Basic operation principles and control algorithm for a high-pressure membrane-less electrolyser

• Main Authors: Solovei, V. V., Kotenko, A. L., Vorobiova, I. O., Shevchenko, A. A., Zipunnikov, M. M.
• Format: Article
• Language: English; Ukrainian
• Published: Інститут енергетичних машин і систем ім. А. М. Підгорного Національної академії наук України 2019
• Subjects: electrolyzer; gas absorption electrode; hydrogen; oxygen; UDC 544.6.018.42; электролизер; газопоглощающий электрод; водород; кислород; УДК 544.6.018.42; електролізер; газопоглинаючий електрод; водень; кисень
• Online Access: https://journals.uran.ua/jme/article/view/154466

A technology of the cyclic generation of hydrogen and high-pressure oxygen, implemented in a single-module and multi-module electrolysis installation, is considered. A schematic operation diagram for implementing the method with four series-connected modules is given. During the cyclic supply of alternating potentials to the active and passive electrodes to obtain each of the gases separately in time while the other gas is being simultaneously and reversibly absorbed by the active electrode, the process can be carried out with both single-module and multi-module circuits  series-connected to an electrical circuit and either separate modules or electrolyzer blocks removed (by shunting) from the electrical circuit without interrupting the process of producing gases with the optimal regulation of gas productivity under the conditions of the technological process. This makes it possible to realize the operation of an electrolysis installation with low current loads, reducing the risk of electrical breakdowns inside electrolyser modules. A four-module electrolysis installation control algorithm is described. The optimal parameters for regulating the performance of gases are determined according to the requirements of the technological process. An analysis of the cyclogram of hydrogen and oxygen generation with the limitation of the reaction voltage from 0.5 to 1.8 V has been carried out. The range of operating temperatures of the developed electrolysis process is in the range from 280 to 423 K, and the pressure range is 0.1 to 70 MPa. The dependence of the volt-ampere characteristics of a high-pressure electrolyzer power supply system on the number of series-connected modules of a given performance is given. The optimal regulation of gas performance on demand of the technological process or in cases of removing individual modules from the electrical circuit without interrupting the process of generating gases has been carried out by controlling the amount of current in the electrical system according to inversely proportional dependence from the number of connected modules. The appearance of an electrode assembly design using a gas absorption electrode is considered. Recommendations for implementing an electrolysis installation operation with low current loads and reducing the risk of electrical breakdowns inside electrolyzer modules are indicated.