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Using crossflow filtration to make polyester
Recovery and reuse of non-ionic surfactants Applicant." Rhodia Inc, USA Contaminated aqueous systems can be cleaned using an ultrafiltration system that allows for high recovery yields of the surfactant employed therein for recycle and reuse. The system employs specific non-ionic surfactants which remain polar and solvated at the higher operating temperatures of the system. The surfactant/contaminant containing aqueous system is ultrafihered resulting in the surfactant passing through with the permeate at extremely high yields for recovery and reuse. Patent number.. WO 99/15464 Inventors: M.E. Ventura, M.S. Dahanayake Publication date:l April 1999
Obtaining pure water from crude water Applicant: HVR Water Purification, Sweden An apparatus for obtaining pure water from crude water is covered by this patent. It includes an evaporator arrangement that has a first circuit for circulating crude water, a second circuit for circulating liquid coolant, and membrane elements for separating the circulating crude water from the circulating liquid coolant and for obtaining pure water from the crude water by means of membrane distillation through the medium of the membrane elements. Connected to the first circuit is one side of a heat exchanger for raising the temperature of the crude water before the water enters the evaporator arrangement. The apparatus also includes a heat pump for lowering the temperature of the liquid coolant before the coolant enters the evaporator arrangement. The high-temperature side of the heat pump is connected to the input side of the second circuit via the remaining side of the heat exchanger and a cooling device. The low temperature side of the heat pump is connected to the output side of the second circuit. Patent number." WO 99/15463 Inventor." R. Lysdn Publication date: 1 April 1999
Ordered mesoporous thin films Applicant." Sandia Corporation, USA This invention comprises a method of forming a family of supported films with a pore size of approximately 0.8-20 nm exhibiting highly ordered microstructures and porosity derived from an ordered micellar or liquid-crystalline organic-inorganic precursor structure that forms during film deposition. Optically transparent, 100-500 nm thick films exhibiting a unique range of microstructures and uni-modal pore sizes are formed in seconds in a continuous coating operation. Applications of these films include sensors, membranes, low dielectric
constant interlayers, anti-reflective coatings, and optical hosts. Patent number: WO 99/15280 Inventors: J.C. Brinker, M.T. Anderson, R. Ganguli, Y Lu Publication date: 1 April 1999
Heat-sterilisable membranes Applicant: Gambro Dialysatoren GmbH & Co KG, Germany Heat-sterilisable membranes are disclosed comprising at least two hydrophobic polymers which are normally immiscible with each other, and in which at least one of the hydrophobic polynrers is normally unstable under sterilisation conditions while at least one of the other hydrophobic polymers is normally stable at sterilisation conditions, and in which at least two hydrophobic polymers are compatible with each other so that the membrane formed therefrom is stable under such sterilisation conditions. Patent number: US 5891338 Inventors: C.M. Bell, R. Buck, B. Thome, M. Storr, H. Gohl Publication date: 6 April 1999
Fluid separation Applicant: Praxair Technology Inc, USA Improved anisotropic fluid separation membranes are prepared from blends of polymers with surface energy differences. The membranes are formulated by processes wherein a low surface energy polymer with desirable fluid separation and permeation characteristics is preferentially concentrated in the surface discriminating layer of the membrane. Patent number: US 5891572 Inventors: J.T. Macheras, B. Bikson, J.K. Nelson Publication date: 6 April 1999
Porous membrane comprising ceramics and plastics Applicant: NGK Insulators Ltd, Japan This patent covers a porous membrane comprising aggregate particles of a ceramic bonded to one another with the aid of a binder comprising a plastic. The aspect ratio of the aggregate particle is 2.0 or less, and the content of the aggregate particles in the porous membrane is 60% to 99 % by volume. The porous membrane can be easily prepared at low cost and permits improving the productivity. Furthermore, the porous membrane significantly has features of ceramics in terms of strength and corrosion resistance and permits precise control of the pore diameter which is an important factor of separation membranes and filtration membranes. Patent number: WO 99/16603 Inventors: T. Suzuki, T. Otagiri Publication date: 8 April 1999
