US3773634A - Control of an olyte-catholyte concentrations in membrane cells - Google Patents
Control of an olyte-catholyte concentrations in membrane cells Download PDFInfo
- 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
- Authority
- US
- United States
- Prior art keywords
- catholyte
- concentration
- anolyte
- membrane
- range
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
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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.
Landscapes
- 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)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US23312972A | 1972-03-09 | 1972-03-09 | |
US31296572A | 1972-12-07 | 1972-12-07 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3773634A true US3773634A (en) | 1973-11-20 |
Family
ID=26926639
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US00233129A Expired - Lifetime US3773634A (en) | 1972-03-09 | 1972-03-09 | Control of an olyte-catholyte concentrations in membrane cells |
Country Status (15)
Country | Link |
---|---|
US (1) | US3773634A (de) |
JP (1) | JPS5210678B2 (de) |
AR (1) | AR201101A1 (de) |
AT (1) | AT320679B (de) |
BE (1) | BE796440A (de) |
CA (1) | CA1003781A (de) |
DE (1) | DE2311556C3 (de) |
ES (1) | ES412416A1 (de) |
FR (1) | FR2175173B1 (de) |
GB (1) | GB1369576A (de) |
IL (1) | IL41733A (de) |
IT (1) | IT979771B (de) |
LU (1) | LU67180A1 (de) |
NL (1) | NL162435C (de) |
SE (1) | SE381892B (de) |
Cited By (35)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
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 (de) * | 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 |
EP0136806A2 (de) * | 1983-09-06 | 1985-04-10 | Olin Corporation | Kontrollsystem für Chloralkali-Zelle auf Basis von Materialflussanalyse |
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)
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 (de) * | 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)
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 |
-
1972
- 1972-03-09 US US00233129A patent/US3773634A/en not_active Expired - Lifetime
-
1973
- 1973-03-06 CA CA165,361A patent/CA1003781A/en not_active Expired
- 1973-03-07 ES ES412416A patent/ES412416A1/es not_active Expired
- 1973-03-08 AR AR246951A patent/AR201101A1/es active
- 1973-03-08 IT IT48684/73A patent/IT979771B/it active
- 1973-03-08 AT AT205173A patent/AT320679B/de active
- 1973-03-08 LU LU67180A patent/LU67180A1/xx unknown
- 1973-03-08 SE SE7303248A patent/SE381892B/xx unknown
- 1973-03-08 DE DE2311556A patent/DE2311556C3/de not_active Expired
- 1973-03-08 FR FR7308278A patent/FR2175173B1/fr not_active Expired
- 1973-03-08 IL IL41733A patent/IL41733A/en unknown
- 1973-03-08 BE BE128507A patent/BE796440A/xx not_active IP Right Cessation
- 1973-03-08 NL NL7303297.A patent/NL162435C/xx not_active IP Right Cessation
- 1973-03-08 GB GB1129273A patent/GB1369576A/en not_active Expired
- 1973-03-09 JP JP48027238A patent/JPS5210678B2/ja not_active Expired
Cited By (61)
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 |
US4683040A (en) * | 1974-03-07 | 1987-07-28 | Asahi Kasei Kogyo Kabushiki Kaisha | Process for electrolysis of sodium chloride |
DE2510071B2 (de) | 1974-03-07 | 1980-11-27 | Asahi Kasei Kogyo K.K., Osaka (Japan) | Verfahren zur Elektrolyse von Natriumchlorid |
JPS50120492A (de) * | 1974-03-07 | 1975-09-20 | ||
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 |
US4683041A (en) * | 1974-03-07 | 1987-07-28 | Asahi Kasei Kogyo Kabushiki Kaisha | Process for electrolysis of sodium chloride |
JPS551351B2 (de) * | 1974-03-07 | 1980-01-12 | ||
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 |
JPS5514148B2 (de) * | 1977-07-15 | 1980-04-14 | ||
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 |
EP0136806A2 (de) * | 1983-09-06 | 1985-04-10 | Olin Corporation | Kontrollsystem für Chloralkali-Zelle auf Basis von Materialflussanalyse |
US4532018A (en) * | 1983-09-06 | 1985-07-30 | Olin Corporation | Chlor-alkali cell control system based on mass flow analysis |
EP0136806A3 (de) * | 1983-09-06 | 1987-08-26 | Olin Corporation | Kontrollsystem für Chloralkali-Zelle auf Basis von Materialflussanalyse |
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 |
US20110147229A1 (en) * | 2007-12-06 | 2011-06-23 | 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 |
US20090215977A1 (en) * | 2008-02-27 | 2009-08-27 | Bayer Materialscience Ag | Process for the preparation of polycarbonate |
US7858727B2 (en) | 2008-02-27 | 2010-12-28 | 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 |
DE102008011473A1 (de) | 2008-02-27 | 2009-09-03 | 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 |
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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 |
---|---|
BE796440A (fr) | 1973-09-10 |
IL41733A (en) | 1976-02-29 |
AR201101A1 (es) | 1975-02-14 |
JPS5210678B2 (de) | 1977-03-25 |
CA1003781A (en) | 1977-01-18 |
IL41733A0 (en) | 1973-06-29 |
FR2175173A1 (de) | 1973-10-19 |
AT320679B (de) | 1975-02-25 |
DE2311556B2 (de) | 1977-08-18 |
ES412416A1 (es) | 1976-05-01 |
NL162435B (nl) | 1979-12-17 |
DE2311556C3 (de) | 1982-05-19 |
DE2311556A1 (de) | 1973-09-13 |
SE381892B (sv) | 1975-12-22 |
GB1369576A (en) | 1974-10-09 |
LU67180A1 (de) | 1974-03-14 |
JPS491497A (de) | 1974-01-08 |
IT979771B (it) | 1974-09-30 |
NL162435C (nl) | 1980-05-16 |
NL7303297A (de) | 1973-09-11 |
FR2175173B1 (de) | 1976-11-05 |
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