WO2011050789A2

WO2011050789A2 - Small power plant and method and device for obtaining high purity hydrogen

Info

Publication number: WO2011050789A2
Application number: PCT/DE2010/001274
Authority: WO
Inventors: Anna Huber; Hinrich Lorenzen; Claus-Lüder Mahnken; Siegfried Reck; Sebastian Rosskamp; Dieter Thiesen
Original assignee: Mahnken & Partner Gbr.
Priority date: 2009-11-02
Filing date: 2010-10-29
Publication date: 2011-05-05
Also published as: DE102010049792B4; WO2011050789A3; DE202010018414U1; DE102010049792A1

Abstract

Known small power plants have a reactor for producing pyrolysis gas from, for example, renewable raw materials. The pyrolysis gas produced therein is cooled and scrubbed and the carbon dioxide content thereof is reduced. The obtained combustion gas is then fed to an internal combustion engine for combustion, whereby, for example, electrical energy and combustion heat are made usable. Separating the hydrogen contained in the pyrolysis gas in order to make the hydrogen usable for other uses is also known. Said known small power plants have the disadvantage that the degree of separation and the hydrogen throughput are low. Thus, only a small part of the hydrogen is made usable for further processes. The invention relates to a small power plant (10), wherein a device for separating highly pure hydrogen (22) from the pyrolysis gas has a housing that encloses an interior and has at least one semipermeable partition that is arranged in the housing and separates an area at least partially filled with pyrolysis gas. Thus, high purity hydrogen can be easily separated from the pyrolysis gas. The invention further relates to a method for separating highly pure hydrogen, wherein highly pure hydrogen is separated by means of a semipermeable partition, and to a device and method for separating hydrogen from gas mixtures.

Description

Small power plant and method and apparatus for obtaining high purity hydrogen

Description:

The invention relates to a small power plant according to the preamble of claim 1. Furthermore, the invention relates to a method for obtaining high purity hydrogen from a pyrolysis gas according to the preamble of claim 4. Furthermore, the invention relates to an apparatus and a method for the separation of hydrogen according to the preamble of claim 6 or 9.

Known small power plants of the type mentioned have a reactor for the production of pyrolysis gas from e.g. renewable raw materials. The pyrolysis gas produced therein, which is a gas mixture of, inter alia, hydrogen, carbon monoxide, carbon dioxide and methane, is cooled and washed, and its carbon dioxide content is reduced. The obtained fuel gas is then supplied to an internal combustion engine for combustion, whereby e.g. electrical energy and heat of combustion can be harnessed. It is also known to deposit the hydrogen contained in the pyrolysis gas in order to make it usable for other uses.

To obtain pure or at least mostly pure hydrogen devices or methods are known in which the hydrogen can be separated by means of high pressure and very low temperature from other gases or gas mixtures by liquefaction. This is extremely energy consuming and therefore expensive. In addition, with these devices or methods no high purity hydrogen can be generated because Other gases or foreign substances remain in the then liquid hydrogen phase. The generated or separated hydrogen is thus always at least slightly contaminated or at least not highly pure.

The known small power plants have the disadvantage that the degree of separation and the mass flow rate of hydrogen are low. Thus, only a small part of the hydrogen is used for further processes. Likewise, known processes have the disadvantage that only a small part of the hydrogen can be utilized. Known devices and methods for recovering hydrogen have the disadvantage that they can only be operated with high energy input and no pure or highly pure hydrogen can be generated with it.

On this basis, the object of the invention to provide a small power plant, which makes the hydrogen contained in the pyrolysis gas easily and in large quantities usable. Furthermore, the object of the invention to provide a method which allows the simple separation of high purity hydrogen from pyrolysis gas. In addition, the object of the invention is to provide a device that can easily separate hydrogen from various gas mixtures and without high energy consumption.

A small power plant to solve the above problem has the features of claim 1. Accordingly, a device for separating highly pure hydrogen is arranged in the gas flow between the reactor and the internal combustion engine, wherein the device for separating high-purity hydrogen from the pyrolysis gas enclosing an interior housing with at least one, arranged in the housing, an at least partially filled with pyrolysis gas-separating region having semipermeable partition. Such a device separates the hydrogen from the rest of the pyrolysis gas. Thus, the hydrogen is separated from the rest of the pyrolysis gas, which is used as fuel gas, e.g. the internal combustion engine is fed, for generating electrical energy, e.g. in a fuel cell, usable.

The region filled at least partially with pyrolysis gas preferably has at least one inflow and one outflow and the region, which is usually filled with hydrogen, at least one outflow. This ensures that the pyrolysis gas passed from the reactor into the device can be introduced through the inflow into the region which is at least partially filled with pyrolysis gas. Then, the hydrogen can be deposited by means of the semipermeable partition preferably for the most part from the pyrolysis gas and the preferably largely freed from hydrogen pyrolysis gas are fed as fuel gas from the outflow of the internal combustion engine. The hydrogen can be removed by the outflow of the mostly filled with hydrogen area and used elsewhere.

Preferably, the housing has at least one outer wall of a stainless steel. Stainless steel is not permeable to hydrogen. The outer wall of the housing can thus serve as a collecting container for the separated hydrogen. The hydrogen emerging from the partitions can be collected within the housing and can be conveyed by means of a connected discharge pipe into a storage container. Particularly preferably, the housing has a coating of enamel on an inner side facing the region, which is usually filled with hydrogen. This coating is particularly impermeable to the hydrogen, so that it is collected even more reliable and can not escape.

Preferably, the device for the separation of high-purity hydrogen, a semipermeable partition of ferritic iron or pig iron for the deposition of hydrogen. Pure iron can be used with particular preference, this having an iron content of preferably more than 99.8%. Decisive for the passage of hydrogen through this semipermeable partition is their high iron content and a low content of foreign substances. A partition of ferritic iron or pig iron or pure iron is characterized by the fact that only hydrogen can penetrate them. Other components of the pyrolysis gas, such as methane, carbon dioxide and carbon monoxide are retained by the partition made of ferritic iron or pig iron and even favor the passage of hydrogen. In this way, the deposition of hydrogen is possible with low material costs. The hydrogen atoms are adsorbed on the surface of the semipermeable partition, where there is a high concentration of hydrogen, from the iron with loss of its electron. The resulting hydrogen fumes can, through the lattice structure of the ferritic iron or the pig iron or pure iron favors, migrate through the wall body. Here, the driving force is the concentration gradient of hydrogen. On the surface of the wall body, which has a low hydrogen concentration, the hydrogen recombines with an electron dissolved in the iron to form a hydrogen atom. Thus, only the hydrogen is passed through the wall body, other gases are retained due to their much larger atoms. This effect is particularly pronounced for a semipermeable partition made of pure iron, so that larger amounts of hydrogen can be deposited with such a partition wall. Preferably, the at least one semipermeable partition wall is a tube made of ferritic iron or pig iron or pure iron, through which the pyrolysis gas can be passed. The tubular design of the semipermeable partition allows a simple construction of the device. Furthermore, so that a large surface of the semipermeable partition without high design effort to achieve. In addition, a tubular semipermeable partition is best possible pressure stable against the possibly introduced under pressure pyrolysis gas.

