EP4486938A2

EP4486938A2 - Method and device for producing hydrogen from water

Info

Publication number: EP4486938A2
Application number: EP23710802.2A
Authority: EP
Inventors: Valeriy Anatol'evic GUZYEYEV; Jan PARLEVLIET
Original assignee: Water Energy Patent BV
Current assignee: Nashel BV
Priority date: 2022-03-03
Filing date: 2023-03-02
Publication date: 2025-01-08
Also published as: WO2023167585A2; NL2031152B1; WO2023167585A3

Abstract

In the field of producing hydrogen from water, a method is provided that comprises providing a device (100) comprising an electric circuit (30) including an electric energy source (31) and at least two electrodes, and further comprising a cell (11, 12) having an internal space (13) in which the water is present and in which the at least two electrodes are arranged at a distance relative to each other, and continuously setting an extent to which energy is transmitted from the electric energy source (31) to the electrodes in dependence on at least one of an actual value of at least one parameter related to the condition of the water in the cell (11, 12) and an actual time derivative of such at least one parameter. By taking into account the actual and natural behavior/response of the water, the hydrogen production process can be highly energy-efficient.

Description

Method and device for producing hydrogen from water

FIELD OF THE INVENTION

In the first place, the invention relates to a method for producing hydrogen from water, comprising: providing a device comprising an electric circuit including an electric energy source and at least two electrodes, and further comprising a cell having an internal space in which the water is present and in which the at least two electrodes are arranged at a distance relative to each other.

In the second place, the invention relates to a device designed to produce hydrogen from water, comprising an electric circuit including an electric energy source and at least two electrodes, and further comprising a cell having an internal space configured to contain the water, in which the at least two electrodes are arranged at a distance relative to each other.

In the third place, the invention relates to a device designed to generate at least one of heat and electric energy from hydrogen, comprising a device designed to produce hydrogen from water as mentioned here before.

In the fourth place, the invention relates to an entity comprising a device designed to generate at least one of heat and electric energy from hydrogen as mentioned here before.

BACKGROUND OF THE INVENTION

In the search for ways to reduce the use of fossil fuels, or to even terminate the use of fossil fuels, using hydrogen appears to be one of the most promising options. In view of the fact that hydrogen is a gas that does not occur naturally on Earth in large quantities, production methods are necessary when it is desired to obtain hydrogen. Known production methods which do not require an input of a fossil fuel such as methane or coal as basic material include biomass gasification and electrolysis of water. In electrolysis, electricity is run through water to separate the hydrogen and oxygen atoms.

It is a well-known fact that a water molecule is made up of two hydrogen atoms and one atom of oxygen. This is the reason why water is a potential source of hydrogen. However, until now, no one has succeeded in mass production of hydrogen from water with very high energy efficiency. Electrolysis of water, as mentioned here before, requires so much electrical energy compared to the energy content of the hydrogen produced that this hydrogen producing technique is hardly used in practice.

SUMMARY OF THE INVENTION

It is an objective of the invention to provide a way of producing hydrogen from water that involves very high energy efficiency, i.e. that requires much less input of energy than known ways for obtaining the same amount of hydrogen. In view thereof, the invention provides a method for producing hydrogen from water, comprising: providing a device comprising an electric circuit including an electric energy source and at least two electrodes, and further comprising a cell having an internal space in which the water is present and in which the at least two electrodes are arranged at a distance relative to each other, and continuously setting an extent to which energy is transmitted from the electric energy source to the electrodes in dependence on at least one of an actual value of at least one parameter related to the condition of the water in the cell and an actual time derivative of such at least one parameter.

Also, the method provides a device designed to produce hydrogen from water, comprising: an electric circuit including an electric energy source and at least two electrodes, a cell having an internal space configured to contain the water, in which the at least two electrodes are arranged at a distance relative to each other, a detecting arrangement configured to detect an actual value of at least one parameter related to the condition of the water in the cell, and a controller arrangement configured to receive and process input from the detecting arrangement and to continuously set an extent to which energy is transmitted from the electric energy source to the electrodes in dependence on the input from the detecting arrangement.

The invention is based on the insight that when an action of supplying electric energy to the electrodes is initiated, a process is initiated as a result of which the cell is charged as if the cell is a capacitor. At a certain point, the extent to which the cell is charged is such that the water reacts. In the process, a plasma field including micro cavities is created, and splitting of the water molecules takes place as the tiny bubbles implode, through a process involving formation of ions in the water and reactions of these ions involving electrons, wherein the following formula are applicable:

1) 4H₂O ^ 2H₃O⁺ + 2OH-

2) 4H₃O⁺ + 4e 2H₂ + 4H₂O and 4OH’ 4e + O₂ + 2H₂O

As a result, hydrogen and oxygen are generated. Putting the invention to practice involves relying on at least one of an actual value of at least one parameter related to the condition of the water in the cell and an actual time derivative of such at least one parameter. In this way, a possibility to act in accordance with the natural behavior of the water in the cell is created, and this offers an opportunity to adapt the supply of energy such that the energy potential of water is used in an optimal fashion and only a minimum of energy is taken from the electric energy source.

