EP2349920A1

EP2349920A1 - Device for producing hydrogen from a plasma with electron cyclotron resonance

Info

Publication number: EP2349920A1
Application number: EP09753153A
Authority: EP
Inventors: Denis Hitz; Marc-Yves Delaunay
Original assignee: Commissariat a lEnergie Atomique CEA; Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Current assignee: Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Priority date: 2008-09-30
Filing date: 2009-09-29
Publication date: 2011-08-03
Also published as: US20110262314A1; FR2936506A1; WO2010037962A1

Abstract

The invention relates to a device (1) for producing hydrogen from ECR plasma, comprising a sealed vacuum chamber (2), water vapour injection means (11) high frequency wave injection means (11) for injecting to the chamber (2), a magnetic structure (3, 4, 5, 6) for generating a magnetic field in the chamber (2) and generate a layer of plasma following the lines of flux (12), the magnetic field module being designed as a mirror with a resonance zone (21) for dissociating the water molecules introduced in the vapour phase and to ionise the products of dissociation. The device (1), comprises a cryogenic condenser (8), arranged between the sealed chamber (2), to freeze the oxygen coming from the dissociation without freezing the hydrogen from the and means (7, 13) for recovering the hydrogen from the dissociation, the oxygen being trapped by the condenser (8).

Description

Device for producing hydrogen from a plasma resonance electron plasma

The present invention relates to a device for producing hydrogen from an electron cyclotron resonance plasma.

Hydrogen (H ₂ ) appears today as a very interesting energy vector, which is expected to become increasingly important and which could, in the long term, be a good substitute for oil and fossil fuels, whose reserves will decline sharply in the coming decades. In this perspective, it is necessary to develop efficient processes for the production of hydrogen.

Although many processes have been described for producing hydrogen from different sources, many of these processes are unsuitable for limiting greenhouse gases.

A first technique is to use steam reforming. This is a technique for converting light hydrocarbons such as methane into synthesis gas by reaction with water vapor on a catalyst. The two main chemical reactions of this method are the production of synthesis gas and the conversion of CO: CH ₄ + H ₂ O → co + 3H ₂ co + H ₂ O → co ₂ + H ₂ the overall balance being CH ₄ + 2H ₂ O → CO ₂ + 4H ₂

One of the major problems of this synthetic route is that it generates, as by-products, significant amounts of greenhouse gases of CO ₂ type.

A second method is to use a partial oxidation technique: it is an exothermic technique and generally without oxidation catalyst of products such as natural gas, heavy oil residues, coal. The production of synthesis gas is given by the reaction:

C _n H _1n + ( ⁿ Δθ ₂ → nCO + ( ^m /) H ₂ The conversion of carbon monoxide is given by the reaction: nCO + nH ₂ 0 → nCO ₂ + nH ₂ .

Like reforming, this technique produces a significant amount of carbon dioxide. It may also be mentioned a third technique using the direct thermal decomposition of water; such a technique would require extremely high temperatures of the order of 3000 to 4000 K (the use of a catalyst makes it possible to reduce this temperature, which nevertheless remains very high, close to 1400 K). This production technique is envisaged by using high temperature nuclear reactors cooled by a gaseous coolant such as helium (in the case of so-called fourth generation reactors of the HTR "High Temperature Reactor" type). By its principle, it is a technique that is related to the production of uranium. The other disadvantage is that it is unthinkable to use this method for small productions of hydrogen.

A fourth way is to perform an electrolysis of water: it is a technique of dissociation of water by passage of an electric current according to the reaction:

H ₂ O → H ₂ + -O ₂ This reaction, whose enthalpy is ΔH = 285 kJ.mol ^"1 (at 298 K and 1 bar) is carried out according to the following method: an electrolyte cell consists of two electrodes , anode and a cathode, connected to a direct current generator The electrodes are immersed in an electrolyte serving as a conducting medium This electrolyte is generally an acidic or basic aqueous solution, a proton exchange membrane (H ⁺ ) or an oxygen ion conducting membrane (O ^{2 "} ).

This technique poses some difficulties, however; thus the electrodes corrode in time. Moreover, such a process requires the permanent adjustment of the concentrations and the use of membranes that are either fragile for organic membranes or low yield for mineral membranes. A fifth solution is to perform a decomposition of water by thermochemical cycle (CTC): this process uses a series of chemical reactions. An example is the use of the iodine-sulfur cycle based on the decomposition of two acids at high temperature: sulfuric acid produces oxygen and sulfur dioxide, and hydrogen iodide produces hydrogen and iodine.

The disadvantage of this technique is the implementation of rather complex chemical reactions producing, in addition to hydrogen, many other elements such as sulfur in the case of the iodine-sulfur cycle or the Fe ₃ O ₄ and the HBr in the case of the UT-3 cycle.

A sixth way considered is biomass: obtained by photosynthesis of carbon dioxide and water, it uses solar energy to produce molecules of the type C ₆ H ₉ O ₄ . Thereafter there is a thermochemical treatment according to the reaction: C ₆ _{9 9} O ₄ + 2H ₂ O + SSOkJ → 6CO + ¹ HH ₂

Gasification with water vapor at about 900 ° C. then produces synthesis gas (CO + H ₂ O). A hydrogen supplement is then obtained by the "gas shift" reaction:

6CO + 6H ₂ O → 6CO ₂ + 6H ₂ Again, the main disadvantage of this technique lies in its production of carbon dioxide.

A seventh technique involves the photo-electrolysis of water: it is a process that uses the dissociation of the water molecule by an electric current produced by the illumination of a semiconductor photocatalyst (TiO ₂ , AsGa).

This process does not produce greenhouse gas gas but has a relatively low conversion efficiency.

Another method of producing hydrogen gas by microwave plasma is proposed in document WO2006 / 123883. This method uses the dissociation of gaseous molecules by electronic impact. The disclosed method consists in injecting a microwave power into a dielectric tube containing a gas or a vapor of the H ₂ O or CH _{4 type.} under reduced pressure (50-300 torr). This microwave power causes ionization and / or dissociation of the gas thus releasing hydrogen (initiation of a microwave plasma). At the end of the tube, a separator in a palladium material separates the hydrogen by gaseous diffusion.

Another method of producing hydrogen from water molecules is described in WO2005 / 005009. The disclosed method consists in placing the water molecules in an electromagnetic field to excite the molecules by thermal agitation until their excitation energy exceeds the binding energy of the H and O atoms composing the molecule. water.

Another method of producing hydrogen by injecting water vapor into a plasma is described in US2004 / 0265137. This patent describes a process for obtaining hydrogen from the dissociated vapor in a plasma. The document mentions in particular the use of the electron cyclotron resonance (ECR) to produce said plasma. Compared to the hydrogen production methods previously mentioned, the use of a RCE plasma machine has many advantages:

- continuous and stable operation; - no implementation of high temperatures;

- no wear (very long usage time due to lack of filament or electrodes);

- no production of carbon or carbon compounds;

- no use of chemical complexes; - low cost, if the magnetic structure is made of permanent magnets. However, despite the advantages mentioned above, a major problem of such a plasma machine that breaks, by electronic impact, the bonds of the water molecule, is the separation of the products formed.

The insertion of a dielectric is a possible solution. This method, however, has the disadvantage of using rare and expensive compounds. In this context, the present invention aims to provide a device for producing hydrogen from water with an electron cyclotron resonance plasma that does not necessarily require fields. magnets and allowing efficient dissociation of water molecules and simple separation of the products formed.