According to a preferred development of the device, several, preferably identical, tubes made of ferritic iron or pig iron or pure iron are arranged within the housing of the device. This arrangement makes the device according to the invention particularly compact. The tubes are used to pass the hydrogen-rich pyrolysis gas, whereas the space outside the tubes, but within the housing, serves for receiving and discharging the high-purity hydrogen. By forming tubes as the surface of the semipermeable partition against the size of the entire device is particularly large. Preferably, the tubes are arranged within the housing at an equal distance from each other and formed largely the same.

A chamber is preferably arranged within the housing for dividing the gas flow into the tubes and for bringing together the gas flow from the tubes. These chambers allow the connection of the device by a respective tube, which opens into the respective chamber and leads out of the respective chamber. Thus, the connection of the device according to the invention is designed particularly simple.

Particularly preferably, means are arranged in front of and / or within the at least one tube for forming the semipermeable partition wall for keeping the flow within the tube turbulent. These means are, for example, from the wall of the tube projecting baffles or the like. The turbulent attitude of the flow causes an increase in the degree of diffusion of hydrogen through the semipermeable partition wall, since the impact probability of the hydrogen molecules is increased at the semipermeable partition by a turbulent flow.

Preferably, the device supplied pyrolysis gas can be supplied hot, in particular heatable. It has been found that the amount of hydrogen passing through the semipermeable partition from the pyrolysis gas is high Temperature is increased under certain conditions. Preferably, this temperature is in the range of 400 ° C. In particular, the pyrolysis gas exiting hot from the reactor for producing pyrolysis gas may be supplied to the apparatus such that its temperature is in the region of 400 ° C. Then no additional heating is necessary. However, it is also conceivable to supply the pyrolysis gas to a temperature close to room temperature.

Furthermore, it has been found to be particularly advantageous if the housing and / or the interior of the housing of the device can be cooled. Cooler temperatures at the side of the semipermeable partition wall facing the inner wall of the housing and thus the region of the housing which is mostly filled with hydrogen favors the recombination of the hydrogen and thus increases the diffusion gradient on the partition wall from the side which is at least partially surrounded by pyrolysis gas to that which is usually surrounded by hydrogen Side of the semipermeable partition.

According to a preferred embodiment of the invention, the tube, preferably all tubes, to form the semipermeable partition wall areas of low wall thickness and areas of high wall thickness. This embodiment of the invention makes it possible in the region of low wall thicknesses to increase the diffusion of the hydrogen through the semipermeable partition wall. The areas of greater wall thickness serve to stabilize the pipe wall against the possibly high internal pressure of the pyrolysis gas.

Preferably, the regions of large wall thickness are formed like a net. Such a net-like support structure makes a tubular semipermeable partition particularly stable. Furthermore, it is advantageous to form the net-like support structure uniformly or approximately uniformly. It is also conceivable to form the areas of low wall thickness at least approximately in the form of rectangles. Preferably, all areas of low wall thickness are the same shape. This, uniform formation of the areas of low wall thickness can be produced by simple means. The arrangement of the rectangular or at least approximately rectangular regions of small wall thickness in the direction of the longitudinal extension of the respective tube allows for a particularly stable reticulated support structure through the regions of greater wall thickness.

According to a preferred embodiment of the invention, the semipermeable partition is magnetically excited, preferably by a magnetic alternating field. A magnetic field, preferably an alternating magnetic field favors the diffusion of hydrogen fumes through the semipermeable partition such that the Hydrogen conversion is significantly increased. This is due to the fact that the hydrogen fumes, as charged particles, experience a force perpendicular to the surface of the semipermeable partition wall due to the magnetic field. Accordingly, the amount of hydrogen deposited is increased by the magnetic excitation.

Particularly preferred is a, preferably each, as a tube, so tubular, formed semipermeable partition surrounded by an electrical conductor, which is acted upon by an electric current, preferably an alternating electrical current. Particularly preferably, the electrical conductor is arranged in the form of a coil around the tubular semipermeable partition wall. Such an arrangement provides an alternating magnetic field which extends substantially in the direction of the longitudinal extent of the tubular semipermeable partition wall. Thus, the hydrogen fumes are excited perpendicular to it, namely radially to the longitudinal axis of the tubular semipermeable partition, for diffusion through the semipermeable partition. This additionally increases the hydrogen separation.

According to a development of the invention, each coil-shaped electrical conductor is designed as a tube, which is preferably flowed through by a fluid which can be used to cool the conductor. This arrangement has the advantage that the conductor is cooled and therefore its electrical conductivity is increased. This strengthens the magnetic field. Further, by the conductor disposed around the tubular semipermeable partition due to its arrangement in a region of high hydrogen combination, namely on the side of the partition in the direction of which the hydrogen is deposited, the area in question is cooled. This promotes the recombination of hydrogen and increases the hydrogen throughput. Preferably, the fluid for cooling is electrically non-conductive. For this example, desalted or distilled water can be used as a fluid.

Between the reactor and the internal combustion engine, a cooler, in particular a cooler and a gas scrubber arranged downstream of the cooler, is preferably arranged. Typically, the pyrolysis gas leaves the reactor at a temperature of about 800 ° C to 1200 ° C. A cooler brings the pyrolysis gas to a lower temperature level, for example to a temperature of 400 ° C. The cooled to this temperature pyrolysis gas is then fed to the device for the separation of hydrogen. Due to the formation of the semipermeable partition of ferritic iron or pig iron or pure iron, the same is not so temperature resistant that the pyrolysis gas with 1200 ° C would be supplied. Accordingly, it is necessary for the device, the pyrolysis gas with a lower To provide temperature. By means of the cooler, the pyrolysis gas can be brought to the desired temperature. If necessary, this temperature can also be in the range of room temperature. Furthermore, by means of a gas scrubber, the flue gas portion of the pyrolysis gas can be reduced to such an extent that the device for separating the hydrogen is not polluted. This significantly reduces the cleaning effort for a small power plant according to the invention. The heat dissipated by the radiator can be fed back to the process at another location, eg for pre-drying the fuel for the pyrolysis reactor. This improves the energy balance of the small power plant according to the invention.

According to a preferred embodiment of the invention, the separated high-purity hydrogen can be stored by means of a compressor in a hydrogen pressure accumulator. Such a hydrogen pressure accumulator allows the storage of large quantities of hydrogen for later use.

