares slightly low boiling temperature with the boiling temperature of normally used RDH cooking process and carry out actual boiling.

According to the present invention, the total white liquid material of about 15%AA-35%AA is distributed in warm black liquor, initial hot black liquor and boiling stage. When cooling buffer or the use of cold liquid reservoir, also receive white liquid material. Except the white liquid material with distribution, the present invention also uses about 150-167 ℃ low boiling temperature. As a result, with the bleaching of the bleaching chemical of any combination, prepared the paper pulp that final whiteness has been improved.

The operational phase of concrete RDH digestion system is as follows: (1) adds wood chip; (2) add cold black liquid; (3) add warm black liquor; (4) add hot black liquor; (5) temperature rise period (time to temperature); (6) holding stage (time at temperature); (7) displacement; (8) extract out with pump.U.S. Patent No. 4,578, the basic principle of RDH operation has been introduced in 149 (promulgations in March 25 in 1986), and the whole contents of this patent is introduced this specification as a reference.Correspondingly, the discussion of RDH details of operation only can be understood on the improved basis of RDH decoction system at this field those of ordinary skill and carries out, and this operation has prepared the paper pulp of bleached level described here.

Fig. 1 shows the device type of the RDH device that is used for cooking of pulp.Should understand, the figure shows the most general character of digesting apparatus, in fact this system done to improve and change, this will go through below.For the reason of simplifying, many devices in disclosed figure, have been saved, for example measuring instrument, forced draught hole, pump and valve.Fig. 1 is used for representing that existing RDH cooking process is also with helping understand based on the improvement of the principle of the invention to this method.

With reference to figure 1, this digester that is generally used for the wood chip chemical steaming is represented with 10.Digester 10 has the bottom surface 12 of a bevel.The various reactant liquors of inlet valve 14 controls enter digester 10.Though do not illustrate, pump into cooking liquor by heat exchanger or the steam-jet sprayer that is connected on the digester 10 by valve control pipeline, can be heated to the inclusions in the digester 10 final boiling temperature.

After wood chip adds digester 10,, from cold liquid holding vessel (A jar) 16 cold black liquid (the about 70-95 of temperature ℃) is pumped into the bottom of digester 10 by inlet valve 14 via the pipeline 20 of valve 22 controls by pump 18.Then, from warm liquid holding vessel 24 warm liquid (the about 90-150 of temperature ℃) is pumped and sends into through valve 14 bottom of digester 10 through valve 22 by pump 18.In the reinforced process of warm liquid, some black liquor displace from digester 10, turn back in the cold liquid holding vessel 16 by pipeline 26 then.From hydrothermal solution holding vessel (C jar) hot black liquor (temperature is 150-168 ℃) is pumped into the bottom of digester 10 then through valve 14 via the pump 30 of valve 32 controls.In the reinforced process of hydrothermal solution, black liquor displaces from digester 10 and turns back to warm liquid holding vessel 24 and hydrothermal solution holding vessel 28 by pipeline 34 and 36 respectively.In hydrothermal solution reinforced mid-term, the white liquid of heat that is stored in the white liquid holding vessel 38 of heat pumps through pump 30, and mixes with hot black liquor from the outflow of hydrothermal solution holding vessel 28 at pump 30 places, and this mixed liquor enters digester 10 bottoms by valve 32 then.

After hot feed was finished, when the temperature rise period began, the import and the outlet valve of digester 10 were closed.Steam sprays into digester 10 and temperature is raised to boiling temperature, average about 170 ℃.According to the white liquid material and the H-factor, the temperature maintenance of digester is finished up to the boiling wood chip in about this temperature.

After finishing the boiling stage, the wash engine filtrate (the about 70-85 of temperature ℃) of leaving displacement tank (D jar) 40 in is pumped into digester 10 with pump 42 and valve 44.The inclusions of washing digester 10 is also cooled off digester 10.When digester 10 adds wash engine filtrate, waste liquid is replaced and is turned back in warm liquid holding vessel 24 and the hydrothermal solution holding vessel 28 by pipeline 46 and 48 respectively.When having used all wash engine filtrate (the washing factor by wash engine is decided), replacement process is through with.After finishing displacement, then the paper pulp of boiling is pumped from digester 10, send in the discharge tank with pump 50.

For existing RDH decoction system, for using, high speed cooking is higher than 170 ℃ boiling temperature, cause the acceleration of condensation reaction.As a result, when paper pulp through routine, when ECF and TCF bleaching, the problem of bleaching property has appearred.The present invention is by improving the bleaching property that the chip steaming method has overcome these problems and improved paper pulp.This improved RDH cooking process combines higher basicity (or white liquid charging) and lower boiling temperature.More specifically, add white liquid at warm liquid and reinforced stage of initial hydrothermal solution.This is opposite with existing RDH cooking process, and white liquid only adds in the mid-term of hydrothermal solution feed way in existing RDH cooking process.In addition, when using the cooling buffer in the present invention, white liquid joins in the cold black liquid that flows out from cold liquid holding vessel (or A jar).Therefore, up to the temperature rise period, white liquid all adds black liquor in each stage from the beginning of RDH cooking process.The distribution of white liquid is also named in the adding of each white liquid of stage, and below Fig. 2 A, 2B and 2C illustrate in greater detail.

Among Fig. 2 A, curve A represents that when warm black liquor leaves B jar or warm liquid holding vessel and flows to digester a small amount of white liquid added when warm feed way began.Also can in A jar or cooling buffer (during use), add white liquid.In the latter stage of using two hydrothermal solution storages to recommend the hot feed mode of device C1 and C2, the mixture of white liquid and black liquor is still stayed digester.Curve B is represented the boiling stage, and is illustrated in the actual digestion process of wood chip has white liquid in digester.In digestion process, also there is black liquor.

Fig. 2 B represents to add white liquid continuously from each stage of the warm reinforced digestion process that finishes up to the hot feed mode in black liquor.

Fig. 2 C represents the white liquid of continuous adding of each stage, comprises adding white liquid to the wash engine filtrate of flowing out from displacement tank.

