AU3256101A - Pulping process - Google Patents
Pulping process Download PDFInfo
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- AU3256101A AU3256101A AU32561/01A AU3256101A AU3256101A AU 3256101 A AU3256101 A AU 3256101A AU 32561/01 A AU32561/01 A AU 32561/01A AU 3256101 A AU3256101 A AU 3256101A AU 3256101 A AU3256101 A AU 3256101A
- Authority
- AU
- Australia
- Prior art keywords
- gas
- chlorine dioxide
- containing material
- process according
- lignocellulose containing
- Prior art date
- Legal status (The legal status 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 status listed.)
- Granted
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- 238000000034 method Methods 0.000 title claims description 63
- 230000008569 process Effects 0.000 title claims description 59
- 238000004537 pulping Methods 0.000 title claims description 24
- OSVXSBDYLRYLIG-UHFFFAOYSA-N dioxidochlorine(.) Chemical compound O=Cl=O OSVXSBDYLRYLIG-UHFFFAOYSA-N 0.000 claims description 92
- 239000007789 gas Substances 0.000 claims description 55
- 239000004155 Chlorine dioxide Substances 0.000 claims description 46
- 235000019398 chlorine dioxide Nutrition 0.000 claims description 46
- 239000000463 material Substances 0.000 claims description 43
- 238000011282 treatment Methods 0.000 claims description 18
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims description 14
- 229920005610 lignin Polymers 0.000 claims description 10
- 239000000203 mixture Substances 0.000 claims description 8
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 claims description 6
- 239000000460 chlorine Substances 0.000 claims description 6
- 150000001875 compounds Chemical class 0.000 claims description 5
- 125000004430 oxygen atom Chemical group O* 0.000 claims description 5
- 238000010025 steaming Methods 0.000 claims description 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 4
- 239000004291 sulphur dioxide Substances 0.000 claims description 3
- 235000010269 sulphur dioxide Nutrition 0.000 claims description 3
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 2
- 239000001569 carbon dioxide Substances 0.000 claims description 2
- 239000002023 wood Substances 0.000 description 18
- 238000007670 refining Methods 0.000 description 12
- 229920001131 Pulp (paper) Polymers 0.000 description 8
- 238000009792 diffusion process Methods 0.000 description 7
- 239000007864 aqueous solution Substances 0.000 description 6
- 239000000835 fiber Substances 0.000 description 6
- 230000009467 reduction Effects 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 238000000227 grinding Methods 0.000 description 5
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 4
- 229910052801 chlorine Inorganic materials 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 238000005265 energy consumption Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 229920002678 cellulose Polymers 0.000 description 2
- 239000001913 cellulose Substances 0.000 description 2
- 238000010411 cooking Methods 0.000 description 2
- 239000012634 fragment Substances 0.000 description 2
- 230000001771 impaired effect Effects 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 238000012216 screening Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- MGWGWNFMUOTEHG-UHFFFAOYSA-N 4-(3,5-dimethylphenyl)-1,3-thiazol-2-amine Chemical compound CC1=CC(C)=CC(C=2N=C(N)SC=2)=C1 MGWGWNFMUOTEHG-UHFFFAOYSA-N 0.000 description 1
- 241000609240 Ambelania acida Species 0.000 description 1
- 235000017166 Bambusa arundinacea Nutrition 0.000 description 1
- 235000017491 Bambusa tulda Nutrition 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 229920002488 Hemicellulose Polymers 0.000 description 1
- 244000082204 Phyllostachys viridis Species 0.000 description 1
- 235000015334 Phyllostachys viridis Nutrition 0.000 description 1
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical class [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 229920002522 Wood fibre Polymers 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000010905 bagasse Substances 0.000 description 1
- 239000011425 bamboo Substances 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 150000001720 carbohydrates Chemical class 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 239000013256 coordination polymer Substances 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 239000011121 hardwood Substances 0.000 description 1