Advantageously, putting the invention to practice involves continuously monitoring the actual value of the at least one parameter related to the condition of the water in the cell. According to a practical option, a controller value of the extent to which energy is transmitted from the electric energy source to the electrodes is determined by continuously comparing the at least one of the actual value of the at least one parameter related to the condition of the water in the cell and the actual time derivative of such at least one parameter to a respective reference, and the extent to which energy is transmitted from the electric energy source to the electrodes is set in accordance with the controller value. In order to account for differences of batches of water in the cell, it may be beneficial to set the reference in dependence on a value of the at least one parameter related to the condition of the water in the cell for an initial condition of the water in the cell.

According to a practical option, setting the extent to which energy is transmitted from the electric energy source to the electrodes involves setting one of two values of the extent, one of the two values being significantly lower than the other of the two values. The lowest value may be zero, and it is possible that setting the extent to which energy is transmitted from the electric energy source to the electrodes involves setting an interrupted state or a closed state of the electric circuit, for example. Thus, in such a case, varying the extent to which energy is transmitted from the electric energy source to the electrodes between a lowest extent and a highest extent is realized by varying the extent between zero and a value related to the closed state of the circuit, i.e. a value dependent on the characteristics of the electric circuit including the electric energy source and the at least two electrodes.

A practical example of the at least one parameter related to the condition of the water in the cell is the electrical resistance of the water between the at least two electrodes. In the context of the invention, it has been found that at the moment of the transition of the water in the cell from a normal condition to a plasma condition, the electric resistance of the water between the at least two electrodes is significantly lower than in the normal condition of the water. In view thereof, it may be practical to choose a first reference value as a criterion for setting the extent to which energy is transmitted from the electric energy source to the electrodes at a relatively high value so as to be higher than a second reference value as a criterion for setting the extent to which energy is transmitted from the electric energy source to the electrodes at a relatively low value. This is then a way of achieving that as long as the electric resistance of the water is higher than the second reference value, the extent to which energy is transmitted from the electric energy source to the electrodes is set at the relatively high value, which causes the cell to get electrically charged, and that as soon as the electric resistance drops below the second reference value, which happens when the plasma field is formed and the cell discharges, the extent to which energy is transmitted from the electric energy source to the electrodes is set at the relatively low value, which relatively low value may be zero as explained earlier. In the terms of the example of interrupting and closing the electric circuit, it may be so that the closed state of the electric circuit is set when the electrical resistance of the water is at a first reference value, and that the interrupted state of the electric circuit is set when the electrical resistance of the water has dropped from the first reference value to below a second reference value that is lower than the first reference value. In any case, it may be practical to determine at least the first reference value in dependence on a value of the electrical resistance of the water in an initial condition in the cell. The invention covers any possible way of detecting the actual value of the electrical resistance of the water. For example, the actual value of the electrical resistance of the water may be measured by means of a Wheatstone bridge.

According to another feasible example, the condition of the water is continuously monitored in an acoustic fashion, i.e. by using a microphone or the like. The basic assumption for this technique is that the level of noise from the water increases drastically at the transition from the normal condition to the plasma condition and decreases back to a zero level at the end of the plasma condition.

In the present text, a parameter related to the condition of the water in the cell can be understood as a parameter of which the value follows from the condition of the water in the cell, in other words, a parameter of which the value is determined by the condition of the water in the cell. Practical examples of the value of the parameter are quantifications of features of the water as such and include the above-mentioned value of the electrical resistance of the water between the at least two electrodes and the above-mentioned level of the noise from the water.

The method according to the invention further covers the following options:

- receiving hydrogen and oxygen from the cell, separating the hydrogen and the oxygen, and discharging the hydrogen and the oxygen to separate discharge positions, and

- using filtered tap water as the water in the cell, wherein it may particularly be so that metal particles and probably also lime particles have been removed from the water.

In the context of the invention, it has been demonstrated that the combustion energy content of hydrogen produced by applying the method according to the invention exceeds 336 kJ. This demonstration is based on direct heating of 1 kg tap water from 20°C to 100°C by combustion of the hydrogen, using the oxygen produced in the process. The external electrical energy applied for the purpose of producing the hydrogen and the oxygen from water is 60 kJ. It follows from these calculations that the Coefficient of Performance (COP) is higher than 5.

In conformity with what is mentioned in the foregoing, in terms of a device, the invention provides a device designed to produce hydrogen from water, comprising the electric circuit including the electric energy source and the at least two electrodes, and the cell having the internal space configured to contain the water, in which the at least two electrodes are arranged at a distance relative to each other, and further comprising a detecting arrangement configured to detect the actual value of at least one parameter related to the condition of the water in the cell, and a controller arrangement configured to receive and process input from the detecting arrangement and to continuously set the extent to which energy is transmitted from the electric energy source to the electrodes in dependence on the input from the detecting arrangement.

