Sulfur Dioxide Patents (Class 162/64)
  • Patent number: 8578625
    Abstract: A process for removing water and solutes from the lumens of green wood, while leaving the cell walls throughout the wood uniformly fully swollen, comprises subjecting the green wood to supercritical carbon dioxide.
    Type: Grant
    Filed: October 29, 2007
    Date of Patent: November 12, 2013
    Assignee: New Zealand Forest Research Institute Limited
    Inventors: Robert Arthur Franich, Sheryl Suzanne Gallagher, Hendricus Wilhelmus Kroese
  • 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: 20120237989
    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: Application
    Filed: September 19, 2008
    Publication date: September 20, 2012
    Applicant: API Intellectual Property Holdings, LLC
    Inventors: Theodora Retsina, Vesa Pylkkanen
  • 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: 20110165643
    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: Application
    Filed: January 11, 2011
    Publication date: July 7, 2011
    Inventors: THEODORA RETSINA, VESA PYLKKANEN
  • Publication number: 20090236060
    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: March 23, 2009
    Publication date: September 24, 2009
    Inventors: Theodora Retsina, Vesa Pylkkanen, Adriaan van Heiningen
  • Patent number: 5041192
    Abstract: An improved wood pulping process for the delignification of wood in a solvent wherein the solvent is a supercritical fluid under supercritical conditons and contains a delignification agent such as sodium hydroxide, sodium sulfide and/or sodium bisulfate.
    Type: Grant
    Filed: September 16, 1988
    Date of Patent: August 20, 1991
    Assignee: University of South Florida
    Inventors: Aydin K. Sunol, Shan L. Chen
  • Patent number: 4756800
    Abstract: A method of producing salts of monoperoxysulfuric acid comprising reacting together, in the presence of a catalyst consisting of cupric ions in a concentration of at least 0.01 part per milion, (a) a solution of aerated water having a pH of from about 8 to about 14, and (b) a sulfur-containing reactant, wherein said reactant comprises sulfur dioxide or a sulfite. If a pulp is added to the reaction mixture and the cupric ion concentration is increased, the monoperoxysulfuric acid salts that are genrated in situ in the reaction mixture will simultaneously bleach the pulp.
    Type: Grant
    Filed: September 3, 1986
    Date of Patent: July 12, 1988
    Assignee: The United States of America as represented by the Secretary of Agriculture
    Inventors: Edward L. Springer, James D. McSweeny
  • Patent number: 4259147
    Abstract: A versatile process and apparatus is presented for producing, in high yields, many different grades of pulp from a single wood specie or for pulping any specie or type of woody material, and for storage and recycling of the by-product liquid and gaseous materials. The process of this invention is virtually pollution free, and the reactant chemicals are recoverable from the by-products. In the alternative, the by-products themselves have a commercial value which may forestall recovery of the reactants. The lignin constituent extracted from the pulp is usable as a resin binder, a wood rehardening agent, or a glue.
    Type: Grant
    Filed: October 11, 1979
    Date of Patent: March 31, 1981
    Assignee: New Fibers International
    Inventor: John Gordy
  • Patent number: 4211605
    Abstract: An improved, three-stage process for producing high yield chemimechanical pulps from wood or other lignocellulosic materials, such as chips, whereby, in the first stage, the wood or other lignocellulosic material is treated with sulfur dioxide gas or aqueous solution of sulfur dioxide, whereby sufficient sulfur dioxide is present to provide an amount of at least about 1 percent by weight based on weight of wood or other lignocellulosic material; in the second stage, said wood is sulfonated in an aqueous solution of sodium sulfite at a temperature of between about 100.degree. C. and 150.degree. C. for between about 10 and 90 minutes, said aqueous solution having a pH of between about 6 and 8.5 at the end of said sulfonating, without reducing the pulp yield to below about 90 percent; and, in the third stage, subjecting the resulting sulfonated wood to mechanical defibration.
    Type: Grant
    Filed: August 3, 1978
    Date of Patent: July 8, 1980
    Assignee: Canadian International Paper Company
    Inventors: William R. Saxton, William H. Lawford