Electrolysis system and method of operation thereof

Abstract

Disclosed are electrolysis techniques and system implementations comprising a plurality of reactors, each comprising an electrolysis electrode and configured to perform a sequence of phases of an electrolysis process, the sequence of phases of the electrolysis process being phase-shifted relative to a sequence of phases of an electrolysis process performed by at least another one of the plurality of reactors; one or more power sources for driving the electrolysis process performed by the plurality of reactors; and a control system configured to monitor changes in the power capacity of at least one of the one or more power sources and, based thereon, at least one of: (i) activating or deactivating one or more of the electrolysis processes performed by the plurality of reactors; (ii) adjusting a duration of at least one of the phases of the electrolysis process; (iii) adjusting power supplied from the one or more power sources to at least one of the plurality of reactors; and / or (iv) adjusting, removing or introducing at least one phase of the electrolysis process.

Description

[Technical field]

[0001] The present invention is generally in the field of electrolysis, and specifically relates to control schemes for electrolytic cells. [Background technology]

[0002] This section is intended to provide background information related to the present application, which may not necessarily be prior art.

[0003] Electrolyzers usually receive their power supply from the electric grid infrastructure, and electrolyzers are generally designed to operate with a steady power supply to obtain optimal hydrogen production rates. A continuous and steady power supply is especially required in such systems, since a sudden drop in the electrolyzer's electric power supply can cause electrode deterioration and hydrogen production to stop. In electrolysis, since hydrogen and oxygen are produced simultaneously at the same time (hydrogen on the cathode and oxygen on the anode), a membrane is generally placed between the two electrodes to prevent mixing of the produced gases. However, some of the produced hydrogen and oxygen gases will still diffuse through the membrane and recombine with the other gas to form water, thereby reducing the efficiency of the production process.

[0004] At low power, this trickle of gas is more pronounced and there is a higher share of hydrogen (and oxygen) crossover. In this regard, it is noted that when renewable power sources are used to generate the electric power supply for the electrolysis equipment, reductions in the electric power supply are inevitable. Since renewable power sources are unstable in nature, alternations of the electric power supply are made periodically according to changes in the availability and / or strength of the renewable source.

[0005] If this gas drip is increased above the flammability limit, this can result in combustion. Furthermore, the power provided to the electrodes of the electrolyser can be reduced, but other components of the electrolyser system, such as pumps, cannot be operated efficiently at the lower power levels, resulting in an overall lower efficiency (Balance of Plant, BoP).

[0006] Using green energy sources for electrolysis systems is a challenging task since the power produced by most renewable energy sources is of an intermittent nature such that large fluctuations in available electrical power usually occur. In particular, wind and solar-based power sources, which are considered the largest renewable power sources, can change in intensity rapidly, e.g., due to weather conditions. Thus, connecting electrolyzer systems to such renewable power sources is difficult. For example, solar power plants utilize a series / parallel connection of multiple photovoltaic (PV) cells to convert solar energy into electrical energy. The operation of such solar power plants is strongly influenced by local climatic conditions (e.g., temperature, wind, and availability of solar radiation) and electrical parameters (e.g., PV cell temperature).

[0007] Electrochemically Thermally Activated Chemical cells (E-TAC) (disclosed, for example, in International Patent Publication Nos. WO2022 / 029776 and / or WO2022 / 029777, of the same applicant as the present application, the disclosures of which are incorporated herein by reference) are a new type of hydrogen production system that separates hydrogen and oxygen production into different "phases" and can achieve much higher efficiencies compared to conventional electrolysis systems. In E-TAC systems, hydrogen and oxygen are not produced at the same time, so there is no need for a membrane to separate the electrodes and there is no risk of hydrogen and oxygen mixing under low power consumption conditions.

[0008] This means that the E-TAC system is inherently capable of supporting low power consumption conditions, however, the operation of the E-TAC system must be carefully controlled in order for the E-TAC system to operate efficiently under such low power consumption conditions. Summary of the Invention [Problem to be solved by the invention]

[0009] In a broad aspect, the present application provides a plant management scheme for a plant having at least one power source and / or several simultaneously operating processes that are subject to changes and / or discontinuities at any time during its operation. For example, in some embodiments, at least one power source of the plant is a renewable power source (e.g., solar radiation) whose availability and / or power intensity may vary unpredictably during the operation of the plant. In some embodiments, the plant is configured to simultaneously perform several production (e.g., electrolysis) processes, which may be rapidly changed during its operation to add or reduce such production processes according to production requirements / conditions and / or the availability and / or power intensity of the at least one renewable power source.

[0010] In some embodiments, the power management of the plant is configured to monitor the power production level of the at least one renewable power source and, based thereon, determine how to utilize the power generated thereby and / or new operating states and / or conditions of the plant's process. For example, if the at least one renewable power source is capable of providing a high power production level, the power management system can draw therefrom sufficient power to operate the plant's production process and feed the remainder of the generated power to the electric grid system. When the power production level of the at least one renewable power source is reduced to a level less than the high power level and greater than a defined intermediate power production level, the power management system can direct all of the power generated thereby for operation of the plant's production process.

[0011] If the power production level of the at least one renewable power source is reduced to a level less than the defined medium power production level and greater than the defined low power production level, the power management system may direct all of the power generated thereby for operation of the plant's production process, consume some amount of electric grid power to operate the plant's production process, and / or change the state and / or condition of operation of the production process to adjust their power consumption to the new power capacity level of the at least one renewable power source.

[0012] If the power production level of the at least one renewable power source is further reduced, for example to a level less than a defined low power production level, the power management system may reduce the number of simultaneously operating production processes of the plant and / or draw more power from the electric grid. If the power production level of the at least one renewable power source is reduced to a critically minimum level, the power management system may consume more power from the electric grid or, alternatively, pause the production processes of the plant and resume at least some of those production processes when sufficient power is generated by the at least one renewable power source.

[0013] Additionally or alternatively, the power management system may be configured to adjust the operating states and conditions of the production processes of the plant in response to changes in the power production levels of the renewable power sources and their expected duration. For example, if minor short-term fluctuations in the power produced by the at least one renewable power source are observed, the power management system may adjust the operation of the simultaneously operated production processes to reduce the total power consumption of the plant, e.g., by changing the operation mode of the plant components to a lower power consumption. If longer-term changes in the power produced by the at least one renewable power source are observed, the power management system may change the operation sequence of the production processes to further adjust the power consumption of the plant, e.g., by reducing the duration of power-consuming phases and / or increasing the duration of substantially inactive phases, i.e., phases in the production process that require relatively small or no power consumption.

[0014] If longer term changes are observed in the power production levels of at least one renewable power source, the power management system may further adjust the operation of the plant's production processes to further reduce the plant's power consumption, for example, by reducing the number and / or duration of power consuming phases and / or increasing the number and / or duration of substantially inactive steps and / or deactivating one or more of the production processes. [Means for solving the problem]

[0015] In one aspect, an electrolysis system is provided comprising: a plurality of reactors, each comprising an electrolysis electrode and configured to perform a sequence of phases of an electrolysis process, the sequence of phases of the electrolysis process being phase-shifted (i.e., having a phase differential) relative to a sequence of phases of an electrolysis process performed by at least another one of the plurality of reactors; one or more power sources for driving the electrolysis process performed by the plurality of reactors; and a control system configured to monitor changes in the power capacity of at least one of the one or more power sources and, based thereon, at least one of: (i) activating or deactivating one or more of the electrolysis processes performed by the plurality of reactors; (ii) adjusting a duration of at least one of the phases of the electrolysis process; (iii) adjusting power supplied from the one or more power sources to at least one of the plurality of reactors; and / or (iv) adjusting, removing or introducing at least one phase of the electrolysis process.

[0016] The system may be configured to perform an electrolysis process in each reactor during successively repeated cycles, each cycle including at least one hydrogen production phase (H) from a low temperature electrolyte solution, followed by a low temperature electrolyte pushout phase (LH) in which the low temperature electrolyte is replaced with a cleaning solution, followed by at least one cleaning phase (L) in which the electrolysis electrodes of the reactor are cleaned, followed by a cleaning solution pushout phase (OL) in which the cleaning solution is replaced with a high temperature electrolyte solution, followed by at least one oxygen production phase (O) from the high temperature electrolyte, followed by a high temperature electrolyte pushout phase (LO) in which the high temperature electrolyte solution is replaced with a cleaning solution, followed by at least one cleaning phase (L) in which the electrolysis electrodes of the reactor are cleaned, followed by a cleaning solution pushout phase (HL) in which the cleaning solution is replaced with a low temperature electrolyte solution.

[0017] The system may include at least one hydrogen production inhibition phase (H-) between at least one hydrogen production phase from the low temperature electrolyte solution (H) and the low temperature electrolyte push-out phase (LH) and / or after the cleaning solution push-out phase (HL) and before a new hydrogen production (H) phase of a new cycle is initiated.

[0018] The system determines the duration of one or more of the phases and / or the entire electrolysis process by measuring the duration of the electrolysis cycle τ c (or any derivative thereof), and / or the number of reactors in the system, N s (or any derivative thereof), and / or the number of active reactors in the system, N a (or any derivative thereof), and / or the length / duration τ of the hydrogen production (H) phase. h (or any derivative thereof), and / or the length / duration τ of the (LO) and (OL) push lo (or any derivative thereof), and / or the length / duration τ of the (LH) and (HL) pusheslh (or any derivative thereof), and / or the length / duration of the oxygen-producing (O) phase τ o (or any derivative thereof), and / or the average length / duration τ of the leftover / cleaning (L) phase l (or any derivative thereof), and / or the average length / duration of the (H-)phase τ h- (or any derivative thereof).

[0019] The system determines the duration of one or more of the phases and / or the entire electrolysis process by the length / duration of the (LH) and (HL) pushes, τ lh (or any derivative thereof), (LO) and (OL) the length / duration of the push τ lo (or any derivative thereof), the length / duration of the hydrogen production (H) phase τ h (or any derivative thereof), the number of reactors in the system, N s (or any derivative thereof), and / or the number of active reactors in the system, N a (or any derivative thereof).

[0020] The system determines the duration of one or more of the phases and / or the entire electrolysis process by the length / duration τ of the hydrogen production (H) phase. h (or any derivative thereof), the length / duration of the oxygen production (O) phase τ o (or any derivative thereof), the average length / duration of the residue / cleaning (L) phase, τ l (or any derivative thereof), (LH) and (HL) the length / duration of the push τ lh (or any derivative thereof).

[0021] Optionally, but preferably in some embodiments, the duration of each of the hydrogen production (H), hydrogen production inhibition (H-), cleaning (L) and oxygen production (O) phases is substantially equal to a step duration multiplied by a natural number, the step duration being the duration of at least one of the push-out phases. The system may be configured such that the total duration of the cleaning phases (L) during each cycle is substantially equal to at least the step duration multiplied by 4 when the number of phase shifts between the reactors is 1, 2 or 3, and / or the step duration multiplied by 6 when the number of phase shifts between the reactors is 4, and / or the step duration multiplied by 10 when the number of phase shifts between the reactors is 5, and / or the duration of the total phase shift minus the duration of the two phases when the number of phase shifts between the reactors is greater than 5.

[0022] The system may be configured such that the total duration of the hydrogen production inhibition phase (H-) during each cycle is substantially equal to at least the step duration multiplied by 2 when the number of phase shifts between the reactors is 1, and / or the step duration multiplied by 5 when the number of phase shifts between the reactors is 2, and / or the step duration multiplied by 2 when the number of phase shifts between the reactors is 3, and / or the step duration multiplied by 3 when the number of phase shifts between the reactors is 4, and / or the step duration multiplied by 4 when the number of phase shifts between the reactors is of 5 phases, and / or the duration of the total phase shifts between the reactors minus the duration of one phase when the number of phase shifts between the reactors is greater than 5.

[0023] The system may be configured such that the total duration of a cycle is substantially equal to at least the step duration multiplied by 12 and the number of phase shifts between the reactors when the number of phase shifts between the reactors is one, and / or the step duration multiplied by 7 and the number of phase shifts between the reactors when the number of phase shifts between the reactors is two, and / or the step duration multiplied by 5 and the number of phase shifts between the reactors when the number of phase shifts between the reactors is three, and / or the step duration multiplied by 4 and the number of phase shifts between the reactors when the number of phase shifts between the reactors is between four and eight inclusive, and / or the step duration multiplied by 3 and the number of phase shifts between the reactors when the number of phase shifts between the reactors is greater than eight.

