US3773634A - Control of an olyte-catholyte concentrations in membrane cells - Google Patents

Control of an olyte-catholyte concentrations in membrane cells Download PDF

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Publication number
US3773634A
US3773634A US00233129A US3773634DA US3773634A US 3773634 A US3773634 A US 3773634A US 00233129 A US00233129 A US 00233129A US 3773634D A US3773634D A US 3773634DA US 3773634 A US3773634 A US 3773634A
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catholyte
concentration
anolyte
membrane
range
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US00233129A
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A Stacey
R Dotson
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Diamond Shamrock Chemicals Co
Eltech Systems Corp
Diamond Shamrock Corp
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Diamond Shamrock Corp
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Assigned to ELTECH SYSTEMS CORPORATION reassignment ELTECH SYSTEMS CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: DIAMOND SHAMROCK CORPORATION, 717 N. HARWOOD STREET, DALLAS, TX 75201
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00—Electrolytic production of inorganic compounds or non-metals
    • C25B1/01—Products
    • C25B1/34—Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis
    • C25B1/46—Simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine, e.g. by chlor-alkali electrolysis in diaphragm cells

Definitions

  • ABSTRACT The electrolysis of aqueous sodium chloride in an electrolytic cell divided into anolyte and catholyte compartments by a hydraulically impervious cationpermselective membrane is improved, especially with respect to current efficiency, by operation at a sodium hydroxide concentration within the catholyte in the range of 31-43 percent, controlled by the maintenance of an average sodium chloride concentration in the anolyte within the range of 120-250 grams per liter, the only source of water to the catholyte compartment being that transported through the membrane.
  • saturated brine is fed to the anolyte compartment wherein chlorine is generated at the anode, the brine percolating through the diaphragm into the catholyte compartment wherein sodium hydroxide is produced in a concentration within the range of l l-l8 percent and contaminated.” with large amounts of sodium chloride.
  • This sodium chloride must then be separated from the caustic and the caustic in turn concentrated by evaporation toprovide a commercial product.
  • control of the sodium chloride concentration in the anolyte within the stated range results in maintaining the caustic concentration in the catholyte at an optimum value without necessity for the separate controlled addition of water to the catholyte.
  • a self-sustaining equilibrium is established and maintained between the anolyte and the catholyte resulting in consistent and efficient cell operation.
  • FIGURE is a graph relating sodium hydroxide concentration to current efficiency and showing a critical optimum value within the range of the present invention, the particular values being those determined under the operating parameters obtaining in the second production run of the Example.
  • the membrane cells to which the operational techniques of the present invention apply, as well as the other operating parameters, are for the most part conventional.
  • an enclosure is provided and dividedinto two compartments by the membrane material.
  • the catholyte compartment is disposed an appropriate cathode, generally a metallic material, such as iron.
  • the other compartment, the anolyte compartment contains the anode a conductive, electrolytically-active material, such as graphite or, more desirably, a dimensionally stable anode, e.g., a titanium substrate bearing a coating of a precious metal; precious metal oxide or other electrolyticallyactive corrosion-resistant material.
  • the anolyte compartment is provided'with an outlet for generated chlorine gas, an inlet for brine solution and an outlet for depleted brine.
  • the catholyte compartment will have outlets for liquid and gaseous products and, generally, an inlet through which water and/or sodium hydroxide solution may be added initially.
  • a direct currrnt is passed between the electrodes, causing the generation of chlorine at the anode andthe selective transport of hydrated sodium ions across the membrane into the catholyte compartment where they combine with hydroxide ions formed at the cathode by the electrolysis of water, hydrogen gas being liberated.
  • a cell employing any permselective cationexchange membrane electrolytically conductive in the hydrated'state obtaining under cell conditions and useful in the electrolysis of brine is improved by the operational-techniques characteristic of the present invention.
  • these membranes are sulfonated materials based upon a chemically-resistant highly crosslinked polymer backbone, such as a divinylbenzeneacrylic acid copolymer, polyethylene, divinylbenzenepolystyrene copolymers, polyvinylfluorocarbon ethers and the like.
