Digestion Fluid Reused On Different Fibrous Materials Patents (Class 162/37)
  • Patent number: 9227780
    Abstract: Storage apparatus includes a supporting base (11) supporting silos (14) having a lower conical portion (15) and silo port (16) controlled by an outlet knifegate valve (17), and a charging port (20) controlled by an inlet knifegate valve (21). An upper portion (22) of the silo is closed by a domed top (18). The silo ports (16) are manifolded to a common outlet (not shown). A charge manifold (25) interconnects the respective upper charging ports (20) and connects the ports to the cuttings source conduit (26). A pressure/vacuum port (27) is connected via cycle control valve (30) to an ejector assembly (not shown) valved to be able to cycle between a vacuum phase and a pressure phase of about 16 psig using a compressed air source. Control means is selectively operable to control the outlet valve (17), inlet valve (21) and cycle control valve (30).
    Type: Grant
    Filed: January 20, 2010
    Date of Patent: January 5, 2016
    Assignee: Pentair Flow Services AG
    Inventor: Mark Krohn
  • Patent number: 8980050
    Abstract: A method for treating a cellulosic material comprising extracting the cellulosic material with an extractant to selectively extract hemicellulose therein and separating the extracted hemicellulose to form a cellulosic product comprising less hemicellulose than the cellulosic material. The extractant comprises an amine oxide and a non-solvent. The cellulosic product retains the cellulosic fiber morphology.
    Type: Grant
    Filed: March 14, 2013
    Date of Patent: March 17, 2015
    Assignee: Celanese International Corporation
    Inventors: Rongfu Li, Jay Mehta, Xiaoyan Tu, Prabuddha Bansal, Michael Combs, Denis Fallon, Lawton E Kizer
  • Patent number: 8709203
    Abstract: During nanocrystalline cellulose (NCC) production, a considerable amount of sulphuric acid is used. After the separation of the NCC, the remaining solution contains sugars and residual sulphuric acid. The sugars are in the monomeric and oligomeric forms. To reduce the cost of NCC production and to produce other added-value products, the spent acid stream can be fractionated into sugar oligomers, sugar monomers, and acid. The acid can be recycled to the NCC manufacturing process after concentration. The sugar monomers and sugar oligomers can be used for the manufacturing of other valuable chemicals. Membrane nanofiltration can be used to achieve this objective. A polymeric membrane with a molecular weight cut-off in the range of 200 Dalton was employed. Using this approach, the majority of the acid was recovered in the permeate while the sugars were concentrated in a smaller stream. The sugar level in the separated acid/permeate stream was only about 3% of the original concentration.
    Type: Grant
    Filed: July 28, 2010
    Date of Patent: April 29, 2014
    Assignee: Fpinnovations
    Inventors: Naceur Jemaa, Michael Paleologou, Xiao Zhang
  • Publication number: 20140102648
    Abstract: A method to pulp cellulosic fibrous material including: alkaline cooking cellulosic fibrous material in a continuous digester vessel to produce a pulp having a kappa number in a range of 50 to 120; washing the pulp discharged from the digester vessel; treating the washed pulp in the presence of oxygen and alkali to remove lignin; washing the oxygen-treated pulp such that the kappa number is recued by at least at least 30; separating lignin from wash filtrate generated by the washing of the oxygen-treated pulp, and using the separated wash filtrate as a washing liquid in the washing of the pulp from the digester vessel.
    Type: Application
    Filed: March 21, 2012
    Publication date: April 17, 2014
    Applicant: Andritz OY
    Inventors: Janne Vehmaa, Johan Engstrom, Jussi Piira
  • Patent number: 8328983
    Abstract: A method of producing a modified pulp for use in paper or paper web products, the method comprising treating wood chips in an extraction process to remove hemicellose to form treated wood chips; and subjecting said treated wood chips to chemical or semichemical pulping to form a modified Kraft pulp wherein the amount of hemicellulose contained in the modified Kraft pulp is from about 5 to about 10% by dry weight of the modified pulp.
    Type: Grant
    Filed: May 24, 2006
    Date of Patent: December 11, 2012
    Assignee: International Paper Company
    Inventors: Zheng Tan, Gopal Goyal, Alexander A Koukoulas
  • Publication number: 20120305207
    Abstract: A method for the fractionation of lignocellulosic materials into cellulose, hemicelluloses and lignin in a batch or continuous process in a treatment with vaporous mixture of aliphatic alcohol, sulfur dioxide and water. Cooking conditions are varied to get different proportions of cellulose, hemicelluloses and lignin. Chemical recovery through pressure release is described.
    Type: Application
    Filed: August 14, 2012
    Publication date: December 6, 2012
    Applicant: API INTELLECTUAL PROPERTY HOLDINGS, LLC
    Inventors: Theodora RETSINA, Vesa PYLKKANEN, Adriaan Reinhard P. VAN HEININGEN
  • Publication number: 20120211183
    Abstract: A pulp cooking system including: a cellulosic material feed system, a pre-hydrolysis reactor vessel and a Kraft cooking reactor vessel. The feed material system includes a steaming chip bin and a high pressure transfer device. The pre-hydrolysis reactor vessel maintains the feed material in a mildly acidic condition and allows hydrolysate to be extracted through screens below a hydrolysis zone in the vessel. A wash zone is below the screens and allows wash liquid to flow through the feed material in a cross-current direction. The wash liquid and hydrolysate removed from the feed material is extracted through the screens. The feed material is maintained in a mildly acidic condition through the pre-hydrolysis reactor vessel until the material enters the Kraft cooking vessel where the feed material is treated with alkaline cooking liquors.