[0024] The system may be configured such that the total duration of the oxygen producing (O) phase(s) during each cycle is greater than the step duration multiplied by 2 and the number of phase shifts between the reactors minus the duration of one phase when the number of phase shifts between the reactors is one, and / or the step duration multiplied by the number of phase shifts between the reactors minus the duration of one phase when the number of phase shifts between the reactors is greater than one.

[0025] The system may be configured such that the difference between the total number of step durations in a cycle and the total number of step durations during the hydrogen production (H) phase divided by the number of phase shifts between the reactors minus the total number of step durations during the low temperature electrolyte push-out phase (LH) is at least substantially equal to 9 when the number of phase shifts between the reactors is 1, and / or 5 when the number of phase shifts between the reactors is 2, and / or 3 when the number of phase shifts between the reactors is 3 or 4, and / or 2 when the number of phase shifts between the reactors is between 5 and 8 inclusive, and / or 1 when the number of phase shifts between the reactors is greater than 8.

[0026] In some embodiments, the control system is configured to at least one of: supplying electrical power from the power source to an electrical power grid when a high power capacity of the power source is determined thereby; consuming electrical power from the electrical power grid when the power capacity of the power source is determined to be less than a predetermined intermediate power capacity level; deactivating all of the electrolysis processes performed by the plurality of reactors when the power capacity of the power source is determined to be less than a predetermined minimum power capacity level; adjusting the electrical current supplied to at least one of the plurality of reactors when it is determined thereby that a reduction in the power capacity of the power source may cause short-term fluctuations in the power supply; further adjusting a duration of at least one of the phases of the electrolysis process when it is determined thereby that a reduction in the power capacity of the power source may cause longer term fluctuations in the power supply; and further adjusting a duration of at least one of the phases and / or a sequence of phases of the electrolysis process when it is determined thereby that a reduction in the power capacity of the power source may substantially reduce the efficiency of the electrolysis process.

[0027] In some embodiments, at least one of the power sources, or all of the power sources, are renewable power sources. The control system may be configured to receive and process sensory data / signals indicative of changes in environmental conditions and, based thereon, predict possible changes in power capacity of the renewable power sources. Optionally, but preferably, in some embodiments, at least one of the power sources, or all of the power sources, are solar power sources and the control system is configured to receive and process weather forecast data and, based thereon, predict possible changes in power capacity.

[0028] The system, in some embodiments, includes a reservoir containing a high temperature electrolyte solution, a reservoir containing a low temperature electrolyte solution, a reservoir containing a cleaning solution, and an apparatus for controllably flowing the solutions between the reservoir and each of a plurality of reactors. The control system can be configured to flow the solutions from the reservoir to each of the plurality of reactors during each phase of the electrolysis process taking place therein.

[0029] The control system, in some embodiments, is configured to apply an electrical voltage across the electrolysis electrodes of each of the plurality of reactors only when a hydrogen-producing (H) phase of the electrolysis process is occurring, and to circulate the low temperature electrolyte solution between the low temperature electrolyte solution reservoir and the reactors undergoing the hydrogen-producing (H) phase of the electrolysis process.

[0030] The control system includes: during a low-temperature electrolyte push-out phase (LH), pushing the low-temperature electrolyte solution into the low-temperature electrolyte solution reservoir again by flowing a cleaning solution from the cleaning solution reservoir into the low-temperature electrolyte solution reservoir; during a hydrogen production blocking phase (H-), circulating the low-temperature electrolyte solution between the low-temperature electrolyte solution reservoir and the reactor without applying an electric voltage to the electrolysis electrodes thereof; during a cleaning phase (L), circulating the low-temperature electrolyte solution between the cleaning solution reservoir and the reactor from the electrolysis electrodes of the reactor to generate gaseous products. circulating a cleaning solution to clean the hot electrolyte residues; pushing the cleaning solution from the reactor and back into the cleaning solution reservoir by flowing the hot electrolyte solution from the hot electrolyte solution reservoir into the reactor during a cleaning solution push-out phase (OL); circulating the hot electrolyte solution between the hot electrolyte solution reservoir and each of the plurality of reactors during an oxygen production phase (O) of the electrolysis process; and pushing the hot electrolyte solution back into the hot electrolyte solution reservoir by flowing the cleaning solution from the cleaning solution reservoir into the hot electrolyte solution reservoir during a hot electrolyte push-out phase (LO). circulating a cleaning solution between the cleaning solution reservoir and the reactors that have completed the oxygen production phase to clean oxygen residues from the electrolysis electrodes of the reactors; pushing the cleaning solution from the reactors back into the cleaning solution reservoir during a cleaning solution push-out phase (HL) by flowing cold electrolyte solution from the cold electrolyte solution reservoir into the reactors; and circulating the cold electrolyte solution between the cold electrolyte solution reservoir and the reactors that have completed the oxygen production phase without applying an electric voltage to their electrolysis electrodes.

[0031] The system may be configured to maintain the cleaning solution in the cleaning solution reservoir at a temperature substantially less than the temperature of the hot electrolyte solution and substantially greater than the temperature of the cold electrolyte solution. The cleaning solution reservoir, in some embodiments, comprises one or more cold cleaning solution sub-reservoirs for the cold cleaning solution maintained at a temperature(s) greater than the temperature of the cold electrolyte solution, and one or more hot cleaning solution sub-reservoirs for the hot cleaning solution maintained at a temperature(s) less than the temperature of the hot electrolyte solution and greater than the temperature(s) of the cold cleaning solution. The control system may be configured to use the cold cleaning solution from the one or more cold cleaning solution sub-reservoirs during the hot electrolyte push-out phase (LO) and at least one cleaning phase (L) thereafter, and to use the hot cleaning solution from the one or more hot cleaning solution sub-reservoirs during the cold electrolyte push-out phase (LH) and at least one cleaning phase (L) thereafter.

[0032] The system in some embodiments comprises at least two of the low temperature cleaning solution sub-reservoirs, where the temperature of the low temperature cleaning solution maintained in the at least two low temperature cleaning solution sub-reservoirs is distributed between a temperature of the low temperature electrolyte solution and an intermediate temperature of the low temperature electrolyte solution and the high temperature electrolyte solution, and at least two of the high temperature cleaning solution sub-reservoirs, where the temperature of the high temperature cleaning solution maintained in the at least two high temperature cleaning solution sub-reservoirs is distributed between the intermediate temperature and the temperature of the high temperature electrolyte solution. The control unit may be configured to gradually increase the temperature of the cleaning solution flowed from the high temperature cleaning solution sub-reservoir to the reactor during a low temperature electrolyte push-out phase (LH) and to gradually decrease the temperature of the cleaning solution flowed from the low temperature cleaning solution sub-reservoir to the reactor during a high temperature electrolyte push-out phase (LO).

[0033] Each phase of the electrolysis process may include one or more steps, each of a fixed, predetermined time interval. The control system may be configured to determine the number of steps in each phase of the electrolysis based on at least one of the power capacity of the power source and a phase shift between the electrolysis processes performed by at least two of the reactors.

[0034] In another aspect, there is provided an electrolysis plant comprising two or more of the electrolysis systems disclosed above or below utilizing a single high temperature electrolyte reservoir, a single low temperature electrolyte reservoir, and one or more cleaning solution reservoirs, and a control system configured to sequence (LH), (L) and (OL) phases in one of the two or more electrolysis systems and sequence (LO), (L) and (HL) phases in at least another one of the two or more electrolysis systems.

[0035] In yet another aspect, a method of electrolysis is provided that includes performing an electrolysis process having a sequence of phases in a plurality of reactors, each of the reactors comprising an electrolysis electrode and performing an electrolysis process with a phase shift relative to at least another one of the plurality of reactors; monitoring changes in power capacity of one or more power sources used to perform the electrolysis process by the plurality of reactors, and based thereon, at least one of activating or deactivating one or more of the electrolysis processes performed by the plurality of reactors, adjusting a duration of at least one of the phases of the electrolysis process, adjusting power supplied from the one or more power sources to at least one of the plurality of reactors, and / or adjusting, removing or introducing at least one phase of the electrolysis process.

[0036] The method, in some embodiments, comprises performing an electrolysis process in a reactor during successively repeated cycles, each cycle comprising at least one hydrogen production (H) phase from a low temperature electrolyte solution, optionally followed and / or preceded by at least one hydrogen production inhibition phase (H-), followed by a low temperature electrolyte push-out phase (LH) in which the low temperature electrolyte is replaced with a cleaning solution, followed by at least one cleaning phase (L) in which the electrolysis electrodes of the reactor are cleaned, followed by a cleaning solution push-out phase (OL) in which the cleaning solution is replaced with a high temperature electrolyte solution, followed by at least one oxygen production (O) phase from a high temperature electrolyte, followed by a high temperature electrolyte push-out phase (LO) in which the high temperature electrolyte solution is replaced with a cleaning solution, followed by at least one cleaning phase (L) in which the electrolysis electrodes of the reactor are cleaned, followed by a cleaning solution push-out phase (HL) in which the cleaning solution is replaced with a low temperature electrolyte solution.

[0037] The method can include setting a duration of each of the hydrogen production (H), hydrogen production inhibition (H-), cleaning (L), and oxygen production (O) phases to be substantially equal to a step duration multiplied by a natural number, the step duration being a duration of at least one of the push-out phases.

[0038] The method, in some embodiments, includes setting the total duration of the cleaning phases (L) in each cycle to be substantially equal to at least the step duration by 4 when the number of phase shifts between reactors is 1, 2 or 3, and / or the step duration by 6 when the number of phase shifts between reactors is 4, and / or the step duration by 10 when the number of phase shifts between reactors is 5, and / or the duration of the total phase shift minus the duration of two phases when the number of phase shifts between reactors is greater than 5.

[0039] The method, in some embodiments, includes setting the total duration of the hydrogen production inhibition phase (H-) during each cycle to be substantially equal to at least the step duration multiplied by 2 when the number of phase shifts between the reactors is one, and / or the step duration multiplied by 5 when the number of phase shifts between the reactors is two, and / or the step duration multiplied by 2 when the number of phase shifts between the reactors is three, and / or the step duration multiplied by 3 when the number of phase shifts between the reactors is four, and / or the step duration multiplied by 4 when the number of phase shifts between the reactors is of five phases, and / or the duration of the total phase shifts between the reactors minus the duration of one phase when the number of phase shifts between the reactors is greater than five.

[0040] The method, in some embodiments, includes setting the total duration of the cycle to be substantially equal to at least the step duration multiplied by 12 and the number of phase shifts between the reactors when the number of phase shifts between the reactors is one, and / or the step duration multiplied by 7 and the number of phase shifts between the reactors when the number of phase shifts between the reactors is two, and / or the step duration multiplied by 5 and the number of phase shifts between the reactors when the number of phase shifts between the reactors is three, and / or the step duration multiplied by 4 and the number of phase shifts between the reactors when the number of phase shifts between the reactors is between four and eight inclusive, and / or the step duration multiplied by 3 and the number of phase shifts between the reactors when the number of phase shifts between the reactors is greater than eight.

[0041] The method, in some embodiments, includes setting a total duration of the oxygen producing (O) phase(s) during each cycle to be substantially greater than the step duration multiplied by 2 and the number of phase shifts between the reactors minus the duration of one phase when the number of phase shifts between the reactors is one, and / or the step duration multiplied by the number of phase shifts between the reactors minus the duration of one phase when the number of phase shifts between the reactors is greater than one.

[0042] The method, in some embodiments, includes setting the subtraction of the total number of step durations during the low temperature electrolyte push-out phase (LH) from the division of the difference between the total number of step durations in the cycle and the total number of step durations during the hydrogen production (H) phase by the number of phase shifts between the reactors to be substantially equal to at least 9 when the number of phase shifts between the reactors is 1, and / or 5 when the number of phase shifts between the reactors is 2, and / or 3 when the number of phase shifts between the reactors is 3 or 4, and / or 2 when the number of phase shifts between the reactors is between 5 and 8 inclusive, and / or 1 when the number of phase shifts between the reactors is greater than 8.

