WO2000052256A1 - Feed preconditioning for chemical pulping - Google Patents
Feed preconditioning for chemical pulping Download PDFInfo
- Publication number
- WO2000052256A1 WO2000052256A1 PCT/US2000/004640 US0004640W WO0052256A1 WO 2000052256 A1 WO2000052256 A1 WO 2000052256A1 US 0004640 W US0004640 W US 0004640W WO 0052256 A1 WO0052256 A1 WO 0052256A1
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- WO
- WIPO (PCT)
- Prior art keywords
- chemical
- compression
- feed
- compression device
- introducing
- Prior art date
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Classifications
-
- 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
- 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
-
- 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
- D21C1/10—Physical methods for facilitating impregnation
Definitions
- the present invention relates to so-called "chemical pulping" of lignocellulosic feed material and in particular, to method and apparatus for improving the yield of chemical pulping.
- chemical pulping should be understood in the same sense as that used in the art, namely, to processes such as the Kraft, soda, soda AQ, Kraft AQ, sulphite, bisulfite, and other similar processes, whereby chemical reagents remove the lignin from the fiber structure of the feed material.
- processes such as the Kraft, soda, soda AQ, Kraft AQ, sulphite, bisulfite, and other similar processes, whereby chemical reagents remove the lignin from the fiber structure of the feed material.
- Kraft process For convenience, the present specification will focus on the Kraft process, but it will be understood by those familiar with this field of technology, thatthe concepts and features described and claimed herein, can readily be incorporated into the other types of chemical pulping processes.
- Chemical pulping has long been used in connection with the paper making industry. Moreover, perhaps 90% of all better grade papers used throughout the world, are made predominantly of chemical pulp. For this reason, it can well be appreciated that any improvements by which the yield is increased, would have very favorable economic and environmental consequences
- thermo-mechanical pulping In general, chemical pulping processes rely on the release of wood fibers by dissolution of the lignin which binds the fibers together. Because lignin and other non-cellulosic portions of the wood chips are removed in the process, chemical pulping processes typically provide yields of only 40-50% based on the dried chips, which is considerably less than so-called thermo-mechanical pulping (TMP), implemented in rotating disc refiners.
- TMP thermo-mechanical pulping
- U.S. Patent 4,869,783 discloses one technique for improving the yield of the chemical pulp process, whereby wood chips are partially defiberized in a high compression screw device associated with the feed end of the pulping process.
- the fibers in the chips are substantially separated from one another but sufficient inter fiber bonding is maintained to preserve chip integrity and thereby provide chips having an open porous fibrous network.
- the chips are subjected to chemical pulping to remove a majority of the lignin in the chips.
- highly compressing the chips in the feed portion of the pulping process would indeed appear to improve the bleached yield considerably (e.g., from about 45% to 50% on a comparative basis) with the pulp brightness also generally showing improvement, the strength properties of the pulp deteriorate significantly.
- the present inventor believes that the strength deterioration of the fibers is the main reason why the high compression of feed chips as described in the '783 patent has not seen commercial fruition notwithstanding the impressive data on improved yield and brightness relative to conventional processes. Specifically, it is believed that the loss in strength arises from the shattering and fracturing of fibers prior to feeding the chemical pulp digester. The process described in International App. No.
- PCT/US98/1 4710 published 1 8 February, 1 999, and entitled, "Method of Pretreating Lignocellulose Fiber-Containing Material” overcomes the significant strength deterioration associated with the process described in the '783 patent, by preceding the high compression of the chips with a conditioning step, whereby the chips are exposed to elevated temperature and pressure, preferably in an environment of saturated steam with no pressure barrier between the conditioning step and the compression zone.
- the conditioning of the chips prior to high compression results in considerably less brittle fracture and therefore a larger percentage of the original fiber retains acceptable size and strength during pulping and bleaching, rather than being washed away as fines for disposal or going forward with the fiber to the digester.
- Both of these feed end techniques require high mechanical compression (at a ratio of at least 3 or 4 to 1 ) before the feed material is introduced into the chemical digestion and recovery system of the plant.
- this compression will be referred to as
- the main aspect of the present invention is based on introducing process fluid into the compressive pretreatment stage, in an environment of elevated temperature and pressure, thereby initiating significant chemical pulping action on the chips at a point farther upstream than was previously known.