Using crossflow filtration to make polyester Applicant: Mobile Process Technology, USA This invention covers an improved process for the manufacture of polyester resin from the esterification of an aromatic acid with a glycol. This is followed by poly-condensation in the presence of a metal oxide catalyst in which a spent glycol stream is removed during the course of the poly-condensation reaction along with insolubles, large particulates, low molecular weight oligomers, metal oxide catalyst, cation impurities and anion impurities, and trace amounts of other impurities in which the temperature of the spent glycol stream is increased to maintain the monomer dissolved in solution while passing the spent glycol stream to a crossflow membrane filter with sufficient fluid velocity across the crossflow membrane filter to maintain turbulent flow. The glycol permeate is recycled to the esterification process while the concentrated insolubles are separated from the purged retentate. Patent number: WO 99/16537 Inventors: M.D. Kelly, J.C. Dougherty Publication date: 8 April 1999
Composite hollow fibre membrane Applicant: Mitsubishi Rayon Co, Japan A composite hollow fibre membrane having a composite structure comprising a thin homogeneous film sandwiched between porous support layers is the subject of this patent. The ratio of the oxygen permeability to the nitrogen permeability of the film is 1.1 or higher and the change of that ratio through immersion in a chemical in accordance with J1S K 7114 is within +10 %, and which does not leak the chemical at all even when degassed. Patent number: WO 99/17866 Inventors: M. Uenishi, N. Fukushima Publication date: 15 April 1999
Separating groups of elements from aqueous solutions Applicant: Sartorius AG, Germany This invention relates to a method for separating specifc groups of elements, especially groups of various metals and semi-metals, from aqueous solutions using ion-exchange membranes. According to the invention, three groups comprising at least 65 elements, especially metals and semi-metals, are separated by filtering aqueous solutions of the same through ion-exchange membranes. A first group is reversibly bonded to the anion-exchange membranes and a second group is reversibly bonded to the cation-exchange membranes, while a third group passes through both ionexchange membranes without bonding. At least 80% of each of the metals and senti-metals of the first two groups is bonded to the membranes. The invention is suitable for use in
MembraneTechnologyNo. 110
Obtaining pure water from crude water Applicant: HVR Water Purification, Sweden An apparatus for obtaining pure water from crude water is covered by this patent. It includes an evaporator arrangement that has a first circuit for circulating crude water, a second circuit for circulating liquid coolant, and membrane elements for separating the circulating crude water from the circulating liquid coolant and for obtaining pure water from the crude water by means of membrane distillation through the medium of the membrane elements. Connected to the first circuit is one side of a heat exchanger for raising the temperature of the crude water before the water enters the evaporator arrangement. The apparatus also includes a heat pump for lowering the temperature of the liquid coolant before the coolant enters the evaporator arrangement. The high-temperature side of the heat pump is connected to the input side of the second circuit via the remaining side of the heat exchanger and a cooling device. The low temperature side of the heat pump is connected to the output side of the second circuit. Patent number." WO 99/15463 Inventor." R. Lysdn Publication date: 1 April 1999
Ordered mesoporous thin films Applicant." Sandia Corporation, USA This invention comprises a method of forming a family of supported films with a pore size of approximately 0.8-20 nm exhibiting highly ordered microstructures and porosity derived from an ordered micellar or liquid-crystalline organic-inorganic precursor structure that forms during film deposition. Optically transparent, 100-500 nm thick films exhibiting a unique range of microstructures and uni-modal pore sizes are formed in seconds in a continuous coating operation. Applications of these films include sensors, membranes, low dielectric
constant interlayers, anti-reflective coatings, and optical hosts. Patent number: WO 99/15280 Inventors: J.C. Brinker, M.T. Anderson, R. Ganguli, Y Lu Publication date: 1 April 1999
