摘要:
The present invention relates to process to prepare a chlorine-containing compound using an aqueous salt solution containing at least 100 g/l of sodium chloride and a contaminating amount of polyvalent cations comprising the steps of (i) preparing an aqueous salt solution containing at least 100 g/l of sodium chloride and at least 0.01 ppm of polyvalent cations by dissolving a sodium chloride source in water, (ii) adding an effective amount of at least one positive retention enhancing component to the aqueous solution, (iii) subsequently subjecting the solution to a nanofiltration step, thereby separating the solution into a retentate which is enriched for polyvalent cations and a permeate which is the purified aqueous salt solution, (iv) reacting the chloride anions in the permeate to a chlorine-containing compound by an electrolysis step, and (v) recycling at least part of the retentate to dissolution step (i).
摘要:
The present invention relates to a process to limit the content of impurities in the production of alkali metal chlorate, by integrating the production of chlorate with the production of chlorine and alkali metal hydroxide, which auxiliary chemicals are used in the chlorate process. The alkali metal chlorate is produced by electrolysis of a purified electrolyte containing alkali metal chloride, alkalization of the chlorate electrolyte obtained and precipitation of the chlorate formed by evaporation of the chlorate electrolyte. The very pure water separated in the crystallizer and alkali metal chloride is used in a membrane or diaphragm cell in the production of alkali metal hydroxide, which hydroxide is used in the production of alkali metal chlorate. Either pure chlorine or hydrogen chloride absorbed in water can be used in acidification, at which hydrogen chloride is produced from chlorine and hydrogen generated in the process.
摘要:
Disclosed is an improved process for electrolytically producing alkaline chlorate, carried out at an increased temperature by using an apparatus of a column type. The apparatus has a lower electrolysis zone, an intermediate reaction zone and an upper hydrogen-separation zone. The reaction zone has a central hollow section and a circumferential hollow section surrounding the central section. A solution to be electrolyzed is forced to circulate through the three zones by hydrogen gas generated so that the solution is allowed to flow down through the circumferential hollow section in a piston-flow manner after the hydrogen gas is separated from the solution. While the solution is passing through the circumferential section, effective auto-oxidation of hypochlorous acid is attained thereby causing the current efficiency of the electrolysis to be improved.
摘要:
A continuous closed-loop process for directly producing potassium chlorate by electrolysis of an aqueous potassium chloride solution with a metal anode is described. The process provides surprising advantages in efficiency by comparison with conventional double decomposition processed for producing potassium chlorate from electrolyzed sodium chloride.
摘要:
An electrode (10) is disclosed. The electrode (10) comprises an electrode substrate (20). A layer of TiOx (30, 40) with a total thickness in the range of between 40-200 μm is present on at least one surface of the electrode substrate (20) and a porosity of layer of TiOx (30, 40) is below 15%. An electro-catalytic layer (50) comprising oxides of ruthenium and cerium according comprising at least 50 molar % ruthenium oxides is present on layer of TiOx (30, 40) and wherein x is in the range 1-2 for the layer of TiOx. A process for the manufacture of the electrode (10) is disclosed as are uses thereof.
摘要:
The present invention relates to a process for production of alkali metal chlorate, and to a method of activating a cathode comprising electrolyzing an electrolyte comprising alkali metal chloride in an electrolytic cell in which at least one anode and at least one cathode are arranged wherein a) said electrolyte comprises chromium in any form in an amount ranging from about 0.01-10−6 to about 500-10−6 mol/dm3 b) said electrolyte comprises molybdenum, tungsten, vanadium, manganese and/or mixtures thereof in any form in a total amount ranging from about 0.1-10−6 mol/dm3 to about 0.5-10−3 mol/dm3.
摘要:
An undivided electrolysis cell for electrolyzing a liquor is disclosed which has a narrow gap between the electrodes and improved energy efficiency. The electrolysis cell comprises a porous anode, a porous cathode, and an electrically insulating separator therebetween which are all permeable to the liquor. Electrolysis is performed while directing the liquor through the porous anode, the electrically insulating separator, and the porous cathode. Gas products generated during electrolysis are carried out with the liquor and do not remain between the electrodes thereby reducing “gas blinding”. The electrolysis cell is particularly suitable for chlorate electrolysis.
摘要:
A gas diffusion electrode for an electro-synthetic or electro-energy cell, for example a fuel cell, including one or more gas permeable layers, a first conductive layer provided on a first side of the gas diffusion electrode, and a second layer, which may be a second conductive layer, provided on a second side of the gas diffusion electrode. The one or more gas permeable layers are positioned between the first conductive layer and the second layer, which may be a second conductive layer, and the one or more gas permeable layers provide a gas channel. The one or more gas permeable layers are gas permeable and substantially impermeable to the liquid electrolyte. The porous conductive material is gas permeable and liquid electrolyte permeable. The gas diffusion electrode can be one of a plurality of alternating anode/cathode sets.