Sulfur Dioxide Or Sulfite Patents (Class 162/83)
  • Patent number: 8980051
    Abstract: This invention relates to the delignification of lignocellulosic pulp. More particularly, the invention relates to sulfonation and bleaching of the alkali pulping produced by Kraft pulp processes or produced through combination of alkali pulping processes and extended delignification stages.
    Type: Grant
    Filed: April 24, 2009
    Date of Patent: March 17, 2015
    Assignee: International Paper Company
    Inventor: Xuan T. Nguyen
  • Patent number: 8877007
    Abstract: Systems and methods are provided for refining and reclaiming rejects in a sulfite pulping process. Wood chips and sulfite cooking liquor are provided to a digester for delignification. The slurry obtained from the digester is screened to obtain a reject portion containing sulfite rejects. The sulfite rejects are disintegrated in a refiner, such that the rejects are refined to a freeness suitable for digestion in a subsequent re-cooking step. Refined rejects are then returned to the digester for re-cooking with wood chips.
    Type: Grant
    Filed: August 21, 2013
    Date of Patent: November 4, 2014
    Assignee: University of New Brunswick
    Inventors: Yonghao Ni, Guojun Kang
  • Patent number: 8864941
    Abstract: A method for the production water insoluble reactive lignin having low sulfur content and lignosulfonates from lignocellulosic material in a batch or continuous process. Lignocellulosic material is fractionated to produce water insoluble native lignin and lignosulfonates in various ratios, while preserving the cellulose and hydrolyzed hemicelluloses using water, ethanol and sulfur dioxide.
    Type: Grant
    Filed: October 8, 2013
    Date of Patent: October 21, 2014
    Assignee: API Intellectual Property Holdings, LLC
    Inventors: Thoedora Retsina, Vesa Pylkkanen
  • Patent number: 8834633
    Abstract: A method of pre-treating a cellulosic material before hydrolysis is provided. The method comprises the steps of: impregnating the cellulosic material with a reactive water-soluble gas, such as sulphur dioxide (SO2) or carbon dioxide (CO2), in an impregnation chamber to obtain impregnated material; and heating the impregnated material to obtain pre-treated material, wherein the cellulosic material is compressed right before or when it is transferred to the impregnation chamber. A corresponding system is also provided.
    Type: Grant
    Filed: December 17, 2010
    Date of Patent: September 16, 2014
    Assignee: Sekab E-Technology AB
    Inventors: Torbjörn Van Der Meulen, Stanley Forss, Lars Elfving, Staffan Magnusson, Magnus Hägglund, Anders Sjöblom
  • Patent number: 8758557
    Abstract: A process for producing fibrous material which includes the following: preparing a solution of chemicals that includes less than 25% of sulphite (calculated as Na2SO3), based on the oven-dry amount of the lignocellulosic raw material; mixing the solution of chemicals with wood in a specified liquor material; heating the solution of chemicals and the wood to a temperature above room temperature; and then either of the following alternatives: (1) removing the free-flowing solution of chemicals and digestion of the wood in the vapor phase; (2) having the wood digested in the liquid phase and separating the free-flowing solution of chemicals and the wood.
    Type: Grant
    Filed: April 4, 2007
    Date of Patent: June 24, 2014
    Assignee: Voith Patent GmbH
    Inventors: Esa-Matti Aalto, Hans-Ludwig Schubert
  • Publication number: 20140170713
    Abstract: Aspects of the AVAP® and Green Power+® technologies may be integrated, as disclosed herein. The present invention, in some variations, couples a first step of steam or hot-water extraction of biomass, with fractionation of the resulting solids using sulfur dioxide (or other acid), an alcohol (or other solvent), and water. In other variations, a first step of fractionation with sulfur dioxide (or other acid), an alcohol (or other solvent), and water is followed by treatment with steam or hot water to reduce hemicellulose content of the final solids. Some embodiments provide cellulose materials with low lignin and low hemicellulose content. Such cellulose materials are useful for making glucose by hydrolysis, as a pulp product, or as purified cellulose for making cellulose derivatives.
