KR102012010B1 - Separation membrane, hydrogen separation membrane including separation membrane and device including hydrogen separation membrane - Google Patents

Abstract

A separator comprising at least one Group 5 element and Ge is provided, and a hydrogen separator and a hydrogen separator including the same are provided. The alloy has a crystal structure of a body centered cubic structure in which the Group 5 element and the Ge element are formed together.

Description

Separation membrane, a hydrogen separation membrane including the same and a hydrogen separation apparatus including the hydrogen separation membrane {SEPARATION MEMBRANE, HYDROGEN SEPARATION MEMBRANE INCLUDING SEPARATION MEMBRANE AND DEVICE INCLUDING HYDROGEN SEPARATION MEMBRANE}

A separator, a hydrogen separator including the same, and a hydrogen separator including the hydrogen separator.

BACKGROUND OF THE INVENTION Pd-based metals have been widely known as a membrane for selectively separating only hydrogen gas from a gas mixture containing hydrogen gas. The Pd-based metal forms a face-centered cubic structure (FCC), which allows selective separation of hydrogen through hydrogen dissolution and diffusion through space in a unit cell. However, the high unit cost of Pd-based metals acts as a limiting factor for commercialization.

Accordingly, there is a rapid increase in the need for a hydrogen-competitive membrane that is at least as good as a Pd-based metal and has a hydrogen permeation performance superior to that of the Pd-based metal hydrogen separator, while being competitive in cost.

One embodiment of the present invention is to provide a separation membrane having excellent hydrogen permeation characteristics while suppressing hydrogen embrittlement destruction and excellent oxidation stability.

Another embodiment of the present invention is to provide a hydrogen separation membrane comprising the separation membrane.

Another embodiment of the present invention to provide a hydrogen separation device including the hydrogen separation membrane.

According to one embodiment of the invention, an alloy comprising at least one Group 5 element and at least one Group 14 element, wherein the at least one Group 5 element and the at least one Group 14 element in the alloy A separator comprising a crystal structure of a body centered cubic structure is provided.

The lattice constant of the crystal structure of the alloy may be present in the range of about 98% to about 105% of the lattice constant of the crystal structure formed of only the at least one Group 5 element at room temperature.

The separator may be formed as a nonporous dense membrane structure having a porosity of less than about 1% by volume or a porosity of about 0% by volume.

The at least one group 14 element may be Ge or Si.

The alloy may include about 0.1 to 20 atomic% of the at least one Group 14 element.

The alloy may comprise an additional metal that is one selected from the group comprising Zr, Ti, Y, Ni, Al, and combinations thereof.

The additional metal may form a body centered cubic structure with the at least one Group 5 element and the at least one Group 14 element in the alloy.

The alloy may comprise about 0.1 to about 20 atomic percent Ge or Si, and about 0.1 to about 30 atomic percent of the additional metal.

The separator may have a thickness of about 1 μm to about 500 μm.

According to another embodiment of the present invention, a hydrogen separation membrane including the separation membrane is provided.

The hydrogen separator has a hydrogen solubility measured at about 0.1 to about 1 MPa hydrogen pressure and about 400 ° C. (H / M, where H is the number of moles of hydrogen atoms and M is the number of moles of metal atoms of the alloy). May be from about 0.2 to about 0.6.

Hydrogen permeability of the hydrogen separation membrane (hydrogen permeability) is at about 400 ℃ conditions of about 1.0 × 10 ^-8 to about ^{10.0 × 10 -8 mol / m *} s * Pa 1/2 Can be.

The hydrogen separation membrane may further include a catalyst layer on one or both surfaces of the separation membrane.

In the hydrogen separation membrane, the separation membrane and the catalyst layer may be formed in contact with each other.

The catalyst layer includes at least one selected from the group consisting of Pd, Pt, Ru, Ir, and combinations thereof, and at least one alloy selected from the group consisting of Cu, Ag, Au, Rh, Ni, Fe, and combinations thereof. can do.

According to yet another embodiment of the present invention, there is provided a chamber comprising a chamber for supplying a mixed gas including hydrogen gas; A discharge chamber including discharge means for separating hydrogen gas; And a hydrogen separation device including the hydrogen separation membrane, wherein one surface of the hydrogen separation membrane is in contact with the chamber and the other surface is in contact with the discharge chamber.

In one embodiment, the hydrogen separation membrane is formed in a tubular shape, a cylindrical chamber partition wall larger than the diameter of the tubular hydrogen separation membrane is formed on the outside of the hydrogen separation membrane, the space between the chamber partition and the hydrogen separation membrane as a chamber The tubular hydrogen separator may be formed as a discharge chamber through which hydrogen is discharged.