- this process fluid includes recycled process reagents drawn from process lines farther downstream.
- some of this process fluid is extracted as pressate during compression of the chips, and the pressate is reintroduced downstream, into the plant's recovery system. Therefore, there is no net increase in the fluid handling or chemistry requirements of the pulping equipment, the bleaching plant, and the black liquor recovery plant.
- the process fluid introduced upstream of the high compression device can be one or more of (a) steam (b) recirculated black liquor of any concentration, (c) recirculated white liquor of any concentration, (d) a vapor phase extract from the digester, (e) an externally supplied liquor including sulphite, NaOH, Na 2 S, etc., or (f) a combination thereof, e.g., vapor phase from the digester plus steam.
- the combination of high temperature, high pressure, and high compression achieves chemical impregnation into destructured chips upstream of the digester, to a far superior degree than was previously possible.
- the feed material is delivered under pressure to a compression device which has a variable speed motor such that the duration of exposure of the chips can be controlled therein.
- the chips experience an initial processing of consolidation and extraction of fluids through the walls of the compression device into a pressurized collar or flash tank. Thereafter the material is further consolidated at a high compression in the ratio of at least 3 to 1 and up to 8 to 1 or more, before discharge.
- the relative duration of the exposure of the material as between the consolidation phase and the high compression phase can be pre-established by, for example, the relative screw shaft lengths and wall characteristics defining these regions.
- the total travel time of the material in the compression device may range from a few seconds to more than a minute, with generally 50%-80% of the travel time associated with consolidation, and 20%-50% of the time associated with compression above a ratio of about 3 to 1 . In this manner, steam and chemicals can penetrate into the chips during partial defibration, during the initial consolidation phase, even prior to the continuing defibration in the high compression, plug portion of the device.
- the various aspects of the present invention can thus be defined according to the following implementations.
- the improvement comprises introducing a portion of a process fluid into the fibrous material, before the material is mechanically compressed.
- the improvement comprises exposing the material to an environment of pressure above 30 psi and a temperature above 1 20°C before and during the mechanical compression, and in this environment, contacting the material with a chemical liquor or vapor which initiates dissolution of the lignin from the fiber in the material.
- the improvement comprises exposing the material to an environment of saturated steam at a pressure above 30 psi before the mechanical compression. During the compression of the material, a pressate containing wood extractives is produced, and the pressate is introduced into the recovery system downstream of the mechanical compression.
- the invention is directed to a modification of the feed end of a system for chemical pulping of lignocellulosic feed material.
- a conditioning chamber has an inlet for receiving feed material, and means for exposing the feed material to elevated temperature and pressure for a target time period of exposure.
- a compression device maintained at elevated temperature and pressure, receives the conditioned feed material, consolidates the conditioned feed material including removal of extractives, compresses the conditioned material at a ratio of at least 3/1 , and discharges the compressed material into a feeder for the chemical digester.
- the exposure time period in the conditioning chamber, and the travel time period in the compression device are both adjustable.
- the conditioning chamber is preferably a variable speed transfer conveyor pressurized at a pressure above 30 psi with saturated steam
- the compression device is preferably a variable speed high compression screw pressurized with saturated steam at a pressure above 30 psi.
- Figure 1 is a schematic of the front end of a conventional Kraft chemical pulping plant with continuous vertical digester, with the feed portion backfit with a first embodiment of the invention including inclined impregnator;
- Figure 2 is a schematic flow diagram of a Kraft chemical pulping plant including compressive pretreatment according to the invention, and downstream processes including digesting, washing, optional oxygen delignification, bleaching, and liquor recovery;
- Figure 3 is a schematic of a variation of the invention as shown in Figure 1 , as would be implemented in a new plant with continuous vertical digester;
- Figure 4 is a schematic of a second embodiment of the invention including an inclined impregnator, in conjunction with a conventional continuous inclined digester
- Figure 5 is a schematic of a variation of the embodiment shown in Figure 4, wherein the high compression device discharges directly into the vapor phase region of an inclined continuous digester;
- Figure 6 is a schematic of a third embodiment, whereby the invention is used in conjunction with a batch digester
- Figure 7 is a schematic of a third embodiment, whereby the invention including impregnator is used in conjunction with a batch digester
- Figure 8 is a schematic of a fourth embodiment, in which the compression device discharges directly into a vertical impregnator situated within the inlet to a vertical digester;
- Figure 9 is a longitudinal section view of a first embodiment of a high compression device for implementing the present invention
- Figure 10 is a longitudinal section view of a second embodiment of a high compression device adapted for use with the present invention.