    Type: Application
    Filed: November 12, 2013
    Publication date: June 19, 2014
    Applicant: API Intellectual Property Holdings, LLC
    Inventors: Theodora RETSINA, Vesa PYLKKANEN
  • Publication number: 20140073016
    Abstract: The present invention relates to a method for treating a lignocellulose biomass in order to dissolve the lignin therein, while the cellulose does not dissolve. The cellulose pulp obtained can be used to produce glucose. In addition the lignin can be isolated for subsequent use in the renewable chemical industry as a source for aromatic platform chemicals.
    Type: Application
    Filed: December 15, 2011
    Publication date: March 13, 2014
    Applicant: IMPERIAL INNOVATIONS LTD.
    Inventors: Agnieszka Brandt, Richard J. Murphy, David J. Leak, Tom Welton, Jason Hallett
  • Patent number: 8585863
    Abstract: A method for the production water insoluble reactive lignin having low sulfur content and lignosulfonates from lignocellulosic material in a batch or continuous process. Lignocellulosic material is fractionated to produce water insoluble native lignin and lignosulfonates in various ratios, while preserving the cellulose and hydrolyzed hemicelluloses using water, ethanol and sulfur dioxide.
    Type: Grant
    Filed: January 11, 2011
    Date of Patent: November 19, 2013
    Assignee: API Intellectual Property Holdings, LLC
    Inventors: Theodora Retsina, Vesa Pylkkanen
  • Patent number: 8303772
    Abstract: Provided is an unbleached paper product made from grass type pulp, the unbleached paper product has a brightness of 35-60% ISO, the grass type pulp is unbleached. The unbleached paper product includes an unbleached toilet paper, an unbleached hand towel, an unbleached wiping paper, an unbleached duplicating paper, an unbleached meal container, an unbleached food wrapping paper and an unbleached printing paper. The paper products have a high intensity and have no detection of dioxin and absorbable organic halides in the harmful substance detection test.
    Type: Grant
    Filed: July 25, 2008
    Date of Patent: November 6, 2012
    Assignee: Shangdong Fuyin Paper & Environmental Protection Technology Co., Ltd.
    Inventors: Hongfa Li, Mingxin Song, Jihui Yang, Yanjin Bi, Jinxiang Xu
  • Patent number: 8268125
    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: Grant
    Filed: March 23, 2009
    Date of Patent: September 18, 2012
    Assignee: API Intellectual Property Holdings, LLC
    Inventors: Theodora Retsina, Vesa Pylkkanen, Adriaan Reinhard P. van Heiningen
  • Publication number: 20120211185
    Abstract: Compositions and processes that enhance the brightness and improve color of pulp or paper when applied during different stages of the papermaking process involving optical brighteners are identified. Used in combination with optical brighteners and/or chelants the described agents produce a synergistic effect not previously identified in the paper process.
    Type: Application
    Filed: April 30, 2012
    Publication date: August 23, 2012
    Inventors: Prasad Duggirala, Sergey Shevchenko
  • Publication number: 20110300586
    Abstract: Described herein are improved methods of pretreating lignocellulosic biomass. One aspect of the invention relates to a two-stage pretreatment process comprising a relatively low severity steam treatment, a controlled pH pretreatment, or autohydrolysis, followed by hydrolysis with dilute acid or hot water at a relatively low temperature. In certain embodiments, the methods increase hemicellulose sugar yields, substrate digestibility, and suitability for fermentation as compared to steam explosion or acid hydrolysis alone. The two-stage pretreatment processes also employ few chemicals, minimizing the costs associated with pretreatment of lignocellulosic biomass. Moreover, the two-stage pretreatment process may expand the range of suitable feedstocks for bioethanol production.
    Type: Application
    Filed: December 18, 2009
    Publication date: December 8, 2011
    Inventors: Chaogang Liu, Kevin Wenger
  • Publication number: 20110287681
    Abstract: A textile and a dye manufactured from fibers that are derived from tobacco plants and a process for making the textile and dye from the tobacco plants. In a preferred embodiment, the tobacco is organically grown and the entire tobacco plant, including stem and leaves, is utilized to produce the tobacco plant fiber used for making a textile and a natural dye utilized to color the textile or other textiles. One or more secondary material fibers can be mixed with the tobacco plant fiber to produce the textile. The process percolates a hot liquid solution onto tobacco plant material to cause a chemical reaction with the tobacco plant material to produce the tobacco plant fiber. Preferably, the process is a closed-loop system that minimizes the impact on the environment and utilizes less material, fuel and other resources. The dye does not require a mordant to bind with the textile.