[0043] The method may include at least one of: supplying electrical power from a power source to an electrical power grid when a high power capacity of the power source is thereby determined; consuming electrical power from the electrical power grid when it is determined that the power capacity of the power source is less than a predetermined intermediate power capacity level; deactivating all of the electrolysis processes performed by the plurality of reactors when it is determined that the power capacity of the power source is less than a predetermined minimum power capacity level; adjusting the electrical current supplied to at least one of the plurality of reactors when it is determined that a reduction in the power capacity of the power source may cause short-term fluctuations in the power supply; further adjusting a duration of at least one of the phases of the electrolysis process when it is determined that a reduction in the power capacity of the power source may cause longer term fluctuations in the power supply; and further adjusting a duration of at least one of the phases and / or a sequence of phases of the electrolysis process when it is determined that a reduction in the power capacity of the power source may substantially reduce an efficiency of the electrolysis process.

[0044] At least one of the power sources, or all of the power sources, may be renewable power sources, and the method may include receiving and processing sensory data / signals indicative of changes in environmental conditions, and predicting a potential change in power capacity of the renewable power sources based thereon. In a possible embodiment, at least one of the power sources, or all of the power sources, may be solar power sources, and the method may include receiving and processing weather forecast data, and predicting a potential change in power capacity based thereon.

[0045] The method may include flowing solutions from at least one of a reservoir containing a high temperature electrolyte solution, a reservoir containing a low temperature electrolyte solution, and a reservoir containing a cleaning solution to each of a plurality of reactors during each phase of an electrolysis process performed therein.

[0046] The method, in some embodiments, includes applying an electrical voltage across the electrolysis electrodes of each of a plurality of reactors only when performing a hydrogen production (H) phase of the electrolysis process; circulating a cold electrolyte solution between a cold electrolyte solution reservoir and the reactor performing the hydrogen production (H) phase of the electrolysis process; during a cold electrolyte push-out phase (LH), pushing the cold electrolyte solution back into the cold electrolyte solution reservoir by flowing a cleaning solution from the cleaning solution reservoir into the cold electrolyte solution reservoir; during a hydrogen production blocking phase (H-), circulating the cold electrolyte solution between the cold electrolyte solution reservoir and the reactor without applying an electrical voltage to their electrolysis electrodes; during a cleaning phase (L), circulating a cleaning solution between the cleaning solution reservoir and the reactor to clean gas production residues from the electrolysis electrodes of said reactor; pushing the cleaning solution from the reactor and back into the cleaning solution reservoir by flowing hot electrolyte solution from the hot electrolyte solution reservoir into the reactor during an oxygen production phase (O) of the electrolysis process; circulating the hot electrolyte solution between the hot electrolyte solution reservoir and each of the plurality of reactors during a hot electrolyte push-out phase (LO) pushing the hot electrolyte solution back into the hot electrolyte solution reservoir by flowing the cleaning solution from the cleaning solution reservoir into the hot electrolyte solution reservoir during a hot electrolyte push-out phase (LO) pushing the cleaning solution from the reactor and back into the cleaning solution reservoir by flowing cold electrolyte solution from the cold electrolyte solution reservoir into said reactor during a cleaning solution push-out phase (HL); maintaining the cleaning solution in the cleaning solution reservoir at a temperature substantially less than a temperature of the hot electrolyte solution and substantially greater than a temperature of the cold electrolyte solution;maintaining a low temperature cleaning solution contained in one or more low temperature cleaning solution sub-reservoirs at temperature(s) greater than the temperature of the low temperature electrolyte solution; maintaining a high temperature cleaning solution contained in one or more high temperature cleaning solution sub-reservoirs at temperature(s) less than the temperature of the high temperature electrolyte solution and greater than the temperature(s) of the low temperature cleaning solution; using a low temperature cleaning solution from one or more low temperature cleaning solution sub-reservoirs during a high temperature electrolyte push-out phase (LO) and during at least one cleaning phase (L) thereafter; using a high temperature cleaning solution from one or more high temperature cleaning solution sub-reservoirs during a low temperature electrolyte push-out phase (LH) and during at least one cleaning phase (L) thereafter; a low temperature electrolyte solution having a temperature distributed between an intermediate temperature of the low temperature electrolyte solution and the high temperature electrolyte solution; setting a temperature of the low temperature cleaning solution contained in at least two of the hot cleaning solution sub-reservoirs, and setting a temperature of the high temperature cleaning solution contained in at least two of the hot cleaning solution sub-reservoirs distributed between said intermediate temperature and the temperature of the high temperature electrolyte solution; gradually increasing the temperature of the cleaning solution flowed from the high temperature cleaning solution sub-reservoirs to the reactor during a low temperature electrolyte push-out phase (LH), and gradually decreasing the temperature of the cleaning solution flowed from the low temperature cleaning solution sub-reservoirs to the reactor during a high temperature electrolyte push-out phase (LO); setting each phase of the electrolysis process to have one or more steps, each of fixed predetermined time intervals, and determining the number of steps in each phase of the electrolysis based on at least one of the power capacity of the power source and the phase shift between the electrolysis processes performed by at least two of the reactors;performing a sequence of (LH), (L) and (OL) phases in one electrolysis system and a sequence of (LO), (L) and (HL) phases in at least another electrolysis system, the electrolysis systems utilizing a single high temperature electrolyte reservoir, a single low temperature electrolyte reservoir and one or more cleaning solution reservoirs;

[0047] In order to understand the subject matter disclosed herein and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which the features shown are intended, unless otherwise implicitly indicated, to represent only some embodiments of the disclosed subject matter. In the drawings, like reference numerals are used to indicate corresponding parts. [Brief description of the drawings]

[0048] [Figure 1] 1A-1C are schematic diagrams illustrating plant (e.g., electrolysis) power management schemes according to some possible embodiments, where FIG. 1A illustrates a schematic of a plant management system and FIGS. 1B and 1C are flow charts of possible power management schemes. [Diagram 2] 2A-2J are schematic diagrams illustrating an electrolysis cycle according to some possible embodiments. [Diagram 3] 3A-3E are diagrams illustrating the rules and assumptions to be met by an electrolysis control scheme according to some possible embodiments. [Figure 4] 4A-4C are diagrams illustrating some conditions that may be followed by an electrolysis control scheme according to some possible embodiments. [Diagram 5] 5A-5C are diagrams illustrating control rules that can be used for an electrolysis process according to some possible embodiments. [Figure 6] 6A-6F are diagrams illustrating control rules that can be used for an electrolysis process according to some possible embodiments. [Figure 7] 7A and 7B are diagrams illustrating the activation of a new Set during operation of the electrolysis system according to some possible embodiments. [Figure 8] 8A-8C are diagrams illustrating deactivation of Set during operation of the electrolysis system according to some other possible embodiments. [Figure 9] FIG. 9 shows a schematic diagram of a plant according to some possible embodiments. [Figure 10] FIG. 10 is a diagram illustrating the phases of the electrolysis process carried out in the plant illustrated in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0049] One or more specific and / or alternative embodiments of the present disclosure are described below with reference to the drawings, which should be considered in all respects as merely illustrative and not restrictive in any manner. It will be apparent to those skilled in the art that these embodiments can be practiced without such specific details. In order to provide a concise description of these embodiments, not all features or details of the actual implementation are described in detail herein. The elements shown in the drawings are not necessarily to scale or in correct proportion, which are not important. Instead, the emphasis is on clearly illustrating the principles of the present invention so that those skilled in the art can make and use electrolysis techniques once they understand the principles of the subject matter disclosed herein. The present invention may be provided in other specific forms and embodiments without departing from the essential characteristics described herein.

[0050] Various "green" power sources behave differently with respect to their power profiles: for example, solar-based power sources have a typical fixed daily operating profile that varies between seasons in addition to fast power production variations that occur as a result of diurnal weather variations, e.g., due to clouds, that directly affect the availability and / or intensity of the produced electrical power.

[0051] In an E-TAC system, for example, if the available power supply can be predicted in advance, it can be used by the power management system and by the E-TAC control system for optimization. For solar energy sources, predicting available power can be both trivial (e.g., no power at night) or extremely complex (using real-time satellite imagery or aerial photography to predict cloud cover in the next 5 minutes over the PV field / panel). When cloud cover can change in seconds, the output from the photovoltaic (PV) array power fluctuates just as fast.

[0052] Wind energy output also varies greatly, but because wind turbines have large inertia, they respond slower to changing wind strength, so the power management system can rely on wind change readings to determine the response required.

[0053] In addition to changes in the renewable power resource itself, the available power supply used for electrolysis, e.g., to produce hydrogen, may depend on other factors as well. For example, if the feed-in price of electricity is high, it may be more economical to divert more of the power generated by the renewable power plant (e.g., PV arrays, wind farms, etc.) to the electric grid. On the other hand, if grid electricity prices fall low enough, it may be economical to draw additional power from the electric grid. As with power availability, these / other factors may vary the power supplied to an electrolysis system, e.g., for hydrogen production, in predictable (e.g., higher electricity prices during January) and less predictable (e.g., gas power plant failure due to frozen pipes) ways (e.g., day / night electricity prices).

[0054] The present application provides techniques for optimizing the operation of an E-TAC electrolysis system under intermittent power conditions. The techniques disclosed herein are based in some embodiments on various responses corresponding to the response time and magnitude of power changes. For example, solar power has a typical fixed daily operating profile that changes between seasons in addition to fast power changes that occur as a result of diurnal weather changes, e.g., due to clouds, that directly affect power production capacity. Prediction of such conditions may involve weather forecasts and real-time aerial photography, and such fast changes and related predictions require fast power regulation responses from the power management system being used.

[0055] The embodiments disclosed herein provide techniques for coupling between a renewable (e.g., solar) power source and an E-TAC electrolysis system that enables the needed “look-ahead” prediction of continuous and / or efficient operation of the E-TAC electrolysis system to mitigate intermittency of power supply from the renewable power source.

[0056] 1A illustrates generally a plant system 20 configured to provide power to a plant 15 (e.g., an electrolysis system) from a renewable power source (e.g., a solar power plant) 11 and / or an electrical grid infrastructure 14. If the renewable power source 11 is a DC (direct current) power source, it may be converted to AC electrical power by one or more DC-AC (alternating current) converters 13. One or more power regulators 18 may be used to regulate the use of electrical power generated by the renewable power source 11 and / or a source of electrical power supplied to the plant 15 from multiple different sources, such as the renewable power source 11 and the electrical grid 14.

[0057] The control system 16 is configured and operable to receive and process sensory data / signals 17d, e.g., from one or more sensor devices 17, indicative of environmental conditions (e.g., intensity of radiation and / or angle of incidence, ambient temperature, wind direction / speed, etc.) that may act on the electric power capacity of the renewable electric power source 11. Additionally or alternatively, the control system 16 may receive auxiliary data 16d related to the renewable electric power source 11 and / or other electric power sources, e.g., general publicly available data, such as weather forecasts, satellite weather imagery, current electric power price information, or policies (e.g., power may not be directed for E-TAC operation between 2:00-4:00 PM). For example, the auxiliary data 16d may be received from external sources, such as data / computer networks / internet, cellular networks, satellites, etc. The control system 16 may be configured to forecast the planned electric power capacity of the renewable electric power source 11 to facilitate optimal operation of the plant / electrolysis system 15. Based on the received and processed sensory data 17d and / or auxiliary data 16d, the control system 16 generates control data / signals 18c for regulating the use of the electrical power generated by the renewable power source 11 and / or control data / signals 15c for adjusting the operating state and / or conditions of the plant 15.

[0058] The plant 15, in some embodiments, comprises multiple subsystems / reactors, Set1, Set2, ..., Set i, generally referred to herein as Sets. The plant 15 may further have one or more electrical power conversion units 19, e.g., AC-DC converters and / or DC-DC converters. The control system 16 may be configured to use one or more algorithms for the generation of the control data / signals 18c / 15c, e.g., based on the power management control processes 10 and 23 shown in Figs. 1B and 1C, respectively. The control system 16 may utilize one or more processors and memories (not shown) to process various data inputs and generate the respective control data / signals 18c / 15c. Optionally, the control system 16 is implemented as a state machine with multiple inputs, some of which are internal to the system (e.g., the state of charge of the Sets, the instantaneous power levels supplied to each Set, etc.) and some of which are external, such as "look-ahead" data (e.g., production requirements and power availability for the next 10 minutes, etc.). The control system 16 / state machine may be configured to use that data to make decisions about the use of electrical power generated by the renewable power sources 11 at any given time and / or to determine the best action to take to adjust the operating state / conditions of the Set of plants 15.