In another embodiment of the present invention, a method of manufacturing a separator comprising heating an at least one Group 5 element and at least one Group 14 element to form an alloy, and rolling the alloy to form a separator. Is provided.

The at least one group 14 element may be Ge or Si.

In another embodiment of the present invention, there is provided a hydrogen separation device according to the embodiment, providing a hydrogen-containing gas to the chamber of the hydrogen separation device, by purifying hydrogen through the hydrogen separation membrane of the hydrogen separation device purification A hydrogen purification method is provided that includes.

The separation membrane has excellent hydrogen permeability, but has a high resistance to hydrogen embrittlement fracture, thereby effectively improving durability, and the hydrogen separation membrane including the same not only separates hydrogen of high purity, but also effectively improves durability.

1 (a) and (b) show a schematic view of the crystal lattice that can be formed in the separator according to an embodiment of the present invention.
2 is a schematic view showing a mechanism in which hydrogen gas is separated through a hydrogen separation membrane according to another embodiment of the present invention.
3 is a schematic view of a hydrogen separation device according to another embodiment of the present invention.
4 is a schematic view of a hydrogen separation device including a tubular separator according to another embodiment of the present invention.
FIG. 5 is a graph showing the results of pressure-concentration-temperature (PCT) evaluation for the hydrogen separation membranes prepared in Examples 1 and 2 and Comparative Example 1. FIG.
6 is XRD graphs measured before and after hydrogen solubility for the hydrogen separation membranes prepared in Example 1 and Comparative Example 1, respectively.
FIG. 7A is an XRD measurement graph of the hydrogen separation membranes prepared in Examples 1, 2, and Comparative Example 1, and (b) is an enlarged view of a portion showing the highest peak in (a). .
8 is a graph showing the results of pressure-concentration-temperature (PCT) evaluation for the hydrogen separation membranes prepared in Examples 3 and 4. FIG.
9 is XRD graphs measured before and after hydrogen solubility for the hydrogen separation membranes prepared in Examples 3 and 4 and Comparative Example 4, respectively.
FIG. 10 is an enlarged view of a portion showing the highest peak in FIG. 9.

Hereinafter, an embodiment will be described in detail so that a person skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

The present invention may be embodied in many different forms and is described with reference to the drawings as necessary and is not limited to the embodiments described herein. Since the size and thickness of each component shown in the drawings of the present specification are arbitrarily shown for convenience of description, the present invention is not necessarily limited to the illustrated. In addition, the size and thickness of each component shown in the drawings are arbitrarily exaggerated for convenience of description, the present invention is not necessarily limited to the illustrated.

According to one embodiment of the present invention, an alloy including at least one Group 5 element and at least one Group 14 element, wherein the at least one Group 5 element and the at least one Group 14 element in the alloy A separator comprising a crystal structure of a body centered cubic structure is provided.

The separator may be used as a separator capable of selectively separating a specific gas. When the alloy is applied to the separator, there is an advantage that can be operated at a high temperature in contrast to the case of the separator made of a polymer.

At least about 80% by volume of the alloy may form a crystal structure of body centered cubic structure.

According to another embodiment of the present invention, a hydrogen separation membrane module including the separation membrane is provided. The hydrogen separator is a separator that selectively separates only hydrogen gas from a gas mixture containing hydrogen gas, and includes a crystal structure of a body centered cubic structure that easily dissolves and diffuses hydrogen, thereby providing high hydrogen permeability. Has As a result, the hydrogen separation membrane is capable of high purity hydrogen separation. For example, the hydrogen separation membrane may have a crystal structure of about 80% by volume or more of the alloy having a body centered cubic structure. The separator having a high level of crystal structure as described above may be suitable for use as a hydrogen separator.

The hydrogen separation membrane is steam reforming, coal gasification, water gas shift reaction (WGS). It can be applied to the technical field for selectively permeating and separating only H ₂ gas from the gas containing H ₂ , CO ₂ , CO, etc. generated through the reaction. For example, the present invention can be applied to fields such as high purity hydrogen generator, fuel cell hydrogen regenerator, gas separation hydrogen separation membrane, and H ₂ / CO ₂ separation membrane.

The separated hydrogen may be used for electricity generation by hydrogen combustion, which is a clean energy source, or may be used as a chemical raw material (NH ₄ , olefin, etc.) or for petroleum refining. On the other hand, since the gas remaining after the removal of hydrogen is a gas composed of a high concentration of CO ₂ components, such a CO ₂ rich gas (CO ₂ rich gas) may be selectively collected and stored to use for the purpose of removing CO ₂ .