    Type: Application
    Filed: May 19, 2010
    Publication date: November 24, 2011
    Inventor: Suzanne M. DeVall
  • Patent number: 8038842
    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: Grant
    Filed: January 11, 2011
    Date of Patent: October 18, 2011
    Assignee: American Process, Inc.
    Inventors: Theodora Retsina, Vesa Pylkkanen, Adriaan van Heiningen
  • Patent number: 8030039
    Abstract: A method for the production of fermentable sugars and high viscosity cellulose from lignocellulosic material in a batch or continuous process is provided. Lignocellulosic material is fractionated in a fashion that cellulose is removed as pulp, cooking chemicals can be reused, lignin is separated for the production of process energy, and hemicelluloses are converted into fermentable sugars, while fermentation inhibitors are removed. High yield production of alcohols or organic acids can be obtained from this method using the final reaction step.
    Type: Grant
    Filed: January 27, 2011
    Date of Patent: October 4, 2011
    Assignee: American Process, Inc.
    Inventors: Theodora Retsina, Vesa Pylkkanen
  • Patent number: 8012308
    Abstract: The present invention relates to a manufacturing method of mechanical pulp from stalks of corn, an annual plant, by adding a digesting agent and, prior to, during or following addition of the digesting agent, completely separating fibrous material from the cornstalks by mechanical refining. The method of the present invention comprises: (1) a first digesting process of adding 0.
    Type: Grant
    Filed: November 22, 2005
    Date of Patent: September 6, 2011
    Inventor: Hai-il Ryu
  • Publication number: 20110192560
    Abstract: The present invention relates to a process for the production of xylose and dissolving pulp from xylan-containing biomass, such as hardwood. The invention is based on prehydrolysis of the xylan-containing biomass with SO2 in specified conditions, followed by chromatographic fractionation, nanofiltration or precipitation crystallization of the xylose-containing prehydrolyzate to obtain a xylose product having a xylose content of at least 55% on DS. The dissolving pulp obtained from the process can be used for example for the production of viscose.
    Type: Application
    Filed: October 20, 2009
    Publication date: August 11, 2011
    Applicant: DANISCO A/S
    Inventors: Heikki Heikkila, Jari Lewandowski, Mirja Lindroos, Pia Saari
  • Publication number: 20100269994
    Abstract: The present invention relates to a method for treating pectin-containing ligno-cellulosic raw materials in a high-yield pulping process utilizing one or more treatment stages at alkaline conditions. The invention provides a method for controlling the alkaline treatment step, wherein the alkali is applied at a low temperature treatment stage before one or more consecutive treatment stages at the same or higher temperature. The present invention also provides pulp, paper, board or tissue obtained with said method.
    Type: Application
    Filed: October 15, 2008
    Publication date: October 28, 2010
    Inventors: Andrey Pranovich, Bjarne Holmbom, Jonas Konn
  • Publication number: 20100224333
    Abstract: The invention provides a composition of matter and a method, which enhance the process of mechanically pulping paper precursors. The composition of matter includes a small quantity of a reducing agent and a source of alkali. When added to the pulped material, e.g., wood chips, before or during mechanical pulping, the composition reduces the energy cost of the operation. In addition, not only does the composition also does not reduce the brightness of pulp, the composition can also enhance the effectiveness of subsequent bleaching processes.
    Type: Application
    Filed: March 9, 2009
    Publication date: September 9, 2010
    Inventors: Prasad Duggirala, Sergey Shevchenko
  • Publication number: 20100032111
    Abstract: A process for producing fibrous material which includes the following: preparing a solution of chemicals that includes less than 25% of sulphite (calculated as Na2SO3), based on the oven-dry amount of the lignocellulosic raw material; mixing the solution of chemicals with wood in a specified liquor material; heating the solution of chemicals and the wood to a temperature above room temperature; and then either of the following alternatives: (1) removing the free-flowing solution of chemicals and digestion of the wood in the vapor phase; (2) having the wood digested in the liquid phase and separating the free-flowing solution of chemicals and the wood.