  • Particularly preferred at this time, because oftheirapparentsuperiority in a membrane cell for the electrolysis of sodium chloride are the membranes manufactured and sold by the E. l.
  • a useful membrane comprises a chemically and mechanically resistant polymer matrix or backbone to which are attached, in an extremelyv stable fashion, highly-electronegative exchange sites, such as sulfonic, phosphonic or carboxylic acid groups.
  • highly-electronegative exchange sites such as sulfonic, phosphonic or carboxylic acid groups.
  • thicknesses of membranes of the foregoing type employed are generally on the order of 4-20 mils. Greater thicknesses are useful, however, any incidential advantage in the use of such thicknesses is more than offset by the added cost of the material. With thicknesses of less than 10 mils, mechanical support, e.g., in the nature ofa woven Teflon screen, is often advantageous.
  • Exemplary of other non-critical process parameters are operating temperatures within the range of l00C., feed brine pH within the range of 1.0-6.0 and anode current densities on the order of 1.0-5.0 amperes per square inch.
  • the invention contemplates that once there is established a caustic concentration corresponding to the optimum sodium hydroxide-based current efficiency obtainable with the permselective membrane, this concentration is maintained by control of the anolyte. Such control ensures that the proper critical amount of hydrated sodium ions will be transported by the membrane to the catholyte, said transport being the only source of water to the catholyte.
  • the range of sodium hydroxide concentrations in the catholyte which corresponds to optimum current efficiency is quite narrow, generally within 31-43 percent by weight, especially 35-39 percent, and peaking in the area of 36-38 percent. At lesser concentrations, a much lower current efficiency is realized and, in any event, more water must be evaporated from the catholyte to yield a commercial product. At higher concentrations, current efficiency again sharply decreases, cell voltage increases and the catholyte product rapidly becomes too viscous to handle, often setting-up into a hard mass at concentrations greater than 55 percent.
  • the means of maintaining the caustic concentration at the desired level is to be found, according to the invention, in the concentration of sodium chloride present in the anolyte compartment.
  • This concentration is considerably lower than heretofore employed for optimum diaphragm or membrane cell operation and is generally within the range of 120-250, especially 150-220, grams per liter.
  • the concentration of sodium chloride in the anolyte is not to be confused with the feed brine concentration since other factors, e.g., depletion and flow rate, must be taken into account.
  • the concentration referred to is that within the anolyte compartment, often conveniently measured by determining the salt content of the effluent from this compartment.
  • the means of initially establishing the sodium hydroxide concentration within the desired range, particularly at about 36-38 percent, are quite varied.
  • the catholyte compartment may be initially charged with a caustic solution of the desired concentration. Thereafter, upon imposition of an electrolyzing current and establishment of the appropriate brine concentration, the caustic concentration will remain at substantially the same value throughout operation. Alternately, operation may be begun with water in the catholyte compartment and electrolysis continued, albeit inefficiently, until the appropriate caustic value is reached.
  • the catholyte compartment initially contains a 36 percent solution of caustic.
  • a sodium chloride solution having a pH of 3.0, is fed to the anolyte compartment wherein electrolysis is conducted at an applied anode current density of l a.s.i. and a cell temperature of about C.
  • the feed brine contains 303 grams per liter of sodium chloride and is introduced to the anolyte compartment at a rate of about 358 milliliters per minute, giving an average anolyte concentration of 287 grams per liter of sodium chloride.
  • anolyte overflows at a rate of about 340 mls. per minute while the flow from the catholyte compartment is on the order of 3.4 mls. per minute.
  • the sodium hydroxide concentration in the catholyte rises rapidly, at a rate of about 4 percent per day, the majority of the run being within the range of 41-54 percent sodium hydroxide. The average current efficiency for this period of operation is 40.4 percent.
  • the second production run is identical, with the exception that a brine having a concentration of 160 grams per liter sodium chloride is fed to the anolyte compartment at the rate of about 300 milliliters per minute, resulting in an average anolyte concentration of 134 grams per liter sodium chloride. Under these conditions an anolyte overflow of 276 mls. per minute and a catholyte flow rate of about 12 mls. per minute are measured.
  • the product is a constant 36 percent sodium hydroxide solution with the cell operating at a current efficiency of 79.8 percent.

