WO2016072919A1 - Procédé de fonctionnement d'un système de digesteur à deux cuves - Google Patents

Procédé de fonctionnement d'un système de digesteur à deux cuves Download PDF

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Publication number
WO2016072919A1
WO2016072919A1 PCT/SE2015/051161 SE2015051161W WO2016072919A1 WO 2016072919 A1 WO2016072919 A1 WO 2016072919A1 SE 2015051161 W SE2015051161 W SE 2015051161W WO 2016072919 A1 WO2016072919 A1 WO 2016072919A1
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WO
WIPO (PCT)
Prior art keywords
liquor
digester
cooking
vessel
impregnation
Prior art date
Application number
PCT/SE2015/051161
Other languages
English (en)
Inventor
Fredrik Wilgotson
Magnus Hägglund
Krister Olsson
Original Assignee
Valmet Ab
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Valmet Ab filed Critical Valmet Ab
Priority to BR112017009620-0A priority Critical patent/BR112017009620B1/pt
Priority to EP15857624.9A priority patent/EP3215672B1/fr
Publication of WO2016072919A1 publication Critical patent/WO2016072919A1/fr

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Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C11/00—Regeneration of pulp liquors or effluent waste waters
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C3/00—Pulping cellulose-containing materials
    • D21C3/02—Pulping cellulose-containing materials with inorganic bases or alkaline reacting compounds, e.g. sulfate processes
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C3/00—Pulping cellulose-containing materials
    • D21C3/22—Other features of pulping processes
    • D21C3/24—Continuous processes
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C9/00—After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
    • D21C9/02—Washing ; Displacing cooking or pulp-treating liquors contained in the pulp by fluids, e.g. wash water or other pulp-treating agents
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C11/00—Regeneration of pulp liquors or effluent waste waters
    • D21C11/0021—Introduction of various effluents, e.g. waste waters, into the pulping, recovery and regeneration cycle (closed-cycle)
    • D21C11/0028—Effluents derived from the washing or bleaching plants
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C7/00—Digesters
    • D21C7/14—Means for circulating the lye

