EP1381715A1 - Verfahren zur gleichzeitigen elektrochemischen herstellung von natriumdithionit und natriumperoxodisulfat - Google Patents
Verfahren zur gleichzeitigen elektrochemischen herstellung von natriumdithionit und natriumperoxodisulfatInfo
- Publication number
- EP1381715A1 EP1381715A1 EP01933903A EP01933903A EP1381715A1 EP 1381715 A1 EP1381715 A1 EP 1381715A1 EP 01933903 A EP01933903 A EP 01933903A EP 01933903 A EP01933903 A EP 01933903A EP 1381715 A1 EP1381715 A1 EP 1381715A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- sodium
- dithionite
- catholyte
- anolyte
- platinum
- 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.)
- Withdrawn
Links
Classifications
-
- 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
- C25B1/28—Per-compounds
- C25B1/29—Persulfates
-
- 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
- C25B1/14—Alkali metal compounds
-
- 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
- C25B1/28—Per-compounds
Definitions
- sodium peroxodisulfate can be produced in addition to sodium hydroxide from sodium sulfate in a two-chamber cell with cation exchange membranes as separators (EP 0846 1 94).
- sodium dithionite which is used as a bleaching agent in the textile and paper industry and as a dyeing and printing aid, is preferably produced by chemical processes (W. Brückner, R. Sch Kunststoffs, G. Winter, K.-H. Büschel : Industrial inorganic chemistry, Weinheim: Verlag Chemie 1986).
- Dithionites are obtained in technology by reducing sulfur dioxide Zinc, with sodium formate in a pressure reaction or with sodium tetrahydroborate. The cathodic reduction of sulfur dioxide also leads to dithionite.
- sodium amalgam is used as a reducing agent (Ullmanns Encyclopedia Industrial Chemistry, Vol. A 25, pp. 483-484, Weinheim 1 994).
- this process is no longer up to date.
- the invention is based on the problem of simultaneously producing sodium dithionite and peroxodisulfate with good economy by electrochemical means.
- anodic sodium peroxodisulfate and cathodic sodium dithionite are coated in one or more electrolytic cells divided by cation exchange membranes with anodes made of smooth platinum or valve metals coated with platinum or diamond or niobium, tantalum, titanium or zirconium as well as cathodes made of carbon, stainless steel, silver or coated with platinum metals Materials manufactured with current densities of 1.5 to 6 kA / m 2 and temperatures of 20 to 60 ° C. Sodium sulfate and water are added to the anolyte circulating through the anode compartments.
- the anodically released sodium ions reach the cathode compartment through the cation exchange membranes.
- a pH in the range from 4 to 6 is set by adding sulfur dioxide, water and, if appropriate, sodium bisulfite to the catholytes circulating over the cathode spaces.
- Sulfur dioxide, or sulfuric acid and bisulfite solution are the important ones Basic chemicals to produce sodium peroxodisulfate and sodium dithionite in crystalline form.
- the electrolysis current is used twice, which significantly reduces both the specific system costs - based on the sum of the products obtained - and the running operating costs, and here in particular the specific electrical energy consumption.
- the required total concentration of sodium ions can be adjusted by additional metering of sodium sulfite or sodium bisulfite or sodium hydroxide solution into the catholyte circuit.
- the electrolysis can also be operated at temperatures of up to 50 ° C. without the dithion ions formed decaying appreciably and thus reducing the current efficiency.
- Average residence times of the sodium dithionite formed in the catholyte circuit of less than 30 minutes should preferably be aimed for. This is possible by minimizing the amount of catholyte circulating in the entire catholyte circuit.
- the relative speed of the catholyte along the cathode should be at least 0.1 m / s, preferably 0.3 to 0.5 m / s. Since similar flow velocities and residence times are also favorable for the anodic formation of peroxodisulfate, there is the advantage of an approximately symmetrical structure of the two Electrolyte circulation systems, combined with an approximately equal pressure build-up in both electrode spaces with only slight pressure differences between the cation exchange membrane.
- both starting materials can be generated in situ in a chemical reactor by reacting sodium bisulfite or sodium sulfite with sulfuric acid in situ:
- the industrially available bisulfite liquor can also be used for this. It is advantageous to keep the residual sulfur dioxide content in the sodium sulfate solution formed as low as possible by stripping with steam in order to be able to feed it directly into the anolyte.
- This procedure has u. a. the advantage that the current density in the cathode compartment and in the cation exchange membrane is lower than at the anode and in the adjacent anode compartment, whereby the voltage drop and thus the specific electrical energy consumption is significantly reduced despite the required high anodic current densities.
- the catholyte can also be used to stabilize the dithionite or to maintain the desired pH, such as. B. phosphoric acid and / or phosphates can be added.