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  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)
US00233129A 1972-03-09 1972-03-09 Control of an olyte-catholyte concentrations in membrane cells Expired - Lifetime US3773634A (en)

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US23312972A 1972-03-09 1972-03-09
US31296572A 1972-12-07 1972-12-07

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US (1) US3773634A (enrdf_load_stackoverflow)
JP (1) JPS5210678B2 (enrdf_load_stackoverflow)
AR (1) AR201101A1 (enrdf_load_stackoverflow)
AT (1) AT320679B (enrdf_load_stackoverflow)
BE (1) BE796440A (enrdf_load_stackoverflow)
CA (1) CA1003781A (enrdf_load_stackoverflow)
DE (1) DE2311556C3 (enrdf_load_stackoverflow)
ES (1) ES412416A1 (enrdf_load_stackoverflow)
FR (1) FR2175173B1 (enrdf_load_stackoverflow)
GB (1) GB1369576A (enrdf_load_stackoverflow)
IL (1) IL41733A (enrdf_load_stackoverflow)
IT (1) IT979771B (enrdf_load_stackoverflow)
LU (1) LU67180A1 (enrdf_load_stackoverflow)
NL (1) NL162435C (enrdf_load_stackoverflow)
SE (1) SE381892B (enrdf_load_stackoverflow)

Cited By (35)