- Figure 1 1 is an electron micrograph illustrating the internal cross section of partially defibrated softwood chips using pressurized inlet conditions followed by high mechanical compression;
- Figure 1 2 is an electron micrograph illustrating the internal cross section of partially defibrated softwood chips using atmospheric inlet conditions followed by high mechanical compression.
- Figure 1 is schematic of one possible hardware implementation of the present invention.
- Figure 1 shows how the compressive pretreatment disclosed in International App. PCT/US98/1 4710, can be implemented in a commonly known vertical continuous digester system 10 such as the Kamyr type digester supplied by Ahlstrom Machinery
- the compressive pretreatment portion 1 2 according to the invention is shown in phantom.
- Wood chips are deposited in an atmospheric chip bin 14 and delivered via a chip metering valve 1 6 with pressurized discharge, to a horizontal presteaming conveyor 1 8. The pressure therein is below
- a pressurized conveying screw 20 having an inlet intersecting the vertical drop leg 22, exposes the chips to an environment of saturated steam, at a higher pressure, in the range of 30 - 1 50 psi or more, depending on the optimization of process conditions.
- This pressurized conveyor 20 is driven by a variable speed motor 24 such that the travel time through the conveyor can be controlled as an independent variable.
- the conditioned chips are then introduced via feed column 26 into a specially modified MSD Pressafiner or RT Pressafiner (available from Andritz Inc., Muncy, PA) with a pressurized inlet or similar compression device 28 which destructures the fibers and at the same time presses out liquid 30 and drives out air that may be present naturally or otherwise introduced, as will be described below. Therefore, the chips upon emerging from the discharge 32 of the compression device are receptive to the rapid and deep take-up of fluids
- an inclined wet impregnator/conveyor 34 (such as is available from Andritz Inc. as Model 60/30) is provided extending from the discharge of the compression device, back to the drop leg 22. All or some of the impregnator preferably contains process liquid, most commonly recirculated black liquor , in the case of Kraft pulping.
- One suitable compression device 28 shown in Figure 9 has a variable speed motor 36, an inlet section 38 in which the screw core or shaft 46 has a substantially uniform diameter, a consolidation or extraction section 42, through which the screw core gradually increases in diameter, forming an annulus of decreasing flow cross-section along the substantially cylindrical, perforated wall 44, followed by a plug section 46 which typically has a substantially cylindrical core without screw flights, and preferably includes adjustability 48 of the flow cross- section and/or flow restrictor elements.
- the screw flight outer diameter 50 remains substantially constant and the flights are not interrupted, but other variations having the desire functionality according to the present invention, are within the ordinary skill of practitioners in this field of technology.
- the pressurized conveyor 20 is shown in section, feeding into a Topwinder type forced feeder 52 (available from Andritz Inc.) which is particularly effective for feeding non-chip material such as bamboo, bagasse, sawdust, and similar materials, which cannot be introduced at a sufficient volummetric rate by relying on gravity alone.
- the enhanced feeder 52 for the inlet to the compression device is optional.
- the material after entering the inlet 38, flows to the right, is consolidated as it passes through the reducing cross-section. Because the material is at the same elevated pressure conditions as in the pressurized conveyor 20, a pressurized jacket 54 surrounds the perforated wall 44 in the consolidation section 42. Fluid is extracted, either by flashing or simply by draining and is ultimately withdrawn through drain pipes 30 or valve controlled flashing.
- the material undergoes a particular travel time in a consolidation along distance D1 , where consolidation and extraction is occurring at an increasing rate, in distinction from the travel time along distance D2, where a plug is formed and the material experiences very high compression i.e., a ratio above 3/1 , preferably in the range 4/1 to 8/1 , and even more especially
- reagents are introduced anywhere upstream of the device discharge 32, for example, at , in the pressurized conveyor, or 3 in the Topwinder feeder or at the inlet to the compression device, the initial stages of lignin dissolution can begin to a significantly greater extent than is possible in a compression screw device that has a substantially atmospheric environment, because the fibers are more open and reactive.