Compared in warm and hot feed operating process, to have and do not have white liquid to add fashionable initial hot feed and operated the organic concentration of dissolving in (C1 and C2 jar contain black liquor).Fig. 3 is illustrated in the step 3 RDH system that does not have white liquid to add in warm and the hot feed mode process.In warm feed way, have only warm black liquor to leave warm liquid holding vessel (B jar) 24 and flow and inflow line 20, flow into digester 10 then by pipeline 56.Though this RDH system comprises two hydrothermal solution holding vessels 28 (C1 jar) and 58 (C2 jars) respectively, and the RDH pulp-making method of only using a hydrothermal solution holding vessel is arranged.In enforcement of the present invention, considered that this white liquid apportion design can be used for containing the system of any number black liquor holding vessel.

As shown in Figure 3, in initial hot feed mode process, hot black liquor flows out from hydrothermal solution holding vessel 28,58 by pipeline 60,62 respectively, and flows into digester 10 by pipeline 64 and 20.In hot feed mid-term, the white liquid of heat that comes out from the white liquid holding vessel 38 of heat with mix from the hot black liquor of hot black liquor holding vessel 58 by pipeline 66 outflows.Then, this mixture flows by pipeline 64 and 20, and flows in the digester 10.

Fig. 4 is illustrated in the step 3 RDH system that has white liquid to add in warm and the hot feed mode process.At first, in warm reinforced process, to the warm black liquor that flows out by pipeline 70 from warm liquid holding vessel 24, add white liquid.This is warm reinforced by pipeline 56 and 20 inflow digesters 10.In warm feed way process, can use white liquid cold or heat.In initial hot feed mode process, the white liquid of heat that comes out from the white liquid holding vessel 38 of heat with mix from the black liquor of hydrothermal solution holding vessel 28 by pipeline 72 outflows, and further mix with black liquor from second hydrothermal solution holding vessel 58 by pipeline 62,66 outflows.The white liquid of this heat and black liquor mixture flow into the digester 10 by pipeline 64 and 20 from two hydrothermal solution holding vessels 28 and 58.

The result is compared as follows:

In warm and hot feed operation, there is not white liquid to add (Fig. 3)

The organic matter % of initial hot feed operation total flow gallon/digester time dissolving

C1 black liquor 20,799 13.1

C2 black liquor 8,709 14.9

In warm and hot feed operation, there is white liquid to add (Fig. 4)

White liquid material: the 1.5%AA of C1 black liquor

The 1.5%AA of C2 black liquor

The organic matter % of initial hot feed operation total flow gallon/digester time dissolving

C1 black liquor 19,877 10.1

C2 black liquor 7,971 9.8

The research of this situation has clearly illustrated by the thermotropism charge line and has added the concentration that white liquid can be regulated the organic compound of dissolving in the initial hot feed operation.The organic concentration of dissolving in C1 black liquor and C2 black liquor is respectively from 13.1% dropping to 10.1%, dropping to 9.8% from 14.9%.

In order to make RDH method maximization bleaching property and to enlarge delignification, warm black liquor (the about 70-150 of temperature ℃, intensity is 3-20g/lAA) and hot black liquor (the about 100-168 of temperature ℃, intensity be 8-30g/lAA) should be by being strengthened with any combination of white liquid or NaOH solution.

Illustrate shown in the figure as top, warm and hot black liquor can improve by the distribution of white liquid.These black liquor also can obtain modification by distributing NaOH.By using any combination of black liquor, white liquid and NaOH, the adding of white liquid or NaOH has been controlled consolidating of total dissolving and has been contained the concentration of thing (TDS) and the intensity of black liquor.The wash engine filtrate displacement stage, can be strengthened by any combination with white liquid or NaOH solution, the temperature of black liquor is maintained at about 50-105 ℃, the intensity of black liquor between 1-18g/lAA in this filtrate displacement stage.

By embodiment, but be not limited to this, the following examples further specify the present invention as embodiment preferred.

As follows, table 1,1A, 2,2A, 3 and 3A provided the slurrying result and the condition of some digesters time of the RDH paper pulp that is used to be prepared as following bleaching research.Table 3B has summarized the slurrying result.

Annotate: AA: active alkalinity

The TAPPI:(U.S.) pulp and paper technology association

EA: effective alkalinity

ISO: standardization international organization

CED: cupri ethylene diamine

TTA: total titration alkali

Table 1RDH slurrying condition and result-" preferred example "

Digester	????R1	Back R1	????R2	Back R2	????R3	Back R3	????R4	Back R4
									The H factor	????937		????532		????475		????452
The AA of hot feed (TAPPI) %	???16.0		???16.0		???16.0		?????16
									Based on the sulphidity (TAPPI) of AA, %	???30.4		?????30		???30.3		????30. ??????2
Maximum temperature, C	????160		????160		????160		????160
									To the time of maximum temperature, divide	?????16		?????20		?????17		?????19
In the time of maximum temperature, divide	????130		?????37		?????60		?????57

Card the primary, not screening	????7.2		????8.9		?????9.2		????9.8
									Card the primary sieved	????7.1		????8.2		?????8.8	°	????9.3
Gross production rate, %	???46.3		???47.3		????48.2		????1.7
									Total waste material, %	????0.9		????1.2		?????1.4		????1.7
Productive rate after the screening, %	???45.4		???46.1		????46.8		????46. ??????9
									Viscosity, 0.5% CED, centipoise	?????26		?????39		????40.7		????44. ??????9
									Boiling residue during end:
AA(Na 2O)， g/L	????28.2		????31.6		????32.9		????31. ??????6
									EA(Na 2O)， g/L	????21.1		????24.2		????24.2		????24. ??????2
Na 2S(Na 2O)， g/L	????14.3		????14.9		????17.4		????14. ??????9
									TTA(Na 2O)，g/L
Admittedly contain thing, %	????14.8		????15.9		????16.7		????16. ??????8
									Admittedly contain thing, g/L	?????161		?????173		?????183		????185
Based on the sulphidity of AA, %	??????51		????47.1		????52.9		????47. ??????1
									Hot feed:
The hydrothermal solution charging, L	??????18		??????18		??????18		????18
									Feed time is divided	??????13		??????14		??????13		????13
Temperature, C
									The top	?????130		?????127		?????127		???128
The bottom	?????145		?????141		?????141		???141

Electrochemical conditions in the holding vessel:
									AA(Na 2O)， g/L	????22.9	????20.6	????25.7	????21.7	????29.2	????24.6	????27. ??????3	????23.6
EA(Na 2O)， g/L	????16.1	????15.1	????18.1	????16.1	????20.2	????18.3	????19. ??????8	????17.9
									Na 2S(Na 2O)， g/L	????13.7	??????11	????15.2	????11.2	??????18	????12.7	????14. ??????9	????11.4
TTA(Na 2O)， g/L	???????-	???????-	???????-	???????-	???????-	???????-	??????-	???????-
									Based on the sulphidity of AA, %	????59.4	????53.4	????59.1	????51.6	????61.6	????51.2	????54. ??????9	????48.3
Admittedly contain thing, %	?????9.5	????10.5	????11.1	????11.9	????11.9	????13.6	????12. ??????7	????13.6
									Admittedly contain thing, g/L	????99.8	?????111	?????118	?????127	?????127	?????146	????137	?????146
The wastage in bulk or weight time, divide *	??????45		??????43		??????41		?????42

^*Comprise that the time and the injection of initial hot black liquor that are heated to 145 ℃ mix the time of back in the time of 145 ℃ with final hot black liquor and white liquid.