[0059] 1B is a flow chart illustrating a power management process 23 that can be used by the control system 16 according to some possible embodiments. In this particular and non-limiting example, the power management process 23 relies only on the renewable power capacity (q1) of the renewable power source 11, but in possible embodiments, additional data and information can be used, as exemplified below. If the renewable power source 11 is operating at a defined high capacity level (q2), the control data / signal 18c from the control system 16 can instruct the power regulator 18 to supply a portion of the electric power from the renewable power source 11 to the plant 15 and another portion of it to the electric grid 14 (q3). If the renewable power source 11 is producing electric power at a capacity less than the defined high capacity level and greater than the defined medium capacity level (q4), the control data / signal 18c from the control system 16 can instruct the power regulator 18 to supply all of the electric power from the renewable power source 11 to the plant 15 (q5).

[0060] If the renewable power sources 11 are operating at a capacity less than a specified medium capacity level and greater than a specified low capacity level (q6), control data / signals 18c from the control system 16 can instruct the power regulator 18 to supply all of the electrical power from the renewable power sources 11 to the plant 15 and, optionally, consume electrical power from the electrical grid 14 to operate the plant 15, and / or control signals / data 15c from the control system 16 can be used to instruct the plant 15 to adjust the power consumption of the Set of plants 15 to comply with the power supply limits (q7). If the renewable power source 11 is operating at a capacity less than a specified low capacity level and greater than a specified minimum capacity level (q8), control data / signals 18c from the control system 16 may be used to instruct the power regulator 18 to supply all of the electrical power from the renewable power source 11 to the plant 15 and, optionally, consume electrical power from the electrical grid 14 to operate the plant 15, and control signals / data 15c from the control system 16 may be used to instruct the plant 15 to turn off one or more of Set (and / or subsystems Sub i) of the plant 15 to comply with the new power supply limits (q9). If the electrical power capacity of the renewable power source 11 is less than a defined minimum capacity level, control data / signal 18c from the control system 16 may be used to instruct the power regulator 18 to consume all electrical power required for the operation of the plant 15 from the electrical grid 14, or alternatively, control data / signal 15c from the control system 16 may be used to instruct the plant 15 to pause all / substantial operation of the plant 15 (q10).

[0061] Where 100% power represents an optimal operating point for the plant 15, e.g., an E-TAC system, the control system 16 may be configured to utilize several strategies for handling changes in the electrical power supply from the renewable power source 11, depending on the level of change and the time given for the system to adjust (which in the worst case may be immediate), as well as the rate of change (e.g., a 20% drop in 2 minutes is different from the same drop over 20 minutes).

[0062] FIG. 1C shows a flow chart of a plant (e.g., electrolysis) management process 10 according to some possible embodiments. The process 10 may start in a steady operating state (s1) where the plant is operated with a full power supply at its optimal production rate. If the plant 15 is not in operation or has been paused previously (e.g., in step q10 of process 23 and / or step s9 of process 10), it may be resumed and / or start up one or more of the Set (and / or subsystems Sub i) of the plant 15. Whenever a power supply change is encountered (s2, e.g., a change in electrical current / voltage), one or more conditions are examined (s3, s5, s7, ...) to determine an optimal adjustment in the operation of the plant 15. Minor short-term fluctuations in the power supply ( <T 1 , e.g., less than 5% of the time required to complete the electrolysis cycle, or less than the time required for three steps of the electrolysis cycle) (s3), and / or a first predefined threshold THR 1 For power supply changes smaller than s4 (e.g., <20%), the system may vary the applied electrical current / voltage in the active electrolysis reactor Set (and / or subsystem Sub i) accordingly (s4).

[0063] Longer-term changes ( <T 2, e.g., less than 15% of the time required to complete the electrolysis cycle, or less than the time required for 10 steps of the electrolysis cycle), and / or a power supply magnitude change (s5), e.g., greater than a second predefined threshold THR 2 A power supply change smaller than 0.1 V (e.g., <40%) may require, in addition to changing the electrical current supplied to Set, also modifying / reducing the step duration of the electrolysis process (s6, to accommodate the change in electrical charge resulting from the current change).

[0064] Larger changes in duration and / or power delivery magnitude (s7, <T 3 , e.g., less than 30% of the time required to complete the electrolysis cycle, or less than the time required for 20 steps of the electrolysis cycle), and / or a third predefined threshold THR 3 Power supply magnitude changes smaller than 0.1% (e.g. smaller than 60%, which may cause reduced efficiency by equipment such as pumps operating for long cycles / time intervals at low electrical current, which may entail malfunctions and / or damage to system components / equipment) can be mitigated by effecting further changes in the system operation sequence (s8) by modifying the number of steps per cycle and / or the number of simultaneously active Set (and / or subsystems Sub i) in the plant 15, as required according to the power capacity level of the renewable power source 11.

[0065] For very large changes in the electrical power supply from the renewable power source 11 and / or for very large changes in the duration of the change, the system may shut down one or more of the Set (and / or sub-subsystems Sub i, s9) of the system and later restart them, thus adjusting the Set (and / or sub-subsystems Sub i) participating in production to the available power capacity of the renewable power source 11.

[0066] Long periods (s10, several hours, e.g., solar power termination at night) may also require special care (s11) to conserve heat in the tank, which can be handled by the usage of the electric grid power 14 to compensate for heat loss. Another option is to utilize the tank insulation to conserve most of the heat and to use the exothermic nature of the TAC phase. To utilize the exothermic oxygen production reaction, when the system goes to standby / off state, one or more of the Sets (and / or subsystems Sub i) will be shut down after the cleaning step (L phase shown in FIG. 2D) and before the TAC (exothermic) phase starts (FIG. 2E). This will provide that the electrodes will release heat during the TAC phase (phase O shown in FIG. 2F) after the power supply to the plant 15 is restored. For example, when restarting the plant system 15, the idled Sets will go to the TAC phase (phase O shown in FIG. 2F) and the generated heat will be released into the high temperature tank and thereby used to compensate for minor heat losses during this shutdown (e.g., several hours at night).

[0067] In some embodiments, the process 10 is adapted to adjust the power consumption of the plants and / or the operating states / conditions of the Set of plants according to the following table:

[0068] TIFF2025510509000002.tif48170

[0069] The following description provides possible embodiment techniques for controlling the E-TAC sequence of the electrolysis plant 15 to compensate for the electric power supply changes of the renewable power source 11. In general, for a given number of Sets, each comprising one or more electrolysis reactors, there are several specific possibilities for the E-TAC sequence in optimal stabilized operation. These possibilities may involve different numbers of steps during a complete operating cycle and / or different numbers of simultaneous H 2The optimized sequence allows for optimized power and energy distribution for the Set. In this regard, it is noted that the optimized sequence according to possible embodiments is configured to keep the system in a "steady state", i.e., hydrogen is produced at a steady rate, various components of the system, such as pumps, are operating at constant speeds, etc.

[0070] In E-TAC, hydrogen (H 2 ) and oxygen (O 2 ) are produced in different phases. Electricity (power) is drawn for the electrolysis itself only during the hydrogen production phase (H in Figures 2A-2J). Thus, a single "reactor" / Set, in which the E-TAC reaction occurs, will oscillate between the phases of the electrolysis process / cycle. Similarly, different electrolytes (e.g., cold, hot, warm) will need to be "pushed" into and / or out of the reactor / Set at different times in the electrolysis process / cycle. In a multi-Set system (e.g., multiple reactors electrically connected in series and hydraulically connected in parallel), electrical power and in / out flows to / from the reactor / Set can be balanced to keep the system at steady state as a whole.

[0071] Thus, the electrolysis plant 15 in the embodiment of the present application produces hydrogen (H 2 ) For gas production, one or more high temperature tanks can be included for storing and delivering high temperature electrolyte solution at a temperature generally greater than 60° C. or greater than 90° C., but optionally within the range of room temperature (e.g., 23° C.-30° C.) and up to 200° C. Optionally, the temperature of the high temperature electrolyte solution is within the range of 20° C.-200° C., but in possible embodiments is about 80° C.-150° C.

[0072] The electrolysis plant 15 is configured to generate oxygen (O 2 ) gas production, the electrolysis plant 15 may also include one or more cryogenic tanks for storing and supplying cold electrolyte solution at a temperature generally less than 45° C. (but above its freezing temperature), optionally about 30° C. The electrolysis plant 15 may also include one or more wash tanks (also referred to herein as tails) for storing and supplying warm electrolyte solution at one or more intermediate temperatures, generally in the range between the temperatures of the hot electrolyte solution and the cold electrolyte solution, for washing the Set / reactor of the electrolysis plant 15 during one or more intermediate steps between the gas production stages / phases of the electrolysis process.

[0073] Optionally, different solutions may be used for the hot electrolyte solution, the cold electrolyte solution, and / or the warm / wash solution during different stages of the electrolysis process. However, because the liquids in the different tanks / reservoirs mix over time (e.g., they come into contact during the "push" phase), the liquids will eventually have the same chemical composition, but at different temperatures. Thus, in a possible embodiment, the same electrolyte solution is used for the hot and cold electrolyte solutions and the warm / wash solution.

[0074] Optionally, but preferably in some embodiments, the electrolyte solution is an aqueous solution that includes water and, optionally, at least one water-soluble solvent, such as an alcoholic material (e.g., ethanol). The electrolyte solution can be any known in the art, but should generally be of basic pH (e.g., pH>7), although alkaline / basic electrolytes may also work (e.g., NaOH). Optionally, but preferably in some embodiments, high concentration (5M) KOH is utilized for the hot and cold electrolyte solutions, as well as the warm / wash solution.

[0075] To simplify operation, the plant system 15 in some embodiments employs a uniform timing / "clock" rule, i.e., the plant system 15 is operated in steps, each having a fixed length / duration. The length of a step is determined in some embodiments by the shortest "action", i.e., the action that "pushes" (in the reactor) electrolyte from the previous step by the electrolyte of the next step (into the appropriate pipes). In some embodiments, the control system 16 can vary the step length / duration within some tolerance margin, which allows some flexibility (e.g., it allows some variation in the electrical power supplied to the system).

[0076] 2A-2J, in some embodiments, each Set of plants 15 may be changed to the following sequence of operational phases: Phase H shown in Figure 2A: In this phase (H), hydrogen (H 2 ) is obtained from cathode C, which is charged by a power source (e.g., electrical power converter 19 of plant 15), i.e., electrical power is supplied to the electrodes (i.e., anode-A and cathode-C) while low temperature electrolyte (e.g., <40°C) is circulated between the Set / reactor and the low temperature tank. Phase H- shown in FIG. 2B: (also referred to herein as hydrogen production inhibition phase) In this phase, the electrical power (12) supply is disconnected (off) from electrodes A and C and the cold electrolyte continues to circulate between the Set / reactor and the cold tank. This phase is needed to remove hydrogen residues left in the reactor / Set. Phase LH shown in Figure 2C: In this phase, cold electrolyte is pushed from inside the Set / reactor into the cold tank and at the same time, warm electrolyte (e.g. <80°C and >40°C) from the tailings tank is pushed into the Set / reactor simultaneously. Phase L shown in Figure 2D: In this phase, the electrolyte is evaporating residual gas bubbles, e.g. H from the Set / reactor.2 The machine goes around the set / reactor and the tailings tank to clean / remove. Phase OL shown in FIG. 2E: In this phase, electrolyte from the Set / reactor is pushed into the tailings tank and at the same time, hot electrolyte (e.g., >90° C.) from the hot tank is pushed into the Set / reactor. Phase O shown in Figure 2F: In this phase, oxygen (O 2 ) is obtained from Anode A during its chemical discharge process while circulating the hot electrolyte through the Set / reactor. Phase LO shown in Figure 2G: In this phase, electrolyte is pushed from the Set / reactor into the hot tank by warm electrolyte from the tailings tank. Phase L shown in FIG. 2H: In this phase, the electrolyte is evacuated by residual gas bubbles, e.g. O from the reactor. 2 Again, the water goes around the Set / reactor and the tailings tank to clean / remove the Phase HL shown in Figure 2I: In this phase, the electrolyte from the Set / reactor is pushed to the dregs tank so that it is replaced with the cold electrolyte from the cold tank. Phase H- shown in FIG. 2J: In this phase, the low temperature electrolyte starts to circulate between the Set / reactor and the low temperature tank. Phase H shown in FIG. 2A: The electrical power supply (12) is switched on and a new electrolysis cycle begins.

