WO2004050983A1 - Procede et systeme de traitement de copeaux de bois - Google Patents

Procede et systeme de traitement de copeaux de bois Download PDF

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Publication number
WO2004050983A1
WO2004050983A1 PCT/SE2003/001778 SE0301778W WO2004050983A1 WO 2004050983 A1 WO2004050983 A1 WO 2004050983A1 SE 0301778 W SE0301778 W SE 0301778W WO 2004050983 A1 WO2004050983 A1 WO 2004050983A1
Authority
WO
WIPO (PCT)
Prior art keywords
chips
refining
wood
liquid
acidic leaching
Prior art date
Application number
PCT/SE2003/001778
Other languages
English (en)
Inventor
Harald Brelid
Peter AXEGÅRD
Original Assignee
Stfi, Skogsindustrins Tekniska Forskningsinstitut 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 Stfi, Skogsindustrins Tekniska Forskningsinstitut Ab filed Critical Stfi, Skogsindustrins Tekniska Forskningsinstitut Ab
Priority to AU2003279671A priority Critical patent/AU2003279671A1/en
Priority to BR0316938-3A priority patent/BR0316938A/pt
Publication of WO2004050983A1 publication Critical patent/WO2004050983A1/fr
Priority to SE0501175A priority patent/SE528369C2/sv
Priority to FI20055267A priority patent/FI20055267A/fi

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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
    • D21C1/00—Pretreatment of the finely-divided materials before digesting
    • D21C1/04—Pretreatment of the finely-divided materials before digesting with acid reacting compounds
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
    • D21B1/00—Fibrous raw materials or their mechanical treatment
    • D21B1/02—Pretreatment of the raw materials by chemical or physical means
    • D21B1/021—Pretreatment of the raw materials by chemical or physical means by chemical means
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21B—FIBROUS RAW MATERIALS OR THEIR MECHANICAL TREATMENT
    • D21B1/00—Fibrous raw materials or their mechanical treatment
    • D21B1/04—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres
    • D21B1/12—Fibrous raw materials or their mechanical treatment by dividing raw materials into small particles, e.g. fibres by wet methods, by the use of steam
    • D21B1/14—Disintegrating in mills
    • D21B1/16—Disintegrating in mills in the presence of chemical agents