Further, in conformity with what is mentioned in the foregoing, in terms of the device, it may be so that the detecting arrangement is configured to continuously monitor the actual value of the at least one parameter related to the condition of the water in the cell, and that the controller arrangement is configured to determine a controller value of the extent to which energy is transmitted from the electric energy source to the electrodes by continuously comparing at least one of the actual value of the at least one parameter related to the condition of the water in the cell and an actual time derivative of such at least one parameter to a respective reference, and to set the extent to which energy is transmitted from the electric energy source to the electrodes in accordance with the controller value. It is the controller arrangement that may be configured to set the reference in dependence on input from the detecting arrangement related to an initial condition of the water, and it is also the controller arrangement that may be configured to set the extent to which energy is transmitted from the electric energy source to the electrodes through setting an interrupted state or a closed state of the electric circuit, or, more in general, to set the extent to which energy is transmitted from the electric energy source to the electrodes at an appropriate one of two values of the extent, one of the two values being significantly lower than the other of the two values.

In the case that the at least one parameter related to the condition of the water in the cell comprises the electrical resistance of the water between the at least two electrodes, it is practical if the detecting arrangement comprises at least one sensor configured to detect the electrical resistance of the water between the at least two electrodes. In conformity with wat is suggested earlier, a practical example of the at least one sensor is a sensor comprising a Wheatstone bridge.

Practical aspects of the device covered by the invention include the following:

- at least one of the at least two electrodes comprises a plate that is made from titanium Grade 1 , titanium Grade 2 or titanium Grade 5 and that is provided with a mixed metal coating,

- at least one of the at least two electrodes comprises an uncoated plate that is made from titanium Grade 1 , titanium Grade 2 or titanium Grade 5, and

- the device comprises at least one functional group of two electrodes and at least one intermediate plate extending between the electrodes, in which case the at least one intermediate plate of the at least one functional group is optionally made from titanium Grade 1 , titanium Grade 2 or titanium Grade 5 and is provided with a mixed metal coating.

In the context of the invention, the electrode functioning as cathode can be provided as an uncoated plate, whereas the electrode functioning as anode can be provided as a plate to which a mixed metal coating is applied. Also the optional at least one intermediate plate can be provided with a mixed metal coating. Generally speaking, it is useful if the coating comprises a material that is known to have a large number of free electrons at and underneath the exterior surface of the coating. The use of a mixed metal oxide coating, as known from existing processes of splitting water under the influence of electric energy, is not applicable to the context of the invention. The number of intermediate plates can be chosen freely in the context of the invention. In this respect, a general principle is that more intermediate plates are needed in case distilled water is used. The at least one intermediate plate functions to distribute or reduce local electric peak current on the cathode and anode, and also as additional capacitor in the cell.

It is possible to have more than one functional group including a set of two electrodes and possibly also at least one intermediate plate in the cell, in which case it may be advantageous to initiate operation of the respective cells in a certain sequence and not simultaneously, so as to have more or less continuous and even hydrogen production in the cell. Further, it is also possible that the device comprises more than one cell.

Further, in conformity with what is mentioned in the foregoing, in terms of the device, it is practical if the device comprises an arrangement configured to receive hydrogen and oxygen from the cell, to separate the hydrogen and the oxygen, and to discharge the hydrogen and the oxygen to separate discharge positions and/or if the device comprises a water supply system configured to supply water to the cell, which water supply system includes a filter unit configured to filter at least metal particles from tap water. The device may also be suitable for use with another type of water such as distilled water or sea water, or may be designed so as to be adaptable to different types of water. For example, in the case of sea water, a mechanism for removing salt from the water is needed. In order to guarantee effective and safe operation of the device, the device may further comprise components such as a hydrogen flashback arrestor or a catalyst including a nickel mesh and granulate. In respect of the latter, it is noted that such a type of catalyst is useful for reducing the speed of an output flow of hydrogen.

In the context of the invention, by no means the electric energy source needs to be a high voltage source. On the contrary, it is demonstrated in the context of the invention that it suffices if the electric energy source is a DC voltage source that is configured to supply electric energy at a voltage in a range of 15 to 100 V. A practical example of a value of the voltage is 24 V. Supplying the electric energy in ultra-short pulses of the low DC voltage to the electrodes suffices to trigger the process of charging the cell until discharge takes place and the supply of electric energy can be terminated or at least significantly reduced. It is practical if the controller arrangement is configured to perform pulse width modulation of the voltage.

The invention further relates to a method for generating at least one of heat and electric energy from hydrogen, comprising the method for producing hydrogen from water as defined and described here before, receiving produced hydrogen at a reaction position, and supplying oxygen to the hydrogen at the reaction position. The reaction position may be in a reaction unit, wherein it may be practical if such a reaction unit is a hydrogen burner or a hydrogen fuel cell. Likewise, the invention relates to a device designed to generate at least one of heat and electric energy from hydrogen, comprising a device designed to produce hydrogen from water as defined and described here before, combined with a reaction unit configured to receive produced hydrogen from the device designed to produce hydrogen from water and to supply oxygen to the hydrogen. The device designed to generate at least one of heat and electric energy from hydrogen can function as an on demand system, wherein the device designed to produce hydrogen from water is operated every time there is a need for the at least one of heat and electric energy. The oxygen used in the reaction unit may be oxygen produced besides the hydrogen and/or oxygen supplied from another source, particularly a source of oxygen or air.