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US3899403A (en) * 1973-11-01 1975-08-12 Hooker Chemicals Plastics Corp Electrolytic method of making concentrated hydroxide solutions by sequential use of 3-compartment and 2-compartment electrolytic cells having separating compartment walls of particular cation-active permselective membranes
JPS50120492A (enrdf_load_stackoverflow) * 1974-03-07 1975-09-20
US3948737A (en) * 1971-12-27 1976-04-06 Hooker Chemicals & Plastics Corporation Process for electrolysis of brine
US3954579A (en) * 1973-11-01 1976-05-04 Hooker Chemicals & Plastics Corporation Electrolytic method for the simultaneous manufacture of concentrated and dilute aqueous hydroxide solutions
US3959095A (en) * 1975-01-31 1976-05-25 Hooker Chemicals & Plastics Corporation Method of operating a three compartment electrolytic cell for the production of alkali metal hydroxides
US3974047A (en) * 1975-06-02 1976-08-10 The B. F. Goodrich Company Electrolytic cation exchange process for conjoint manufacture of chlorine and phosphate salts
US3976549A (en) * 1973-02-26 1976-08-24 Hooker Chemicals & Plastics Corporation Electrolysis method
US3985631A (en) * 1975-08-13 1976-10-12 Diamond Shamrock Corporation Pretreatment and start-up of electrolytic cell membranes
US4036714A (en) * 1972-10-19 1977-07-19 E. I. Du Pont De Nemours And Company, Inc. Electrolytic cells and processes
US4040919A (en) * 1974-10-29 1977-08-09 Hooker Chemicals & Plastics Corporation Voltage reduction of membrane cell for the electrolysis of brine
US4040935A (en) * 1975-04-11 1977-08-09 Basf Wyandotte Corporation Protective covering for electrolytic filter press cell frames
US4055475A (en) * 1976-02-24 1977-10-25 Olin Corporation Method for operating electrolytic diaphragm cells
US4061550A (en) * 1973-08-15 1977-12-06 Hooker Chemicals & Plastics Corporation Process for electrolysis
US4062743A (en) * 1975-12-22 1977-12-13 Ahn Byung K Electrolytic process for potassium hydroxide
JPS5337198A (en) * 1977-07-15 1978-04-06 Asahi Chem Ind Co Ltd Electrolytic method of sodium chloride
US4100050A (en) * 1973-11-29 1978-07-11 Hooker Chemicals & Plastics Corp. Coating metal anodes to decrease consumption rates
US4107005A (en) * 1974-12-23 1978-08-15 Hooker Chemicals & Plastics Corporation Process for electrolysing sodium chloride or hydrochloric acid, an and electrolytic cell, employing trifluorostyrene sulfonic acid membrane
US4110265A (en) * 1977-03-01 1978-08-29 Ionics Inc. Ion exchange membranes based upon polyphenylene sulfide
US4124477A (en) * 1975-05-05 1978-11-07 Hooker Chemicals & Plastics Corp. Electrolytic cell utilizing pretreated semi-permeable membranes
US4127457A (en) * 1976-12-17 1978-11-28 Basf Wyandotte Corporation Method of reducing chlorate formation in a chlor-alkali electrolytic cell
US4178218A (en) * 1974-03-07 1979-12-11 Asahi Kasei Kogyo Kabushiki Kaisha Cation exchange membrane and use thereof in the electrolysis of sodium chloride
US4276130A (en) * 1975-07-11 1981-06-30 Asahi Kasei Kogyo Kabushiki Kaisha Process for the production of high purity aqueous alkali hydroxide solution
US4323434A (en) * 1979-02-16 1982-04-06 Asahi Kasei Kogyo Kabushiki Kaisha Process for electrolysis of alkali chloride
US4488947A (en) * 1983-06-08 1984-12-18 Olin Corporation Process of operation of catholyteless membrane electrolytic cell
US4532018A (en) * 1983-09-06 1985-07-30 Olin Corporation Chlor-alkali cell control system based on mass flow analysis
US4548694A (en) * 1983-06-08 1985-10-22 Olin Corporation Catholyteless membrane electrolytic cell
US4592822A (en) * 1978-07-27 1986-06-03 Oronzio Denora Impianti Elettrochimici S.P.A. Electrolysis cell
US20080029404A1 (en) * 2006-05-18 2008-02-07 Bayer Material Science Ag Processes for the production of chlorine from hydrogen chloride and oxygen
US20080053836A1 (en) * 2006-09-02 2008-03-06 Bayer Material Science Ag Process for the production of diaryl carbonates and treatment of alkalichloride solutions resulting therefrom
DE102007058701A1 (de) 2007-12-06 2009-06-10 Bayer Materialscience Ag Verfahren zur Herstellung von Diarylcarbonat
US20090215977A1 (en) * 2008-02-27 2009-08-27 Bayer Materialscience Ag Process for the preparation of polycarbonate
US7776204B2 (en) 2004-06-22 2010-08-17 Chlorine Engineers Corp., Ltd. Ion exchange membrane electrolytic process
EP2241550A1 (de) 2009-04-17 2010-10-20 Bayer MaterialScience AG Verfahren zur Herstellung von Diarylcarbonat
DE102009023940A1 (de) 2009-06-04 2010-12-09 Bayer Materialscience Ag Verfahren zur Herstellung von Polycarbonat
EP4083106A1 (de) 2021-04-30 2022-11-02 Covestro Deutschland AG Verfahren zur herstellung von polycarbonat mit verbesserter nachhaltigkeit