A method for achieving the object mentioned has the measures of claim 4. Accordingly, highly pure hydrogen is separated from the pyrolysis gas, preferably before it is fed to an internal combustion engine, by means of a hydrogen separator with a semipermeable partition wall. Thereby, the hydrogen, which is deposited as a high-grade portion of the pyrolysis gas, can be used as high-purity gas for other uses and e.g. not supplied with the remaining pyrolysis gas as the fuel gas of the internal combustion engine. A semipermeable partition, which is preferably permeable only to hydrogen, ensures that only the hydrogen is separated. In this way, it is possible to deposit particularly pure, in particular highly pure, hydrogen. By supplying the pyrolysis gas largely freed from the hydrogen as the fuel gas to the internal combustion engine, it can be burned therein and burned by means of e.g. a further connected generator electrical energy can be generated. The gases present in addition to the hydrogen in the pyrolysis gas, e.g. Methane and carbon monoxide can be burned in the internal combustion engine with much higher efficiency than the hydrogen. Thus, the respective gases for generating energy can be fed to a process with the optimum efficiency.

Preferably, the hydrogen is separated from the pyrolysis gas by means of a semipermeable partition of ferritic iron or of pig iron or pure iron. Such a partition is particularly inexpensive to produce and makes the process economical. A partition made of ferritic iron or pig iron or pure iron is characterized by the fact that only hydrogen can penetrate them, as described above. Other components of the pyrolysis gas, such as methane, carbon dioxide and carbon monoxide are retained by the semipermeable partition of ferritic iron or pig iron or pure iron. In this way, the deposition of hydrogen is possible with low material costs. The hydrogen atoms are adsorbed on the surface of the semipermeable partition, where there is a high concentration of hydrogen, from the iron with loss of its electron. The resulting hydrogen fumes can, through the lattice structure of the ferritic iron or the pig iron or pure iron favors, migrate through the wall body. Here, the driving force is the concentration gradient of hydrogen. On the surface of the wall body, which has a low hydrogen concentration, the hydrogen recombines with an electron dissolved in the iron to form a hydrogen atom. Thus, only the hydrogen is passed through the wall body, other gases are retained due to their much larger atoms.

According to a preferred development of the method, the pyrolysis gas is excited by means of radiation, preferably light in a frequency of the natural resonances of the hydrogen. This excitation promotes the dissociation of hydrogen at the semipermeable partition so that a particularly high hydrogen mass flow rate is achieved.

The process is preferably carried out under elevated pressure and / or under elevated temperature. The pressure is preferably 10 bar, the temperature can be up to 400 ° C, but also in the range of room temperature. These parameters promote the passage of hydrogen through the semipermeable partition, while still retaining other gases in the pyrolysis gas. In particular, a pressure difference between the two surfaces of the semipermeable partition wall increases the hydrogen passage considerably.

Particularly preferably, the semipermeable partition is acted upon to increase the hydrogen passage with an electrical voltage. This electrical voltage is preferably applied as an AC voltage or as a pulsating DC voltage to the semipermeable partition. This procedure significantly increases the hydrogen throughput.

According to a development of the method, the semipermeable partition can be acted upon by a magnetic field, preferably an alternating magnetic field. This also increases the hydrogen throughput and can also be carried out in combination with the measures mentioned above or below.

Preferably, steam is added to the reactor to increase the hydrogen content in the pyrolysis gas. This measure increases the hydrogen output in the pyrolysis reactor while reducing the carbon monoxide yield. The water changes the chemical balance in the reactor. This generates more hydrogen that can be separated.

According to a preferred embodiment of the method, after the separation of the high-purity hydrogen from the pyrolysis gas, in particular from the washed pyrolysis gas, the carbon dioxide content of the largely freed from the hydrogen gas is reduced by means of a gas separator. Thus, the pyrolysis gas is best conditioned as fuel gas for the internal combustion engine, so that it is operated economically. The carbon dioxide recovered from the process can be recycled.

Preferably, the cooled and washed pyrolysis gas is fed to the hydrogen separator by means of a compressor with overpressure. Due to the overpressure of the pyrolysis gas, the concentration of the gases contained therein is significantly increased in relation to the hydrogen-side environment within the hydrogen separator. A larger concentration gradient achieved thereby increases the tendency of the hydrogen to pass through the partition wall. This considerably increases the mass throughput and the economic efficiency of the process.

According to a further preferred development of the method, the high-purity hydrogen is conveyed by means of a compressor into a hydrogen pressure accumulator. The stored hydrogen can then be stored for a long time or fed to another use.

Preferably, the pyrolysis gas is cooled down by means of a cooler and / or scrubber prior to reaching the hydrogen separator and / or cleaned or washed. The cooling of the pyrolysis gas is preferably carried out at a temperature which is particularly favorable for the operation of the hydrogen separator. This may be, for example, 400 ° C, but under certain conditions, but also much less, namely a temperature near room temperature. The fact that the pyrolysis gas is cleaned or washed, the flue gas fractions and soot and other harmful particular solid ingredients of the pyrolysis gas removed from this. Thus, the pyrolysis gas for subsequent processes, especially for the hydrogen, well usable and does not pollute this example.

Furthermore, it is advantageous that, after the separation of the high-purity hydrogen from the pyrolysis gas, in particular from the washed and / or cooled pyrolysis gas by means of a gas separator, the carbon dioxide content of the pyrolysis gas largely freed from the hydrogen is reduced.

An apparatus for solving the above-mentioned problem has the features of claim 6. Accordingly, the device has a semipermeable partition made of ferritic iron or pig iron or pure iron. A partition of ferritic iron or pig iron or pure iron is characterized by the fact that only hydrogen can penetrate them. Here, a high iron content of preferably more than 99.8% is crucial, together with a small proportion of foreign substances. Other constituents of the gas mixture, which may consist of various gases, are retained by such a semi-permeable partition made of ferritic iron or pig iron or pure iron and even favor the passage of the hydrogen. It has been found that the separation of hydrogen from any gas mixture containing hydrogen is possible by means of this device. In this way, the deposition of hydrogen is possible with low material costs. The hydrogen atoms are adsorbed on the surface of the semipermeable partition, where there is a high concentration of hydrogen, from the iron with loss of its electron. The resulting hydrogen fumes can, due to the lattice structure of the ferritic iron or of the pig iron, migrate through the wall body. Here, the driving force is the concentration gradient of hydrogen. On the surface of the wall body, which has a low hydrogen concentration, the hydrogen recombines with an electron dissolved in the iron to form a hydrogen atom. Thus, only the hydrogen is passed through the wall body, other gases of the gas mixture are retained due to their much larger atoms.

According to a preferred development of the invention, the device for separating hydrogen has a housing surrounding an interior space with at least one semipermeable partition made of ferritic iron or pig iron or pure iron, which is arranged in the housing and separates a region which is at least partially filled with a part of the gas mixture. Such a device separates the hydrogen from the rest of the gas mixture. Thus, the hydrogen is separated from the rest of the gas mixture, which For example, as a fuel gas, for example, an internal combustion engine or other use can be fed, for the production of electrical energy, for example in a fuel cell, usable. It is also conceivable to use only the hydrogen or by means of the device to liberate hydrogen gas from impurities by other gases and thus to concentrate, or to make highly pure.