- the aqueous solutions of sodium dithionite and sodium peroxodisulfate obtained which also contain sulfite or sodium sulfate and sulfuric acid, can be worked up to give the crystalline solid end products, it being possible for the mother liquors to be returned from the crystallization processes to the electrolyte circuits.
- FIG. 1 shows the flow diagram of an exemplary electrolysis plant with a prereactor for the in-situ production of sulfur dioxide and sodium sulfate from bisulfite lye.
- the pre-reactor 1 2 sulfuric acid and 3 bisulfite liquor are metered in in such a ratio that on the one hand the amount of sulfur dioxide consumed in the process is formed and on the other hand the sodium present is almost completely converted into sodium sulfate.
- the approximately concentrated sodium sulfate solution obtained at the bottom of the reactor is fed into the anolyte circuit at 4 and the sulfur dioxide emerging at the top of the reactor is fed into the catholyte circuit at 5.
- the catholyte is circulated by means of a circulation pump 6 through the cathode spaces 7 of the electrolytic cell 8 and the gas separator 9.
- the amount of water required to achieve the desired final concentration is metered into the catholyte circuit.
- the separated anode gas emerges, and at 1 2, an amount of catholyte corresponding to the amount of liquid supplied, enriched with sodium dithionite, overflows.
- the cathode compartment is separated from the anode compartment 14 by the cation exchange membrane 1 3.
- the Anolyte is pumped around by means of the circulation pump 1 5 via the anode compartments and the gas separator 1 6 and the dissolving vessel 1 7.
- Crystalline sodium sulfate is added to the anolyte at 1 8 in the dissolving vessel.
- the potential-increasing electrolysis additive is metered in, and at 20 the separated anode gas emerges.
- the sodium peroxodisulfate solution formed emerges from the overflow of the dissolving vessel 21.
- Example 2 In a small-scale test facility modified from Example 1 without a prereactor, the anolyte and catholyte were circulated by means of circulation pumps through the electrode spaces of the electrolysis cell and the gas separators.
- the dissolving vessel for sodium sulfate shown in FIG. 1 was also integrated into the anolyte circuit.
- Deionized water with an addition of sodium thiocyanate (as a potential-increasing additive) was metered into the anolyte circuit using a metering pump. Solid anhydrous sodium sulfate was also metered into the dissolving vessel.
- Gaseous sulfur dioxide was fed into the catholyte circuit from a gas bottle and a sodium sulfite solution was fed in by means of a metering pump.
- the sodium sulfite was used to compensate for a deficit of sodium compounds occurring there as a result of the lower transfer of sodium ions from the anode space to the cathode space.
- the pH was adjusted to about 5.8. This allowed the amount of SO 2 fed in to be optimally adapted to the transfer of the sodium ions.
- a bipolar filter press electrolysis cell as used for the production of peroxodisulfate and described in DE 44 1 96 83 served as the electrolysis cell. It consisted of three electrode plates housed in a clamping frame, two of which were edge plates with power supply and a middle bipolar electrode plate. Thus, two electrolytic cells were formed, the electrical series switched and were connected in parallel with regard to the electrolyte currents.
- the electrode plates consisted of impregnated graphite with integrated cooling channels and incorporated inlets and outlets for the electrolyte solutions and the cooling water. Insulating plates made of PVC and approx. 3 mm thick sealing frames made of EPDM were applied on the anode side.
- Transversely arranged platinum foil strips were arranged as anodes on the insulating plate, which were contacted laterally below the sealing frame with the graphite base bodies. Both electrode spaces were separated by National 450 (DuPont) cation exchange membranes.
- the cathode compartments were incorporated into the base body in the form of parallel-flow channels (4 mm deep). Since the cell was 2,000 mm high, the cross-sections of the anode compartments and cathode compartments with flow could be kept very low at approx. 1.5 cm 2 , as a result of which high flow velocities along both electrodes could be achieved.
- the liquid volume in the cathode circuit was minimized in order to be able to achieve the shortest possible residence times.
- volume of anolyte circuit with dissolving vessel 6.5 I.
- Circulation quantity anolyte catholyte: 400 l / h
- the cooling of the cathode was adjusted so that the temperature in the circulating catholyte was approximately 35 ° C. and a temperature of approximately 48 ° C. was established in the anolyte.
- the cell voltage was 5.5 V (total voltage 1 1 V).
