WO2000073572A1 - Process for digesting lignocellulose material - Google Patents

Abstract

A continuous process for digesting a lignocellulose material using a two-vessel digestion apparatus, wherein a permeation vessel is installed before a digester, the digester has, from the top towards the bottom thereof, an overhead zone, an upper digestion zone and a lower digestion zone, each zone has a strainer at its bottom, and a black digestion liquor extracted is discharged from at least one strainer to the outside of the digestion system, characterized in that use is made of a chip from a broad-leaved tree or a needle-leaved tree; an alkaline digestion liquid is added at the top of the permeation vessel which liquid contains a polysulfide type sulfur in a concentration of 3 to 20 g/L as sulfur, and contains sulfur in an amount of 45 to 100 wt % and an effective alkali in an amount of 45 to 79 wt %, both percentages being relative to the respective total amounts contained in the alkaline digestion liquid introduced to the above digestion system; an alkaline digestion liquid which contains a specific amount of a quinone compound per the weight of an absolutely dried chip is fed to the permeation vessel or to the upper digestion zone at its bottom. The process can be employed for lowering the kappa value for the same percentage of addition of an effective alkali and also for improving the yield of pulp for the same kappa value.

Description

 Specification

 Cooking method for lignocellulosic material

 The present invention relates to a cooking method for lignocellulosic material, and more specifically, can further improve the pulp yield and further improve the relationship between monovalent kappa and pulp yield, as compared with the conventional cooking method. The present invention relates to a method for cooking lignocellulosic material capable of reducing kappa monovalent at the same effective alkali addition rate and improving pulp yield at the same power kappa. Background art

 The main method of manufacturing chemical pulp that has been industrially implemented so far is alkaline digestion of lignocell mouth material such as wood chips, of which sodium hydroxide and sodium sulfide are the main components. The kraft method using a refining cooking liquor is widely used. Conventionally, as a method for improving the pulp yield, a cooking method in which a quinone compound which is a cyclic keto compound such as anthraquinone sulfonate or anthraquinone-tetrahydroanthraquinone is added to a cooking system as a cooking aid (for example, Japanese Patent Publication No. 55-13998, Japanese Patent Publication No. 57-192, 39, Japanese Patent Publication No. 53-4544, Japanese Patent Publication No. 52-37803 ) It has been known. The quinone compound improves the selectivity of delignification, contributes to the reduction of monovalent kappa of the digested pulp and the improvement of the yield.

A polysulfide cooking method in which an alkaline cooking liquor containing polysulfide is used for cooking is also a very effective method for improving the yield. Polysulfide oxidizes the carboxy terminus of carbohydrates and suppresses the decomposition of carbohydrates by the peeling reaction, thereby contributing to improved yields. The alkaline cooking liquor containing polysulfide is produced by oxidizing an alkaline solution containing sodium sulfide with molecular oxygen such as air in the presence of a catalyst such as activated carbon (for example, Japanese Patent Publication No. 50-4). No. 0 395, JP-A-61-25772, JP-A-61-259,754). According to this method, a polysulfide having a conversion of about 60% and a selectivity of about 60% on a sulfide ion basis and a polysulfide concentration of about 5 g / L (L represents little. The same applies in this specification) Alkaline cooking A liquid can be obtained. However, in this method, thiosulfate ions, which do not contribute to the digestion at all, are produced as by-products, which makes it difficult to produce alkali-rich cooking liquor containing high concentrations of polysulfide with high selectivity. Met.

 On the other hand, PCT International Publication Nos. WO 95/07701 and WO 97Z007 71 describe an electrolytic production method of an alkaline cooking liquor containing polysulfide. According to this method, an alkaline cooking liquor containing a high concentration of polysulfide sulfur can be produced at a high selectivity with extremely low by-product of thiosulfate ion. As another method of obtaining an alkaline cooking liquor containing a high concentration of polysulfide sulfur, there is a method of dissolving molecular sulfur in an alkaline aqueous solution containing sodium sulfide. Further, Japanese Patent Application Laid-Open No. 7-189153 discloses a digestion in which a quinone compound and an alkaline cooking liquor containing polysulfide are used in combination, and Japanese Patent Application Laid-Open No. 57-29690 discloses It discloses the mitigation of the degradation of polysulfide under thermal thermal conditions by quinone compounds.

 By the way, in recent years, pulp strength, which is a problem in the kraft method, has been improved, and a cooking method, which is called the modified craft method (hereinafter referred to as the MCC method), which performs more selective delignification during cooking, has been proposed. . The MCC method differs from the conventional craft method in that the cooking liquor is divided and added to the upper cooking zone at the beginning of cooking and after the cooking temperature reaches the maximum temperature. The feature is that it is implemented. Countercurrent refers to the case where the flow direction of the cooking liquor is from the bottom to the top of the kettle. However, although the pulp strength is improved and the kappa value is reduced in the MCC method, there are problems such as an increase in cooking temperature and an increase in cooking chemicals per lignocellulosic material. It was not connected.

Attempts have been made to add a cyclic keto compound as a cooking aid to the MCC method, which has the feature of having a place to add a cooking liquor to the beginning of a digestion and to a predetermined cooking zone. Japanese Patent Application Laid-open No. Hei 4-209893, Japanese Patent Laid-open No. Hei 4-209988, Japanese Patent Laid-open No. Hei 210-88585, Japanese Patent Laid-open No. Hei 210-9886 The publication discloses a two-vessel type continuous digester. In Japanese Patent Application Laid-Open No. 4-111918, when a cyclic keto compound is added to the MCC digestion liquor, in Japanese Patent Application Laid-Open No. 4-209883, the cyclic keto compound is added at the beginning of the digestion (permeation vessel). In the case where a cyclic keto compound is added to the upper digestion zone or the like, Japanese Patent Application Laid-Open No. In Japanese Patent Application Laid-Open No. Hei 4-209896, when the cyclic keto compound is added to the lower cooking zone, the cyclic keto compound is added to the upper cooking zone and the lower cooking zone at the beginning of the cooking. It discloses the case of addition, but does not describe the difference in effect between each addition method, and it is unclear how to add the quinone compound, which is a cyclic keto compound in polysulfide cooking, more effectively. It is.

 Recently, an improvement method called the Lo—So1ids (registered trademark) method has been proposed to solve the problems of the MCC method. In this method, several portions of the digester are used to extract the cooking black liquor in order to minimize the dissolved organic solids concentration in the majority of the delignification process in the digester. After the temperature reaches the maximum temperature, the cooking liquor is divided and added to the cooking zone, and co-current and counter-current cooking are performed inside the digester. Since the cooking liquor is also added at the bottom of the digester, cooking is also performed at the lower part of the digester, resulting in slower cooking at a lower temperature and longer processing time in the entire digestion zone than before. Become. The extraction strainer at the top of the upper cooking zone, that is, countercurrent cooking, that is, at the bottom of the top zone, or the extraction at the bottom of the lower cooking zone, that is, cocurrent cooking, that is, the upper part of the cooking washing zone that is countercurrent cooking. Most of the cooking black liquor is extracted from the strainer, and the concentration of organic solids in the digester is kept low.

 Cooking chemicals (chemicals for cooking) are also consumed by organic components eluted from the lignocellulosic material in addition to delignification elution reaction of the lignocellulosic material. L o— S o l i d s

In the (registered trademark) method, the digestion liquor containing organic components is extracted from several places in the digester, and the digestion liquor is supplied not only at the beginning of the digestion but also during the digestion so that the black liquor in the digester is supplied. The concentration of dissolved organic matter mainly composed of lignin is reduced, the consumption of cooking chemicals by the dissolved organic matter is suppressed, and the selectivity of delignification during cooking is improved. As a result, improvements in pulp strength, reduction in cooking chemicals used, etc. were achieved.

 However, in the L0-S0 lids (registered trademark) method in a 2-vessel digester, a considerable amount of black liquor is extracted during the course of the polysulfide digestion with the addition of a quinone compound. As a result, quinone compounds, which are expensive cooking aids, are also discharged out of the cooking system, further reducing cooking chemicals, improving pulp yield, and improving the relationship between kappa price and pulp yield. There was a problem at.

Therefore, the present invention solves the above-mentioned problems, and provides a two-vessel digester with a plurality of digesters. Extraction of cooking black liquor from the location and addition of an alkaline cooking liquor to the top of the digester and a predetermined cooking zone, in which the polysulphide cooking, which contributes to an increase in the yield, is carried out. It is an object of the present invention to provide a method for cooking a lignocellulose material that can use a quinone compound as described above more effectively.

 Another object of the present invention is to provide an improved method for further improving pulp yield, further improving the relationship between monovalent kappa and pulp yield, and reducing the amount of chemicals required for cooking and bleaching. That is, an object of the present invention is to reduce kappa monovalent at the same effective alkali addition rate and improve pulp yield at the same power alkali monovalent. Disclosure of the invention

 The present invention is a two-vessel digester in which an infiltration vessel is installed in front of a digester, comprising a top zone, an upper digestion zone, and a lower digestion zone from the top to the bottom inside the digester. Strainers are provided at the bottom of each zone, and at least one of the strainers is used to discharge cooking black liquor extracted from at least one strainer to the outside of the digestion system. Alternatively, use softwood chips.Contain polysulfide sulfur at a concentration of 3 to 20 g ZL as sulfur and 45 to 50% of total cooking active sulfur and total alkali contained in the alkaline cooking liquor introduced into the cooking system. An alkaline cooking liquor containing 100% by weight of cooking-active sulfur and 45-79% by weight of effective alcohol is added at the top of the infiltration vessel, and further dried out. Tsu per flop 0.0 1 to 1.5 wt% of which provides the digestion method lignocellulosic material and supplying the Sseru or the upper cooking zone bottom base penetration alkaline cooking liquor containing a quinone compound. BRIEF DESCRIPTION OF THE FIGURES

 FIG. 1 is a diagram showing an example of a two-vessel digester-type apparatus for performing the digestion method of the present invention.

Explanation of symbols: A overhead zone, B upper digestion zone, C lower digestion zone, D digestion washing zone, E infiltration vessel, 1 wood chip, 2 digester, 3 alkaline digestion liquid supply pipe containing polysulfide, 4 Upper extraction strainer, 5, 7 strainer , 6 Lower extraction strainer, 8 Upper alkaline cooking liquor supply pipe, 9 Lower alkaline cooking liquor supply pipe, 10 and 1 1 Black liquor discharge pipe, 1 2 Cooking pulp discharge pipe, 13 Washing liquid Inlet pipe, 14 and 15 heater, 16 and 16 quinone compound inlet pipe, 17 and 18 extraction conduit, 19 upper cooking circulating fluid conduit, 20 lower cooking circulating fluid conduit, 21 transfer BEST MODE FOR CARRYING OUT THE INVENTION

 The present invention includes a permeation vessel and a digester main body, a top zone, an upper digestion zone, and a lower digestion zone from the top to the bottom inside the digester, and a strainer is provided at the bottom of each zone; and The continuous cooking method uses a 2-vessel digester in which at least one of the strainers extracts cooking liquor extracted from at least one strainer to the outside of the cooking system. Although not required here, black liquor discharged outside the digestion system may be extracted from a strainer installed at the bottom of the tower top zone. Also, although not essential here, it is preferred to arrange a digestion wash zone below the lower digestion zone of the black liquor digester.

In the present invention, different cooking compositions of different compositions are added from the top of the infiltration vessel, the upper cooking zone and elsewhere. Examples of the alkaline cooking liquor used in the present invention include a solution mainly composed of polysulfide and sodium hydroxide, a solution mainly composed of sodium hydroxide and sodium sulfide, or a solution mainly composed of sodium hydroxide. Etc. are used. The total amount of chemicals contained in the alkaline cooking liquor introduced into the digestion system from each location is 10 to 25% by weight of effective alkali (2 for absolutely dry chips supplied to the vessel digester). N weight _^0/0 of a ₂ 0), is from 1 to 1 0 wt% in the digestion sulfur-content (wt% sulfur for the bone-dry chips to be supplied to the secondary base Sseru digester).

In the present invention, as the first cooking liquor, an alkaline solution containing polysulfide sulfur at a concentration of 3 to 20 g ZL as sulfur is supplied to the top of the permeation vessel. The concentration of polysulfide sulfur is preferably between 8 and 8 g ZL. While polysulfides contribute to increased yields through carbohydrate protection, they lack stability at high temperatures (above 120 ° C) and decompose at the highest cooking temperature with consumption of sodium hydroxide. When the alkaline cooking liquor containing polysulphide is added to the L 0 — S 0 lids (registered trademark) method in the 2-vessel digester of the present invention in a divided manner during the cooking, it is supplied during the cooking. In this case, the polysulfide is immediately exposed to high temperature, is decomposed, and the yield improvement effect cannot be sufficiently obtained.

 Therefore, in the present invention, it is necessary to add polysulfide to the top of the permeation vessel before the digestion reaches the maximum temperature, to permeate the chips, and to react. The polysulfide sulfur concentration is within the above concentration range necessary to obtain the effect of improving the yield.

That is, it is added as an alkaline solution containing polysulfide sulfur at a concentration of 3 to 20 gZL as the sulfur content. If the concentration of polysulfide sulfur in the first cooking liquor is less than 3 g ZL, little contribution to the increase in yield appears, and if it exceeds 20 g ZL, it cannot contribute to the carbohydrate protection reaction, and the remaining polysulfite As the cooking process reaches the maximum temperature, it undergoes decomposition and at the same time consumes the sodium hydroxide required for the cooking process, making it impossible to secure the alkali content required for the cooking process. The price is also very high.

 As the alkaline cooking liquor containing the polysulfide used in the present invention, a force s' which can be obtained by a conventional air oxidation method, and a part of the polysulfide is converted to sodium thiosulfate due to the air oxidation of the polysulfide. A solution containing sulfide ions such as sodium hydroxide and sodium sulfide, or sodium-carbonate and sodium sulfide as main components is preferred because of disadvantages such as side reactions. O method of electrochemically oxidizing sulfide ions in the gas, that is,

 As the electrolysis method used in the present invention, preferably, the following electrolysis method can be applied [(A) Japanese Patent Application No. 10-166636, (B) Japanese Patent Application No. — 5101-6, (C) Japanese Patent Application No. 111-151033). These were developed earlier by the present inventors and others, and regarding the electrolysis method, the configuration of the anode, the conditions for disposing the anode in the anode chamber, the pressure conditions between the power source chamber and the anode chamber, and others. It pursues and studies on the various requirements of the above, and finds out important requirements for obtaining an effective effect, such as extremely reducing the by-product of thiosulfate ion.