The invention also relates to an entity comprising a device designed to generate at least one of heat and electric energy from hydrogen as defined and described here before. It may be so that the entity is chosen from a group including a vehicle, a power system of a building, a temperature regulating system of a building, and an electric power plant. In this respect, it is noted that the invention covers any possible application of hydrogen, particularly any possible industrial application of hydrogen.

The above-described and other aspects of the invention will be apparent from and elucidated with reference to the following detailed description of a device designed to produce hydrogen from water and the way in which the device functions when operated.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in greater detail with reference to the figures, in which equal or similar parts are indicated by the same reference signs, and in which:

Figure 1 shows a schedule of components of a device designed to produce hydrogen from water;

Figure 2 illustrates how a controller arrangement of the device is connected to other components of the device;

Figures 3 to 5 show views of a body part of a cassette comprising a cell of the device; Figure 6 shows the view of the body part from figure 3 again, with various plates inserted in the body part;

Figures 7 to 9 show views of a bottom part of the cassette; and Figures 10 to 12 show views of a top part of the cassette.

DETAILED DESCRIPTION OF EMBODIMENTS

The invention relates to a way of producing hydrogen from water that involves very high energy efficiency. Generally speaking, according to the invention, a quantity of water contained in a cell is operated in switched mode conditions. The water is alternately put to a plasma condition and subsequently released, as it were, to go back from the plasma condition to the normal condition, wherein in the latter phase, a natural process takes place in the water during which both hydrogen and oxygen are generated. The first phase, which will hereinafter be referred to as charging phase, is invoked by supplying electric energy to a set of electrodes arranged in the water at a distance relative to each other, thereby charging the combination of the electrodes and the water as if the electrodes are the plates of a capacitor and the water is the dielectric of the capacitor, while during the second phase, which will hereinafter be referred to as discharging phase, the supply of electric energy is terminated or at least drastically reduced, as the natural process during which both hydrogen and oxygen are generated can take place without a further supply of electric energy.

The invention involves controlling the supply of electric energy in compliance with the behavior of the water. As soon as the water reaches the plasma condition as a result of the supply of electric energy during the charging phase, the water starts behaving differently than in the normal condition. Likewise, when the water returns to the normal condition, the specific behavior of the water related to the plasma condition is absent. These facts can be used for controlling the supply of electric energy in compliance with the behavior of the water. Both the end of the charging phase being the start of the discharging phase and the end of the discharging phase being the start of the charging phase are not imposed on the water, but are determined by the water in a natural way. This is enabled by the invention through continuously setting an extent to which energy is transmitted from the electric energy source to the electrodes in dependence on an actual value of at least one parameter related to the condition of the water in the cell and/or an actual time derivative of such at least one parameter. By choosing the at least one parameter so as to be a parameter that is different in the normal condition and the plasma condition of the water, controlling the supply of energy in dependence on the at least one parameter can be done in perfect harmony with the highly dynamic process taking place in the water through time. When it comes to supply of energy, the water is allowed to demand exactly what is needed at any time, as it were. A practical example of the at least one parameter is the electrical resistance of the water between the electrodes.

The charging phase takes no more than supplying a pulse of low DC voltage electric energy to the electrodes, wherein the time duration of the pulse can be as short as a duration in a range of 3 to 4 nanoseconds. The time of the discharging phase appears to be in more or less the same range. The voltage at which the discharging phase starts is determined by the characteristics of the water, and can be in a range of 16 V to 70 V for filtered tap water, or at a higher value for distilled water. The discharging phase actually involves a chain reaction in the water, wherein there is no need for additional external energy, as suggested earlier. The plasma field invokes micro cavities in the water. A high amount of energy is released locally when the micro cavities implode, and a fraction of water molecules are caused to split as a result. Micro plasma balls are generated, which create natural frequencies in the order of as high as tens of MHz, depending on the characteristics of the water. The end of the discharging phase is when there are no more imploding micro cavities, and a practical way to find this end of the discharging phase involves monitoring the electrical resistance of the water between the electrodes, as this parameter immediately increases to a larger value at that point. This fact can be used to immediately trigger a new pulse of electric energy, i.e. to re-initiate the charging phase. Thus, when the invention is applied, a process during which a charging phase and a discharging phase continuously alternate is obtained, wherein the charging phase requires no more than an ultra-short pulse of low DC voltage and the discharging phase can do without a supply of external energy, or with only a minimum supply of external energy, and wherein the hydrogen that is desired as the outcome of the process is generated during the discharging phase.

A general set-up of a practical embodiment of a device 100 that is configured to produce hydrogen from water in accordance with the principles of the invention is illustrated in figures 1 and 2, in which components of the device 100 are diagrammatically shown. The device 100 will hereinafter be referred to as hydrogen producing device 100.