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5154082A (ja) * 1974-11-08 1976-05-12 Asahi Glass Co Ltd Yoionkokanmaku
JPS5950753B2 (ja) * 1975-05-30 1984-12-10 旭硝子株式会社 水酸化ナトリウムの製造方法
IT1061477B (it) * 1975-07-09 1983-02-28 Asahi Chemical Ind Membrana scambiatrice di cationi sua preparazione e suo impiego
JPS52167664U (enrdf_load_stackoverflow) * 1976-06-14 1977-12-19
US4056448A (en) * 1976-12-17 1977-11-01 Diamond Shamrock Corporation Process for brine membrane cell operation with external caustic and nacl concentration control
JPS5547151A (en) * 1979-06-04 1980-04-03 Asahi Chem Ind Co Ltd Cation exchange membrane
JPS5547152A (en) * 1979-08-20 1980-04-03 Asahi Chem Ind Co Ltd New type cation exchange membrane
US11142237B2 (en) 2020-01-14 2021-10-12 Honda Motor Co., Ltd. Tilt steering assembly for a vehicle

Family Cites Families (2)

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Publication number Priority date Publication date Assignee Title
GB955307A (en) * 1962-01-26 1964-04-15 Pittsburgh Plate Glass Co Improvements in and relating to the electrolytic production of alkali metal hydroxide and chlorine
US3616328A (en) * 1968-09-23 1971-10-26 Hooker Chemical Corp Catholyte recirculation in diaphragm chlor-alkali cells