Here, the polysulfide sulfur (PS—S) refers to, for example, sulfur having a valence of 0 in sodium polysulfide Na ₂ SX, that is, sulfur for (X—1) atoms. In addition, the sulfur with the oxidation number of 12 in polysulfide ion (polysulfide) In this specification, the equivalent of sulfur (S x ² — or Na ₂ S x 1-sulfur sulfur) and sulfide ion (S ^2- ) is referred to as Na ₂ S-form sulfur as appropriate. To And in terms of this, the Porisarufua Lee de means a combination of the Porisarufua Lee Dosarufa and N a ₂ S Tai硫yellow, and N a ₂ S state sulfur and sodium sulfide (N a ₂ S) N The Na ₂ S portion of a ₂ SX, and the digestion-active sulfur portion refers to the sum of polysulfide sulfur and Na ₂ S-state sulfur among the sulfur components that contribute to the cooking reaction. .

(A) The technology of Japanese Patent Application No. 10-16663 / 74 is based on a three-dimensional physically continuous mesh composed of nickel or nickel alloy containing at least 50% by weight of nickel. It has the structure and anode surface area of anodic per unit volume of de chamber 5 0 0~2 0 0 0 0 m 2 / m 3 and is anodic chamber disposing a porous anodic, the force Sword A solution containing sulfide ions is introduced into the anode chamber of an electrolytic cell having a diaphragm that separates the cathode chamber, the anode chamber, and the cathode chamber to be provided, and the polysulfide is introduced by electrolytic oxidation. This is a method for producing polysulfide, which is characterized by obtaining ON (polysulfide ion). According to this method, it is possible to produce a cooking liquor containing a high concentration of polysulfide sulfur while maintaining a high selectivity with extremely low by-products of thiosulfate ions. By using cooking liquor for cooking, pulp yield can be effectively increased. Also, unlike an aggregate of fibers, the anode is a physically continuous network structure, which can lower the cell voltage, thereby reducing operating costs. Further, since the anode used in this technique has good electric conductivity, the porosity of the anode can be increased, and the pressure loss can be reduced.

(B) The technology of Japanese Patent Application No. 1 1—5 1 0 16 uses the anode node room where the porous anode is arranged, the force node room where the force node is arranged, and the anode node room and the force node room. This is a method for producing polysulfides in which a solution containing sulfide ions is introduced into an anode chamber of an electrolytic cell having a partitioning membrane, and polysulfide ions are obtained by electrolytic oxidation. This is a method for producing polysulfide, which is characterized by being higher than the pressure in the anode chamber. According to this method, a cooking liquor having extremely low by-products of thiosulfate ion, containing a high concentration of polysulfide-sulfide 7, and having a large amount of residual Na ₂ S-form is selected. It is possible to produce pulp at low power while maintaining the selectivity. The rate can be increased effectively.

 In this technique, the electrolysis operation is performed under conditions where the pressure in the force source chamber is greater than the pressure in the anode chamber. The electrolytic cell generally has a structure in which a diaphragm is sandwiched between an anode and a cathode. From the viewpoint of assembly accuracy and protection of the diaphragm, anode and

-They are placed relatively far apart from each other. Specifically, a distance of about several mm is often provided. The diaphragm arranged between them approaches the anode side or approaches the cathode side depending on the electrolysis conditions. In this technology, the diaphragm is forced into constant contact with the anode, there is no space between the anode and the diaphragm, and the anode liquid is entirely introduced into the porous anode. It improves current efficiency and other factors. As a means of this, electrolysis is performed under conditions where the pressure in the force chamber is higher than the pressure in the anode chamber. By doing so, the diaphragm is pressed against the anode, so that the anolyte solution can sufficiently flow inside the porous anode, and a high selectivity can be realized. In this technique, as a means of increasing the pressure in the cathode chamber to be higher than the pressure in the anode chamber, the flow rate of the solution (power source liquid) introduced into the force chamber is introduced into the anode chamber. There is a method of increasing the flow resistance of the solution to be discharged, a method of increasing the resistance of the cathode liquid by reducing the diameter of the outlet pipe on the cathode side, and the like.

(C) The technology disclosed in Japanese Patent Application No. 11-501103 is based on an anode chamber in which a porous anode is provided, a power sword chamber in which a power source is provided, and a diaphragm that partitions the anode chamber and the power sword chamber. A method for producing polysulfide, in which a solution containing sulfide ions is introduced into an anode chamber of an electrolytic cell having the same, and polysulfide ions are obtained by electrolytic oxidation, wherein the porous anode is a porous anode. The porous anode is arranged so as to have a void at least partially between the anode and the diaphragm, and the apparent volume of the porous anode is 60% to 99% with respect to the volume of the anode chamber. This is a method for producing a characteristic polysulfide. According to this method, a by-product of thiosulfate ion is extremely small, a high concentration of polysulfide sulfur is contained, and a cooking liquor with a large amount of residual Na ₂ S is maintained at a high selectivity. It can be produced, and the pulp yield can be effectively increased by using the polysulfide cooking liquor thus obtained for cooking. In addition, pressure loss during the electrolysis operation can be reduced, and clogging of SS (suspended matter) can be suppressed.

 In the present technology, the porous anode is disposed so as to have a void in at least a part between the porous anode and the diaphragm, and the apparent volume of the porous anode is reduced by the amount of the anode. It is configured to be 60% to 99% of the volume of the storage chamber. Here, the volume of the anode chamber is the volume of the space defined by the effective energizing surface of the diaphragm and the apparent surface of the portion of the anode liquid flowing farthest from the diaphragm. The gap formed between the anode and the diaphragm may be formed on the entire effective conducting surface of the diaphragm, or may be formed on a part thereof. When there is a possibility that clogging may occur when a solid component having a large particle diameter is mixed in the electrolytic cell, it is preferable that the void is continuous as a flow path. If the apparent volume exceeds 9.9%, the pressure loss during electrolysis is large, and the suspended solids are easily clogged, which is not preferable. If the apparent volume is less than 60%, the amount of the anode liquid flowing through the porous anode becomes too small, and the current efficiency becomes poor. Within this range, the electrolysis operation can be performed with a small pressure loss and without the risk of clogging while maintaining good current efficiency. More preferably, this value is set between 70 and 99%.

Also, in this technology, it has been found that the gap on the diaphragm side exerts an unexpected effect. Almost forces believed to occur on the entire surface of § Roh one cathode electrode reactions porous Ano de in the ^art?, The current tends to flow for better part near the diaphragm Ano de small electrical resistance of the liquid, preferentially The reaction proceeds. Therefore, at this site, the reaction becomes mass transfer-controlled, and by-products such as thiosulfate / oxygen are more likely to be formed, and anodic dissolution is more likely to occur. However, when a gap is provided between the porous anode and the membrane, the linear velocity of the anolyte in the gap increases, and the flow velocity of the anolyte in the gap side of the anode is increased by the flow. Because of the large size, material diffusion in a portion of the anode close to the diaphragm is advantageous, and side reactions can be effectively suppressed. In addition, this gap has the advantage that the flow of the anolyte solution is smooth, and that deposits can be made to collect on the anodic surface of the diaphragm.

These technologies (A) to (C) process white liquor or green liquor in the pulp manufacturing process. The present invention is particularly suitable for producing a polysulfide and obtaining a Na aH solution. In the present invention, a white liquor or a green liquor is introduced into the anode chamber of the electrolytic cell, that is, the anode side, and the polysulfide produced here is introduced. It is used as it is, or after causticizing, by adding it before the chips reach their maximum temperature. It is also used by adding NaOH (containing a small amount of KOH) solution generated in the cathode chamber of the electrolytic cell, that is, on the cathode side, after the chip reaches the maximum temperature.

 Hereinafter, the same applies to the techniques of (B) to (C) which mainly explain the technical content and various aspects of (A) regarding these methods. The alkaline cooking liquor containing sodium hydroxide and sodium sulfide as the main components is used for the anode chamber where the anode is located, the cathode chamber where the cathode is located, and the diaphragm that separates the anode chamber from the cathode chamber. It is continuously supplied to the anode chamber of the existing electrolytic cell.

 In this case, the anode material is not particularly limited as long as it is alkaline and has oxidation resistance, and a nonmetal or metal is used. As the non-metal, for example, a carbon material can be used, and as the metal, for example, a base metal such as nickel, cobalt, or titanium, an alloy thereof, a precious metal such as platinum, gold, or rhodium, or an alloy or oxide thereof be able to. As a structure of the anode, it is preferable to use a porous anode having a physically three-dimensional network structure. Specifically, for example, in the case of a nickel anode material, a porous nickel obtained by applying nickel plating to the skeleton of the foamed polymer material and then firing and removing the internal polymer material can be used.

In the case of the above porous anode having a physically three-dimensional network structure, at least the surface of the anode chamber is made of nickel or a nickel alloy containing nickel at least 50% by weight. has a dimension network structure, and to distribution and surface area of § Roh one de per unit volume of the anodic chamber is 5 0 0 ~ 2 0 0 0 0 m 2 / m 3 porous § Roh one de . Since at least the surface of the anode is nickel or nickel alloy, it has sufficient durability for practical use in the production of polysulfide. The surface of the anode is preferably nickel, and nickel alloy containing nickel of 50% by weight or more can be used, and nickel content is more preferably 80% by weight or more. . Nickel is relatively inexpensive, and its elution potential and oxide formation potential are higher than those of polysulfide sulfathiothiosulfate. It is a suitable electrode material for obtaining polysulfide sulfur by electrolytic oxidation. In addition, since it is porous and has a three-dimensional network structure, it has a large surface area, and when used as an anode, the desired electrolytic reaction occurs on the entire surface of the electrode to suppress the generation of by-products Can be. Further, unlike the aggregate of fibers, the anode has a physically continuous network structure, so that it exhibits sufficient electrical conductivity as an anode and can reduce the IR drop at the anode. Therefore, the cell voltage can be further reduced. In addition, since the anode has good electrical conductivity, it is possible to increase the porosity of the anode and reduce the pressure loss.

§ Roh one de surface area per unit volume of § Roh one de chamber, it is necessary that 5 0 0~ 2 0 0 0 0 m 2 / m 3. Here, the volume of the anode chamber is a volume defined by an effective current-carrying surface of the diaphragm and a current collector of the anode. If the surface area of the anode is smaller than 500 n ^ Zm ³ , the current density on the anode surface will increase, and not only will by-products such as thiosulfate ions be easily generated, but also nickel will be reduced. This is not preferred because it tends to cause the dissolution of the anode. If the surface area of the anode is set to be larger than 2000 mVm ^3, it is not preferable because a problem in electrolysis operation may occur when the pressure loss of the liquid becomes large. § Roh one de surface area per unit volume of § Roh one de chamber, 1 0 0 0~ 1 0 0 0 0 m 2 Zm 3 of a is the more preferred range correct Also, the surface area of the anodic may anode It is preferably 2 to 100 m ² / m ² per unit area of the diaphragm separating the pressure chamber and the force source chamber. More preferably, the surface area of the anode is 5 to 50 m ² Zm ² per unit area of the diaphragm. The average pore size of the mesh of the anode is preferably 0.1 to 5 mm. If the average pore size of the mesh is larger than 5 mm, the anode surface area cannot be increased, the current density on the anode surface increases, and only by-products such as thiosulfate ions are easily generated. In addition, nickel is not preferred because nickel easily dissolves the anode. If the average pore diameter of the mesh is smaller than 0.1 mm, it is not preferable because a problem in electrolysis operation such as an increase in pressure loss of the liquid may occur. More preferably, the average pore size of the anode mesh is 0.2 to 2 mm.

The anode of the three-dimensional network structure has a diameter of the wire material constituting the network of 0.01 to Preferably it is 2 mm. Wires with a diameter of less than 0.01 mm are not preferred because they are extremely difficult to manufacture, costly and difficult to handle. If the diameter of the wire exceeds 2 mm, a large surface area of the anode cannot be obtained, the current density on the anode surface increases, and by-products such as thiosulfate ions are easily generated. I don't like it. It is particularly preferable that the diameter of the filament material constituting the mesh is from 0.02 to Imm.

The anode may be arranged to fill the anode chamber so as to be in contact with the diaphragm, or may be arranged so as to have some gap between the anode and the diaphragm. Since the liquid to be treated needs to flow through the anode, it is preferable that the anode has sufficient voids. In each case, the porosity of the anode is preferably 90 to 99%. If the porosity is less than 90%, the pressure loss at the anode increases, which is not preferable. If the porosity exceeds 99%, it is not preferable because it is difficult to increase the surface area of the anode. It is particularly preferable that the porosity is 90 to 98%. (C) In the technology disclosed in Japanese Patent Application No. 115-1503, when a porous anode is used as an anode, the volume of the anode chamber between the porous anode and the diaphragm, and An extremely small amount of by-products of thiosulfate, a high concentration of polysulfide, and a high selectivity can be obtained for the digestion liquor containing a large amount of residual Na ₂ S form, between the apparent volume of the porous compound and the by-product of thiosulfate. We found that there were important requirements for manufacturing while maintaining, and set those requirements. According to this technique, the above-described various effects can be obtained, for example, the pulp yield can be effectively increased by using the obtained polysulfide cooking liquor for cooking.

It is preferable to operate at a current density of 0.5 to ²⁰ kAZm ² at the diaphragm surface. If the current density at the diaphragm surface is less than 0.5 kA / m ² , unnecessarily large electrolytic equipment is required, which is not preferable. If the current density at the diaphragm surface exceeds ² 0 k A / m 2, not only increases the Chio sulfate, sulfate, by-products such as oxygen, lay preferred because nickel is likely to undergo Ano de dissolution Absent. It is more preferable that the current density at the diaphragm surface is 2 to 15 kA / m ² . Since an anode having a large surface area is used for the area of the diaphragm, it can be operated in a range where the current density on the anode surface is small. Since the anode has a large surface area, the current density on the anode surface can be reduced. When the current density on the surface of the anode is calculated from the surface area of the anode, assuming that the current density on the surface of each part of the anode is uniform, the value is 5 to 300 A / m ^2. It is preferable that Yo more preferable range is 1 0~ 1 5 0 0 A / m 2. If the current density on the anode surface is less than 5 AZm ² , unnecessarily large electrolytic equipment is required, which is not preferable. If the current density at § Roh one de surface exceeds ^{3 0 0 0 A / m 2} , not only the Chio sulphate, Ru increases sulfate, by-products such as oxygen, nickel cause § Roh one de dissolution It is not desirable because it may cause a problem. Unlike the aggregate of fibers, this anode is a physically continuous network structure and has sufficient electrical conductivity, so that the IR drop in the anode is kept small while maintaining the gap of the anode. The rate can be increased. Therefore, the pressure loss of the anode can be reduced.