The component of the hydrogen producing device 100 where the actual hydrogen production process is to take place during operation of the device 100 is a cassette 10 which comprises at least one cell 11 , 12. Figure 2 illustrates the option of having two cells 11 , 12 in the hydrogen producing device 100. A practical possibility in respect of the design of each of the cells 11 , 12 will be discussed later with reference to figures 3 to 12. Each of the cells 11 , 12 is configured to contain water and comprises an internal space 13 that is in fluid communication with a water supply system 20 through a conduit system 21 in which a water supply valve 22 is arranged. The water supply system 20 may be connected to any suitable tap water source, such as a large container filled with tap water, or the public water supply system. The water supply system 20 is equipped with a filter unit 23 configured to filter at least metal particles from the tap water. In this respect, it is noted that in order to obtain proper functioning of the hydrogen producing device 100, it may particularly be practical if the electrical resistance of the filtered tap water is in a range of 0.5 MQ/cm² to 1 .0 MQ/cm². In the case of distilled water, a higher value of the electrical resistance is applicable. It is possible to have a design of the hydrogen producing device 100 in which the device 100 is suitable or adaptable to process distilled water instead of filtered tap water. The scope of the invention is not restricted to a particular type of water.

Besides the water supply system 20, a water discharge system 24 including a water discharge conduit 25 and a water discharge valve 26 which allows drainage of water from the cassette 10 in cases of service and maintenance, for example, is connected to the cassette 10. The cassette 10 is also provided with a venting system 27 including a venting conduit 28 and a venting valve 29. The venting valve 29 functions to avoid counterpressure in the water supply system 20 when water is supplied to the cassette 10, and to allow an intended level of water of the cassette 10 to be actually reached. The venting valve 29 also functions to avoid the generation of vacuum when water is drained from the cassette 10 through the water discharge system 24.

The hydrogen producing device 100 comprises an electric circuit 30 including an electric energy source 31 and functional groups 32 including electrodes arranged in the internal space 13 of the respective cells 11 , 12, at a distance relative to each other. The electric energy source 31 is configured to be connected to the mains, and is configured to convert AC electric energy in a voltage range of 90 V to 240 V, at a frequency in a range of 50 Hz to 60 Hz, to a DC voltage of 24 V, for example.

The hydrogen producing device 100 further comprises a controller arrangement 40 that is configured to realize functioning of the device 100 as envisaged. The controller arrangement 40 is electrically connected to the electric energy source 31 and comprises a boost up converter and a pulse width modulation controller. A detecting arrangement 41 is provided to detect an actual value of at least one parameter related to the condition of the water in the respective cells 11 , 12. In the present example, the at least one parameter is the electrical resistance of the water between the electrodes of a functional group 32, and the detecting arrangement 41 comprises a sensor 42 configured to detect the electrical resistance as mentioned. Such a sensor may comprise a Wheatstone bridge with two input areas of the Wheatstone bridge being located in the internal space 13 of the respective cells 11 , 12, at a distance relative to each other, or may be designed in any other suitable way.

Each of the water supply valve 22, the water discharge valve 26 and the venting valve 29 mentioned earlier may be a solenoid valve and is also controlled by the controller arrangement 40. Further components connected to the controller arrangement 40 include a temperature sensor 43, a cooling system 44 including one or more fans, a pressure switch 45, a leakage sensor 46, and a start/stop button 47. In general, it is practical if the device 100 comprises a panel including various user interface elements such as one or more displays, buttons and/or touch screens. At an output side of the cassette 10, a gas output system 50 is connected to the cassette 10, which gas output system 50 comprises a pressure switch 51 , a catalyst 52 configured to reduce speed of an output flow of hydrogen, a check valve 53, and a flashback valve 54.

During operation of the hydrogen producing device 100, supply of electric energy to the electrodes through time is controlled by means of the controller arrangement 40 on the basis of the actual value of the electrical resistance of the water between the electrodes, as detected by the detecting arrangement 41 . The fact is that the controller arrangement 40 is configured to set the extent to which energy is transmitted from the electric energy source 31 to the electrodes through setting one of an interrupted state and a closed state of the electric circuit 30. Hence, the value of the extent is zero in the interrupted state. In particular, the controller arrangement 40 is configured to set the closed state of the electric circuit when the electrical resistance of the water is at a first reference value, and to set the interrupted state of the electric circuit when the electrical resistance of the water has dropped from the first reference value to below a second reference value that is lower than the first reference value. A practical example of the first reference value is 1.0 MQ/cm², and a practical example of the second reference value is 0.5 MQ/cm². On the basis of the controller arrangement 40 being configured in this way, it is achieved that the supply of electric energy to the electrodes is terminated at the very moment the condition of the water changes from the normal condition to the plasma condition and the above- mentioned chain reaction caused by imploding cavities in the water starts, as the electrical resistance of the water between the electrodes decreases significantly at that moment, and that the supply of electric energy to the electrodes is restored at the very moment the chain reaction dies out and the condition of the water changes from the plasma condition to the normal condition, as the electrical resistance of the water between the electrodes increases significantly at that moment. Thus, in the present example, the electrical resistance of the water between the electrodes is taken as an indicator of the condition of the water, so that it is possible to control the supply of electric energy to the electrodes in full compliance with the invoked natural behavior of the water. In fact, it is the charged water that determines the functioning of the respective cells 11 , 12 and that controls the voltage and the frequencies as necessary between the electrodes. It is an achievement of the invention that the hydrogen production process is controlled in a way that involves taking into account the actual and natural behavior/response of the water in the process.