Table 1ARDH slurrying condition and result-" preferred example "

Digester	????R1	Back R1	????R2	Back R2	????R3	Back R3	????R4	Back R4
									White liquid:
White liquid material, L	????6.04		????5.65		????5.53		????5.52
									The white liquid of heat, L	???????5		????4.13		?????5.5		?????5.8
Feed time is divided	??????11		??????11		???????9		???????9
									Temperature C
The top	?????140		?????139		?????140		?????139
									The bottom	?????141		?????141		?????144		?????143

Electrochemical conditions in the holding vessel: (TAPPI)
									AA(Na 2O)， g/L	??????98		????99.2		?????10. ???????2	??°	????101. ???????5
EA(Na 2O) g/L	????83.1		????84.3		????85.8		????86.2
									Na 2S(Na 2O)， g/L	???????-		???????-		???????-		???????-
TTA (Na 2O)， g/L
									Based on the sulphidity of AA, %	????30.4		??????30		????30.3		????30.2
Wood chip charging ﹠ liquid is filled
									The wood chip material, g	???3,700		???3,500		????3,50 ???????0		????3,50 ???????0
Wood chip humidity, %	????37.3		????37.3		????37.3		????37.3
									Over dry contains thing % admittedly	????62.7		????62.7		????62.7		????62.7
Warm reinforced:
									The warm liquid charging, L	????24.7		??????24		??????24		??????24
Outlet pH, initial	????12.8		????13.5		????13.3		????13.3
									Feed time is divided	??????15		??????15		??????15		??????15
Temperature, C
									The top	?????100		?????104		?????102		?????100
The bottom	?????113		?????112		?????111		?????112
									Electrochemical conditions in the holding vessel:
AA(Na 2O)， g/L	????23.6	????16.4	????26.4	????17.7	????25.7	????19.2	????28.5	????21.1
									EA(Na 2O)， g/L	????16.4	????10.5	????17.4	????11.5	??????18	????12.4	????18.6	????13.6
Na 2S (Na 2O)， g/L	????14.3	????11.8	??????18	????12.4	????15.5	????13.6	????19.8	????14.9
									TTA (Na 2O)， g/L	???????-	???????-	???????-	???????-	???????-	???????-	???????-	???????-
Based on the sulphidity of AA, %	????60.8	????71.7	????68.3	????70.2	????60.3	??????71	????69.5	????70.6

Admittedly contain thing, %	???????9	????9.25	????13.6	????12.4	????14.3	????13.1	????14.1	????13.1
									Admittedly contain thing g/L	????94.3	????96.4	?????147	?????131	?????155	?????141 ????°	?????152	?????141
The wastage in bulk or weight time, divide *	??????40		??????31		??????34		??????33
									Displacement
Displaced volume, L	??????32		??????32		??????32		??????32
									Feed time is divided	??????26		??????25		??????26		??????26
Electrochemical conditions in the holding vessel: (TAPPI)
									AA(Na 2O)， g/L	?????9.5		????10.1		???????9		????10.1
EA(Na 2O)， g/L	?????9.5		????10.1		???????9		????10.1
									Na 2S (Na 2O) g/L	???????-		???????-		???????-		???????-
TTA (Na 2O)， g/L	???????-		???????-		???????-		???????-
									Based on the sulphidity of AA, %	???????0		???????0		???????0		???????0

^*Comprise that the heat time heating time of reinforced time to 120 ℃ and warm reinforced back are time of 120 ℃

Table 2 RDH slurrying condition and result-" baseline example "

Digester	????R5	Back R5	????R6	Back R6	????R7	Back R7	????R8	Back R8
									The H factor	???116 ?????1		???765		???831		???832
The AA of hot feed (TAPPI), %	???10. ?????0		??10.0		??10.0		??10.0
									Based on the sulphidity (TAPPI) of AA, %	???30. ?????2		??30.3		??30.3		??30.2

Maximum temperature, C	???170		???170		???170		???170
									To the time of maximum temperature, divide	????23		????27		????21	?°	????21
In the time that maximum temperature keeps, divide	????62		????35		????41		????42
									Card the primary was unscreened	???7.6		???9.7		???9.5		???8.9
Card the primary sieved	???7.2		???9.1		???8.9		???8.8
									Gross production rate, %	???47. ?????3		??48.3		??48.6		??49.1
Total waste material %	???1.1		???1.6		???1.7		???1.4
									Productive rate % after the screening	???46. ?????2		??46.7		??46.9		??47.7
Viscosity, 0.5% CED, centipoise	???19. ?????5		??33.2		??33.3		??32.2
Last boiling residue:
									AA(Na 2O) g/L	???27. ?????9		??25.4		????26		??25.4
EA (Na 2O)， g/L	???19. ?????2		????18		??17.4		??17.4
									Na 2S (Na 2O)， g/L	???17. ?????4		??14.9		??17.4		????16
TTA(Na 2O) g/L
									Admittedly contain thing, %	????19		??19.1		??19.2		??19.1
Admittedly contain thing, g/L	???210		???211		???213		???210
									Based on the sulphidity of AA, %	???62. ?????4		??58.3		??66.2		????63

Hot feed:
									The hydrothermal solution charging, L	????18		????18		????18	??°	????18
Feed time is divided	????12		????13		????12		????13
									Temperature, C
The top	???135		???137		???137		???135
									The bottom	???153		???153		???154		???155
Electrochemical conditions in the holding vessel:
									AA(Na 2O) ，g/L	???30. ?????4	???23.6	????26	???21.1	??26.7	??20.5	??26.4	??20.5
EA (Na 2O)， g/L	???22. ?????3	???16.2	??18.6	???14.3	????18	??13.6	??18.3	??13.6
									Na 2S (Na 2O)， g/L	???16. ?????1	???14.9	??14.9	???13.6	??17.4	??13.6	??16.1	??13.6
TTA (Na 2O)， g/L	?????-	??????-	?????-	??????-	?????-	?????-	?????-	?????-
									Based on the sulphidity of AA, %	???53. ?????3	???63.6	??56.9	???64.5	??65.2	??67.3	??61.4	??67.3
Admittedly contain thing, %	???16. ?????7	?????17	??17.2	???17.1	????17	??17.3	????17	??16.9
									Admittedly contain thing, g/L	???183	????185	???189	????187	???187	???189	???186	???184
The wastage in bulk or weight time, divide *	????46		????44		????45		????44

^*Comprise that the time that is heated to 155 ℃ and initial hot black liquor spray and final hot black liquor and white liquid mix the back time of 155 ℃.