Definitions

  • This invention concerns the technical field of wood chips treatment, wherein disturbing non- protfess elements can be disposed of, within the manufacture of mechanical pulp and chemimechanical pulp, i.e. RMP, TMP or CTMP (chemithermomechanical pulp). More specific the present invention relates to a method and a system for removing non-process elements without significant changes of the pulping process and the pulp quality.
  • RMP mechanical pulp and chemimechanical pulp
  • CTMP chemithermomechanical pulp
  • NPE's non-process elements
  • leaching of chips requires fairly long times to be effective and is further limited by the fairly large amount of liquor bound inside the chips after leaching.
  • the long time and a need of pressurised systems for the leaching of chips make a process equipment for NPE removal quite expensive in this case.
  • Chemical pulping does not allow strong mechanical treatment of the chips such as pressing due to the damages it would introduce to the final pulp fibres. Mechanical pulps on the other hand are not negatively affected. In fact, an initial pressing would even simplify the refining of the chips.
  • a process for the manufacture of mechanical pulp from wood is disclosed in FI 87371 where wood is chipped into chips which, in turn, after a pre-treatment are ground into pulp. Air is removed in the chips whereupon the chips are impregnated with water that may be acidic by use of a mineral acid. An introduction of cracks in the chips in order to shorten the diffusion ways within the wood material before impregnation, during a sufficient time period, and subsequent refining is not described. Thus non-process elements (NPE's) are removed only to a small extent due to diffusion problems as indicated earlier. This above deficit is also present in SE 451202, SE 468644 and FI 43668 which disclose similar processes.
  • Non-process elements cause problems during the pulp manufacture or later on when making paper or related products.
  • Mn e.g. is negative for the peroxide bleaching of the subsequent pulp, which is a dominating bleaching chemical for mechanical and chemimechanical pulps-such as RMP, TMP and CTMP.
  • the problems arising from NPE's become more severe when a closed process is used for the manufacture of pulp and/or paper due to a build-up of the concentrations of dissolved NPE's.
  • the amount of non-process elements can be reduced to an extent, which alleviates or eliminates the problems in the pulp and/or paper manufacturing processes as e.g. set out above.
  • the present invention solves the above problems by providing, according to a first aspect, a method for treatment of wood chips from softwood or hardwood or a mixture thereof for the reduction of non-process elements in a mechanical pulping process or a chemithermomechanical pulping process, without significant changes of the pulping process and the pulp quality, comprising the following steps: a) introduction of cracks in the chips or refining the chips to a coarse fibre structure, in order to considerably shorten the diffusion ways within the wood material, b) treatment of the chips or fibres thereof with an acidic leaching liquid, c) extensive removal of the acidic leaching liquid; and d) adjustment of the pH to a level suitable for refining, preferably pH ⁇ 4.
  • the present invention also provides, according to a second aspect, a system for using the method according to the first aspect, comprising the following components: i) means for introduction of cracks in wood chips or means for refining the chips to a coarse fibre structure, ii) means for treating the wood chips or fibre thereof with an acidic leaching liquor; and iii) means for adjusting the pH to a level suitable for refining.
  • refiner generally involves treatment of fibre material in water.
  • refiners are refiners equipped with refining discs (disc refiners).
  • a refiner generally operates continuously.
  • the introduction of cracks in the chips, in order to shorten the diffusion ways (in step a)) of the present invention is performed with a relatively small energy consumption preferably by using one or more disc refiners.
  • the energy consumption may be- in the range of approximately 500 kWh/ADt or somewhat less (airdry tonne), which creates a "soft" refining.
  • a "normal" refining may involve freeing the fibres using en energy input of from approximately 1500 to 2000 kWh/ADt whereby the temperature is between 120 and 160 °C.
  • the "soft" refining is performed at a temperature of from 60 to 100°C.
  • the refiner may further be pressurized if TMP or CTMP is the desired product. If RMP is to be produced the refiner does not need to be pressurized. If CTMP is desired also means for the addition of chemicals is necessary.
  • the lignocellulosic fibres that may be obtained when using the present invention include all types of softwood and hardwood-based fibres, unbleached and bleached mechanical (Refiner Mechanical Pulp; RMP) and thermo-mechanical pulps (TMP), Chemithermomechanical Pulp (CTMP) and mixtures of these.
  • RMP Refiner Mechanical Pulp
  • TMP thermo-mechanical pulps
  • CMP Chemithermomechanical Pulp
  • the expression "acidic leaching liquid” embraces any acidic liquid.
  • acidic leaching liquids are mineral acids such as sulphuric acid, which is preferred, or mixtures of such acids.
  • the acid(s) may be comprised in water or white water or a mixture thereof. The white water must obviously not contain too much NPEs.
  • the amount of leaching liquid in relation to the lignocellulose containing raw material may preferably be abundant.
  • the dilution rate may be high, thus enabling a positive equilibrium for diluting the NPE's present in the wood raw material.
  • the leaching step is preferably combined with other process step(s) in a mill producing pulp and/or paper.
  • the leaching step is preferably run at a lower pH than a subsequent refining step.