- Reagents added upstream can also be used to initiate milder reactions prior to cooking in the digesters, such as subjecting the chips to black liquor with low hydroxyl content and high hydrosulfide content in the case of kraft pulping.
- FIG. 10 Another compression screw device 28' usable with the present invention, is shown in Figure 10.
- the structural aspects of this device are disclosed and described in international application PCT/US92/00939 (published as WO92/1 371 0) .
- the additional modifications include a variable speed drive, pressurized inlet and high compression ratio.
- the respective retention times in region D1 where the material is consolidated under steam pressure, and the retention time for D2, where the material is in the form of a compressed chip plug, are closely analogous to those described with respect to Figure 9.
- the device of Figure 1 0 shows an interrupted flight section 56 where the compressed material can be "worked" to some extent thereby increasing the defibering action as well as producing further pressate, before passing through the discharge section.
- a high pressure feeder column 58 with return pump 70 following the drop leg 22 delivers a slurry of chips in black liquor or an alternative liquor, at a pressure of 5 to 1 0 bar, along line 60 to the inlet 62 at the top of the continuous vertical digester 64.
- a black liquor liquid level 66 it is common in the conventional portion of the system represented in Figure 1 , for a black liquor liquid level 66 to be present in the drop leg immediately above the inlet 68 to the high pressure feeder column 58.
- the inlet 62 at the top of the digester includes a pressurized drainer 72 or top separator which extracts much of the liquid in the slurry for return via pump 70 to the high pressure feeder 58.
- the separated but wet chips drop into the digester proper for chemical pulping action with liquor of increasing intensity as the chips move downwardly through the cooking zone of the digester column.
- the cooking conditions of temperature, pressure and possibly reagent concentration in digester 64 can be reduced to achieve a predetermined degree of lignin dissolution. This in turn will result in an increase in yield due to less degradation of the cellulose and hemicellulose components. Conversely, the cooking conditions can be maintained, however, with a reduction in cook time and concomitant increase in production capacity.
- process fluid in the compressive pretreatment equipment in accordance with the invention, particularly into the pressurized conditioning chamber 20 at ., and/or via ⁇ 2 at the discharge 32 of the compressive destructuring device 28, significant benefits can be achieved.
- the process begins with the atmospheric presteaming bin 14 as shown in Figure 1 and is followed by the compressive pretreatment stage 1 2 which, in the preferred embodiment, comprises pressurized conditioning and compressive destructuring of the chips.
- the pretreated chips are then introduced into the chemical pulping equipment (i.e., digester 64), and thereafter washed 74.
- the "cooking" in the digester is performed with increasingly strong concentrations of white liquor via line(s) 76.
- a higher temperature black liquor is first introduced prior to the addition of white liquor.
- the process liquid After removal of the lignin to the desired Kappa value, the process liquid has darkened considerably and is thereafter referred to as black liquor.
- the black liquor is washed from the chips and the diluted black liquor is passed through a drain line 78 to the black liquor seal tank 80.
- the washed chips are then sent to a bleaching plant 82 where the chips are exposed to successive stages of chlorination, extraction and chlorine dioxide bleaching, thereby producing essentially bleached white pulp as the desired end product of the process.
- Several variations of the bleaching process are also practiced including oxygen pre-delignification, ozone pre-treatment, extraction with oxygen and peroxide addition (EOP), chlorine substitution with chlorine dioxide, etc.
- no elemental chlorine is used (ECF) and occasionally no chlorine of any type is used (TCF).
- the liquor from the black liquor seal tank eventually passes through an evaporator array 84 and the concentrated black liquor, containing approximately 65% solids, is delivered to a recovery boiler 86.
- a recovery boiler 86 For simplification in Figure 2, optional black liquor oxidation treatment is not shown.
- the lignin, wood extractives, and some hemicellulosic material are burned, producing gases and some particulates which may require scrubbing (i.e., electrostatic precipitator) before discharge through a stack.