The region filled at least partially with a part of the gas mixture preferably has at least one inflow and outflow and the region, which is usually filled with hydrogen, at least one outflow. This ensures that the gas mixture conducted into the device can be introduced through the inflow into the region filled with at least part of the gas mixture. The hydrogen can then be largely separated from the gas stream by means of the semi-permeable partition wall, and the gas mixture, which is preferably freed from the hydrogen for the most part, can be discharged from the outflow as fuel gas or for another use. The hydrogen can be removed by the outflow of the mostly hydrogen-filled region and used elsewhere, e.g. as fuel for a fuel cell.

Preferably, the housing has at least one outer wall of a stainless steel. Stainless steel is not permeable to hydrogen. The outer wall of the housing can thus serve as a collecting container for the separated hydrogen. The hydrogen emerging from the partitions can be collected within the housing and can be conveyed into a storage container by means of a connected discharge pipe. Particularly preferably, the housing has a coating of enamel on an inner side facing the region, which is usually filled with hydrogen. This coating is particularly impermeable to the hydrogen, so that it is collected even more reliable and lossless. In particular, each area adjacent to the device and thus at least partially filled with high-purity hydrogen is designed in such a way.

Preferably, the at least one semipermeable partition is a tube of ferritic iron or pig iron or pure iron, through which the gas mixture can be passed. The tubular design of the semipermeable partition allows a simple construction of the device. Furthermore, so that a large surface of the semipermeable partition without high design effort to achieve. In addition, a tubular semipermeable partition wall is best possible pressure-stable with respect to a possibly introduced under pressure gas mixture. According to a preferred development of the device, several, preferably identical tubes are arranged within the housing of the device. This arrangement makes the device according to the invention particularly compact. The tubes are used to pass the hydrogen-rich gas mixture, whereas the space outside the tubes, but within the housing, serves to absorb and dissipate the hydrogen. By forming tubes as the surface of the semipermeable partition against the size of the entire device is particularly large. Preferably, the tubes are arranged within the housing at an equal distance from each other or formed largely the same. However, it is also possible to direct the gas mixture outside the pipe or pipes and to discharge the hydrogen within the pipe or pipes.

Preferably, the gas mixture supplied to the device is hot or heated fed, in particular heatable. It has been found that the amount of hydrogen passing through the semipermeable partition from the gas mixture is increased by a high temperature, depending on which constituents the gas mixture contains. Preferably, this temperature is in the range of 400 ° C. In particular, a gas stream which exits hot from a preceding process step can be supplied to the device such that its temperature is in the region of 400 ° C. Then no additional heating is necessary. However, it may also be advantageous, depending on the constituents of the gas mixture, to introduce the gas mixture at room temperature.

Furthermore, it has been found to be particularly advantageous if the housing and / or the interior of the housing of the device can be cooled. Cooler temperatures at the Inner wall of the housing and thus the usually filled with hydrogen region of the housing side facing the semipermeable partition favors the recombination of hydrogen and thus increases the diffusion gradient at the partition of the at least partially surrounded by a part of the gas stream side to the mostly surrounded with hydrogen side of the semipermeable partition.

Particularly preferably, a compressor or a pump is provided, by means of which or the gas mixture of the device can be supplied under elevated pressure. Thus, the concentration of hydrogen in the gas mixture relative to the environment and at least largely filled with hydrogen area is increased. The larger concentration gradient thus increases the throughput of hydrogen. Furthermore, a pump, in particular a vacuum pump, can be provided for the at least largely hydrogen-filled region by means of which the pressure in this region is reduced. This also increases the concentration gradient at the semipermeable partition wall and thus increases the hydrogen throughput. This pump or vacuum pump can also be used to promote the separated hydrogen in pressure tanks. Then only one pump is necessary.

According to a preferred embodiment of the invention, the tube, preferably all tubes, to form the semipermeable partition wall areas of low wall thickness and areas of high wall thickness. This embodiment of the invention makes it possible in the region of low wall thicknesses to increase the diffusion of the hydrogen through the semipermeable partition wall. The areas of greater wall thickness serve to stabilize the pipe wall against the possibly high pressure of the gas mixture.

Preferably, the regions of large wall thickness are formed like a net. Such a net-like support structure makes a tubular semipermeable partition particularly stable. Furthermore, it is advantageous to form the net-like support structure uniformly or approximately uniformly. It is also conceivable to form the areas of low wall thickness at least approximately in the form of rectangles. Preferably, all areas of low wall thickness are the same shape. This, uniform formation of the areas of low wall thickness can be produced by simple means. The arrangement of the rectangular or at least approximately rectangular regions of small wall thickness in the direction of the longitudinal extension of the respective tube allows for a particularly stable reticulated support structure through the regions of greater wall thickness. According to a preferred embodiment of the invention, the semipermeable partition is magnetically excited, preferably by a magnetic alternating field. A magnetic field, preferably an alternating magnetic field, promotes the diffusion of hydrogen fumes through the semipermeable partition such that hydrogen uptake is significantly increased. Accordingly, the amount of hydrogen deposited is increased by the magnetic excitation.

Preferably, the semipermeable partition itself can also be subjected to a voltage, in particular an alternating voltage or a pulsating direct voltage, in order to additionally increase the hydrogen throughput.

According to a development of the invention, each coil-shaped electrical conductor is designed as a tube, which is preferably flowed through by a fluid which can be used to cool the conductor. This arrangement has the advantage that the conductor is cooled and therefore its electrical conductivity is increased. This strengthens the magnetic field. Further, by the cooled conductor disposed by its arrangement around the tubular semipermeable partition in a region of high hydrogen concentration, namely on the side of the semipermeable partition in the direction of which the hydrogen is deposited, the area in question is cooled. This promotes the recombination of hydrogen and increases the hydrogen throughput. Preferably, the cooling fluid is electrically non-conductive, e.g. distilled water.

Furthermore, it is conceivable to irradiate the surface of the semipermeable partition in the resonance frequency of the hydrogen, for example with light in the ultraviolet Color range. This additionally increases the passage of hydrogen, since its dissociation is facilitated by the irradiation.

A method for solving the above-mentioned problem comprises the measures of claim 9. Accordingly, hydrogen is separated from a gas mixture by means of a semipermeable partition, which consists at least largely of ferritic iron or pig iron or pure iron. Here, the proportion of iron within the semipermeable partition is crucial, this is in particular more than 99.8%. Furthermore, a small amount of impurities in the material of the semipermeable partition is necessary. Then only pure hydrogen can penetrate this partition. As a result, the hydrogen, which is deposited as a high-quality fraction of the gas mixture, can be used as a high-purity gas for other uses. A semipermeable partition made of ferritic iron or pig iron or pure iron, which is preferably permeable only to hydrogen, ensures that only the hydrogen is separated. In this way, it is possible to deposit particularly pure, in particular highly pure, hydrogen.

