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Related to Electrolyzer: electrolysis



an apparatus in which electrolysis is carried out, consisting of one or many electrolytic cells. An electrolyzer is a vessel (or system of vessels) filled with an electrolyte, in which electrodes—a cathode and anode—have been placed; the cathode is connected to the negative pole of the direct-current source and the anode is connected to the positive pole.

Various types of electrolyzers are used in industry and the laboratory, for example, open and hermetically sealed electrolyzers, electrolyzers for batch and continuous operation, electrolyzers with fixed or removable electrodes, and electrolyzers with various systems for separating the electrolysis products. Depending on their intended use, electrolyzers are designed for operation at different temperatures, from below 0°C (for example, the electrochemical synthesis of unstable oxygen compounds) to high temperatures (for example, in the electrolysis of molten electrolytes in the production of aluminum, calcium, and other metals), and they are accordingly equipped with systems for heating or cooling the electrolyte or electrodes. Some electrolyzers have a diaphragm—a porous barrier or membrane that separates the cathodic space from the anodic space and that is permeable to ions but retards mechanical mixing and diffusion. Asbestos, polymeric materials, and ceramics are used to make these diaphragms. Electrolyzers with ion-exchange membranes are also used. A distinction is made between unipolar and bipolar electrolyzers on the basis of how the electrolyzers are connected to the electric circuit. Unipolar electrolyzers consist of one electrolytic cell with electrodes of one polarity, each of which may consist of several elements connected in parallel to the circuit. Bipolar electrolyzers consist of many cells, as many as 100–160, which are connected in series to the circuit, and each electrode, with the exception of the two terminal electrodes, functions as a cathode at one end and an anode at the other.

The anodes are made of graphite, carbon-graphite materials, platinum, the oxides of several metals, lead, or lead alloys. Heavy-duty titanium anodes are also used, with an active coating made of a mixture of ruthenium oxide and titanium oxide or of platinum and its alloys. The cathode in most electrolyzers is made of steel. Liquid-electrode electrolyzers are also used (for example, mercury is used as the cathode in one method for the production of chlorine and sodium hydroxide). Some electrolyzers operate under pressure, for example, water is dissociated at pressures up to 4 meganewtons/m2 (40 kilograms-force/cm2). The development of electrolyzers operating at higher pressures is presently under way. When selecting the materials for the construction of electrolyzers, the corrosiveness of the electrolyte and electrolysis products, temperature, and other factors are taken into account. Steel, including steel with various protective coatings, plastics, glass, fiberglass, and ceramics are used. Large modern electrolyzers operate under large loads: unipolar electrolyzers, up to 400–500 kiloamperes, and bipolar electrolyzers, up to 1,600 kiloamperes.


References in periodicals archive ?
Fuel cell / Electrolyzer / Ultracapacitor Hybrid Power system: F Focus on Integration, PowerControl and Grid Synchronization" power system IEEE, 37: 10.
Right now, the prototype electrolyzer system is being thoroughly tested by welding professionals in the UK.
uses electrolysis to manufacture on-site, high-purity gas generators called proton exchange membrane (PEMs) electrolyzers.
The electrical characteristic (U-I) of an electrolyzer cell can be expressed as [22], [23]:
Mounted on skid, Osec B-Pak tubular cell electrolyzer systems generate 0.
The electrolyzer is anticipated to be delivered this year and will be capable of producing up to 130 kilograms per day of green hydrogen fuel from wind power to be used in electric fuel cell vehicles.
The technology includes an electrolyzer, a hydrogen storage and compression system, and multiple fueling dispensers, and is able to provide hydrogen, a hydrogen and compressed natural gas (HCNG) blend, and compressed natural gas for alternative fueled vehicles.
The refueling system produces hydrogen from water with an electrolyzer able to use electricity from any variety of sources, including off-peak or renewable energy generated by wind, wave or solar sources.
A PEM-based water electrolyzer works in much the same way as the archetypal junior high school chemistry experiment--the one with two wires attached to a lantern battery that are stuck into a beaker of dilute salt water--except that it uses a solid acid or membrane rather than a liquid solution.
The order covers a 250MW electrolyzer system and is valued at EUR350,000.
The power is run at low voltage through an electrolyzer, which uses electric current to break water molecules apart into hydrogen and oxygen.