EP0635080B1 - Verfahren zur zellstoffherstellung - Google Patents

Verfahren zur zellstoffherstellung Download PDF

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Publication number
EP0635080B1
EP0635080B1 EP93907878A EP93907878A EP0635080B1 EP 0635080 B1 EP0635080 B1 EP 0635080B1 EP 93907878 A EP93907878 A EP 93907878A EP 93907878 A EP93907878 A EP 93907878A EP 0635080 B1 EP0635080 B1 EP 0635080B1
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EP
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Prior art keywords
organic solvent
solvent
fibrous material
cook
alkali
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EP93907878A
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English (en)
French (fr)
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EP0635080A1 (de
Inventor
Kari Ebeling
Kaj Henricson
Torolf Laxen
Bruno LÖNNBERG
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Ahlstrom Corp
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Ahlstrom Corp
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    • 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
    • D21C3/222—Use of compounds accelerating the pulping 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
    • D21C3/20—Pulping cellulose-containing materials with organic solvents or in solvent environment

Definitions

  • the present invention relates to a new method of producing chemical pulp.
  • the invention is an improvement in solvent cooking methods (e.g. organic solvent digestion), often referred to as "solvent pulping", being generally as described in U.S.-A- 3,585,104.
  • Wood comprises cellulosic fibres with lignin both inside the fibres and between the fibres, bonding the fibres together.
  • the lignin must be removed from between the fibres, the removal usually being accomplished by dissolving the lignin.
  • the cooking liquors consist of sodium hydroxide (i.e. soda cook), sodium hydroxide containing sodium sulphide (i.e. sulphate or kraft cook, also called alkaline cook), or, for example, sulphite ions sulphite cook, also called acid sulphite cook).
  • Lignin can also be removed by some organic solvents (hence the commercial name organosolv-process), the best known of which are methanol and ethanol. Formic acid is another proposed organic solvent.
  • Methanol and ethanol can be utilized as solvents in both alkaline and acid cooks.
  • the advantage of acid cooks is the simple recovery of the chemicals, as wood contains acids that make the cook acid, when only methanol or ethanol are used as solvents.
  • the disadvantage of acid cooks is the poor quality of the produced pulp, because the cellulosic fibres will, to some extent, degrade in acid treatment. In alkaline cooks the quality of the produced pulp will remain good, but the problem in alkaline cooks is the recovery of chemicals. Some alkali, mostly a sodium-based alkali, will firstly have to be added into the cook and then recovered and used again.
  • a known alkaline organic solvent process is the "Organo-cell-process", presently being used in Germany, in which process the cook is a soda-methanol cook.
  • the pH of the cook can be kept in the desirable range (generally neutral) by removing the acids from the beginning of the cook, i.e. almost immediately after they are formed.
  • the pH generally neutral By keeping the pH generally neutral, the pulp quality is enhanced, both for continuous and batch cooking processes. This is accomplished, in general, by countercurrent flow during continuous cooking, and in batch cooking by withdrawing solvent from the batch digester after a predetermined time from the start of the cook (and perhaps periodically thereafter), while the cook continues after the solvent withdrawal, with new solvent added.
  • a method of producing cellulose pulp from comminuted cellulosic fibrous material by organic solvent pulping comprising the step of (a) controlling the pH of the material during cooking so that it is generally neutral by removing acids formed at the start of the cook together with organic solvent used in the cook and by adding alkali to the cellulosic fibrous material in an amount sufficient to maintain the pH at the desired value.
  • This method may be practised utilizing a treatment vessel, comprising further the further steps of: (b) Causing the cellulosic fibrous material to flow in a first direction into the treatment vessel, and to be removed from the treatment vessel in the same, first, direction, whereby the needed amount of alkali is added to the material prior to the treatment vessel; and (c) introducing an organic solvent containing liquid stream to dissolve the lignin of the cellulosic fibrous material into the treatment vessel in a second direction, opposite the first direction.
  • Step (a) is practised by removing the acids formed during pulping, together with spent organic solvent, from the treatment vessel.