Table 2ARDH slurrying condition and result-" baseline row "

Digester	????R5	Back R5	????R6	Back R6	????R7	Back R7	????R8	Back R8
									White liquid:
White liquid material, L	????3.47		????3.45		????3.46		????3.47
									The white liquid of heat .L	?????5.4		???????7		?????5.6		???????5
Feed time is divided	???????9		???????9		???????9		???????9
									Temperature, C
The top	?????151		?????152		?????151		?????151
									The bottom	?????149		?????147		?????145		?????144
Electrochemical conditions in the holding vessel: (TAPPI)
									AA (Na 2O)， g/L	???100.8		???101.4		???101.2		????100. ???????8
EA(Na 2O) g/L	????85.6		??????86		????85.9		????85.6
									?Na 2S (Na 2O) g/L	???????-		???????-		???????-		???????-
TTA (Na 2O)， g/L	???121.6		???122.8		???123.1		????120. ???????6
									Based on the sulphidity of AA, %	????30.2		????30.3		????30.3		????30.2
Wood chip charging ﹠ liquid is filled
									The wood chip material, g	???3,500		???3,500		???3,500		????3,50 ???????0
Wood chip humidity, %	????37.3		????37.3		????37.3		????37.3
									Over dry contains thing % admittedly	????62.7		????62.7		????62.7		????62.7

Warm reinforced
									The warm liquid material, L	????24.4		??????25		???25.2	??°	??????24
Outlet pH, initial	????13.1		????13.3		???13.5		????13.3
									Feed time is divided	??????15		??????15		?????15		??????15
Temperature, C
									The top	?????109		?????109		????106		?????106
The bottom	?????121		?????120		????118		?????116
									Electrochemical conditions in the holding vessel (TAPPI)
AA(Na 2O) ，g/L	????28.1	?????19.2	????27.9	????18.6	???26.7	????19.2	????26.7	????19.7
									EA (Na 2O)， g/L	????18.3	?????12.4	??????18	????11.2	?????18	????11.8	????18.6	????12.1
Na 2S (Na 2O)， g/L	????19.6	?????13.6	????19.8	????14.9	???17.4	????14.9	????16.1	????15.1
									Based on the sulphidity of AA, %	????69.8	?????70.8	??????71	????79.6	???65.2	????77.1	????60.7	????77.2
Admittedly contain thing, %	????14.5	?????15.4	??????15	??????16	???14.7	????15.5	????14.6	????15.9
									Admittedly contain thing, g/L	?????157	??????167	?????164	?????173	????159	????168	?????158	?????172
The wastage in bulk or weight time, divide *	??????35		??????33		?????31		??????30
									Displacement
Displaced volume, L	??????32		??????32		?????32		??????32
									Feed time is divided	??????26		??????26		?????26		??????26
Electrochemical conditions in the holding vessel:
									AA (Na 2O)， g/L	?????4.3		????4.31		????4.3		?????4.3
EA (Na 2O)， g/L	?????3.7		?????3.7		????3.7		?????3.5

Na 2S (Na 2O)， g/L	????1.24		????1.24		????1.24	???°	????1.74
									Based on the sulphidity of AA, %	????27.9		????27.9		????27.9		????27.9
Admittedly contain thing, %	?????9.7		????10.6		????10.4		????10.3
									Admittedly contain thing, g/L	?????102		?????112		?????109		?????108

^*Comprise feed time, be heated to 120 ℃ time and warmly maintain 120 ℃ time after reinforced.

Table 3RDH slurrying condition and result-" practicable preferred example "

Digester	?????R9	Back R9	????R10	Back R10	????R11	Back R11	????R12	Back R12
									The H factor	????484		????558		????483		????494
The AA of hot feed (TAPPI), %	???18.9		???16.0		???16.0		?????16
									Based on the sulphidity of AA, %	???30.6		???30.2		???29.8		???30.4
Maximum temperature, C	????160		????160		????160		????160
									To the time of maximum temperature, divide	?????20		?????20		?????18		?????16
In the time of maximum temperature, divide	?????60		?????72		?????62		?????63
									Card the primary, not screening	????9.1		????8.9		????9.6		?????10
Card the primary screened	????8.1		????8.5		????9.2		????9.3
									Gross production rate, %	???48.1		???48.1		???49.1		???49.1
Total waste material, %	????1.1		????1.2		????1.5		????1.3
									Productive rate % after the screening	?????47		???46.9		???47.6		???47.8
Viscosity, 0.5% CED, centipoise	???33.5		?????33		???39.3		???32.1

Last boiling residue
									AA(Na 2O)， g/L	????37.6		????32.8		??34.1	?°	????33.5
EA(Na 2O)， g/L	????28.6		????25.3		??25.9		????25.3
									?Na 2S (Na 2O)，g/L	????17.9		????15.2		??16.4		????16.4
Admittedly contain thing, %	????18.8		????19.1		??19.2		????19.3
									Gu compound, g/L	?????210		?????212		???215		?????214
Based on the sulphidity of AA, %	????47.9		????45.7		??48.1		??????49
									Hot feed:
The hydrothermal solution charging, L	??????18		??????18		????18		????18.7
									Feed time is divided	??????13		??????13		????13		??????13
Temperature, C
									The top	?????129		?????132		???132		?????132
The bottom	?????145		?????147		???147		?????145
									Electrochemical conditions in the holding vessel:
AA(Na 2O)， g/L	????27.8	????25.9	????27.3	????25.3	??27.1	??24.6	????26.5	??23.4
									EA(Na 2O)， 9/L	????19.9	????18.9	????19.9	????18.3	??20.2	??18.3	????19.5 ???????7	????17
Na 2S (Na 2O)，g/L	????15.8	????13.4	????14.9	????13.9	??13.9	??12.6	????13.9	??12.6
									TTA(Na 2O)， g/L	???????-	???????-	???????-	???????-	?????-	?????-	???????-	?????-
Based on AA, sulphidity, %	????56.8	????54.1	????54.2	????55.3	??50.9	??51.2	????52.3	??54.7
									Admittedly contain thing, %	????16.2	????16.1	????16.7	????16.7	????17	??17.2	????17.3	????17
Admittedly contain thing, g/L	?????177	?????176	?????182	?????183	???187	???189	?????190	???186
									The wastage in bulk or weight time, divide *	??????42		??????42		????42		??????39