To this end, the invention proposes a device for producing hydrogen from an electron cyclotron resonance plasma comprising: a vacuum sealed chamber intended to contain a plasma,

means for injecting water vapor into said chamber,

means for injecting a high-frequency wave inside said chamber; a magnetic structure for generating a magnetic field in said chamber and generating a plasma layer along the magnetic field lines; the module of said field; magnetic sensor having a magnetic mirror configuration with at least one electron cyclotron resonance zone for at least partially dissociating the water molecules introduced in the vapor phase and for at least partially ionizing the products of the dissociation, said device being characterized in that it comprises :

at least one cryogenic condenser, placed in said sealed chamber, for freezing the oxygen resulting from the dissociation without freezing the hydrogen resulting from the dissociation,

means for recovering the hydrogen resulting from the dissociation, the oxygen being trapped by said cryogenic condenser. Vacuum chamber means a chamber in which a working pressure of less than or equal to 5.10 ^"3 mbar prevails, said working pressure corresponding substantially to the partial pressure of water vapor injected into the chamber.

Thanks to the invention, a production of hydrogen is obtained from the steam. The device according to the invention is based on the combined use of a cyclotron resonance plasma of electrons and at least one selective cryogenic condenser. This non-CO ₂ emitting device does not use electrodes, membranes or high temperatures. Thanks to the electron cyclotron resonance principle, at each passage in the vicinity of the resonance zone, the electrons will acquire energy. They will then be able to dissociate the water molecules, then ionize, at least partially, the dissociation products. Thanks to the electroneutrality of the plasma, these ions will follow the electrons on the magnetic field lines.

The device according to the invention makes it possible to work continuously for several months without interruption or maintenance. The device may, depending on its size, have a plasma volume ranging from a few cm ³ to several liters, or even m ³ .

By observing the phase diagrams of the hydrogen and oxygen elements for the low temperatures shown in FIG. 2, the operating pressure of the considered plasma machine being less than 5 × 10 ^-3 mbar, it is noted that there is a temperature range where it It is possible to cryocondense oxygen while keeping the hydrogen in gaseous form, for example, at 5 × 10 ^-3 mbar, this temperature range is from 6.4K to 42K. Thus, by using one or more cryogenic condensers (for example one or more cooled plates) at a temperature such that the two elements, hydrogen and oxygen, composing the plasma are in different phases (hydrogen gas and solid oxygen), it is possible to trap the oxygen in solid form without trapping the hydrogen that will be recovered by other means. The condenser temperature depends on partial hydrogen pressures from the initial density of the plasma which is itself a function of the microwave frequency injected. Oxygen being trapped, then hydrogen recovery means such as a conventional pumping system (turbomolecular pump for example) for pumping hydrogen are used. It is also possible to advantageously use the fact that the ionized particles follow, by electroneutrality of the plasma, the electrons which are guided by the magnetic field lines. Indeed, if the oxygen cryocondensation plates are placed in the magnetic field lines, it is then advantageous to place hydrogen cryocondensation plates outside the magnetic field lines. Thus, hydrogen and oxygen are fixed on cold walls inde- while it is sufficient to heat independently of each other to separately recover hydrogen and oxygen either in liquid form or in gaseous form.

It will be noted that, although using an electromagnetic field, the device according to the invention does not use a method of thermal agitation of the water molecules, but breaks the atomic bonds by collisions with the electrons of the plasma.

According to a particularly advantageous embodiment of the invention, said chamber comprises non-dissociated water recovery means, the field lines generated by said magnetic structure being curved with respect to the steam injection axis. said non-dissociated water recovery means being substantially arranged along the injection axis of the water vapor.

This advantageous embodiment makes it possible to solve the problem of the recovery of non-dissociated water molecules by the electrons of the plasma. Indeed, ionization and dissociation of water molecules is never complete; therefore, a significant amount of water molecules remains present. It is obviously interesting to recover these non-dissociated water molecules, for example to recycle them back into the chamber as a vapor. If the magnetic field lines were not curved, there would be no possibility to recycle the undissociated water. Indeed, non-dissociated water molecules are not guided by the magnetic field lines and preferentially in a straight line with respect to the steam injection nozzle. In other words, in a simple mirror axisymmetric, should be recovered in the same place and at the same time undissociated water and hydrogen and dissociated oxygen, which is difficult to achieve.

According to this advantageous embodiment, the magnetic field lines are bent in such a way that it is then possible to carry out at the same time the recycling operations of the undissociated water, the separation of the hydrogen and the oxygen, hydrogen recovery and oxygen recovery. The curved magnetic field lines thus make it possible to recover non-dissociated or ionized water vapor, by example on a condenser placed in a straight line with respect to the injection of steam.

The device according to the invention may also have one or more of the following characteristics, considered individually or in any technically possible combination:

said means for recovering non-dissociated water comprise a second chamber connected to said plasma chamber;

said second chamber is of tubular form;

said means for recovering non-dissociated water are formed by a condenser;

said means for recovering non-dissociated water are separated from said plasma chamber by a diaphragm device;

the device according to the invention comprises at least one non-dissociated water reinjection system in the vapor phase and issuing from said non-dissociated water recovery means;

- The device according to the invention comprises a grid having a mailing for stopping the propagation of high frequency waves so that said non-dissociated water recovery means are arranged in a zone without microwaves so substantially without plasma;

said cryogenic condenser for freezing the oxygen resulting from the dissociation without freezing the hydrogen resulting from the dissociation is at a temperature of between 6 and 41 K for an average pressure of between 10 ^-3 mbar and 5 × 10 ^-3 mbar in said chamber (temperature between 6 and 39 K for a pressure substantially equal to 10 ^"3 mbar and temperature between 6 and 41 K for a pressure substantially equal to 5X10 ^{" 3} mbar);

said cryogenic condenser for freezing oxygen is a solid or perforated cryogenic panel; said cryogenic condenser for freezing oxygen is arranged to intercept said field lines formed by said magnetic structure; said cryogenic condenser for freezing oxygen is a cryogenic panel which surrounds said field lines formed by said magnetic structure;

the device according to the invention comprises an enclosure capable of recovering oxygen when said cryogenic condenser for freezing oxygen is regenerated by raising the temperature;

said means for recovering the hydrogen resulting from the dissociation comprise a pump for pumping hydrogen in the gas phase; said means for recovering hydrogen from the dissociation comprise at least one cryogenic condenser for freezing hydrogen, said cryogenic condenser being at a temperature below the temperature of said at least one cryogenic condenser for freezing oxygen, said at least one at least one cryogenic oxygen freezing condenser is arranged to trap oxygen before said at least one cryogenic condenser for freezing hydrogen traps hydrogen.

the device according to the invention comprises:

A cryogenic condenser for freezing the hydrogen that can be regenerated by raising the temperature,

An enclosure capable of recovering hydrogen when said cryogenic condenser for freezing hydrogen is regenerated by raising the temperature;

the device according to the invention comprises: a first enclosure including:

• a first cryogenic condenser to freeze oxygen;

Optionally a first cryogenic condenser for freezing hydrogen; a second enclosure including:

• a second cryogenic condenser to freeze oxygen; • possibly a second cryogenic condenser to freeze hydrogen; each of said first and second chambers being capable of recovering oxygen and hydrogen independently of one another by regeneration, said regeneration being done by gradually raising the temperature so that the hydrogen first goes into the gas phase and is recovered and the oxygen then goes into the gas phase and is recovered.