  • a method of producing cellulose pulp from comminuted cellulosic material by organic solvent pulping is known from DE-B-2644155. Further, such a method is also known from WO-A-8200483.
  • a method of producing cellulosic pulp from comminuted cellulosic fibrous material by solvent pulping comprising the steps of:
  • Figure 1 illustrates a schematic representation of the principle of a countercurrent cook/extraction treatment vessel/stage 20 according to the invention.
  • the number 10 refers to comminuted cellulosic fibrous material (e.g. wood) being fed into the process and the number 11 refers to cellulosic fibres of the wood, produced by dissolving and extracting lignin from the wood.
  • the number 12 refers to the organic solvent being fed to the process and the number 13 refers to the spent organic solvent being exhausted from the process, with dissolved lignin also present.
  • the process of Fig. 1 was examined in laboratory conditions with the surprising result shown in Fig. 6.
  • the pulp quality can be further improved by adding alkali to the countercurrent cook at the beginning of the cook. This case is shown in Fig. 7 by curve 102.
  • the alkali added in the beginning increases the pH and acids formed or dissolved neutralize the cook and the pH decreases to an almost neutral value during the countercurrent cook.
  • a countercurrent extraction according to Fig. 2 ensures that the pH does not decrease at the initial stages of the cook/extraction 20.
  • the amount of acid forming at the initial stages of the cook is 8-20 kg/ton of pulp, and an amount of alkali corresponding to the amount of acid is added, if the pH is to be kept out of the acid range (e.g. generally neutral, for example a pH of about 6.5 - 7.5). Due to the essentially completely countercurrent nature of the cook there is some alkali present at the initial stages of the cook 20, but it is then washed away and removed with the dissolved lignin in stream 13.
  • the residual solvent in the stream of fibres subsequent to the extraction 20 must be washed away as shown in Fig. 3.
  • the stream 11 of fibres is a mixture of organic solvents and wood fibres. Because of the countercurrent nature of the cook/extraction, it can be presumed that the fibres are suspended in nearly pure solvent.
  • the solvent is washed away with washing liquid 16, mostly water.
  • the result is a wood fibre-water suspension 15 and a solution 17 of water and solvent, mostly a mixture of water and ethanol or methanol.
  • the solvent is recovered from stream 17 by a process according to, for example, Fig. 4.
  • the solution 17 of water and solvent is directed to distillation apparatus 22, where the water 18 and solvent 12 are separated.
  • the solvent 12 is directed to cook 20.
  • Fig. 4 it is possible to effect a wash in 21 with water and still maintain a high ethanol and/or methanol content in the actual cook 20.
  • the pulp, if any, still in the form of chips prior to the wash, is fiberized prior to the wash to optimize the wash.
  • the organic solvent 12 preferably has a substantially greater than 30% methanol and/or ethanol content.
  • Fig. 5 illustrates a process more developed than heretofore described.
  • the wood 30 introduced into the process is heated at the beginning of the cook by feeding steam 31 in the wood material in presteamer 23.
  • Alkali 32 is at the same time introduced into the wood material to increase the pH at the initial stage of the cook.
  • a catalyst 33 can be introduced during either the pretreatment 23 or at the beginning of the cook 20 to enhance the dissolving of lignin.
  • a commonly used catalyst in acid process is CaCl 2 .
  • the Ca 2+ ions are advantageous to the process, but on the other hand the amount of acid is detrimentally increased in the reaction 2Cl- + 2H+ ⁇ 2HCl.
  • Organic bases, such as amine can be used as catalysts in acid, neutral and alkaline processes. Ethanol or methanol 34 is added to make up for the losses of solvent in the process.
  • the process has further been complemented by treatment of the lignin-containing outlet liquid 36.
  • the outlet liquids 13 of the previous embodiments can also be treated accordingly.
  • the outlet stream 36 of solvent from the cook 20 mostly contains solvent, polysaccharides, lignin and water.
  • the mixture 36 is directed to distillation/evaporation stage 24, where the solvent, mostly ethanol and/or methanol 37, is separated from the water 38 and lignin and polysaccharide material 39.
  • the solvent 37 can be returned to the cook 20 together with the solvent 12 from the distillation stage 22, while the water and lignin material are directed to combustion apparatus 25 or other treatment device.
  • One possibility is to separate the lignin and to produce, for example, vanillin from the separated lignin.