Definitions

  • the present invention concerns a method for the continuous cooking of cellulose according to the introduction to claim 1 with the aim of achieving improved washing and delignification at less losses in heat economy.
  • FIG. 1 shows the development of continuous cooking processes with start from 1957;
  • FIG. 1 shows schematically the flow routing in Compact Cooking G2
  • Figure 3 show the upper part of the atmospheric impregnation vessel used in Compact Cooking G2;
  • FIG. 4 shows in further detail the liquor routing in Compact Cooking G2;.
  • Figure 5 show the improvement in Compact Cooking, using the atmospheric first vessel for recovering the increased flow of heated liquors to the digester system as steam for chip steaming;
  • Figure 6 shows a preferred brown wash in form of a pressure diffuser washing the pulp coming directly from the blow line of the digester.
  • Compact Cooking is more of an opposite to Lo-Solids cooking as the content of dissolved hemicellulose is kept high during the cook in order to increase yield as the hemicellulose starts to precipitate back on the pulp at final phases of cook.
  • Hemicelluose is a large part of the dissolved organic content, which in Lo-Solids cooking deliberately is kept low throughout the cook by multiple extractions of black liquor, and often the total organic content is kept below 100 g/l throughout the cook, which of course results in losses in yield.
  • the atmospheric impregnation vessel with substantial retention time, and a dedicated cooking vessel is the optimal design of the digester system.
  • the atmospheric impregnation vessel enable a thorough impregnation of comminuted cellulosic material with alkali all the way to the core of the comminuted cellulosic material, reducing the amount of rejects after cook to a minimum.
  • the comminuted cellulosic material are also steamed in the very same vessel by adding hot black liquor to the liquor level established in the ImpBin, allowing steam to flash off and into an established chip volume above liquor level.
  • the patent US71 12256 is related to the CrossCirc features that the bulk volume of return liquor from the top separator is instead sent to this liquor level in ImpBin, and before that is instead hot black liquor added to start of transfer (instead of the top separator return liquor that was conventional practice). This improves heat economy as heating takes place towards cooking temperature in transfer to digester, and the residual heat in the top separator return liquor is allowed to flash off for steaming, while yet establishing a low impregnation temperature in black liquor after flashing.
  • the concepts with Compact Cooking G2, using an ImpBin is disclosed also in
  • FIG. 2 A more detailed process flow chart of a Compact Cooking G2, using an ImpBin and CrossCirc is shown in figure 2.
  • the digester is simplified with only 2 screen sections, and in the first upper screen section is hot black liquor HBLi withdrawn at full cooking temperature. This HBLi is added to end of ImpBin and at start of transfer of the comminuted cellulosic material to raise the temperature in feed line TSFEED to top separator according to CrossCirc practice.
  • the main charge of alkali to the digester is at the very top of the digester, so there will be a considerable residual alkali level in the HBLi liquor, as this residual alkali level must be sufficient to maintain the residual alkali level at end of next cooking zone above 6 g/l (avoiding lignin condensation etc).
  • the return liquor TSRET withdrawn in top separator i.e. the transport fluid in TSFEED,.
  • the TS alkali residual and temperature is a mixture of the temperature and alkali in the end of the impregnation plus the addition of HBL1 which main purpose is to increase the temperature of the TS.
  • steaming comminuted cellulosic material being fed at ambient temperature directly to ImpBin requires quite different amount of steam if the comminuted cellulosic material are fed from an outside chip pile at ambient temperatures of -30 to -40°C, compared to feeding comminuted cellulosic material from an outside chip pile at ambient temperatures of +30 to +40°C.
  • the further heating is only done in cold seasons while no further heating is done in warm seasons.
  • the heating effect of the hot black liquor is first used to elevate the temperature in transfer towards cooking temperature without any heat losses, and the residual heat value in the liquor withdrawn in top separator is used to produce the necessary amount of steaming of the comminuted cellulosic material in ImpBin.
  • spent cooking liquor is withdrawn from end of digester, REC2, and preferably also from a withdrawal at liquor level in ImpBin, i.e. RECi, and sent further to evaporation plant ahead of final recovery in a recovery boiler.
  • ImpBin As colder comminuted cellulosic material are continuously fed into the ImpBin is this transition zone balanced with the amount of steam released in the chip volume, and the control of steam release is controlled by a temperature probe penetrating the chip volume (not shown). If the transition zone moves downwardly more return liquor TSRET is added or additional heating thereof, or alternatively using low pressure steam as a complementary steaming effect.
  • FIG. 4 shows in further detail the liquor routing in Compact Cooking G2.
  • the digester is operated with only 2 concurrent cooking zones, charging the white liquor WL to top of digester where it mixes well with the inflow of impregnated comminuted cellulosic material.
  • a L/W ratio of about 5 is established in first cooking zone and after this zone is hot partially spent cooking liquor, i.e. black liquor, withdrawn in a L/W ratio of about 3.
  • This hot black liquor is charged to start of transfer as shown in order to raise the temperature in the transport circulation where a L/W ratio of about 10-12 is established.
  • the top separator In the top separator is excess transport liquor withdrawn at a L/W ratio of about 6-8, and this transport liquor is sent to top of ImpBin to be released into the chip pile volume established above the liquor level, where steam is released.
  • the impregnation liquor for the ImpBin is established by the hot black liquor withdrawal which after mixing into the transport circulation for heating, is withdrawn in top separator and sent to top of ImpBin.
  • the black liquor is thus given an increased retention time in the cooking system as it is recirculated back to ImpBin and maintained in first cooking zone.
  • the increased retention time is beneficial for increasing yield, as the hemicellulose dissolved early in cooking need time and high alkali concentration for cleaving off end groups to such an extent that it precipitates back on the cellulose.
  • the effect of hemicellulose precipitation is dependent on the H-factor exposure of the dissolved hemicellulose.
  • the temperature established in the liquor level is about 100-102°C and the only heating subjected to the comminuted cellulosic material during impregnation is the heat release due to exothermic reactions, reaching about 1 10°C in bottom. This low temperature results in a minimal H-factor and neglectable alkali consumption due to delignification reactions.
  • the invention is all about a further improvement of the Compact Cooking G2 concept, where increased yield is one of the major objectives for the cooking concept. It has surprisingly been realized that the ImpBin concept used in Compact Cooking G2 is beneficial for recovery of heat value in cooking liquors and thus reducing heating costs, i.e. need for fresh steam. Even though total yield is high in a Compact Cooking G2 process, it has shown that the order of delignification in last phase of cooking is low, typically is the kappa number reduction in last half of cooking zone in the order of 15-20, while the kappa number reduction in first half is in the order of 60-100. . For cooking system operated according to design the carry over of COD in the digester blowline is in the range of 500-700 kg/adt.
  • the invention is an improvement of a method for cooking comminuted cellulosic material in which method is used a two vessel continuous digester system
  • the impregnation vessel having a withdrawal screen at the liquor level and wherein the withdrawal screen withdraws at least 1 -2 ton liquor/bdt wood of the impregnation liquor, said liquor containing at least a part of the wood acidity released during steaming in the chip volume above liquor level;
  • the cellulosic material is impregnated with the pressure released impregnation liquor during the retention time in the impregnation vessel,
  • -in the top of the digester is at least 4 ton liquor/bdt wood of the transport slurry withdrawn and used as the hot impregnation liquor added to the impregnation vessel; -and that a full digester temperature in the interval 130-170°C is established in a cooking zone in the digester using at least 80% of the total retention time of said digester as a cooking zone;