[0077] In some embodiments, two or more consecutive L-step phases may be performed in the sequence. Further, in possible embodiments, the system may include two or more residue tanks (e.g., one or more high-temperature residue tanks and one or more low-temperature residue tanks). In possible embodiments, the power source 12 is configured to supply an electrical voltage generally greater than 1.5 volts to the "A" and "C" electrodes, although higher voltage levels may likewise be used. For example, in embodiments that utilize multiple electrolysis cells in each Set, the voltage of the power source 12 may be several hundred volts (e.g., 800 volts). The electric current between the "A" and "C" electrodes during the H (hydrogen production) phase (illustrated in FIG. 2A) generally depends on what depends on the size of the (one or more) electrolysis cells used. In possible embodiments, the current density may be in the range of 50 - 200 mA / cm 2 ². The "A" and "C" electrodes may be made of a conductive material.

[0078] FIG. 9 schematically shows a plant system 15 according to some possible embodiments. In this particular and non-limiting example, the plant system 15 comprises a plurality of subsystems Sub1, Sub2,..., Sub n (n > 0 is an integer). As illustrated, each subsystem Sub i (0 < i ≤ n is an integer) comprises a plurality of Sets / reactors, Set1, Set2,..., Set k (k > 1 is an integer), and each Set / reactor, Set j (1 < j ≤ k is an integer) is configured to perform an electrolysis process such as those disclosed herein and is operable.

[0079] Thus, the plant 15 may comprise a hot tank used to hold a hot electrolyte solution and supply it to the subsystem Sub i via a hot electrolyte line Lh, a cold tank used to hold a cold electrolyte solution and supply it to the subsystem Sub i via a cold electrolyte line Lc, and one or more washing tanks HW / CW for holding a washing solution and supplying it to the subsystem Sub i via a washing line Lw. Thus, each Set / reactor, Set j, may be fluidly communicated with the hot electrolyte line Lh by a controlled hot valve Vh, with the cold electrolyte line Lc by a controlled cold valve Vc, and with the washing line Lw by a controlled washing valve Vw. Thus, each Set / reactor, Set j, can receive a respective electrical power control 15e data / signal for switching the electrical connection of each Set / reactor to its electrodes of the electrical power source (12 in FIG. 1A), and / or a respective Seq control management control signal 15c for managing the state of each Set / reactor's high temperature valve Vh, low temperature valve Vc, and wash valve Vw.

[0080] In possible embodiments, the Set / reactor, Set j, of each subsystem Sub i is operated to perform the electrolysis process disclosed herein such that each Set / reactor, Set j, of subsystem Sub i is in different phases of the electrolysis process illustrated in Figures 2A-2J. Optionally, but preferably in some embodiments, the Set / reactor, Set j, of each subsystem Sub i is performing the electrolysis process illustrated in Figures 2A-2J with a predefined phase shift between them. Return lines, pumps, piping, and other components used to circulate the hot, cold, and cleaning solutions through the Set / reactor, Set j, are not shown in Figure 9 for simplicity, but they can be easily determined and implemented by the average practitioner based on the disclosure of this application.

[0081] The plant system 15 comprises one or more hot cleaning tanks HW for holding a hot cleaning solution and one or more cold cleaning tanks CW for holding a cold cleaning solution. Optionally, but preferably in some embodiments, the temperatures of the cleaning solutions stored in the hot cleaning tanks HW and the cold cleaning tanks CW are substantially uniformly distributed between the temperatures of the hot electrolyte solution stored in the hot tank and the cold electrolyte solution stored in the cold tank. In this way, the system 15 can gradually change the temperature of the Set / reactor, Set j, between the temperatures of the cold electrolyte solution and the hot electrolyte solution by gradually increasing or decreasing the temperature of the cleaning solution used to clean the electrolysis electrodes during the oxygen production phase and the hydrogen production phase of the electrolysis process.

[0082] Thus, the plant system 15 further comprises a hot cleaning line Lhw connected to the hot cleaning tank(s) HW for supplying the subsystem Sub i with a hot cleaning solution via a respective controllable valve Vhw, and a cold cleaning line Lcw connected to the cold cleaning tank(s) CW for supplying the subsystem Sub i with a cold cleaning solution via a respective controllable valve Vcw. The control system 16 thus comprises a 6hw for connecting each subsystem Sub i (i=1, 2, 3, ...) either to the hot cleaning tank(s) HW or to the cold cleaning tank(s) CW according to the electrolysis process phase communicated therein. i Signal or 6cw i In some embodiments, the control system is configured to generate a control signal 6hw such that whenever one of the subsystems Sub x is connected to the hot cleaning line Lhw (to the HW tank), at least another one of the subsystems Sub y (where x ≠ y, x, y ∈ 1, 2, 3, ...) is connected to the cold cleaning line Lcw (to the CW tank). i and 6cw i The method is configured to generate

[0083] In some embodiments, the plant 15 includes a plurality of hot washing tanks HW, collectively referred to herein as hot washing tanks HW, in fluid communication with the hot washing solution line Lhw. 1 , H.W. 2 , ..., H.W. M (M>0 is an integer). Thus, the hot cleaning tanks HW may use piping and controlled valves (not shown) to enable selection of at least one of the hot cleaning tanks HW for supplying hot cleaning solution therefrom to the hot solution line Lhw utilizing control signals 15hi generated by the control system 16. In some embodiments, the plant 15 includes multiple cold cleaning tanks CW, collectively referred to herein as cold cleaning tanks CW, in fluid communication with the cold solution line Lcw. 1 , C.W. 2 , ..., C.W. M Thus, the cold cleaning tanks CW may use plumbing and controlled valves (not shown) to enable selection of at least one of the cold cleaning tanks CW for supplying cold cleaning solution therefrom to the cold solution line Lhw, utilizing control signals 15ci generated by the control system 16.

[0084] The temperature of the cleaning solution maintained in the multiple hot and cold cleaning tanks HW and CW may be distributed between the temperature of the cold electrolyte solution in the cold tank and the temperature of the hot electrolyte solution in the hot tank. For example, in an embodiment utilizing a single cleaning solution tank, the temperature of the cleaning solution may be distributed between the high temperature (T h ) electrolyte solution and the low temperature of the cryogenic tank (T c ) Average temperature of electrolyte solution (T h +T c In an embodiment utilizing two cleaning (i.e., hot and cold) tanks, the system may maintain the cold cleaning solution in the cold cleaning tank CW at about T ch and high-temperature cleaning solution in the high-temperature cleaning tank HW. hcThe temperature range between the hot and cold electrolyte solutions is set to three (T c ⇔T ch ), (T ch ⇔T hc ) and (T hc ⇔T h ) (e.g., uniformly).

[0085] Similarly, if the plant system 15 includes two low-temperature cleaning tanks CW and two high-temperature cleaning tanks HW, the system includes two low-temperature cleaning tanks CW and HW. 1 and C.W. 2 The washing solution in each c+ and T ch In order to maintain the HW 1 and H.W. 2 The washing solution in each hc and T h- In order to maintain the temperature range between the hot and cold electrolyte solutions at 5°C, the c ⇔T c+ ), (T c+ ⇔T ch ), (T ch ⇔T hc ), (T hc ⇔T h- ) and (T h- ⇔T h ). The states of the various controlled valves shown in the figure, as well as other components of the system, may be transmitted via control signals (e.g., 15c, 6hw, 15i, 15j, 15m, 15n, 15m ...m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, 15m, i and / or 6cw i ) can be controlled by

[0086] The control system 16 of the plant 15 generally comprises one or more processors 16c and memory 16m configured and operable to store program code and / or other data required to execute plant management procedures and to generate control data / signals required to operate the plant 15, such as Set valve control 15c and electrical power control 15e data / signals (collectively referred to herein as 15c / e), high temperature 15hi and / or low temperature 15ci sub-tank selection data / signals (collectively referred to herein as 15hi / ci), high temperature 15wh and / or low temperature 15wc sub-tank selection data / signals (collectively referred to herein as 15wh / c), power management / regulation data / signals 18c, and / or other indications / alarms and / or information related to the operation and status of the electrolysis process performed thereby.

[0087] In some embodiments, the control system 16 comprises a power management module 16p configured and operable to implement various power management procedures, such as, but not limited to, a power management process 23 illustrated in the flowchart of Figure 1B. In this particular and non-limiting example, the power management module 16p is configured and operable to generate power management / regulation data / signals 18c for the power regulator(s) 18 (shown in Figure 1A) of the plant 15.

[0088] The control system 16 comprises a sequence (Seqs) management module 16s configured and operable in some embodiments to implement a plant management procedure, such as, but not limited to, the plant management process 10 illustrated in the flow chart of FIG. 1C. In this particular and non-limiting example, the Seqs management module 16s is configured and operable to generate valve control 15c data / signals and / or electrical power control 15e. In possible embodiments, the Seqs management module 16s is configured and operable to determine step durations for phases of the electrolysis process, and / or phase shifts between Set / reactors of each subsystem Sub i, Set j, and / or the number of steps for each phase, based at least in part on the conditions and / or rules and / or requirements set forth in FIGS. 3A-3E, and / or 4A-4C, and / or 5A-5C, and / or 6A-6H, and / or 10.

[0089] Optionally, but preferably in some embodiments, the Seqs management module 16s is also configured and operable to determine, e.g., based on control data / signals 18c from the power management module 16p, the number of active and / or inactive Sets / reactors, Set j, in each subsystem Sub i during operation of the plant 15. Thus, the Seqs management module 16s may also be configured and operable to generate control signals (not shown) for managing the timing and / or phase of activation of the Sets / reactors, Set j, during operation of the plant 15, e.g., as illustrated in Figures 7A and 7B, and / or for managing the timing and / or phase of deactivation of the Sets / reactors, Set j, during operation of the plant 15, e.g., as illustrated in Figures 8A-8C.

[0090] The control system 16 may also include a cleaning management module 16w configured and operable to implement various procedures for managing the selection of either the hot cleaning tank HW or the cold cleaning tank CW to supply the cleaning solution to the cleaning line Lw of the plant 15. The cleaning management module 16w may be configured and operable to implement various procedures for managing the selection of either the hot cleaning tank HW or the cold cleaning tank CW to supply the hot cleaning solution to the cleaning line Lw of the plant 15. 1 , H.W. 2 , ..., H.W. M and / or for supplying the cold cleaning solution to the cleaning line Lw of the plant 15. 1 , C.W. 2 , ..., C.W. M The device may be further configured and operable to implement various procedures for managing the selection of at least one of.

[0091] Optionally, but preferably in some embodiments, the plant 15 comprises various sensor devices 7 installed in the Set / reactors, Set j and / or solution tanks of the plant 15. The sensor devices 7 may be used to measure various parameters / conditions, such as solution temperature, pH, pressure conditions, flow rates, conductivity, and electrical voltages and / or currents of electrodes. Thus, the control system 16 may be configured and operable to receive the measurement data / signals 7s generated by the various sensor devices 7 and, based thereon, generate various control data / signals for operating the plant 15.

[0092] For example, in some embodiments, the cleaning management module 16w may include a high temperature cleaning tank HW 1 , H.W. 2 , ..., H.W. M at least one hot cleaning tank HW, which is used to supply hot cleaning solution to the cleaning line LW based on data / signals 7s indicating the temperature of the electrolyte solution in the 1 , H.W. 2 , ..., H.W. MThe control signal / data 15hi may be configured and operable to generate control data / signals 15hi used for the selection of

[0093] Similarly, the cleaning management module 16w controls the low-temperature cleaning tank CW 1 , C.W. 2 , ..., C.W. M at least one low-temperature cleaning tank CW, which is used to supply low-temperature cleaning solution to the cleaning line Lw of the plant 15 based on data / signals 7s indicating the temperature of the electrolyte solution in the 1 , C.W. 2 , ..., C.W. M The device may be configured and operable to generate control data / signals 15ci used for the selection of

[0094] In this manner, the control system may be adapted to effectively control and regulate the temperature of the hot and / or cold cleaning solutions by supplying cleaning solution from tanks that have reached the required operating temperature, while causing other cleaning solution tanks to adjust the temperature of the cleaning solutions stored therein to their required operating temperatures.

[0095] The plant 15 in some possible embodiments includes two subsystems Sub1 and Sub2, or multiple pairs of Sub1 and Sub2 subsystems. Figure 10 shows 20 phases of the plant 15, in a possible embodiment, with two subsystems Sub1 and Sub2, each with 9 Sets / reactors, Set j (1 ≤ j ≤ 9). Figure 10 further shows the use of cleaning solutions contained in the high temperature cleaning tank HW and / or the low temperature cleaning tank CW to convey the high temperature and low temperature solution cleaning sequences of the Sets / reactors according to the possible embodiments.