  • the added alkali 32 if any, is directed to combustion apparatus 25 and can thereafter be reused, or, if desired, removed. Removal is typically practised if the amount of the added alkali is small, e.g. 10-50 kg/ton of pulp.
  • CaCl 2 was utilized as catalyst, the amount of which was 5-50 g/l (that is about 5-50 grams of catalyst per litre of material being treated).
  • the temperature of the cook was 195 °C and the duration of the cook 20 was 3 hours.
  • alkali 14, 32
  • Ethanol is probably a better solvent than methanol for the practice of the invention, but the deacetylation that occurs in the wood produces some methanol. Thus there is always some methanol present in the process, even if the only fresh solvent 34 is ethanol.
  • the invention can be applied to numerous cooks, both batch cooks and continuous cooks.
  • the invention can, for example, be utilized in continuous digesters with a pretreatment zone or in continuous digesters with a separate pretreatment vessel.
  • the acids produced at the beginning of the cook can be removed by withdrawing solvent from the digester after a predetermined time (e.g. about 5 - 10 minutes, but dependent upon material being cooked, the exact composition of the organic solvent, etc.) - the produced acids being removed with the solvent - and introducing at least some new solvent. While normally not necessary since most of the acids are produced within the first five minutes or so, the withdrawal and replacement procedure can be practised periodically if desirable.
  • the pH during batch cooking can alternatively, or in addition, be maintained generally neutral during the initial stages of the cook by adding alkali to the material prior to or simultaneously with introduction into the digester.
  • the invention may be further illustrated by the following examples.
  • the chips were pretreated in a pretreatment liquor consisting of NaOH dissolved in water.
  • the pretreatment time was about 30 minutes and the temperature 120 °C.
  • the idea of the pretreatment step was to cause the fibre to swell so as to enhance the subsequent ethanol extraction step.
  • Another reason for the pretreatment step was to enable the addition of alkali to the chips to keep the pH at a sufficiently high level during the rest of the cook.
  • the amount of alkali was varied between 0.25 to 1.50 mol NaOH/l. It was found that when the amount of alkali was below 0.25 mol NaOH/l the delignification was insufficient and the amount of unfiberized wood high. At alkali levels above 1.00 mol NaOH/l the yield loss in the cook became too high. Probably the amount of alkali actually needed depends on type of wood used. For the tested Scandinavian spruce the optimal alkali level was between 0.5 and 1.0 mol NaOH/l.
  • the chips were removed from the pretreatment liquor by lifting the chips out. It was found that about 30 - 70 kg of NaOH per ton of pulp was entrained with the chips.
  • Alkali had also been consumed in the pretreatment vessel.
  • the consumption was 50 - 300 kg NaOH per ton of pulp.
  • steps 1 and 2 were taken to a countercurrent ethanol extraction step.
  • the duration of this solvent extraction step was about 120 minutes and the temperature 185 °C.
  • Anthraquinone was added to the solvent to improve delignification.
  • the added amount of anthraquinone was between 0 and 1.0 mmol.
  • the strength of the ethanol solvent was varied between 25% and 100%. The lowest residual lignin contents were achieved when the ethanol content was between 40 and 70% in the liquid phase. When being tested for bleachability and pulp properties, the pulp was found to have pulp properties close to those of kraft pulp regarding both bleachability and strength.
  • FIG. 8 shows an apparatus with which the process of example 1 can be performed.
  • the apparatus comprises a conventional chips bin 201 connected by a conventional low pressure feeder 202 to a conventional horizontal steaming vessel 203, which in turn is connected by a conventional chute to a conventional high pressure feeder 204.
  • Wood chips are first steamed and preheated and then taken through the first pressure feeder 204 in line 205 to the pretreatment vessel 206 in which the chips are treated in an alkaline solution.
  • the alkaline solution is introduced into the system in line 207.
  • a conventional liquid/ material separator system is provided at the top of the vessel, with withdrawn liquid recirculated via line 208 to the inlet high pressure port of the feeder 204.
  • the alkali can come from one or several of the following sources:
  • the chips are taken to the extraction zone 215 in the second pressure vessel 213 in which the pressure is much higher than in pressure vessel 206.
  • the chips material passes via line 211 to the top of the vessel 213 from a high pressure feeder 209 in the bottom of the pretreatment vessel 206.