    Type: Application
    Filed: February 1, 2012
    Publication date: August 23, 2012
    Applicant: Andritz Inc.
    Inventors: Aaron LEAVITT, Jussi Pakarinen, Brian F. Greenwood
  • Publication number: 20120211184
    Abstract: During nanocrystalline cellulose (NCC) production, a considerable amount of sulphuric acid is used. After the separation of the NCC, the remaining solution contains sugars and residual sulphuric acid. The sugars are in the monomeric and oligomeric forms. To reduce the cost of NCC production and to produce other added-value products, the spent acid stream can be fractionated into sugar oligomers, sugar monomers, and acid. The acid can be recycled to the NCC manufacturing process after concentration. The sugar monomers and sugar oligomers can be used for the manufacturing of other valuable chemicals. Membrane nanofiltration can be used to achieve this objective. A polymeric membrane with a molecular weight cut-off in the range of 200 Dalton was employed. Using this approach, the majority of the acid was recovered in the permeate while the sugars were concentrated in a smaller stream. The sugar level in the separated acid/permeate stream was only about 3% of the original concentration.
    Type: Application
    Filed: July 28, 2010
    Publication date: August 23, 2012
    Applicant: Fpinnovations
    Inventors: Naceur Jemaa, Michael Paleologou, Xiao Zhang
  • Publication number: 20120168102
    Abstract: A method for producing pulp by extracting hemicellulosic materials from lignocellulosic materials using water in an extraction stage, wherein the extraction stage is either a single extraction or a double extraction process; treating the lignocellulosic materials with an oxidizing agent in a treatment stage, wherein the treatment stage is selected from the group consisting of a second extraction process, an agent impregnation process, and a first pretreatment process; treating the lignocellulosic materials with a reducing agent in the treatment stage, wherein the treatment stage is selected from the group consisting of the second extraction process, the agent impregnation process, and a second pretreatment process; and then subjecting the lignocellulosic materials to a modified Kraft pulping process to produce pulp.
    Type: Application
    Filed: April 2, 2010
    Publication date: July 5, 2012
    Inventors: Sung-Hoon Yoon, Harry T. Cullinan, Gopal A. Krishnagopalan
  • Publication number: 20110268652
    Abstract: The present invention relates to an integrated method for producing cellulose and at least one low-molecular-weight reusable material, in which a starting material containing lignocellulose is provided and subjected to a decomposition with a processing medium. A fraction enriched with cellulose and a fraction depleted of cellulose is then isolated from the decomposition material, the depleted fraction of cellulose being subjected to a treatment during which at least one low-molecular-weight reusable material is obtained.
    Type: Application
    Filed: September 7, 2009
    Publication date: November 3, 2011
    Applicant: BASF SE
    Inventors: Otto Machhammer, Jochem Henkelmann, Wolfgang Rohde, Mario Emmeluth, Sonja Giesa
  • Publication number: 20110226428
    Abstract: The first invention aims to provide a method for preparing stiffer bulky pulp at a freeness level comparable to that obtained by mechanical treatments to improve the bulkiness of product paper by searching for a method capable of adjusting freeness while suppressing damage to pulp fibers and internal fibrillation in a process for producing pulp. The second invention aims to strip contaminants deposited on pulp fibers and/or inorganic particles to reduce adhesion of the contaminants and decrease microorganisms in a treatment of process water containing long pulp fiber fractions used in a process for producing pulp and paper, thereby clarifying process water and thus preparing high-quality pulp and paper.
    Type: Application
    Filed: May 23, 2011
    Publication date: September 22, 2011
    Applicant: NIPPON PAPER INDUSTRIES CO., LTD.
    Inventors: Shisei Goto, Hiromichi Tsuji, Keigo Watanabe, Takeshi Iimori
  • Publication number: 20110108223
    Abstract: A method for the fractionation of lignocellulosic materials into cellulose, hemicelluloses and lignin in a batch or continuous process in a treatment with vaporous mixture of aliphatic alcohol, sulfur dioxide and water. Cooking conditions are varied to get different proportions of cellulose, hemicelluloses and lignin. Chemical recovery through pressure release is described.
    Type: Application
    Filed: January 11, 2011
    Publication date: May 12, 2011
    Inventors: Theodora Retsina, Vesa Pylkkanen, Adriaan Renhard P. Van Heiningen
  • Patent number: 7686919
    Abstract: The continuous digester system has an inlet defined therein for the feed of a chips suspension and an outlet for the output of a cooked suspension of pulp. The suspension or chips is fed in to the inlet through a line at the beginning of the cook, where the chips suspension has a volume of starting cooking fluid that establishes a fluid/wood ratio that is greater than 3.5. A final cooking fluid is present during the cook for the major part of the cook and is withdrawn through a withdrawal strainer only during the final 15 minutes of the cook. The final cooking fluid ensures a fluid/wood ratio that is greater than 3.5 in association with the withdrawal. The withdrawn final cooking fluid during the final 15 minutes of the cook consists of spent black liquor that maintains a residual alkali level that lies under 15 g/l.