The hydrogen producing device 100 can be included in a device that is designed to generate at least one of heat and electric energy from hydrogen, and that comprises a reaction unit configured to receive produced hydrogen from the hydrogen producing device 100 and to supply oxygen to the hydrogen. The at least one of heat and electric energy can be applied in numerous possible ways, such as for driving a vehicle, supplying electric energy to an electric system of a building, and supplying heat to a heating system of a building.

Figures 3 to 12 shows respective components of a cassette 10 comprising one cell 11 including four functional groups 32, wherein figures 3 to 5 show views of a body part 60 of the cassette 10, figure 6 illustrates how the body part 60 is used to support a number of plates 33, 34, 35 of the cell 11 , figures 7 to 9 show views of a bottom part 70 of the cassette 10, and figures 10 to 12 show views of a top part 80 of the cassette 10. In an assembled condition of the cassette 10, the body part 60 is sandwiched between the bottom part 70 and the top part 80. The respective parts 60, 70, 80 can be connected to each other in any suitable way. In the present example, each of the respective parts 60, 70, 80 is provided with holes 14 at a peripheral position, which holes 14 align in the assembled condition of the cassette 10 so as to form channels for allowing a threaded rod, a bolt or another connection means to pass. In the assembled condition of the cassette 10, the internal space 13 of the cell 11 is composed of the respective internal spaces 13a, 13b, 13c of the combined parts 60, 70, 80. The body part 60 is also provided with open channels 62 at a peripheral position, which open channels 62 function to promote the circulation of water in the cell 11 .

With reference to figure 6, it is noted that the cell 11 may be equipped with plate-shaped electrodes 33, 34 and intermediate plates 35. For the purpose of holding the plates 33, 34, 35, the respective parts 60, 70, 80 are equipped with sets of grooves 61 , 71 , 81 for receiving respective areas of the plates 33, 34, 35. In the present example, as seen from top to bottom in figure 6, the sequence of plates 33, 34, 35 is as follows:

1) an intermediate plate 35, i.e. a plate which is not included in the electric circuit 30,

2) an electrode 33 functioning as cathode in the cell 11 , which will hereinafter be referred to as cathode electrode 33,

3) an intermediate plate 35,

4) an electrode 34 functioning as anode in the cell 11 , which will hereinafter be referred to as anode electrode 34,

5) an intermediate plate 35,

6) a cathode electrode 33,

7) an intermediate plate 35,

8) an anode electrode 34,

9) an intermediate plate 35,

10) a cathode electrode 33,

11) an intermediate plate 35,

12) an anode electrode 34,

13) an intermediate plate 35,

14) a cathode electrode 33, and

15) an intermediate plate 35.

In figure 6, in order to facilitate distinguishing one type of plate 33, 34, 35 from another, the cathode electrode 33 is depicted as a dashed line, the anode electrode 34 is depicted as a dotted line, and the intermediate plate 35 is depicted as a continuous line.

Both the plate-shaped cathode electrodes 33 and the intermediate plates 35 may be made from titanium Grade 1 , titanium Grade 2 or titanium Grade 5 and be provided with a mixed metal coating, while the plate-shaped anode electrodes 34 may be made from titanium Grade 1 , titanium Grade 2 or titanium Grade 5 as well, yet may be without any coating. In general, it is advantageous if the plates 33, 34, 35 are provided as metal plates which are capable to survive the imposed reactor conditions for a sufficiently long time. A practical example for the distance between two adjacent plates 33, 34, 35 is 3 mm. In the case of a larger distance, the pulse of electric energy supplied to the water during the charging phase would need to be provided at higher voltages, while the electric current would be at a lower level.

The bottom part 70 is provided with a holder 72 for receiving and holding the controller arrangement 40. A bottom wall 73 of the bottom part 70 is provided with holes 74, 75, 76 for allowing passage of electrically conductive connecting wires from the controller arrangement 40 to the internal space 13b of the bottom part 70. With reference to figure 7, it is noted that the holes 74, 75, 76 include four holes 74 as can be seen at the left of the bottom wall 73 for enabling connection of the respective cathode electrodes 33 to the controller arrangement 40, two holes 75 as can be seen at the middle of the bottom wall 73 for enabling connection of two electrodes constituting two input areas of the sensor 42 of the detecting arrangement 41 , and three holes 76 as can be seen at the right of the bottom wall 73 for enabling connection of the respective anode electrodes 34 to the controller arrangement 40. Figure 9 illustrates the option of an advantageous use of separation plates 77 in the bottom part 70, which separation plates 77 are designed to perform a stabilizing function on the cathode electrodes 33, the anode electrodes 34 and the intermediate plates 35 by absorbing vibrations.

The top part 80 is provided with openings 82 for letting out hydrogen and oxygen produced during operation of the cell 11 , and also has openings 83 enabling communication between a gas pressure sensor and the internal space 13 of the cell 11 . Further, the top part 80 is provided with a separation wall 84 having a number of openings, which separation wall 84 has a function in reducing the oxygen.

