Patent Application
20110262314
The present invention relates to a device for producing hydrogen from electron cyclotron resonance plasma.
Today hydrogen (H2) appears to be an energy vector of great interest, which is called to take on more and more importance and which may, eventually, advantageously be substituted for petroleum and fossil fuels, whose reserves will significantly decrease in the decades to come. In this perspective, it is necessary to develop effective methods to produce hydrogen.
Admittedly, many methods for producing hydrogen from various sources have been described, but a number of these methods have turned out to be unsuitable with regard to the limitation of greenhouse gases.
A first technique consists of using water vapor reforming. This is a technique for transforming 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:
CH4+H2O→CO+3H2
CO+H2O→CO2+H2
the overall result being
CH4+2H2O→CO2+4H2
One of the main problems with this synthesis route is that it produces, as by-products, significant quantities of CO2-type greenhouse gases.
A second method consists of using a partial oxidation technique: This is an exothermal technique, generally without oxidation catalyst, for products such as natural gas, heavy oil residues and coal. The production of synthesis gas is given by the reaction:
CnHm+(n/2)O2→nCO+(m/2)H2
The conversion of carbon monoxide is given by the reaction:
nCO+nH2O→nCO2+nH2
As with reforming, this technique produces a significant quantity of carbon dioxide.
Mention may also be made of a third technique using the direct thermal decomposition of water; such a technique would necessitate extremely high temperatures on the order of 3000 to 4000 K (the use of a catalyst enables this temperature to be reduced, which would, however, remain very high, approaching 1400 K). This production technique is considered by utilizing high-temperature nuclear reactors cooled by a gaseous coolant such as helium (the case of HTR “High Temperature Reactor” type, fourth generation reactors). By virtue of its principle, this technique is connected to uranium production. The other disadvantage is that using this method for producing small amounts of hydrogen is unthinkable.
A fourth pathway consists of carrying out water electrolysis: this is a technique of dissociating water by the passage of an electric current according to the reaction:
This reaction, in which the enthalpy is ΔH=285 kJ·mol−1 (at 298K and 1 bar) is carried out according to the following method: An electrolyte cell is constituted of two electrodes, an anode and a cathode, connected to a direct current generator. The electrodes are immersed in an electrolyte used as a electrical conductor. In general, this electrolyte is an acid or basic aqueous solution, a polymeric proton exchange membrane (H+) or an oxygen ion conductive membrane (O2−).
However, this technique poses certain difficulties; thus the electrodes corrode over time. In addition, such a method necessitates the ongoing adjustment of concentrations and the use of membranes that are either fragile for organic membranes, or have a low yield for mineral membranes.
A fifth solution consists of water decomposition by thermochemical cycle (TCC): This method uses a series of chemical reactions. One 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 hydroiodic acid 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 Fe304 and HBr in the case of the UT-3 cycle.
A sixth pathway considered is the biomass: Obtained by the photosynthesis of carbon dioxide and water, it uses solar energy to produce C6H9O4 molecules. Then there is a thermochemical treatment according to the reaction:
C6H9O4+2H2O+880 kJ→6CO+13/2H2
Gasification to water vapor around 900° C. then produces synthesis gas (CO+H20). A hydrogen supplement is then obtained by the “gas shift” reaction.
6CO+6H2O→6CO2+6H2
Again, the main disadvantage of this technique resides in its production of carbon dioxide.
A seventh technique consists of carrying out photoelectrolysis of water: This is a process that uses the dissociation of the water molecule by an electric current produced by illuminating a semiconductor photocatalyst (Ti02, AsGa).
This process does not produce greenhouse gas but has relatively a low conversion efficiency.
Another method to produce hydrogen gas by microwave plasma is proposed in document WO2006/123883. This method uses the dissociation of gaseous molecules by electron impact. The method disclosed consists of injecting microwave power into a dielectric tube containing an H20 or CH4 type gas or vapor under reduced pressure (50-300 torr). This microwave power causes the ionization and/or dissociation of gas by thus releasing hydrogen (initiating microwave plasma). At the end of the tube, a separator in a palladium type material separates the hydrogen by gaseous diffusion.
