Cellulosic Patents (Class 210/655)
  • Patent number: 4735193
    Abstract: A process for separating a monosaccharide from an aqueous solution comprising monosaccharides and a second component comprising a polysaccharide. The mixture is contacted with a mixed matrix membrane comprising a adsorbent or molecular sieve material dispersed in an organic polymer in which the monosaccharide has a greater steady state permeability than the polysaccharide. The monosaccharide passes through the membrane, and is recovered. Particular mixed matrix membranes found to be useful in separating mono from polysaccharides are silicalite, gamma-alumina, activated carbon or a calcium exchanged Y-zeolite dispersed in cellulose acetate or polyelectrolyte complex polymers.
    Type: Grant
    Filed: February 8, 1985
    Date of Patent: April 5, 1988
    Assignee: UOP Inc.
    Inventors: Santi Kulprathipanja, Edward W. Funk, Sudhir S. Kulkarni, Y. Alice Chang
  • Patent number: 4668396
    Abstract: A dialysis membrane used for hemodialysis having a structure comprised of flat films, blown films or tubular threads of substitution-modified cellulose, in which the effects of complement activation and leukopenia are clearly reduced. The average degree of substitution of the modified cellulose is 0.02 to 0.07. Dialysis membranes, which have proven successful within the scope of the invention, contain modified cellulose, having a structure represented by the formula cellulose-Z, wherein Z represents the group --R'--X--Y.X is at least one member selected from the group consisting of ##STR1## Y is at least one member selected from the group consisting of --R, --NR.sub.2, --Si(OR").sub.3, --SO.sub.3 H, --COOH, --PO.sub.3 H.sub.2, --N.sup.+ HR.sub.2, --OR" and the salts thereof.R' is at least one member selected from the group consisting of an alkylenes cycloalkylenes and arylenes having a total of 1 to 25 carbon atoms.R" is a hydrogen atom or R.
    Type: Grant
    Filed: August 14, 1985
    Date of Patent: May 26, 1987
    Assignee: Akzo NV
    Inventors: Ulrich Baurmeister, Walter Brodowski, Michael Diamantoglou, Gustav Dunweg, Werner Henne, Michael Pelger, Helmut Schulze
  • Patent number: 4510047
    Abstract: Selective extraction solvents such as NMP, phenol or furfural employed for the extraction of specialty oils, i.e. lubricating, transformer and insulating oils, to remove undesirable aromatic components therefrom, is itself recovered from the extract stream and/or raffinate streams by preferential ultrafiltration through selective membranes of regenerated cellulose. The extract stream, because of its higher solvent content, is the preferred stream for solvent recovery treatment by the reverse osmosis membrane permeation technique. Solvent recovery employing membrane permeation exhibits the advantage of not being energy intensive as is distillation or stripping. The solvent is recovered at a high enough flux rate and at a high enough level of purity to be introduced back into the solvent extraction process optionally at some point in the process wherein the composition of the recovered solvent approximately matches the composition of the solvent present in the process at the point of introduction.
    Type: Grant
    Filed: December 14, 1983
    Date of Patent: April 9, 1985
    Assignee: Exxon Research and Engineering Co.
    Inventor: John A. Thompson
  • Patent number: 4305823
    Abstract: Polymers from the group consisting of cellulose and its ester and ether derivatives, of polyvinyl alcohol and its ester derivatives, copolymers with vinyl esters and homopolymers and copolymers of acrylates and methacrylates are modified with monofunctional or difunctional cyclic .beta.-ketonic acids or their esters, in particular with succinylsuccinic acid or its ester derivatives. The modified polymers are particularly suitable for obtaining semi-permeable membranes for osmotic separation methods.
    Type: Grant
    Filed: July 25, 1980
    Date of Patent: December 15, 1981
    Assignee: Ciba-Geigy Corporation
    Inventors: Hans Batzer, Joel Sinnreich
  • Patent number: 4247401
    Abstract: A method for the separation of organic or metallo-organic substances from salts by reverse osmosis is provided. The membranes used are asymmetric acetyl cellulose membranes modified by covalently bonded residues of reactive dyestuffs containing ionizable groups. The diameter of the pores on the surface of the membrane is 5 to 100 A.
    Type: Grant
    Filed: August 31, 1978
    Date of Patent: January 27, 1981
    Assignee: Aligena A.G.
    Inventors: Rene Bloch, Jacov Yonath
  • Patent number: 4231865
    Abstract: Improved efficiency of reverse-osmosis and ultrafiltration processes is achieved by backwashing membranes by means of electroosmosis. This is achieved by application of an electric potential across the membrane, thereby causing a backflow of water through the membrane.
    Type: Grant
    Filed: August 7, 1979
    Date of Patent: November 4, 1980
    Assignee: The United States of America as represented by the Secretary of the Interior
    Inventor: Kurt S. Spiegler