    Type: Application
    Filed: April 4, 2007
    Publication date: February 11, 2010
    Applicant: VOITH PATENT GmbH
    Inventors: Esa-Matti Aalto, Hans-Ludwig Schubert
  • Patent number: 7648032
    Abstract: Disclosed herein are a method of reductively bleaching a mineral slurry comprising adding in the mineral slurry an effective amount of a formamidine sulfinic acid (FAS) and an effective amount of a borohydride to reductively bleach the mineral slurry, compositions comprising a mineral slurry, a FAS, and a borohydride, and final products comprising a mineral obtained by the method disclosed herein.
    Type: Grant
    Filed: March 22, 2005
    Date of Patent: January 19, 2010
    Assignee: Imerys Pigments, Inc.
    Inventors: Jun Yuan, Robert J. Pruett, Larry C. Powell
  • Publication number: 20090314443
    Abstract: A method for producing fibrous material from softwood, hardwood, or annual plants, including preparing a solution of chemicals having one of: more than 5% of chemicals for softwood, more than 3.5% of chemicals for hardwood, or more than 2.5% of chemicals for annual plants. The method includes: mixing the solution of chemicals with the lignocellulosic material in a predetermined liquor ratio; heating the solution of chemicals and the lignocellulosic material to a temperature above room temperature; and, after the heating, performing one of: removing a free-flowing portion of the solution of chemicals and digesting the lignocellulosic material in a vapor phase, or digesting the lignocellulosic material in a liquid phase and separating the free-flowing portion of the solution of chemicals and the lignocellulosic material. The produced fibrous material has a lignin content of at least 15% for softwood, at least 12% for hardwood, and at least 10% for annual plants.
    Type: Application
    Filed: April 7, 2007
    Publication date: December 24, 2009
    Inventors: Esa-Matti Aalto, Hans-Ludwig Schubert
  • Publication number: 20090266500
    Abstract: The invention relates to a process for producing a tissue web, which is produced from a stock suspension including fibers. In this case, the volume and the tearing length are to be improved with the lowest possible freeness by the stock suspension containing lignocellolosic fibrous material made of wood or annual plants which has a tearing length of more than 6.5 km at 12°SR or a tearing length of more than 8.0 km at 15°SR and a lignin content of at least 15%, based on the oven-dry fibrous material, for coniferous wood in the unbleached state, or a tearing length of more than 4.5 km at 20°SR and a lignin content of at least 12%, based on the oven-dry fibrous material, for deciduous wood in the unbleached state, or a tearing length of more than 3.5 km at 20°SR and a lignin content of at least 10%, based on the oven-dry fibrous material, for annual plants in the unbleached state.
    Type: Application
    Filed: April 30, 2009
    Publication date: October 29, 2009
    Inventors: Hans-Ludwig Schubert, Frank Peter Meltzer, Esa-Matti Aalto
  • Patent number: 7182836
    Abstract: The invention relates to a method for delignifying lignocellulosic raw materials by using sulfites in the presence of an alkaline component, especially sodium hydroxide or sodium carbonate or a mixture thereof in an aqueous solution at a high temperature and high pressure. The invention is characterized in that a first partial fragment of the alkaline component is added when the aqueous solution starts to decompose and in that at least a second partial fragment of the alkaline component is added only when delignification begins.
    Type: Grant
    Filed: July 1, 2002
    Date of Patent: February 27, 2007
    Assignee: Voith Paper Fiber Systems GmbH KG
    Inventors: Rudolf Patt, Othar Kordsachia, Bjorn Rose
  • Patent number: 7163564
    Abstract: A method for brightening virgin mechanical pulp. The method comprises combining: (i) an aqueous solution comprising sodium borohydride and sodium hydroxide; and (ii) an aqueous solution comprising sodium bisulfite, in a chemical mixer and adding output of the chemical mixer to an aqueous slurry of virgin mechanical pulp. The ratio of (moles bisulfite?moles hydroxide)/moles borohydride is from 0 to 7.8.
    Type: Grant
    Filed: October 31, 2003
    Date of Patent: January 16, 2007
    Inventors: Jean Luc Sibiet, Sundar Chellappan Jaya Krishnan, Joseph Najim, Maurice Joseph Albert Hache
  • Patent number: 7029554
    Abstract: A method for brightening pulp at a pH from 4.5 to 9. The method comprises the steps of: (a) combining an alkali metal borohydride, an alkali metal hydroxide, an alkali metal bisulfite and phosphoric acid to form a reducing solution; and (b) adding the reducing solution to a pulp slurry in an amount from 0.1% to 4% of hydrosulfite based on dry pulp fiber.