[0096] Such a hot and cold solution cleaning sequence of the Set / reactor may be performed as follows. Pushing the electrolyte solution in a Set / reactor, Set j, having a certain temperature level (i.e., high or low) by a cleaning solution having the same temperature level (i.e., high or low); Recycle the introduced cleaning solution with the same temperature level to clean the Set / reactor, Set j; Pushing a cleaning solution having the same temperature level by a cleaning solution having another temperature level (i.e., lower or higher); Recycle the introduced cleaning solution with other temperature levels to clean the Set / reactor, Set j; · Pushing the cleaning solution having another temperature level by the electrolyte solution having another temperature level (i.e., lower or higher).

[0097] A hot / cold solution cleaning sequence is illustrated by phases numbers 8-12 of Set9 of subsystem Sub2 (hereinafter Sub2 / Set9) enclosed by dashed box 25 in Figure 10. In this particular and non-limiting example, cleaning phases numbers 9-11 are conveyed which are used to replace the hot electrolyte solution of the oxygen producing O phase contained within Sub2 / Set9 with the cold electrolyte solution of the hydrogen producing H phase. This exemplary procedure is performed as follows: In phase number 8 ("LO-O"), the hot electrolyte solution of the oxygen production O phase contained in the Sub2 / Set9 Set / reactor is pushed out (e.g., back into the hot tank) by hot cleaning solution from at least one of the hot cleaning tanks HW; In phase number 9 ("LO"), a high temperature cleaning solution is circulated in Sub2 / Set9 to perform high temperature cleaning of the Set / reactor; In phase number 10 ("LH-LO"), the hot cleaning solution in the Sub2 / Set9 Set / reactor is pushed out (e.g., into at least one of the hot cleaning tanks HW) by the cold cleaning solution from at least one of the cold cleaning tanks CW; In phase number 11 ("LH"), low temperature cleaning solution is circulated in Sub2 / Set9 to perform low temperature cleaning of the Set / reactor; In phase number 12 ("H-LH"), the cold wash solution in the Sub2 / Set9 Set / reactor is pushed out (e.g., into at least one of the cold wash tanks CW) by cold electrolyte solution from the cold tanks to start a new hydrogen production H phase.

[0098] Similarly, a low temperature / high temperature solution cleaning sequence is illustrated by phase numbers 8-12 of Set6 of subsystem Sub1 (hereinafter Sub1 / Set6) enclosed by dashed box 26 in Figure 10. In this particular and non-limiting example, cleaning phase numbers 9-11 are conveyed which are used to replace the low temperature electrolyte solution of the hydrogen producing H phase contained within S2 / S9 with the high temperature electrolyte solution of the oxygen producing H phase. This exemplary procedure is performed as follows: In phase number 8 ("LH-H"), the low temperature electrolyte solution of the hydrogen production H phase contained in the Sub1 / Set6 Set / reactor is pushed out (e.g., back into the low temperature tank) by the low temperature cleaning solution from at least one of the low temperature cleaning tanks CW; In phase number 9 ("LH"), low temperature cleaning solution is circulated in Sub1 / Set6 to perform low temperature cleaning of the Set / reactor; In phase number 10 ("LO-LH"), the low temperature cleaning solution in the Sub1 / Set6 Set / reactor is pushed out (e.g., into at least one of the low temperature cleaning tanks CW) by the high temperature cleaning solution from at least one of the high temperature cleaning tanks HW; In phase number 11 ("LO"), a high temperature cleaning solution is circulated in Sub1 / Set6 to perform high temperature cleaning of the Set / reactor; In phase number 12 ("O-LO"), the hot cleaning solution in Sub1 / Set6 Set / reactor is pushed out (e.g., into at least one of the hot cleaning tanks HW) by hot electrolyte solution from the hot tank to start a new oxygen-producing O phase.

[0099] Thus, as illustrated in Fig. 10, in some embodiments, the control system 16 (e.g., cleaning module 16w) is configured such that whenever a low / high solution cleaning sequence (e.g., 25 in Fig. 10) is performed in one of the Sets / reactors, Set j, of subsystem Sub i, an opposite high / low solution cleaning sequence (e.g., 26 in Fig. 10) is performed in one of the Sets / reactors, Set j' (j' ≠ j is an integer) of subsystem Sub i' (i' ≠ i is an integer) of plant 15. It should be noted that the return piping and valves used to push the solution from the Set / reactor, Set j, back to the high or low tank and / or the high or low temperature cleaning tank HW or CW are not shown in Fig. 10 for simplicity, but they can be easily determined and implemented by one of ordinary skill in the art based on the disclosure of this application.

[0100] With reference to FIGS. 3A-3E, in some embodiments, the following rules / assumptions are followed to maintain a (perfect or quasi-) steady state: · Electrolyte push should be balanced (Figure 3A): This means that whenever a certain Set i (where i >= 1 is an integer) is in the LH push phase (shown in Figure 2C), a different Set j (where i ≠ j >= 1 is an integer) should be performing the HL push phase (shown in Figure 2I). In this way, the electrolyte level in the tank (and reactor / Set) is kept substantially constant. Similarly, for LO and OL phases, whenever some Set i is in the LO push phase (shown in Fig. 2G), a different Set j (i ≠ j) should be in the OL push phase (shown in Fig. 2E). The same number of Sets need to be in the H (i.e. active) phase (shown in Figure 2A) at a given time (Figure 3B), which means that the electrical power supply should be (quasi- or perfectly) constant. Set should be mostly in the H and O phases (shown in Figures 2A and 2F, respectively), which means that the durations in all of the other phases (T(H-), T(LH), T(L), T(OL), T(LO) and T(HL)) should be minimized (as the system is not producing anything in these states) and the durations of the H and O phases (T(H) and T(O)) should be maximized (Figure 3C).

[0101] Furthermore, the following is assumed: The duration of the L-phase (with tailings tank, as shown in Fig. 2D and Fig. 2H) should be at least two steps, i.e. whenever an L-phase is performed during a cycle, at least two L-phase steps are performed sequentially (to ensure that all gas (hydrogen or oxygen) is scrubbed from inside the Set / reactor). Thus, the total number of L-phase steps performed during a cycle is l T is,l T There should be ≧4 steps (Figure 3D). At least one H-phase step (shown in Fig. 2B and Fig. 2J) should occur before and after the H-phase (of Fig. 2A). Therefore, the number of H-phase steps in each cycle h (-) h (-) ≥ 2 steps (Figure 3E).

[0102] As a result, the conditions of Figures 4A-4E will be maintained during operation of the system. Sets should be kept synchronized with respect to other Sets, i.e., Set i is kept p steps (where p>0 is an integer) ahead of Set j (where i=j+1), which is p steps ahead of Set k (where k=i+1 is an integer), etc. (Figure 4A). Here, the phase difference p between Sets should always be kept constant (although it may be possible to construct sequences where the phase difference between Sets is not fixed). This makes it possible, for example, to "synchronize" the pushes for different Sets and keep the number of Sets in H-phase constant. If there are s Sets in the system and the phase difference between them is of p steps, then the total number of steps in each cycle (N) is, in some embodiments, a factor of p and a positive integer n s Multiplication by N, i.e., N=n s ×p (Figure 4B, where n s ≧1). If this condition is not met, after N steps, the Set of the system will not complete a full cycle. The number of H-phase steps in a cycle, h, is, in some embodiments, a function of p and a positive integer n a Multiplication with h = n a ×p (Figure 4C, where n a ≧1). If this condition is not met, the number of Sets in the H phase may not remain constant throughout the cycle. The Sets in the H phase are referred to herein as the active Set, and in some embodiments, the system is configured to monitor the number of active Sets during each cycle and ensure that the number remains constant. · The OL and LO phases (shown in Fig. 2E and Fig. 2G, respectively) always precede and follow the O phase. According to the above rules (Fig. 3A-3E), each OL phase in Set i needs to be matched with a respective LO phase in another Set, Set j (i ≠ j). To meet this requirement, the "distance" between the OL and LO phases is the sum of the phase difference p and another positive integer n o (where n o ≥ 1). Since the O phase is sandwiched between the OL and LO phases (i.e., the resulting sequence is OL, O, O, ..., O, LO), this requires that the number of steps in the O phase, o, must satisfy the following condition: o+1=n o ×p, where n o ≧1 means that it is an integer. The LH and HL phases (shown in Figures 2C and 2I, respectively) need to be synchronized as well. The HL and LH phases bracket the sequence of phases L, OL, O, LO and L. Thus, we obtain the following sequence of phases: LH, L, L, ..., L, OL, O, ..., O, LO, L, L, ..., L, HL. During the O phase, n o Since there are 1×p−1 steps, the distance between the LH and HL phases is, in some embodiments, n o ×p-1+l T +3. To synchronize the LH and HL phases, this formula is expressed as the phase difference p and a positive integer n L It should be multiplied by n o ×p+l T +2=n L ×p or l T =p×(n L -n o )-2.

[0103] The above rules, assumptions and conditions result in the following relationships: N=n s ×p h=n a ×p o=n o ×p-1 l T =p×(n L -n o )-2 where N is the total number of steps in the electrolysis cycle, p is the number of steps in the phase difference between two Sets i and j (i ≠ j), and n s represents the total number of steps in each electrolysis cycle, N, in terms of the number of phase difference (p) durations, h is the total number of steps in the H phase, and n a represents the total number of steps in the H phase in terms of the number of phase difference (p) durations, o is the total number of steps in the O phase, and n o represents the number of phase difference (p) durations during the O phase + 1 step, and l T is the total number of steps in all L phases in the cycle, and n L represents the duration between the LH and HL phases as a number of phase difference (p) durations.

[0104] Thus, the total number of steps N in an electrolysis cycle in a possible embodiment is the sum of the number of steps in the H phase (i.e., h) and the number of steps in the L phase (i.e., l T ), the total number of steps during the O-phase (i.e., o), and the total number of steps during the H-phase (i.e., h (-) ), and the total number of steps in the push phases LH, OL, LO and HL (each of which is a single step in duration, i.e., a total of four push steps are required). Thus, the total number of steps in the electrolysis cycle, N, is N=l T +h+o+h (-) +4 N = [p × (n L -n o )-2]+[n a ×p]+[n o×p-1]+h (-) +4 N = p × (n L +n a )+h (-) +1 where l T ≧4 and h (-) ≧2. From this result, the total number of steps in the H-phase, h (-) teeth, h (-) =Np×(n L +n a )-1=[n s ×p]-p×(n L +n a )-1=p×(n s -n a -n L )-1 It can be expressed as:

[0105] h (-) ≧2, l T ≧4 and o≧1, we obtain the following inequality (FIG. 5A): h (-) =p×(n s -n a -n L )-1≧2 : p×(n s -n a -n L )≧3 (1) l T =p×(n L -n o )-2≧4 : p×(n L -n o )≧6 (2) o=n o ×p-1≧1 : p×n o ≧2 (3)

[0106] Combining inequalities (1) with (2) and (2) with (3), we obtain the following inequalities (Figure 5B): p×(n s -n a -n o )≧9 (4) p×n L ≧8 (5)

[0107] Therefore, under all constraints, the formula (n s -n a -n o ) (FIG. 5C). Alternatively, some "waste" H and / or L phase steps may be performed beyond the minimum number required, which would result in a less than optimal Set operation.

[0108] In some embodiments, the above inequalities are used by the control system 16 to ensure efficient and substantially constant electrolysis production by multiple Sets (Set1, Set2, ..., Set i) of plants 15. Further analysis of these inequalities can be used to derive additional possible control rules / conditions, which are described below. As summarized in FIG. 6A, from inequality (2): p=1 : (n L -n o ) ≧ 6 steps p=2 : (n L -n o ) ≧ 3 steps Since 3≦p≦5 implies that 1≦(6 / p)≦2 (since only integers are involved), 3≦p≦5 : (n L -n o ) ≧ 2 steps Since p≧6 gives 0≦(6 / p)≦1, p≧6 : (n L -n o ) ≧ 1 step become.

[0109] FIG. 6B summarizes the above control rules.