 It is preferable to maintain the liquid flow in the anode chamber in a laminar flow region with a small flow velocity in order to reduce the pressure loss. However, in the laminar flow, the anolyte solution in the anodic chamber is not agitated, and in some cases, deposits easily accumulate on the diaphragm facing the anodic chamber, and the cell voltage tends to increase with time. In this case, even if the anode fluid flow rate is set to be large, the anode pressure loss can be kept small, so that there is an advantage that the anode fluid near the surface of the diaphragm is agitated and deposits are less likely to accumulate. . The average superficial velocity of the anode chamber is preferably 1 to 30 cmZ seconds. The flow velocity of the force source liquid is not limited, but is determined by the magnitude of the floating force of the generated gas. A more preferable range of the average superficial velocity in the anode chamber is 1 to 15 cmZ seconds, and a particularly preferable range is 2 to 10 cmZ seconds.o

As the cathode material, an alkali-resistant material is preferable. For example, nickel, Raney-nickel, steel, stainless steel and the like can be used. The force source may be a single plate or mesh, or a plurality of layers may be used in a multilayer structure. A three-dimensional electrode combining linear electrodes can also be used. As the electrolyzer, a two-chamber type electrolyzer comprising one anode chamber and one force sword chamber or an electrolyzer combined with three or more chambers is used. Many electrolyzers are monopolar or bipolar Can be arranged in the structure.

 It is preferable to use a cation exchange membrane as a membrane separating the anode chamber and the cathode chamber. Cation exchange membranes guide cations from the anode chamber to the force source chamber, preventing the transfer of sulfide and polysulfide ions. As the cation exchange membrane, a polymer membrane in which a cation exchange group such as a sulfone group or a carboxylic acid group is introduced into a hydrocarbon-based or fluororesin-based polymer is preferable. If there is no problem in terms of alkali resistance and the like, a bipolar membrane, an anion exchange membrane, or the like can be used.

Electrolysis conditions such as temperature, current density, etc. are determined by multi-fluid ion (Sx ²⁾ such as S 2 ² —, S 3 ² ”, S 4 ² —, S 5 ² _ as oxidation products of sulfide ions in the anode. —) In other words, it is preferable to adjust and maintain so that polysulfide ions are generated and thiosulfate ions are not by-produced, so that sodium thiosulfate can be substantially reduced by electrolytic oxidation of sodium sulfide. It is possible to produce a highly efficient cooking solution with a sulfur content of 8 to 20 gZL of polysulfide-ide-sulfur without producing by-products, of course, such as temperature and current density. By selecting the electrolysis conditions, it is possible to produce an alkaline cooking liquor with a polysulfide concentration of less than 8 g / L, and high efficiency with no or little by-product thiosulfate ion In the present invention, the sulfur content is 3 to An alkaline cooking liquor with a polysulfide shark concentration of 20 gZL can be produced.

In the present invention, the cooking liquor is the force to be added by dividing into a plurality of locations of penetration base Sseru and ^digester?, The first cooking liquor is fed to the top of the infiltration vessel. In the present invention, as the first cooking liquor, 45 to 100% by weight, preferably 50 to 100% by weight, based on the total amount introduced into the digestion system (infiltration vessel and digester) is used. it is important that 4 5-79 wt% of effective alkali, is preferred properly be effective Al force Li ^force? supply 50-60% by weight relative to the digester active sulfur, the total amount introduced into the cooking system .

If the sulfur content of the cooking liquor of the first cooking liquor is less than 45% by weight, the first half of the cooking will be lacking in sodium sulfide, the selective delignification will not be performed, and the kappa of the pulp obtained by the cooking will not be obtained. —Increase in value and decrease in yield. Good kappa valency and pulp yield can also be obtained when the cooking-active sulfur content of the first cooking liquor is 100% by weight. Regarding the effective alkali of the first cooking liquor, if it is less than 45% by weight, Shortage, and the yield is greatly impaired. In addition, when the effective alkali of the first cooking liquor exceeds 79%, the effective alkali contained in the following second cooking liquor added during the course of cooking decreases, and the latter half of the cooking falls into a shortage of effective alkali, The kappa monovalent of the resulting pulp will increase and the yield will decrease.

Then, as a second cooking liquor, at the bottom of the upper digestion zone of the digester after the cooking temperature reaches the maximum, alkaline cooking mainly composed of sodium hydroxide and sodium sulfide or sodium hydroxide is used. Liquid is supplied. The sulphidity of the cooking liquor at this time is 0 to 40%. Further, as the third cooking liquor, the same alkaline cooking liquor as the second cooking liquor is supplied from the bottom of the cooking washing zone in the latter half of the cooking. As the second and third cooking liquors, specifically, it is desirable to use a white liquor containing sodium hydroxide and sodium sulfide as a main component. More preferably, a white liquor is formed at the cathode when polysulfide is obtained by electrolysis. Al force Li of cooking liquor force mainly composed of hydroxide of ^sodium? used.

 Thus, in the present invention, first, an alkaline cooking liquor consisting mainly of polysulfide and sodium hydroxide is added together with chips at the top of the permeation vessel, and sodium hydroxide and sodium sulfide are added during the digestion in the digester. The main component of the cooking liquid or sodium hydroxide is the main component of the cooking liquid. The addition of the various types of cooking liquor having different compositions to the digester from a plurality of locations as described above makes the two-vessel digester of the present invention more effective in the cooking method. Polysulfide digestion.

Further, in the present invention, 20 to 60% by volume of the whole digested black liquor sent directly from the digester to the recovery step may be extracted by the strainer at the bottom of the tower top zone and discharged to the outside of the digestion system. If the cooking liquor discharged to the outside of the digestion system at this point is less than 20% by volume of the total cooking liquor, a large amount of dissolved organic matter mainly composed of lignin remains in the digester, and the power after cooking The reduction in kappa price is small, and there is no improvement in the relationship between kappa monovalent and pulp yield. On the other hand, if the black liquor discharged outside the cooking system at this point exceeds 60% of the total black liquor, there will be a shortage of cooking due to a shortage of effective alkali after the upper cooking zone, and the power saliva price will also increase. Next, regarding the addition of the quinone compound in the polysulfide digestion, an effective addition method by the MCC method, the Lo-S01ids (registered trademark) method, etc., was not clear, In the present invention, it is important to enhance the effect of the quinone compound as a cooking aid by conducting the digestion as described above and adding the quinone compound to the top of the infiltration vessel or the bottom of the upper digestion zone of the digester. Do you get it.

Therefore, in the present invention, a quinone compound, per absolute dry chips 0. 0 1 to 1.5 by weight _^0/0, preferably 0. 0 1 to 0.1 5 wt _^0/0, more preferably 0. It is added to the first cooking liquor supplied to the top of the infiltration vessel or the second alkaline cooking liquor supplied to the bottom of the upper cooking zone so as to have a concentration of 0.2 to 0.06% by weight. In order to obtain the effect of the quinone compound, it is preferable that the quinone compound coexist as long as possible with the chips in the digester, and that the quinone compound be added where the delignification reaction in the digestion is in progress.

 In the present invention, an alkaline cooking liquor containing polysulfide is supplied together with chips from the top of the digester. In order to obtain the effect of reducing the decomposition of the polysulfide of the quinone compound disclosed in Japanese Patent Application Laid-Open No. 57-296690, a quinone compound is added so that the quinone compound and the polysulfide coexist as long as possible. The addition position is preferably at the top of the permeation vessel. When the amount of the quinone compound added is less than 0.01% by weight, the amount added is too small, so that the strength of the pulp after digestion is not reduced, and the relationship between the strength value and the pulp yield is improved. Not done. Further, even if the quinone compound is added in an amount exceeding 1.5% by weight, no further reduction of the monovalent value of the rev kappa after the digestion and no improvement in the relationship between the monovalent value of the kappa and the pulp yield are observed.

The quinone compound used is a quinone compound, a hydroquinone compound or a precursor thereof as a so-called known cooking aid, and at least one compound selected from these can be used. These compounds include, for example, anthraquinone, dihydroanthraquinone (for example, 1,4-dihydroanthraquinone), and tetrahydroanthraquinone (for example, 1,4,4a, 9a—tetrahydroanthraquinone, 1 , 2,3,4—tetrahydroanthraquinone, methylanthraquinone (for example, 1—methylanthraquinone, 2-methylanthraquinone), methyldihydroanthraquinone (for example, 2-methyl-1,4—dihydroanthraquinone), methyltetrahithone Quinone compounds such as droanthraquinone (for example, 1-methyl-1,4,4a, 9a-tetrahydrodroanthraquinone, 2-methyl-1,4,4a, 9a-tetrahydroanthraquinone); Trahydroquinone (generally 9, 10—dihydroxian Spiral), main Chilliantrahydroquinone (for example, 2-methylanthrahydroquinone), dihydroanthranidroanthraquinone (for example, 1,4 dihydro-1,9,10-dihydroxy anthracene) or an alkali metal salt thereof (for example, dinatto of anthrahydroquinone) Hydroquinone compounds such as lium salt and 1,4-dihydro 9,10- (dinatrium salt of dihydroxyxanthracene), and precursors such as anthrone, anthranol, methylanthrone, and methylanthranol. These precursors have the potential to convert to quinone or hydroquinone compounds under digestion conditions.

 As the lignocellulose material used in the present invention, coniferous or hardwood chips are used, and any type of tree may be used. For example, conifers include spruce, douglas fir, pine, and cedar, and hardwoods include eucalyptus, beech, and oak.

 FIG. 1 is a diagram showing an example of a two-vessel digester-type apparatus for performing the digestion method of the present invention. This is a preferred embodiment of a two-vessel type continuous digester. The apparatus applied in the present invention is not limited to this embodiment. From the top to the bottom, the digester 2 is divided into 4 zones: top zone A, upper digestion zone B, lower digestion zone (:, and digestion washing zone D. A strainer is provided at the bottom of each zone. Upper extraction strainer 4 at the bottom of the first top zone A4, strainer 5 at the second upper digestion zone B, bottom 5, third lower digestion zone C Lower extraction strainer 6 at the bottom, fourth digestion wash Strainer 7 at the bottom of zone D. In addition, infiltration vessel E is installed in front of digester 2.

 Chip 1 is supplied to the top of the infiltration vessel E. On the other hand, a first alkaline cooking liquor composed mainly of polysulfide and sodium hydroxide is supplied via the supply pipe 3 at the top of the permeation vessel E. At this time, the quinone compound-containing liquid supplied from the quinone compound supply conduit 16 is joined to the alkaline cooking liquor supply pipe 3 containing polysulfide, and supplied at the top of the permeation vessel E. The chips filled at the top of the infiltration vessel E descend with the cooking liquor. The infiltration vessel E is maintained at a relatively low temperature (about 120 ° C) for the purpose of infiltrating the first alcoholic cooking liquor and the quinone compound into the chip. During this time, the first cooking liquor and the quinone compound are effectively penetrated into the chip, causing an initial delignification, and a lignin dissolution output from the chip to the cooking liquor.

The chips and cooking liquor descending from the permeation vessel E pass through the transfer feed pipe 21 Supplied to the top of demolition tank 2 and enters tower zone A. In the top zone A, the chips and the cooking liquor are further heated, delignification proceeds, and lignin elution into the cooking liquor further progresses. A predetermined amount of the digested black liquor containing lignin eluted from the chip is extracted from the upper extraction strainer 4 and sent to the recovery step through the black liquor discharge conduit 10.

 Chips descending from overhead zone A enter upper digestion zone B. In this zone, the chips reach the maximum cooking temperature and delignification proceeds further. The cooking black liquor extracted from the strainer 5 provided at the bottom of the upper cooking zone B is connected to a second cooking liquor supply pipe, that is, an upper total cooking liquor supply pipe 8 in the extract liquid conduit 17. The flowing alkaline cooking liquid containing sodium hydroxide and sodium sulfide or the alkaline cooking liquid mainly containing sodium hydroxide is combined and heated by a heater 14 provided in the flow path.

 This circulating liquid, that is, the upper cooking circulating liquid, is supplied via the upper cooking circulating liquid conduit 19 near the strainer 5 at the bottom of the upper cooking zone B. In the upper digestion zone B, the chips descend from the bottom of the upper extraction strainer 4 toward the upper part of the strainer 5, and during this time, the circulating digest supplied from the circulating fluid conduit 19 near the strainer 5 is extracted at the upper part. It rises toward the strainer 4, and the delignification reaction proceeds by countercurrent cooking by the action of the second cooking liquor. The circulated cooking liquor rising toward the upper extraction strainer 4 is extracted as black liquor from the upper extraction strainer 4 and sent to a recovery step through a black liquor discharge conduit 10.

 The chips delignified in the upper digestion zone B enter the lower digestion zone C below the strainer 5 and receive delignification by co-current digestion. The digested black liquor obtained in this zone is extracted from the lower extraction strainer 6 at the bottom of the lower digestion zone C and sent to the recovery step through the black liquor discharge conduit 11.

Chips descending from lower cooking zone C enter cooking washing zone D. In this zone, the chips undergo countercurrent cooking and delignification proceeds further. The digested black liquor extracted from the strainer 7 near the bottom of the digester provided in the lower part of the digestion washing zone D is sodium hydroxide flowing through the lower alkaline cooking liquor supply pipe 9 in the extract liquid conduit 18. And an alkaline cooking liquor containing sodium sulfide as a main component or an alkaline cooking liquor containing sodium hydroxide as a main component, and are heated by a heater 15 provided in a flow path. This circulation The liquid is supplied near the strainer 7 via the lower circulating liquid conduit 20. In digestion washing zone D, the chips descend from the lower extraction strainer 6 toward the strainer 7, during which time the circulating digestion liquid supplied from the lower circulating fluid conduit 20 near the strainer 7 loses the lower extraction strain. The digested black liquor rises toward the bottom 6 and is extracted from the lower extraction strainer 6 and sent to the recovery step through the black liquor discharge conduit 11. In this zone, the cooking reaction is completed, and pulp is obtained through the cooking pulp discharge pipe 12.

 The temperature in the infiltration vessel E was about 120 ° C, the temperature at the top of the top zone A in the digester 2 was around 120 ° C, and the temperature at the bottom of the top zone was 14 ° C. It is heated to a maximum cooking temperature in the range of 0 to 170 ° C. In the upper digestion zone 8 and the lower digestion zone C, the maximum temperature is kept within the range of 140 to 170 ° C, and in the digestion washing zone D, 140 ° is applied to the bottom of the digestion washing zone D. It decreases to around C. Example

 Hereinafter, the ability to explain the present invention in more detail based on the examples. Of course, the present invention is not limited to these examples. Examples 1 to 8, 11 to 18 and Comparative Examples 1 to 2 and 9 to 11 used hardwood mixed materials, and Examples 9, 10 and Comparative Examples 3 and 4 used softwood mixed chips. It is cooked by the method of the present invention in a digester.