    Type: Grant
    Filed: November 24, 2006
    Date of Patent: March 30, 2010
    Assignee: Metso Fiber Karlstad AB
    Inventors: Vidar Snekkenes, Mikael Lindstrom
  • Patent number: 7553394
    Abstract: In the process for producing kraft pulp, performing a potassium ion removal step of flowing an aqueous solution containing ashes recovered from a combustion exhaust gas generated in a black solution combustion step by a dust collector through a packed bed filled with a sodium-type cation exchange organic resin to adsorb and remove potassium ions contained in the aqueous solution; and a regeneration step of treating the cation exchange organic resin used in the potassium ion removal step with a solution consisting essentially of aqueous sodium hydroxide to regenerate the cation exchange resin, where a fraction recovered from the potassium ion removal step which is rich in sodium sulfate and sodium carbonate is recycled to the black solution concentrating step, and a sodium hydroxide effluent recovered from the regeneration step is recycled to a bleaching step and used in a bleaching process.
    Type: Grant
    Filed: September 11, 2003
    Date of Patent: June 30, 2009
    Assignees: Nippon Rensui Co., Hokuetsu Paper Mills, Ltd.
    Inventors: Saburo Furusho, Norio Kawano, Shigeru Wakamoto
  • Patent number: 7402224
    Abstract: A method for producing paper pulp from a lignocellulosie vegetable raw material. The method includes contacting the raw material with a mixture of formic acid and acetic acid (in an amount more than 5 wt. % of the mixture) at a temperature and for a suitable reaction time, the whole being performed at room temperature. The paper pulp is separated from the organic phase and optionally bleached with ozone. The organic phase is treated to enable the recycling of the formic and acetic acids and the extraction of lignins, sugars and excess acetic acid.
    Type: Grant
    Filed: May 6, 1999
    Date of Patent: July 22, 2008
    Assignee: Compagnie Industrielle de la Matiere Vegetale
    Inventors: Gérard Avignon, Michel Delmas
  • Patent number: 7374637
    Abstract: The method is for bleaching cellulose pulp in a bleach line that has at least two bleaching steps. The filtrate distribution is led up through the bleaching line counter-currently to the flow of cellulose pulp established in the bleaching line. A single joint main conduit is used for the bleaching steps. Wash filtrates obtained from the wash steps, used after or before the bleaching step, are led in conduits to branch locations on the main conduit that are positioned downstream of the branch location for drawing off of wash and/or dilution liquor for the wash step in question. All branch points in the joint main conduit are in fluid communication with one another along the main conduit.
    Type: Grant
    Filed: November 16, 2005
    Date of Patent: May 20, 2008
    Assignee: GL&V Management Hungary kft
    Inventors: Vidar Snekkenes, Lennart Gustavsson
  • Patent number: 7285179
    Abstract: The continuous digester is for producing chemical pulp to a process for operating this digester and to a feedback system for the cooking liquid. By means of implementing cooking zones 1st, 2nd, 3rd, 4th and 5th down through the digester, that have a successively decreasing liquid-to-wood ratio, it is possible to obtain a more uniform alkali profile during the cooking. The alkali is kept high at the beginning by means of a high liquid-to-wood ratio, typically over 6:1, which exceeds conventional liquid-to-wood ratios, which are normally around 3.5-5.0:1.
    Type: Grant
    Filed: March 19, 2002
    Date of Patent: October 23, 2007
    Assignee: Metso Fiber Karlstad AB
    Inventors: Vidar Snekkenes, Mikael Lindstrom
  • Patent number: 7270725
    Abstract: The method is for the manufacture of cooked cellulose pulp in which the starting material, preferably chips, undergoes a successive increase in temperature towards cooking temperature. This is done while the chips are first treated in a pre-treatment zone in which the main part, greater than 50%, of fresh white liquor necessary for the cooking stage is added, after which this alkali-rich treatment fluid is withdrawn and replaced to a major extent by black liquor. The alkali-rich treatment fluid that has been withdrawn after the pre-treatment stage is then added to the cooking stage, which is why the addition of fresh white liquor to the cooking stage is reduced to an equivalent amount. Maximal yield-enhancing effect is obtained using poly-sulphide-rich white liquor during the pre-treatment at a temperature in the interval 60±40° C. and retention time in the interval 2-60 minutes, preferably 2-10 minutes.
    Type: Grant
    Filed: December 13, 2002
    Date of Patent: September 18, 2007
    Assignee: Metso Fiber Karlstad AB
    Inventors: Mikael Lindstrom, Vidar Snekkenes
  • Patent number: 7182835
    Abstract: Methods for bleaching chemical pulp are disclosed including dewatering the pulp to a concentration of from 25 to 40%, bleaching in a first chlorine dioxide stage, followed by a second alkaline bleaching stage, followed by a third chlorine dioxide bleaching stage, dewatering the bleached pulp to a concentration of from 10 to 40% and producing a filtrate, and recycling the filtrate to control the pulp concentration of the dewatered chemical pulp to from 8 to 15% in the first bleaching stage.