Heat-sterilisable membranes Applicant: Gambro Dialysatoren GmbH & Co KG, Germany Heat-sterilisable membranes are disclosed comprising at least two hydrophobic polymers which are normally immiscible with each other, and in which at least one of the hydrophobic polynrers is normally unstable under sterilisation conditions while at least one of the other hydrophobic polymers is normally stable at sterilisation conditions, and in which at least two hydrophobic polymers are compatible with each other so that the membrane formed therefrom is stable under such sterilisation conditions. Patent number: US 5891338 Inventors: C.M. Bell, R. Buck, B. Thome, M. Storr, H. Gohl Publication date: 6 April 1999
Fluid separation Applicant: Praxair Technology Inc, USA Improved anisotropic fluid separation membranes are prepared from blends of polymers with surface energy differences. The membranes are formulated by processes wherein a low surface energy polymer with desirable fluid separation and permeation characteristics is preferentially concentrated in the surface discriminating layer of the membrane. Patent number: US 5891572 Inventors: J.T. Macheras, B. Bikson, J.K. Nelson Publication date: 6 April 1999
Porous membrane comprising ceramics and plastics Applicant: NGK Insulators Ltd, Japan This patent covers a porous membrane comprising aggregate particles of a ceramic bonded to one another with the aid of a binder comprising a plastic. The aspect ratio of the aggregate particle is 2.0 or less, and the content of the aggregate particles in the porous membrane is 60% to 99 % by volume. The porous membrane can be easily prepared at low cost and permits improving the productivity. Furthermore, the porous membrane significantly has features of ceramics in terms of strength and corrosion resistance and permits precise control of the pore diameter which is an important factor of separation membranes and filtration membranes. Patent number: WO 99/16603 Inventors: T. Suzuki, T. Otagiri Publication date: 8 April 1999
Using crossflow filtration to make polyester Applicant: Mobile Process Technology, USA This invention covers an improved process for the manufacture of polyester resin from the esterification of an aromatic acid with a glycol. This is followed by poly-condensation in the presence of a metal oxide catalyst in which a spent glycol stream is removed during the course of the poly-condensation reaction along with insolubles, large particulates, low molecular weight oligomers, metal oxide catalyst, cation impurities and anion impurities, and trace amounts of other impurities in which the temperature of the spent glycol stream is increased to maintain the monomer dissolved in solution while passing the spent glycol stream to a crossflow membrane filter with sufficient fluid velocity across the crossflow membrane filter to maintain turbulent flow. The glycol permeate is recycled to the esterification process while the concentrated insolubles are separated from the purged retentate. Patent number: WO 99/16537 Inventors: M.D. Kelly, J.C. Dougherty Publication date: 8 April 1999
Composite hollow fibre membrane Applicant: Mitsubishi Rayon Co, Japan A composite hollow fibre membrane having a composite structure comprising a thin homogeneous film sandwiched between porous support layers is the subject of this patent. The ratio of the oxygen permeability to the nitrogen permeability of the film is 1.1 or higher and the change of that ratio through immersion in a chemical in accordance with J1S K 7114 is within +10 %, and which does not leak the chemical at all even when degassed. Patent number: WO 99/17866 Inventors: M. Uenishi, N. Fukushima Publication date: 15 April 1999
Separating groups of elements from aqueous solutions Applicant: Sartorius AG, Germany This invention relates to a method for separating specifc groups of elements, especially groups of various metals and semi-metals, from aqueous solutions using ion-exchange membranes. According to the invention, three groups comprising at least 65 elements, especially metals and semi-metals, are separated by filtering aqueous solutions of the same through ion-exchange membranes. A first group is reversibly bonded to the anion-exchange membranes and a second group is reversibly bonded to the cation-exchange membranes, while a third group passes through both ionexchange membranes without bonding. At least 80% of each of the metals and senti-metals of the first two groups is bonded to the membranes. The invention is suitable for use in
MembraneTechnologyNo. 110