    Type: Grant
    Filed: June 19, 2003
    Date of Patent: April 18, 2006
    Assignee: Rohm and Haas Company
    Inventor: Rangamannar Goda
  • Patent number: 7018509
    Abstract: This invention relates to an improved process for manufacturing bleached thermomechanical aspen pulp having reduced yellow after treatment with aluminum based chemicals such as alum which are used in paper making processes. In this improved process the pulp is washed prior to, after or between the bleaching stages or a combination of the foregoing.
    Type: Grant
    Filed: August 31, 2002
    Date of Patent: March 28, 2006
    Assignee: International Paper Co.
    Inventors: Robin R. Kilgannon, Robert J. Kane, Eileen M. Joy, Anil K. Dewan
  • Patent number: 7001484
    Abstract: A process for peroxide bleaching of mechanical or high yield pulp, the process comprising adding to a pulp slurry at least one stabilizer for stabilizing low valency states of transition metal ions in the slurry; subsequently adding caustic soda to said slurry simultaneously with or subsequent to adding said at least one stabilizer; adding hydrogen peroxide to the slurry at a preselected point; and subjecting the slurry to preselected conditions to complete the bleaching process.
    Type: Grant
    Filed: September 23, 2002
    Date of Patent: February 21, 2006
    Assignee: University of New Brunswick
    Inventors: Yonghao Ni, Zhiqing Li
  • Patent number: 6998015
    Abstract: A method is disclosed for reducing or inhibiting alkaline darkening of mechanical pulp caused by the presence of calcium carbonate filler during production; the method comprises adding a sulfite, or sulfur-containing reducing agent, especially a sulfite to the mechanical pulp and the filler; the method is usefully applied in the production of mechanical pulp and paper in which calcium carbonate is used as a filler and also in the production of paper at neutral or mildly alkaline conditions.
    Type: Grant
    Filed: November 27, 2001
    Date of Patent: February 14, 2006
    Assignee: Pulp and Paper Research Institute of Canada
    Inventors: Xujun Hua, Makhlouf Laleg
  • Publication number: 20040256065
    Abstract: A new method for making pulp out of agricultural residue includes harvesting certain portion of plant stalk. The harvested plant stalk is bailed, transported and stored. At the mill, the plant stalk is chopped and goes through pulping process. The pulp is used to make varieties of papers with or without blending other wood based pulp.
    Type: Application
    Filed: June 18, 2003
    Publication date: December 23, 2004
    Inventors: Aziz Ahmed, Jong-Myoung Won, Haiil Ryu
  • Publication number: 20040211533
    Abstract: A method for bleaching and color stripping recycled fibers by treating the fibers with a mixture of sodium borohydride and sodium bisulfite.
    Type: Application
    Filed: April 26, 2004
    Publication date: October 28, 2004
    Inventors: Qiang Huang, Rangamannar Goda, Thomas Robert Crowley, Joseph Bettano
  • Publication number: 20040194900
    Abstract: A method of recovery of alkaline sulphite pulping chemicals and for production of steam is disclosed. The method comprises gasification of evaporated spent cooking liquor at conditions resulting in a hydrogen sulphide containing gas and a solid residue. The gas is combusted in a steam boiler, where the hydrogen sulphide is converted into sulphur dioxide and steam is produced. The solid residue is recovered in a leaching process, preferably a two-stage leaching process, where process-foreign substances are removed and the rest of the contents is divided into substantially pure sodium carbonate and a mixture of sodium carbonate, sodium sulphate and sodium sulphide. The substantially pure sodium carbonate is used for absorption of sulphur dioxide from the steam boiler.
    Type: Application
    Filed: February 19, 2004
    Publication date: October 7, 2004
    Inventor: Lennart Delin
  • Publication number: 20040188043
    Abstract: A process for bleaching substantially lignin-free pulp or paper in a single-stage bleaching process or multi-stage bleaching process; comprising
    Type: Application
    Filed: April 14, 2004
    Publication date: September 30, 2004
    Inventor: Ronald C. Naddeo
  • Publication number: 20040177937
    Abstract: The invention relates to a method for delignifying lignocellulosic raw materials by using sulfites in the presence of an alkaline component, especially sodium hydroxide or sodium carbonate or a mixture thereof in an aqueous solution at a high temperature and high pressure. The invention is characterized in that a first partial fragment of the alkaline component is added when the aqueous solution starts to decompose and in that at least a second partial fragment of the alkaline component is added only when delignification begins.