    Type: Grant
    Filed: August 14, 2001
    Date of Patent: February 27, 2007
    Assignee: Metso Paper, Inc.
    Inventors: Lars-Åke Lindström, Solveig Nordén, Gunnar Carré
  • Patent number: 7112256
    Abstract: A method for the continuous cooking of chemical pulp with the aim of achieving improved heat economy in a digester system having a vessel (1) for impregnation and a vessel (2) for cooking the impregnated cellulose chips. A part of the black liquor (14) withdrawn from the digester (2) is added at the beginning of a transfer system (4) to increase the temperature of the chips mixture in the transfer system (4). A fraction of the transport fluid (10) from the transfer system (4) that is continuously withdrawn from the impregnated chips fed into the top of the digester is returned to the impregnation vessel (1) at essentially the maintained transfer temperature.
    Type: Grant
    Filed: January 22, 2003
    Date of Patent: September 26, 2006
    Assignee: Kvaerner Pulping AB
    Inventors: Vidar Snekkenes, Lennart Gustavsson
  • Patent number: 7097738
    Abstract: The invention relates to a process for producing pulp from a fibre-based raw material using, as the cooking reagent, a solvent mixture which is based on organic acids and also contains furfural. The method is applicable to herbaceous plants, in particular.
    Type: Grant
    Filed: July 11, 2002
    Date of Patent: August 29, 2006
    Assignee: Chempolis Oy
    Inventors: Esa Rousu, Pasi Rousu, Juha Anttila, Päivi Rousu
  • Patent number: 6946057
    Abstract: The present invention relates to a new and environmentally sound process for the manufacturing of a chemical pulp from lignocellulosic material with an integrated recovery system for recovery of pulping chemicals. The process is carried out in several stages involving a pre-treatment stage followed by one or more delignification stages using an alkaline buffer solution comprising alkali metaborate and sodium carbonate as major components. The alkaline components of the pulping liquor are recovered from a chemicals recovery furnace and at least a portion of the alkali is recycled and used for delignification without any prior reactions with lime or calcium compounds for generation of alkali hydroxide. A quinone based delignification catalyst may be added to be present during delignification.
    Type: Grant
    Filed: September 12, 2003
    Date of Patent: September 20, 2005
    Assignee: Kiram AB
    Inventor: Lars Stigsson
  • Patent number: 6942754
    Abstract: Xylooligosaccharide is produced from a lignocellulose pulp by enzyme-treating a lignocellulose pulp with hemicellulase, filtering the resultant reaction mixture to separate a liquid fraction from the enzyme-treated pulp, subjecting the separated liquid fraction to a permeation treatment through a separation membrane to separate a non-permeated fraction containing xylooligosaccharide-lignin complex with an increased concentration from a permeated fraction, collecting the non-permeated fraction, and separating and recovering xylooligosaccharide from the collected non-permeated fraction.
    Type: Grant
    Filed: April 22, 2002
    Date of Patent: September 13, 2005
    Assignee: Oji Paper Co., Ltd.
    Inventors: Yoshiya Izumi, Jun Sugiura, Hitoshi Kagawa, Naoya Azumi
  • Publication number: 20040261960
    Abstract: The process is for continuously cooking chemical pulp in a digester system consisting of at least one vessel for impregnating and cooking comprising an inlet into which a mixture of chips and process liquid is fed. The chips are impregnated at a predetermined impregnation temperature, Timp, and cooked at a predetermined cooking temperature, Tcook, after which dissolved pulp is fed out at the outlet of the digester system. The process liquid which is continually extracted is retained outside the digester system during a dwell time, t, of at least 30 min, without any heating above 140°, and thereafter returned to the digester system to a position which is substantially at the same level as the extraction, or downstream thereof, and thereby constitute part of the process liquid in the subsequent treatment zone. The process results in improved tear strength, beatability, bleachability and reduced color reversion, and increased yield across the digester.
    Type: Application
    Filed: May 3, 2004
    Publication date: December 30, 2004
    Inventors: Catrin Gustavsson, Mikael Lindstrom, Krister Olsson, Vidar Snekkenes
  • Publication number: 20040244925
    Abstract: The invention provides for methods for producing pulp (comprising cellulose) and lignin from lignocellulosic material, such as wood chips. The methods involve acid catalyzed hydrolysis. Lignocellulosic material having a relatively high moisture concentration can be used as the starting material. The lignocellulosic material is impregnated with an acid (preferably nitric acid) and heated. During the heating lignin is depolymerized at relatively low temperatures, and the acid catalyst is distilled off. The acid catalyst can be collected and recycled after impregnation and heating. The lignocellulosic material is then digested in an alkaline solution under heat, dissolving the lignin and allowing the pulp to be removed. Acid is added to the black liquor to precipitate the lignin which is then removed. The resultant amber liquor can be further processed into other ancillary products such as alcohols and/or unicellular proteins.