Another method to produce hydrogen from water molecules is described in document WO2005/005009. The method disclosed consists of placing water molecules in an electromagnetic field to excite the molecules by thermal agitation until their excitation energy exceeds the bond energy of the H and O atoms composing the water molecule.
Another method of producing hydrogen by injecting water vapor in plasma is described in document US2004/0265137. This patent describes a method of obtaining hydrogen from vapor dissociated in plasma. The document notably mentions the use of electron cyclotron resonance (ECR) to produce said plasma. With relation to the hydrogen production methods previously cited, the use of an ECR plasma machine presents many advantages:
However, despite the advantages mentioned above, a major problem with a plasma machine that breaks, by electron impact, water molecule bonds is the separation of the products formed.
Inserting a dielectric is a possible solution. However, this method presents the disadvantage of using rare and costly compounds.
In this context, the object of the present invention is to provide a device for producing hydrogen from water with electron cyclotron resonance plasma not necessarily requiring significant magnetic fields and enabling effective dissociation of the water molecules and simple separation of the products formed.
For this purpose, the invention proposes a device for producing hydrogen from electron cyclotron resonance plasma comprising:
Sealed vacuum chamber is understood to refer to a chamber in which a working pressure of less than or equal to 5.10−3 mbar exists, said working pressure substantially corresponding to the partial pressure of water vapor injected into the chamber.
Thanks to the invention, hydrogen is produced from water vapor. The device according to the invention is based on the combined use of electron cyclotron resonance plasma and at least one selective cryogenic condenser. This non-C02 emitting device does not use electrodes, membranes or high temperatures.
Thanks to the principle of electron cyclotron resonance, at every 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 ionize, at least partially, the products of dissociation. Thanks to the electroneutrality of plasma, these ions will follow the electrons along the magnetic field lines.
The device according to the invention enables work to continue for several months without interruption or maintenance. The device may, depending on its dimensions, have a plasma volume ranging from some cm3 to several liters, or even m3.
By observing the phase diagrams of the hydrogen and oxygen elements for the low temperatures represented in
It will be noted that, although an electromagnetic field is used, the device according to the invention does not use the water molecule thermal agitation method, but breaks the atomic bonds by collisions with plasma electrons.
According to a particularly advantageous embodiment of the invention, said chamber comprises means to recover the non-dissociated water, the field lines generated by said magnetic structure being curved with relation to the axis of injection of the water vapor, said non-dissociated water recovery means being substantially arranged along the axis of injection of the water vapor.
This advantageous embodiment enables the problem of recovering water molecules not dissociated by plasma electrons to be resolved. In fact, the ionization and dissociation of water molecules is never complete; consequently, a considerable quantity of water molecules remain present. Obviously, it is of interest to recover these non-dissociated water molecules, for example to recycle them by returning them to the chamber in vapor form. If the magnetic field lines were not curved, it would not be possible to recycle the non-dissociated water. Indeed, the non-dissociated water molecules are not guided by the magnetic field lines and preferentially go in a straight line with relation to the water vapor injection nozzle. In other words, in a simple axisymmetric mirror, the non-dissociated water as well as the dissociated hydrogen and oxygen should be recovered at the same place and at the same time, which is difficult to carry out.
According to this advantageous embodiment, the magnetic field lines are curved such that it is then possible to perform, at the same time, non-dissociated water recycling, hydrogen and oxygen separation, hydrogen recovery and oxygen recovery operations. The curved magnetic field lines thus enable the non-dissociated and non-ionized water vapor, for example on a condenser placed in a straight line with relation to the water vapor injection, to be recovered.
The device according to the invention may also present one or more of the characteristics below, considered individually or according to all technically possible combinations:
Each of said first and second enclosures being able to recover oxygen and hydrogen independently from each other by regeneration, said regeneration is done by progressive increase in the temperature so that the hydrogen first passes in gaseous phase and is recovered and the oxygen then passes into gaseous phase and is recovered.