said at least one cryogenic condenser for freezing hydrogen comprises at least one solid or perforated cryogenic panel; the device according to the invention comprises a negatively polarized grid placed forward with respect to the plasma, of said at least one cryogenic condenser for freezing hydrogen and / or of said at least one cryogenic condenser for freezing oxygen, so that said grid repels the electrons towards the plasma and attracts the ions; said at least one cryogenic condenser for freezing hydrogen and / or said at least one cryogenic condenser for freezing oxygen are capable of being negatively biased to repel electrons towards the plasma and attract the ions;

said means for recovering the hydrogen resulting from the dissociation are arranged so as not to intercept said magnetic field lines;

the device according to the invention comprises at least one catalyst surface for fixing the water molecules and increasing the dissociation efficiency of the water by electronic impacts of the plasma on said surface;

said catalyst surface is placed in the magnetic mirror zone, preferably between the resonance zones.

said magnetic structure comprises permanent magnets;

the magnetic structure comprises permanent magnets whose poles which face each other in the zone of injection of the water vapor are of the same nature North-North or South-South;

the magnetic structure comprises permanent magnets whose poles face each other, in the hydrogen recovery zone are of the same meaning, the magnetization values of these magnets being either identical or different;

the magnetic structure comprises permanent magnets whose poles which face each other in the hydrogen recovery zone are of opposite direction;

the permanent magnet situated in the zone of injection of the water vapor is of the same polarity as the magnet located in the zone of recovery of the hydrogen;

the magnetic structure comprises permanent magnets of different sizes and having either the same magnetization or different magnetizations;

the magnetic structure comprises coils at ambient temperature and / or superconducting coils at low or high critical temperature, called low or high Tc; the input window of said means for propagating a high-frequency wave inside said chamber is placed in a magnetic field whose module is greater than the modulus of the resonance magnetic field so that the plasma diffuses towards the chamber and thus avoid impacts of the plasma on said window; - The mirror ratio between the magnetic field maxima of said magnetic mirror and the magnetic field minimum of said magnetic mirror is strictly greater than 1 and preferably greater than 3 which represents an optimum value to allow good confinement of the plasma. Other features and advantages of the invention will emerge clearly from the description which is given below, as an indication and in no way limiting, with reference to the appended figures, among which:

FIG. 1 is a representation of the phase diagram of the water;

FIG. 2 is a representation of the phase diagrams of hydrogen and oxygen with the corresponding values at the triple point of each element;

- Figure 3 shows a top view of a first embodiment of the device according to the invention; - Figure 4 shows a top view of a second embodiment of the device according to the invention;

- Figure 5 shows a top view of a third embodiment of the device according to the invention; - Figure 6 shows a top view of a fourth embodiment of the device according to the invention;

- Figure 7 shows a top view of a fifth embodiment of the device according to the invention;

- Figure 8 shows a top view of a sixth embodiment of the device according to the invention;

- Figure 9 shows a top view of a seventh embodiment of the device according to the invention;

- Figure 10 shows a top view of an eighth embodiment of the device according to the invention; - Figure 1 1 shows a top view of a ninth embodiment of the device according to the invention;

- Figure 12 shows a top view of a tenth embodiment of the device according to the invention.

In all the figures, the common elements bear the same reference numbers.

Figures 1 and 2 have already been described above with reference to the general presentation of the invention.

FIG. 3 is a simplified representation in plan view of a device 1 for producing electron cyclotron resonance hydrogen according to a first embodiment of the invention.

The device 1 comprises:

- A sealed chamber 2 (called indifferently pregnant later) under vacuum;

- Four bars of permanent magnets 3, 4, 5 and 6 placed outside the chamber 2 (the bars typically have a height of between a few centimeters and 1 m); a cryogenic condenser 8 for trapping oxygen;

a condenser 7 for trapping hydrogen;

a pump 13 for pumping hydrogen gas;

a non-dissociated water recovery pipe 9 serving as a water vapor condenser;

a non-dissociated water recycling pump 10 in the vapor or liquid phase;

means for injecting water vapor into the chamber 2 and means for propagation of high frequency waves (formed by a waveguide or a coaxial cable equipped with a high-frequency, vacuum-tight, unrepresented window) ) inside the chamber 2, said injection and propagation means being illustrated by the arrow 11 and being located near the magnet 4.

The chamber 2 is under vacuum, the vacuum being effected by means of pumping ad hoc. In order to have the least possible impurities in the chamber 2, a residual vacuum of 10 ^"4 mbar minimum is necessary. However, it can lower the vacuum more (typically up to ^{10" 5} mbar) for even less impurities in the chamber 2. During the operation of the device 1 (ie after the injection of water vapor into the chamber), the working pressure of the chamber 2 is typically less than or equal to 5.10 ^"3 mbar, this pressure being related to the partial pressure of water vapor injected into the chamber 2.

The magnetic structure formed by the four bars 3, 4, 5 and 6 surrounding the chamber 2 produces inside the chamber 2 a magnetic field whose configuration is a magnetic mirror configuration having at least two maxima and a minimum magnetic field and at least one resonance zone (here a plurality of resonance zones represented by white dots 21 located on the field lines 12). It is a so-called minimum B structure: the electrons of the plasma are confined in a magnetic well. In a magnetized plasma device such as the device 1, the electrons are well confined, especially those which have a high velocity perpendicular to the magnetic field lines. When the microwaves are injected into the plasma, they tend to propagate through the plasma to the resonance zone. Indeed, the transfer of energy from the microwave power injected to the electrons of the plasma occurs at a magnetic field location B _rθS such that the electron cyclotron resonance condition is established, that is to say when there is equality between the pulsation of the high frequency wave ω _H F and the cyclotronic pulsation of the electron:

An unrepresented microwave generator is placed outside the chamber 2; this generator injects high frequency (HF) waves in the chamber 2 via the aforementioned propagation means. The frequency range of microwaves can range from GHz to 100 GHz, the most common generator being the 2.45 GHz magnetron commonly used for domestic microwave ovens. For a frequency of 2.45 GHz, a resonance magnetic field B _rθS = 0.0875 T is used. However, for miniature hydrogen production devices (for example, for example), it is also possible to use power transistors as an HF generator. Indeed, there are now field effect transistors capable of delivering about 60 W at 14.5 GHz.

The steam injection means in the chamber 2 are preferably placed near the microwave generation means (however, another location may also be chosen for reasons of convenience). The water is introduced into the plasma chamber 2 in the vapor phase. A simple way to obtain this vapor phase is to put a water tank in depression to a few tens of mbar.

Thanks to the electron cyclotron resonance principle, at each passage in the vicinity of the resonance zone, the electrons will acquire energy. They will then be able to dissociate the water molecules, then at least partially ionize the dissociation products. The electrons wind the magnetic field lines thanks to Laplace's law; thanks to the electroneutrality of the plasma, these ions will then follow the electrons on the magnetic field lines 12.

Since the best dissociation rate of the water is obtained for working pressures lower than 5 × 10 ^-3 mbar, this value is considered as a maximum working pressure in the chamber 2, especially since the electrons would not be more magnetically guided if we increase this pressure beyond 5X10 ^"3 mbar.