  • a conventional liquid/material separator system is provided at the top of the vessel 213, with withdrawn liquid recirculated via line 212 to the inlet high pressure port of the feeder 209.
  • the liquid is passed through a heat exchanger 210.
  • the second vessel 213 preferably consists of two zones: (1) zone 215 in which the chips are extracted with ethanol/methanol; and (2) zone 216 in which the chips are washed before being discharged from the vessel.
  • washing liquid Filtrate from a subsequent washing or bleaching step is used as washing liquid.
  • the washing liquid is introduced into the bottom of the vessel 213 through line 218.
  • the pulp at the bottom of the vessel 213 is washed and discharged into line 219.
  • the ethanol and/or methanol is added at a point above the washing zone 216 in line 217.
  • the ethanol is introduced at such a strength and amount that optimal extraction conditions are achieved in the extraction zone 215. If necessary, water can be separated from the circulation 220 by distillation to control methanol/ethanol strength in the extraction zone 215.
  • the extraction liquor is withdrawn from the extractor/digester 213 into a withdrawal conduit 214.
  • the withdrawn liquor containing the alkali used, the ethanol/methanol used and the dissolved lignin, is taken to recovery.
  • FIG. 9 A simplified recovery system for solvent and alkali is shown in Fig. 9.
  • the extraction liquor 214 from Fig. 8 is treated in the following steps: (a) Ethanol/methanol separation (250). The solvent is then reused in the extraction vessel 213. (b) Evaporation (252) in which water is separated. (c) Combustion (254) of lignin and polysaccharides.
  • melt (255) consisting essentially of Na 2 CO 3 is produced. This melt is dissolved in water and used as a Na 2 CO 3 containing liquid in the pretreatment vessel 206 or causticized to NaOH before using in the pretreatment vessel 206. If the Na 2 CO 3 amount is small it does not have to be reused.
  • Fig. 10 illustrates a diagram of a process in which the initial bleaching is effected by oxygen and the actual final bleaching by ozone and peroxide.
  • the wood chips 300 that are introduced into the process are first heated by feeding steam 301 to the wood material to a pretreatment vessel 323.
  • Alkali 302 is at the same time introduced into the wood material so that the chips are treated at a pH of 11 - 12.
  • the alkali is obtained from the bleach plant effluents, which contain 40 - 120 kg of NaOH/adt. If the volume of the effluent is too big, the effluent has to be evaporated in order to reduce the volume. Additional alkali is brought if needed in the form of NaOH or Na 2 CO 3 .
  • the chips 310 are introduced to the extraction stage 320 where some methanol and/or ethanol 312' may be added in the beginning to control the liquor- to - wood ratio, or to increase the content of methanol/ethanol in the beginning of the extraction process 320.
  • the chips 311 are washed with the bleach plant effluents 302', 303, 304, which may be acid or alkali depending on how the bleaching has done. If possible, the acid filtrates 303 and 304 are used in the washing 321 and the alkali filtrate 302 in chips pretreatment 323.
  • the washing liquid 317 containing solvent may have to be strengthened by distillation 322 before adding methanol and/or ethanol 312 to the extraction stage 320.
  • the pulp 315 from the washing stage is introduced into the bleach plant 330 in which the pulp is bleached in the sequence OZP.
  • the waste liquor 306 is recovered, evaporated and combusted. If the alkali amount is low, the Na 2 CO 3 formed in the recovery process is removed from the mill and fresh NaOH is brought in. Some of the Na 2 CO 3 may be used in the pretreatment stage. If the amount of alkali in the effluent stream is large it is probably more practical to causticize the formed Na 2 CO 3 to NaOH and thus generate new NaOH for bleaching and pretreatment at the mill.
  • the wood was pretreated with a mixture of 75 % Na 2 CO 3 and 25 % NaOH in amount that corresponds about 200 kg Na/adt expressed as NaOH. This means that about 50 kg/adt of NaOH was used and the rest was Na 2 CO 3 .
  • the amount of NaOH needed in the bleaching sequence OZEP is also about 50 kg/adt.
  • all alkali needed in the pretreatment of the chips in the form of NaOH is received from the bleach plant effluent water.
  • the rest of the alkali can be used as Na 2 CO 3 which is the form of the Na when burning the residual liquor in a recovery boiler.
  • a mill does not need any causticizing plant, but uses Na 2 CO 3 from the combustion of spent liquor and NaOH from bleach plant effluents.
  • Filtrates from the bleach plant can be used to dissolve the Na 2 CO 3 from the recovery boiler thus further reducing the water effluent volume.
  • Fig. 11 also illustrates a schematic technical diagram of a process in which the initial bleaching is effected by oxygen and the actual final bleaching by ozone and peroxide.