Other characteristics and advantages of the invention will clearly emerge from the description given below, for indicative and in no way limiting purposes, with reference to the attached figures, among which:
In all figures, common elements bear the same reference numbers.
Chamber 2 is under vacuum, the vacuum being achieved by pumping means. In order to have the fewest impurities possible in chamber 2, a residual vacuum of 10−4 mbar minimum is necessary. However, this vacuum (typically up to 10−5 mbar) may be lowered further to have even fewer impurities in chamber 2. During the operation of device 1 (i.e., after injection of water vapor in the chamber), the working pressure of chamber 2 is typically less than or equal to 5.10−3 mbar, this pressure being connected to the partial pressure of water vapor injected into chamber 2.
The magnetic structure formed by the four bars 3, 4, 5, and surrounding chamber 2 produces inside chamber 2 a magnetic field whose configuration is a magnetic mirror configuration presenting at least two magnetic field maxima and one magnetic field minimum and at least one resonance zone (here a plurality of resonance zones represented by white dots 21 located on field lines 12). It is a structure known as minimum B: The plasma electrons are confined in magnetic well.
In a magnetized plasma device such as device 1, the electrons are well confined, particularly those that have a high perpendicular velocity with relation to the magnetic field lines. When microwaves are injected into the plasma, they tend to propagate through the plasma up to the resonance zone. In fact, the energy transfer of the injected microwave power to the plasma electrons is produced at a magnetic field location Bres such that the electron cyclotron resonance condition is established, i.e., when there is equality between the high frequency wave HFW pulse and the cyclotron pulse of the electron:
ωHF=ωce=qeBres/me
A microwave generator, not represented, is placed outside chamber 2; this generator injects high-frequency (HF) waves into chamber 2 via the aforementioned propagation means. The frequency range of the microwaves may go from the GHz to a hundred GHz, the most common generator being the magnetron at 2.45 GHz, commonly used for domestic microwave ovens. For a frequency of 2.45 GHz, there is a magnetic resonance field Bres=0.0875 T. However, for miniature hydrogen production devices (for embedded systems, for example), power transistors may also be used as HF generators. In fact, field effect transistors capable of delivering approximately 60 W at 14.5 GHz now exist.
The means for injecting water vapor into chamber 2 are preferentially placed near the microwave generator means (however, another location may also be chosen for reasons of convenience). The water is introduced in plasma chamber 2 in vapor phase. A simple means to obtain this vapor phase is to depress a water reservoir to some dozen mbar.
Thanks to the principle of electron cyclotron resonance, at every 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 products of dissociation. The electrons follow the magnetic field lines thanks to Laplace's law; thanks to the electroneutrality of plasma, these ions will follow the electrons along magnetic field lines 12.
The best water dissociation rates being obtained for working pressures of less than 5.10−3 mbar, this value is considered to be a maximum working pressure in enclosure 2, all the more so as the electrons would not be magnetically guided if this pressure is increased beyond 5.10−3 mbar.
In the case of interest to us, i.e., the production of hydrogen from water vapor, only the electron population having some dozens eV is useful. At the working pressure under consideration, the energy distribution of electrons goes from some eV to some dozen eV, this distribution being sufficiently large to reach the desired ionization objective.
Advantageously, the high-frequency wave entrance window (represented by the end of arrow 11) is placed in a strong magnetic field zone. In this way, the plasma will diffuse in the plasma chamber and not towards the HF window that will then have an unlimited lifetime. Using “overdense” plasmas, where the plasma frequency is greater than the microwave frequency, is also possible. The use of “overdense” plasmas enables the electronic density to be advantageously increased and thus the system efficiency to be increased.
Water vapor is injected substantially following the vertical AA′ axis in the plane of the sheet by the injection means.
