- Email: [email protected]
Filtering aqueous reaction mixtures
PATENTS
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and water dissociation in bipolar membranes, jr. of Membrane Science 125(1) 123-142. 5. Smith, J.R., Simons, R. and Weidenhaun, J. (1998) The low frequency conductance of bipolar membranes demonstrates the presence of a depletion layer, J. of Membrane Science 140(2) 155-164. 6. Iler, R.K. (1979) The chemistry of silica (Wiley).
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Even when the current density reaches 750 mA/cm 2, the membrane voltage is not higher than about 7-8 V. Figure 4 shows the durability of the developed membrane. While the voltage of a bipolar membrane (with the anion-exchange layer cast on a cation-exchange membrane after simply roughening the surface) reaches 2 V in a matter of a few days, the newly developed membrane has improved the time to reach the same voltage by about 35 days.
Conclusions A membrane with low initial voltage and high durability can be achieved by increasing the contacting specific surface area between the cationexchange and anion-exchange layers. The bipolar membranes which have been developed, based on
Patents Filtering aqueous reaction mixtures Applicant: BASF, Germany This invention relates to a method for filtering an aqueous reaction mixture that results from the production of hydroxylamine using a carrier catalyst which includes solid catalyst particles. The reaction mixture is subjected to cross-flow filtration on a membrane which consists of polyethylene, polypropylene, polyamide, PTFE, PVDF, polysulfone or a co-polymer of these. Patent number: W O 01/07362 Inventors: S. Bitterlich, H. Voss, H.J. Wilfinger, M. Bender Publication date: 1 February 2001
Membrane separation for metal complex catalysts Applicant: Union Carbide Chemicals & Plastics Technology, USA
Membrane Technology No. 135
For more information, contact: 1. Aritomi, S. Nago or F.Hanada,TokuyamaCorporation,TsukubaResearch
Laboratory,40 Wadai,Tsukuba,Ibaraki300-4247, Japan.Tel:+81 298 64 6041, Fax:+81 298 6045, Email: [email protected]
the findings described in this article, have excellent electrochemical properties and durability, compared with those of conventional membranes.
References I. Simons, R. and Khanarian, G. (1978) Water dissociation in bipolar membranes: Experiments and theory, J. of Membrane Biol. 38 11-30. 2. Simons, R. (1984) Electric field effects on proton transfer between ionizable groups and water in ion exchange membranes, Electrochimica Acta 29 151-158. 3. Ramirez, P., Rapp, H.-J., Reichle, S., Strathmann, H. and Mafe, S. (1992) Currentvoltage curves of bipolar membranes, J. ofi Applied Physics72(1) 259. 4. Strathmann, H., Krol. J.J., Rapp, H.-J. and Eigenberger, G. (1997) Limiting current density
This patent describes a process for separating a metal complex catalyst and any free ligand which may be present, from a homogeneous organic synthesis reaction-mixture using subnanoporous, chemically stable membranes. These have discrete pores which allow organic products and by-products to pass through the membrane as permeate while retaining substantially all of the metal complex catalyst and free ligand, if any, as retentate. Patent number: W O 01/07157 Inventors:J.E Miller, J.A. Rodberg, B.M. Roesch, G.E. Keller, L.E. Curry, P.E Bryan, J.E. Davis, J.C. Hatfield Publication date." 1 February 2001
Membrane filtering device Applicant: Prime Water Systems, Germany This invention covers a filtering device which comprises inlet and outlet connections, and a cylindrical filter connected to the inlet. This filter comprises a cavity extending along its cylinder axis. A filtration membrane
module is connected to the outlet, which is at least partially accommodated in the cavity of the filter - - the filter and the filtration membrane module are connected in series, and comprise a bundle of capillary filtration membranes whose open ends connect to the outlet. The exterior cylinder mantle of the filter forms an inlet, and the interior mantle of the filter, enclosing the cavity surrounding the cylinder axis, forms an outlet for the filter. The filter comprises a moulded block of activated charcoal. The membrane module comprises a perforated tube housing surrounding the capillary membranes, and positioned substantially free from the interior mantle of the filter surrounding the cavity. A felt-like filter folded in concertina fashion is provided around the block of activated charcoal as a filtering stage, with the folds parallel to the cylinder axis. Patent number."WO 01/07151 Inventors."J.J. Scharstuhl, E. Scharstuhl Publication date: 1 February 2001
@
3.0 2.5 CD 2.0
/
o cD c--
1.5
S
Improved membrane
and water dissociation in bipolar membranes, jr. of Membrane Science 125(1) 123-142. 5. Smith, J.R., Simons, R. and Weidenhaun, J. (1998) The low frequency conductance of bipolar membranes demonstrates the presence of a depletion layer, J. of Membrane Science 140(2) 155-164. 6. Iler, R.K. (1979) The chemistry of silica (Wiley).