- 239000002655 kraft paper Substances 0.000 description 1
- 239000012978 lignocellulosic material Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000010297 mechanical methods and process Methods 0.000 description 1
- 230000005226 mechanical processes and functions Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000005549 size reduction Methods 0.000 description 1
- UKLNMMHNWFDKNT-UHFFFAOYSA-M sodium chlorite Chemical compound [Na+].[O-]Cl=O UKLNMMHNWFDKNT-UHFFFAOYSA-M 0.000 description 1
- 229960002218 sodium chlorite Drugs 0.000 description 1
- 235000011121 sodium hydroxide Nutrition 0.000 description 1
- 229910052979 sodium sulfide Inorganic materials 0.000 description 1
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 1
- 239000011122 softwood Substances 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 239000010902 straw Substances 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-L sulfite Chemical compound [O-]S([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-L 0.000 description 1
- 229910021653 sulphate ion Inorganic materials 0.000 description 1
- 239000010875 treated wood Substances 0.000 description 1
- 239000010876 untreated wood Substances 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
- 239000000080 wetting agent Substances 0.000 description 1
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
- 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
Landscapes
- Paper (AREA)
- Polysaccharides And Polysaccharide Derivatives (AREA)
Description
WO 01/59203 PCT/SE01/00257 1 Pulpinq Process The present invention relates to a process for the removal of lignin from lignocellulose containing material comprising treating the lignocellulose containing material prior to a high-yield pulping process with a delignifying gas comprising gaseous 5 compounds comprising at least one oxygen atom. Background In high-yield processes, or mechanical pulping processes as they also are referred to, the objective is to disrupt the structure of the lignocellulosic containing material in fragments of variable dimensions by the use of mechanical treatment 10 optionally in the presence of chemicals. High-yield pulps are produced by grinding or refining of the lignocellulose containing material and thereby essentially all of the fibres constituents are retained in the pulp. High-yield pulping processes encompasses grinding, screening and refining 15 processes. In the grinding process, washed logs are forced against a rotating grinding disk to tear the lignocellulose containing material into small pieces which are then further processed by screening or refining to produce mechanical pulp. In the refining process, screened washed chips pass between rotating disks or a rotating and stationary disk to shred the lignocellulose containing material into pulp. The resultant pulp may then be 20 further refined, screened and cleaned to produce the desired mechanical pulp. One aspect of high-yield pulping is to rip or shred the lignocellulose containing material into fibres which consumes energy. This energy is measured as the power required to rotate the grindstone or the refiner disk(s). A significant portion of the total energy used in high-yield pulping process is 25 required to break or soften the lignin bonded to the cellulose and hemicellulose fibres. Weakening or breaking down the lignin structure prior to the grinding or refining process results in significant reductions in the power requirement to produce the finished high yield (mechanical) pulp. Energy, usually measured in terms of electrical power, is a major component in 30 the cost of producing high-yields pulps. Thus, the pulp production cost increases directly with the cost of energy. Therefore, one advantage of the present invention is to provide a pretreatment process that softens or breaks the lignin contained within the lignocellulose containing material resulting in a substantial reduction in the energy required to produce high yield 35 pulp. US 4172006 refers to the pretreatment of wood chips with oxygen prior to adding a cooking liquor.