The orientation of magnets 3, 4, 5 and 6 is such that, at the location where the water vapor and microwaves are injected (between the two magnets 4 and 5), two identical polarities face each other: Thus the two magnets 4 and 5 have a same north polarity (of course, the invention also applies with a same south polarity). Conversely, at the hydrogen recovery location (between the two magnets 3 and 6), the polarities that are facing each other have opposed signs: Thus, magnet 3 has a north polarity and magnet 6 has a south polarity. In addition, the polarities of the magnets located, on the one hand, on the water vapor injection side (magnet 4 having a north polarity) and, on the other hand, on the hydrogen recovery side (magnet 6 having a south polarity) have opposed signs. Consequently, the magnetic field lines 12 are curved, thus enabling the non-dissociated and non-ionized water vapor to be recovered on water condenser 9 placed near magnet 5, in a straight line with relation to the AA′ water vapor injection axis. If the magnetic field lines 12 were not curved, it would not be possible to recycle the non-dissociated water. Indeed, the non-dissociated water molecules are not guided by the magnetic field lines and preferentially go in a straight line with relation to the water vapor injection. In other words, in a simple axisymmetric mirror, the non-dissociated water as well as the dissociated hydrogen and oxygen should be recovered at the same place and at the same time, which is difficult to carry out.
The tubular water condenser 9 is placed directly in enclosure 2 in which a pressure on the order of 10−3 mbar exists.
The ions created are guided along field lines 12.
At this stage, device 1 according to the invention must separate the various products formed so as to extract the hydrogen. To do this, phase diagrams for the hydrogen and oxygen elements are advantageously used for the low temperatures, such as represented in
In application of the previous, oxygen condenser 8 is a solid or openwork cryopanel (or cryogenic panel) arranged at the end of magnetic field lines 12. Thus, the plasma that follows these field lines thanks to its electroneutrality arrives close to wall 8, whose temperature is near, for example, 20-30K. All the particles are thus trapped, except for the hydrogen, which will remain in gaseous phase. It will be noted that the various components coming from the dissociation of water are essentially: H2, 02, OH, H, O, 0+, H+, H2+, 02+, OH−. All the ionized elements cancel each other out before touching a wall (either a cryopanel wall or another wall), while the neutral elements recombine to give stable elements: H2, O2, H20.
A condenser 7 has cold walls (at a temperature of less than 5K and different from the temperature of condenser 8) such that a solid or openwork cryopanel is placed outside of the magnetic field lines to cryocondense hydrogen. Thus, hydrogen and oxygen set on the independent cold walls (respectively, condenser 7 to recover hydrogen and condenser 8 to freeze the oxygen without freezing the hydrogen) such that one or the other wall(s) only has to be heated independently to recover the hydrogen and oxygen separately, either in liquid form or in gaseous form.
Pump 13 for pumping gaseous hydrogen is located outside of field lines 12 near the end of field lines 12.
Thus, at field lines 12, condenser 8, whose temperature is on the order of 20-30K, traps the oxygen from the plasma. At this temperature, the hydrogen is not trapped, remains gaseous and may thus be pumped via pumping means 13.
Thus it is observed that two types of means to recover the hydrogen coming from the dissociation may be used, the oxygen being trapped by said cryogenic condenser 8: A cryogenic condenser 7 and/or pumping means 13.
It will be noted that, according to the grid represented in
In this case, the person skilled in the art will carry out a heating cycle: without stopping the microwave injection, but by stopping the external supply of water vapor, progressive heating of the condenser will again create water vapor that will then be returned to chamber 2 via recycling means 17: This water vapor will thus be dissociated and ionized. Advantageously, two water condensers will be installed in the enclosure such that one condenser will be brought to a low temperature to trap the water, while the other will be in heating phase to release the water vapor.
Device 20 according to the invention comprises a separation enclosure 14 preventing water from being sent in vapor form anywhere in chamber 2 (particularly on the walls). This separation enclosure is particularly useful when the water vapor is not introduced in plasma chamber 2 in the form of a directional jet.
The device 100 comprises:
Chamber 102 is under vacuum, the vacuum being achieved by special pumping means.
The magnetic structure formed by the four bars 103, 104, 105, and 106 surrounding chamber 102 produces inside chamber 102 a magnetic field whose configuration is a magnetic mirror configuration presenting at least two magnetic field maxima and one magnetic field minimum and at least one resonance zone (here a plurality of resonance zones represented by white dots 21 located on field lines 112).