The cassette 10 having the features as described here before is of a design that is both compact and robust, and that is useful to enable the operation of the cell 11 to produce hydrogen as described earlier, and represents only one practical possibility existing in the context of the invention. As suggested earlier, the hydrogen producing device 100 may comprise more than one cell 11 , 12, in which case the device 100 may comprise as many single-cell cassettes as cells 11 , 12, or a multiplecell cassette that is designed so as to include all of the cells 11 , 12. It will be clear to a person skilled in the art that the scope of the invention is not limited to the examples discussed in the foregoing, but that several amendments and modifications thereof are possible without deviating from the scope of the invention as defined in the attached claims. It is intended that the invention be construed as including all such amendments and modifications insofar they come within the scope of the claims or the equivalents thereof. While the invention has been illustrated and described in detail in the figures and the description, such illustration and description are to be considered illustrative or exemplary only, and not restrictive. The invention is not limited to the disclosed embodiments. The drawings are schematic, wherein details which are not required for understanding the invention may have been omitted, and not necessarily to scale.

Devices for producing hydrogen are known which are designed to do so at high voltage and low frequency. Contrariwise, the hydrogen producing device 100 according to the invention is designed to function at low voltage and high frequency as determined by the characteristics of the water that is made to decompose, wherein the water is continually and alternately charged and discharged, and wherein both the charging phase and the discharging phase take no more than a few nanoseconds.

Notable aspects of the invention are summarized as follows. In the field of producing hydrogen from water, a method is provided that comprises providing a device 100 comprising an electric circuit 30 including an electric energy source 31 and at least two electrodes 33, 34, and further comprising a cell 11 , 12 having an internal space 13 in which the water is present and in which the at least two electrodes 33, 34 are arranged at a distance relative to each other, and continuously setting an extent to which energy is transmitted from the electric energy source 31 to the electrodes 33, 34 in dependence on at least one of an actual value of at least one parameter related to the condition of the water in the cell 11 , 12 and an actual time derivative of such at least one parameter. In this way, it is achieved that the hydrogen production process is controlled in a way that involves taking into account the actual and natural behavior/response of the water in the process, as a result of which the hydrogen production process can be highly energy-efficient.

Claims

1 . Method for producing hydrogen from water, comprising:

- providing a device (100) comprising an electric circuit (30) including an electric energy source (31) and at least two electrodes (33, 34), and further comprising a cell (11 , 12) having an internal space (13) in which the water is present and in which the at least two electrodes (33, 34) are arranged at a distance relative to each other, and

- continuously setting an extent to which energy is transmitted from the electric energy source (31) to the electrodes (33, 34) in dependence on at least one of an actual value of at least one parameter related to the condition of the water in the cell (11 , 12) and an actual time derivative of such at least one parameter.

2. Method according to claim 1 , further comprising:

- continuously monitoring the actual value of the at least one parameter related to the condition of the water in the cell (11 , 12).

3. Method according to claim 1 or 2, wherein a controller value of the extent to which energy is transmitted from the electric energy source (31) to the electrodes (33, 34) is determined by continuously comparing the at least one of the actual value of the at least one parameter related to the condition of the water in the cell (11 , 12) and the actual time derivative of such at least one parameter to a respective reference, and wherein the extent to which energy is transmitted from the electric energy source (31) to the electrodes (33, 34) is set in accordance with the controller value.

4. Method according to claim 3, wherein the reference is set in dependence on a value of the at least one parameter related to the condition of the water in the cell (11 , 12) for an initial condition of the water in the cell (11 , 12).

5. Method according to any of claims 1 -4, wherein setting the extent to which energy is transmitted from the electric energy source (31) to the electrodes (33, 34) involves setting one of two values of the extent, one of the two values being significantly lower than the other of the two values.

6. Method according to any of claims 1 -5, wherein setting the extent to which energy is transmitted from the electric energy source (31) to the electrodes (33, 34) involves setting one of an interrupted state and a closed state of the electric circuit (30).

7. Method according to any of claims 1 -6, wherein the at least one parameter related to the condition of the water in the cell (11 , 12) comprises the electrical resistance of the water between the at least two electrodes (33, 34).

8. Method according to claim 7, wherein the actual value of the electrical resistance of the water is measured by means of a Wheatstone bridge.

9. Method according to claim 7 or 8 insofar as dependent on claim 5, wherein the highest value of the extent to which energy is transmitted from the electric energy source (31) to the electrodes (33, 34) is set when the electrical resistance of the water is at a first reference value, and wherein the lowest value of the extent is set when the electrical resistance of the water has dropped from the first reference value to below a second reference value that is lower than the first reference value.

10. Method according to claim 9, wherein at least the first reference value is determined in dependence on a value of the electrical resistance of the water in an initial condition in the cell (11 , 12).

11 . Method according to any of claims 1 -10, wherein hydrogen and oxygen are received from the cell (11 , 12), wherein the hydrogen and the oxygen are separated, and wherein the hydrogen and the oxygen are discharged to separate discharge positions. 12. Method according to any of claims 1 -11 , wherein the water in the cell (11 ,

12) is filtered tap water.