In the case that concerns us, that is to say the production of hydrogen from water vapor, only the population of electrons having a few tens of eV is useful. At the working pressure considered, the energy distribution of the electrons ranges from a few eV to a few tens of eV, this distribution being sufficiently wide to reach the desired ionization objective. Advantageously, the input window of the high frequency waves

(represented by the end of the arrow 11) is placed in an area of strong magnetic field. In this way, the plasma will diffuse in the plasma chamber and not towards the HF window which will then have a lifetime will be unlimited. It is also possible to use so-called "overdense" plasmas (in English) where the plasma frequency is greater than the microwave frequency. The use of "over-dense" plasmas makes it possible advantageously to increase the electronic density and therefore to increase the efficiency of the system.

The water vapor is injected substantially along the axis AA 'vertical in the plane of the sheet by the injection means.

The orientation of the magnets 3, 4, 5 and 6 is such that, at the point where the water vapor and the microwaves (between the two magnets 4 and 5) are injected, two identical polarities face each other: thus the two magnets 4 and 5 have the same north polarity (of course, the invention also applies with the same polarity south). Conversely, at the hydrogen recovery point (between the two magnets 3 and 6), the opposite polarities are of opposite signs: thus, the magnet 3 has a north polarity and the magnet 6 a a south polarity. In addition, the polarities of the magnets located on the one hand on the side of the injection of water vapor (magnet 4 having a north polarity) and on the other hand on the hydrogen recovery side (magnet 6 having a south polarity), are of opposite signs. As a result, the magnetic field lines 12 are curved, thus making it possible to recover the non-dissociated or ionized water vapor on the water condenser 9 placed near the magnet 5, in a straight line with respect to the axis AA 'water vapor injection. If the magnetic field lines 12 were not curved, there would be no possibility to recycle the undissociated water. Indeed, non-dissociated water molecules are not guided by the magnetic field lines and preferentially in a straight line with respect to the injection of water vapor. In other words, in a simple axisymmetric mirror, the undissociated water as well as the hydrogen and dissociated oxygen should be recovered in the same place and at the same time, which is difficult to achieve.

The tubular water condenser 9 is placed directly in the chamber 2 in which there is a pressure of the order of 10.sup.- ³ mbar.Figure 2, which represents a phase diagram of the water, shows that at the pressure considered The non-dissociated condensate is always in the form of steam at temperatures above 200 K, which is the case in the plasma chamber 2. This condenser 9 is here a vertical pipe in which a pressure gradient of 10 ^{° is established. 3} mbar to 10 ^-2 mbar and 1 bar). Thus, the water, which goes from the vapor form to the liquid form, flows along the vertical pipe 9 by gravity and is advantageously recycled via the recycling pump 10. However, if the recycling pipe 9 is short, the pressure gradient in the tubing can remain low and the water can be fed back into the device 1 directly in the vapor phase.

The ions created are guided along the field lines 12.

At this stage, the device 1 according to the invention must separate the different products formed in order to extract the hydrogen. For this purpose, it is advantageous to use the phase diagrams of the hydrogen and oxygen elements for the low temperatures as represented in FIG. operating pressure of the chamber 2 considered being less than 5 × 10 ^-3 mbar, it is noted that for a temperature between 6K and 4OK (preferably between 5K and 30K), it is possible to cryopreset oxygen while keeping Thus, according to the invention, one or more cooled plates are inserted at the end of the plasma device 1 at a temperature such that the two elements composing the plasma (oxygen and hydrogen) are in different phases. (Gaseous hydrogen and solid oxygen) The temperature is determined by calculating the hydrogen partial pressures from the initial plasma density which is correlated with the microwave frequency injected.The temperature is also determined to minimize the power consumption. cryo-refrigerator: it will be preferentially close to 3OK.

In application of the foregoing, the oxygen condenser 8 is a solid or open cryo-panel (or cryogenic panel) arranged at the end of the magnetic field lines 12. Thus, the plasma which follows these lines of field thanks to its electroneutrality, arrives near the wall 8 whose temperature is around 20-30K for example. All particles are trapped except hydrogen will remain in the gas phase. It will be noted that the various components resulting from the dissociation of water are essentially; H ₂ , O ₂ , OH, H, O, O ⁺ , H ⁺ , H ₂ ⁺ , O ₂ ⁺ , OH ^" All the ionized elements neutralize each other before touching a wall (a wall of a cryopanel or another wall), while the neutral elements recombine to give stable elements: H ₂ , O ₂ , H ₂ O.

A condenser 7 with cold walls (at a temperature below 5K and different from the condenser temperature 8) such as a cryo-solid or perforated panel is placed outside the magnetic field lines for cryocondensing hydrogen. Thus, hydrogen and oxygen are attached to independent cold walls (respectively the condenser 7 to recover the hydrogen and the condenser 8 to freeze the oxygen without freezing the hydrogen) that it will be sufficient to heat independently one of the another to separately recover hydrogen and oxygen either in liquid form or in gaseous form. The pump 13 for pumping hydrogen gas is located outside the field lines 12 near the end of the field lines 12

Thus, at the level of the field lines 12, the condenser 8 whose temperature is of the order of 20-30K traps the oxygen of the plasma. At this temperature, the hydrogen is not trapped, remains gaseous and can therefore be pumped via the pumping means 13.

It can therefore be seen that two types of means for recovering hydrogen from the dissociation can be used interchangeably, the oxygen being trapped by said cryogenic condenser 8: a cryogenic condenser 7 and / or pumping means 13.

Note that, according to the grid shown in Figure 3, a tile corresponds substantially to 1 cm; therefore, the width of the microwave injection window is of the order of 2 cm (this scale is valid for all of Figures 3 to 15). However, it should be noted that one would not depart from the scope of the invention by adopting different dimensions, especially higher. The dimensions of each magnet have been calculated to obtain resonance zones in the plasma chamber, where the electrons take enough energy to dissociate the water molecules and at least partially ionize the dissociation products. Thus, for the 2.45 GHz frequency, the magnets are typically 5.4 cm wide and 6.5 cm long (this is an example embodiment, but of course there may be other combinations at a given frequency). The height is, in turn, defined by the skilled person according to the available space and its needs. It can go, indeed from a few centimeters to several meters.

Figure 4 is a variant of the previous figure (the means in common between the devices 1 and 20 have the same reference numbers and perform the same functions). The device 20 according to this second embodiment differs from the device 1 of FIG. 3 in that it comprises a non-dissociated water condenser 16, said condenser 16 being cooled, for example with liquid nitrogen (at 77K ) in order to fix the water in the form of ice (to save electrical energy, it is also possible to recycle liquid water at some ⁰ C). The condenser 16 is arranged near the magnet 5, in a straight line with respect to the axis AA 'of steam injection. In this case, a person skilled in the art will be able to carry out a heating cycle: without stopping the injection of the microwaves, but by stopping the external supply of water vapor, a progressive heating of the condenser will again create steam. water which can then be returned to the chamber 2 via recycling means 17: this water vapor can be dissociated and ionized. Advantageously, two water condensers may be installed in the enclosure so that a condenser will be heated at low temperature to trap the water, while the other will be in the warming phase to release water vapor .

The device 20 according to the invention comprises a separation chamber 14 to avoid sending water in the form of steam anywhere in the chamber 2 (and in particular on the walls). This separation chamber is particularly useful when the water vapor is not introduced into the plasma chamber 2 in the form of a directional jet.

FIG. 5 is a simplified representation of a device 100 for producing electron cyclotron resonance hydrogen according to a third embodiment of the invention.