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Claims (18)

  1. Verfahren zur Herstellung von Zellstoff aus zerkleinertem zellulosehaltigem Fasermaterial durch Aufschluß mit organischem Lösemittel, dadurch gekennzeichnet, daß
    (a) das zerkleinerte zelluloschaltige Fasermaterial mit alkalischer wäßriger Lösung zur Schwellung des Fasermaterials vorbehandelt wird, um das Eindringen von Lösemittel zu verbessern und den pH anzuheben, so daß der pH des Materials während des Solvent-Aufschlusses zumindest neutral bleibt;
    (b) das vorbehandelte zelluloschaltige Fasermaterial mit einer organisches Lösemittel enthaltenden Flüssigkeit behandelt wird und das Lignin des Materials mit dem Lösemittel extrahiert wird; und daß
    (c) das behandelte zelluloschaltige Fasermaterial gewaschen wird, um das aufgelöste Lignin zu entfernen und extrahieren und um die Beseitigung unerwünschter Chemikalien daraus zu bewerkstelligen.
  2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß die Schritte (b) und (c) durch Gegenstrom-Extraktion und -Wäsche ausgeführt werden.
  3. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß die Schritte (a), (b) und (c) im wesentlichen kontinuierlich praktiziert werden.
  4. Verfahren nach Anspruch 2 oder 3, dadurch gekennzeichnet, daß die Schritte (b) und (c) durch Anwendung eines Behandlungsbehälters praktiziert werden, wobei
    - das zelluloschaltige Fasermaterial veranlaßt wird, in einer ersten Richtung in den Behandlungsbehälter zu fließen und aus dem Behandlungsbehälter in der gleichen ersten Richtung entfernt zu werden, wobei die gebrauchte Alkalimenge dem Maleriai vor dem Behandlungsbehälter zugesetzt wird; und
    - ein organisches Lösemittel enthaltender Flüssigkeitsstrom in den Behandlungsbehälter in einer zweiten, der ersten Richtung entgegengesetzten Richtung eingeführt wird, um das Lignin des zellulosehaltigen Fasermaterials aufzulösen; und die beim Aufschluß gebildeten Säuren mit dem Gegenstrom verbrauchten organischen Lösemittels aus dem Behandlungsbehälter entfernt werden.
  5. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß das verbrauchte organische Lösemittel von Schritt (b) extrahiert und behandelt wird, um organisches Lösemittel aus dem aufgelösten Material darin zu entfernen.
  6. Verfahren nach Anspruch 5, dadurch gekennzeichnet, daß das abgeschiedene organische Lösemittel von der Abscheidestufe eingeführt wird, um als organisches Lösemittel in Schritt (b) benutzt zu werden.
  7. Verfahren nach Anspruch 5, dadurch gekennzeichnet, daß das abgeschiedene, in der Abscheidestufe vom organischen Lösemittel entfernte Material verbrannt wird, um eine Na2CO3 haltige Schmelze zu erzeugen, und die Schmelze in Wasser aufgelöst wird, um eine Flüssigkeit zu produzieren, die als Alkali ohne oder nach Kaustizierung verwendet und dem zellulosehaltigen Fasermaterial in Schritt (a) zugeführt wird.
  8. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß einige der während der Wäsche entfernten Chemikalien organisches Lösemittel enthalten, das aus der Waschflüssigkeit abgeschieden und Schritt (b) zugeführt wird.
  9. Verfahren nach Anspruch 8, dadurch gekennzeichnet, daß das organische Lösemittel durch Destillation aus der Waschflüssigkeit abgeschieden wird.
  10. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß das zelluloschaltige Fasermaterial vor oder während Schritt (a) gedämpft wird.
  11. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß ein Katalysator zur Verbesserung der Auflösung von Lignin dem zellulosehaltigen Fasermaterial vor Schritt (b) zugeführt wird.
  12. Verfahren nach Anspruch 11, dadurch gekennzeichnet, daß der Katalysator aus einer Gruppe gewählt wird, die im wesentlichen aus Salzen von Alkali-Erdmetallen, Anthrachinonen und organischen Basen besteht, und daß ungefähr 5 - 50 Gramm Katalysator pro Liter Behandlungsgutes zugesetzt werden.
  13. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß der Aufschluß in einem diskontinuierlichen Kocher praktiziert wird, indem verbrauchtes Lösungsmittel enthaltende gebildete Säuren aus dem Kocher entfernt werden, sobald sich die überwiegende Mehrheit der Säuren zu Beginn des Aufschiusses gebildet hat
  14. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß das organische Lösemittel in der organisches Lösemittel enthaltenden Flüssigkeit aus einer Gruppe gewählt wird, die im wesentlichen aus Methanol, Äthanol, und Mischungen von Methanol und Äthanol besteht.
  15. Verfahren nach Anspruch 14, dadurch gekennzeichnet, daß die Menge an Methanol, Äthanol und Mischungen von Methanol und Äthanol wesentlich grösser als 50 % der Gesamtmenge der Lösemittel enthaltenden Flüssigkeit ist.
  16. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß NaOH als Alkali in Schritt (a) verwendet wird.
  17. Verfahren nach Anspruch 16, dadurch gekennzeichnet, daß auch Na2CO3 als Alkali in Schritt (a) verwendet wird.
  18. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß das zelluloschaltige Fasermaterial in Schritt (c) mit Wasser gewaschen wird.
EP93907878A 1992-04-06 1993-04-01 Verfahren zur zellstoffherstellung Expired - Lifetime EP0635080B1 (de)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
US86397792A 1992-04-06 1992-04-06
US863977 1992-04-06
US1911393A 1993-02-17 1993-02-17
PCT/FI1993/000137 WO1993020279A1 (en) 1992-04-06 1993-04-01 Method of producing pulp
US19113 1998-02-05