A partition of ferritic iron or pig iron or pure iron is characterized in that only hydrogen can penetrate them, as described above. Other constituents of the gas mixture, such as methane, carbon dioxide and carbon monoxide, but also other gases, are retained by the semipermeable partition made of ferritic iron or pig iron or pure iron. In this way, the deposition of hydrogen is possible with low material costs. The hydrogen atoms are adsorbed on the surface of the semipermeable partition, where there is a high concentration of hydrogen, from the iron with loss of its electron. The resulting hydrogen fumes can, through the lattice structure of the ferritic iron or the pig iron or pure iron favors, migrate through the wall body. Here, the driving force is the concentration gradient of hydrogen. On the surface of the wall body, which has a low hydrogen concentration, the hydrogen recombines with an electron dissolved in the iron to form a hydrogen atom. Thus, only the hydrogen is passed through the wall body, other gases are retained due to their much larger atoms. According to a preferred embodiment of the method, the gas mixture and / or the semipermeable partition or its surface by means of radiation, preferably light in a frequency of natural resonances of hydrogen, excited. This excitation promotes the dissociation of hydrogen at the semipermeable partition so that a particularly high hydrogen mass flow rate is achieved.

The process is preferably carried out under elevated pressure and / or under elevated temperature. The pressure is preferably up to 10 bar, the temperature can be up to 400 ° C, but also in the range of room temperature. These parameters promote the passage of hydrogen through the semi-permeable bulkhead while still retaining other gases in the gas mixture. In particular, a pressure difference between the two surfaces of the semipermeable partition wall increases the hydrogen passage considerably.

The gas mixture is preferably fed to the hydrogen separator by means of a compressor with overpressure. Due to the overpressure of the gas mixture, the concentration of the gases contained therein is significantly increased in relation to the hydrogen-side environment within the hydrogen separator. A larger concentration gradient achieved thereby increases the tendency of the hydrogen to pass through the partition wall. This considerably increases the mass throughput and the economic efficiency of the process. Furthermore, the separated hydrogen for this purpose is preferably sucked with a negative pressure.

According to a further preferred development of the method, the high-purity hydrogen is conveyed by means of a compressor into a hydrogen pressure accumulator. The so stored hydrogen can then be stored for a long time or supplied for further use.

Furthermore, it is advantageous that the gas mixture is heated prior to its supply to the semipermeable partition. This additionally promotes the passage of hydrogen through the semipermeable partition.

Preferred embodiments of the invention will be explained in more detail with reference to the drawing. In this show:

1 shows a small power plant according to the invention with a device for the separation of high-purity hydrogen in a schematic representation,

2 shows the apparatus for the separation of high purity hydrogen of FIG. 1 in a sectional side view,

3 shows the section A-A of the device of Fig. 2,

FIG. 4 shows the detail II of FIG. 2, namely a pipe-shaped semipermeable partition wall of the apparatus of FIGS. 2 and 3 with a tubular conductor surrounding it, FIG.

5 shows an exemplary arrangement with a device according to the invention for the separation of hydrogen,

FIG. 6 shows the device for separating hydrogen from FIG. 5 in a sectional side view, FIG.

Fig. 7 is the section B-B of Fig. 6, as well

Fig. 8 shows the detail VI of Figure 6, namely a tube formed as a semipermeable partition wall of the device of Figs. 6 and 7 with a surrounding tubular conductor.

Fig. 1 shows a small power plant 10 in a schematic representation. In particular, pipelines and the flowing through these pipes streams are only schematically, so with an arrow shown. Reference numerals attached to a license mutatis mutandis designate the flow of material conducted within the respective pipeline as well as the pipeline itself, which is useful for the sake of clarity. Furthermore, with reference to FIGS. 1 to 4, a small power station according to the invention is described as well as the method according to the invention and also the device according to the invention, which is arranged by way of example within the small power station. However, the device according to the invention can also be used, in particular, within other arrangements or alone for the separation or extraction of hydrogen from gas mixtures other than pyrolysis gas, as shown in FIGS. 6 to 8.

The small power plant 10 has a reactor 11, which is a pyrolysis reactor and in which solid fuel 47 can be introduced through a feed hopper 12. The solid fuel, which preferably consists of biologically produced or renewable raw materials, is converted within the reactor 10 by means of a pyrolysis process. The pyrolysis gas which can be generated within the reactor 11 consists inter alia of hydrogen, carbon dioxide, carbon monoxide, methane and small amounts of other gases. The reactor has a reactor housing 13 into which the introduced into the hopper 12 fuel is introduced. Furthermore, the reactor 11 has an ash box 14, in which the ash 55 resulting from the pyrolysis process is collected and disposed of separately.

Within the reactor 11, the fuel 47 is gasified with completion or metered addition of air or oxygen contained in the air. The resulting pyrolysis gas can be fed via a pipe 15 to a gas cooler 16. This gas cooler 16 cools the pyrolysis gas, which is conducted at up to 1200 ° C from the reactor 11, to a temperature of preferably about 400 ° C. After the gas cooler 16, a pipe 17 is arranged, through which the cooled pyrolysis gas can be fed to a gas scrubber 18. The scrubber frees the pyrolysis gas at least as much as possible from solid components and flue gas, such as e.g. Ash and dust and wash it with it. The pyrolysis gas conditioned in this way is referred to below as raw gas.

By means of a pipe 19 connected to the gas scrubber 18, the raw gas can be fed by means of a compressor 20 via a pipe 23 to a device for separating hydrogen, referred to hereafter as a hydrogen switch 22. Within the hydrogen diverter 22, the raw gas can be at least largely freed from hydrogen and can be supplied as fuel gas via a pipe 25 to a gas separator 24. The gas separator 24 separates the carbon dioxide contained in the fuel gas at least mostly from fuel gas. The carbon dioxide can then be supplied via a pipe 43 for other use.

The separated within the hydrogen gate 22 from the raw gas 56 hydrogen can be supplied by means of another compressor 57 a hydrogen pressure tank 58 and stored in this under high pressure.

Through a pipe 44, the fuel gas, which is at least largely freed from carbon dioxide, an internal combustion engine, in the example shown an internal combustion engine 26 can be fed. The fact that the fuel gas was at least largely freed from hydrogen and carbon dioxide, it consists mainly only of methane and carbon monoxide. This gas mixture is particularly suitable for combustion within the internal combustion engine 26. Connected to the internal combustion engine 26 is a generator 27, which can convert the power generated by the internal combustion engine 26 by the combustion of the fuel gas and output via a shaft 28 to the generator 27 into electrical energy ,

By means of a cooling water heat exchanger 45, the excess heat in the internal combustion engine 26 can be supplied to a pre-dryer 46. This pre-dryer 46 serves to reduce the water content of the fuel 47 fed to the reactor 11 via the feed hopper 12.

Furthermore, the internal combustion engine 26 has an exhaust gas heat exchanger 48. By means of this exhaust gas heat exchanger, the heat contained in the exhaust gas 49 of the internal combustion engine 26 can also be supplied to the pre-drier 46. The energy emitted by the combustion engine 26 in the form of heat and not used to generate electrical energy is thus at best completely recycled into the process.