A microwave generator, not represented, is placed outside chamber 102; this generator sends high-frequency (HF) waves into chamber 102 via the aforementioned propagation means.
The means for injecting water vapor inside chamber 102 are preferentially placed near the microwave generator means. The water is introduced in plasma chamber 102 in vapor phase.
Thanks to the principle of electron cyclotron resonance, at every 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 ionize, at least partially, the products of dissociation. Thanks to the electroneutrality of plasma, these ions will follow the electrons along magnetic field lines 112.
The water vapor is injected substantially following the vertical AA′ axis in the plane of the sheet by the injection means. Device 100 according to the invention comprises a separation enclosure 119 preventing water from being sent in vapor form anywhere in chamber 102 (particularly on the walls). This separation enclosure is particularly useful when the water vapor is not introduced in plasma chamber 102 in the form of a directional jet.
The non-dissociated water condenser 116 is cooled, for example with liquid nitrogen (at 77K) so as to set the water in ice form. The condenser 116 is arranged near magnet 105, in a straight line with relation to the water vapor injection axis AA′. Of course, the water may be kept in liquid form with a condenser at some ° C., the latter solution being more economical.
The 4 permanent magnet bars 103 (south polarity), 104 (north polarity), 105 (north polarity) and 106 (south polarity) are placed so that the poles with the same sign face each other. The magnetic inductions of all these magnets are equal in absolute value. The distance between magnets 104 and 103 being shorter than the distance between magnets 104 and 106, the magnetic field lines go from 104 to 103. The role of the magnets is to obtain magnetic field lines and to create ECR zones. In an example of 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 may vary from some centimeters to several meters. The water vapor is injected in the region of magnet 104 in the AA′ direction parallel to the magnetic field lines. The same is true for the microwaves. In this way, the water vapor that is not used in the plasma goes directly to H20 condenser 116 to be recycled via recycling means 117. The curvature of the field lines enables the non-dissociated water, hydrogen and oxygen to not be recovered in a same zone. Because of differences in condensation temperature of these elements, ice would accumulate, which would significantly decrease the effectiveness of the system until the machine is stopped.
Condenser 108, whose temperature is on the order of 20-30K, traps the oxygen from the plasma. Oxygen condenser 108 is, for example, a solid or openwork cryopanel (or cryogenic panel) arranged at the end of magnetic field lines 112. At this temperature, the hydrogen is not trapped, remains gaseous and may thus be pumped via pumping means 120. Regeneration cycles should then be carried out to evacuate the oxygen that accumulates over time on the cold wall of condenser 108.
It will be noted that device 100 according to the invention consists of a version of the invention where the magnetic field lines are significantly curved such that a central part with an almost flat field is obtained. This advantageous form enables good separation of the non-dissociated water that quickly leaves the plasma.
In addition, this disposition enables a catalyst to be placed on practically the entire length of the machine, as will be illustrated in
In addition, it will be noted that there are also magnetic field lines that go from magnet 105 to magnet 106, also with resonance zones. Preferentially, the water recovery means 116 should not be found in a zone of dense plasma. To do this, the HF screen 118, whose mesh will be of a small size with relation to the wavelength of the microwaves injected, enables plasma to be obtained only in the zone desired. The mesh is chosen so as to prevent the propagation of microwaves while allowing water molecules to pass through.
It will be noted that the HF screen is not represented in
Catalyst 301 is, for example, a Ti02-based surface. Considering the fact that catalyst 301 is placed not far from the plasma, the device according to the invention designed to dissociate water may advantageously be used for, first, surface treatment of the catalyst to increase its effectiveness: In this case, argon plasma will be used. This catalyst is placed close to the plasma so as to be able to benefit from a surface treatment in a first utilization phase of the machine. Then, the hydrophilic character of this catalyst will allow the input of water vapor into the machine to be regulated. Thus, the device will operate either with a non-dissociated H20 recovery system, or with a catalyst, or with a combination of the two methods for regulating the quantity of water in the device.