Cited By (58)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3948737A (en) * 1971-12-27 1976-04-06 Hooker Chemicals & Plastics Corporation Process for electrolysis of brine
US4036714A (en) * 1972-10-19 1977-07-19 E. I. Du Pont De Nemours And Company, Inc. Electrolytic cells and processes
US3976549A (en) * 1973-02-26 1976-08-24 Hooker Chemicals & Plastics Corporation Electrolysis method
US4062753A (en) * 1973-02-26 1977-12-13 Hooker Chemicals & Plastics Corporation Electrolysis method and apparatus
US4061550A (en) * 1973-08-15 1977-12-06 Hooker Chemicals & Plastics Corporation Process for electrolysis
US3954579A (en) * 1973-11-01 1976-05-04 Hooker Chemicals & Plastics Corporation Electrolytic method for the simultaneous manufacture of concentrated and dilute aqueous hydroxide solutions
US3899403A (en) * 1973-11-01 1975-08-12 Hooker Chemicals Plastics Corp Electrolytic method of making concentrated hydroxide solutions by sequential use of 3-compartment and 2-compartment electrolytic cells having separating compartment walls of particular cation-active permselective membranes
US4100050A (en) * 1973-11-29 1978-07-11 Hooker Chemicals & Plastics Corp. Coating metal anodes to decrease consumption rates
DE2560241C2 (de) * 1974-03-07 1982-07-01 Asahi Kasei Kogyo K.K., Osaka Verfahren zur Elektrolyse von Natriumchlorid
US4178218A (en) * 1974-03-07 1979-12-11 Asahi Kasei Kogyo Kabushiki Kaisha Cation exchange membrane and use thereof in the electrolysis of sodium chloride
DE2560151B1 (de) * 1974-03-07 1980-11-27 Asahi Chemical Ind Fluorkohlenstoffpolymerisate und funktionelle Gruppen enthaltende,dichte Kationenaustauschermembran fuer die Elektrolyse einer waessrigen Natriumchloridloesung
US4683041A (en) * 1974-03-07 1987-07-28 Asahi Kasei Kogyo Kabushiki Kaisha Process for electrolysis of sodium chloride
DE2560232B2 (de) * 1974-03-07 1981-08-06 Asahi Kasei Kogyo K.K., Osaka Fluorkohlenstoffpulymerisate und funktionelle Gruppen enthaltende, dichte Kationenaustauschermembran für die Elektrolyse einer wässrigen Natriumchloridlösung
JPS50120492A (enrdf_load_stackoverflow) * 1974-03-07 1975-09-20
DE2510071B2 (de) 1974-03-07 1980-11-27 Asahi Kasei Kogyo K.K., Osaka (Japan) Verfahren zur Elektrolyse von Natriumchlorid
US4683040A (en) * 1974-03-07 1987-07-28 Asahi Kasei Kogyo Kabushiki Kaisha Process for electrolysis of sodium chloride
US4357218A (en) * 1974-03-07 1982-11-02 Asahi Kasei Kogyo Kabushiki Kaisha Cation exchange membrane and use thereof in the electrolysis of sodium chloride
US4040919A (en) * 1974-10-29 1977-08-09 Hooker Chemicals & Plastics Corporation Voltage reduction of membrane cell for the electrolysis of brine
US4107005A (en) * 1974-12-23 1978-08-15 Hooker Chemicals & Plastics Corporation Process for electrolysing sodium chloride or hydrochloric acid, an and electrolytic cell, employing trifluorostyrene sulfonic acid membrane
US3959095A (en) * 1975-01-31 1976-05-25 Hooker Chemicals & Plastics Corporation Method of operating a three compartment electrolytic cell for the production of alkali metal hydroxides
US4040935A (en) * 1975-04-11 1977-08-09 Basf Wyandotte Corporation Protective covering for electrolytic filter press cell frames
US4124477A (en) * 1975-05-05 1978-11-07 Hooker Chemicals & Plastics Corp. Electrolytic cell utilizing pretreated semi-permeable membranes
US3974047A (en) * 1975-06-02 1976-08-10 The B. F. Goodrich Company Electrolytic cation exchange process for conjoint manufacture of chlorine and phosphate salts
US4276130A (en) * 1975-07-11 1981-06-30 Asahi Kasei Kogyo Kabushiki Kaisha Process for the production of high purity aqueous alkali hydroxide solution
US3985631A (en) * 1975-08-13 1976-10-12 Diamond Shamrock Corporation Pretreatment and start-up of electrolytic cell membranes
US4062743A (en) * 1975-12-22 1977-12-13 Ahn Byung K Electrolytic process for potassium hydroxide
US4055475A (en) * 1976-02-24 1977-10-25 Olin Corporation Method for operating electrolytic diaphragm cells
US4127457A (en) * 1976-12-17 1978-11-28 Basf Wyandotte Corporation Method of reducing chlorate formation in a chlor-alkali electrolytic cell
US4110265A (en) * 1977-03-01 1978-08-29 Ionics Inc. Ion exchange membranes based upon polyphenylene sulfide