  • the removal of acidic leaching liquid in step c) may comprise washing of the fibres which may be performed by letting the leaching liquid just pour off the wood material, i.e. self-pouring of the leaching liquid, compressing screw feeder may additionally be used for removing the acidic leaching liquid in step c). If a CTMP pulp is desired, more thorough washing may be needed in order to reduce the resin (a process disturbing organic substance) contents. Additionally the wash liquid may, preferably at the end of the washing process, be more basic (alkaline) in order to obtain a better reduction of resin or extractives.
  • An embodiment for reducing the resin contents and NPE's is using counter-current flows (a liquid exchaiige) of alkaline white water (or fresh alkaline), respectively, during the washing step of the fibres or fibre bundles (which may be in the form of a pulp).
  • First an essentially alkaline counter-current wash flow treats the pulp interrupted by an essentially acidic stage and, finally, in the counter current wash flow alkaline washing stage treats the pulp.
  • alkaline solution or alkaline white water will be displaced by an acidic fresh solution or an acidic white water.
  • the acidic fresh solution or white water will be displaced by alkaline solution or White water.
  • the refining the chips to a coarse fibre structure, in order to shorten the diffusion ways (in step a)), may be achieved by a refiner and the introduction of cracks in the chips, in order to shorten the diffusion ways (in step a)) may be achieved by a compressing screw press.
  • the diffusion ways may be 1 mm or less after the introduction of cracks. If a refiner is used to perform step a), fibres or fibre bundles will be the predominant form of the chips, i.e. the raw material, after the introduction of cracks.
  • the resin is further preferably extracted after the refining by e.g. using alkaline conditions.
  • the removal of the acidic leaching liquid in step c) involves washing the pulp, preferably by using a fibre washing equipment.
  • the b) treatment of the chips with an acidic leaching liquid involves reacting the chips in a leaching vessel.
  • a fibre washing equipment is preferably connected to the vessel for use after the storing.
  • the fibre washing equipment may be a filter or other dewatering means such as a press or a compressing screw feeder as set out below.
  • the removal of the acidic leaching liquid in step c) is followed by a pH adjustment to a level suitable for chip refining, preferably pH > 4 as set out above in step d).
  • the b) treatment of the chips with an acidic leaching liquid is performed at a low consistency.
  • the refining of the chips to a coarse fibre structure in order to shorten the diffusion ways (distances) in step a) is performed in a refiner stage to a freeness > 300 CSF and preferably the removal of the acidic leaching liquid is performed in a fibre washing equipment, subsequently followed by a second refining stage.
  • CSF Canadian Standard Freeness
  • the b) treatment of the chips with an acidic leaching liquid, effectuating the removal of non-process elements and/or organic process disturbing substances is combined with an extensive resin (extractive) removal through multistage counter-current washing, wherein the acidic leaching stage is placed after the first washing stage in a predominantly alkaline washing system and the acidity in the leaching stage is maintained through a combination of liquid exchange and acid changing as set out above.
  • the acidic leaching liquid in step b) is make-up originating from purified re-circulated wash liquid, preferably purified washing liquid from a washing step, most preferred washing liquid emanating from step c).
  • the wash liquid may also be white water with origin elsewhere in the manufacturing process. The white water may be conveyed to the wash step through a white water system.
  • step b) ⁇ t> performed during a time period of approximately from 1 minute up to 1 hour, preferably 1 minute up to 30 minutes, most preferred 5 minutes up to 15 minutes, especially preferred approximately 10 minutes (for acid-sensitive wood species).
  • the pH adjustment in step d) comprises adjusting the pH in the range of 4-9, preferably by adding white water or water mixed with one or more basic compounds.
  • the refining of the chips to a coarse fibre structure in step a) comprises freeing the fibres to a freeness > 300 CSF, which may be achieved by using en energy input of from approximately 300 kWh/ADt.
  • the refining of the chips to a coarse fibre structure in step a) is performed at a temperature of from 60°C to 100°C.
  • the introduction of cracks in step a) involves treating the wood chips in a compressing screw feeder arrangement, preferably equipped with or connected to a shredding device, most preferred additionally equipped with or connected to a peg-mixer.
  • a compressing screw feeder (“PREX-skruv") arrangement.
  • This compressing screw feeder works like a pressure lock and will press the leaching liquid out through a drainage outlet.
  • a refiner follows, optionally including a pH- adjustment either before in the screw feeder, after said screw feeder or at the refiner inlet. If the pH adjustment is performed in the subsequent refiner it may be performed is conjunction with the addition of water.
  • the steps a) through d) are performed in an essentially closed process.
  • the resin depleting chemicals are added before or during the refining of the chips, or during the introduction of cracks in step a).
  • This treatment gives rise to Chemithermomechanical Pulp (CTMP) and provides a pulp of different qualities (typically "softer").
  • CTMP Chemithermomechanical Pulp
  • the chemicals may be sodium sulfite, (thus sulfonation of the lignin occurs which gives a "permanent" softening as compared to the temporary softening in the TMP process) and/or hydrogen peroxide in combination with alkali.
  • the chemical pre-treatment is preferably performed during steaming in combination with refining.
  • the freeness (CSF) may be high when using the above chemical treatment.
  • the sulfite treatments may range from 1-5% of the weight of the wood.
  • a thorough wash step is used to remove lignin and other dissolved compounds.