The device 100 comprises:

a vacuum sealed chamber with plasma;

- Four bars of permanent magnets 103, 104, 105 and 106 placed outside the chamber 102 (the bars typically have a height of between a few centimeters and 1 m, for example 270 mm according to the embodiment described here);

a condenser 108 for trapping oxygen;

a pump 120 for pumping hydrogen gas; a condenser 1 16 of undissociated water and means 1 17 recycling;

means for injecting water vapor into the chamber 102 and means for propagating high-frequency waves inside the chamber 102, said injection and propagation means being illustrated by the arrow 1 1 1 and being located near the magnet 104;

a grid 18 filtering the high frequency waves;

- Means 1 19 for protection against trapping water outside the chamber 102. The chamber 102 is under vacuum, the vacuum being performed by means of pumping ad hoc.

The magnetic structure formed by the four bars 103, 104, 105 and 106 surrounding the chamber 102 produces inside the chamber 102 a magnetic field whose configuration is a magnetic mirror configuration having at least two maxima and a minimum of field magnetic and at least one resonance zone (here a plurality of resonance zones represented by white points 21 located on the field lines 1 12).

An unrepresented microwave generator is placed outside the chamber 102; this generator sends high frequency waves in the chamber 102 via the aforementioned propagation means.

The means for injecting water vapor into the chamber 102 are preferably placed near the microwave generating means. The water is introduced into the plasma chamber 102 in vapor phase.

Thanks to the electron cyclotron resonance principle, at each passage in the vicinity of the resonance zone, the electrons will acquire energy. They will then be able to dissociate the water molecules, and then at least partially ionize the dissociation products. Thanks to the electroneutrality of the plasma, these ions will follow the electrons on the lines 112 of magnetic field. The water vapor is injected substantially along the axis AA 'vertical in the plane of the sheet by the injection means. The device 100 according to the invention comprises a separation chamber 119 making it possible to avoid sending the water in the form of steam anywhere in the chamber 102 (and in particular on the walls). This separation chamber is particularly useful when the water vapor is not introduced into the plasma chamber 102 in the form of a directional jet.

The condenser 1 16 of undissociated water is cooled, for example with liquid nitrogen (at 77K) so as to fix the water in the form of ice. The condenser 1 16 is arranged near the magnet 105, in a straight line with respect to the axis AA 'of steam injection. It is of course also possible to keep the water in liquid form with a condenser at a few ° C., the latter solution being more economical.

The 4 bars of permanent magnets 103 (south polarity), 104 (north polarity), 105 (north polarity) and 106 (south polarity) are placed in such a way that poles with the same sign face each other. The magnetic inductions of all these magnets are equal in absolute value. The distance between the magnets 104 and 103 being shorter than the distance between the magnets 104 and 106, the magnetic field lines are from 104 to 103. The role of the magnets is to obtain magnetic field lines and to create NCE areas. In an exemplary embodiment for a microwave frequency of 2.45 GHz, the basic section of a magnet bar is close to 5.4 cm × 6.5 cm. The height can vary from a few centimeters to several meters. The water vapor is injected at the magnet 104 in the direction AA 'parallel to the magnetic field lines. It is the same for microwaves. In this way, the water vapor that is not used in the plasma goes directly to the condenser H ₂ O 1 16 to be recycled via the recycling means 1 17. The curvature of the field lines makes it possible not to recover in the same area, undissociated water, hydrogen and oxygen. Because of the differences in the condensing temperature of these elements, there would be a build-up of ice which would greatly reduce the effectiveness of the system until the machine stops. The condenser 108 whose temperature is of the order of 20-30K traps oxygen plasma. This oxygen condenser 108 is for example a cryo-panel (or cryogenic panel) solid or perforated arranged at the end of the magnetic field lines 1 12. At this temperature, the hydrogen is not trapped, remains gaseous and can therefore be pumped via the pump means 120. It is then necessary to carry out regeneration cycles to evacuate the oxygen that accumulates over time on the cold wall of the condenser 108.

It should be noted that the device 100 according to the invention consists of a version of the invention in which the magnetic field lines are strongly curved so that a central part with a quasi-flat field is obtained. This advantageous form allows a good separation of the undissociated water which rapidly leaves the plasma. Figure 5 also shows that the number of zones of resonances increases, which is advantageous for the process of dissociation of molecules and ionization of the formed atoms.

In addition this arrangement allows to place a catalyst on almost the entire length of the machine as will be illustrated in Figure 7.

It will be further noted that there are also magnetic field lines which go from magnet 105 to magnet 106 with also resonance zones. The means 16 for recovering water should preferably not be in a dense plasma zone. For this, the RF grid 1 18 whose mesh will be small in relation to the wavelength of the microwaves injected, allows to obtain a plasma only in the desired area. The mesh is chosen so as to prevent propagation of the microwaves while allowing the water molecules to pass.

Figure 6 is a variant of the previous figure (the means in common between the devices 100 and 200 have the same reference numbers and perform the same functions). The device 200 according to this fourth embodiment differs from the device 100 of FIG. 5 in that it comprises a cryogenic condenser system for trapping hydrogen. This system is here produced in the form of two cold walls 207 and 213, whose temperature is less than 5K, which trap the hydrogen. Here too, the cold-walled condenser 108 for trapping oxygen is located in the magnetic field lines 1 12 while cold walls 207 and 213 for trapping hydrogen are placed outside the magnetic field lines 1 12. It should be noted that the RF grid is not shown in FIG.

FIG. 7 represents a top view of a fifth embodiment of a device 300 according to the invention. The device 300 is identical to the device 200 of FIG. 6 (the means in common between the devices 200 and 300 bear the same reference numbers and perform the same functions) and also comprises a catalyst surface 301 placed in the mirror zone. magnetic, preferably between the resonance zones. This catalyst surface is intended to increase the dissociation efficiency of the water and the ionization of the dissociated elements: it fixes the water molecules to increase the dissociation efficiency of the water by electron impacts of the plasma on this surface .

The catalyst 301 is for example a surface based on TiO ₂ . In view of the fact that the catalyst 301 is placed not far from the plasma, the device according to the invention designed to dissociate the water may advantageously be used, in a first step, for the surface treatment of the catalyst in order to increase its effectiveness: in this case In this case, an argon plasma will be used. This catalyst is placed close to the plasma so as to benefit from a surface treatment in a first phase of use of the machine. Then, the hydrophilic character of this catalyst will regulate the influx of water vapor in the machine. Thus the device can operate either with an undissociated H ₂ O recovery system, or with a catalyst, or with a combination of the two methods of regulating the amount of water in the device.

Figure 8 shows a top view of a sixth embodiment of a device 400 according to the invention. This device 400 differs from the device 200 of FIG. 6 in that it comprises:

four permanent magnets 403, 404, 405 and 406 such that the magnetization of magnet 403 (south pole) is 0.7 times lower than the magnetization of magnet 406 (south pole) which itself has the same magnetization as magnets 404 and 405 (two north poles);

a second cryogenic condenser 108 'for trapping oxygen;

a second cryogenic condenser system for trapping the hydrogen produced in the form of two cold walls 207 'and 213'.

The other means in common between the device 200 according to FIG. 6 and the device 400 according to FIG. 8 bear the same reference numbers.