- the smelt consisting essentially of inorganic chemicals, passes through a chemical recovery process 88. Upon exiting the chemical recovery process as regenerated white liquor, the liquid can be returned for introduction into the digester or similar chemical pulping unit.
- Points B1 , B2, B3 and B4 represent various locations in which the used liquor is processed and recovered in the kraft process.
- Point W represents a line containing white liquor.
- Point V represents a vapor phase of cooking (white) liquor that often is deliberately maintained near the inlet of the digester.
- a flow of one or more black liquor B, white liquor W, or vapor phase V from the digester can be introduced from a downstream line, into the compressive pretreatment stage 1 2.
- steam S or external liquor L with chemical reagent can be similarly introduced in the compressive pretreatment stage.
- line ⁇ represents the introduction of any one or combination of the process fluids B, W, V,
- Fluid line ⁇ 2 represents a different point of introduction of the same or different one or combination of process fluids B, W, V, S or L, at the discharge 32 of the high compression device (e.g., Pressafiner) .
- V vapor phase chemicals
- recycled black liquor B or low alkalinity white liquor W
- the chips are not damaged during pretreatment and can be subjected to conventional cooking conditions without deterioration in the yield, strength, or brightness of the fibers.
- the chips can be cooked to low Kappa number values, or at least to the same values as conventionally cooked chips. This is of particular significance with mills which use TCF bleaching, in which a low initial Kappa number is necessary. Inspection of chips which have been conditioned under high pressure and then highly compressed, reveals an open chip structure in which the chips are quite pliable when rolled between the figures, without internal fracturing of the fiber structure.
- conventional yield can be increased in a first increment by the use of pressurized conditioning immediately preceding the compressive destructuring. This results from better penetration of chemicals between the fibers at the discharge of the compression device.
- a further increment of yield and/or efficiency can be achieved by a reduction in the severity of cooking (via decreased temperature, pressure, alkali concentration) to achieve a given Kappa value.
- the partially defibrated chip structure is more rigid the material can tolerate extensive cooking to lower Kappa values without loss in pulp strength.
- the plant can be optimized as between utilization of the conventional size and footprint of digesting equipment to achieve a higher than standard yield, or else for a given desired throughput, the size and/or footprint of the equipment can be reduced.
- smaller digester units can be utilized, to achieve current levels of throughput.
- FIG 3 illustrates an alternative system configuration 100, to that of Figure 1 .
- the rotary valve 1 6 with pressurized discharge deposits chips directly into the pressurized conveyor 20.
- a stream of process fluid ⁇ is introduced near the inlet to the pressurized conveyor.
- the pressurized conveyor discharges immediately into the inlet of the compression device 28, which in turn discharges into a conventional drop leg 22' associated with feeding into the high pressure feeder column 58.
- this configuration uses only one (pressurized) conveyor 20 and is thus more compact.
- Process liquid along line ⁇ 2 can De introduced as a vapor or liquid at the discharge of the compression device 28.
- FIG 4 shows another system embodiment 200 of the invention, as used in conjunction with an M&D continuous digester 202 (available from Andritz Inc.), or other digester operating on similar principles.
- these digesters have buckets or the like which move along line 204 whereby the material is introduced into a vapor cooking phase in the buckets in the upper portion 206, the buckets travel downwardly through a liquid phase 208 of the cooking fluid, and rise upwardly through the vapor phase again, for discharge through a rotary valve 210 with pressurized inlet.
- the atmospheric chip bin 1 4 delivers chips through a rotary valve 1 6 with pressurized discharge, into a pressurized conveyor 20, which in turn is followed by a compression device 28.
- the compression device discharges into an inclined wet conveyor or impregnator 34 at atmospheric conditions.
- the discharge from the impregnator is horizontally conveyed to a rotary valve 210 with pressurized discharge, which in turn feeds the pressurized vapor phase inlet of the digester in a conventional manner.
- Process fluid can as in the previous embodiments, be introduced at ⁇ ⁇ 2 , and/or ⁇ 3 .
- Figure 5 shows alternative configuration 300 for use with an M&D type digester 202, wherein the chips are conveyed from the atmospheric chip bin 14 through a rotary valve 1 6 with pressurized discharge, into a pressurized conveyor 20 which in turn feeds the compression device 28.