In addition, the small power station 10 has an exhaust gas condenser 50, by means of which the exhaust gas 49 can be freed of residual moisture. The then dry exhaust gas 51 can then be released into the environment. The water 52 flowing out of the exhaust gas condenser 50 can be supplied to a steam generator 53, as a result of which it can be fed to the reactor 11 as water vapor 54. This supply of water vapor 54 in the reactor makes the hydrogen content contained in the pyrolysis 15 controllable within certain limits. A larger amount of supplied water vapor 54 increases the hydrogen content in the pyrolysis gas 15, a smaller amount of supplied water vapor 54 causes the hydrogen content in the pyrolysis gas 15 to decrease. FIGS. 2 and 3 show the hydrogen divider 22 in a sectional side view and in a sectional front view, respectively. The hydrogen diverter 22 is suitable for separating hydrogen from the pyrolysis gas and is explained by way of example in this function. Furthermore, the hydrogen diverter 22 but also for the deposition of hydrogen from any conceivable gas mixture containing hydrogen, can be used.

The hydrogen diverter 22 has an at least approximately cylindrical housing 30 of preferably stainless steel. However, any other material with little or no hydrogen permeability is also usable. Furthermore, any other shape for the housing is conceivable. The housing 30 surrounds an interior 31 of the hydrogen diverter 22, which is delimited by an inner side of the housing 30. The inside of the housing 30 has a coating of enamel, not shown. This coating has a particularly low permeability to hydrogen and makes the housing 30 so hydrogen-penetrable.

Within the housing 30 further partition walls 33 and 39 are arranged, which divide the housing 30 into three chambers. Two of the chambers are arranged at one end of the cylindrical housing 30 and about the same size. These are a separation chamber 34 and a collection chamber 35. A chamber, namely a hydrogen chamber 42 between the partitions 33 and 39, is substantially larger than the two remaining chambers and occupies a major portion of the interior of the housing 30.

Between the partitions 33 and 39, tubes 32 are arranged parallel to the longitudinal extent of the hydrogen diverter 22. The tubes 32 have a same, round cross-section. The tubes 32 are formed of ferritic iron, pig iron or pure iron with an iron content of more than 99.8% and have a wall thickness of preferably less than 0.5 mm. In particular, their wall thickness is only 0.2 mm. The tubes connect through openings 38 in the partitions 33 and 39, the separation chamber 34 and the collection chamber 35 with each other.

The tubes 32 are arranged within the housing 30 in a uniform pattern and in particular run parallel to each other. The tubes 32 are largely equidistant from one another, so that the space within the housing is best filled with tubes 32. The tubes 32 separate as a semipermeable partition made of ferritic iron or pig iron, the separation chamber 34 of the hydrogen chamber 42, ie A region filled at least for the most part with pyrolysis gas or another gas mixture, of an area filled at least for the most part with hydrogen 56.

Within the separation chamber 34 of the hydrogen diverter 22, the raw gas flowing in via the conduit 23 through a feed 36 or any other gas mixture is divided into the tubes 32. Thus, the entire wall surface of all tubes 32 is available for the deposition of hydrogen. The hydrogen is adsorbed by the respective semipermeable partition formed as a tube 32 and exits the semipermeable partition on the side of the hydrogen chamber 42. Consequently, only pure, in particular highly pure hydrogen 56 is present within the hydrogen chamber 42 after the deposition process, which can be supplied to the hydrogen pressure accumulator 58 via a hydrogen discharge 40 and the pipeline 56 by means of the compressor 57. If the hydrogen switch 22 is used within another arrangement, the hydrogen can be withdrawn from the hydrogen removal 40 for further use.

By means of the collection chamber 35, the at least largely freed of hydrogen raw gas is passed through an outlet 37 into the pipe 25 and can be supplied to the further process. If the hydrogen diverter 22 is used for the separation of hydrogen from another gas mixture, it can either be reused from the discharge 37, largely freed from hydrogen part of the gas mixture or disposed of as waste, if only the hydrogen is to be used.

The interior of the hydrogen switch 22, in particular the separation chamber 34 or the supply 36 are designed to be heated. Thus, the introduced into the hydrogen gate raw gas or other gas mixture can be brought to a particularly favorable for the deposition of hydrogen temperature. This is especially at about 400 ° C, but may also be depending on the gas mixture in the range of room temperature of about 20 ° C.

Although not shown in the figures, the hydrogen chamber 42 is coolable. Thus, the hydrogen 56 passing through the semi-permeable partitions, namely the tubes 32, can be cooled, thereby increasing the diffusion gradient for the hydrogen 56 flowing through the tubes 32. This also increases the passage of hydrogen through the pipe 32 formed as a semipermeable partition.

At points of contact 41, of which only a few are shown for reasons of clarity, can be connected to the respective pipe 32 formed as a semipermeable partition an electrical Voltage to be applied. This electrical voltage is preferably an AC voltage, in particular a pulsating DC voltage. For this purpose, it may be useful to electrically isolate the tubes 32 from the remaining hydrogen switch 22, in particular from the partitions 33 and 39, respectively. The electrical current caused by the electrical voltage promotes the passage of hydrogen through the semipermeable partition, respectively through the walls of the tubes 32. The insulation preferably takes place by means of seals arranged between the tubes 32 and the partitions 33 and 39, which have insulating properties. The seals are electrically insulated and gas-tight, especially at high temperatures formed.

The tubes 32 have net-like regions 59 and fields 60 surrounded by the net-like regions 59. In the net-like regions 59, the tubes 23 have a greater wall thickness than in the fields 60. With this design, each tube 32 is stabilized by greater wall thickness in the regions 59, in particular against the internal pressure of the pyrolysis gas. The small wall thickness of the tubes 32 within the fields 60 increases the hydrogen flow rate. As a result, the tubes 32 are stable and yet permeable to a large amount of hydrogen.

Furthermore, the tubes 32, preferably all the tubes 32, are surrounded by spirally arranged conductors 61. The conductors 61 are themselves also tubular and are preferably made of copper or another conductive metal. The conductors 61 are electrically isolated from all other components of the hydrogen pair 22. This is done by gas-tight, in particular high-temperature gas-tight seals, which are not shown. Thus, the conductors 61 can be led out of the housing 30 of the hydrogen diverter 22 without causing the hydrogen diverter 22 to leak.

The conductors 61 are arranged so as to surround the tubes 32 in the form of a coil. The tubular and spiral conductors 61 are electrically contacted and are traversed by an electric current They generate by an approximately congruent arrangement of the coil axis to the central axis of the respective tube 32, a magnetic field which extends at least approximately parallel to the central axis of the respective tube 32. Thus, the hydrogen atoms or hydrogen fumes diffusing in the tube wall in the direction of the outside, namely into the hydrogen chamber 42, are accelerated in their diffusion.