 Cooking was indexed by H-factor (HF). The H-factor is a measure of the total amount of heat applied to the reaction system during the cooking process, and is represented by the following equation in the present invention. Where HF is the H-factor, T is the absolute temperature at a point in time, and dt is a function of time that changes over time due to the temperature profile in the digester. H-factor-1 is calculated by integrating the term on the right-hand side by the integration symbol from the time when the chips and the alkaline cooking liquor are mixed to the time when the cooking ends.

^{HF = i 1 η} ~ '( ^43.20-16 1 1 3 T) dt Test method

In the following, the pulp yield of the obtained unbleached pulp is obtained by measuring the yield of carefully selected pulp from which kashiwa has been removed. Unbleached pulp kappa monovalent is TAPPI test method T 2 3 Performed according to 6 os-76. Quantification of sodium sulfide and polysulfide concentration in terms of sulfur and sulfur in the alkaline cooking liquor was performed according to TAP PI test method T 624 hm-85. The pulp yield was calculated from the carbohydrate yield according to TAPPI test method T 249 hm-85 and the pulp alcohol and benzene extractables according to TAPPI test method T 2040 s-76 and the TAPPI test method T 2220 s- The acid-insoluble lignin content of the pulp performed according to 74 was added. Example 1

Chips obtained by mixing acacia 30, oak 30, and eucalypt 40 at the absolute dry weight% were used for digestion using the continuous digester shown in FIG. Total effective alkali addition rate is 1 1.9, 12.8, 13.6 wt%; was performed in three (pairs bone-dry chip N a ₂ 0 equivalent). The first cooking liquor to be added at the top of the infiltration vessel was a polysulfide sulfa concentration of 4 gZL (equivalent to sulfur) obtained by electrochemically oxidizing an alkaline solution containing sodium hydroxide and sodium sulfide as the main components in the following electrolytic cell. ), 53 wt based on the total amount of the sodium concentration 70 GZL hydroxide (N a ₂ 0 equivalent) and sodium sulfide concentration 22 gZL (Na ₂ 0 equivalent) Al force Li of cooking liquor of the main component, is introduced into the cooking system % Sulfur content (pulping active sulfur content, the same applies hereinafter) and 50% by weight of effective alkali. At that time, the liquid ratio was adjusted to about 2.5 LZkg with respect to the absolutely dry chips, including the moisture brought in by the chips. From the upper extraction strainer, 45% by volume of the total digested black liquor was extracted. At the bottom of the upper cooking zone, a second cooking liquor with 30% sulphidity was added to make 31.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquor of 30% sulphide was added so as to have an effective capacity of 18.4% by weight based on the total amount introduced into the cooking system.

The electrolytic cell was configured as follows. Nickel porous material (Anode surface area per volume of anode chamber: 5600 mm, average pore diameter of mesh: 0.51 mm, surface area to diaphragm area: 28 m ² / m ³ ), force source A two-chamber electrolytic cell composed of an iron metal and a fluororesin-based cation exchange membrane as a diaphragm was assembled.

Hold at 120 ° C for 20 minutes in the infiltration vessel, and from the top of the top zone in the top zone Heated from 120 ° C to 140 ° C in 20 minutes toward the bottom, maintained at 30 ° C and 15 ° C in the upper digestion zone, 120 minutes and 15 ° C in the lower digestion zone Maintain at 2 ° C, and in the digestion washing zone, reduce the temperature from 152 ° C to 140 ° C in 140 minutes from the top to the bottom of the digestion washing zone to reduce the digestion to H-factor 830. went. As a quinone compound, 1,4,4a, 9a-tetrahydroanthraquinone was mixed with the first cooking liquor added at the top of the permeation vessel in an amount of 0.03% by weight based on the absolutely dried chips. Table 1 shows the cooking results. According to this example, compared to Comparative Examples 1 to 4, the kappa value at the same effective alkali addition rate was reduced, and the pulp yield at the same power value was increased.

 Example 2

 Chips used for cooking, total effective alkali addition rate, liquor ratio, production method of first cooking liquor, composition, amount of black liquor extracted from upper extraction strainer, temperature and time of digester, H-factor and quinone compound The addition was performed in the same manner as in Example 1. The first cooking liquor added at the top of the infiltration vessel was such that it contained 72% by weight of sulfur and 70% by weight of the total capacity introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor of 30% sulphide was added so as to be 21.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquor having a sulfuration degree of 30% was added so as to be 8.4% by weight of an effective alkali with respect to the total amount introduced into the cooking system. Table 1 shows the cooking results. According to this example, as compared with Comparative Examples 1 to 4, the pulp value at the same effective alkali addition rate was reduced, and the pulp yield at the same pulp value was increased.

 Example 3

Chips used for cooking, total effective alkali addition rate, liquid ratio, production method of first cooking liquor, composition, amount of cooking black liquor extracted from upper extraction strainer, temperature, time, H-factor and quinone compound of digester Was added in the same manner as in Example 1. The first cooking liquor added at the top of the infiltration vessel was such that it had a sulfur content of 100% by weight and an effective capacity of 50% by weight, based on the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor composed mainly of sodium hydroxide was added so as to have an effective alkali content of 31.6% by weight based on the total amount introduced into the cooking system. At the bottom of the digestion wash zone, a liquid of the same composition as the second digestion liquor was added to make 18.4% by weight of effective alkali based on the total amount introduced into the digestion system. I got calo. Table 1 shows the giraffes. According to the present example, as compared with Comparative Examples 1 to 4, the kappa monovalent at the effective addition rate was reduced and the pulp yield at the same potency was increased.

<< Example 4 >>

 Chips used for cooking, total effective alkali addition rate, liquor ratio, production method of first cooking liquor, composition, amount of black liquor extracted from upper extraction strainer, temperature and time of digester, H-factor and quinone compound The addition was performed in the same manner as in Example 1. The first cooking liquor added at the top of the infiltration vessel was such that it had a sulfur content of 100% by weight and an effective capacity of 70% by weight, based on the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor containing sodium hydroxide as a main component was added so as to have an effective alkali content of 21.6% by weight based on the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquor was added so as to have an effective alkali content of 8.4% by weight based on the total amount introduced into the cooking system. Table 1 shows the cooking results. According to the present example, the pulp number at the same effective power addition rate was reduced and the pulp yield at the same effective power value was increased as compared with Comparative Examples 1 to 4.

 << Example 5 >>

The chips used for cooking, the total effective alkali addition rate, the liquid ratio, the amount of black liquor extracted from the upper extraction strainer, the temperature and time of the digester, the addition of H-factor and quinone compounds were the same as in Example 1. went. The first cooking liquor to be added at the top of the infiltration vessel was a polysulfide sulfur concentration obtained by electrochemically oxidizing an alkaline solution containing sodium hydroxide and sodium sulfide as the main components in the electrolytic cell. O g ZL (terms of sulfur), an alkaline cooking liquor sodium 7 0 g ZL hydroxide (N a ₂ 0 equivalent) and sodium sulfide 1 1 g / L (N a 2 0 equivalent) is the main component, introduced into the cooking system 55% by weight of sulfur and 50% by weight of effective alkali were added to the total amount to be obtained. At the bottom of the upper cooking zone, a second cooking liquor of 30% sulphide was added to make 31.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquid having a sulfuration degree of 30% was added so as to be 18.4% by weight of the effective alkali with respect to the total amount introduced into the cooking system. Table 2 shows the cooking results. According to the present example, the kappa monovalent value at the same effective alkali addition rate was reduced as compared with Comparative Examples 1 to 4, Increased pulp yield at monovalent.

 Example 6

 The chips used for cooking, the total effective alkali addition rate, the liquid ratio, the amount of black liquor extracted from the upper extraction strainer, the temperature and time of the digester, the addition of the H-factor and the quinone compound were the same as in Example 1. The production method and composition of the first cooking liquor were the same as in Example 5. The first cooking liquor added at the top of the infiltration vessel was made up to 74% by weight of sulfur and 70% by weight of effective alkali relative to the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor of 30% sulphide was added to give an effective alkali content of 21.6% by weight, based on the total amount introduced into the cooking system. At the bottom of the digestion washing zone, a liquid having the same composition as the second cooking liquor having a sulfuration degree of 30% was added so as to have an effective alkali of 8.4% by weight based on the total amount introduced into the cooking system. Table 2 shows the cooking results. According to this example, as compared with Comparative Examples 1 to 4, kappa monovalent at the same effective alkali addition rate was reduced, and the yield of kappa at the same kappa monovalent was increased.

 Example 7

 The chips used for cooking, the total effective alkali addition rate, the liquid ratio, the amount of black liquor extracted from the upper extraction strainer, the temperature and time of the digester, the addition of the H-factor and the quinone compound were the same as in Example 1. The production method and composition of the first cooking liquor were the same as in Example 5. The first cooking liquor added at the top of the infiltration vessel was 100% by weight sulfur and 50% by weight effective alkali relative to the total amount introduced into the digestion system. At the bottom of the upper cooking zone, a second cooking liquor composed mainly of sodium hydroxide was added so as to be 31.6% by weight of the effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquor was added so as to have an effective alkali content of 18.4% by weight based on the total amount introduced into the cooking system. Table 2 shows the cooking results. According to this example, as compared with Comparative Examples 1 to 4, the kappa monovalent value at the same effective alkali addition rate was reduced, and the pulp yield at the same kappa value was increased.

 Example 8

The chips used for cooking, the total effective alkali addition rate, the liquid ratio, the amount of black liquor extracted from the upper extraction strainer, the temperature and time of the digester, the addition of H-factor and quinone compounds were the same as in Example 1. The method and composition of the first cooking liquor were the same as in Example 5. Soak First cooking liquor added at the top of the permeable vessel was set to be 1 0 0 by weight _^0/0 of sulfur and 7 0% by weight of the active Al force Li based on the total amount introduced into the digester system. At the bottom of the upper cooking zone, a second cooking liquor containing sodium hydroxide as a main component was added so as to be 21.6% by weight of an effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the digestion zone, a liquid having the same composition as the second cooking liquor was added so as to have an effective alkali content of 8.4% by weight based on the total amount introduced into the cooking system. Table 2 shows the cooking results. According to this example, the kappa monovalent at the same effective alkali addition rate was reduced and the pulp yield at the same kappa monovalent was increased as compared with Comparative Examples 1 to 4.

 Example 9

Radians evening Pine 4 0, using the chip combined mixed in the absolute dry weight _^0/0 of Douglas Fir 3 0 and larch 3 0 to digestion using a continuous digester shown in Figure 1. The total effective Al Chikarari添pressure ratio 1 4 5 1 6 5 1 8 5 wt%; was performed in three (pairs bone-dry chip N a ₂ 0 equivalent).... The production method and composition of the first cooking liquor used for cooking and the amount of black liquor extracted from the upper extraction strainer were the same as in Example 1. The first cooking liquor added at the top of the infiltration vessel was made up to 53% by weight sulfur and 50% by weight available alkali relative to the total amount introduced into the cooking system. At that time, the liquid ratio was about 3.5 LZ kg for the absolutely dry chip, including the moisture brought in by the chip. At the bottom of the upper cooking zone, a second cooking liquor of 30% sulphide was added to make 31.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the digestion washing zone, a liquid having the same composition as the second cooking liquor having a sulfidity of 30% was added so as to be 18.4% by weight of an effective alkali with respect to the total amount introduced into the digestion system. 1,4,4a, 9a-Tetrahydroanthraquinone as a quinone compound was mixed with the first cooking liquor to be added in a 0.05% by weight permeation vessel to the absolutely dry chips. In the infiltration vessel, the temperature is kept at 120 ° C for 30 minutes, and in the top zone, the temperature is raised from 120 ° C to 140 ° C in the top zone from the top to the bottom in 30 minutes. In the upper digestion zone, the temperature was maintained at 156 ° C. for 50 minutes, in the digestion washing zone, the temperature was maintained at 156 ° C. for 160 minutes, and in the digestion washing zone, 1 min. The temperature was lowered from 56 ° C to 140 ° C in 170 minutes, and the digestion was carried out to H-factor of 1400. Table 4 shows the cooking results. According to this example, compared with Comparative Examples 5 to 8, the kappa monovalent value at the same effective alkali addition rate was reduced, and the pulp yield at the same power value was increased. Example 10

 Chips used for digestion, total effective alkali addition rate, liquid ratio and digester temperature, time,

The addition of the H-factor and the quinone compound was the same as in Example 9, the amount of the cooking black liquor extracted from the upper extraction strainer was the same as in Example 1, and the production method and composition of the first cooking liquor were as in Example 5. The same was done. The first cooking liquor added at the top of the permeation vessel was added so as to have a sulfur content of 100% by weight and an effective energy of 50% by weight based on the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor composed mainly of sodium hydroxide was added so as to be 31.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquor was added so as to be 18.4% by weight of effective alkali with respect to the total amount introduced into the cooking system. Table 4 shows the cooking results. According to this example, as compared with Comparative Examples 5 to 8, the kappa monovalent at the same effective alkali addition rate was reduced, and the pulp yield at the same potency was increased.

 Example 1 1

Chips used for cooking, total effective alkali addition rate, liquid ratio, method of preparing first cooking liquor, composition, amount of black liquor extracted from upper extraction strainer, temperature and time of digester One was performed in the same manner as in Example 1. The quinone compound, 1, 4, 4 a, 9 a - mixed to 0 Tetorahi mud anthraquinone against the bone-dry chip 0 3 second cooking liquor added weight _^0/0 by cooking zone Ichin bottom. Was. The first cooking liquor added at the top of the infiltration vessel was such that the total sulfur introduced into the cooking system was 53% by weight of sulfur and 50% by weight of effective aluminum. At the bottom of the upper cooking zone, a second cooking liquor of 30% sulphide was added to make 31.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquid having a sulfuration degree of 30% was added so as to be 18.4% by weight of an effective alkali with respect to the total amount introduced into the cooking system. Table 6 shows the cooking results. According to this example, compared to Comparative Examples 2 and 9 to 11, kappa monovalent was reduced at the same effective alkali addition rate and pulp yield was increased at the same potter value o

 Example 1 2

Chips used for cooking, total effective alkali addition rate, liquor ratio, production method of first cooking liquor, composition, amount of cooking black liquor extracted from upper extraction strainer, temperature, time and H-factor of digester In the same manner as in Example 1, 1,4,4a, 9a-tetrahide anthraquinone as a quinone compound was added to the absolutely dry chip at the top of a 0.03% by weight permeation vessel. It was mixed into the first cooking liquor. The first cooking liquor added at the top of the infiltration vessel was such that it contained 72% by weight of sulfur and 70% by weight of the total volume introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor of 30% sulphide was added to make 21.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the digestion washing zone, a solution having the same composition as the second digestion solution having a sulfuration degree of 30% was added so as to be 8.4% by weight of the effective alkali with respect to the total amount introduced into the digestion system. The digestion results are shown in Table 6. According to this example, as compared with Comparative Examples 2 and 9 to 11, the pulp number at the same effective alkali addition rate was reduced, and the pulp yield at the same lip number was increased.