^*Comprise: be heated to 145 ℃ time, initial hot black liquor sprays with final hot black liquor with after liquid mixes in vain and maintains 145 ℃ time.

Table 3ARDH slurrying condition and result-" practicable preferred example "

Digester	????R9	Back R9	????R10	Back R10	????R11	Back R11	????R12	Back R12
									White liquid:
White liquid material, L	????6.17		????5.81		????5.79		????5.6
									The white liquid of heat, L	?????4.8		?????5.2		?????5.0		????6.4
Feed time is divided	??????10		??????10		??????10		??????9
									Temperature, C
The top	?????139		?????140		?????139		????141
									The bottom	?????139		?????145		?????140		????144
Electrochemical conditions in the holding vessel: (TAPPI)
									AA (Na 2O)， g/L	???107.3		????96.4		????96.7		????100
EA(Na 2O) g/L	????90.8		????81.8		????82.3		???84.8
									TTA (Na 2O)， g/L	???125.8		???115.6		???117.8		???120. ??????9
Based on the sulphidity of AA, %	????30.6		????30.2		????29.8		???30.4
									Wood chip charging ﹠ liquid is filled
The wood chip material, g	???3,500		???3,500		???3,500		???3,50 ??????0
									Wood chip humidity, %	????37.3		????37.3		????37.3		????37.3
Over dry contains thing % admittedly	????62.7		????62.7		????62.7		????62.7

Warm reinforced:
									Warm liquid charging, L	????24.5		????24.3		????23.9	??°	????24.2
The pH of outlet, initial	????13.3		????13.2		????13.2		??????13
									Feed time is divided	??????15		??????15		??????15		??????15
Temperature, C
									The top	?????108		?????106		?????104		?????108
The bottom	?????121		?????117		?????116		?????118
									Electrochemical conditions in the holding vessel: (TAPPI)
AA(Na 2O) ，g/L	????27.1	????21.1	????26.5	????21.1	????26.5	????20.8	????25.9	????20.8
									EA (Na 2O)， g/L	????20.5	????14.5	????18.9	????14.1	????18.3	????13.3	????17.7	????13.3
Na 2S (Na 2O)， g/L	????13.3	????13.3	????15.2	????14.1	????16.4	????15.2	????16.4	????15.2
									Based on the sulphidity of AA, %	????48.7	????62.6	????57.4	????66.4	????61.9	????72.1	????63.3	????72.1
Admittedly contain thing, %	????14.3	????14.9	????14.8	????15.8	????15.6	????16.1	??????15	????15.6
									Admittedly contain thing, g/L	?????155	?????161	?????162	?????171	?????170	?????176	?????163	?????170
The wastage in bulk or weight time, divide *	??????30		??????30		??????31		??????30
									Displacement
Displaced volume, L	??????32		??????32		??????32		??????32
									Feed time is divided	??????26		??????26		??????26		??????26

Electrochemical conditions in the holding vessel: (TAPPI)
									AA (Na 2O)， g/L	????9.5		????9.8		????8.8	???°	????11.4
EA (Na 2O)， g/L	????8.2		????9.2		????8.2		????10.7
									Na 2S (Na 2O)， g/L	????2.5		????1.3		????1.3		?????1.3
Based on the sulphidity of AA, %	???31.7		?????13		???14.6		????13.1
									Admittedly contain thing, %	???10.3		???10.6		???11.2		???????-
Admittedly contain thing, g/L	????109		????112		????118		???????-

^*Comprise feed time, be heated to 120 ℃ time and the warm reinforced back time that keeps 120 ℃

Table 3B pulp-making research is summed up

Digester
			Best boiling: new RDH boiling method	R3	?R4
			Baseline boiling: old RDH boiling method	R7	?R8
			Practicable best boiling: improved new-type RDH boiling method	R12
Conditions of cooking

	????R3	????R4	????R7	????R8	?R12
							Warm reinforced
Use Na 2The EA that O represents (g/L)	??????18	????18.6	??????18	????18.6	???17.7
							Admittedly contain thing, %	????14.3	????14.1	????14.7	????14.6	?????15
Hot feed
							EA(g/l)Na 2O	??????20	????19.8	??????18	????18.3	???19.6
Admittedly contain thing, %	????11.9	????12.7	??????17	??????17	???17.3
							The boiling step
The AA charging, %	??????16	??????16	??????10	??????10	?????16
							The H factor	?????475	?????452	?????831	?????832	????494
Maximum temperature ℃,	?????160	?????160	?????170	?????170	????160
							Displacement
Use Na 2The EA that O represents, (g/L)	???????9	????10.1	?????3.7	?????3.5	???10.7
							Admittedly contain thing, %	???????0	???????0	????10.4	????10.3	?????10

Embodiment 1 prepares the paper pulp of following definition in order to study bleaching:

Example	Digester	Card primary	Whiteness, TAPPI
				" the best "	????R3 ????R4	????8.8 ????9.3	?????45.3 ?????45.0
" baseline "	????R7 ????R8	????8.9 ????8.8	?????40.6 ?????41.3
				" practicable the best "	????R10 ????R11 ????R12	????8.5 ????9.2 ????9.3	?????41.5 ?????40.8 ?????41.5

Use (O) (D100) (EO) (D) order bleach five kinds of RDH paper pulp (R3, R4, R7, R8 and R12).Yet each of these five kinds of RDH paper pulp is at first carried out oxygen delignification with the reaction condition shown in the table 4 in the reactor that stirs.

