Abstract: Demand-based closed-loop control is used in an electrochemical plant that has modules and a control unit, with each module being individually controlled by the control unit and supplied with a module-specific electric operating current. For each module to generate a separate product flow, product flows of the individual modules, connected in parallel, are merged to form a total product flow. When a start condition occurs, the control unit records a current total product flow demand, records a current efficiency of the modules based on a ratio of respective operating current and product flow, determines operationally ready modules, determines module-specific target operating currents for the operationally ready modules to cover the demand from a range of permissible module-specific target operating currents based on the efficiency of the modules and the demand, and sets the operating currents of the operationally ready modules to the determined module-specific target operating currents.

Abstract: An electrolysis device for the electrolytic treatment of liquids has an anode chamber and a cathode chamber which are separated from one another via an ion exchange membrane. The chambers are provided with an inlet opening and an outlet opening for the flowing electrolyte, each with one electrode. The inner space of the anode chamber and/or of the cathode chamber are/is subdivided by webs or ribs extending transversely with respect to the electrodes. The webs or ribs are provided at least regionally with holes or cut outs. The webs or ribs include at least one lower region free of holes or cut outs. The electrolysis device provides sufficient mixing in the upper foam phase in the longitudinal direction and also at the same time the airlift pump effect is maintained by way of ascending gas bubbles in the lower region.

Abstract: An electrolytic cell may include a cathode half-cell having a cathode, an anode half-cell having an anode, and a separator that separates the two half-cells from one another and that is permeable to electrolyte present in the half-cells during operation. At least one inlet for electrolyte is provided in a first half-cell of the two half-cells, and at least one outlet for electrolyte and no inlet for electrolyte are provided in the second half-cell such that electrolyte supplied via the at least one inlet is dischargeable via the at least one outlet after passing through the separator. A method can also be utilized to operate such an electrolytic cell. And an electrolyzer may include multiple of such electrolytic cells.

Abstract: An electrolysis device for the electrolytic treatment of liquids has an anode chamber and a cathode chamber which are separated from one another via an ion exchange membrane. The chambers are provided with an inlet opening and an outlet opening for the flowing electrolyte, each with one electrode. The inner space of the anode chamber and/or of the cathode chamber are/is subdivided by webs or ribs extending transversely with respect to the electrodes. The webs or ribs are provided at least regionally with holes or cut outs. The webs or ribs include at least one lower region free of holes or cut outs. The electrolysis device provides sufficient mixing in the upper foam phase in the longitudinal direction and also at the same time the airlift pump effect is maintained by way of ascending gas bubbles in the lower region.

Abstract: Methods for providing at least one product stream, in particular hydrogen, by electrolysis by means of an electrolyzer having a multiplicity of electrolysis cells combined to form at least one framework; wherein electrolyte is discharged from the cells and separated into two phases. The electrolyte is collected upstream of a pump system. At least the functions of discharge and collection are carried out integrally together in a multifunctional collection container or in an integral method step, in particular by means of at least one multifunctional collection container with a regulatable filling level coupled to the cells. This extends the functionality and also provides an advantageous design construction. The invention furthermore relates to a corresponding electrolysis device and to a corresponding multifunctional collection container.

Abstract: Processes for alkaline electrolysis of water may involve pumping an electrolyte in a circuit between an anode half-cell and a cathode half-cell so as to keep the electrolyte concentration constant throughout the electrolysis process. One such process may involve supplying electrolyte from a first liquid reservoir to the anode half-cell and supplying an anolyte flowing out of the anode half-cell to an anodic gas separator, where gas is separated from the anolyte. The electrolyte may be supplied from a second liquid reservoir to the cathode half-cell and a catholyte flowing out of the cathode half-cell may be supplied to a cathodic gas separator, where gas is separated from the catholyte. Gas-stripped anolyte from the anodic gas separator may be returned to the second liquid reservoir and gas-stripped catholyte from the cathodic gas separator may be returned to the first liquid reservoir.

Abstract: Methods for providing at least one product stream, in particular hydrogen, by electrolysis by means of an electrolyzer having a multiplicity of electrolysis cells combined to form at least one framework; wherein electrolyte is discharged from the cells and separated into two phases. The electrolyte is collected upstream of a pump system. At least the functions of discharge and collection are carried out integrally together in a multifunctional collection container or in an integral method step, in particular by means of at least one multifunctional collection container with a regulatable filling level coupled to the cells. This extends the functionality and also provides an advantageous design construction. The invention furthermore relates to a corresponding electrolysis device and to a corresponding multifunctional collection container.

Abstract: An electrolysis device for the electrolytic treatment of liquids has an anode chamber and a cathode chamber which are separated from one another via an ion exchange membrane. The chambers are provided with an inlet opening and an outlet opening for the flowing electrolyte, each with one electrode. The inner space of the anode chamber and/or of the cathode chamber are/is subdivided by webs or ribs extending transversely with respect to the electrodes. The webs or ribs are provided at least regionally with holes or cut outs. The webs or ribs include at least one lower region free of holes or cut outs. The electrolysis device provides sufficient mixing in the upper foam phase in the longitudinal direction and also at the same time the airlift pump effect is maintained by way of ascending gas bubbles in the lower region.

Abstract: A method for determining a charge state of a vanadium redox flow cell may comprise indirectly determining concentrations of V4+ and V5+ in a positive electrolyte by mixing positive and negative electrolytes with one another in particular proportions to reduce V5+ present in the positive electrolyte. In this way, CT complexes of V4+/V5+ may be avoided, the concentration of which is not determinable directly owing to the strong UV/vis absorption. Furthermore, the method enables determination of the concentrations of the negative electrolyte and positive electrolyte via UV/vis absorptions, which enables simple monitoring of the charge state of a vanadium redox flow battery.

Abstract: Flow type electrochemical cells are disclosed. The electrochemical cell has an anode half-cell, a cathode half-cell, and permeable separating layer. The half-cells are bounded by side elements. Respective porous electrodes are housed in the half-cells. The permeable separating layer is disposed between the anode half-cell and the cathode half-cell. An electrolyte region connected to an electrolyte feed and an electrolyte outflow region connected to an electrolyte drain are further provided. An electrolyte inflow region and an electrolyte outflow region are disposed on opposite sides of the porous electrodes such that inflowing electrolyte flows through the porous electrode perpendicularly to the permeable separating layer.

Abstract: Flow type electrochemical cells are disclosed. The electrochemical cell has an anode half-cell, a cathode half-cell, and permeable separating layer. The half-cells are bounded by side elements. Respective porous electrodes are housed in the half-cells. The permeable separating layer is disposed between the anode half-cell and the cathode half-cell. An electrolyte region connected to an electrolyte feed and an electrolyte outflow region connected to an electrolyte drain are further provided. An electrolyte inflow region and an electrolyte outflow region are disposed on opposite side of the porous electrodes such that inflowing electrolyte flows through the porous electrode perpendicularly to the permeable separating layer.