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EP0635080A1 EP0635080A1 (de) 1995-01-25
EP0635080B1 true EP0635080B1 (de) 1997-03-12

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EP (1) EP0635080B1 (de)
JP (1) JP2667058B2 (de)
AT (1) ATE150112T1 (de)
CA (1) CA2133574C (de)
DE (1) DE69308831T2 (de)
RU (1) RU2084574C1 (de)
WO (1) WO1993020279A1 (de)

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US5788812A (en) * 1985-11-05 1998-08-04 Agar; Richard C. Method of recovering furfural from organic pulping liquor
FI122838B (fi) 2005-03-31 2012-07-31 Metso Paper Inc Menetelmä massan valmistamiseksi lignoselluloosamateriaalista
US20100285550A1 (en) * 2008-01-11 2010-11-11 Novozymes A/S Delignification of Lignocellulose-Containing Material
FR2937656B1 (fr) * 2008-10-24 2010-11-19 Arkema France Procede de fabrication de pate a papier
JP2013042727A (ja) * 2011-08-26 2013-03-04 Kawasaki Heavy Ind Ltd リグノセルロース系バイオマスからエタノールを製造する方法及びその前処理方法
CN105239435B (zh) * 2015-09-02 2018-03-27 广州市楹晟生物科技有限公司 一种木质纤维原料的处理方法
CN110194446B (zh) * 2019-06-10 2022-05-13 广西科学院 一种以纤维素深度水解得到的2d纤维素为原料的石墨烯2d粉体的制备方法
CN114645479B (zh) * 2020-12-19 2023-07-25 山东洲星天然物提取智能设备有限公司 一种纸浆的制备方法
EP4023813A1 (de) * 2020-12-29 2022-07-06 Technische Universität Wien Verfahren zur herstellung von produkten auf basis von holz als rohstoff
EP4023812A1 (de) * 2020-12-29 2022-07-06 MM BOARD & PAPER GmbH Verfahren zur herstellung von produkten auf basis von holz als rohstoff

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Publication number Priority date Publication date Assignee Title
US3585104A (en) * 1968-07-29 1971-06-15 Theodor N Kleinert Organosolv pulping and recovery process
DE2644155C2 (de) * 1976-09-30 1978-07-27 Theodor N. Dr. Pointe Claire Quebec Kleinert (Kanada) Kontinuierliches Aufschluß- und Ruckgewinnungsverfahren für pflanzliche Faserrohstoffe zur Herstellung von Zellstoff im organischen Lösungsmittel
CA1150012A (en) * 1980-07-25 1983-07-19 Pei-Ching Chang Aqueous catalysed solvent pulping of lignocellulose

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RU2084574C1 (ru) 1997-07-20
CA2133574A1 (en) 1993-10-14
CA2133574C (en) 1997-12-30
RU94045883A (ru) 1996-08-20
EP0635080A1 (de) 1995-01-25
DE69308831T2 (de) 1997-07-31
DE69308831D1 (de) 1997-04-17
JPH07501860A (ja) 1995-02-23
JP2667058B2 (ja) 1997-10-22
WO1993020279A1 (en) 1993-10-14
ATE150112T1 (de) 1997-03-15

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