  • said wash step is comprised in step c).
  • the means for introduction of cracks in wood chips is a compressing screw feeder arrangement and the means for refining the chips to a coarse fibre structure is a refiner.
  • the system comprises a reaction vessel for treating the wood chips with an acidic leaching liquor, a leaching vessel.
  • the system comprises a wood fibre wash (pulp wash) arranged between the means for treating the wood chips with an acidic leaching liquor and the means for adjusting the pH to a level suitable for refining.
  • the wood fibre wash may comprise a compressing screw feeder.
  • the refiner preferably is equipped with a heating device and/or means for adding resin depleting chemicals. Also the steam produced during the operation of the refiner may be used and that steam may be enough, thus enabling the omission of the heating device.
  • the system comprises additionally a purification apparatus for purifying wash liquid connected to the wood fibre wash.
  • This purification apparatus may e.g. comprise a filter whereby larger components such as polymeric material may be removed. Smaller components such as NPE's or related compounds may be removed through flocculation by e.g. adding flocculation agents, or through flotation. You may let the small organic compounds stay in the white water.
  • the compressing screw feeder arrangement is equipped with or connected to a shredding device (for shredding the plug obtained in the screw feeder), preferably equipped with or connected to subsequent peg-mixer.
  • the compressing screw feeder is somewhat conical and the screw is adapted so that the elevation gives a certain compression of the wood material.
  • a compressing screw feeder may preferably be used to convey the chips.
  • the pulp, and eventually paper or paper board, obtainable by the method according to the first aspect of the present invention may e.g. be used, for the manufacture of any kind of paper or paper product.
  • the present invention provides a method according to the first aspect, which is inexpensive, has a good leaching yield (well over 50%) and provides fibres (and pulp) with a neutral colour (non- discoloured).
  • a good leaching yield well over 50%
  • a neutral colour non- discoloured
  • Extreme treatment times together with high temperatures can thus be avoided through the present invention.
  • the present invention provides a method whereby short treatment times and low treatment temperatures may be used. Accordingly extreme amounts of substance is not dissolved which could be harmful for the effluent.
  • Another advantage in comparison with e.g. chemical pulp is that the pulps above can be pressed. A dry substance of 40% or above may be achieved by pressing, thus the impregnated leaching liquor may be better disposed of.
  • FIG. 1 shows a part of a preferred embodiment of the present invention.
  • Wood chips with a wood density of 420 kg OD wood/m 3 moist volume (and about 3 % lower density of the solid chip material due to normal cracks in mill chips) are fed into a screw press, which compresses the wood to such an extent that a great many new cracks will considerably increase the water absorption capacity of the chips (from about 1.8 m 3 /OD ton of wood to at least 3) and hence decrease the diffusion distances within the solid wood material. To a varying degree the chips will be partially disintegrated, which will further facilitate the diffusion.
  • the screw press discharges the wood material into a screw conveyor, where the compressed chips are allowed to expand in acid make-up leaching liquor and a small amount of re-circulated leaching liquor required to maintain a liquor phase in the lower part of the conveyor.
  • the impregnated chips are then transported to the top of the non-pressurized leaching vessel, where they are distributed evenly over the cross-section by means of re-circulated excess leaching liquor pumped in through nozzles at the top of the vessel.
  • the vessel is designed to give a retention time for the chips of 10 to 15 minutes (normally at pH 2.5 and 80°C).
  • a bottom scraper in the leaching vessel helps to fill a discharging transport screw below the vessel. This screw feeds a screw conveyor with a liquor level high enough to secure a required liquor level in the leaching vessel. The chips are drained of free liquor at the top of the conveyor.
  • the drained chips are then fed to a transport screw, which distributes the wood material to the different refiners in the line (if more than one).
  • a transport screw which distributes the wood material to the different refiners in the line (if more than one).
  • a screw feeder for each refiner there is a screw feeder (a "PREX screw"), which compresses the wood material to such. an extent that it forms a plug serving as pressure lock between the atmospheric feeding system and the pressurized heat pretreatment of a normal TMP process.
  • the PREX screw can at the same time squeeze out a considerable amount of liquid from the chips.
  • the screw should therefore be designed to produce at least 40 % dry content, preferable 50%.
  • An important principle of the invention is to guarantee that the TMP process (or an RMP or CTMP process) can be run at normal conditions, without any disturbance from the leaching process.
  • One important issue is then to maintain a pH, which is optimal for the TMP process and the kind of pulp to be produced. It is therefore necessary to charge neutralizing alkali before or in the refiner. It is of course possible to do so before the PREX screw, but may require more alkali and more acid to the re-circulated leaching liquor.
  • the charging of the alkali is at the point where the wood material expands after the PREX screw. It will give some time for the alkali to be reasonably well distributed before the wood material enters the refiner. Other charge points can of course be considered.
  • the withdrawn leaching liquor goes to NPE removal according to known methods before it is re-circulated.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Paper (AREA)