 Example 13

 The chips used for cooking, total effective alkali addition rate, liquor ratio, production method and composition of the first cooking liquor, amount of cooking black liquor extracted from the upper extraction strainer, temperature, time and H-fatter of the digester are as follows: In the same manner as in Example 1, the quinone compound was added in the same manner as in Example 11. The first cooking liquor added at the top of the osmotic vessel was 100% by weight sulfur and 50% by weight effective alkali relative to the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor composed mainly of sodium hydroxide was added so as to have an effective alkali content of 31.6% by weight based on the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquor was added so as to be 18.4% by weight of an effective alkali with respect to the total amount introduced into the cooking system. Table 6 shows the cooking results. According to this example, as compared with Comparative Examples 2 and 9 to 11, kappa monovalent at the same effective alkali addition rate was reduced, and pulp yield at the same potency was increased.

 Example 14

The chips used for cooking, total effective alkali addition rate, liquor ratio, method and composition of the first cooking liquor, amount of black liquor extracted from the upper extraction strainer, digester temperature, time and H-factor were implemented. As in Example 1, the addition of the quinone compound was performed as in Example 11. The first cooking liquor added at the top of the osmotic vessel was 100% by weight sulfur and 70% by weight effective alkali relative to the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor composed mainly of sodium hydroxide is added to the total amount introduced into the cooking system. It was added so as to have an effective alkali content of 21.6% by weight. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquor was added so as to be 8.4% by weight of an effective alkali with respect to the total amount introduced into the cooking system. Table 6 shows the cooking results. According to this example, as compared with Comparative Examples 2 and 9 to 11, kappa monovalent at the same effective alkali addition rate was reduced, and pulp yield at the same potency was increased.

 Example 15

 The chips used in the digestion, the total effective alkali addition rate, the liquor ratio, the amount of the digested black liquor extracted from the upper extraction strainer, the temperature, time and H-factor of the digester were the same as in Example 1, and the first digestion was carried out. The production method and composition of the liquid were the same as in Example 5, and the addition of the quinone compound was performed as in Example 11. The first cooking liquor added at the top of the permeation vessel was added so as to have a sulfur content of 55% by weight and an effective energy of 50% by weight based on the total amount introduced. At the bottom of the upper cooking zone, a second cooking liquor of 30% sulphide was added to make 31.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the digestion zone, a liquid having the same composition as the second cooking liquor having a sulfidity of 30% was added so as to be 18.4% by weight of an effective alkali with respect to the total amount introduced into the cooking system. Table 7 shows the cooking results. According to this example, as compared with Comparative Examples 2 and 9 to 11, the monovalent value of copper at the same effective alkali addition rate was reduced, and the pulp yield at the same monovalent value of saliva was increased.

 Example 16

The chips used in the digestion, the total effective alkali addition rate, the liquor ratio, the amount of the digested black liquor extracted from the upper extraction strainer, the temperature, time and H-factor of the digester were the same as in Example 1, and the first digestion was carried out. The production method and composition of the liquid were the same as in Example 5, and the addition of the quinone compound was performed as in Example 11. The first cooking liquor added at the top of the infiltration vessel was such that it contained 74% by weight of sulfur and 70% by weight of the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor of 30% sulphide was added to give an effective alkali content of 21.6% by weight, based on the total amount introduced into the cooking system. At the bottom of the digestion washing zone, a liquid having the same composition as the second cooking liquor having a sulfidity of 30% was added so as to be 8.4% by weight of the effective alkali with respect to the total amount introduced into the digestion system. Table 7 shows the cooking results. According to this example, the kappa monovalent value at the same effective alkali addition rate was reduced and the pulp yield at the same power value was increased compared to Comparative Examples 2, 9 to 11. Example 1

 The chips used for the digestion, the total effective alkali addition rate, the liquor ratio, the amount of the digested black liquor extracted from the upper extraction strainer, the temperature and time of the digester, and the フ ァ ク タ -factor were the same as in Example 1. The production method and composition of the liquid were the same as in Example 5, and the addition of the quinone compound was performed as in Example 11. The first cooking liquor added at the top of the infiltration vessel was such that 100% by weight of sulfur and 50% by weight of the effective amount were based on the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor consisting mainly of sodium hydroxide was added to make the effective alkali 31.6% by weight based on the total amount introduced into the cooking system. At the bottom of the digestion washing zone, a liquid having the same composition as the second cooking liquor was added so as to have an effective alkali content of 18.4% by weight based on the total amount introduced into the cooking system. Table 7 shows the cooking results. According to this example, as compared with Comparative Examples 2 and 9 to 11, the monovalent value of copper at the same effective alkali addition rate was reduced, and the pulp yield at the same strength value of pulp was increased.

 Example 18

 The chips used for the digestion, the total effective alkali addition rate, the liquor ratio, the amount of the digested black liquor extracted from the upper extraction strainer, the temperature and time of the digester, and the フ ァ ク タ -factor were the same as in Example 1. The production method and composition of the liquid were the same as in Example 5, and the addition of the quinone compound was performed as in Example 11. The first cooking liquor added at the top of the infiltration vessel was such that it had a sulfur content of 100% by weight and an effective capacity of 70% by weight, based on the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor composed mainly of sodium hydroxide was added so as to be 21.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquor was added so as to have an effective alkali content of 8.4% by weight based on the total amount introduced into the cooking system. Table 7 shows the cooking results. According to this example, as compared with Comparative Examples 2 and 9 to 11, the monovalent value of copper at the same effective alkali addition rate was reduced, and the pulp yield at the same strength value of pulp was increased.

 Example 19

The chips used for the cooking and the total effective alkali addition rate were the same as in Example 1. The digester used a 2.5-liter autoclave that turned upside down in an air bath where an arbitrary temperature profile could be set. This device has a valve that can extract liquid in the autoclave and a valve that can inject liquid from outside into the autoclave. Cooking Explaining the temperature profile, the digestion starts at room temperature, rises to 140 ° C in 30 minutes, then to 160 ° C over 60 minutes, and then 250 minutes and 160 ° C. It was kept at C and cooked to H-factor of 1400. At the start of the digestion, at room temperature, together with the chips, an alkaline solution mainly containing sodium hydroxide and sodium sulfide was introduced into the electrolytic cell, and the sodium sulfide in the alkaline solution was electrochemically oxidized. obtained was poly Sarufai Dosarufa concentration 4 GZL (terms of sulfur), the first alkaline sodium concentration 70 GZL hydroxide (N a ₂ 0 equivalent) and sodium sulfide concentration 22. 6 gZL (N a ₂ 0 equivalent) is the main component The cooking liquor was added so as to have a sulfur content of 53% by weight and an effective alkali content of 50% by weight based on the total amount introduced into the cooking system, and heating was started. At that time, the liquid ratio was adjusted to 2.5 LZkg with respect to the absolutely dry chips by combining with the moisture brought in by the chips. When the temperature reached 140 ° C in 30 minutes after the start of the temperature rise, 45% by volume of the whole digested black liquor was extracted from the autoclave. After the extraction, a second cooking liquor having a sulfide degree of 30%, which has been heated to 90 ° C in advance, is heated in a digester with 31.6% by weight of an effective alkali with respect to the total amount introduced into the digester. It was added so that the liquid ratio became 2.5 L / kg. Further, at 240 minutes from the start of the cooking, a liquid having the same composition as the second cooking liquid having a sulfide degree of 30%, which had been heated to 90 ° C in advance, was added to the total amount introduced into the cooking system. 18.4% by weight of effective alkali was added. The quinone compound was mixed with 0.05 weight _^0/0 to the second cooking liquor tetrahydroanthraquinone against bone-dry chip. Table 9 shows the cooking results. According to this example, as compared with Comparative Examples 12 to 15, kappa monovalent at the same effective alkali addition rate was reduced, and pulp yield at the same kappa monovalent was increased.

 Example 20

The chips used for the cooking and the total effective alkali addition rate were the same as in Example 1, and the cooking equipment, the method for preparing the first cooking liquor, the composition, the cooking temperature and time, the addition of the H-factor and the quinone compound were the same as in Example 1. Performed in the same manner as 9. At the start of cooking, the first cooking liquor was added together with chips at room temperature so as to be 72% by weight of sulfur and 70% by weight of effective alkali with respect to the total amount introduced into the cooking system, and the temperature was raised. At this time, the liquid ratio was adjusted to 2.5 LZkg with respect to the absolutely dry chips, in accordance with the water content brought into the chips. When the temperature reached 140 ° C in 30 minutes after the start of the temperature rise, 45% by volume of the whole digested black liquor was extracted from the autoclave. After extraction, the second cooking liquor with 30% sulphide, previously heated to 90 ° C, 21.6% by weight of an effective alkali was added so that the liquid ratio in the digester became 2.5 L / kg. Further, at 240 minutes after the start of the cooking, a liquid having the same composition as the second cooking liquid having a sulfide degree of 30%, which had been heated to 90 ° C in advance, was added to the total amount introduced into the cooking system by 8%. 4% by weight of effective alkali was added. Table 9 shows the cooking results. According to this example, compared to Comparative Examples 12 to 15, the kappa monovalent value at the same effective alkali addition rate was reduced, and the pulp yield at the same power value was increased.

 Example 2 1

 The chips used for the cooking, the total effective alkali addition rate were the same as in Example 1, and the cooking equipment, the preparation method of the first cooking liquor, the composition, the cooking temperature and time, the addition of the H-factor and the quinone compound were the same as in Example 1. Performed in a similar manner to 19. At the start of cooking, the first cooking liquor is added together with the chips at room temperature so as to be 100% by weight of sulfur and 50% by weight of effective alkali with respect to the total amount introduced into the cooking system, and heating is started. did. At that time, the liquid ratio was adjusted to 2.5 LZkg with respect to the absolutely dry chips by combining the water content brought into the chips. When the temperature reached 140 ° C. in 30 minutes after the start of heating, 45% by volume of the whole digested black liquor was extracted from the autoclave. After the extraction, a second cooking liquor containing sodium hydroxide as a main component, which has been heated to 90 ° C in advance, is fed into the digester with 31.6% by weight of an effective alkali based on the total amount introduced into the cooking system. Was added so that the solution ratio became 2.5 LZkg. Further, at 240 minutes after the start of the cooking, a liquid having the same composition as the second cooking liquid having a sulfide degree of 30%, which was previously heated to 90 ° C, was added to the total amount introduced into the cooking system. 18.4% by weight of effective alkali. Table 9 shows the cooking results. According to this example, as compared with Comparative Examples 12 to 15, the pulp number at the same effective altar added calo rate was reduced, and the pulp yield at the same effective lip number was increased. Example 22

The chips used for the cooking, the total effective alkali addition rate were the same as in Example 1, and the cooking equipment, the preparation method of the first cooking liquor, the composition, the cooking temperature and time, the addition of the H-factor and the quinone compound were the same as in Example 1. Performed in a similar manner to 19. At the start of cooking, at room temperature, the first cooking liquor was added together with the chips so as to have a sulfur content of 100% by weight and an effective amount of 70% by weight based on the total amount introduced into the cooking system, and the temperature was raised. Started. At that time, the liquid ratio was adjusted to 2.5 LZkg with respect to the absolutely dry chips by combining the water content brought into the chips. 14 minutes after the start of heating When the temperature reached 0 ° C, 45% by volume of the whole digested black liquor was extracted from the autoclave. After extraction, 21.6% by weight of effective alkali in the digester is added to the second digestion liquor containing sodium hydroxide as the main component, which has been preheated to 90 ° C, and introduced into the digestion system. Was added so that the solution ratio became 2.5 L / kg. Further, at 240 minutes after the start of the cooking, a liquid having the same composition as the second cooking liquid having a sulfide degree of 30%, which was previously heated to 90 ° C, was added to the total amount introduced into the cooking system. 8.4% by weight of effective alkali. Table 9 shows the cooking results. According to this example, compared to Comparative Examples 12 to 15, the monovalent value of the pulp at the same effective alkali addition rate was reduced, and the pulp yield at the same effective porosity was increased.

 Example 23

The chips used for the digestion and the total effective alkali addition rate were the same as in Example 1, and the digester, the temperature and time of the digestion, the addition of the H-factor and the quinone compound were performed as in Example 19. The chips used for cooking and the total effective alkali addition rate were the same as in Example 1. The digester used an autoclave with a 2.5-L capacity that rotated upside down in an air bath in which an arbitrary temperature profile could be set. This device has a valve that can extract liquid in the autoclave and a valve that can inject liquid from outside into the autoclave. To explain the temperature profile of cooking, start cooking from room temperature, raise the temperature to 140 ° C in 30 minutes, then increase to 160 ° C in 60 minutes, and then increase the temperature to 160 ° C in 250 minutes. And cooked to an H-factor of 1 1400. At the start of the digestion, at room temperature, an alkaline solution containing sodium hydroxide and sodium sulfide as a main component was introduced into the electrolytic cell as a first digestion solution together with the chips, and sodium sulfide in the alkaline solution was electrolyzed. chemical oxidation-obtained Porisarufai Dosarufa concentration 1 O GZL (sulfur conversion calculation), hydroxide Natoriumu concentration _{70 g / L (N a 2} 0 equivalent) and sodium sulfide concentration 1 0. 6 g / L (N a 2 0 equivalent) alkaline cooking liquor of the main component, and added Caro to be 55 weight _^0/0 sulfur and 50% by weight of the active Al force Li with respect to the total quantity to be introduced into the cooking system, the Atsushi Nobori Started. At that time, the liquid ratio was adjusted to 2.5 L / kg with respect to the absolutely dry chips, in combination with the moisture brought in by the chips. When the temperature reached 140 ° C. in 30 minutes after the start of heating, 45% by volume of the whole digested black liquor was extracted from the autoclave. After the extraction, a second cooking liquor of 30% sulphide, which has been preheated to 90 ° C, is added to the digester with 31.6% by weight of an effective alkali in the digester. It was added so that the liquid ratio became 2.5 LZkg. Start cooking more When the temperature reached 240 minutes, a liquid having the same composition as the second cooking liquor having a sulfide degree of 30%, which had been preliminarily heated to 90 ° C, was added to the total amount introduced into the cooking system. 18.4% by weight. As the quinone compound, 1,4,4a, 9a-tetrahydroanthraquinone was mixed with the second cooking liquor in an amount of 0.05% by weight based on the dry chips. Table 10 shows the results of the cooking. According to this example, as compared with Comparative Examples 16 to 19, the pulp number at the same effective power addition rate was reduced, and the pulp yield at the same power value was increased.