The hydrogen separation membrane first adsorbs hydrogen gas (H ₂ ) among various gases including hydrogen, and the adsorbed hydrogen gas (H ₂ ) is dissociated with hydrogen atoms (H) at the surface of the hydrogen separation membrane. The dissociated hydrogen atom (H) is permeated through the separator. The hydrogen atom (H) is dissolved (or dissolved) and diffused through the tetrahedral or octahedral interstitial space of the unit cell of the separator. Permeation occurs (MD Dolan, J. membrane science 362, 12-28 (2010)). The hydrogen atom (H) that has passed through the membrane is recombined again to form hydrogen gas (H ₂ ), and is then separated by desorption of the hydrogen separation membrane.

(A) and (b) of FIG. 1 are schematic diagrams showing types of crystal lattice that the separator may include, and show crystal lattice that an alloy including at least one Group 5 element and Ge may be formed. Group 5 elements form a body-centered cubic structure, in which FIG. 1 (a) shows a case where Ge is substituted in the body of the body-centered cubic structure formed by the group 5 element, and FIG. 1 (b) shows the group 5 The case where Ge is substituted at the vertex of the body-centered cubic structure formed by the element is shown. That is, the separator has a crystal structure of a body centered cubic structure formed by the Group 5 element and the Ge.

The separator may be formed as a nonporous dense membrane structure having a porosity of less than about 1% by volume and a porosity of about 0% by volume. In this way, it is formed as a dense membrane structure, and only the substance to be separated can be selectively transmitted and separated. When the separation membrane is applied as a hydrogen separation membrane is formed as a dense membrane structure to selectively separate only hydrogen permeate.

Membranes composed of at least one pure Group 5 element may form embrittlement by forming a metal hydride during hydrogen permeation, which is called 'hydrogen embrittlement'. When external stress is applied to the fractured parts, hydrogen embrittlement fracture occurs. In order to suppress hydrogen embrittlement destruction, hydrogen solubility must be lowered. The separation membrane lowers the hydrogen solubility as compared with a membrane composed of at least one pure Group 5 element by alloying at least one Group 14 element with at least one Group 5 element. Since the Group 14 element is a covalently bonded element and strongly binds to the Group 5 element to lower the hydrogen affinity of the alloy, it is possible to lower the hydrogen solubility and to suppress the formation of a metal hydrogen compound that is a brittle phase. For example, Nb, a Group 5 element, has a large lattice size, so most of the additional elements reduce the lattice size of Nb. On the other hand, Ge element, which is one of group 14 elements, makes the lattice size of Nb rather large. In terms of lattice size only, as the lattice size increases, the hydrogen solubility may rather increase due to the increase in the space where hydrogen can be dissolved. When the solution energy (eV) of hydrogen in the metal according to the lattice size is calculated through the DFT (Density Functional Theory) calculation, the solution energy of hydrogen increases as the lattice size increases. In addition to placing a hydrogen Ge right side in the alloy (1 ^st nearest neighbor), it can be seen that the absolute value of the decrease in the employment of hydrogen energy value. It can be seen that the Group 14 element, when alloying with the Group 5 element, significantly lowers the affinity with hydrogen and consequently suppresses the generation of the metal hydrogen compound. Therefore, the hydrogen affinity is reduced by the addition of the Group 14 element, thereby improving the odor resistance through the suppression of the generation of metal hydrogen compounds (Hydride), while not significantly lowering the hydrogen solubility, thereby obtaining high hydrogen permeability. There is an advantage that it can.

The Group 5 element may be, for example, Nb, V or Ta.

The Group 14 element may be Ge or Si.

Alloying the Group 14 element to form a crystal structure as shown in Figs. 1A and 1B changes the solid solution energy in the metal of hydrogen, thereby reducing the hydrogen solubility. Hydrogen solubility means the concentration of hydrogen dissolved in the metal and is calculated by the molar ratio (H / M) of the hydrogen (H) and metal (M) atoms dissolved.

On the other hand, when the Group 14 element is alloyed with the at least one Group 5 element, the lattice constant becomes larger than the crystal lattice formed by the pure at least one Group 5 element. For example, since the lattice constant of the Ge element, which is a Group 14 element, is about 5.6Å, which is larger than that of the Group 5 element, when alloyed with a Group 5 element, the lattice constant of the alloy is larger than that of the pure Group 5 element, or other elements (Ni, Fe). , Shrinkage is small compared with the lattice size of the alloy by the addition of Mn). For example, Nb, one of the Group 5 elements, has a lattice constant of about 3.3 mA. For example, the separator may have a lattice constant of about 3.2 to about 3.4 GPa at room temperature (about 25 ° C.). Specifically, the separator may have a lattice constant of about 3.22 to about 3.38 GPa, and more specifically, the separator may have a lattice constant of about 3.25 to about 3.35 GPa. As another example, the lattice constant of the crystal structure of the alloy of V and Ge may be about 2.9 to about 3.2 kPa at room temperature (about 25 ° C.).