WO 01/59203 PCT/SE01/00257 2 US 4750973 relates to a process for reducing carbohydrate losses in sulphate pulping of wood using sodium hydroxides and sodium sulfide, wherein the wood is pretreated in presence of water with oxygen gas and nitrogen oxides. GB 567774 discloses a process for the treatment of cellulosic raw material 5 where wood chips are contacted with a aqueous solution of a wetting agent prior to subjecting the chips to a solution containing sodium chlorite thereby using sufficient acid to insure the liberation of chlorine dioxide. WO 8908165 refers to a method for the pretreatment of wood chips with sulphur dioxide gas prior to alkaline deligification operations. 10 DE 1049220 discloses a method comprising subjecting wood chips to carbon acid before sulfite cooking. JP 49020241 refers to a pulping process comprising the steps of reacting chlorine dioxide or a mixture consisting of chlorine dioxide and chlorine with wood chips in the presence of water soluble cellulose derivatives and thereafter removing inter alia 15 the oxidised lignin by extraction. US 5474654 refers to a delignification process where chlorine dioxide gas is used on pulp obtained from pulping processes such as chemical kraft, sulfide or mechanical processes. Common to all prior art documents cited above is that the pretreatment is carried 20 out before a chemical pulping process. US 3591451 and US 3919041 disclose the use of gaseous chlorine dioxide subsequent a pretreatment step which may be either mechanical, chemical or a combination thereof. Summary of the invention 25 In accordance with the present invention it has surprisingly been found that a substantial reduction in the energy required to produce high yield pulp can be obtained by providing a process according to the claims. More specifically, the invention relates to a process for the removal of lignin from lignocellulose containing material comprising treating the lignocellulose containing material prior to a high-yield pulping process with a 30 delignifying gas, wherein the gas comprises gaseous compounds comprising at least one oxygen atom. Detailed description of the invention Suitable lignocellulose containing material used in the present invention can be any lignocellulose containing material derived from natural sources such as softwood, 35 hardwood, gum, straw, bagasse and/or bamboo. The physical state of the lignocellulose containing material is not critical, however, a physical state providing a large surface area is preferred that maximises penetration of the delignifying gas and optionally processing WO 01/59203 PCT/SE01/00257 3 chemicals. Suitably, the lignocellulose containing material is in the form of chips with a size which is governed by the process equipment and process parameters. Further advantages of the present invention are apparent from the specification. The lignocellulose containing material is suitably treated according to any 5 method known to the skilled artisan which renders the diffusion of the delignifying gas within the fibre source to the lignin more effective such as steaming and/or evacuation. According to the present invention the lignocellulosic material is treated with a delignifying gas comprising gaseous compounds comprising at least one oxygen atom. Suitably, the delignifying gas comprising chlorine dioxide, nitrogen oxides, carbon dioxide 10 or sulphur dioxide or mixtures thereof. Nitrogen oxides include nitrogen monoxide, nitrogen dioxide, polymeric oxides and double molecules thereof, e.g. N 2 0 4 or N 2 0 3 . The delignifying gas mixture is suitably a non-liquid containing gas. According to one preferred embodiment the delignifying gas comprises chlorine dioxide. The chlorine dioxide containing gas may contain other gases such as nitrogen, 15 oxygen, air or steam or mixtures thereof. The chlorine dioxide containing gas may also contain small amounts of chlorine, however, the gas is suitably substantially free from chlorine, preferably having less than 10% by volume, more preferably less than 1% by volume of chlorine. The use of a delignifying gas such as a gas comprising chlorine dioxide 20 overcomes several unsolved problems. Treatment of the lignocellulosic containing material with solutions containing for example chlorine dioxide is limited by the rate of chlorine dioxide diffusion through the solution to the fibre source followed by the diffusion of the chlorine dioxide within the fibre source to the lignin. The result is a slow delignification process that works primarily on the fibre source surface and an aqueous 25 effluent stream containing chlorine dioxide, dissolved fibre components and chlorides, which is difficult to treat in an environmentally correct manner. It has been found that a gas comprising chlorine dioxide does not have the diffusion barriers that limit the process when a solution is used. The gas passes rapidly and uniformly into the fibre source resulting in even delignification throughout the 30 material. Furthermore, there are no aqueous effluent streams. Preferably, the gas comprising chlorine dioxide is applied on lignocellulose containing material free from any surrounding aqueous solution. Preferably, the moisture content of the lignocellulose containing material is from about 30 weight % up to about 60 weight % based on oven dry material, more preferably from about 40 up to about 50 35 weight %. The chlorine dioxide containing gas employed in the present invention is suitably produced using a chlorine dioxide generation process as described in the US patens US WO 01/59203 PCT/SE01/00257 4 4770868, US 5091166, US 5091197 and US 5380517, which all are incorporated by reference. The concentration of chlorine dioxide in the gas is not critical for the invention. Thus, the lignocellulose containing material may be treated with substantially pure 5 chlorine dioxide gas. The upper limit of the amount of chorine dioxide, i.e. chlorine dioxide comprised in the gas mixture, is purely set by safety considerations. Suitable concentrations of chlorine dioxide comprised in the gas mixture are from about 0.05 up to about 100% by volume, more preferably from about 0.05 up to about 50 % by volume and most preferably from about I up to about 20 % by volume. 