Table 4 oxygen delignification condition

	Preferred example		The baseline example		" practicable " preferred example
						The sample mark	R3	?R4	?R7	?R8	?R12
Kind	Populus	Populus	Populus	Populus	Populus
						The boiling form	RDH	?RDH	?RDH	?RDH	?RDH
Card primary	????8.8	????9.2	????8.9	????8.8	????9.3
						Viscosity, MPa second	???40.7	???44.9	???33.3	???32.2	???32.1
Do not bleach whiteness, %	???45.3	?????45	???40.6	???41.3	???41.5
						O-step: 95 pounds/inch 2, 99 ℃, 12% concentration
NaOH，％	??????2	??????2	??????2	??????2	??????2
						O 2Time, divide	?????60	?????60	?????60	?????60	?????60
Final pH	???12.8	???12.9	???12.5	???12.5	???12.3
						Card primary	????4.7	????5.2	????4.7	????4.5	??????5
Viscosity, MPa second	???14.4	???13.8	???12.6	???13.6	???12.5
						Card uncle's reduction, %	???46.6	???43.5	???47.2	???48.9	?????50
Based on the productive rate of magma, %	???95.2	???95.8	???94.3	???98.8	???94.4

In order to study bleaching, calculate the chlorine dioxide charging in the D100-step among paper pulp R3, R7 and the R12 with the 0.225 card uncle factor.The 0.27 card uncle factor is used for paper pulp R4, R8 and R12.(D100) of the oxygen delignification paper pulp that comes out from these boilings from table 5 to 10 expressions (EO) (D) conditions of bleaching and result below.The concentration of regulating ClO 2 solution by 0.92 factor is with the loss of compensation bleaching period two chlorine monoxid when loading reactor and Polythene Bag.

Pair best RDH paper pulp of table 5 with (O) (D100) (EO) (D) bleach card primary factor=0.225

The sample mark			R3
									Kind			Populus
The boiling form			RDH
									O 2Paper pulp card primary			?????4.7
Viscosity, MPa second			????14.4
									The D-100-step: 30 minutes, 68 ℃, 4.2% concentration
The chlorination factor			????0.23
									ClO 2, % represents with effective chlorine			????1.06
Actual ClO 2, % represents with effective chlorine			????1.15
									Replace %			?????100
H 2SO 4％			?????1.5
									Final pH			???????2
Residue, g/L effective chlorine			????0.14
									The EO-step: 60 minutes, 74 ℃, 10% concentration
NaOH，％			?????0.8
									O 2Pressure, pound/inch 2			??????25
O 2Time, divide			??????15
									Final pH			????12.4
K number (25 Ml)			?????2.3
									Viscosity, MPa second			????13.7
Based on the productive rate of magma, %			????93.5
									The D-step: 74 ℃, 210 minutes, 10% concentration
Sample number	#1	#2	#3	#4	#5	#6	#7	#8
									Use ClO 2The ClO of expression 2，％ *	????0.1	????0.3	?????0.5	????0.7	????0.9	????1.1	????0.9	????1.1
Actual ClO 2， ClO 2％	???0.11	???0.33	????0.54	???0.76	???0.98	????1.2	???0.98	????1.2
									NaOH，％	??????0	??????0	????0.09	???0.16	???0.25	????0.3	???0.33	????0.42
H 2SO 4，％	????0.1	???0.05	???????0	??????0	??????0	??????0	??????0	???????0
									Final pH	????4.1	????3.4	?????3.3	??????3	????2.9	????2.6	????3.6	?????3.7

Residue, % ClO 2Expression	??0.02	??0.01	????0.01	??0.02	??0.02	??0.02	????0	????0
									Whiteness, % ISO	??89.7	??90.4	????91.2	??91.5	??91.6	??0.92	??91.1	?91.3
Viscosity, MPa second	??13.1	?-	???-	??11.2	?-	?-	?-	??9.2

^*Actual ClO ₂Concentration * 0.92

Pair best RDH paper pulp of table 6 with (O) (D100) (EO) (D) bleach card primary factor=0.27

The sample mark	R4
							Kind	Populus
The boiling form	RDH
							O 2Paper pulp card primary	?????5.2
Viscosity, MPa second	????13.8
							The D-100-step: 30 minutes, 68 ℃, 4.2% concentration
The chlorination factor	????0.27
							ClO 2, % represents with effective chlorine	?????1.4
Actual ClO 2, % represents with effective chlorine	????1.53
							Replace %	?????100
H 2SO 4，％	???????2
							Final pH	?????1.9
Residue, the effective Cl of g/L 2	????0.09
							The EO-step: 60 minutes, 74 ℃, 10% concentration
NaOH，％	?????0.8
							O 2Pressure, pound/inch 2	??????25
O 2Time, divide	??????15
							Final pH	????12.5
K number (25 M1)	???????2
							Viscosity, MPa second	????13.3
Based on the productive rate of magma, %	????92.8

The D-step: 74 ℃, 210 minutes, 10% concentration
									Sample number	#1	#2	#3	#4	#5	#6 ??°	#7	#8
Use ClO 2The ClO of expression 2，％ *	????0.1	????0.3	????0.5	????0.7	????0.9	????1.1	????0.9	????1.1
									Actual ClO 2， ClO 2％	???0.11	???0.33	???0.54	???0.76	???0.98	????1.2	???0.98	????1.2
NaOH，％	??????0	??????0	???0.09	???0.16	???0.25	????0.3	???0.33	???0.42
									H 2SO 4，％	????0.1	???0.05	??????0	??????0	??????0	??????0	??????0	??????0
Final pH	????4.3	????3.4	????3.4	????3.2	????2.8	????2.7	????3.7	????3.5
									Residue, % ClO 2Expression	???0.01	???0.01	???0.01	???0.02	???0.01	???0.01	??????0	??????0
Whiteness, %ISO	???89.8	???90.5	???91.2	???91.5	???91.8	???91.8	???91.4	???91.5
									Viscosity, MPa second	???12.5	??-	??-	???11.6	??-	??-	??-	????9.8

^*Actual ClO ₂Concentration * 0.92

Table 7 pair baseline RDH paper pulp with (O) (D100) (EO) (D) bleach card primary factor=0.225

The sample mark	R7
					Kind	Populus
The boiling form	RDH
					O 2Paper pulp card primary	?????4.5
Viscosity, MPa second	????13.6
					The D-100-step: 30 minutes, 68 ℃, 4.2% concentration
The chlorination factor	????0.23
					ClO 2, % represents with effective chlorine	????1.01
Actual ClO 2, % represents with effective chlorine	?????1.1
					Replace %	?????100
H 2SO 4，％	???????2
					Final pH	?????2.7
Residue, the effective Cl of g/L 2	????0.01

