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
  • C25B1/24—Halogens or compounds thereof
  • C25B1/26—Chlorine; Compounds thereof

Definitions

• the present invention relates to a process for preparing chlorine by electrolysis of aqueous hydrochloric acid in which compounds of metals occuring in several oxidation stages that are easy to convert into one another are added to the electrolyte to cut down the cell voltage.
• the present invention provides a process for the preparation of chlorine by electrolysis of aqueous hydrochloric acid in the presence of metal compounds occuring in several oxidation stages that are easy to convert into one another, wherein with considerable gain in voltage the current efliciency is over and no additional and complicated process steps or installations are required.
• the electrolysis of aqueous hydrochloric acid is carried out in cells with vertical electrode arrangement, the anode and cathode spaces of which are separated by diaphragms.
• anolyte and as catholyte solutions are used that are 4 to 8 times molar with respect to the hydrochloric acid and contain 0.5 to 2 mols of copper chloride or iron chloride per liter of solution.
• hydrogen chloride is introduced into the anolyte in the same measure as it is consumed and an oxidizing gas is introduced into the catholyte and the differential pressure between the anode space and the cathode space is maintained at zero.
• the limiting current density is determined by the speed of the re-oxidation of the metal compound reduced at the cathode. As soon as the cathodic reduction is more rapid than the reoxidation due to too high a current density, the cell voltage gradually rises to the separation voltage of hydrogen.
• nonionic, nonfoaming wetting agents Especially suitable are butyl diglycol (butyl ether of diethylene glycol) and particularly dibutyl diglycol (dibutyl ether of diethylene glycol).
• the wetting agent is added to the electrolyte in an amount of up to about 1 gram per liter.
• Air can be used as oxidizing gas.
• the re-oxidation can be considerably accelerated when oxygen is used as oxidizing gas.
• oxygen used as oxidizing gas
• an addition of about 1 g./l. of dibutyl diglycol to the electrolyte an addition of about 1 g./l. of dibutyl diglycol to the electrolyte, current densities are obtained as reached in a conventional mode of operation while simultaneously current efiiciencies of over 90% are possible with about one-half of the hitherto required cell voltage.
• the oxidizing gas is introduced into the catholyte in an amount such that at least about 40% of the metal ions present are in the higher valence stage and that the water formed in the oxidation is blown out of the cell with the gas current.
• the elec- 20 EXAMPLE 2 trode spaces can be closed for the liquid and only provided with installations for the supply of hydrogen chloride and oxygen or air and for the removal of chlorine, air or oxygen and steam.
• Table 2 indicates the results of a test carried out under the conditions of test 2 of Example 1 but without the use of a wetting agent.
• the lectrolyte EXAMPLE 3 can be circulated by means of a pump in the cathode space or in the anode space or in both electrode spaces or it can be cycled through external coolers.
• Table 5 shows the results of a test in which iron chloride 7 was used intsead of a copper salt.

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)
• Road Paving Machines (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=7102026

Family Applications (1)

Country Status (10)

Cited By (3)

Citations (6)

Family Cites Families (2)

• 1966
  • 1966-01-03 DE DEF48078A patent/DE1277216B/de active Pending
  • 1966-12-20 US US603143A patent/US3486994A/en not_active Expired - Lifetime
  • 1966-12-28 NL NL6618274A patent/NL6618274A/xx unknown
  • 1966-12-29 ES ES335071A patent/ES335071A1/es not_active Expired
• 1967
  • 1967-01-02 NO NO166229A patent/NO116757B/no unknown
  • 1967-01-02 GB GB81/67A patent/GB1140481A/en not_active Expired
  • 1967-01-03 FI FI0012/67A patent/FI45852B/fi active
  • 1967-01-03 SE SE77/67A patent/SE324353B/xx unknown
  • 1967-01-03 BE BE692089D patent/BE692089A/xx unknown
  • 1967-01-03 FR FR89784A patent/FR1507413A/fr not_active Expired

Patent Citations (6)

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