  • digester withdrawal screen in the middle of the cooking zone at a position in the digester corresponding to 35-60% of the total retention time in the digester, and wherein the cooking withdrawal screen withdraws at least 2.5 ton liquor/bdt wood establishing a first part of the cooking zone with high L/W ratio and a second part of the cooking zone with low L/W ratio, which withdrawn liquor is charged during feed out of impregnated comminuted material from the impregnation vessel as black liquor at full cooking temperature.
  • What is defined in preceding part is the preconditions for a two vessel Compact Cooking system with an ImpBin and using CrossCirc in transfer circulation.
  • the invention is characterized in that in this context is an additional volume of at least 0.5 ton liquor/bdt wood of wash filtrate from a subsequent brown wash position after the digester added to the center of the digester vessel at the digester withdrawal screen after heating the wash filtrate to full digester temperature, said wash filtrate having a lignin content less than 50% of the lignin content in the black liquor withdrawn in the withdrawal screen,
  • a further embodiment of the inventive method is fresh alkaline liquor charged to the two vessel digester system in a total charge of 160-190 (HW) and 190-230 (SW) kg alkali/bdt wood (EA as NaOH) in at least 3 process positions, wherein a first charge is added to the top of the digester in an amount exceeding 60% of the total charge of fresh alkaline liquor, and a second charge to the hot impregnation liquor and a third charge to the wash filtrate added to the center of the digester vessel at the digester withdrawal screen.
  • HW 160-190
  • SW 190-230
  • EA alkali/bdt wood
  • the amount of fresh alkaline liquor charged to the wash filtrate added to the center of the digester vessel at the digester withdrawal screen corresponding to at least 10% of the total charge of fresh alkaline liquor, wherein the charge is sufficient to establish an initial alkali level in the cooking zone over 10 g/l (EA as NaOH), and preferably above 15 g/l.
  • EA initial alkali level in the cooking zone over 10 g/l
  • the inventive method is the amount of fresh alkaline liquor charged to the wash filtrate charged to a cooking circulation recirculating a part of the liquor withdrawn from the digester withdrawal screen to the center of the digester vessel. This enforced circulation could improve radial distribution of the modified cooking liquor ahead of the final cooking zone.
  • the inventive is also the amount of fresh alkaline liquor charged to the hot impregnation liquor corresponding to at least 10% of the total charge of fresh alkaline liquor, wherein the charge is sufficient to establish a final residual alkali level in the impregnation vessel over 8 g/l (as NaOH), and preferably above 15 g/l.
  • a charge control could guarantee that sufficient amount of alkali is present during the entire impregnation, safeguarding that the alkali diffusion into the comminuted cellulosic material continues during the entire residence time in the impregnation vessel.
  • the wash filtrate from a subsequent brown wash position after the digester obtained from a pressurized wash, maintaining the pressure of the wash filtrate before addition to digester. If the wash filtrate is kept pressurized the temperature may be equal to or exceed the corresponding amount of spent impregnation liquid that is withdrawn from the impregnation vessel, improving heat economy of the two vessel system.
  • the wash filtrate from a subsequent brown wash position after the digester obtained from a pressurized wash maintaining the temperature of the wash filtrate before addition to digester above 100°C, and preferably in the range 100-1 10°C.
  • the wash filtrate could preferably be obtained from a subsequent brown wash position immediately after the digester, preferably in a pressure diffuser.
  • the wash filtrate from a subsequent brown wash position after the digester may alternatively be obtained from a wash after an oxygen delignification stage, maintaining the temperature of the wash filtrate before heating and addition to digester in the range 85-95°C or above.
  • Such a high temperature wash filtrate may still be beneficial for reducing the heat losses, as the temperature loss is only 5-15°C higher temperature in liquor withdrawn from the impregnation vessel than the wash filtrate added to digester.
  • liquor-to-wood / L/W ratio used, meaning the total amount of liquid in ton per ton of bone dry wood (bdt).
  • the example use a minimum charge of an additional volume of wash liquor of at least 0.5 in L/W, in order to indicate the minimum order of liquor charged.
  • the invention may be applied with increasing volumes up to a L/W ratio up to 2, or even more of the added liquor volume charged as wash liquor and then passed on through the system via first transport circulation and finally to impregnation vessel.
  • This cleaner wash liquor WL is heated in a heat exchanger HE to full cooking temperature before addition.
  • the wash liquor is preferably a wash liquor from a subsequent brown wash position, either from a wash directly after the digester or a wash after pre-bleaching or oxygen delignification, where the wash liquor still is alkaline.
  • the temperature of the wash liquor from a brown wash position is typically in the order of 90-1 10°C, and in the lower range if the washing is done in wash machines collecting the wash filtrate in atmospheric filtrate tanks, and in the upper range if the washing is done in wash machines keeping the wash filtrate pressurized.
  • the COD content in such brown wash positions is typically in the order of 30-80 g/l filtrate, which could be compared with the COD content of the mid screen withdrawal in digester which typically may be about 200 g/l, and thus higher COD content at end of cooking zone and before the bottom wash.
  • a corresponding additional amount of black liquor i.e. in a L/W ratio of at least 0.5, is withdrawn from the withdrawal screen and sent to start of transfer.
  • This additional amount of hot black liquor will elevate the temperature in the transport circulation, as the part of the hot black liquor in the transport liquor increases.
  • the excess transport liquor withdrawn from top separator but now at an increased volume in a L/W ratio of at least 0.5 of the increase.
  • ImpBin withdrawal screen is also the withdrawal volume increased at an increased volume in a L/W ratio of at least 0.5. This modification leaves the cooking process otherwise unaffected as to liqour-to- wood ratios during impregnation or cooking, maintaining the advantages of the Compact Cooking G2 process.
  • a cooking circulation CC be installed, that promotes an enhanced radial distribution of the new cooking liquor.
  • a cooking circulation normally includes also a pump (not shown).
  • ImpBin the extra amount of steam flashed off in the ImpBin will reduce the need for adding extra steam, i.e. LP-steam, to top of ImpBin.
  • This reduction of steam addition match the need for heating the wash liquor in heater HE, so in aspects of heat economy the change is not increasing steam consumption.
  • ImpBin screen In the boundary limits of the two vessel system is an additional volume of wash liquor added to the digester and the corresponding amount of recovery withdrawal increase is done from ImpBin screen. If these volumes are identical and the temperature in the ImpBin withdrawal is about 100°C, then no increased cost of steam is caused in the two vessel digester system if the wash liquor has the same temperature, i.e. 100°C, before heating. For each degree of temperature increase in wash liquor is the steam economy improved as less fresh steam (LP steam) needs to be added to ImpBin top as a result or if the steam to the ImpBin is enough the hot black liquor will be used to increase the temperature of the transfer circulation and the MP-steam demand on the digester top to reach cooking temperature will reduce.
  • LP steam fresh steam
  • the COD content in mid-point withdrawal at some 200 g/l. If no dilution of the cooking liquor and addition of alkali is made at this position the COD content will increase further during the final cooking zone.
  • the first phase of the cook is performed with high level of dissolved organic content, primarily hemicellulose and lignin in almost equal proportions, but then the final phase is modified slightly, decreasing the concentration of lignin and optionally increasing the alkali concentration for the final phase of the cook.
  • This modification of the cooking liquor improves delignification, such the typical low order of delignification that could be obtained in final delignification, reaching a kappa reduction in the order of 15-20 units, may be increased by at least 5-10 units.
  • FIG 6 a preferred brown wash in form of a pressure diffuser washing the pulp coming directly from the blow line of the digester.
  • This system installation follow the DiConnTM concept sold by Valmet, where the filtrate obtained from the pressured diffuser is kept pressurized making it possible to maintain the temperature of the wash filtrate above 100°C.
  • the wash filtrate from the pressure diffuser collected in an atmospheric filtrate tank that will flash off any heat value above boiling point.