Thanks to the magnetic structure formed by the four permanent magnets 403 to 406, the field lines 212 are divided into two series 412 and 412 'of magnetic field lines so as to be able alternately to recover hydrogen and oxygen. two different places. For this, it is sufficient to reduce, in absolute value, the magnetization value of the magnet 403 with respect to the magnetization of the magnets 404, 405 and 406. By the magnetization values chosen, the field lines 412 and 412 'will go from the magnet 404 at which water vapor and microwaves are injected respectively to the magnets 406 and 403.

The device 400 thus comprises two recovery chambers 407 and 408. The recovery chamber 408 comprises:

- The two cold walls 207 and 213, whose temperature is less than 5K, which trap the hydrogen. the cold-wall condenser 108 for trapping the located oxygen, said condenser 108 intercepting the series 412 of magnetic field lines while the cold walls 207 and 213 for trapping the hydrogen are placed outside the series 412 of lines magnetic field.

The recovery chamber 407 comprises:

- The two cold walls 207 'and 213', whose temperature is less than 5K, which trap the hydrogen. the cold-wall condenser 108 'for trapping the located oxygen, said condenser 108' intercepting the series 412 'of magnetic field lines while the cold walls 207' and 213 'for trapping the hydrogen are placed out of the series 412 'of magnetic field lines.

These two enclosures 408 and 407 are alternately connected to the plasma chamber 102, for example via a slide valve 414. Thus, while the condensers located at the chamber 407 separately trap the particles, the enclosure 408 is isolated from the plasma chamber 102 to successively regenerate the two condensers: this regeneration process is first of all by raising the temperature of 5K to a temperature of less than 3OK so that the hydrogen passes into the gas phase and can to be pumped, then by raising the temperature to a temperature above 40K to pump the gaseous oxygen. The device 400 according to the invention uses here an example of plasma with 3 branches: the injection of water vapor and microwaves is done in a branch, then the plasma is divided into two branches where are placed the recovery systems of hydrogen and oxygen.

Figure 9 shows a top view of a seventh embodiment of a device 500 according to the invention.

The device 500 comprises:

a sealed chamber 502 under vacuum;

- six bars of permanent magnets 503, 503 ', 504, 505, 506 and 506' placed outside the chamber 502; the magnets 503 (south pole) and 506 (south pole) face each other on either side of the chamber 502; the magnets 504 (north pole) and 505 (north pole) face each other on either side of the chamber 502; the magnets 503 '(south pole) and 504' (south pole) face each other on either side of the chamber 502;

means for injecting water vapor into the chamber 502 and means for propagating high-frequency waves inside the chamber; chamber 502, said injection and propagation means being illustrated by the arrow 51 1 and being located near the magnet 504;

two unrepresented recovery chambers;

a condenser 516 of undissociated water. The chamber 502 is under vacuum, the vacuum being carried out by means of pumping ad hoc.

The magnetic structure formed by the six permanent magnets 503, 503 ', 504, 505, 506 and 506' surrounding the chamber 502 produces inside the chamber 502 a magnetic field whose configuration is a magnetic mirror configuration exhibiting at least two maxima and a minimum of magnetic field and at least one resonance zone (here a plurality of resonance zones represented by white dots 21 located on the field lines 512 and 512 ').

The six permanent magnets 503, 503 ', 504, 505, 506 and 506' are such that the magnetization of the magnets 503 and 503 '(both having a south polarity) is 0.7 times lower than the magnetization of the magnets. magnets 504 and 505 (both having a north polarity) and magnets 506 and 506 '(both having a south polarity).

Thanks to the magnetic structure formed by the six permanent magnets 503, 503 ', 504, 505, 506 and 506', the field lines divide into two series 512 and 512 'of magnetic field lines so as to recover the hydrogen and oxygen in two different places thanks to the cryogenic traps that we will detail later. For this, it suffices to decrease, in absolute value, the magnetization value of the magnets 503 and 503 'with respect to the magnetization of the magnets 505, 504, 506 and 506'. In doing so, the magnetic field lines are guided to the places where the condensers are placed. From the chosen magnetization values, the field lines 512 and 512 'will go from the magnet 504 at which the steam and the microwaves are injected to the magnets 506 and 506'. The first recovery chamber includes: two cold walls 507 and 513, whose temperature is less than 5K, which trap hydrogen;

a cold-wall condenser 508 for trapping the located oxygen, said condenser 508 intercepting the magnetic field line series 512, while the cold trays 507 and 513 for trapping the hydrogen are placed out of the series 512 of magnetic field lines.

The second recovery chamber comprises:

two cold walls 507 'and 513', whose temperature is less than 5K, which trap hydrogen. a cold-wall condenser 508 'for trapping the located oxygen, said condenser 508' intercepting the series 512 'of magnetic field lines while the cold walls 507' and 513 'for trapping the hydrogen are placed out of the 512 'series of magnetic field lines.

Thanks to the electron cyclotron resonance principle, at each passage in the vicinity of the resonance zone, the electrons will acquire energy. They will then be able to dissociate the water molecules, and then at least partially ionize the dissociation products. Thanks to the electroneutrality of the plasma, these ions will follow the electrons on lines 512 and 512 'of magnetic field.

The condenser 516 of undissociated water is cooled, for example with liquid nitrogen (at 77K) so as to fix the water in the form of ice (as already explained above, it is also possible and more economical to recover in liquid form at a few ⁰ C). The condenser 516 is arranged near the magnet 505, in a straight line with respect to the axis AA 'of steam injection. The water vapor is injected at the magnet 504 in the direction AA 'parallel to the magnetic field lines. It is the same for microwaves. In this way, the steam which is not used in the plasma goes directly to the condenser H ₂ O 516 to be recycled through recycling means 517. As in the case of Figure 8, the two recovery chambers may be alternately connected to the plasma chamber 502, for example via a not shown slide valve. Thus, while the condensers located at the level of the first chamber separately capture the particles, the second chamber is isolated from the plasma chamber 502 to regenerate successively the two condensers.

FIG. 10 is a top view of an eighth embodiment of a device 600 according to the invention.

The device 600 comprises: a sealed chamber 602 under vacuum;

- six bars of permanent magnets 603, 603 ', 604, 605, 606 and 606' placed outside the chamber 602; the magnets 603 (south pole) and 606 (south pole) face each other on both sides of the chamber 602; magnets 604 (north pole) and 605 (north pole) face each other on both sides of chamber 602; the magnets 603 '(south pole) and 604' (south pole) face each other on both sides of the chamber 602;

means for injecting water vapor into the chamber 602 and means for propagating high-frequency waves inside the chamber 602, said injection and propagation means being illustrated by the arrow 61 1 and being located near the magnet 604;

two oxygen condensers 608 and 608 'made in the form of cold walls arranged at the ends of the magnetic field lines 612 and 612';

two cold-wall condensers 609 and 610 for the recovery of hydrogen (at a temperature below 5K) located near the end of the field lines 612 'but not intercepting the field lines 612'.

a pump 613 for pumping hydrogen gas located near the end of the field lines 612; a catalyst surface 614 placed in the magnetic mirror zone, preferably between the resonance zones

The chamber 602 is under vacuum, the vacuum being carried out by means of pumping ad hoc (typically a residual vacuum of 0.1 Pa is sufficient). The magnetic structure formed by the six permanent magnets 603,

603 ', 604, 605, 606 and 606' surrounding the chamber 602 produces inside the chamber 602 a magnetic field whose configuration is a magnetic mirror configuration having at least two maxima and a minimum of magnetic field and at least a resonance zone (here a plurality of resonance zones represented by white dots 21 located on the field lines 612 and 612 ').