10 The gas comprising chlorine dioxide is generally applied in amounts which renders a reduction in the energy required for the production of pulp compared to a process where the lignocellulose containing material has not been subjected to chlorine dioxide prior to said high-yield process. Usually, increased applied amount of chlorine dioxide comprised in the gas (mixture) increases the degree of delignification. The charge 15 of chlorine dioxide is from about 0.5 kg/tonne up to about 300 kg active C1 2 per tonne of oven dry material, more preferably from about 2 kg up to about 100 kg active C1 2 per tonne oven dry material and most preferably from about 30 kg/tonne up to about 50 kg active Cl 2 per tonne oven dry material. The present invention may be performed at any location prior to high-yield 20 pulping processes, i.e. mechanical pulping processes. According to a preferred embodiment the treatment with the gas comprising gaseous compounds comprising at least one oxygen atom is carried out prior to a refining process, suitably prior to a first refining process. The lignocellulose containing material may be treated with the delignifying gas in 25 any type of equipment. For practical reasons the equipment should be gas tight. The treatment with the gas comprising chlorine dioxide may also be carried out in the same equipment (vessel) as is used for the subsequent pulping process. Suitably, the treatment is carried out in an equipment such as a vessel which is essentially free from an aqueous solution, i.e. the treatment is carried out in the absence 30 of aqueous solutions. By essentially free from an aqueous solution is meant that a minor amount aqueous solution can be present during the treatment with a gas comprising chlorine dioxide as long as the removal efficiency of lignin is not significantly impaired, i.e. as long as the overall diffusion (diffusion of the gas in respect of the totality of material treated) of the gas containing chlorine dioxide to the lignocellulose containing material is 35 not significantly impaired or as long as a reduction in the energy required for the production of high-yield pulp is obtained compared to a process where the lignocellulose WO 01/59203 5 PCT/SE01/00257 containing material has not been subjected to chlorine dioxide prior to said high-yield process. The delignifying gas such as a gas comprising chlorine dioxide is suitably admixed with the lignocellulose containing material in an equipment which is at any 5 suitable pressure including atmospheric, subatmospheric or superatmospheric pressures. Suitably, the treatment is carried out at a pressure ranging from about 10 kPa up to about 500 kPa, preferably from about 50 kPa up to about 250 kPa. The most preferred pressure ranges from about 80 kPa up to about 120 kPa. The temperature during the treatment according to the present invention is not 10 critical and can be carried out at surprisingly low temperatures including ambient temperatures. The upper temperature level in the treatment is set by economical and safety considerations. Temperatures may range from about 10 0 C up to about 400 *C, suitably from about 15 *C up to 200 *C, more preferably from 20 *C up to about 95 "C and most preferably from about 25 *C up to about 90 *C. Suitable temperature ranges are 15 also those obtained by combining any of the lower temperature level of above ranges with any of the higher temperature levels. According to one preferred embodiment of the present invention the lignocellulose containing material is pretreated prior to being subjected to the gas comprising chlorine dioxide. The pretreatment may be accomplished in the same 20 equipment used for the delignifying gas, yet, the pretreatment can also be performed in any suitable equipment located upstream the treatment with the delignifying gas. Suitably, the pretreatment includes various steaming and/or evacuation processes. The pretreatment is believed to open up the lattice structure of the lignocellulose containing material thereby improving the diffusion of the delignifying gas into the material. 25 High-yield or mechanical pulping processes are generally pulping processes where the yield typically is from about 70 up to about nearly 100% by weight based on total lignocellulose containing material. Commonly, high-yield pulping processes are referred to as stone groundwood (SGW), pressurised groundwood (PGW), refiner mechanical pulp (RMP) and modifications thereof, thermomechanical pulp (TMP), 30 chemithermomechanical pulp (CTMP) or chemimechanical pulp (CMP). The basic principle in high-yield pulping processes is to disrupt the wood structure in fragments of variable dimensions by the use of mechanical treatments optionally in conjunction with chemicals such as sulphite. Usually a refiner is used, where wood ships are fed between two metal disks, of which at least one disc is rotating, and the wood fibres are separated 35 by the action of grooves and bars located on the surface of the two disks. Obviously, energy usage is high in high-yield pulping processes, especially in TMP pulping processes.