[0110] As summarized in FIG. 6B, the above rules and T =p×(n L -n o )-2, based on l T The value of can be minimized as follows: p=1 : min(l T)=4 steps p=2 : min(l T )=4 steps 3≦p≦5 : min(l T )=2×p-2 steps p≧6 : min(l T )=p-2 steps

[0111] As summarized in FIG. 6C, inequalities (1) and (n s -n a -n L ) ≧ 3 / p, p=1 : (n s -n a -n L ) ≧ 3 p=2 : (n s -n a -n L )≧2 p=3 : (n s -n a -n L ) ≧ 1 As summarized in FIG. 6D, (-) =p×(n s -n a -n L )-1 ≧ 2, so h (-) The minimum of is therefore p=1 : h (-) =2 steps p=2 : h (-) =3 p≧3 : h (-) =p-1 steps become.

[0112] As summarized in FIG. 6E, inequality (3) and o=n o ×p-1 ≧ 1, p=1 : n o =2 steps p≧2 : n o = 1 step become.

[0113] As summarized in FIG. 6F, inequality (4) and n s ≧9 / p+na +n o from, p=1, n o =2 and n a ≧1 : n s ≧9+n a +n o → n s =12 steps p=2, n o ,n a ≧1 : n s ≧5+n a +n o → n s =7 steps p=3, n o ,n a ≧1 : n s ≧3+n a +n o → n s =5 steps p=4, n o ,n a ≧1 : n s ≧3+n a +n o → n s =5 steps 5≦p≦8, 1 <p / 9<2 : n s ≧2+n a +n o → n s =4 steps p ≥ 9, 0 <p / 9<1 : n s ≧1+n a +n o → n s =3 steps become.

[0114] As summarized in FIG. 6G, inequality (4) further reads: p=1 : n s -n a -n o ≧9 steps p=2 : n s -n a -n o ≧5 steps p=3, 4 : n s -n a -n o ≧3 steps p=5~8 : n s -n a -n o ≧2 steps p≧9 : n s -n a -n o ≧1 step to provide.

[0115] As summarized in FIG. 6H, p, n s , n a and n o And l T ≧4 and h (-) The above results for minimization of ≧2 can be combined to derive the number of steps in each of the different phases, where for the H, N, and O phases, the number of steps is N=n s ×p h=n a ×p o=n o ×p-1 is given by:

[0116] To support solar power and remain efficient, in some embodiments, plant 16 initially begins operating with a reduced / minimum number of Sets (e.g., at the beginning of the day), increases the number of Sets to a defined maximum capacity, for example at noon, and toward the end of plant operation (e.g., at the end of the day), the number of Sets is again reduced to the reduced / minimum number of Sets before shutting down the plant in the most efficient manner to begin operation of plant 16 again the next day.

[0117] To add an active Set during operation, the plant / system should be in a state similar to that illustrated in FIG. 7A, where one of the Sets is in the LO phase (Set4 in this example), which occurs every 6-7 steps depending on the plant / system configuration. From this stage of the plant / system operation, a new Set can be started, e.g., a new Set5 is added in FIG. 7B. Thus, if there are n simultaneously operating Sets, Set1, Set2, ..., Set n, to start operation on the new Set n+1, a sequence of at least n-1 phases of the Set to be added should be found in one of the currently operating Sets in a similar position, so that the n Sets can continue their operation normally.

[0118] To deactivate a Set, the plant / system must be in a state similar to that illustrated in FIG. 8A, where one of the Sets is in the LO phase (Set5 in this example), and such a state occurs every 6-7 states, depending on the plant / system configuration. The deactivated Set (Set5 in this example) should have two more steps, L and HL, before it is deactivated, as illustrated in FIG. 8B. The operation of the plant / system can then continue normally with a reduced number of Sets, as illustrated in FIG. 8C. Thus, in some embodiments, a Set is deactivated after performing a cleaning phase after one of the production phases (i.e., H or O). In possible embodiments, the duration of the electrolysis process phases is dynamically set before and / or during plant operation, as described below. The following description makes use of the following provisions: τ c : Electrolysis cycle duration (e.g., as shown in Figures 2A-2J), N s : the number of sets Set j in subsystem Sub i, N a: the number of active sets in subsystem Sub i, τ h : Length / duration of hydrogen production H phase, τ lo :LO and OL phase push length / duration, τ lh :LH and HL phase push length / duration, τ o Length / duration of the oxygen-producing O phase, τ l : the average length / duration of the residue / cleaning L phase, and τ h :Average length / duration of H-phase.

[0119] Therefore, the "phase" φ between two Sets is TIFF2025510509000003.tif11170, from which the following formula is derived: τ c =φN s (6)

[0120] For the same reason, as in the fixed-length steps analysis, the length / duration of the hydrogen-producing H phase is TIFF2025510509000004.tif12170, from which the following formula is derived: τ h =φN a (7)

[0121] Similarly, the duration between the LO push (during which the oxygen-producing O phase is carried out) and the LH push is a function of φ and a positive integer N o This may be required to be equivalent to multiplication with τ o +τ lo =φN o (8) results.

[0122] Similarly, the duration between the LH and HL pushes is also required to be a multiplication of φ and a positive integer k, which can be expressed as This results in TIFF2025510509000005.tif9170, where TIFF2025510509000006.tif8170 is the length / duration of the residue / cleaning steps for i ∈ 1, 2, which in principle do not have the same duration. However, TIFF2025510509000007.tif9170 is τ lh +τ o +2τ lo +2τ l =φk (10) and by substituting equation (8) into equation (10), the following relationship is obtained: τ lh +φN o +τ lo +2τ l =φk, This is a relationship τ lh +τ lo +2τ l =φ(kN o ) (11) to provide.

[0123] Since it is desired to minimize the duration of the push (LH, LO, etc.) and residue / clean (L) phases, and since their durations are non-zero, the left hand side of equation (11) becomes o = 1, so this is τ lh +τ lo +2τ l =φ (12) to provide.

[0124] Summing up the entire electrolysis cycle / sequence gives the formula 2τ h- +2τ lh +2τ l +2τ lo +τ h+τ o = τ c (13) yields (τ l As explained above with respect to τ, the two H-phases before and after the hydrogen-producing H-phase can be of different durations, h- is defined as the average of the mean durations of these H-phases).

[0125] Substituting equations (6), (7), and (8) into (13) gives 2τ h- +2τ lh +2τ l +τ lo =φ(N s -N a -N o ) (14) Substituting Eq. (12) gives 2τ h- +τ lh =φ(N s -N a -N o -1) (15) results.

[0126] For x∈{h-, lh, l, lo}, τ × >0, and since φ>0, N s -N a -N o -1≧1 (16) Therefore, N s ≧N a +N o +2 (17) become.

[0127] From equation (14), we obtain the following: 2τ h- +2τ lh +2τ l +τ lo ≧2φ (18)

[0128] Therefore, we have the following system of independent (in)equations, τc =φN s (6) τ h =φN a (7) τ o +τ lo =φN o (8) τ lh +τ lo +2τ l =φ (12) N s ≧N a +N o +2 (17) 2τ h- +2τ lh +2τ l +τ lo ≧2φ (18) Here, there are 6 equations and 11 unknowns (τ c , τ h , τ o , τ l , τ h- , τ lh , τ lo ,φ,N s , N a , N o ) φ, N s , N a , τ lo and τ lh If is fixed (in other possible embodiments, other / different sets of unknowns may be chosen to be fixed), this provides: τ c =φN s (19a) τ h =φN a (19b) τ o =φN o -τ lo (19c) 2τ l = τ lh +τ lo -φ (19d) N o ≦N s -N a -2 (19e) 2τ h- +2τ l ≧2φ-2τlh -τ lo (19f) In addition, the following is obtained: (14g) l , τ h- , τ o >0

[0129] Solving this system will yield a valid sequence. However, the optimal sequence will reduce the time the system is not in hydrogen or oxygen production. If equation (19e) is multiplied by φ, the following equation is obtained: φN o ≦φN s -φN a -2φ (20)

[0130] That is, (by substituting equations (6), (7), and (8)), τ c -τ h -τ o ≧2φ-τ lo (twenty one) become.

[0131] Since it is desired to minimize the left hand side of equation (21), this is achieved when the inequality sign "≧" is replaced with an equality sign "=", i.e. τ c -τ h -τ o =2φ-τ lo (21a) This means that equation (19) is N o =N s -N a -φ (22) This means that

[0132] Similarly, from equation (18), 2τ h- +2τ lh +2τ l +τ lo ≧2φ (18) become.

[0133] To minimize the left hand side, this means that the inequality sign >= is replaced with the equality sign "=". 2τ h- +2τ lh +2τ l +τ lo =2φ (23) This is the following system of equations: τ c =φN s (24a) τ h =φN a (24b) τ o =φN o -τ lo (24c) 2τ l = τ lh +τ lo -φ (24d) N o =N s -N a -2 (24e) 2τ h- +2τ l =2φ-2τ lh -τ lo (24f) is solved, which provides τ c =φN s (25a) τ h =φN a (25b) τ o =φN o -τ lo (25c) 2τ l =(τ lh +τ lo -φ) (25d) N o =N s -N a -2 (25e) 2τ h- =3φ-3τ lh -τ lo -2 (25f) results.

[0134] As explained above, τl and τ h- is the average of two phases each. However, since these phases perform the same "action", there is little point in making them different.

[0135] Optionally, but preferably in some embodiments, various parameters of the electrolysis process, and that of the phases of the electrolysis process, are determined as follows.

[0136] τ h (length / duration of hydrogen production phase H), τ lo and τ lh (push length / duration), and (integer) N s Given a number of Sets in the system >= 3, an integer number of active Sets is chosen under the following conditions: TIFF2025510509000008.tif11170N a <τ h / τ lh Since the following is true, (19b) φ=τ h / N a The length of the cycle can be expressed as: (19a) τ c =φN s

[0137] Oxygen production phase length N o (Integer) is (19e) 1≦N o ≦N s -N a -2 (above, N a is at least N o = 1 was chosen to solve this inequality).

[0138] Furthermore, the following formula: To meet the TIFF2025510509000009.tif12170, the length of the oxygen production phase is (19c) τo =φN o -τ lo (N o Due to the way in which was selected, τ o >0 is obtained).

[0139] The sum of the two residue / wash phases (which in principle could be different) is therefore: (19d) 2τ l = τ lh +τ lo -φ (N a Due to the way in which was selected, τ l is guaranteed to be >0).

[0140] Here, τ l is the average length of the two residue / cleaning phases (there are two residue "phases" in the sequence. 2τ l is the sum of both. You never care about the length of one of them, just the sum.) Finally, you need to determine the H-phase (again, there are two such phases in the sequence), so (19f) 2τ h- ≧2φ-2τ lh -τ lo -2τ l (N a Due to the way in which was selected, τ h- is guaranteed to be positive. In detail, 2φ-2τ lh -τ lo -2τ l =2φ-2τ lh -τ lo -(τ lh +τ lo -φ)=3φ-3τ lh =3(τ h / N a -τ lh )>0 τ h / N a -τ lh >τ h / (τ h / τlh )-τ lh = τ lh -τ lh =0 (It is.)

[0141] Throughout this disclosure, when a process or method is shown or described, it should be understood that the steps / acts of the method may be performed in any order and / or simultaneously, and / or with other steps / acts not shown / described herein, unless it is clear from the context that a step is dependent on another step being performed first. In possible embodiments, not all of the steps / acts shown / described are required to perform the method.

[0142] As described above and shown in the associated figures, the present application provides a control scheme for an electrolysis system / process and related methods. Although specific embodiments of the disclosed subject matter have been described, it will be understood that the disclosed subject matter is not limited thereto, as modifications may be made by those skilled in the art, especially in light of the teachings above. As will be appreciated by those skilled in the art, the disclosed subject matter may be carried out in a wide variety of ways, employing two or more techniques from those described above, all without exceeding the scope of the claims.