JPS5337198A (en) * 1977-07-15 1978-04-06 Asahi Chem Ind Co Ltd Electrolytic method of sodium chloride
US4592822A (en) * 1978-07-27 1986-06-03 Oronzio Denora Impianti Elettrochimici S.P.A. Electrolysis cell
US4323434A (en) * 1979-02-16 1982-04-06 Asahi Kasei Kogyo Kabushiki Kaisha Process for electrolysis of alkali chloride
US4488947A (en) * 1983-06-08 1984-12-18 Olin Corporation Process of operation of catholyteless membrane electrolytic cell
US4548694A (en) * 1983-06-08 1985-10-22 Olin Corporation Catholyteless membrane electrolytic cell
US4532018A (en) * 1983-09-06 1985-07-30 Olin Corporation Chlor-alkali cell control system based on mass flow analysis
EP0136806A3 (en) * 1983-09-06 1987-08-26 Olin Corporation Chlor-alkali cell control system based on mass flow analysis
US7776204B2 (en) 2004-06-22 2010-08-17 Chlorine Engineers Corp., Ltd. Ion exchange membrane electrolytic process
US20080029404A1 (en) * 2006-05-18 2008-02-07 Bayer Material Science Ag Processes for the production of chlorine from hydrogen chloride and oxygen
US9447510B2 (en) 2006-05-18 2016-09-20 Covestro Deutschland Ag Processes for the production of chlorine from hydrogen chloride and oxygen
US20080053836A1 (en) * 2006-09-02 2008-03-06 Bayer Material Science Ag Process for the production of diaryl carbonates and treatment of alkalichloride solutions resulting therefrom
DE102007058701A1 (de) 2007-12-06 2009-06-10 Bayer Materialscience Ag Verfahren zur Herstellung von Diarylcarbonat
US20090173636A1 (en) * 2007-12-06 2009-07-09 Bayer Materialscience Ag Process for production of diaryl carbonate
US8518231B2 (en) 2007-12-06 2013-08-27 Bayer Intellectual Property Gmbh Process for production of diaryl carbonate
US20110147229A1 (en) * 2007-12-06 2011-06-23 Bayer Materialscience Ag Process for production of diaryl carbonate
DE102008011473A1 (de) 2008-02-27 2009-09-03 Bayer Materialscience Ag Verfahren zur Herstellung von Polycarbonat
US7858727B2 (en) 2008-02-27 2010-12-28 Bayer Materialscience Ag Process for the preparation of polycarbonate
US20090215977A1 (en) * 2008-02-27 2009-08-27 Bayer Materialscience Ag Process for the preparation of polycarbonate
EP2096131A1 (de) 2008-02-27 2009-09-02 Bayer MaterialScience AG Verfahren zur Herstellung von Polycarbonat
US8882984B2 (en) 2009-04-17 2014-11-11 Bayer MaerialScience AG Process for preparing diaryl carbonate
EP2241550A1 (de) 2009-04-17 2010-10-20 Bayer MaterialScience AG Verfahren zur Herstellung von Diarylcarbonat
DE102009017862A1 (de) 2009-04-17 2010-10-21 Bayer Materialscience Ag Verfahren zur Herstellung von Diarylcarbonat
US20100286431A1 (en) * 2009-04-17 2010-11-11 Bayer Materialscience Ag Process for preparing diaryl carbonate
US20100324256A1 (en) * 2009-06-04 2010-12-23 Bayer Materialsscience Ag Process for producing polycarbonate
EP2286898A1 (de) 2009-06-04 2011-02-23 Bayer MaterialScience AG Verfahren zur Herstellung von Polycarbonat
US8106144B2 (en) 2009-06-04 2012-01-31 Bayer Materialscience Ag Process for producing polycarbonate
DE102009023940A1 (de) 2009-06-04 2010-12-09 Bayer Materialscience Ag Verfahren zur Herstellung von Polycarbonat
EP4083106A1 (de) 2021-04-30 2022-11-02 Covestro Deutschland AG Verfahren zur herstellung von polycarbonat mit verbesserter nachhaltigkeit
WO2022229245A1 (de) 2021-04-30 2022-11-03 Covestro Deutschland Ag Verfahren zur herstellung von polycarbonat mit verbesserter nachhaltigkeit

Also Published As

Publication number Publication date
NL7303297A (enrdf_load_stackoverflow) 1973-09-11
IL41733A0 (en) 1973-06-29
NL162435B (nl) 1979-12-17
DE2311556B2 (de) 1977-08-18
GB1369576A (en) 1974-10-09
DE2311556A1 (de) 1973-09-13
ES412416A1 (es) 1976-05-01
JPS5210678B2 (enrdf_load_stackoverflow) 1977-03-25
FR2175173B1 (enrdf_load_stackoverflow) 1976-11-05
JPS491497A (enrdf_load_stackoverflow) 1974-01-08
AR201101A1 (es) 1975-02-14
AT320679B (de) 1975-02-25
DE2311556C3 (de) 1982-05-19
NL162435C (nl) 1980-05-16
LU67180A1 (enrdf_load_stackoverflow) 1974-03-14
IT979771B (it) 1974-09-30
FR2175173A1 (enrdf_load_stackoverflow) 1973-10-19
BE796440A (fr) 1973-09-10
IL41733A (en) 1976-02-29
SE381892B (sv) 1975-12-22
CA1003781A (en) 1977-01-18

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