    Type: Application
    Filed: December 8, 2003
    Publication date: December 9, 2004
    Inventor: David Tarasenko
  • Publication number: 20040154760
    Abstract: The invention includes a treatment apparatus for treating fibrous cellulosic raw material suitable for use in a paper making plant comprising extracting means for extracting contrary material from the raw material, crushing means for crushing the raw material to remove nodes therefrom and splitting means for splitting the crushed raw material lengthways. A co-rotating twin screw conveyor is used to pulp the crushed material, the conveyor being divided up into a plurality of zones, means for inserting treatment materials into a least one zone and means for controlling the temperature and/or pressure of all of the zones. The black liquor effluent produced in the pulping process is treated in an apparatus comprising an evaporator for concentrating the liquor to 30-70% solids, a processing vessel for treating the concentrated liquor at a temperature of between 300-600° C., and a closed conveyor for transporting the concentrated liquor from the evaporator to the processing vessel in excess of 90° C.
    Type: Application
    Filed: February 6, 2004
    Publication date: August 12, 2004
    Inventor: Trevor Dean
  • Publication number: 20040112554
    Abstract: The invention relates to a continuous digester for producing chemical pulp, to a process for operating this digester and to a feedback system for the cooking liquid. By means of implementing cooking zones 1st, 2nd, 3rd, 4th and 5th down through the digester, having a successively decreasing liquid-to-wood ratio, it is possible to obtain a more uniform alkali profile during the cooking. The alkali which is totally available is kept high at the beginning by means of a high liquid-to-wood ratio, typically well over 6:1, which well exceeds conventional liquid-to-wood ratios, which are normally around 3.5-5.0:1. In combination with digester liquid from subsequent cooking zones being fed back to the top of the digester, the alkali concentration can be kept low at the beginning of the cooking, typically within 20-35 g/l when cooking softwood. This is achieved with essentially all the alkali, i.e. more than 80%, being added at the beginning of the cooking.
    Type: Application
    Filed: September 10, 2003
    Publication date: June 17, 2004
    Inventors: Vidar Snekkenes, Mikael Lindstrom
  • Publication number: 20040099386
    Abstract: Separation of dissolved and colloidal high molecular weight organic by-products from liquors or filtrates in a cellulosic pulping process to improve the overall efficiency of the process.
    Type: Application
    Filed: November 20, 2003
    Publication date: May 27, 2004
    Inventor: Craig A. Bianchini
  • Publication number: 20040060672
    Abstract: A method for the continuous cooling of chemical pulp with the aim of achieving improved heat economy in a digester system comprising a vessel (1) for impregnation and a vessel (2) for cooking the impregnated cellulose chips. A part of the black liquor (14) withdrawn from the digester (2) is added at the beginning of a transfer system (4) having maintained essentially the withdrawl temperature, increasing the temperature of the chips mixture in the transfer system (4). A fraction of the transport fluid (10) from the transfer system (4) that is continuously withdrawn from the impregnated chips fed into the top of the digester is returned to the impregnation vessel (1) at essentially maintained transfer temperature, at a location before the said transfer system (4), seen from the point of view of the direction of flow of the chips.
    Type: Application
    Filed: October 22, 2003
    Publication date: April 1, 2004
    Inventors: Vidar Snekkenes, Lennart Gustavsson
  • Publication number: 20040060673
    Abstract: An apparatus and process for solvent pulping of cellulose-containing biomass utilizes at least one steaming vessel, a plug screw feeder or compression screw device, at least one super-atmospheric impregnation vessel, a solvent delignification reactor capable of operating at a pressure of 350 psig or more, and a solvent containing line for introducing solvent-containing liquor at the plug screw feeder outlet or compression screw device outlet. The process and system can also include at least one series connected pressure diffuser and optionally a retention tube downstream of each pressure diffuser to provide sufficient retention time to substantially preclude re-deposition of lignin on the cellulose fibers of the biomass, a blow tank connected to the last of the pressure diffusers and retention tubes, and vessels for multistage alcohol washing.
    Type: Application
    Filed: December 9, 2003
    Publication date: April 1, 2004
    Applicant: ANDRITZ INC.
    Inventors: Joseph R. Phillips, Brian Greenwood, Bertil C. Stromberg, Thomas Pschorn
  • Publication number: 20040050509
    Abstract: Pulp, containing black liquor, is separated to produce pulp substantially free of black liquor. An organic solvent forms a layer within a vessel and adding a pulp containing black liquor will establish three layers. From the lower layer, pulp substantially free of black liquor is removed. From the upper layer, black liquor substantially free of pulp is removed, and the layer of organic solvent is retained in place within the vessel. The resulting separation, by dissimilar densities of the organic solvent and pulp containing black liquor produces black liquor devoid of additional dilution by water whereby pulp containing black liquor is separated to create pulp substantially free of black liquor and provides black liquor separated from the organic solvent.