The other means in common between device 200 according to
Thanks to the magnetic structure formed by the four permanent magnets 403 to 406, field lines 212 are divided into two series 412 and 412′ of magnetic field lines so as to be able to alternatively recover hydrogen and oxygen in two different locations. To do this, the magnetization value of magnet 403 only has to be reduced in absolute value with relation to the magnetization of magnets 404, 405 and 406.
By virtue of the magnetization values chosen, field lines 412 and 412′ will go from magnet 404, in the region of which water vapor and microwaves are respectively injected, towards magnets 406 and 403.
Device 400 thus comprises two recovery enclosures 407 and 408.
Recovery enclosure 408 comprises:
These two enclosures 408 and 407 are alternatively connected to plasma chamber 102, for example through a slide valve 414. Thus, while the condensers located in the region of enclosure 407 separately trap the particles, enclosure 408 is insulated from plasma chamber 102 to successively regenerate the two condensers: This regeneration process is first done by elevating the temperature from 5K to a temperature of less than 30K so that the hydrogen passes in gaseous phase and may be pumped, then by elevating the temperature to a temperature greater than 40K to pump the oxygen that has become gaseous.
The device 400 according to the invention here uses an example of plasma with 3 branches: The injection of water vapor and microwaves is done in one branch, then the plasma is divided into two branches where the hydrogen and oxygen recovery systems are placed.
The device 500 comprises:
Chamber 502 is under vacuum, the vacuum being achieved by special pumping means.
The magnetic structure formed by the six permanent magnets 503, 503′, 504, 505, 506 and 506′ surrounding chamber 502 produces inside chamber 502 a magnetic field whose configuration is a magnetic mirror configuration presenting at least two magnetic field maxima and one magnetic field minimum and at least one resonance zone (here a plurality of resonance zones represented by white dots 21 located on field lines 512 and 512′).
The six permanent magnets 503, 503′, 504, 505, 506 and 506′ are such that the magnetization of magnets 503 and 503′ (both having a south polarity) is 0.7 times weaker than the magnetization of 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 are divided into two series 512 and 512′ of magnetic field lines so as to recover the hydrogen and oxygen in two different locations thanks to the cryogenic traps that we will describe subsequently. To do this, the magnetization value of magnets 503 and 503′ only has to be reduced in absolute value with relation to the magnetization of magnets 505, 504, 506 and 506′. In so doing, the magnetic field lines are guided to the locations where the condensers have been placed. By virtue of the magnetization values chosen, field lines 512 and 512′ will go from magnet 504, in the region of which water vapor and microwaves are respectively injected, towards magnets 506 and 506′.
The first recovery enclosure comprises:
The second recovery enclosure comprises:
Thanks to the principle of electron cyclotron resonance, at every 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 ionize, at least partially, the products of dissociation. Thanks to the electroneutrality of plasma, these ions will follow the electrons along magnetic field lines 512 and 512′.
The non-dissociated water condenser 516 is cooled, for example with liquid nitrogen (at 77K) so as to set the water in ice form (as already explained previously, it is also possible and more economical to recover in liquid form at some ° C.). The condenser 516 is arranged near magnet 505, in a straight line with relation to the water vapor injection axis AA′. The water vapor is injected in the region of magnet 504 in the AA′ direction parallel to the magnetic field lines. The same is true for the microwaves. In this way, the water vapor that is not used in the plasma directly goes to H20 condenser 516 to be recycled via recycling means 517.
As in the case of
The device 600 comprises:
Chamber 602 is under vacuum, the vacuum being achieved by special pumping means (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 chamber 602 produces inside chamber 602 a magnetic field whose configuration is a magnetic mirror configuration presenting at least two magnetic field maxima and one magnetic field minimum and at least one resonance zone (here a plurality of resonance zones represented by white dots 21 located on field lines 612 and 612′).
The six permanent magnets 603, 603′, 604, 605, 606 and 606′ are such that they present a same magnetization and a same dimension.