Furthermore, the respective tubular conductor is flowed through by a cooling fluid. As a result, the conductor 61 but also the hydrogen chamber 42 is cooled. This cooling favors the Recombination of the hydrogen atoms in the hydrogen chamber 42 and thus the hydrogen flow rate of the hydrogen diverter 22. In addition, the electrical conductivity of the respective conductor 61 and thus the strength of the magnetic field is increased. Thus, the hydrogen flow rate of the hydrogen gate 22 is further enhanced.

The cooling fluid which flows through the respective conductor 61 is preferably electrically non-conductive. For example, nitrogen or another gas can be used. Water is also conceivable as a cooling fluid, in particular distilled water.

FIG. 5 shows an arrangement with a device according to the invention for the separation of hydrogen, by means of which the method according to the invention is also explained. The arrangement is shown schematically. The device according to the invention within the arrangement is referred to below as the hydrogen switch 62. A gas source 63 contains a gas mixture which also contains hydrogen. The gas mixture is fed by means of a pipe 64 to a pump, namely a compressor 65 and compressed in this compressor 65. The thus compressed gas mixture from the gas source 63 can then be supplied by means of a further conduit 66 of the hydrogen diverter 62.

The gas source 63 is only an example of a supply of a gas mixture which also contains hydrogen. It can e.g. Process gases are cleaned with the hydrogen diverter 62 and their hydrogen content can be utilized. Furthermore, it is conceivable to pass polluted hydrogen through the hydrogen diverter 62 and thus to produce high-purity hydrogen. Each gas mixture may be introduced from the gas source 63 into the hydrogen switch 62.

FIGS. 6 and 7 show the hydrogen divider 62 in a sectional side view and in a sectional front view, respectively. The hydrogen diverter 62 is designed to separate hydrogen from the gas mixture. In this case, the hydrogen diverter 62 can separate hydrogen from any gas mixture which contains hydrogen, namely pure hydrogen.

It is conceivable, for example, for process gases which drop off in other processes to be freed of hydrogen by means of the hydrogen diverter 62. Furthermore, gas mixtures from the chemical industry can be used to obtain their hydrogen content or be purified by electrolysis generated hydrogen. The hydrogen diverter 62 has an at least approximately cylindrical housing 67 of preferably stainless steel. However, any other material with little or no hydrogen permeability is also usable.

But it is conceivable except the cylindrical shape of the housing 67 and any other shape of the housing 67. The housing 67 surrounds an interior 69 of the hydrogen diverter 62, which is bounded by an inner side of the housing 667. The inside 68 of the housing 62 has an enamel coating, not shown. This coating has a particularly low permeability to hydrogen and makes the housing 67 thus not permeable to hydrogen.

Within the housing 67 partition walls 70 and 71 are further arranged, which divide the housing 67 into three chambers. Two of the chambers are arranged at one end of the cylindrical housing 67 and about the same size. These are a separation chamber 72 and a collection chamber 73. A chamber, namely a hydrogen chamber 74 between the partitions 70 and 71, is substantially larger than the two remaining chambers and occupies most of the interior 69 of the housing 67.

Between the partitions 70 and 71, pipes 75 are arranged parallel to the longitudinal extension of the hydrogen diverter 62. The tubes 75 have a same, round cross-section. The tubes 75 are formed of ferritic iron or pig iron and have a wall thickness of preferably less than 0.5 mm. In particular, their wall thickness is only 0.2 mm. The tubes 75 connect through breakthroughs 76 in the partitions 70 and 71, the separation chamber 72 and the collection chamber 73 with each other, in particular gas-tight relative to the hydrogen chamber 74th

The tubes 75 are disposed within the housing 67 in a uniform pattern and in particular parallel to each other. The tubes 75 are at least approximately equidistant from each other, so that the space within the housing 67 is best filled with tubes 75. The tubes 75 separate as a semipermeable partition of ferritic iron or pig iron, the separation chamber 72 and the collection chamber 73 of the hydrogen chamber 74, so at least for the most part filled with the gas mixture from a region at least largely filled with hydrogen area. Within the separation chamber 72 of the hydrogen diverter 62, the gas mixture flowing in via the conduit 66 through a feed 77 is divided into the tubes 75. Thus, the entire wall surface of all tubes 75 is available for the deposition of hydrogen. The hydrogen is adsorbed by the respective semipermeable partition formed as a tube 75 and exits the semipermeable partition on the hydrogen chamber 74 side. Consequently, only pure, in particular highly pure hydrogen is present within the hydrogen chamber 74 after the deposition process, which can be supplied to a hydrogen pressure accumulator 81 via a hydrogen discharge 78 and a pipe 79 by means of a further pump, namely a compressor 80 via a pipe 82. In addition, it is conceivable that the hydrogen from the hydrogen discharge 78 is used directly for further use, for example, is supplied directly to a fuel cell.

The compressor 65 may additionally be used to bring the gas mixture to a higher pressure level. The increased pressure in the at least largely filled with the gas mixture chambers, namely the separation chamber 72, the tubes 72 and the collection chamber 73 increases the concentration gradient of the hydrogen from at least largely filled with the gas mixture side of the semipermeable partition to at least largely filled with hydrogen side That is, the hydrogen chamber 74, and thus increases the hydrogen passage and thus the amount of hydrogen separated.

By means of the collecting chamber 73, the at least largely freed of hydrogen gas mixture is passed through a discharge 83 into a pipe 84. The pipe 84 is controllably closed by a valve unit 85, so that the hydrogen gas for the most part freed gas mixture or gas can not flow unhindered through a pipe 86. Thus, the internal pressure within the gas mixture leading chambers, namely the separation chamber 72, the tubes 75 and the collection chamber 73, by means of the valve unit 85 can be adjusted. The concentration of hydrogen in the gas mixture or the concentration gradient at the semipermeable partition can thus be positively influenced for the function of the device.

In addition, the valve unit serves to direct a part of the already partially hydrogen-free gas mixture via a return line 91 to a valve 92. By means of the valve 92, a portion of the gas mixture recirculated in this way can be returned to the compressor 65 via a pipe 94 in a feed 93. Thus, part of the gas mixture is multiple and controls the hydrogen switch 62 fed. This considerably increases the yield of hydrogen deposition, since the concentration in the region filled at least largely with the gas mixture, namely the separation chamber 72, the tubes 75 and the collection chamber 73, can be kept constant or at least approximately constant.

Furthermore, by means of the compressor 80 in the pipe 79 and thus also in the hydrogen chamber 74 of the hydrogen pair 62, a negative pressure can be generated. This can be done as it were with the injection of hydrogen into the hydrogen pressure accumulator 81, so that no additional pump is needed. Thus, the concentration gradient is also positively influenced on the semipermeable partition wall, namely as a concentration gradient of at least largely filled with the gas mixture area for at least for the most part filled with hydrogen area increased.

Depending on which gas mixture the hydrogen diverter 62 is used for separating hydrogen, the gas mixture largely freed from hydrogen can be led out of the piping 84 or 86 and either reused or disposed of as waste or possibly even released into the environment, if only the hydrogen should be used or the rest of the gas mixture is environmentally friendly.