The six permanent magnets 603, 603 ', 604, 605, 606 and 606' are such that they have the same magnetization and the same dimension.

Thanks to the magnetic structure formed by the six permanent magnets 603, 603 ', 604, 605, 606 and 606', the field lines are divided into two series 612 and 612 'of magnetic field lines so as to recover the hydrogen and oxygen in two different places. By the chosen magnetization values, the field lines 612 and 612 'will go from the magnet 604 at which the water vapor and the microwaves are injected to the magnets 603 and 603' (the lines go from north to the south by the shortest path since all the magnets have the same induction).

Thanks to the electron cyclotron resonance principle, at each passage in the vicinity of the resonance zone, the electrons will acquire energy. They will then be able to dissociate the water molecules, then ionize the dissociation products. Thanks to the electroneutrality of the plasma, these ions will follow the electrons on lines 612 and 612 'of magnetic field.

In the case of the device 600, the hydrogen is recovered in two different ways: Thus, at the level of the field lines 612, the condenser 608 whose temperature is of the order of 20-30K traps the oxygen of the plasma. At this temperature, the hydrogen is not trapped, remains gaseous and can therefore be pumped via the pumping means 613.

At the level of the field lines 612 ', the plasma which follows these lines of field thanks to its electroneutrality, arrives near the wall 608' whose temperature approaches for example the 20-30K. All particles are trapped except hydrogen will remain in the gas phase. The two cold-walled condensers 609 and 610 (at a temperature below 5K and different from the condenser temperature 608 ') are placed outside magnetic field lines for cryocondensing hydrogen. The device 600 does not comprise an undissociated water condenser but additionally comprises a catalyst surface 614 placed in the central magnetic mirror zone, preferably between the resonance zones and arranged in a straight line with respect to the AA axis. 'injection of water vapor. This catalyst surface is intended to increase the dissolving efficiency of the water and the ionization of the dissociated elements: it fixes the water molecules to increase the dissociation efficiency of the water by electronic impacts of the plasma on this surface. It can therefore be assumed that the majority of the water vapor will be dissociated and that an undissociated water recovery condenser is not necessary; the presence of the water recovery condenser, however, improves the efficiency of the device.

The device 600 further comprises means 615 for protection against trapping water outside the chamber 102

FIG. 11 shows a top view of a ninth embodiment of a device 700 according to the invention. The device 700 is substantially identical to the device 500 of FIG. 9 (the means in common between the devices 200 and 300 bear the same reference numbers and perform the same functions); the device 700 differs from the device 500 in that it comprises two identical permanent magnets 704 and 705 (two north poles) in place of the permanent magnets 504 and 505. The magnet 704 is at the level of the steam injection 1. The width of the magnets 704 and 705 has been increased compared to those of the magnets 504 and 505. Therefore, the size of the magnets the resonance zone at the level of the injection 51 1 in the device 700 is greater than that of the device 500.

By virtue of the arrangement, the size and the distance separating the different magnets 503, 506, 704, 705, 503 'and 506', the device 700 according to the invention makes it possible to generate a plasma with 5 branches: the injection of steam from water and microwaves is made in a branch, then the plasma is divided into four branches 712, 712 ', 712 "and 712'" where are placed the recovery systems of hydrogen and oxygen.

There are therefore four hydrogen and oxygen recovery systems each comprising:

- two cold walls (respectively 507 and 513, 507 'and 513', 707 and 713, 707 'and 713') whose temperature is less than 5K, which trap the hydrogen. a cold wall condenser (respectively 508, 508 ', 708, 708') for trapping the located oxygen, said condenser intercepting the series

(respectively 712, 712 ', 712 ", 712'") of magnetic field lines while the cold walls for trapping hydrogen are placed outside the series of magnetic field lines.

Figure 12 shows a top view of a tenth embodiment of a device 800 according to the invention. The 800 device is a complete system that occupies the entire plasma chamber. Microwave injections are multiple, as are hydrogen recovery systems.

The device 800 comprises:

a vacuum chamber 802 under vacuum; - six bars of permanent magnets 803, 803 ', 804, 805, 806 and 806' placed outside the chamber 802 and having the same magnetization and the same dimensions; the magnets 803 (south pole) and 806 (south pole) face each other on both sides of the chamber 602 at one end thereof; the magnets 804 (north pole) and 805 (north pole) face each other on either side of the chamber 902 in the center thereof; the magnets 803 '(south pole) and 804' (south pole) face each other on both sides of the chamber 602 at the other end thereof;

first water vapor injection means in the chamber 802 and high frequency wave propagation means inside the chamber 802, said first injection and propagation means being illustrated by the arrow 81 1 and being located near the magnet 806 ';

second means for injecting water vapor into the chamber 802 and means for propagating high-frequency waves inside the chamber 802, said second injection and propagation means being illustrated by the arrow 81 1 'and being located near the magnet 803';

third means for injecting water vapor into the chamber 802 and means for propagating high-frequency waves inside the chamber 802, said third injection and propagation means being illustrated by the arrow 81 1 "and being located near the magnet 803;

fourth means for injecting water vapor into the chamber 802 and means for propagating high frequency waves inside the chamber 802, said fourth injection and propagation means being illustrated by the arrow 81 1 '"and being located near the magnet 806;

a first oxygen condenser 808 made in the form of cold walls arranged at the ends of the magnetic field lines 812 'and 812 ";

a second oxygen condenser 808 'made in the form of cold walls arranged at the ends of the magnetic field lines 812 and 812' ";

a first pump 813 for pumping the gaseous hydrogen generated near the lines of the end of the field lines

812 "and 812"; a second pump 813 'for pumping hydrogen gas located near the lines of the end of the field lines 812 and 812'";

four catalyst surfaces 814, 814 ', 814 "and 814'" placed in the central zone of the magnetic mirror.

Thanks to the magnetic structure formed by the six permanent magnets 803, 803 ', 804, 805, 806 and 806', the device 800 according to the invention makes it possible to generate a plasma with 6 branches: the injection of water vapor and microwaves are made in the four branches 812, 812 ', 812 "and 812"' at the level, the two branches 812 'and 812 "meeting at the location where the hydrogen and oxygen recovery systems are placed 808 and 813 and the two branches 812 and 812 '"meeting at the location where are placed the hydrogen and oxygen recovery systems 808' and 813 '.

It will be noted that the device 800 does not comprise an undissociated water condenser but comprises four catalyst surfaces 814, 814 ', 814 "and 814'" intended to increase the dissociation efficiency of the water and the ionization of the water. dissociated elements. Note further that the device 800 comprises two non-dissociated water recycling systems (in small amounts by the presence of catalyst surfaces) each using a recycling pump 815 and 815 '.

Of course, the invention is not limited to the embodiment just described.

Thus, if it is desired to treat a larger quantity of water, it is possible to increase the dimensions of the apparatus while making sure to have resonance zones in the plasma chamber.

It is also possible to use coils (superconducting or not) of magnetic field to create more intense fields.

Although the invention has been more particularly described for a resonance frequency at 2.45 GHz, it is of course possible to use larger microwave frequencies. As we have also noted, for some applications and / or more efficiency of the device, it is quite possible to multiply the number of branches of the plasma. In this way, it is possible to have a device according to the invention comprising: either several systems for recovering hydrogen (in the gas phase or not) and oxygen;

- several water recovery systems;

- or several catalysts;

- or several injection systems (microwaves and / or water vapor); these systems can be used in combination with each other.