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  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)

Abstract

L'invention concerne un système de cuisson à deux cuves amélioré, où la première cuve est une cuve d'imprégnation atmosphérique et la deuxième cuve est un digesteur sous pression, où la liqueur noire chaude est finalement évaporée à l'intérieur de la cuve d'imprégnation pour traiter à la vapeur la matière cellulosique et fournir la liqueur d'imprégnation. Selon le procédé de l'invention, une liqueur de nettoyage supplémentaire plus propre est chauffée et ajoutée à la zone de cuisson finale dans un digesteur, tout en déplaçant une quantité correspondante de liqueur noire chaude avant la zone de cuisson finale, et la quantité de chaleur dans la liqueur noire chaude est d'abord récupérée dans la circulation de transport avant d'être utilisée comme source pour évaporer la vapeur utilisée pour traiter à la vapeur le matériau cellulosique moulu à l'intérieur de la liqueur d'imprégnation et une utilisation finale comme liqueur d'imprégnation. L'invention permet d'obtenir un processus de cuisson avec un rendement élevé et une délignification améliorée en phases de cuisson finales et une teneur en DCO réduite dans la pâte à papier produite sans augmenter la consommation de vapeur.
PCT/SE2015/051161 2014-11-07 2015-11-04 Procédé de fonctionnement d'un système de digesteur à deux cuves WO2016072919A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
BR112017009620-0A BR112017009620B1 (pt) 2014-11-07 2015-11-04 Método para cozinhar material celulósico triturado
EP15857624.9A EP3215672B1 (fr) 2014-11-07 2015-11-04 Procédé de fonctionnement d'un système de digesteur à deux cuves