- the discharge 32 of the compression device is directly exposed to the vapor phase 206 of the cooking fluid in the upper, inlet portion of the digester.
- Figure 6 shows a feed system configuration 400 that can be utilized upstream of the feed chute 402 to batch type digester. Chips from the atmospheric bin 14 are fed through the rotary valve 1 6 into a pressurized conveyor 20 and then through the chip compression device 28, which in turn discharges to a transfer conveyor 404 for charging into the batch digester.
- Figure 7 shows a further modification 500 wherein the compression device 28 discharges into an inclined impregnator 34 prior to transfer for charging at 402 into the batch digester. It can be seen in both Figures 6 and 7 that process flow lines ⁇ and/or ⁇ 2 can be effectively utilized, as with the previously-described embodiments.
- Figure 8 shows yet another system implementation 600, whereby the chip material from the feed bin 14 is conditioned at high pressure at 20, then introduced to the compression device 28, which provides the additional function of the feeder device for the vertical digester 602.
- the compression device 28 discharges into a vertical impregnator 604 where the compressed chips, upon expansion as they discharge from the compressing unit at 32, are exposed to the liquid 606 and are thereby impregnated immediately as they are conveyed upwardly by screw 608 before dropping down into the main region 610 of the vertical digester.
- the preferred implementation includes a variable speed drive 24 on the pressurized conveyor 20, thereby providing control of the exposure of the chips to the elevated temperature and pressure conditions, for a controlled time period, preferably in the range of 10-1 800 seconds.
- the compression device 28 in all embodiments preferably includes a variable speed motor 36 to provide an independent control on the time interval during which the chips are processed in the device.
- a variable speed motor 36 to provide an independent control on the time interval during which the chips are processed in the device.
- a range of 5-1 5 seconds would be especially beneficial where a process fluid line such as jf 3 of Figure 1 , is connected to the inlet 38 of compression device (or at any point upstream of the discharge end 32) .
- the time period of exposure can be controlled, at one or both of the conditioning chamber 20 or compression device 28.
- the invention can be optimized by continually measuring and controlling the relative mixing of process fluids or with other fluid such as L or S chemical reagents such as B, W, or V for delivery via any of lines ⁇ , ⁇ , or ⁇
- the pressurized environment as distinct from the atmospheric pressure in the conveyor and compression device as is typical in conventional atmospheric inlet screw devices, not only opens the chips up for more efficient lignin removal, but importantly maintains the elongation of the chips and minimizes brittle fractures and shattering. This advantage contributes significantly to the ability of the present invention, to permit cooking to desired Kappa number levels without loss in pulp strength properties.
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Abstract
Description
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Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA002363158A CA2363158A1 (en) | 1999-03-02 | 2000-02-24 | Feed preconditioning for chemical pulping |
SE0102865A SE0102865L (en) | 1999-03-02 | 2001-08-29 | Feed preconditioning for chemical pulping |
FI20011738A FI20011738A (en) | 1999-03-02 | 2001-08-31 | Pre-processing of the feed for chemical pulping |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US26076199A | 1999-03-02 | 1999-03-02 | |
US09/260,761 | 1999-03-02 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2000052256A1 true WO2000052256A1 (en) | 2000-09-08 |
Family
ID=22990514
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2000/004640 WO2000052256A1 (en) | 1999-03-02 | 2000-02-24 | Feed preconditioning for chemical pulping |
Country Status (4)
Country | Link |
---|---|
CA (1) | CA2363158A1 (en) |
FI (1) | FI20011738A (en) |