The EO-step: 60 minutes, 74 ℃, 10% concentration
								NaOH，％				?????0.8		°
O 2Pressure, pound/inch 2				??????25
								?O 2Time, divide				??????15
Final pH				????12.3
								K number (25 add)				?????2.3
Viscosity, MPa second				????13.3
								Based on the productive rate of magma, %				??????97
The D step: 74 ℃, 210 minutes, 10% concentration
								Sample number	#1		#2	#3	#4	#5	#6
Use ClO 2The ClO of expression 2，％ *		0.1	?????0.3	?????0.5	?????0.7	?????0.9	????1.1
								Actual ClO 2，ClO 2％	?????0.11		????0.33	????0.54	????0.76	????0.98	????1.2
NaOH，％	????????0		???????0	????0.08	?????0.2	????0.33	???0.42
								H 2SO 4，％	??????0.1		????0.05	???????0	???????0	???????0	??????0
Final pH	????????4		?????3.5	?????3.4	?????3.4	?????3.4	????3.8
								Residue, % ClO 2Expression	????????0		???????0	???????0	???????0	???????0	??????0
Whiteness, %ISO	?????87.6		????88.7	????89.7	????90.3	????90.3	????90.6
								Viscosity, MPa second	?????12.6		???-	???-	????11.4	???-	?????9.6

^*Actual ClO ₂Concentration * 0.92

Table 8 pair baseline RDH paper pulp with (O) (D100) (EO) (D) bleach card primary factor=0.27

The sample mark	R8
					Kind	Populus
The boiling form	RDH
					O 2Paper pulp card primary	?????4.7
Viscosity, MPa second	????12.6
					The D-100-step: 30 minutes, 68 ℃, 4.2% concentration
The chlorination factor	????0.27
					ClO 2, % represents with effective chlorine	????1.27
Actual ClO 2, % represents with effective chlorine	????1.38

Replace %					????100
									H 2SO 4，％					??????2
Final pH					????1.9		°
									Residue, the effective Cl of g/L 2					???0.07
The EO-step: 60 minutes, 74 ℃, 10% concentration
									NaOH，％					????0.8
O 2Pressure, pound/inch 2					?????25
									O 2Time, divide					?????15
Final pH					???12.2
									K number (25MI					????2.1
Viscosity, MPa second					???12.6
									Based on the productive rate of magma, %					???94.2
The D-step: 74 ℃, 210 minutes, 10% concentration
									Sample number	????#1			#2	?#3	#4	#5	#6
Use ClO 2The ClO of expression 2，％ *			?0.1	?????0.3	????0.5	?????0.7	?????0.9	????1.1
									Actual ClO 2，ClO 2％		????0.11		????0.33	???0.54	????0.76	????0.98	????1.2
NaOH，％		???????0		???????0	???0.08	?????0.2	????0.33	???0.42
									H 2SO 4，％		?????0.1		????0.05	??????0	???????0	???????0	??????0
Final pH		?????3.6		?????3.1	????3.1	?????3.1	?????3.2	????3.6
									Residue, % ClO 2Expression		???????0		???????0	??????0	???????0	???????0	??????0
Whiteness, %ISO		??????87		????88.7	???89.3	????90.1	????90.5	????90.5
									Viscosity, MPa second		????12.2		??-	?-	????11.2	??-	?????9.5

^*Actual ClO ₂Concentration * 0.92

Table 9 to " practicable " best RDH paper pulp with (O) (D100) (EO) (D) bleach card primary factor=0.225

The sample mark				R12
								Kind				Populus
The boiling form				RDH
								O 2Paper pulp card primary				???????5
Viscosity, MPa second				????12.5
								The D-100-step: 30 minutes, 68 ℃, 4.2% concentration
The chlorination factor				????0.03
								ClO 2, % represents with effective chlorine				????1.13
Actual ClO 2, % represents with effective chlorine				????1.22
								Replace %				?????100
H 2SO 4，％				?????1.5
								Final pH				???????2
Residue, the effective Cl of g/L 2				????0.04
								The EO-step: 60 minutes, 74 ℃, 10% concentration
NaOH，％				?????0.8
								O 2Pressure, pound/inch 2				??????25
O 2Time, divide				??????15
								Final pH				????12.7
K number (25 MI)				?????2.3
								Viscosity, MPa second				????11.9
Based on the productive rate of magma, %
								The D-step: 74 ℃, 210 minutes, 10% concentration
Sample number	#1		#2	#3	#4	#5	#6
								Use ClO 2The ClO of expression 2，％*		?0.1	?????0.3	?????0.5	?????0.7	?????0.9	????1.1
Actual ClO 2，ClO 2％	??????0.11		????0.33	????0.54	????0.76	????0.98	????1.2
								NaOH，％	?????????0		???????0	????0.08	?????0.2	????0.33	???0.42
H 2SO 4，％	???????0.1		????0.05	???????0	???????0	???????0	??????0
								Final pH	???????4.1		?????3.7	?????3.4	?????3.4	?????3.4	????3.3
Residue, % ClO 2Expression	??????0.01		????0.01	????0.01	????0.01	????0.01	???0.01
								Whiteness, %ISO	??????88.9		??????90	????90.8	??????91	????91.6	???91.8
Viscosity, MPa second	??????11.9		??-	??-	????10.5	??-	????9.4

^*Actual ClO ₂Concentration * 0.92

Table 10 to " practicable " best RDH paper pulp with (O) (D100) (EO) (D) bleach card primary factor=0.27