 Example 2 4

 The chips used for the cooking, the total effective alkali addition rate were the same as in Example 1, and the cooking equipment, the cooking temperature, time, the H-factor and the addition of the quinone compound were the same as in Example 19, and The preparation and composition of the cooking liquor were performed in the same manner as in Example 23. At the start of the cooking, the first cooking liquor is added together with the chips at room temperature to a concentration of 74% by weight of sulfur and 70% by weight of the effective alkali with respect to the total amount introduced into the cooking system. Warm was started. At this time, the liquid ratio was adjusted to 2.5 L / kg with respect to the absolutely dry chips by combining the water brought in with the chips. When the temperature reached 140 ° C. in 30 minutes after the start of heating, 45% by volume of the whole digested black liquor was extracted from the autoclave. After the extraction, the second cooking liquor having a sulfidity of 30%, which had been heated to 90 ° C in advance, was digested with 21.6% by weight of an effective alkali based on the total amount introduced into the cooking system. The solution was added such that the liquid ratio in the solution became 2.5 LZ kg. Further, at 240 minutes after the start of the cooking, a liquid having the same composition as the second cooking liquid having a sulfuration degree of 30%, which had been heated to 90 ° C in advance, was introduced into the cooking system. 8.4% by weight based on the total amount of the effective alkali. Table 10 shows the cooking results. According to this example, as compared with Comparative Examples 16 to 19, the pulp value at the same effective alkali addition rate was reduced, and the pulp yield at the same effective pulp value was increased.

 Example 2 5

The chips used for the cooking, the total effective alkali addition rate were the same as in Example 1, and the cooking equipment, the cooking temperature, time, H_factor and the addition of the quinone compound were the same as in Example 19, and The preparation and composition of the cooking liquor were performed in the same manner as in Example 23. At the start of the cooking, the first cooking liquor is added together with the chips at room temperature so as to have a sulfur content of 100% by weight and an effective alkali content of 50% by weight based on the total amount introduced into the cooking system. Warm was started. That At this time, the liquid ratio was adjusted to 2.5 LZkg with respect to the absolutely dry chips by combining with the moisture brought in by the chips. When the temperature reached 140 ° C. in 30 minutes after the start of the temperature rise, 45% by volume of the whole digested black liquor was extracted from the autoclave. After extraction, a second cooking liquor containing sodium hydroxide as a main component, which has been preheated to 90 ° C, is treated with 31.6% by weight of effective alkali in the digester based on the total amount introduced into the cooking system. Was added so that the solution ratio became 2.5 LZkg. Further, at 240 minutes from the start of the cooking, a liquid having the same composition as the second cooking liquid having a sulfide degree of 30%, which was previously heated to 90 ° C, was added to the total amount introduced into the cooking system. Was added so as to be 18.4% by weight of effective alkali. Table 10 shows the results of the cooking. According to this example, as compared with Comparative Examples 16 to 19, the kappa monovalent at the same effective alkali addition rate was reduced, and the pulp yield at the same kappa monovalent was increased.

 Example 26

 The chips used for the digestion and the total effective alkali addition rate were the same as in Example 1, and the digester, the temperature and time of the digestion, the addition of the H-factor and the quinone compound were the same as in Example 19, and the first digestion was performed. The production method and composition of the liquid were the same as in Example 23. At the start of cooking, at room temperature, the first cooking liquor is added together with the chips so as to have a sulfur content of 100% by weight and an effective alkali of 70% by weight with respect to the total amount introduced into the cooking system. Started. At this time, the liquid ratio was adjusted to 2.5 LZkg with respect to the absolutely dry chips by combining the moisture brought in with the chips. When the temperature reached 140 ° C. in 30 minutes after the start of heating, 45% by volume of the whole digested black liquor was extracted from the autoclave. After the extraction, a second cooking liquor containing sodium hydroxide as a main component, which has been heated to 90 ° C in advance, is supplied with 21.6% by weight of an effective alkali with respect to the total amount introduced into the cooking system. Was added so that the solution ratio became 2.5 LZkg. Further, at 240 minutes from the start of the cooking, a liquid having the same composition as the second cooking liquid having a sulfide degree of 30%, which was previously heated to 90 ° C, was added to the total amount introduced into the cooking system. 8.4% by weight of effective alkali. Table 10 shows the results of the cooking. According to this example, as compared with Comparative Examples 12 to 15, kappa monovalent at the same effective alkali addition rate was reduced, and pulp yield at the same kappa monovalent was increased.

 Example 27

The chips used for cooking, total effective alkali addition rate, liquid ratio, amount of cooking black liquor extracted from the upper extraction strainer, temperature and time of the digester, addition of H-factor and quinone compound This was performed in the same manner as in Example 1. The first cooking liquor to be added at the top of the infiltration vessel was a polysulfide sulfur concentration of 4 g obtained by previously dissolving sulfur in an alkaline solution containing sodium hydroxide and sodium sulfide at 70 ° C. / L (terms of sulfur), an alkaline cooking liquor sodium hydroxide concentration 7 0 g / L (N a 2 0 equivalent) and sodium sulfide concentration _{30 g / L (N a 2} 0 equivalent) is the main component, the cooking system It was added so as to have a sulfur content of 56% by weight and an effective capacity of 50% by weight, based on the total amount introduced. At that time, the liquid ratio was adjusted to approximately 3.5 LZkg with respect to the absolutely dry chips, in combination with the moisture brought in by the chips. From the upper extraction strainer, 45% by volume of the total digested black liquor was extracted. In the upper cooking zone, a second cooking liquor of 30% sulphide was added to make 31.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. In the lower cooking zone, a liquid having the same composition as the second cooking liquor with 30% sulphide was added so as to be 18.4% by weight of effective alkali with respect to the total amount introduced into the cooking system. Table 12 shows the results of the digestion. According to this example, as compared with Comparative Examples 16 to 19, the kappa monovalent value at the same effective alkali addition rate was reduced, and the pulp yield at the same power value was increased.

 Example 2 8

The chips used for cooking, the total effective alkali addition rate, the liquid ratio, the amount of black liquor extracted from the upper extraction strainer, the temperature and time of the digester, the H-factor and the addition of the quinone compound were the same as in Example 1. I went. As the first cooking liquor to be added at the top of the permeation vessel, a polysulfide sulfur concentration obtained by previously dissolving sulfur in an alkaline solution containing sodium hydroxide and sodium sulfide as main components at 70 ° C. was used. GZL (sulfur conversion calculation), the total amount of the sodium concentration 70 GZL hydroxide (N a ₂ 〇 equivalent) and sodium sulfide concentration _{3 0 g / (N a 2} 0 equivalent) is introduced an alkaline cooking liquor of the main component in the cooking system To 100 wt.% Sulfur and 50 wt.% Effective alkali. The upper part cooking zone, sodium hydroxide the second cooking liquor of the main component, was added to a 3 1.6 wt _^0/0 effective alkali content of the total amount that will be introduced into the cooking system. In the lower cooking zone, a liquid having the same composition as the second cooking liquor containing sodium hydroxide as a main component was added so as to be 18.4% by weight of an effective alkali with respect to the total amount introduced into the cooking system. Table 12 shows the results of the cooking. According to this example, as compared with Comparative Examples 16 to 19, the pulp value at the same effective alkali addition rate was reduced, and the pulp yield at the same motive value was increased. o

 <Comparative example l>

 Chips used for cooking, total effective alkali addition rate, liquid ratio, method and composition of first cooking liquor

The temperature, time, H-factor and quinone compound of the digester were added in the same manner as in Example 1. The first cooking liquor added at the top of the infiltration vessel was added so as to have a sulfur content of 53% by weight and an effective alkali of 50% by weight based on the total amount introduced into the cooking system. From the upper extraction strainer, 15% by volume of the whole digested black liquor was extracted. At the bottom of the upper cooking zone, a second cooking liquor of 30% sulphidity is added to the total amount introduced into the cooking system by 3%.

1.6% by weight of effective alkali was added. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquor with a sulfuration degree of 30% was added so as to provide an effective amount of 18.4% by weight based on the total amount introduced into the cooking system. . Table 3 shows the cooking results.

 <Comparative Example 2>

 Chips used for cooking, total effective alkali addition rate, liquor ratio, production method of first cooking liquor, composition, amount of cooking black liquor extracted from upper extraction strainer, digester temperature, time and H-fat Performed as in Example 1. The first cooking liquor added at the top of the infiltration vessel was added so as to have a sulfur content of 53% by weight and an effective energy of 50% by weight based on the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor with a degree of sulphidation of 3096 was added so as to be 31.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquid having a sulfuration degree of 30% was added so as to have an effective alkali content of 18.4% by weight based on the total amount introduced into the cooking system. The quinone compound was added without addition. Table 3 shows the cooking results.

 <Comparative Example 3>

Chips used for cooking, total effective alkali addition rate, liquid ratio, production method of first cooking liquor, composition, amount of cooking black liquor extracted from upper extraction strainer, temperature, time, H-factor and quinone compound of digester Was added in the same manner as in Example 1. The first cooking liquor, added at the top of the infiltration vessel, was added so as to be 82% by weight of sulfur and 80% by weight of effective alkali relative to the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor of 30% sulphide was added to make 16.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking wash zone, the same set as the second cooking liquor with 30% sulfur The resulting liquor was added to an effective alkali content of 3.4% by weight based on the total amount introduced into the digestion system. Table 3 shows the cooking results.

 <Comparative Example 4>

 Chips used for cooking, total effective alkali addition rate, liquor ratio, method of preparing first cooking liquor, composition, amount of black liquor extracted from upper extraction strainer, temperature, time, H-factor-1 and quinone of digester The compound was added in the same manner as in Example 1. The first cooking liquor, which was added at the top of the osmotic vessel, was added so as to have a sulfur content of 32% by weight and an effective energy of 30% by weight based on the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor of 30% sulphide was added so as to be 41.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as that of the second cooking liquid having a sulfuration degree of 30% was added so as to have an effective alkali content of 28.4% by weight based on the total amount introduced into the cooking system. Table 3 shows the cooking results.

 <Comparative Example 5>

 The chips used for cooking, total effective alkali addition rate, liquid ratio, digester temperature, time, addition of H-factor and quinone compound were the same as in Example 9, and the preparation and composition of the first cooking liquor were carried out. Performed as in Example 1. The first cooking liquor, added at the top of the permeation vessel, was added so as to have a sulfur content of 53% by weight and an effective alkali of 50% by weight, based on the total amount introduced into the cooking system. From the upper extraction strainer, 15% by volume of the whole digested black liquor was extracted. At the bottom of the upper cooking zone, a second cooking liquor of 30% sulphide was added to make 31.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquor of 30% sulphide was added so that it became 18.4% by weight of effective alkali with respect to the total amount introduced into the cooking system. did. Table 5 shows the cooking results.

 <Comparative Example 6>

The chips used for the digestion, the total effective alkali addition rate, the liquor ratio, the amount of the digested black liquor extracted from the upper extraction strainer, the temperature and time of the digester, and the H-factor were the same as in Example 9, except for the first digestion. The production method and composition of the liquid were the same as in Example 1. The first cooking liquor, which was added at the top of the permeation vessel, was added so as to have a sulfur content of 53% by weight and an effective energy of 50% by weight based on the total amount introduced into the cooking system. 30% sulphide at the bottom of the upper cooking zone Of the second cooking liquor was added so as to be 31.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquor having a sulfuration degree of 30% was added so as to have an effective alkali content of 18.4% by weight based on the total amount introduced into the cooking system. The quinone compound was added without addition. Table 5 shows the cooking results.

 <Comparative Example 7>

 The chips used for cooking, the total effective alkali addition rate, the liquid ratio, the amount of black liquor extracted from the upper extraction strainer, the temperature and time of the digester, the addition of the H-factor and the quinone compound were the same as in Example 9, The production method and composition of the first cooking liquor were performed in the same manner as in Example 1. The first cooking liquor, which was added at the top of the infiltration vessel, was added so as to have a sulfur content of 82% by weight and an effective energy of 80% by weight based on the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor having a sulfuration degree of 30% was added so as to be 16.6% by weight of an effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquor having a sulfuration degree of 30% was added so that an effective amount of 3.4% by weight based on the total amount introduced into the cooking system was added. . Table 5 shows the cooking results.

 <Comparative Example 8>

 The chips used for cooking, the total effective alkali addition rate, the liquid ratio, the amount of black liquor extracted from the upper extraction strainer, the temperature and time of the digester, the addition of the H-factor and the quinone compound were the same as in Example 9, The production method and composition of the first cooking liquor were performed in the same manner as in Example 1. The first cooking liquor added at the top of the infiltration vessel was added so as to be 32% by weight sulfur and 30% by weight effective alkali relative to the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor having a sulfuration degree of 30% was added so as to be 41.6% by weight of an effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquor of 30% sulphide was added so as to have an effective amount of 28.4% by weight based on the total amount introduced into the cooking system. . Table 5 shows the cooking results.

 <Comparative Example 9>

The chips used for cooking, the total effective alkali addition rate, the liquid ratio, the method for preparing the first cooking liquor, the composition, the temperature, time and H-factor of the digester were the same as in Example 1, and the quinone compound was added. The procedure was performed in the same manner as in Example 11. The first cooking liquor, added at the top of the infiltration vessel, contained 53% by weight of sulfur and 50% by weight of active I made it into potash. From the upper extraction strainer, 15% by volume of the total digested black liquor was extracted. At the bottom of the upper cooking zone, a second cooking liquor with 30% sulphide was added to make 21.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquor having a sulfidity of 30% was added so as to be 8.4% by weight of the effective alkali with respect to the total amount introduced into the cooking system. Table 8 shows the cooking results.

<Comparative Example 10>

 The chips used for cooking, the total effective alkali addition rate, the liquid ratio, the method for preparing the first cooking liquor, the composition, the temperature, time and H-factor of the digester were the same as in Example 1, and the quinone compound was added. The procedure was performed in the same manner as in Example 11. The first cooking liquor, added at the top of the infiltration vessel, was added so as to have a sulfur content of 82% by weight and an effective alkalinity of 80% by weight, based on the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor with a sulfuration degree of 30% was added so as to be 16.6% by weight of an effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the cooking washing zone, a liquid having the same composition as the second cooking liquid having a sulfuration degree of 30% was added so as to have an effective alkali content of 3.4% by weight based on the total amount introduced into the cooking system. Table 8 shows the cooking results.