WO 01/59203 6 PCT/SE01/00257 Thus, one advantage with the present invention is that by treating lignocellulose containing material prior to high-yield pulping processes the input of energy in said pulping processes can be significantly reduced. The process may be operated in either batch or continuous mode. 5 To further illustrate the invention the following examples are provided. All parts and percentages are by weight unless otherwise specified. Temperatures are in degrees Celsius. Example In this example the total energy consumption for refining untreated wood chips 10 and wood chips treated with chlorine dioxide containing gas prior to high yield pulping to specific Canadian Standard Freeness (CSF) levels was measured. Douglas Fir wood chips obtained from a commercial pulp supplier were used. The samples were pulled at random from the chip supply and were then mixed and separated into samples 1 and 2. There was no special handling, separation or 15 classification of the chips prior to the experiment. The chips of sample 1 were treated with the chlorine dioxide containing gas in a packed bed reactor with a gas containing approximately 3% to 5% chlorine dioxide on a volume basis. Approximately 20 grams of chlorine dioxide were used to treat 1 kg of wood chips. The resulting treated wood chips were then pre-steamed and mechanically refined to specific Canadian Standard 20 Freeness levels using a Sprout-Bauer 12-1 CP pressurized laboratory refiner. The first stage refining involves size reduction from chips to matchstick material and was conducted at approximately 30% consistency. All subsequent refining stages were performed at 15% consistency. Chip pre-steaming was conducted for 3 to 5 minutes by direct injection of 206,8 kPa (30 psig) steam. In subsequent refining stages, the pulp was 25 heated by steaming with low-pressure steam 13,8-20,7 kPa (2-3 psig) by direct injection to heat the wood to 100 *C. The energy consumption at each CSF level was measured (table 1). Wood chips from sample 2 which were not subjected to chlorine dioxide treatment were pre-steamed and refined to the same CSF levels using the same 30 equipment and procedures as the wood of sample 1 to establish a base energy consumption for the refining process. Table 1 shows the total energy requirement versus the CSF for wood chips not subjected to a chlorine dioxide containing gas (control) and wood chips treated with a chlorine dioxide containing gas as outlined above (treated). 35 WO 01/59203 7 PCT/SE01/00257 Table 1 CSF Total Energy kWatt-hour/metric tonne Control Treated Delta % 750 876 532 39 700 969 580 40 650 1069 632 41 600 1177 689 42 550 1294 750 42 500 1423 816 43 450 1565 890 43 400 1723 973 44 350 1903 1067 44 300 2111 1175 44 250 2357 1303 45 200 2657 1459 45 150 3045 1661 45 100 3591 1946 46 50 4525 2432 46 Table 1 clearly shows a significant reduction in the energy requirement when 5 producing mechanical pulp using wood chips treated with chlorine dioxide containing gas. In the commercially relevant area, i.e. CSF between 50 and 150 ml, the energy requirement for the treated chips is approximately 45% lower than the untreated chips.
Claims (11)
1. A process for the removal of lignin from lignocellulose containing material comprising treating the lignocellulose containing material prior to a high-yield pulping process with a delignifying gas, c h a r a c t e r i s e d in that the gas comprises 5 gaseous compounds comprising at least one oxygen atom.
2. A process according to claim 1, c h a r a c t e r i s e d in that the delignifying comprises chlorine dioxide, nitrogen oxides, carbon dioxide or sulphur dioxide or mixtures thereof.