Thanks to the magnetic structure formed by the six permanent magnets 603, 603′, 604, 605, 606 and 606′, field lines are divided into two series 612 and 612′ of magnetic field lines so as to recover hydrogen and oxygen in two different locations. By virtue of the magnetization values chosen, field lines 612 and 612′ will go from magnet 604, in the region from which water vapor and microwaves are injected, towards magnets 603 and 603′ (the lines go from north to south by the shortest path inasmuch as all the magnets have the same induction).
Thanks to the principle of electron cyclotron resonance, at every 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 ionize the products of dissociation. Thanks to the electroneutrality of plasma, these ions will follow the electrons along magnetic field lines 612 and 612′.
In the case of device 600, the hydrogen is recovered in two different ways:
Thus, at field lines 612, condenser 608, whose temperature is on the order of 20-30K, traps the oxygen from the plasma. At this temperature, the hydrogen is not trapped, remains gaseous and may thus be pumped via pumping means 613.
In the region of field lines 612′, the plasma that follows these field lines thanks to its electroneutrality arrives close to wall 608′ whose temperature is near, for example, 20-30K. All the particles are thus trapped, except for the hydrogen, which will remain in gaseous phase. The two condensers 609 and 610 with cold walls (at a temperature of less than 5K and different from the temperature of condenser 608′) are placed outside the magnetic field lines to cryocondense the hydrogen.
Device 600 does not comprise a non-dissociated water condenser but comprises a catalyst surface 614 placed in the central zone of the magnetic mirror, preferably between the resonance zones and arranged in a straight line with relation to the water vapor injection axis AA′. This catalyst surface is intended to increase the effectiveness of the water dissociation and the ionization of the dissociated elements: It sets the water molecules to increase the water dissociation yield by electron impacts of the plasma on this surface. Consequently, one may consider that the majority of the water vapor will be dissociated and that a non-dissociated water recovery condenser is not necessary; however, the presence of the water recovery condenser improves the effectiveness of the device.
Device 600 also comprises means 615 to protect against trapping water outside chamber 102.
Device 700 is substantially identical to device 500 of
By virtue of the layout, size and distance separating the different magnets 503, 506, 704, 705, 503′ and 506′, device 700 according to the invention enables a plasma with 5 branches to be generated: The injection of water vapor and microwaves is done in one branch, then the plasma is divided into four branches 712, 712′, 712″ and 712″′ where the hydrogen and oxygen recovery systems are placed.
Thus there are four hydrogen and oxygen recovery systems, each comprising:
The device 800 comprises:
Thanks to the magnetic structure formed by the six permanent magnets 803, 803′, 804, 805, 806 and 806′, device 800 according to the invention enables a plasma with 6 branches to be generated: The water vapor and microwave injection is done in the four branches 812, 812′, 812″ and 812″′ in the region, the two branches 812′ et 812″ meeting at the location where the hydrogen and oxygen recovery systems 808 and 813 are placed and the two branches 812 and 812″ meeting at the location where the hydrogen and oxygen recovery systems 808′ and 813′ are placed.
It will be noted that device 800 does not comprise a non-dissociated water condenser but comprises four catalyst surfaces 814, 814′, 814″ et 814″′ intended to increase the effectiveness of the water dissociation and the ionization of dissociated elements. It will also be noted that device 800 comprises two non-dissociated water recycling systems (in small quantity by virtue of the presence of catalyst surfaces), each utilizing a recycling pump 815 and 815′.
Of course, the invention is not limited to the embodiment that has just been described.
Thus, if one wishes to process a greater quantity of water, it is possible to increase the dimensions of the equipment while ensuring resonance zones in the plasma chamber.
In addition, it is possible to use magnetic field coils (superconducting or not) to create more intense fields.
Even if the invention was more particularly described for a resonance frequency at 2.45 GHz, higher frequency microwaves may, of course, be utilized.
As we have also noted, for some applications and/or for more effectiveness of the device, multiplying the number of plasma branches is quite possible. In this way, it is possible to have a device according to the invention comprising:
| Number | Date | Country | Kind |
|---|---|---|---|
| 0856614 | Sep 2008 | FR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/FR2009/051843 | 9/29/2009 | WO | 00 | 6/9/2011 |