Abstract

Un premier aspect de la présente invention concerne un procédé permettant de traiter des copeaux de bois provenant de bois tendre ou de bois dur, ou d'un mélange des deux, afin de réduire les éléments qui ne font pas partie du traitement et/ou des substances qui perturbent le processus organique dans un processus de réduction en pâte mécanique ou dans un processus de réduction en pâte chimico-mécanique; lequel procédé comprend les étapes consistant: a) à introduire des craquelures dans les copeaux ou à affiner les copeaux jusqu'à obtention d'une structure fibreuse grossière, de manière à réduire considérablement les voies de diffusion dans le bois; (b) à traiter les copeaux avec un liquide de lixiviation acide; c) à éliminer de manière exhaustive le liquide de lixiviation acide; et d) à ajuster le pH à un niveau convenant à l'affinage, de préférence un pH 4. Un second aspect de la présente invention concerne un système permettant de mettre en oeuvre le procédé susmentionné.
PCT/SE2003/001778 2002-12-04 2003-11-17 Procede et systeme de traitement de copeaux de bois WO2004050983A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
AU2003279671A AU2003279671A1 (en) 2002-12-04 2003-11-17 Method and system for treatment of wood chips
BR0316938-3A BR0316938A (pt) 2002-12-04 2003-11-17 Método para o tratamento de cavacos de madeira
SE0501175A SE528369C2 (sv) 2002-12-04 2005-05-25 Metod och system för behandling av träflis
FI20055267A FI20055267A (fi) 2002-12-04 2005-05-31 Menetelmä ja järjestelmä puuhakkeen käsittelemiseksi

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE0203594-7 2002-12-04
SE0203594A SE0203594D0 (sv) 2002-12-04 2002-12-04 Method for treatment of wood chips

Publications (1)

Publication Number Publication Date
WO2004050983A1 true WO2004050983A1 (fr) 2004-06-17

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PCT/SE2003/001778 WO2004050983A1 (fr) 2002-12-04 2003-11-17 Procede et systeme de traitement de copeaux de bois

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AU (1) AU2003279671A1 (fr)
BR (1) BR0316938A (fr)
FI (1) FI20055267A (fr)
SE (1) SE0203594D0 (fr)
WO (1) WO2004050983A1 (fr)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7771565B2 (en) 2006-02-21 2010-08-10 Packaging Corporation Of America Method of pre-treating woodchips prior to mechanical pulping
EP2348154A1 (fr) * 2010-01-22 2011-07-27 Andritz AG Procédé de fabrication de matériaux en bois
US8404355B2 (en) 2010-12-09 2013-03-26 Virdia Ltd Methods and systems for processing lignocellulosic materials and related compositions
US9115467B2 (en) 2010-08-01 2015-08-25 Virdia, Inc. Methods and systems for solvent purification
US9410216B2 (en) 2010-06-26 2016-08-09 Virdia, Inc. Sugar mixtures and methods for production and use thereof
US9476106B2 (en) 2010-06-28 2016-10-25 Virdia, Inc. Methods and systems for processing a sucrose crop and sugar mixtures
US9493851B2 (en) 2012-05-03 2016-11-15 Virdia, Inc. Methods for treating lignocellulosic materials
US9512495B2 (en) 2011-04-07 2016-12-06 Virdia, Inc. Lignocellulose conversion processes and products
US9617608B2 (en) 2011-10-10 2017-04-11 Virdia, Inc. Sugar compositions
US9631246B2 (en) 2012-05-03 2017-04-25 Virdia, Inc. Methods for treating lignocellulosic materials
US9663836B2 (en) 2010-09-02 2017-05-30 Virdia, Inc. Methods and systems for processing sugar mixtures and resultant compositions
US11078548B2 (en) 2015-01-07 2021-08-03 Virdia, Llc Method for producing xylitol by fermentation
US11091815B2 (en) 2015-05-27 2021-08-17 Virdia, Llc Integrated methods for treating lignocellulosic material
WO2024136742A1 (fr) * 2022-12-21 2024-06-27 Billerud Aktiebolag (Publ) Ht-ctmp formé à partir d'un mélange bois d'érable/bois de résineux et procédé de production d'un ht-ctmp à partir d'un mélange de bois d'érable/bois de résineux

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE458690B (sv) * 1986-11-06 1989-04-24 Sunds Defibrator Saett att framstaella mekanisk massa fraan lignocellulosahaltigt material i styckeform med en laengd i fiberriktningen av minst 200 mm