Claims

1. Apparatus (1) for producing hydrogen from an electron cyclotron resonance plasma comprising: - a sealed chamber (2) under vacuum for containing a plasma,

means (1 1) for injecting water vapor into said chamber (2),

means (1 1) for injecting a high-frequency wave into said chamber (2),

a magnetic structure (3, 4, 5, 6) for generating a magnetic field in said chamber (2) and generating a plasma ply along the magnetic field lines (12), the module of said magnetic field having a mirror configuration magnetic device with at least one electron cyclotron resonance zone (21) for at least partially dissociating the water molecules introduced in the vapor phase and for at least partially ionizing the products of the dissociation, said device (1) being characterized in that it comprises: at least one cryogenic condenser (8), placed in said sealed chamber (2), for freezing the oxygen resulting from the dissociation without freezing the hydrogen resulting from the dissociation,

means (7, 13) for recovering the hydrogen resulting from the dissociation, the oxygen being trapped by said cryogenic condenser (8).

2. Device (1) according to the preceding claim characterized in that it comprises means (9) for recovering non-dissociated water, the field lines generated by said magnetic structure being curved with respect to the axis injection of water vapor, said means (9) for recovering undissociated water being substantially arranged along the axis (AA ') of injection of water vapor.

3. Device (1) according to claim 2 characterized in that said means (9) for non-dissociated water recovery comprises a second chamber (9) connected to said plasma chamber.

4. Device (20) according to claim 2 characterized in that said non-dissociated water recovery means are formed by a condenser (16).

5. Device according to one of claims 2 to 4 characterized in that said non-dissociated water recovery means are separated from said plasma chamber by a diaphragm device.

6. Device (1) according to one of claims 2 to 5 characterized in that it comprises at least one system (10) for reinjection of water not dissociated in the vapor phase and issued from said recovery means (9). ) non-dissociated water.

7. Device (100) according to one of claims 2 to 6 characterized in that it comprises a mesh (1 18) having a mesh for stopping the propagation of high frequency waves so that said means (1 16) non-dissociated water recovery are arranged in a substantially non-plasma area.

8. Device (1) according to one of the preceding claims characterized in that said cryogenic condenser (1) for freezing the oxygen from the dissociation without freezing the hydrogen from the dissociation is at a temperature between 6 and 41 K for an average pressure of between 10 ^"3 mbar and 5 × 10 ^-3 mbar in said chamber (2).

9. Device (1) according to one of the preceding claims characterized in that said cryogenic condenser (8) for freezing oxygen is a solid or perforated cryogenic panel.

10. Device (1) according to one of the preceding claims characterized in that said cryogenic condenser (8) for freezing oxygen is arranged to intercept said field lines (12) formed by said magnetic structure (3, 4 , 5, 6).

11. Device according to one of claims 1 to 9, characterized in that said cryogenic condenser for freezing oxygen is a cryogenic panel which surrounds said field lines formed by said magnetic structure.

12. Device according to one of the preceding claims characterized in that it comprises an enclosure capable of recovering oxygen when said cryogenic condenser for freezing oxygen is regenerated by raising the temperature.

13. Device (100) according to one of the preceding claims characterized in that said means (120) for recovering the hydrogen from the dissociation comprise a pump for pumping hydrogen in the gas phase.

14. Device (1) according to one of the preceding claims characterized in that said means (7, 13) for recovering hydrogen from the dissociation comprise at least one cryogenic condenser for freezing hydrogen, said cryogenic condenser being at a temperature below the temperature of said at least one cryogenic condenser for freezing oxygen, said at least one cryogenic condenser for oxygen freezing being arranged to trap oxygen before said at least one cryogenic condenser for freeze hydrogen does not trap hydrogen.

15. Device according to the preceding claim characterized in that it comprises: a cryogenic condenser for freezing the hydrogen that can be regenerated by raising the temperature;

an enclosure capable of recovering hydrogen when said cryogenic condenser for freezing hydrogen is regenerated by raising the temperature.

16. Device (400) according to claim 15 characterized in that it comprises:

a first enclosure (408) including: a first cryogenic condenser (108) for freezing oxygen;

A first cryogenic condenser (207, 213) for freezing hydrogen;

a second enclosure (407) including: a second cryogenic condenser (108 ') for freezing oxygen;

A second cryogenic condenser (207 ', 213') for freezing hydrogen; each of said first and second chambers (408, 407) being capable of recovering oxygen and hydrogen independently of one another by regeneration, said regeneration being done by gradually raising the temperature so that the hydrogen passes from first in the gas phase and is recovered and the oxygen then goes into the gas phase and is recovered.

17. Device according to one of claims 14 to 16 characterized in that said at least one cryogenic condenser for freezing hydrogen comprises at least one solid or perforated cryogenic panel.

18. Device according to one of claims 14 to 17 characterized in that it comprises a polarized mesh placed forward, relative to the plasma, said at least one cryogenic condenser to freeze hydrogen and / or said at least a cryogenic condenser to freeze oxygen.

19. Device according to one of claims 14 to 17 characterized in that said at least one cryogenic condenser for freezing hydrogen and / or said at least one cryogenic condenser for freezing oxygen are capable of being polarized negatively to repel the electrons to the plasma.

20. Device (1) according to one of the preceding claims characterized in that said means (7, 13) for recovering hydrogen from the dissociation are arranged not to intercept said magnetic field lines (12).

21. Device (300) according to one of the preceding claims characterized in that it comprises at least one catalyst surface (301) for fixing the water molecules and increase the dissociation efficiency of the water by electronic impacts of the plasma on said surface.

22. Device (300) according to the preceding claim characterized in that said catalyst surface (301) is placed in the magnetic mirror zone, preferably between the resonance zones.

23. Device (1) according to one of the preceding claims characterized in that said magnetic structure comprises permanent magnets (3, 4, 5, 6).

24. Device (1) according to claim 23, characterized in that the magnetic structure comprises permanent magnets (4, 5) whose poles which face each other in the zone of injection of the water vapor are likewise nature.

25. Device according to one of claims 23 to 24 characterized in that the magnetic structure comprises permanent magnets whose poles facing each other in the hydrogen recovery zone are in the same direction, the magnetization values. these magnets being either identical or different.

26. Device according to one of claims 23 to 24 characterized in that the magnetic structure comprises permanent magnets whose poles facing each other, in the hydrogen recovery zone are of opposite direction.

27. Device according to one of claims 23 to 26 characterized in that the permanent magnet located in the steam injection zone is of the same polarity as the magnet located in the recovery zone of the hydrogen.

28. Device according to one of claims 23 to 27 characterized in that the magnetic structure comprises permanent magnets of different sizes and having either the same magnetization or different magnetizations.

29. Device according to one of the preceding claims characterized in that the magnetic structure comprises coils at room temperature and / or superconducting coils at low or high critical temperature, said low or high Tc.

30. Device according to one of the preceding claims characterized in that the input window of said means for propagating a high-frequency wave inside said chamber is placed in a magnetic field whose module is greater to the module of the resonance magnetic field so that the plasma diffuses towards the chamber and thus avoid impacts of the plasma on said window.

31. Device according to one of the preceding claims characterized in that the mirror ratio between the magnetic field maxima of said magnetic mirror and the minimum magnetic field of said magnetic mirror is strictly greater than 1 and preferably greater than 3.