SE (1) | SE0102865L (en) |
WO (1) | WO2000052256A1 (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7713381B2 (en) * | 2004-07-08 | 2010-05-11 | Andritz Inc. | TMP refining of destructured chips |
CN101914863A (en) * | 2010-07-28 | 2010-12-15 | 商丘市丰源纸业科技有限公司 | Process for extracting papermaking black liquor by steaming |
EP2336344A1 (en) * | 2009-12-21 | 2011-06-22 | Sekab E-Technology AB | Pre-treatment of cellulosic material |
US10450701B2 (en) * | 2014-10-15 | 2019-10-22 | Licella Pty Ltd | Pulping liquors and uses thereof |
WO2021141712A1 (en) * | 2020-01-09 | 2021-07-15 | Westrock Mwv, Llc | Method for manufacturing bleached pulp from a feedstock comprising recycled paper |
Citations (4)
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WO1992011409A1 (en) * | 1990-12-17 | 1992-07-09 | Tag Pulp Industries S.A. | Method for supplying pressurized continuous digesters to obtain cellulose pulp |
WO1997028305A1 (en) * | 1996-01-31 | 1997-08-07 | Sunds Defibrator Woodhandling Oy | Process and apparatus for treatment of fibrous raw material |
WO1998050623A1 (en) * | 1997-05-05 | 1998-11-12 | Sunds Defibrator Industries Ab | Apparatus for feeding and refining lignocellulosic material |
WO1999007935A1 (en) * | 1997-08-08 | 1999-02-18 | Andritz Inc. | Method of pretreating lignocellulose fiber-containing material for the pulp making process |
-
2000
- 2000-02-24 WO PCT/US2000/004640 patent/WO2000052256A1/en active Application Filing
- 2000-02-24 CA CA002363158A patent/CA2363158A1/en not_active Abandoned
-
2001
- 2001-08-29 SE SE0102865A patent/SE0102865L/en not_active Application Discontinuation
- 2001-08-31 FI FI20011738A patent/FI20011738A/en unknown
Patent Citations (4)
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WO1992011409A1 (en) * | 1990-12-17 | 1992-07-09 | Tag Pulp Industries S.A. | Method for supplying pressurized continuous digesters to obtain cellulose pulp |
WO1997028305A1 (en) * | 1996-01-31 | 1997-08-07 | Sunds Defibrator Woodhandling Oy | Process and apparatus for treatment of fibrous raw material |
WO1998050623A1 (en) * | 1997-05-05 | 1998-11-12 | Sunds Defibrator Industries Ab | Apparatus for feeding and refining lignocellulosic material |
WO1999007935A1 (en) * | 1997-08-08 | 1999-02-18 | Andritz Inc. | Method of pretreating lignocellulose fiber-containing material for the pulp making process |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7713381B2 (en) * | 2004-07-08 | 2010-05-11 | Andritz Inc. | TMP refining of destructured chips |
CN102666865B (en) * | 2009-12-21 | 2015-04-08 | 瑞典乙醇化工技术有限公司 | Pre-treatment of cellulosic material |
EP2336344A1 (en) * | 2009-12-21 | 2011-06-22 | Sekab E-Technology AB | Pre-treatment of cellulosic material |
WO2011080131A3 (en) * | 2009-12-21 | 2011-09-29 | Sekab E-Technology Ab | Pre-treatment of cellulosic material |
CN102666865A (en) * | 2009-12-21 | 2012-09-12 | 瑞典乙醇化工技术有限公司 | Pre-treatment of cellulosic material |
US8834633B2 (en) | 2009-12-21 | 2014-09-16 | Sekab E-Technology Ab | Pre-treatment of cellulosic material |
AP3319A (en) * | 2009-12-21 | 2015-06-30 | Sekab E Technology Ab | Pre-treatment of cellulosic material |
US9528129B2 (en) | 2009-12-21 | 2016-12-27 | Sekab E-Technology Ab | Pre-treatment of cellulosic material |
CN101914863A (en) * | 2010-07-28 | 2010-12-15 | 商丘市丰源纸业科技有限公司 | Process for extracting papermaking black liquor by steaming |
US10450701B2 (en) * | 2014-10-15 | 2019-10-22 | Licella Pty Ltd | Pulping liquors and uses thereof |
US11306435B2 (en) | 2014-10-15 | 2022-04-19 | Licella Pty Ltd. | Integrated Kraft pulp mill and thermochemical conversion system |
US11834783B2 (en) | 2014-10-15 | 2023-12-05 | Canfor Pulp Ltd. | Integrated kraft pulp mill and thermochemical conversion system |
WO2021141712A1 (en) * | 2020-01-09 | 2021-07-15 | Westrock Mwv, Llc | Method for manufacturing bleached pulp from a feedstock comprising recycled paper |
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FI20011738A (en) | 2001-08-31 |
SE0102865D0 (en) | 2001-08-29 |
CA2363158A1 (en) | 2000-09-08 |
SE0102865L (en) | 2001-08-29 |
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