3. A process according to claim 1 or 2, c h a r a c t e r i s e d in that the gas 10 comprises chlorine dioxide.
4. A process according to any of the claims, c h a r a c t e r i s e d in that the charge of chlorine dioxide is from about 0.5 kg active C1 2 per tonne oven dry lignocellulose containing material up to about 300 kg active Cl 2 per tonne oven dry lignocellulose containing material. 15
5. A process according to claim 4, c h a r a c t e r i s e d in that the charge of chlorine dioxide is from about 2 kg active C12 per tonne oven dry lignocellulose containing material up to 100 kg active C1 2 per tonne oven dry lignocellulose containing material.
6. A process according to any of the preceding claims, c h a r a c t e r i s e d in that the concentration of chlorine dioxide comprised in the delignifying gas is from about 20 0.05 up to about 100 % by volume.
7. A process according to claim 6, c h a r a c t e r i s e d in that in that the concentration of chlorine dioxide comprised in the delignifying gas is from about 0.05 up to about 50 % by volume.
8. A process according to any of the preceding claims, c h a r a c t e r i s e d in 25 that the pressure in the treatment with the delignifying gas is from about 10 kPa up to about 500 kPa.
9. A process according to any of the preceding claims, c h a r a c t e r i s e d in that the temperature in the treatment is from about 10 up to about 400 *C.
10. A process according to any of the preceding claims, c h a r a c t e r i s e d in 30 that the lignocellulose containing material prior to the treatment with the delignifying gas is subjected to steaming and/or evacuation.
11. A process according to any of the preceding claims, c h a r a c t e r i s e d in that treatment with a delignifying gas is operated in batch or continuous mode.
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US50138400A | 2000-02-09 | 2000-02-09 | |
US09/501384 | 2000-02-09 | ||
EP00850037A EP1130155A1 (en) | 2000-03-01 | 2000-03-01 | Pulping process |
EP00850037 | 2000-03-01 | ||
PCT/SE2001/000257 WO2001059203A2 (en) | 2000-02-09 | 2001-02-08 | Pulping process |
Publications (2)
Publication Number | Publication Date |
---|---|
AU3256101A true AU3256101A (en) | 2001-08-20 |
AU778689B2 AU778689B2 (en) | 2004-12-16 |
Family
ID=26074189
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
AU32560/01A Ceased AU779711B2 (en) | 2000-02-09 | 2001-02-08 | Pulping process |
AU32561/01A Ceased AU778689B2 (en) | 2000-02-09 | 2001-02-08 | Pulping process |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
AU32560/01A Ceased AU779711B2 (en) | 2000-02-09 | 2001-02-08 | Pulping process |
Country Status (7)
Country | Link |
---|---|
EP (2) | EP1264038A2 (en) |
JP (2) | JP2003522844A (en) |
AU (2) | AU779711B2 (en) |
CA (2) | CA2399723A1 (en) |
NO (2) | NO20023712L (en) |
NZ (1) | NZ520518A (en) |
WO (2) | WO2001059202A2 (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101087749B (en) | 2004-12-23 | 2010-06-09 | 国际壳牌研究有限公司 | A process for the hydrogenation of a lactone or of a carboxylic acid or an ester having a gamma-carbonyl group |
US20070034345A1 (en) * | 2005-06-15 | 2007-02-15 | Leonardus Petrus | Process for organosolv pulping and use of a gamma lactone in a solvent for organosolv pulping |
US8580978B2 (en) | 2009-08-07 | 2013-11-12 | Shell Oil Company | Process for preparing a hydroxyacid or hydroxyester |