    Type: Application
    Filed: December 29, 2003
    Publication date: September 16, 2004
    Inventors: Rudolf Patt, Othar Kordsachia, Bjorn Rose
  • Publication number: 20040163779
    Abstract: Disclosed is a method for pulp bleaching. The method comprises the steps of providing a pulp sample for bleaching, the pulp sample stemming from a pulp producing process, providing a bleaching liquor comprising water and an organic component as solvent components constituting a bleaching medium, dissolved within are at least a bleaching agent, and a basic agent; and subjecting the pulp sample to the bleaching liquor for a predefined amount of time at predefined bleaching conditions. A preferred bleaching agent is hydrogen peroxide. The organic component amounts to at least 5% in weight of the bleaching medium.
    Type: Application
    Filed: February 21, 2003
    Publication date: August 26, 2004
    Inventor: George Pan
  • Patent number: 6758942
    Abstract: A process for bleaching substantially lignin-free pulp or paper in a single-stage bleaching process or multi-stage bleaching process; comprising contacting said substantially lignin-free pulp or paper with an aqueous reductive bleaching solution comprising hydroxymethane sulfinic acid during a reductive bleaching stage for sufficient amount of time to at least partially bleach said substantially lignin-free pulp or paper.
    Type: Grant
    Filed: February 15, 2002
    Date of Patent: July 6, 2004
    Assignee: Royce Associates
    Inventor: Ronald C. Naddeo
  • 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: 20040000380
    Abstract: A method for brightening pulp at a pH from 4.5 to 9. The method comprises the steps of: (a) combining an alkali metal borohydride, an alkali metal hydroxide, an alkali metal bisulfite and phosphoric acid to form a reducing solution; and (b) adding the reducing solution to a pulp slurry in an amount from 0.1% to 4% of hydrosulfite based on dry pulp fiber.
    Type: Application
    Filed: June 19, 2003
    Publication date: January 1, 2004
    Inventor: Rangamannar Goda
  • 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
  • Patent number: 6627041
    Abstract: A process for bleaching high bulk cellulosic fiber and producing a durable elevated curl index includes: (a) concurrently bleaching, heat treating and convolving cellulosic fiber pulp at elevated temperature and pressure at high consistency generally under conditions selected so as to preclude substantial fibrillation and attendant paper strength and fiber bonding development; and (b) recovering the pulp wherein the length weighted curl index of the treated fiber is at least about 20% higher than the length weighted curl index of the fiber prior to the heat treatment and convolving thereof. Preferably, the curl imparted to the fiber persists upon treatment for 30 minutes in a laboratory disintegrator at 3000 rpm at 1% consistency at a temperature of 125° F. Moreover, the curl may be imparted to the fiber in a disk refiner at very short residence times, on the order of several seconds or less.
    Type: Grant
    Filed: February 27, 2001
    Date of Patent: September 30, 2003
    Assignee: Georgia-Pacific Corporation
    Inventor: Jeffrey A. Lee
  • Patent number: 6623599
    Abstract: A papermaking process wherein calcium carbonate is included in a pulp suspension. The dissolution of the calcium carbonate in the papermaking system is substantially retarded by the introduction of carbon dioxide to said pulp suspension. The invention also provides processes for the production of paper or board in papermaking systems wherein solid calcium carbonate is present as a filler and/or pigment.
    Type: Grant
    Filed: September 1, 2000
    Date of Patent: September 23, 2003
    Assignees: AGA Aktiebolag, UPM-Kymmene Corporation
    Inventors: Auli Laurila-Lumme, Heikki Pakarinen, Hannu Juhani Leino
  • Publication number: 20030155085
    Abstract: A process for bleaching substantially lignin-free pulp or paper in a single-stage bleaching process or multi-stage bleaching process; comprising
    Type: Application
    Filed: February 15, 2002
    Publication date: August 21, 2003
    Inventor: Ronald C. Naddeo
  • Patent number: 6602385
    Abstract: A method of improving the brightness of calcium carbonate filled paper. The filled paper is dried and then bleached with an aqueous solution of a bleaching agent. The process may be used on all grades of paper that contain filler and is particularly useful in the bleaching of low brightness grade papers that are produced from mechanical pulp that contain calcium carbonate.