 <Comparative Example 1 1>

 The chips used for cooking, the total effective alkali addition rate, the liquid ratio, the method for preparing the first cooking liquor, the composition, the temperature, time and H-factor of the digester were the same as in Example 1, and the quinone compound was added. The procedure was performed in the same manner as in Example 11. The first cooking liquor, which was added at the top of the permeation vessel, was added so as to have a sulfur content of 32% by weight and an effective alkali of 30% by weight based on the total amount introduced into the cooking system. At the bottom of the upper cooking zone, a second cooking liquor of 30% sulphide was added so as to be 41.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. At the bottom of the digestion washing zone, a liquid having the same composition as the second cooking liquor having a degree of sulfuration of 30% was added so as to have an effective alkali content of 28.4% by weight based on the total amount introduced into the digestion system. Table 8 shows the cooking results.

 <Comparative Example 1 2>

The chips used for cooking, the total effective alkali addition rate were as in Example 1, using the digester, the method for preparing the first cooking liquor, the composition, the cooking temperature, the time, the H-factor and the quinone compounds. The addition was performed in the same manner as in Example 19. At the start of cooking, the first cooking liquor was added together with chips at room temperature so that the sulfur content was 53% by weight and the effective alkali was 50% by weight based on the total amount introduced into the cooking system, and the temperature was raised. did. At that time, the liquid ratio was adjusted to 2.5 L kg with respect to the absolutely dry chips, together with the moisture brought in by the chips. When the temperature reached 140 at 30 minutes after the start of heating, 45% by volume of the whole digested black liquor was extracted from the autoclave. After the extraction, the second cooking liquor of 30% sulphide, which has been preheated to 90 ° C, is treated with 31.6% by weight of effective alkali in the digester based on the total amount introduced into the cooking system. Was added so that the solution ratio became 2.5 LZkg. Further, at 240 minutes from the start of the cooking, a liquid having the same composition as the second cooking liquid having a sulfuration degree of 30%, which had been heated to 90 ° C in advance, was used for the total amount introduced into the cooking system. 18.4% by weight of effective alkali. The cooking results are shown in Table 11

<Comparative Example 13>

 The chips used for cooking and the total effective alkali addition rate were the same as in Example 1, except for the digester,

The preparation method, composition, cooking temperature, time, and H-factor of the cooking liquor of 1 were performed in the same manner as in Example 19. At the start of cooking, the first cooking liquor was added together with the chips at room temperature so that the sulfur content was 53% by weight and the effective alkali was 50% by weight based on the total amount introduced into the cooking system, and the temperature was raised. did. At that time, the liquid ratio was adjusted to 2.5 LZkg with respect to the absolutely dry chips by combining with the moisture brought in by the chips. When the temperature reached 140 ° C. in 30 minutes after the start of heating, 45% by volume of the whole digested black liquor was extracted from the autoclave. After extraction, a second cooking liquor of 30% sulphide, previously heated to 90 ° C, is heated to 31.6% by weight of the effective alkali in the digester with respect to the total amount introduced into the cooking system. It was added so that the ratio became 2.5 L / kg. Further, at 240 minutes after the start of the digestion, the sulphide with a sulfuration degree of 30%, which had been heated to 90 ° C in advance, was used.

A liquid having the same composition as the cooking liquor of No. 2 was added so as to be 18.4% by weight of an effective alkali with respect to the total amount introduced into the cooking system. The quinone compound was added without addition. Table 1 shows the cooking results

Shown in 1.

 Comparative Example 14>

The chips used for the cooking and the total effective alkali addition rate were the same as in Example 1, except that the cooking equipment, the method for preparing the first cooking liquor, the composition, the cooking temperature and time, the addition of the H-factor and the quinone compound were implemented. The procedure was as in Example 19. At the beginning of the digestion, at room temperature, with the chips, The cooking liquor was added so as to have a sulfur content of 83% by weight and an effective alkali of 80% by weight based on the total amount introduced into the cooking system, and the temperature was raised. At that time, the liquid ratio was adjusted to 2.5 LZkg with respect to the absolutely dry chips by combining the moisture brought in with the chips. When the temperature reached 140 ° C. in 30 minutes after the start of the temperature rise, 15% by volume of the whole digested black liquor was extracted from the autoclave. After the extraction, a second cooking liquor of 30% sulphide, previously heated to 90 ° C, is heated to 16.6% by weight of the effective alkali in the digester with respect to the total amount introduced into the digestion system. It was added so that the ratio became 2.5 LZkg. Further, at 240 minutes from the start of the cooking, a liquid having the same composition as the second cooking liquid having a sulfide degree of 30%, which was previously heated to 90 ° C, was added to the total amount introduced into the cooking system. 3. 4% by weight of effective alkali was added. Table 11 shows the results of the cooking. <Comparative Example 15>

 The chips used for the cooking and the total effective alkali addition rate were the same as in Example 1, and the cooking equipment, the preparation method of the first cooking liquor, the composition, the cooking temperature and time, the addition of the H-factor and the quinone compound were the same as in Example 1. Performed in a similar manner to 19. At the start of cooking, the first cooking liquor was added together with the chips at room temperature so that the sulfur content was 32% by weight and the effective alkali was 30% by weight based on the total amount introduced into the cooking system, and the temperature was raised. did. At that time, the liquid ratio was adjusted to 2. S LZkg for the absolutely dry chips by combining the moisture brought in with the chips. When the temperature reached 140 ° C. in 30 minutes after the start of the temperature rise, 15% by volume of the whole digested black liquor was extracted from the autoclave. After the extraction, a second cooking liquor containing sodium hydroxide as a main component, which has been heated to 90 ° C in advance, is supplied with 41.6% by weight of an effective alkali based on the total amount introduced into the cooking system. The solution was added such that the liquid ratio in the solution became 2.51 / kg. Further, at 240 minutes from the start of the cooking, a liquid having the same composition as the second cooking liquid having a sulfide degree of 30%, which had been heated to 90 ° C in advance, was added to the total amount introduced into the cooking system. 28.4% by weight of effective alkali was added. Table 11 shows the results of the cooking.

 <Comparative Example 16>

The chips used for cooking, total effective alkali addition rate, liquid ratio, digester temperature, time, H-factor and addition of quinone compound were the same as in Example 1, and the production method and composition of the first cooking liquid were the same as in Example 1. Performed similarly to 27. The first cooking liquor added at the top of the permeation vessel was such that 56% by weight of sulfur and 50% by weight of available alkali were based on the total amount introduced into the cooking system. From the upper extraction strainer, 15% by volume of the total Extracted. In the upper cooking zone, a second cooking liquor with a sulphidity of 30% was added to make up 21.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. In the lower cooking zone, a liquid having the same composition as the second cooking liquor having a sulfidity of 30% was added so as to be 8.4% by weight of an effective alkali with respect to the total amount introduced into the cooking system. Table 13 shows the results of the cooking.

<Comparative Example 17>

The chips, total effective alkali addition rate, liquid ratio, digester temperature, time and H-factor used in the cooking were the same as in Example 1, and the production method and composition of the first cooking liquor were the same as in Example 27. I went. The first cooking liquor added at the top of the permeation vessel was added so as to have a sulfur content of 56% by weight and an effective energy of 50% by weight based on the total amount introduced into the cooking system. In the upper cooking zone, a second cooking liquor with a sulphidity of 30% was added so as to be 11.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. A liquid having the same composition as the second cooking liquor sulfidity 3 0% in the lower cooking zone, was added 8.4 wt _0/0 becomes effective alkali content of such relative to the total amount introduced into the digester system. The quinone compound was added without addition. Table 13 shows the results of the digestion.

 <Comparative Example 18>

 The chips used for cooking, total effective alkali addition rate, liquid ratio, digester temperature, time, H-factor and quinone compound addition were the same as in Example 1, and the method and composition of the first cooking liquor were the same as in Example 1. Performed similarly to 27. The first cooking liquor, added at the top of the permeation vessel, was added so as to have a sulfur content of 83% by weight and an effective alkali content of 80% by weight, based on the total amount introduced into the cooking system. In the upper cooking zone, a second cooking liquor with a sulphidity of 30% was added to make up 16.6% by weight of effective alkali with respect to the total amount introduced into the cooking system. In the lower cooking zone, a liquid having the same composition as the second cooking liquor having a sulfidity of 30% was added so as to have an effective alkali content of 3.4% by weight based on the total amount introduced into the cooking system. Table of cooking results

See Figure 13.

 <Comparative Example 19>

The chips used for cooking, total effective alkali addition rate, liquid ratio, digester temperature, time, H-factor and quinone compound addition were the same as in Example 1, and the method and composition of the first cooking liquor were the same as in Example 1. Performed similarly to 27. The first cooking liquor, which is added at the top of the infiltration vessel, contains 46% by weight of sulfur and 30% by weight of active It was added so as to become potash. The second cooking liquor sulfidity 3 0% in the upper cooking zone, was added 4 of. 6 weight _^0/0 becomes effective alkali of such relative to the total amount to be introduced into the vapor solution system. In the lower cooking zone, a liquid having the same composition as the second cooking liquor having a sulfidity of 30% was added so as to have an effective alkali content of 28.4% by weight based on the total amount introduced into the cooking system. Table 13 shows the cooking results.

L Example, seepage vessel

Table 1 Examples of actual artillery, ratio! ^ NO. 1 Difficult 1 Example 2 雞 Implementation «4

 Wood chips Hardwood mixed material I Hardwood mixed material Wide green tree mixed material Wide mixed material Total effective alkali addition rate (vs. dry copper 7F 'overlap) (: as Na20) 11.9 12.8 13.6 1 11.9 12.8 13.6 11.9 12.8 13.6 11.9 12.8 13.6 Addition, extraction bottle place L

 Al or J-soluble steam Polysulfide concentration in IB liquid (g / i) 4 4 4 4 Steam) Effective Al or J split ratio (heavy) for all i introduced into the system 50 70 50 70

(3) 8.9 9.5 & 8 8.3 8.9 9.5 硗 yellow splitting ratio for all units introduced into cooking system (multiple units) 53 1G0 100

16 quinone compound .4a9a-te 'Q ank / one 1.¼-ed Q anthrax U4a9a> f de B ank /: / I.4.4a9a- 亍 Anquinone compound addition ratio (vs. weight x) 0.03 0.03 0.03 0.03 Upper extraction 4 Extraction H ratio to total steamed black liquor (to total black liquid) 0 45 45 45 45

 Effective Al splitting ratio for all components in the system (weight w 31.6 21.6 31.6 21.6

8 Effective aluminum addition rate (dry weight) 3.8 4.0 4.3 2.5 2.7 2.9 3.B 4.0 4.3 2.6 2.8 2.9

 硗 degree (<< 30 30 0 0

16 'Quinone compound

 Quinone fc compound addition rate (vs.

 Shimoide Sode 6 Extraction ratio to total digested black liquor (total black liquor ϋ) 55 55 1 55 55

 Effective al addition to the total amount introduced into the steam system iltt (in) 18.4 β.4 18.4 8.4

9 Effective Al or J addition rate (vs. ί and dry weight of 'Noff') 2.2 2.3 2.5 '0 1.1 1.1 2.2 2.3 2.5 1.0 1.1 1.1

 Degree of aging («30 30 30 0

H-factor 830 830 1 830 830 Valve yield W `` 5 54.5 53.6 55.7 54.3 54.0 55.0 54.2 53.5 55.0 54.4 53.4 Birch or Zipa -ffi 22.1 17.5 15.8 23.0 ia.o 16.5! 9.7 15.7 15.0 20.7 16.2 15.3

KANOVA Valve yield in HB18 (W 54.5 54.4 54.6 54.6

Table 2

 L Example, Penetration

 Actual W-ratio O. 1 I mm 1 Example 7 mm wood chip 1 Hardwood mixed Hardwood mixed material 1 Broadwood mixed material Hardwood mixed material Total effective alkali addition rate (vs. absolute I: S: as Na20) |! 1.9 128 13.6 11.9 12.8 13.6 S 11.9 12.8 13.6 11.9 12.8 13.6 iS Addition location 1 1

 Al; W polysulfite degree in cooking liquor (g i) 10 to 10 10 Effective SI addition ratio to total SI input to cooking system (overlapping X) 50 70 50 70

3 Effective al: b'J¾ft rate (¾¾¾ tiff 'overlap W 6.0 & 8 ί.3 8.9 9.5 6.0 & 4 6.8 8.3 8.9 9.5 To digestion system に 対 す る!