Claims

1. a plurality of reactors each comprising an electrolysis electrode and configured to perform a sequence of phases of an electrolysis process, the sequence of phases of the electrolysis process being phase-shifted relative to a sequence of phases of the electrolysis process performed by at least another one of the plurality of reactors; one or more power sources for driving the electrolysis process performed by the plurality of reactors; monitoring a change in the power capacity of at least one of the one or more power sources; and based thereon, (i) activating or deactivating one or more of the electrolysis processes performed by the plurality of reactors; (ii) adjusting the duration of at least one of the phases of the electrolysis process; (iii) adjusting the power supplied from the one or more power sources to at least one of the plurality of reactors; and / or (iv) adjusting, removing or introducing at least one phase of said electrolysis process. a control system configured to implement at least one of An electrolysis system comprising:

2. 10. The system of claim 1, configured to perform the electrolysis process in each reactor during successively repeated cycles, each cycle comprising at least one hydrogen production phase (H) from a low temperature electrolyte solution, followed by a low temperature electrolyte push-out phase (L-H) in which the low temperature electrolyte is replaced with a cleaning solution, followed by at least one cleaning phase (L) in which the electrolysis electrodes of the reactor are cleaned, followed by a cleaning solution push-out phase (O-L) in which the cleaning solution is replaced with a high temperature electrolyte solution, followed by at least one oxygen production phase (O) from the high temperature electrolyte, followed by a high temperature electrolyte push-out phase (L-O) in which the high temperature electrolyte solution is replaced with a cleaning solution, followed by at least one cleaning phase (L) in which the electrolysis electrodes of the reactor are cleaned, followed by a cleaning solution push-out phase (H-L) in which the cleaning solution is replaced with a low temperature electrolyte solution, followed by at least one hydrogen production inhibition phase (H-).

3. 3. The system of claim 2, further comprising at least one hydrogen production inhibition phase (H-) between the at least one hydrogen production (H) phase from the low temperature electrolyte solution and the low temperature electrolyte push-out phase (L-H) and / or after the cleaning solution push-out phase (H-L) and before a new hydrogen production (H) phase of a new cycle is initiated.

4. The duration of one or more of said phases and / or the entire electrolysis process is defined as an electrolysis cycle duration τ ｃ , and / or the number N of reactors in the system ｓ , and / or the number N of active reactors in the system ａ , and / or the length / duration τ of the hydrogen production (H) phase ｈ , and / or the length / duration τ of said (LO) and (OL) pushes ｌｏ , and / or the length / duration τ of said (LH) and (HL) pushes ｌｈ , and / or the length / duration τ of the oxygen-producing (O) phase ｏ , and / or the average length / duration of the residue / cleaning (L) phase τ ｌ , and / or the average length / duration of said (H-) phase τ ｈ－ configured to determine based on at least one of and / or configured to determine the duration of one or more of the phases and / or the entire electrolysis process based on the length / duration of the (L-H) and (H-L) pushes τ lh , the length / duration of the (L-O) and (O-L) pushes τ lo , the length / duration of the hydrogen production (H) phase τ h , the number of reactors in the system N s , and / or the number of active reactors in the system N a ; and / or the duration of one or more of the phases and / or the entire electrolysis process based on the length / duration τ h of the hydrogen production (H) phase, the length / duration τ o of the oxygen production (O) phase, the average length / duration τ l of the residue / cleaning (L) phase, the length / duration τ lh of the (L-H) and (H-L) pushes.

5. 3. The system of claim 2, wherein the duration of each of the hydrogen production (H) phase, the hydrogen production inhibition phase (H−), the cleaning phase (L), and the oxygen production (O) phase is substantially equal to a step duration multiplied by a natural number, and the step duration is the duration of at least one of the push-out phases.

6. the total duration of the cleaning phase (L) in each cycle is configured to be at least substantially equal to the step duration multiplied by 4 when the number of phase shifts between the reactors is 1, 2 or 3, the step duration multiplied by 6 when the number of phase shifts between the reactors is 4, and / or the step duration multiplied by 10 when the number of phase shifts between the reactors is 5, and / or the duration of the total phase shift minus the duration of two phases when the number of phase shifts between the reactors is greater than 5; and / or the total duration of the hydrogen production inhibition phase (H-) during each cycle is configured to be at least substantially equal to the step duration multiplied by 2 when the number of phase shifts between the reactors is 1, and / or the step duration multiplied by 5 when the number of phase shifts between the reactors is 2, and / or the step duration multiplied by 2 when the number of phase shifts between the reactors is 3, and / or the step duration multiplied by 3 when the number of phase shifts between the reactors is 4, and / or the step duration multiplied by 4 when the number of phase shifts between the reactors is 5 phases, and / or the duration of the total phase shifts between the reactors minus the duration of one phase when the number of phase shifts between the reactors is greater than 5, and / or the total duration of the cycle is configured to be substantially equal to at least the step duration multiplied by 12 and the number of phase shifts between the reactors when the number of phase shifts between the reactors is one, and / or the step duration multiplied by 7 and the number of phase shifts between the reactors when the number of phase shifts between the reactors is two, and / or the step duration multiplied by 5 and the number of phase shifts between the reactors when the number of phase shifts between the reactors is three, and / or the step duration multiplied by 4 and the number of phase shifts between the reactors when the number of phase shifts between the reactors is between four and eight inclusive, and / or the step duration multiplied by 3 and the number of phase shifts between the reactors when the number of phase shifts between the reactors is greater than eight. and / or the total duration of the oxygen-producing (O) phase(s) during each cycle is configured to be greater than the step duration multiplied by 2 and the number of phase shifts between the reactors minus the duration of one phase when the number of phase shifts between the reactors is one, and / or greater than the step duration multiplied by the number of phase shifts between the reactors minus the duration of one phase when the number of phase shifts between the reactors is greater than one. and / or the total number of step durations during the low temperature electrolyte push-out phase (L-H) minus the total number of step durations during the low temperature electrolyte push-out phase (L-H) from the division of the difference between the total number of step durations in the cycle and the total number of step durations during the hydrogen production (H) phase by the number of inter-reactor phase shifts is substantially equal to at least 9 when the number of inter-reactor phase shifts is 1, and / or 5 when the number of inter-reactor phase shifts is 2, and / or 3 when the number of inter-reactor phase shifts is 3 or 4, and / or 2 when the number of inter-reactor phase shifts is between 5 and 8 inclusive, and / or 1 when the number of inter-reactor phase shifts is greater than 8.

7. The system of claim 1 , wherein at least one of the power sources or all of the power sources is a renewable power source.

8. 8. The system of claim 7, wherein the control system is configured to receive and process sensory data / signals indicative of changes in environmental conditions and, based thereon, predict potential changes in the power capacity of the renewable power source.

9. 3. The system of claim 2, comprising: a reservoir containing the high temperature electrolyte solution; a reservoir containing the low temperature electrolyte solution; a reservoir containing the cleaning solution; and equipment for controllably flowing the solutions between the reservoirs and each of the plurality of reactors, wherein the control system is configured to flow solution from the reservoir to each of the plurality of reactors during each phase of the electrolysis process performed therein.

10. the control system is configured to apply an electric voltage across the electrolysis electrodes of each of the plurality of reactors only when performing a hydrogen production (H) phase of the electrolysis process, and to circulate the cold electrolyte solution between the cold electrolyte solution reservoir and the reactor performing the hydrogen production (H) phase of the electrolysis process. and / or the control system is configured to push the cold electrolyte solution back into the cold electrolyte solution reservoir by causing the cleaning solution to flow from the cleaning solution reservoir into the cold electrolyte solution reservoir during the cold electrolyte push-out phase (LH), and / or the control system is configured to circulate the low-temperature electrolyte solution between the low-temperature electrolyte solution reservoir and the reactor during the hydrogen production inhibiting phase (H-) without applying the electric voltage to the electrolysis electrodes thereof, and / or the control system is configured to circulate the cleaning solution between the cleaning solution reservoir and the reactor during the cleaning phase (L) to clean gas production residues from the electrolysis electrodes of the reactor, and / or the control system is configured to push the cleaning solution from the reactor back into the cleaning solution reservoir by flowing the hot electrolyte solution from the hot electrolyte solution reservoir into the reactor during the cleaning solution push-out phase (OL), and / or the control system is configured to circulate the high temperature electrolyte solution between the high temperature electrolyte solution reservoir and each of the plurality of reactors during the oxygen production phase (O) of the electrolysis process. and / or the control system is configured to push the hot electrolyte solution back into the hot electrolyte solution reservoir by flowing the cleaning solution from the cleaning solution reservoir into the hot electrolyte solution reservoir during the hot electrolyte push-out phase (LO), and / or the control system is configured to push the cleaning solution from the reactor back into the cleaning solution reservoir by flowing the cold electrolyte solution from the cold electrolyte solution reservoir into the reactor during the cleaning solution push-out phase (H-L).

11. 11. The system of claim 10, configured to maintain the cleaning solution in the cleaning solution reservoir at a temperature substantially less than a temperature of the hot electrolyte solution and substantially greater than a temperature of the cold electrolyte solution.

12. 11. The system of claim 10, wherein the cleaning solution reservoir comprises one or more cold cleaning solution sub-reservoirs for cold cleaning solution maintained at temperature(s) greater than a temperature of the cold electrolyte solution, and one or more hot cleaning solution sub-reservoirs for hot cleaning solution maintained at temperature(s) less than a temperature of the hot electrolyte solution and greater than the temperature(s) of the cold cleaning solution, and wherein the control system is configured to use the cold cleaning solution from the one or more cold cleaning solution sub-reservoirs during the hot electrolyte push-out phase (L-O) and during the at least one cleaning phase (L) thereafter, and to use the hot cleaning solution from the one or more hot cleaning solution sub-reservoirs during the cold electrolyte push-out phase (L-H) and during the at least one cleaning phase (L) thereafter.

13. 13. An electrolysis plant comprising two or more of the electrolysis systems of any one of claims 1 to 12 utilizing a single high temperature electrolyte reservoir, a single low temperature electrolyte reservoir, and one or more cleaning solution reservoirs, wherein a control system is configured to effect a (L-H), (L), and (O-L) phase sequence in one of the two or more electrolysis systems, and a (L-O), (L), and (H-L) phase sequence in at least another of the two or more electrolysis systems.

14. 1. A method of electrolysis comprising: performing an electrolysis process having a sequence of phases in a plurality of reactors, each reactor comprising electrolysis electrodes and performing the electrolysis process with a phase shift relative to at least another one of the plurality of reactors; monitoring changes in power capacity of one or more power sources used by the plurality of reactors to perform the electrolysis process; and based thereon, at least one of activating or deactivating one or more of the electrolysis processes performed by the plurality of reactors, adjusting a duration of at least one of the phases of the electrolysis process, adjusting power supplied from the one or more power sources to at least one of the plurality of reactors, and / or adjusting, removing, or introducing at least one phase of the electrolysis process.

15. 15. The method of claim 14, comprising conducting the electrolysis process in the reactor in successively repeated cycles, each cycle comprising at least one hydrogen production phase (H) from a low temperature electrolyte solution, followed by a low temperature electrolyte push-out phase (L-H) in which the low temperature electrolyte is replaced with a cleaning solution, followed by at least one cleaning phase (L) in which the electrolysis electrodes of the reactor are cleaned, followed by a cleaning solution push-out phase (O-L) in which the cleaning solution is replaced with a high temperature electrolyte solution, followed by at least one oxygen production phase (O) from the high temperature electrolyte, followed by a high temperature electrolyte push-out phase (L-O) in which the high temperature electrolyte solution is replaced with a cleaning solution, followed by at least one cleaning phase (L) in which the electrolysis electrodes of the reactor are cleaned, followed by a cleaning solution push-out phase (H-L) in which the cleaning solution is replaced with a low temperature electrolyte solution.

16. 16. The method of claim 15, comprising at least one hydrogen production inhibition phase (H-) between the at least one hydrogen production (H) phase from the low temperature electrolyte solution and the low temperature electrolyte push-out phase (L-H) and / or after the cleaning solution push-out phase (H-L) and before a new hydrogen production (H) phase of a new cycle is initiated.

17. 16. The method of claim 15, comprising setting the duration of each of the hydrogen production (H) phase, the hydrogen production inhibition phase (H-), the cleaning phase (L), and the oxygen production (O) phase to be substantially equal to a step duration multiplied by a natural number, wherein the step duration is the duration of at least one of the push-out phases.

18. 16. The method of claim 15, comprising adjusting the electrical current supplied to at least one of the plurality of reactors when it is determined that a reduction in the power capacity of the power source may cause short-term fluctuations in power supply.

19. 20. The method of claim 18, further comprising adjusting a duration of at least one of the phases of the electrolysis process when it is determined that a reduction in the power capacity of the power source is likely to cause longer term fluctuations in the power supply.

20. 20. The method of claim 19, further comprising adjusting a duration of at least one of the phases and / or a sequence of phases of the electrolysis process when it is determined that reducing the power capacity of the power source may substantially reduce the efficiency of the electrolysis process.

Images