ES2828623T3 (en) | 2016-07-27 | 2021-05-27 | Padlock Therapeutics Inc | Covalent PAD4 inhibitors |
CN109972436A (en) * | 2017-12-28 | 2019-07-05 | 北京小池原品科技有限公司 | A kind of method of bamboo material manufacture paper for daily use |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB567774A (en) * | 1942-08-24 | 1945-03-02 | George Brainard Fowler | Improvements in or relating to processes of treating cellulosic raw material, and the improved cellulosic fibres resulting therefrom |
US3591451A (en) * | 1969-02-06 | 1971-07-06 | Ethyl Corp | Pretreatment of vegetable matter and delignification of the refined matter with chloring dioxide |
US4211605A (en) * | 1978-08-03 | 1980-07-08 | Canadian International Paper Company | High yield chemimechanical pulping processes |
SE450393B (en) * | 1981-10-27 | 1987-06-22 | Mo Och Domsjoe Ab | PROCEDURE FOR TREATMENT OF WOOD WITH NITROGEN OXIDES AND OBJECTIVE SULFATE COOKING |
SU1416576A1 (en) * | 1986-08-14 | 1988-08-15 | Ленинградская лесотехническая академия им.С.М.Кирова | Method of producing semi-finished cellulose product |
SE466964B (en) * | 1988-03-01 | 1992-05-04 | Sca Pulp Ab | PRE-TREATMENT OF CHIP MEDIUM SULFUR Dioxide DURING SULPHAT Pulp PREPARATION |
FI85389C (en) * | 1989-12-12 | 1992-04-10 | Enso Gutzeit Oy | Process for mass production |
SE9002039D0 (en) * | 1990-06-07 | 1990-06-07 | Svenska Traeforskningsinst | SAVE TO PREPARE |
DK0651832T3 (en) * | 1991-08-23 | 1998-05-11 | Olin Corp | Method for gas phase delignification of wood fiber pulp |
FR2701274B1 (en) * | 1993-02-09 | 1995-03-31 | Air Liquide | Process for the manufacture of bleached chemical thermal mechanical pulp (CTMP). |
-
2001
- 2001-02-08 NZ NZ520518A patent/NZ520518A/en not_active IP Right Cessation
- 2001-02-08 CA CA002399723A patent/CA2399723A1/en not_active Abandoned
- 2001-02-08 CA CA002399772A patent/CA2399772A1/en not_active Abandoned
- 2001-02-08 AU AU32560/01A patent/AU779711B2/en not_active Ceased
- 2001-02-08 JP JP2001558527A patent/JP2003522844A/en active Pending
- 2001-02-08 WO PCT/SE2001/000256 patent/WO2001059202A2/en active IP Right Grant
- 2001-02-08 EP EP01904736A patent/EP1264038A2/en not_active Withdrawn
- 2001-02-08 WO PCT/SE2001/000257 patent/WO2001059203A2/en active IP Right Grant
- 2001-02-08 JP JP2001558528A patent/JP2003522845A/en active Pending
- 2001-02-08 EP EP01904735A patent/EP1264037A2/en not_active Withdrawn
- 2001-02-08 AU AU32561/01A patent/AU778689B2/en not_active Ceased
-
2002
- 2002-08-06 NO NO20023712A patent/NO20023712L/en not_active Application Discontinuation
- 2002-08-06 NO NO20023711A patent/NO20023711L/en not_active Application Discontinuation
Also Published As
Publication number | Publication date |
---|---|
AU3256001A (en) | 2001-08-20 |
AU779711B2 (en) | 2005-02-10 |
CA2399772A1 (en) | 2001-08-16 |
CA2399723A1 (en) | 2001-08-16 |
AU778689B2 (en) | 2004-12-16 |
JP2003522845A (en) | 2003-07-29 |
WO2001059203A3 (en) | 2002-01-03 |
EP1264038A2 (en) | 2002-12-11 |
WO2001059202A3 (en) | 2002-01-03 |
NZ520518A (en) | 2004-02-27 |
NO20023711D0 (en) | 2002-08-06 |
NO20023711L (en) | 2002-10-04 |
WO2001059202A2 (en) | 2001-08-16 |
NO20023712D0 (en) | 2002-08-06 |
NO20023712L (en) | 2002-10-04 |
EP1264037A2 (en) | 2002-12-11 |
WO2001059203A2 (en) | 2001-08-16 |
JP2003522844A (en) | 2003-07-29 |
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