    Type: Application
    Filed: September 16, 2002
    Publication date: March 18, 2004
    Inventor: Gene E. Lighter
  • Patent number: 6699357
    Abstract: The invention relates to a process for continuous cooking of wood chips at elevated pressure and temperature in a vertical digester (1) for production of chemically dissolved pulp. Fiber material and cooking liquor are introduced at the top of the digester and pulp is discharged from the bottom of the digester (1), via a line (8) in which the pulp is maintained at substantially the same pressure level, to a pressurized wash (7). More than 50% of the used cooking liquor (black liquor) which is extracted from the system in total is extracted from the wash filtrate of the pressurized wash. The pressurized wash is regulated so that a high temperature is maintained in the wash filtrate. The extraction is regulated so that a net co-current flow is established at the bottom of the digester.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: March 2, 2004
    Assignee: Kvaerner Pulping AB
    Inventors: Vidar Snekkenes, Lennart Gustavsson, Sven-Erik Olsson
  • Patent number: 6663749
    Abstract: A method is provided for the use of borates in the recausticization of alkali-containing liquors such as those produced in the chemical and semi-chemical pulping of wood and in the oxidation and bleaching of wood pulp. Sodium hydroxide is regenerated from sodium carbonate-containing smelts in such pulp processes by autocausticization through the addition of limited amounts of borate. Autocausticization may be carried out at boron to carbonate molar ratios below 2:1 and at sodium to boron molar ratios exceeding 3:1, resulting in high reaction efficiency. Partial autocausticization using borate may also be combined with conventional lime recausticization for the regeneration of sodium hydroxide from sodium carbonate-containing smelts.
    Type: Grant
    Filed: September 25, 2001
    Date of Patent: December 16, 2003
    Assignee: U.S. Borax Inc.
    Inventors: Charles M. Bair, Robert B. McBroom, Honghi N. Tran
  • Publication number: 20030209335
    Abstract: A method is disclosed for extracting liquor from a cellulose slurry for a continuous digester comprising the steps of: providing the cellulose slurry of liquor and chips of cellulose fiber material to a separator; extracting a first stream of liquor from the separator; extracting a second stream of liquor from the separator, where the second stream has an effective alkali (EA) concentration greater than the EA concentration of the first steam; outputting the first stream from the separator and outputting the second stream from the separator separately from the second stream, and outputting a condensed slurry from the separator to a digester vessel.
    Type: Application
    Filed: May 21, 2003
    Publication date: November 13, 2003
    Applicant: Andritz Inc.
    Inventors: Kaj O. Henricson, C. Bertil Stromberg, Richard Laakso, John F. Bolles, Keith P. Vogel, Patrick J. Sullivan
  • Patent number: 6641699
    Abstract: A chemical wood pulping process having reduced volatile organic compound emissions includes extracting wood particulates with solvent at a pressure less than 50 psi to reduce naturally-occurring particulate pitch and volatile organic compound content without significant dissolution of lignin and wood cellulosic components. The solvent used is methanol, ethanol, or acetone. This is followed by comingling the extracted wood particulates with a liquor having chemical reactants, not including the solvent used to extract the wood particulates, for solubilizing lignin. Then, allowing the chemical reactants of the liquor to react with lignin contained in the extracted wood particulates under controlled conditions of temperature and pressure for a sufficient time to solubilize and remove lignin. This is followed by producing a wood pulp having individual cellulosic fibers while releasing a reduced amount of VOCs in the wood pulping process.
    Type: Grant
    Filed: November 6, 2001
    Date of Patent: November 4, 2003
    Assignee: Weyerhauser Company
    Inventors: Jerry R. Speaks, Roger O. Campbell, Michael A. Veal
  • Publication number: 20030178163
    Abstract: A method of bleaching chemical pulp, comprising two bleaching stages (D0 and, respectively, D1) with chlorine dioxide as dominating bleaching chemical and at least one intermediate alkaline bleaching stage (E). The ingoing pulp is dewatered to a concentration of 25-40% before the first chlorine dioxide stage (D0) and to 10-40% after the second chlorine dioxide stage (D1). Filtrate from the dewatering after the second chlorine dioxide stage (D1) is re-cycled and utilized for controlling the pulp concentration to 8-15% of the dewatered pulp to the first chlorine dioxide stage (D0).
    Type: Application
    Filed: February 12, 2003
    Publication date: September 25, 2003
    Inventors: Lars-Ake Lindstrom, Solveig Norden, Gunnar Carre
  • Patent number: 6605180
    Abstract: Fiber material and cooking liquor are introduced at the top of the digester and pulp is discharged from the bottom of the digester, via a line in which the pulp is maintained at substantially the same pressure level, to a pressurized wash. More than 50% of the used cooking liquor (black liquor) which is extracted from the system in total is extracted from the wash filtrate of the pressurized wash. At the same time a small portion of the wash filtrate is also to be recirculated to the bottom of the digester as dilution liquid. The pressurized wash is regulated so that a high temperature is maintained in the wash filtrate. The extraction is regulated so that a net co-current flow is established at the bottom of the digester.
    Type: Grant
    Filed: September 28, 2001
    Date of Patent: August 12, 2003
    Inventors: Vidar Snekkenes, Lennart Gustavsson, Sven-Erik Olsson
  • Publication number: 20030131956
    Abstract: A set of spaced apart screen assemblies are provided within a continuous kraft digester. Liquor is extracted from a first screen assembly of the set without recirculation of at least a portion of the extracted liquor into the digester above the first screen. In such a manner, the need for circulation flow below the first screen assembly of the set to the second screen assembly of the set is minimized, thereby also minimizing (if not eliminating entirely) the packing problems such flow may cause. The liquor extracted from the first screen assembly in the set could be reintroduced, however, into the digester at some other location in the cooking system (e.g., at a location just above the bottom screen). By employing the present invention, the distance between the first and second screen assemblies is greater than one digester diameter (D).