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE1451340-2 2014-11-07
SE1451340A SE538452C2 (en) 2014-11-07 2014-11-07 Method for operating a two vessel digester system

Publications (1)

Publication Number Publication Date
WO2016072919A1 true WO2016072919A1 (fr) 2016-05-12

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PCT/SE2015/051161 WO2016072919A1 (fr) 2014-11-07 2015-11-04 Procédé de fonctionnement d'un système de digesteur à deux cuves

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EP (1) EP3215672B1 (fr)
BR (1) BR112017009620B1 (fr)
CL (1) CL2017001066A1 (fr)
SE (1) SE538452C2 (fr)
WO (1) WO2016072919A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3464714A4 (fr) * 2016-05-27 2019-12-25 Valmet AB Charge d'alcali double pour imprégnation de copeau

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995013419A1 (fr) * 1993-11-08 1995-05-18 Kamyr, Inc. Realisation de la regulation des niveaux de solides dissous
WO1996002698A1 (fr) * 1994-07-18 1996-02-01 Pulp And Paper Research Institute Of Canada Cuisson de pate kraft en deux etapes
WO2000011261A1 (fr) * 1998-08-24 2000-03-02 Kvaerner Pulping Aktiebolag Procede permettant de precipiter de l'hemicellulose sur des fibres afin d'ameliorer le rendement et l'aptitude au raffinage
WO2000043589A1 (fr) * 1999-01-22 2000-07-27 Andritz-Ahlstrom Oy Traitement de filtrats recycles dans la production de la pate a papier
WO2003062525A1 (fr) * 2002-01-24 2003-07-31 Kvaerner Pulping Ab Cuisson en continu de pate a papier cellulosique avec une economie de chaleur amelioree
WO2011027029A1 (fr) * 2009-09-01 2011-03-10 Ak-Pulping Oy Procédé et ensemble pour le traitement de pâte cellulosique issue de l'industrie de transformation du bois

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995013419A1 (fr) * 1993-11-08 1995-05-18 Kamyr, Inc. Realisation de la regulation des niveaux de solides dissous
WO1996002698A1 (fr) * 1994-07-18 1996-02-01 Pulp And Paper Research Institute Of Canada Cuisson de pate kraft en deux etapes
WO2000011261A1 (fr) * 1998-08-24 2000-03-02 Kvaerner Pulping Aktiebolag Procede permettant de precipiter de l'hemicellulose sur des fibres afin d'ameliorer le rendement et l'aptitude au raffinage
WO2000043589A1 (fr) * 1999-01-22 2000-07-27 Andritz-Ahlstrom Oy Traitement de filtrats recycles dans la production de la pate a papier
WO2003062525A1 (fr) * 2002-01-24 2003-07-31 Kvaerner Pulping Ab Cuisson en continu de pate a papier cellulosique avec une economie de chaleur amelioree
WO2011027029A1 (fr) * 2009-09-01 2011-03-10 Ak-Pulping Oy Procédé et ensemble pour le traitement de pâte cellulosique issue de l'industrie de transformation du bois

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
CHEMICAL PULPING PART 1, FIBRE CHEMISTRY AND TECHNOLOGY, vol. 6, no. 2nd edition, pages 350 - 356, XP009502774, ISBN: 978-952-5216-41-7 *
See also references of EP3215672A4 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3464714A4 (fr) * 2016-05-27 2019-12-25 Valmet AB Charge d'alcali double pour imprégnation de copeau

Also Published As

Publication number Publication date
CL2017001066A1 (es) 2017-12-29
SE1451340A1 (sv) 2016-05-08
BR112017009620B1 (pt) 2022-04-12
BR112017009620A2 (pt) 2017-12-19
EP3215672B1 (fr) 2019-01-23
EP3215672A1 (fr) 2017-09-13
EP3215672A4 (fr) 2018-05-02
SE538452C2 (en) 2016-07-05

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