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE458690B (sv) * 1986-11-06 1989-04-24 Sunds Defibrator Saett att framstaella mekanisk massa fraan lignocellulosahaltigt material i styckeform med en laengd i fiberriktningen av minst 200 mm

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7943008B2 (en) 2006-02-21 2011-05-17 Packaging Corporation Of America Method of pre-treating woodchips prior to mechanical pulping
US7771565B2 (en) 2006-02-21 2010-08-10 Packaging Corporation Of America Method of pre-treating woodchips prior to mechanical pulping
EP2348154A1 (fr) * 2010-01-22 2011-07-27 Andritz AG Procédé de fabrication de matériaux en bois
WO2011088973A1 (fr) * 2010-01-22 2011-07-28 Andritz Ag Procédé pour fabriquer de la pâte mécanique
US9963673B2 (en) 2010-06-26 2018-05-08 Virdia, Inc. Sugar mixtures and methods for production and use thereof
US10752878B2 (en) 2010-06-26 2020-08-25 Virdia, Inc. Sugar mixtures and methods for production and use thereof
US9410216B2 (en) 2010-06-26 2016-08-09 Virdia, Inc. Sugar mixtures and methods for production and use thereof
US10760138B2 (en) 2010-06-28 2020-09-01 Virdia, Inc. Methods and systems for processing a sucrose crop and sugar mixtures
US9476106B2 (en) 2010-06-28 2016-10-25 Virdia, Inc. Methods and systems for processing a sucrose crop and sugar mixtures
US11242650B2 (en) 2010-08-01 2022-02-08 Virdia, Llc Methods and systems for solvent purification
US9115467B2 (en) 2010-08-01 2015-08-25 Virdia, Inc. Methods and systems for solvent purification
US10240217B2 (en) 2010-09-02 2019-03-26 Virdia, Inc. Methods and systems for processing sugar mixtures and resultant compositions
US9663836B2 (en) 2010-09-02 2017-05-30 Virdia, Inc. Methods and systems for processing sugar mixtures and resultant compositions
US8404355B2 (en) 2010-12-09 2013-03-26 Virdia Ltd Methods and systems for processing lignocellulosic materials and related compositions
US9512495B2 (en) 2011-04-07 2016-12-06 Virdia, Inc. Lignocellulose conversion processes and products
US11667981B2 (en) 2011-04-07 2023-06-06 Virdia, Llc Lignocellulosic conversion processes and products
US10876178B2 (en) 2011-04-07 2020-12-29 Virdia, Inc. Lignocellulosic conversion processes and products
US10041138B1 (en) 2011-10-10 2018-08-07 Virdia, Inc. Sugar compositions
US9976194B2 (en) 2011-10-10 2018-05-22 Virdia, Inc. Sugar compositions
US9845514B2 (en) 2011-10-10 2017-12-19 Virdia, Inc. Sugar compositions
US9617608B2 (en) 2011-10-10 2017-04-11 Virdia, Inc. Sugar compositions
US9493851B2 (en) 2012-05-03 2016-11-15 Virdia, Inc. Methods for treating lignocellulosic materials
US9783861B2 (en) 2012-05-03 2017-10-10 Virdia, Inc. Methods for treating lignocellulosic materials
US9650687B2 (en) 2012-05-03 2017-05-16 Virdia, Inc. Methods for treating lignocellulosic materials
US11053558B2 (en) 2012-05-03 2021-07-06 Virdia, Llc Methods for treating lignocellulosic materials
US9631246B2 (en) 2012-05-03 2017-04-25 Virdia, Inc. Methods for treating lignocellulosic materials
US11965220B2 (en) 2012-05-03 2024-04-23 Virdia, Llc Methods for treating lignocellulosic materials
US11078548B2 (en) 2015-01-07 2021-08-03 Virdia, Llc Method for producing xylitol by fermentation
US11091815B2 (en) 2015-05-27 2021-08-17 Virdia, Llc Integrated methods for treating lignocellulosic material
WO2024136742A1 (fr) * 2022-12-21 2024-06-27 Billerud Aktiebolag (Publ) Ht-ctmp formé à partir d'un mélange bois d'érable/bois de résineux et procédé de production d'un ht-ctmp à partir d'un mélange de bois d'érable/bois de résineux

Also Published As

Publication number Publication date
AU2003279671A1 (en) 2004-06-23
FI20055267A (fi) 2005-05-31
BR0316938A (pt) 2005-10-18
SE0203594D0 (sv) 2002-12-04

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