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)
Abstract
Description
Claims
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19954299A DE19954299A1 (de) | 1999-11-11 | 1999-11-11 | Verfahren zur gleichzeitigen elektrochemischen Herstellung von Natriumdithionit und Natriumperoxodisulfat |
PCT/EP2001/004790 WO2002088429A1 (de) | 1999-11-11 | 2001-04-27 | Verfahren zur gleichzeitigen elektrochemischen herstellung von natriumdithionit und natriumperoxodisulfat |
CA002345451A CA2345451A1 (en) | 1999-11-11 | 2001-04-27 | Process for the simultaneous electrochemical preparation of sodium dithionite and sodium peroxodisulfate |
US09/845,021 US6454929B1 (en) | 1999-11-11 | 2001-04-27 | Process for the simultaneous electrochemical preparation of sodium dithionite and sodium peroxodisulfate |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1381715A1 true EP1381715A1 (de) | 2004-01-21 |
Family
ID=27427698
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP01933903A Withdrawn EP1381715A1 (de) | 1999-11-11 | 2001-04-27 | Verfahren zur gleichzeitigen elektrochemischen herstellung von natriumdithionit und natriumperoxodisulfat |
Country Status (5)
Country | Link |
---|---|
US (1) | US6454929B1 (de) |
EP (1) | EP1381715A1 (de) |
CA (1) | CA2345451A1 (de) |
DE (1) | DE19954299A1 (de) |
WO (1) | WO2002088429A1 (de) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19954299A1 (de) * | 1999-11-11 | 2001-05-17 | Eilenburger Elektrolyse & Umwelttechnik Gmbh | Verfahren zur gleichzeitigen elektrochemischen Herstellung von Natriumdithionit und Natriumperoxodisulfat |
JP4515804B2 (ja) * | 2004-04-08 | 2010-08-04 | 新興化学工業株式会社 | 電解採取による金属インジウムの回収方法 |
DE102004053090A1 (de) * | 2004-11-03 | 2006-05-04 | Basf Ag | Verfahren zur Herstellung von Natriumdithionit |
TWI439571B (zh) | 2007-01-15 | 2014-06-01 | Shibaura Mechatronics Corp | Sulfuric acid electrolysis device, electrolysis method and substrate processing device |
TW200923238A (en) * | 2007-11-26 | 2009-06-01 | Toford Plastic Mfg Corp | Pipe structure |
DE102015003911A1 (de) * | 2015-03-27 | 2016-09-29 | Eilenburger Elektrolyse- Und Umwelttechnik Gmbh | Verfahren zur Desinfektion von Schwimmbecken-, Trink- und Gebrauchswasser sowie zur Herstellung eines Desinfektionsmittelkonzentrats |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3920551A (en) * | 1973-11-01 | 1975-11-18 | Hooker Chemicals Plastics Corp | Electrolytic method for the manufacture of dithionites |
US3905879A (en) * | 1973-11-01 | 1975-09-16 | Hooker Chemicals Plastics Corp | Electrolytic manufacture of dithionites |
DE2646825A1 (de) * | 1976-10-16 | 1978-04-20 | Basf Ag | Verfahren zur kontinuierlichen herstellung von natriumdithionitloesungen durch kathodische reduktion |
DE4326540A1 (de) * | 1993-08-07 | 1995-02-09 | Basf Ag | Verfahren zur Herstellung von Peroxodischwefelsäure und Peroxomonoschwefelsäure |
TW364024B (en) | 1995-08-17 | 1999-07-11 | Eilenburger Elektrolyse & Umwelttechnik Gmbh | Process for the combined electrochemical preparation of sodium peroxodisulfate and sodium hydroxide solution |
TW416997B (en) * | 1998-03-30 | 2001-01-01 | Mitsubishi Gas Chemical Co | Process for producing persulfate |
DE19954299A1 (de) | 1999-11-11 | 2001-05-17 | Eilenburger Elektrolyse & Umwelttechnik Gmbh | Verfahren zur gleichzeitigen elektrochemischen Herstellung von Natriumdithionit und Natriumperoxodisulfat |
-
1999
- 1999-11-11 DE DE19954299A patent/DE19954299A1/de not_active Withdrawn
-
2001
- 2001-04-27 EP EP01933903A patent/EP1381715A1/de not_active Withdrawn
- 2001-04-27 WO PCT/EP2001/004790 patent/WO2002088429A1/de active Application Filing
- 2001-04-27 CA CA002345451A patent/CA2345451A1/en not_active Abandoned
- 2001-04-27 US US09/845,021 patent/US6454929B1/en not_active Expired - Fee Related
Non-Patent Citations (1)
Title |
---|
See references of WO02088429A1 * |
Also Published As
Publication number | Publication date |
---|---|
CA2345451A1 (en) | 2002-10-27 |
US6454929B1 (en) | 2002-09-24 |
DE19954299A1 (de) | 2001-05-17 |
WO2002088429A1 (de) | 2002-11-07 |
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