1.4. 9a-テラ t Dアントラキ M.4a9a- tド Dアントラキ キノン匕合物添加率 (対 乾チ7フ'重量 ϋ) 1 0.03 0.03 0.03 上部抽出 4 全囍黒液に対する抽出黒液比率 (対全黒液体 Χ) 45 1 45 45 45 16 quinonation stand IA4a9a-te 07

1.4. 9a-Tera t-D anthraquin M.4a9a-t-D D-anthraquinone conjugate compound addition rate (vs. dry weight) 1 0.03 0.03 0.03 Upper extraction 4 Ratio of black liquor to total black liquor (vs. All black liquid Χ) 45 1 45 45 45

 Steam! ! To the system 全 all il: effective al or J division ratio (heavy) 31.6 1 21.6 31.6 21.6

 8 Effective alkali addition rate (vs. dry weight) X 4.0 3.8 4.3 1 26 2.8 2.9 3.8 4.0 4.3 2.6 2.8 2.9 硗 fe degree (X) 30 1 30 0 0

 16 'g compound

 Quinone 1 conjugate addition vs. 7 'heavy

 Lower extraction 6 Ratio of spiked black liquor to total digested black liquor (vs. total black liquor rest ^ 55 [55 55 55

 Effective fraction of the total amount introduced into the steam system or J-division ratio (heavy) 18.4 M 1B.4 8.4

 9 Effective Al or Jljo rate (vs. dry weight n) 22 2.3 2.5 1 1.0 1.1 t.l 2.2 2.3 2.5 1.0 1.1

 Degree of contact (<< 30 1 30 0 0

H-Factor 830 I 630 630 830 Pulp yield (W 55.6 54.8 54.0 1 56.2 55.2 54.8 56.1 55.2 54.4 56.2 55.0 53.8 Steam result / Par value 18.4 16.4 15.4 1 19.5 16.8 16.1 18.5 16.0 15.0 16.2 15.5 U.6 Kappa 18 Pulp in «Rate (X) 55.6 1 55.7 56.0 I 56.1

Table 3

Table 4

 N Example, seepage vessel

 Actual / Comparative NO. 1 Difficult Real 10 Wood chip 1 Needle material Needle piercing material Total effective alkali addition rate (relative to absolute dry weight 1: Na20) 14.5 16.5 18.5 14.5 16.5 18.5

Addition and extraction location

 Polysulphide g-degree (g / l) in a liquor steam 10 Effective ratio for all children entering the digestion system

3 Effective Al: ^ Addition rate (per weight x) 7.3 8.3 9.3 7.3 8.3 9.3 Cooking 硗 Yellow splitting ratio (weight) for all ft introduced to 0 0 53 1 100

16 Quinone compound U 9a-Ted 137 Ntraquinone

 K / N compound addition rate (vs. dry chief IlW 0.05 0.05 Upper sleeve 24 Extraction S ratio to total black liquor (vs. total black liquor ¾Χ) 45 45

 Steam) The effective al or J split ratio for all I poisoned (? 31.6 31.6

8 Effective alkali rate (vs. absolute dry weight x) 4.6 5.2 5.B 4.6 5.2 5.8

 30 0

! 6 'Quinone compound

 Quinone compound addition rate

 Lower extraction 26 Ratio of black soybean liquor to total black liquor (total black liquor) 0 55 55

 All fi to be introduced into the steaming system: effective alka or J split ratio (weight << 18.4 18.4

9 Effective Alkali rate (vs. ft dry chip 7 X amount) 2.7 3.0 3.4 3.0 3.4

 Degree of degradation () 30 0

H-factor-1) 400 1400 Pulp yield (X) Γ 46.4 45.5 45.0 47.5 46.4 45.7 Digestion result Cutler value 26.2 22.3 20.2 26.B 22.0 19.3

Valve yield at Kappa ΗΪ25 (X) 46.2 47.1

Table 5 Example N, seepage vessel

 Example 'Comparative Example NO.B Ratio 较 Example 5 m Ratio ^ 7 Ratio Tree ίίChip Note Mixing Material Rising Mixing Material Needle Leaf Material Harbour Tree Mixing Material All Effective Al or J Addition Rate (Na20) 45 16.5 18.5 14.5 1 16.5 18.5 14.5 1 16.5 16.5! 4.5 16.5 18.5 Addition

 Alka J-steam βϊ $ polysulfide concentration (g / l) 4 4 4 4 Effective al. J] re-split ratio (w / stt 50 50 80 30)

3 Effective Al or J addition rate (vs. dry weight)! ) 7.3 8.3 S3 7.3 8.3 9.3 11.6 13.2 14.8 4.4 5.0 5.6 Splitting ratio of yellowing to all i introduced into the digester (heavy) 53 53 62 32

16 Quinone compound U.Wa- La D Anthraquinone U4¾-i-Tra!: Droanthraquinone 1.4.4a9a-i tKO anth / quinone compound] »Rate (vs ft dry weight 0.05 0 0.05 0.05 Top extraction 24 All black Ratio of extracted black liquor to liquid $ (to total black liquor ridge W 15 45 45 45

 Effective Al / J Split Ratio (Weight) 全) 31.6 31.6 16.6 41.6

8 Effective Alkali or J Addition Rate (Port x 7 x Weight x) 4.6 5.2 5.6 4.6 5.2 5.8 2.7 3 + 1 6.0 6.9 7.7 Degree of Degree (X) 30 30 30 30

16 'Quinone compound

 Quinone compound addition rate (vs. absolute dry weight W

 Lower extraction 26 Ratio of pumping liquid to total black liquor (to total black liquor ridge X) 85 55 55 55

 Effective Al splitting ratio to total S input to cooking system (weight X) 18.4 1B.4 3.4 28.4

9 Effective Al; W addition ratio (vs. weight) 2.7 3.0 3.4 2.7 3.0 3.4 0.5 0.6 0.6 4.1.7 5.3

 Degree of oxidation (X) 30 30 30 30

H-factor "00 1400 1400 1400 Valve yield (W 1 47.1 46.0 45.2 47.1 1 46.1 45.0 46.7 46.0 45.2 46.8 46.3 45.2 Digestion result Kappa Hi I 34.0 27.8 23.3 38.0 30.7 24.8 31.3 27.! 23.0 35.0 30.2 24.3 At Kappa 25 Valve yield (WR 45.0 1 45.1 R 4S.2 45.3

L Example, upper cooking zone

Table 6 Example 6 Example No. Example 1 Example 12 Example 13 Example 14

 Wood Chips Hardwood Mixtures I Hardwood Mixtures Hardwood Mixtures Hardwood Mixtures All Available Al :)] Re-addition Rate (vs. FT Dried "" Heavy i! I; as Na20) 11.9 12B 13.6 | 11.9 12.8 13.6 11.9 12.8 13.6 11.9 12.8 13.6

 -"

 Addition and extraction location

 Al: ^ polysulfide in the cooking liquor; sales degree (g / l) 4 4 4 4 Effective Al to total amount introduced into the digestion system or J split ratio (weight X) 50 70 50 70

3 Effective Al addition rate (vs. absolute dry chip 'Weight X) 6.0 & 4 6.8 8.3 6.9 9.5 6.0 & 4 & 8 8.3 8.9 9.5 Yellow splitting ratio (Weight) 1) 53 72 100 100

16 Quinone compounds

 匕 匕 加 対 対 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

 Effective amount for the total amount introduced into the system; W division ratio (cylinder amount) 31.6 21.6 31.6 ― 21.6

8 Effective Al or J addition rate (vs. 7 'X) 3.8 4.0 4.3 16 2.8 2.9 3.8 4.0 4.3 2.6 2.8 2.9

00 Degree of hydrophobicity () 30 30 0 0

16 'Quino compounds 1.4.¼9a "卄 Rahid D anthraquin 1, Ma9a-i D D anthraquin / n ¹ U4a9a- † Trahiid 07'No thraquin / n U¼9a-tetra t` `D Anthran quinone compound addition rate (vs. Weight! 0 0.03 0.03 0.03 0.03 Lower extraction 6 Extraction ratio to total vapor (to total black liquid U) 1 55 55 55 55

 I Alkali splitting ratio to the total amount introduced into I solution system (sign fci) 18.4 18.4 8.4

9 Effective alkali addition rate (vs. ¾n tiga weight) 2.2 2.3 2.5 1.0 1.1 1.1 11 2.3 2.5 1.0 1.1 Sulfidation degree (W 30 30 0 0

H-factor-800 800 800 800 Valve yield (X) 54.7 54.3 53.4 54.7 54.2 53.5 55.0 54.2 53.7 54.6 54.2 53.4 Digestion result Copper collision 22.6 19.0 16.1 23.1 19.5 16.7 21.9 18.8 15.7 ?? 1 19.0 16.3 Yield (X) 540 53.6 54.1 53.9

Table 7

Table 9

Table 10

Table 11 1 L Examples, Laboratory Cooking, Infiltration Vessel

 Comparison «12 1 Comparative Example 13 比較 Comparative Example 14 Comparative β Example 15 Tao W Broadleaf Mix 1 Broad Broad Mixer Broad Confectionery Mixed Broadleaf Broadleaf Wood All / Ri ^ JO Dro (对 ffi¾" F ISS: as Na20) 11.9 12.8 13.6 11.9 12.8 13.6 11.9 12.8 13.6 11.9 12.8 13.6

* Extraction location

 ι1

 Alkaline tt liquid τρ resulfite << Sig / l) 4 4 4

 専 河 9 Ή 幼 刀 リ ΛΙ ΛΙ ΛΙ ΛΙ ΛΙ iW 50 50 80 30

 J Yo / Le sword; half フ 6.0ν 6.0 6.4 6.4 & 8 9.5 10.2 10.9 3.6 3.8 4.1 All il to be put into the digester: yellowing ratio to yellow (weight) 53 53 82 32

I D T / ノ ¾l

 0 0 0 0 0 Upper extraction 4 Extraction S solution ratio to total digestion black liquor (total black S rest 8) 15 45 45 45

 ft to Λό ^ wang ffi 、】 9 ¾> fl¾J / le W ri ^ iffjm ri 31.6 31.6 16.6 41.6

 3.8 4.0 4.3 3.6 4.0 4.3 2.0 2.1 2.3 5.0 5.3 5.7 硗 化 () 30 30 30 30

Ι6 '// ン compound 1.4.4ϊ -D DD7 ン / ン U¼9a-tetrahine 7 7raki Ufe9a-i tt α-anthraquinone compound addition rate (vs. absolute dry weight x) 0.03 0.03 0.03 0.03 Lower extraction 6 All Extracted black liquor to digested black liquor ratio (to total black liquor «S5 55 55 55

 Effective amount based on the total amount introduced into the steam system; Permeation ratio (weight) 1) 18.4 18.4 3.4 2 3.4.4

9 Effective Alkali J addition rate Dry f Weight W 2.2 2.3 2.5 2.2 2.3 2.5 0.4 0.4 0.5 3.4 3.6 3.9 Degree of W 30 30 30 30

H-factor BOO eoo 800 800 Pulp yield (X) 54.4 53.8 53.0 [54.3 53.7 52.8 54.6 53.8 52.9 53.9 53.4 52.6 Digested fruit or ffi 24.5 21.0 Ι6.β 25.0 21.4 17.3 25.1 21.4 17.5 25.9 22.0 17.8 Pulp yield («53.2 52.9 53.0 52.7

Table 12

Kindness

Table 13 Example · Comparative Example O. Comparative Example 16 Comparative «117 1 较 Comparative 较« 119

 Wood chips HIROKI difficult mixture I HIROSHI mixture 1 HIROKI SHIMI mixture 1 ΰ; Foliage mixture Total effective alkali addition rate (vs. Zi-ku Chikufu's heavy iX: as Na20) 11.9 12.6, 3.6 I 11.9 12 β 13.6 H 11.9 12.8 13.6 1 11.9 12.8 13.6 Addition, extraction well 1

 Al or J Polysulphide compliance in cooking liquor (g / l) 4 4 4 4 Effective al to total amount introduced into the digestion system; /] Refractionation ratio (Heavy ix) 50 50 BO 30

3 Effective Alkali Addition Ratio (vs. Tiger Weight X) 6.0 6.4 6.0 6.4 & 8 9.5 10.2 10.9 3.6 3.8 4.1 Yellow Split Ratio to Total Amount Introduced to Cooking System (Heavy ix) 56 56 β3 46

16 Quinone compounds

 Quinone fc compound addition rate (vs. ft dry chip weight) 0 0 0 0 Upper extraction 4 Full steam) !? Extracted black liquor to black liquor ratio (total)! Liquid contact 0 15 1 45 45 45

 Effective fraction of total λ to be introduced into the steam system or J split ratio (weight X) 31.6 31.6 16.6 41.6 β Effective fraction of additive weight W 3.8 4.0 4.3 3.8 4.0 4.3 I 2.0 2.1 2.3 5.0 5.3 5.7 Sulfidation degree (W 30 30 30 30

16 'Quinone compound

 Quinone compound addition rate (to ft dry chip liW 0.03 0 O.03 0.03 Lower extraction 6 Ratio of extracted black liquor to total steamed i liquor (total black liquor 8X) 85 55 1 55 55

 Total il to be digested to the cooking system: ratio of effective al addition to total il (multiple 重) 18.4 18.4 3.4 28.4

9 Effective alkali addition rate (vs. weight iW 2.2 2.3 2.5 2.2 2.3 2.5 0.4 0.4 0.5 3.4 3.6 3.9 Sulfidation degree (X) 30 30 30 30

H-factor-1 800 800 800 800 Pulp yield (X) I 54. 53.5 52.7 53.9 53.4 52.6 54.2 53.7 52.8 54.0 53.2 52.3 Digestion result Cutlet value 27.0 21.0 17.1 26.2 21.9 17.0 25.6 21.6 I6.S 28.0 22.5 17.3 Kappa-pulp yield at IS18 (X) 52.9 52.7 53.0 52.4

Industrial applicability

 According to the present invention, the pulp yield can be further improved, and the relationship between kappa monovalent and pulp yield can be further improved. That is, the present invention can reduce the kappa value at the same effective alkali addition rate and can improve the pulp yield at the same strength of the brim.

Claims

The scope of the claims 1. A two-vessel digester in which an infiltration vessel is installed in front of a digester, which has a top zone, an upper digestion zone, and a lower digestion zone inside the digester from top to bottom. A strainer is provided at the bottom of the zone, and at least one of the strainers is used to discharge the black liquor extracted from one of the strainers to the outside of the digestion system.2 In continuous cooking using a vessel digester, hardwood or softwood Containing 3 to 20 g / L of sulfur as sulfur, and reducing total digestion-active sulfur and total alcohol contained in the alkaline cooking liquor introduced into the digestion system. 4 5 to 1 0 0 wt _^0/0 of the digester active sulfur and 4 for 5-7 9 wt% alkaline soluble cooking liquor comprising an effective Al force Li of added penetration vessel top against further bone dry chips Per 0.0 1-1. A method for cooking lignocellulosic material, comprising feeding an alkaline cooking liquor containing 5% by weight of a quinone compound to an osmotic vessel or to the bottom of said upper cooking zone.  2. The sulfuric acid obtained by electrochemically oxidizing sodium sulfide in the alkaline cooking solution containing sodium hydroxide and sodium sulfide or sodium carbonate and sodium sulfide as main components. 2. The method for cooking a lignocellulosic material according to claim 1, wherein the cooking liquid is an alkaline cooking liquid containing 3 to 20 g ZL of polysulfide sulfur. 3. In the continuous digestion method using the 2-vessel digester described above, at least the digested black liquor discharged to the outside of the digestion system is extracted from the strainer at the bottom of the tower top zone, and sent to the recovery process directly from the digester. steamed solution of lignocellulosic material according to claim 1 or 2 2 0-6 0 volume _^0/0 cooking black liquor is characterized in that it is extracted with scan trainer of top zone bottom.  4. The method for digesting lignocellulosic material according to any one of claims 1 to 3, wherein a digestion washing zone is further provided below the lower digestion zone.  5. The digestion method for a lignocellulose material according to any one of claims 1 to 4, wherein the alkaline cooking liquor containing 0.02 to 0.06% by weight of a quinone compound per absolutely dry chip is filled with the permeation vessel. Cooking a lignocellulosic material, wherein the lignocellulosic material is fed to the top or bottom of an upper cooking zone. 6. Polysulfuride in alkaline cooking liquor added at the top of the infiltration vessel The method for cooking a lignocellulosic material according to any one of claims 1 to 5, wherein the concentration of rufa is 8 to 18 gZL as sulfur.