A side stream subsystem can be used to remove impurity species from the recirculating alkali metal chloride solution in certain electrolysis systems. Silicon and/or aluminum species can be removed via precipitation after introducing an alkali metal hydroxide and magnesium chloride in a side stream line in the subsystem. The invention can allow for a substantial reduction in raw material and capital costs.

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.

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.sup.6 to about 500-10.sup.6 mol/dm.sup.3 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.sup.6 mol/dm.sup.3 to about 0.5-10.sup.3 mol/dm.sup.3.

A method of welding a ferritic stainless steel part to a carbon steel part is described. The method comprises arc welding (e.g. GTAW welding) the ferritic stainless steel part to the carbon steel part using a duplex stainless steel filler metal. Welded article made in this way is useful for industrial electrolyzers and particularly for corrosion resistant cathode and carrier plate assemblies in a sodium chlorate electrolyzer.

The present disclosure relates to a process for the production of alkali metal chlorate in a single compartment electrolytic cell, which avoids the need for addition of sodium dichromate to the process, in which unwanted side-reactions are reduced by using a cathode having an electrocatalytic top layer on a substrate that optionally also has one or more intermediate layers. The top electrocatalytic layer comprises an oxide of manganese and/or cerium.

The electrochemical reactors disclosed herein provide novel oxidation and reduction chemistries and employ increased mass transport rates of materials to and from the surfaces of electrodes therein.

The electrochemical reactors disclosed herein provide novel oxidation and reduction chemistries and employ increased mass transport rates of materials to and from the surfaces of electrodes therein.

A system, comprising: a chlorine source in form of an electrolysis unit to generate an insitu generated active chlorine; wherein a concentration of perchlorate is not more than half of a concentration of chlorate; and pH of a fluid containing in-situ generated active chlorine is more than 7.4; a buffer tank to store a concentrate of in-situ generated active chlorine as a free available chlorine (FAC); a fluid distribution system to supply FAC in form of an in-use fluid to the cabinet; wherein the system is configured to clean and disinfect an article with the fluid while complying with national and international standards for food safety, operator's safety and regulatory requirements regarding the use of biocides.

Disclosed is a combined electrical current carrier, circulation chamber and frame (CCF) formed as a single or double part (CCF) for use in unipolar electrochemical devices, such as a filter press electrolyser apparatus. The CCF is structured to define an internal circulation chamber for circulation of electrolyte, products, and reactants as well as apertures which form flow passageways when the filter press device is assembled. Affixed on opposed surfaces of the CCFs are electrically conductive planar electroactive structures which are in electrical contact with the CCF. The circulation chamber is formed by the depth of the CCF itself between opposing electroactive structures. Multiple CCFs are assembled and compressed together to form the filter press electrolyser apparatus. The flow passageway apertures within the assembled filter press electrolyser are aligned to form flow pathways, located above and below the circulation chambers. Reactants and electrolyte are input along the bottom flow pathways. When power is applied to the CCFs and electroactive structures, the reactants, once they flow into the circulation chamber with the electrolyte, undergo redox reactions to produce the products which are then collected and exit the electrolyser in the upper flow pathways.

A system, comprising: a chlorine source in form of an electrolysis unit to generate an insitu generated active chlorine; wherein a concentration of perchlorate is not more than half of a concentration of chlorate; and pH of a fluid containing in-situ generated active chlorine is more than 7.4; a buffer tank to store a concentrate of in-situ generated active chlorine as a free available chlorine (FAC); a fluid distribution system to supply FAC in form of an in-use fluid to the cabinet; wherein the system is configured to clean and disinfect an article with the fluid while complying with national and international standards for food safety, operator's safety and regulatory requirements regarding the use of biocides.