13. Method for generating at least one of heat and electric energy from hydrogen, comprising the method for producing hydrogen from water according to any of claims 1-12, receiving produced hydrogen at a reaction position, and supplying oxygen to the hydrogen at the reaction position.

14. Method according to claim 13, wherein the reaction position is in a reaction unit being either one of a hydrogen burner and a hydrogen fuel cell.

15. Device (100) designed to produce hydrogen from water, comprising:

- an electric circuit (30) including an electric energy source (31) and at least two electrodes (33, 34),

- a cell (11 , 12) having an internal space (13) configured to contain the water, in which the at least two electrodes (33, 34) are arranged at a distance relative to each other,

- a detecting arrangement (41) configured to detect an actual value of at least one parameter related to the condition of the water in the cell (11 , 12), and

- a controller arrangement (40) configured to receive and process input from the detecting arrangement (41) and to continuously set an extent to which energy is transmitted from the electric energy source (31) to the electrodes (11 , 12) in dependence on the input from the detecting arrangement (41).

16. Device (100) according to claim 15, wherein the detecting arrangement (41) is configured to continuously monitor the actual value of the at least one parameter related to the condition of the water in the cell (11 , 12), wherein the controller arrangement (40) is configured to determine a controller value of the extent to which energy is transmitted from the electric energy source (31) to the electrodes (33, 34) by continuously comparing at least one of the actual value of the at least one parameter related to the condition of the water in the cell (11 , 12) and an actual time derivative of such at least one parameter to a respective reference, and to set the extent to which energy is transmitted from the electric energy source (31) to the electrodes (33, 34) in accordance with the controller value.

17. Device (100) according to claim 16, wherein the controller arrangement (40) is configured to set the reference in dependence on input from the detecting arrangement (41) related to an initial condition of the water.

18. Device (100) according to any of claims 15-17, wherein the controller arrangement (40) is configured to set the extent to which energy is transmitted from the electric energy source (31) to the electrodes (33, 34) at an appropriate one of two values of the extent, one of the two values being significantly lower than the other of the two values.

19. Device (100) according to any of claims 15-18, wherein the controller arrangement (40) is configured to set the extent to which energy is transmitted from the electric energy source (31 ) to the electrodes (33, 34) through setting one of an interrupted state and a closed state of the electric circuit (30).

20. Device (100) according to any of claims 15-19, wherein the at least one parameter related to the condition of the water in the cell (11 , 12) comprises the electrical resistance of the water between the at least two electrodes (33, 34).

21 . Device (100) according to claim 20, wherein the detecting arrangement (41 ) comprises at least one sensor (42) configured to detect the electrical resistance of the water between the at least two electrodes (33, 34).

22. Device (100) according to claim 21 , wherein the at least one sensor (42) comprises a Wheatstone bridge.

23. Device (100) according to any of claims 15-22, wherein at least one of the at least two electrodes (33, 34) comprises a plate that is made from titanium Grade 1 , titanium Grade 2 or titanium Grade 5 and that is provided with a mixed metal coating.

24. Device (100) according to any of claims 15-23, wherein at least one of the at least two electrodes (33, 34) comprises an uncoated plate that is made from titanium Grade 1 , titanium Grade 2 or titanium Grade 5.

25. Device (100) according to any of claims 15-24, comprising at least one group (32) of two electrodes (33, 34) and at least one intermediate plate (35) extending between the electrodes (33, 34).

26. Device (100) according to claim 25, wherein the at least one intermediate plate (35) of the at least one group (32) is made from titanium Grade 1 , titanium Grade 2 or titanium Grade 5 and is provided with a mixed metal coating.

27. Device (100) according to any of claims 15-26, comprising an arrangement configured to receive hydrogen and oxygen from the cell, to separate the hydrogen and the oxygen, and to discharge the hydrogen and the oxygen to separate discharge positions.

28. Device (100) according to any of claims 15-27, comprising a water supply system (20) configured to supply water to the cell (11 , 12), which water supply system (20) includes a filter unit (23) configured to filter at least metal particles from tap water.

29. Device (100) according to any of claims 15-28, wherein the electric energy source (31) is a DC voltage source configured to supply electric energy at a voltage in a range of 15 to 100 V.

30. Device (100) according to claim 29, wherein the controller arrangement (40) is configured to perform pulse width modulation of the voltage.

31 . Device (100) according to any of claims 15-30, comprising at least one of a hydrogen flashback arrestor (54) and a catalyst (52) including a nickel mesh and granulate.

32. Device designed to generate at least one of heat and electric energy from hydrogen, comprising a device (100) designed to produce hydrogen from water according to any of claims 15-31 and a reaction unit configured to receive produced hydrogen from the device (100) designed to produce hydrogen from water and to supply oxygen to the hydrogen.

33. Device according to claim 32, wherein the reaction unit comprises one of a hydrogen burner and a hydrogen fuel cell.

34. Entity comprising a device designed to generate at least one of heat and electric energy from hydrogen according to any of claims 31-33.

35. Entity according to claim 24, chosen from a group including a vehicle, a power system of a building, a temperature regulating system of a building, and an electric power plant.