    Type: Grant
    Filed: January 28, 1997
    Date of Patent: August 5, 2003
    Assignee: Minerals Technologies Inc.
    Inventor: Donald Kendall Drummond
  • Publication number: 20030131958
    Abstract: A treatment sequence includes ozonation under acidic conditions followed by an acidic wash for enhancing the wet strength of a cellulosic fibrous material. Preferably the ozone treatment and the acidic wash are followed by a second ozonation step under acidic conditions. The fibrous cellulosic material obtained by this treatment sequence has a breaking length of at least 100 m. The wet strength of the cellulosic fibrous material is increased without the use of additives, such as wet strength agents. This use of ozone is very simple and efficient, and leads to highly pure products. The use of ozone as the only treatment chemical in particular avoids the introduction of so-called “non-process elements” (NPE) into the treatment system, for instance metal oxides such as MgO, which are frequently used in the oxidative treatment of pulps.
    Type: Application
    Filed: November 27, 2002
    Publication date: July 17, 2003
    Inventor: Thomas Jaschinski
  • 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
  • Publication number: 20030062138
    Abstract: The present invention is directed to an improved method for brightening mechanical pulp under neutral or alkaline papermaking conditions. The improvement comprises the steps of: (a) separating neutral or alkaline pulp dilution water into a high-solids stream and a neutral or alkaline low-solids stream; and (b) reusing the neutral or alkaline low-solids stream for pulp dilution purposes prior to a bleaching process.
    Type: Application
    Filed: April 12, 2002
    Publication date: April 3, 2003
    Inventors: Maurice Joseph Albert Hache, Rangamannar Goda
  • Publication number: 20030041985
    Abstract: The present invention is a method for producing pulp from fibrous lignocellulose material using a treatment step which exposes the material to oxalic acid, or oxalic acid and sodium bisulfite, prior to pulping. The pulping of the resulting product requires less energy input and provides a pulp having enhanced physical properties as compared to untreated materials.
    Type: Application
    Filed: March 18, 2002
    Publication date: March 6, 2003
    Inventors: Masood Akhtar, Ross E. Swaney, Eric G. Horn, Michael J. Lentz, Gary M. Scott, Cory C. Black, Carl J. Houtman, T. K. Kirk
  • 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
  • Publication number: 20020153108
    Abstract: The present innovation consists of the use of a reagent solution (FINAL COOKING ACID) where ammonium magnesium bisulphite is the active chemical. This new process is particularly useful to those industrial plants where the cellulose pulp is obtained by the magnesium acid process. The present innovation consists of the introduction of ammonium ions in the cooking acid used in such plants (initial cooking acid). The final cooking acid is obtained by the reaction of the initial cooking acid with ammonium hydroxide. Experimental results show the superiority of the present innovation over the magnesium acid bisulphite pulping process which is expressed by production of cellulosic fibres with higher mechanico-physical index values, decrease in the percentage of uncooked material, increase in wood yield and less environmental impact.
    Type: Application
    Filed: December 28, 1999
    Publication date: October 24, 2002
    Inventor: JOAO MANUEL ALMEIDA OLIVEIRA BAPTISTA
  • Patent number: 6447645
    Abstract: A feed system for a cellulose pulp treating vessel (such as a continuous digester) is not limited by the required L/W ratio of the pump feeding a wood chip slurry to a high pressure transfer device, the feed system may be kept at a low temperature to minimize flashing of liquid into steam, and a return conduit from the treatment vessel to the transfer device high pressure inlet may be eliminated. Some of the liquid is removed from the slurry just before the low pressure inlet to the transfer device, and/or just after the high pressure outlet, to reduce the L/W ratio of the slurry by at least 0.25, e.g. from 3.0:1 to 2.25:1 just before the low pressure inlet, and from, 7.0:1 to 5.0:1 substantially immediately after the high pressure outlet.
    Type: Grant
    Filed: September 17, 2001
    Date of Patent: September 10, 2002
    Assignee: Andritz Inc.
    Inventors: Mark D. Barrett, J. Robert Prough, C. Bertil Stromberg