The interior of the hydrogen diverter 62, in particular the separation chamber 72 and / or the supply 77, are designed to be heatable and / or coolable, although this is not shown in the figures. Thus, the introduced into the hydrogen diverter 62 gas mixture can be brought to a particularly favorable for the deposition of hydrogen temperature. This is in particular at about 400 ° C, but may also be in the range of room temperature of about 20 ° C depending on the gas mixture.

Although not shown in the figures, the hydrogen chamber 74 is coolable. Thus, the hydrogen passing through the semipermeable partitions, namely the tubes 75, can be cooled, thereby increasing the diffusion gradient for hydrogen flowing through the tubes 75. This also enhances the passage of hydrogen through the semipermeable partition formed as tube 75.

At contact points 87, of which only a few are shown for reasons of clarity, an electrical voltage can be applied to the respective tube 75 formed as a semipermeable partition wall along the respective tube 75. This electrical voltage is preferably an AC voltage, in particular a pulsating DC voltage. For this purpose, it may be useful, the tubes 75 from the remaining hydrogen switch 62, in particular of the partitions 70 and 71, to electrically isolate. The electrical current caused by the electrical voltage promotes the passage of hydrogen through the semipermeable partition wall or through the walls of the tubes 75. The insulation preferably takes place by means of seals arranged between the tubes 75 and the partition walls 70 and 71, which have insulating properties. The seals are electrically insulating and gas-tight, especially gas-tight at high temperatures, formed.

Also not shown are such devices by means of which the semipermeable partition wall of the tubes 75 with a radiation, preferably light with a frequency in the region of the natural resonance of the hydrogen, can be excited.

The tubes 75 have net-like regions 88 and fields 89 surrounded by the net-like regions 88. In the net-like regions 88, the tubes 75 have a greater wall thickness than in the fields 89. By this construction, each tube 75 is stabilized by greater wall thickness in the regions 88, in particular against the internal pressure of the gas mixture, which of the hydrogen diverter 62 by means of the compressor 65 is supplied. The small wall thickness of the tubes 75 within the fields 89 increases the hydrogen flow rate. As a result, the tubes 75 are simultaneously stable and yet permeable to a large amount of hydrogen.

Furthermore, the tubes 75, preferably all tubes 75, are surrounded by helically arranged electrical conductors 90. The conductors 90 are themselves also tubular and are preferably made of copper or another electrically conductive metal. The conductors 90 are electrically isolated from all other components of the hydrogen switch 62. This is done by gas density, in particular high-temperature gas-tight seals, which are not shown. Thus, the conductors 90 can be led out of the housing 67 of the hydrogen diverter 62 without causing the hydrogen diverter 62 to leak for the gas mixture.

The conductors 90 are arranged so as to surround the tubes 75 in the form of a coil. The tubular and spiral conductors 90 are electrically contacted and are traversed by an electric current. They generate by an approximately congruent arrangement of the coil axis to the central axis of the respective tube 75, a magnetic field which extends at least approximately parallel to the central axis of the respective tube 75. Thus, in the pipe wall in the direction of the outside, namely in the Hydrogen chamber 74 accelerates into diffusing hydrogen atoms or hydrogen fumes in their diffusion.

Furthermore, the respective tubular conductor 90 is flowed through by a cooling fluid. As a result, the conductor 90 but also the hydrogen chamber 74 is cooled. This cooling promotes the recombination of the hydrogen atoms in the hydrogen chamber 74 and thus the hydrogen flow rate of the hydrogen switch 62. In addition, the electrical conductivity of the respective conductor 90 and thus the strength of the force acting on the respective tube 75 and thus on the semipermeable partition magnetic field is increased. Thus, the hydrogen flow rate of the hydrogen switch 62 is further enhanced.

The cooling fluid which flows through the respective conductor 90 is preferably electrically non-conductive. For example, nitrogen or another gas can be used. Also desalinated water is conceivable as a cooling fluid, but especially distilled water.

Claims

claims:

1. small power plant (10) with a reactor (11) for the production of pyrolysis gas

preferably renewable raw materials and at least one of the pyrolysis gas for generating preferably electrical energy using

Internal combustion engine (26), wherein in the gas flow between the reactor (11) and the internal combustion engine (26) a device (22) for the separation of high-purity hydrogen (56) from the pyrolysis gas is arranged, characterized in that the device for the separation of high-purity hydrogen ( 56) from the pyrolysis gas an inner space (31) surrounding housing (30) with at least one, in the housing (30) arranged at least partially filled with pyrolysis gas region (34) of a filled with mostly hydrogen (56) region (42) having separating semipermeable partition.

2. Small power plant according to claim 1, characterized in that the at least partially filled with pyrolysis gas region (34) has at least one inflow (36) and at least one outlet (37) and the area filled mostly with hydrogen at least one outflow (40).

3. Small power plant according to claim 1 or 2, characterized in that the semipermeable partition wall for the deposition of the high-purity hydrogen (56) consists of ferritic iron and / or pig iron and / or pure iron.

4. A process for obtaining high purity hydrogen from a pyrolysis gas, wherein the pyrolysis gas produced in a reactor (11) preferably one

Internal combustion engine (26) is supplied as fuel gas, thereby

in that highly pure hydrogen is separated from the pyrolysis gas by means of a hydrogen separator (22) with a semipermeable partition wall (32).

5. The method according to claim 4, characterized in that the hydrogen is separated by means of a semipermeable partition wall (32) made of ferritic iron or pig iron from the pyrolysis gas and / or that the pyrolysis gas by means of radiation, preferably light in a frequency of natural resonances of hydrogen, is stimulated.

6. A device for recovering hydrogen from a gas stream, wherein a

characterized at least for the most part with a part of the gas stream filled area of an at least largely filled with hydrogen area by a semipermeable partition, characterized in that the semipermeable partition wall of ferritic iron and / or pig iron and / or pure iron.

7. Apparatus according to claim 6, characterized by an interior (69) surrounding the housing (67) with at least one, arranged in the housing (67), with a part of the gas stream at least partially filled area of a region filled with mostly hydrogen (74 ) separating semipermeable partition of preferably ferritic iron and / or pig iron and / or pure iron.

8. The device according to claim 6 or 7, characterized in that the at least one semi-permeable partition wall is formed as at least one tube (75) through which and / or the gas flow can be passed and in particular within the housing (67) a plurality, preferably the same , Tubes (75) are arranged.

9. A process for the recovery of hydrogen from a gas mixture, which

contains at least hydrogen and at least one other gas, thereby characterized in that the hydrogen is separated by means of a semi-permeable partition at least largely consisting of ferritic iron and / or pig iron and / or pure iron from the gas mixture.

A method according to claim 9, characterized in that the semipermeable partition by means of electrical current and / or light and / or a magnetic field, preferably in a frequency in the region of the natural resonance of the hydrogen is excited.