The sample mark				R12
								Kind				Populus
The boiling form				RDH
								O 2Paper pulp card primary				???????5
Viscosity, MPa second				????12.5
								The D-100-step: 30 minutes, 68 ℃, 4.2% concentration
The chlorination factor				????0.03
								ClO 2, % represents with effective chlorine				????1.35
Actual ClO 2, % represents with effective chlorine				????1.47
								Replace %				?????100
H 2SO 4，％				???????2
								Final pH				?????2.3
Residue, effective chlorine g/L				????0.08
								The EO-step: 60 minutes, 74 ℃, 10% concentration
NaOH，％				?????0.8
								O 2Pressure, pound/inch 2				??????25
O 2Time, divide				??????15
								Final pH				????12.6
K number (25 MI)				?????2.2
								Viscosity, MPa second				????12.2
Based on the productive rate of magma, %				?????-
								The D-step: 74 ℃, 210 minutes, 10% concentration
Sample number	#1		#2	#3	#4	#5	#6
								Use ClO 2The ClO of expression 2，％ *		0.1	?????0.3	?????0.5	?????0.7	?????0.9	????1.1
Actual ClO 2，ClO 2％	?????0.11		????0.33	????0.54	????0.76	????0.98	????1.2
								NaOH，％	????????0		???????0	????0.08	?????0.2	????0.33	???0.42
H 2SO 4，％	??????0.1		????0.05	???????0	???????0	???????0	??????0
								Final pH	??????3.9		?????3.4	?????3.3	?????3.3	?????3.3	????3.2
Residue, % ClO 2Expression	?????0.01		????0.01	????0.01	????0.01	???????0	???0.01
								Whiteness, %ISO	?????88.9		??????90	????90.8	????91.1	????91.5	???91.8
Viscosity, MPa second	?????12.4		??-	?-	????10.7	??-	????9.5

^*Actual ClO ₂Concentration * 0.92

Shown in Fig. 5 and 5A, use the higher card uncle factor as if can not reduce the demand of chlorine dioxide in the D1-step.When the chlorine dioxide charging that equates, preferred example RDH paper pulp (R3 and R4) is than high 1.5 to 2 points of whiteness of the routine RDH paper of baseline oar (R7 and R8).

Find out that from Fig. 6 and 6A practicable preferred example RDH paper oar (R12) has produced the middle whiteness between preferred example RDH paper oar (R3) and baseline example paper oar (R7).

Fig. 7 and 7A represent that practicable preferred example RDH paper oar has provided the middle whiteness between preferred example RDH paper oar (R4) and baseline example RDH paper oar (R8).

By the research to the bleaching of paper oar, following table 11 has been listed these results' summary.Bleaching the easiest paper oar is preferred example paper oar.Bleaching the most difficult paper oar is baseline example paper oar, and the bleaching of practicable preferred example paper oar is between last two examples.The result shows: high basicity (add white liquid in temperature, hot feed pattern and boiling stage, active alkalinity is 15%AA-35%AA) and low boiling temperature (about 150 ℃-167 ℃) are combined the bleaching property that has improved the paper oar, therefore improved final whiteness.Should be noted that at the RDH digestion process and should keep black liquor intensity.

Table 11 bleaching research is summed up

Digester

Best digester: new RDH boiling method	????R3	????R4
Baseline digester: old RDH boiling method	????R7	????R8
Practicable best digester: improved new RDH boiling method	???R12

The bleaching results card uncle factor: at D (100%ClO ₂Replacement) in is 0.225

Final whiteness, %ISO

	ClO in the last D step 2Material, %
							?????0.1	?????0.3	?????0.5	?????0.7	?????0.9	????1.1
	R3 (best digester)	????89.7	????90.4	????91.2	????91.5	????91.6							?????92
R12 (practicable best digester)							????88.9	??????90	????90.8	??????91	????91.6	???91.8
	R7 (baseline digester)	????87.6	????88.7	????89.7	????90.3	????90.3							???90.6

The card uncle factor: D (100%ClO ₂Replacement) in is 0.27

Final whiteness, %ISO

	ClO in the last D step 2Material, %
							?????0.1	?????0.3	?????0.5	?????0.7	?????0.9	?????1.1
	R4 (best digester)	????89.8	????90.5	????91.2	????91.5	????91.8							????91.8
R12 (practicable best digester)							????88.9	??????90	????90.8	????91.1	????91.5	????91.8
	R8 (baseline digester)	??????87	????88.7	????89.3	????90.1	????90.5							????90.5

Should understand, be conspicuous to the various changes and modifications of this preferred embodiment described here for those prior aries.Can without departing from the spirit and scope of the present invention and under the situation that does not reduce its attendant advantages, carry out these changes and improvements.Therefore, mean that appended claim has covered these changes and improvements.

Claims (11)

1, uses in the batch cooking method of quick displacement heating with preparation delignification paper pulp type a kind of, wherein being replaced and collect holding vessel (24 by the heated effluent that in digester (10), produces with a large amount of cellulosic materials of cooking liquor boiling, 28,58) in, so that store and use cellulosic material before the heat of this heated effluent comes the boiling of preliminary treatment other, this improvement comprises:

The processing stage of the warm and hot black liquor of this cooking process and the boiling stage add white liquid, this total white liquid has the distribution charging of an about 15%-35%AA; With

In actual digestion process with 150 ℃ of-175 ℃ of temperature cooking cellulose materials.

2, the process of claim 1 wherein liquid or NaOH solution join in warm black liquor (temperature is 90 ℃-150 ℃) and the hot black liquor (150 ℃-168 ℃ of temperature) with predetermined amount in vain.

3, the method for claim 1 comprises white liquid or NaOH solution are added in the cold black liquid (temperature is 70 ℃-90 ℃).

4, the process of claim 1 wherein preferred total white liquid charging＞20%AA.

5, the process of claim 1 wherein that preferred boiling temperature is 155 ℃-168 ℃.

6, a kind of preparation can be bleached the method for grade paper pulp, comprises the following steps:

(a) add wood chip to digester (10);

(b) be lower than under the temperature of boiling temperature with the mixture pre-treatment of chips of warm black liquor with white liquid;

(c) from digester (10), replace this mixture with at least a mixture of hot black liquor and Re Bai liquid;

(d) rising digester (10) temperature is to about 150 ℃-175 ℃ boiling temperature;

(e) keep said temperature, finished by boiling up to wood chip;

(f) use inclusions in the liquid filtrate displacement cooking pot (10) that obtains from pulp washing; With

(g) by executing air pressure to digester (10) inside or pumping inclusions in the emptying digester (10).

7, the method for claim 6 comprises the mixture pre-treatment of chips with cold black liquid and white liquid (or NaOH solution).

8, the method for claim 6, the total white liquid that wherein is used for the boiling wood chip has the combined feed of a 15%AA-35%AA.

9, the method for claim 8, wherein preferred total white liquid charging＞20%AA.

10, the method for claim 6, wherein preferred boiling temperature is about 155 ℃-168 ℃.

11, the method for claim 6 comprises the step of coming inclusions in the displacement cooking pot (10) with wash engine filtrate and any combination of white liquid (or NaOH solution).

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