1.0
E 0.5 0
i 10
2r0
I 30
Day
Even when the current density reaches 750 mA/cm 2, the membrane voltage is not higher than about 7-8 V. Figure 4 shows the durability of the developed membrane. While the voltage of a bipolar membrane (with the anion-exchange layer cast on a cation-exchange membrane after simply roughening the surface) reaches 2 V in a matter of a few days, the newly developed membrane has improved the time to reach the same voltage by about 35 days.
Conclusions A membrane with low initial voltage and high durability can be achieved by increasing the contacting specific surface area between the cationexchange and anion-exchange layers. The bipolar membranes which have been developed, based on
Patents Filtering aqueous reaction mixtures Applicant: BASF, Germany This invention relates to a method for filtering an aqueous reaction mixture that results from the production of hydroxylamine using a carrier catalyst which includes solid catalyst particles. The reaction mixture is subjected to cross-flow filtration on a membrane which consists of polyethylene, polypropylene, polyamide, PTFE, PVDF, polysulfone or a co-polymer of these. Patent number: W O 01/07362 Inventors: S. Bitterlich, H. Voss, H.J. Wilfinger, M. Bender Publication date: 1 February 2001
Membrane separation for metal complex catalysts Applicant: Union Carbide Chemicals & Plastics Technology, USA
Membrane Technology No. 135
For more information, contact: 1. Aritomi, S. Nago or F.Hanada,TokuyamaCorporation,TsukubaResearch
Laboratory,40 Wadai,Tsukuba,Ibaraki300-4247, Japan.Tel:+81 298 64 6041, Fax:+81 298 6045, Email: [email protected]
the findings described in this article, have excellent electrochemical properties and durability, compared with those of conventional membranes.
References I. Simons, R. and Khanarian, G. (1978) Water dissociation in bipolar membranes: Experiments and theory, J. of Membrane Biol. 38 11-30. 2. Simons, R. (1984) Electric field effects on proton transfer between ionizable groups and water in ion exchange membranes, Electrochimica Acta 29 151-158. 3. Ramirez, P., Rapp, H.-J., Reichle, S., Strathmann, H. and Mafe, S. (1992) Currentvoltage curves of bipolar membranes, J. ofi Applied Physics72(1) 259. 4. Strathmann, H., Krol. J.J., Rapp, H.-J. and Eigenberger, G. (1997) Limiting current density
This patent describes a process for separating a metal complex catalyst and any free ligand which may be present, from a homogeneous organic synthesis reaction-mixture using subnanoporous, chemically stable membranes. These have discrete pores which allow organic products and by-products to pass through the membrane as permeate while retaining substantially all of the metal complex catalyst and free ligand, if any, as retentate. Patent number: W O 01/07157 Inventors:J.E Miller, J.A. Rodberg, B.M. Roesch, G.E. Keller, L.E. Curry, P.E Bryan, J.E. Davis, J.C. Hatfield Publication date." 1 February 2001
Membrane filtering device Applicant: Prime Water Systems, Germany This invention covers a filtering device which comprises inlet and outlet connections, and a cylindrical filter connected to the inlet. This filter comprises a cavity extending along its cylinder axis. A filtration membrane
module is connected to the outlet, which is at least partially accommodated in the cavity of the filter - - the filter and the filtration membrane module are connected in series, and comprise a bundle of capillary filtration membranes whose open ends connect to the outlet. The exterior cylinder mantle of the filter forms an inlet, and the interior mantle of the filter, enclosing the cavity surrounding the cylinder axis, forms an outlet for the filter. The filter comprises a moulded block of activated charcoal. The membrane module comprises a perforated tube housing surrounding the capillary membranes, and positioned substantially free from the interior mantle of the filter surrounding the cavity. A felt-like filter folded in concertina fashion is provided around the block of activated charcoal as a filtering stage, with the folds parallel to the cylinder axis. Patent number."WO 01/07151 Inventors."J.J. Scharstuhl, E. Scharstuhl Publication date: 1 February 2001
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