    Type: Application
    Filed: November 26, 2002
    Publication date: July 17, 2003
    Inventor: C. Bertil Stromberg
  • Publication number: 20030121625
    Abstract: The present invention relates to a method for bleaching mechanical and chemithermomechanical pulp including that an advancing pulp suspension obtained after that the fibres are laid free is prebleached by adding reductive bleaching agent to the pulp suspension in a location just after the fibres are laid free and that the bleaching is carried out under given conditions in the form of high temperature and minimized oxygen access in respect of said adding location and immediately downstream of said location, characterized in, that the in the described manner prebleached pulp is subjected to at least one further bleaching treatment including that the pulp is bleached with an oxidizing bleaching agent, preferably peroxide bleaching agent, reinforced with borohydride.
    Type: Application
    Filed: November 18, 2002
    Publication date: July 3, 2003
    Inventors: Eric Yijing Zhang, Yonghao Ni, Shuyu Wang
  • Patent number: 6569284
    Abstract: The specification discloses an improved bleaching sequence which provides significant reduction in filtrate volumes and amounts of absorbable organic halide (AOX), color, and chemical oxygen demand (COD) in the effluent. These reductions are achieved without adversely affecting the brightness and viscosity properties of the bleached pulp and without a high capital cost and operating cost penalty or impact on existing mill processes. The bleaching sequence according to the invention for reducing filtrate volumes is an EOD1EOPD2 or EOPD1EOPD2 bleaching sequence wherein substantially all of the filtrates from the later bleaching stages are recycled to earlier bleaching stages and eventually treated in the initial EO or EOP stage prior to discharge from the plant.
    Type: Grant
    Filed: July 1, 1998
    Date of Patent: May 27, 2003
    Assignee: International Paper Company
    Inventors: Caifang Yin, Jasper H. Field
  • Patent number: 6544384
    Abstract: The strength properties of chemical cellulose pulp (particularly kraft pulp) are improved by substituting a cold impregnation soak for conventional impregnation procedures. After steaming, wood chips are soaked in an alkaline liquid at a temperature of about 80-110° C. (preferably 80-100° C., or 90-105° C.) for between one-half-72 hours (typically about 2-4 hours) at a pressure of about 0-15 bar (preferably about 1-5 bar), to dissolve at least about 8% of the wood (preferably about 10-20%) and at least about 15% of the lignin. The alkaline liquid used preferably contains sulfide (e.g. black liquor, green liquor, white liquor, or mixtures thereof), but almost any alkaline liquid having an alkali concentration of about 1.0 mole of NaOH/liter or less (typically about 0.75 m/l or less) is suitable. The wood chips are then raised to a cooking temperature of about 145-180° C. and cooked to produce the cellulose chemical pulp.
    Type: Grant
    Filed: October 15, 2001
    Date of Patent: April 8, 2003
    Assignee: Andritz Inc.
    Inventors: Kaj O. Henricson, Aki Hannu Vilpponen, Hannu Olavi Ramark, Auvo Kimmo Kettunen, C. Bertil Stromberg
  • Publication number: 20030019593
    Abstract: Separation of dissolved and colloidal high molecular weight organic by-products from liquors or filtrates in a cellulosic pulping process to improve the overall efficiency of the process.
    Type: Application
    Filed: July 27, 2001
    Publication date: January 30, 2003
    Inventor: Craig A. Bianchini
  • Patent number: 6468390
    Abstract: A method for continuous cooking of lignocellulosic fiber material, comprising the steps of sequentially (a) in a first stage, impregnating the fiber material in an impregnation liquid comprising alkali metal hydroxide, and thereafter withdrawing (14, 514) a spent impregnation liquid; (b) in a second stage, cooking the fiber material in a cooking liquor comprising alkali metal hydroxide; and (c) in a third stage, adding (A), to said fiber material, a liquid which is rich in hemicellulose, said liquid preferably comprising at least a part (14a, 514a) of said withdrawn spent impregnation liquid. In a fourth stage (d), the fiber material is cooked in a cooking liquor comprising the liquid added in the third stage, whereby the fiber material is subjected to a retention time of at least 1 hour in said fourth stage.
    Type: Grant
    Filed: August 24, 1998
    Date of Patent: October 22, 2002
    Assignee: Kvaerner Pulping AB
    Inventors: Vidar Martin Snekkenes, Krister Karl Erik Olsson, Bror Lennart Gustavsson, Ernst Mikael Lindström
  • Publication number: 20020129910
    Abstract: The method described herein will produce depolymerized lignins substantially free from sodium compounds. Black liquor supplied from a pulping process is utilized for providing a mixture of depolymerized lignins dispersed and dissolved in a solution containing sodium hydroxide. The mixture is then separated to form depolymerized lignins and a solution containing sodium hydroxide. Following separation, the depolymerized lignins are then extracted with water to produce an extractate containing sodium compounds. The extracted depolymerized lignins, containing sodium compounds, are then reacted with an acid to form sodium salts to form a slurry. The slurry containing sodium salts is, by means of a salt splitting method, separated from the extracted depolymerized lignins to produce substantially sodium free depolymerized lignins.
    Type: Application
    Filed: March 14, 2001
    Publication date: September 19, 2002
    Inventor: Gene E. Lightner
  • Patent number: 6350348
    Abstract: A method of cooking pulp in an alkaline batch process (using one or more batch digesters) improves pulp bleachability. The wood material is supplied to the digester; the cellulosic material is pre-treated in the digester with a first liquor, the first liquor is displaced by a second liquor, the displaced first liquor is led to a further treatment, the cellulose material is treated with the second liquor, and the cooked pulp is removed from the digester. The second liquor is displaced as two consecutive parts, i.e. as strong black liquor and weak black liquor, and after cooling in a heat exchanger the strong black liquor thus obtained is fed into the digester as the first liquor in a subsequent batch (in the same, or a different, batch digester).
    Type: Grant
    Filed: July 19, 1999
    Date of Patent: February 26, 2002
    Assignee: Andritz-Ahlstrom Oy
    Inventors: Kaj Henricson, Auvo Kettunen, Hannu Ramark
  • Patent number: 6348128
    Abstract: A method is provided for improving causticizing efficiency in the conventional lime recausticization portion of an alkaline pulping process. Such processes are commonly used in the pulping and bleaching of wood and non-wood cellulose fiber materials. The method of this invention comprises reacting an aqueous solution of sodium carbonate with lime to produce sodium hydroxide (causticization) in the presence of borate in order to improve the causticization reaction efficiency. Borate is added in an amount sufficient to provide a boron to sodium (B/Na) molar ratio in the range of between about 0.001:1 and 0.4:1, and preferably in the range of between about 0.01:1 and 0.3:1, which results in an increased causticization efficiency of up to 8% over the reaction efficiency obtained in the absence of borate.
    Type: Grant
    Filed: March 24, 1999
    Date of Patent: February 19, 2002
    Assignee: U.S. Borax Inc.
    Inventors: Honghi N. Tran, Charles M. Bair, Robert B. McBroom
  • Publication number: 20010037865
    Abstract: A new and improved way of continuously cooking fiber material, wherein temperatures and alkaline levels are controlled to be maintained within specific levels in different zones of the digesting process in order to optimize chemical consumption and heat-economy and at the same time achieve very good pulp properties. The digesting process includes a top separator that separates the transport liquid from the fiber material and permits the fiber material to be exposed to the cooking liquid.
    Type: Application
    Filed: December 14, 2000
    Publication date: November 8, 2001
    Applicant: Kvaerner Pulping AB
    Inventors: Vidar Snekkenes, Johan Engstrom, Sven-Erik Ohlsson, Per Nystrom, Soren Soderqvist, Bjorn Karlsson
  • Patent number: 6294048
    Abstract: A method is provided for the use of borates in the recausticization of alkali-containing liquors such as those produced in the chemical and semi-chemical pulping of wood and in the oxidation and bleaching of wood pulp. Sodium hydroxide is regenerated from sodium carbonate-containing smelts in such pulp processes by autocausticization through the addition of limited amounts of borate. Autocausticization may be carried out at boron to carbonate molar ratios below 2:1 and at sodium to boron molar ratios exceeding 3:1, resulting in high reaction efficiency. Partial autocausticization using borate may also be combined with conventional lime recausticization for the regeneration of sodium hydroxide from sodium carbonate-containing smelts.
    Type: Grant
    Filed: January 28, 1999
    Date of Patent: September 25, 2001
    Assignee: U.S. Borax Inc.
    Inventors: Charles M. Bair, Robert B. McBroom, Honghi N. Tran
  • Patent number: 6277240
    Abstract: In the production of chemical pulp, such as kraft pulp, it is possible to reduce the amount of ancillary equipment, and/or the size of the continuous digester vessel, while achieving enhanced uniformity of treatment by avoiding “hang ups”. Instead of providing vertical counter-current flow of liquid and comminuted cellulosic fibrous material being treated in the lower half of the digester, the counter-current flow may be a cross flow, that is substantially horizontal (e.g. radial) while the flow of the chip column is vertical. Regardless of the configuration of the digester vessel, a single pump may be utilized for all of the recirculations, or only a few pumps for all of the recirculations.
    Type: Grant
    Filed: October 2, 1998
    Date of Patent: August 21, 2001
    Assignee: Andritz-Ahlstrom Inc.
    Inventors: Bruno S. Marcoccia, C. Bertil Stromberg, Brian F. Greenwood
  • Patent number: 6203662
    Abstract: This invention relates to a new and improved way of continuously cooking fiber material, wherein temperatures and alkaline levels are controlled to be maintained within specific levels in different zones of the digesting process in order to optimize chemical consumption and heat-economy, and, at the same time, achieving very good pulp properties.
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: March 20, 2001
    Assignee: Kvaerner Pulping AB
    Inventors: Vidar Snekkenes, Johan Engström, Krister Olsson, Mikael Lindström, Christofer Lindgren, Sören Gustavsson