Since the lattice constant of the crystal structure is very small or rather large, the alloy has high hydrogen permeability while suppressing brittle fracture of hydrogen. In one embodiment, the separator may be present in the range of about 97% to about 105% when the lattice constant of the crystal structure is 100% at room temperature, the lattice constant formed of only the at least one Group 5 element.

Lowering the hydrogen solubility may be desirable in terms of inhibiting hydrogen embrittlement, but may be undesirable in terms of performance since the hydrogen permeability is also lowered. As described above, the separator may lower the hydrogen solubility by alloying at least one Group 14 element with at least one Group 5 element, but may have a lattice constant larger than that of the crystal lattice formed by the pure at least one Group 5 element. Therefore, hydrogen permeability can be secured without excessively lowering the hydrogen solubility. At the same time, since the Group 14 element has a low hydrogen affinity, the hydrogen embrittlement problem can also be effectively suppressed. As a result, the separation membrane is excellent in hydrogen permeability while solving the hydrogen embrittlement problem, it can be usefully applied as a hydrogen separation membrane.

The separator may be designed in accordance with the characteristics of the membrane to be applied by changing the content of the Group 14 element. Specifically, the separator may include a Group 14 element in an amount of about 0.1 to about 20 atomic%, specifically about 1 to about 15 atomic%, and more specifically, about 5 to about 10 atomic%. Separation membrane containing a Group 14 element in the content range can improve the permeability while excellent hydrogen permeability characteristics. As can be seen from the above content range, the separator can be alloyed with a small amount of Group 14 elements to secure useful properties as a hydrogen separator.

The separator may be an alloy further comprising another additional metal in addition to at least one Group 5 element and at least one Group 14 element, and may be, for example, a three-component alloy, a four-component or five-component alloy, or the like. The additional metal may be one selected from the group comprising Zr, Ti, Y, Ni, Al, and combinations thereof. The additional metal may be further included to increase ductility of the separator. Increasing the ductility of the separator may help to alleviate hydrogen embrittlement problems.

The additional metal may also form a body-centered cubic structure together with the Group 5 and Group 14 elements in the alloy. The alloy further comprising the additional metal may form some intermetallic compound, but is mostly about 80 vol. Of the alloy even in a separator made of an alloy further comprising the additional metal by forming a crystal structure of a body centered cubic structure. More than% may be composed of the crystal structure of the body-centered cubic structure.

When the separator further includes the additional metal, the alloy included in the separator may include about 0.1 to about 20 atomic% of the Group 14 element and about 0.1 to about 30 atomic% of the additional metal.

As described above, the hydrogen separator prepared using the separator has a reduced hydrogen solubility, and specifically, the hydrogen solubility measured at about 0.1 to about 1 MPa hydrogen pressure and about 400 ° C. in the Nb alloy ( H / M, where H is the number of moles of hydrogen atoms, M means the number of moles of metal atoms in the alloy) can be from about 0.01 to about 0.70, more specifically from about 0.05 to about 0.65. More specifically, hydrogen solubility measured at about 0.7 MPa [= about 7 bar] hydrogen pressure and about 400 ° C. (H / M, where H is the number of moles of hydrogen atoms, and M is the number of moles of metal atoms in the alloy. Mean), from about 0.2 to about 0.6.

In addition, the hydrogen separation membrane prepared using the separator prepared as described above has excellent hydrogen permeability. Hydrogen permeability can be calculated by the following equation.

[Equation 1]

Permeability = solubility factor (S) × diffusion coefficient (D)

Hydrogen permeability (hydrogen permeability) of the separator is from about 400 ℃ conditions of about 1.0 × 10 ^-8 to about ^{10.0 × 10 -8 mol / m *} s * Pa 1/2 One can, in particular from about 2.0 × 10 ^-8 to about ^{5.0 × 10 -8 mol / m *} s * Pa 1/2 may be, more specifically, about 3.0 × 10 ^-8 to about 5.0 × 10 ^{-8 mol / m * s * Pa 1} /2 may be. The separator may have a thickness of about 1 to about 500 μm, specifically about 10 to about 100 μm. When the separator has a thickness in the above range, it may have a permeability suitable for application to the separator. The thickness may be the thickness of the hydrogen separation membrane 23 of FIG. 3 or the thickness of the hydrogen separation membrane 33 tube of FIG. 4.

The separator may be prepared according to a known alloy production method, it is not limited to that method. For example, hot rolling / cold rolling / plating in order to uniformly dissolve each metal by arc melting, induction melting, etc., and to produce a film having a desired thickness. Separation membrane can be manufactured by a process.

The hydrogen separation membrane may be a catalyst layer is further formed on one side or both sides of the separation membrane. FIG. 2 illustrates a hydrogen separation membrane 10 in which a catalyst layer 12 is formed on both surfaces of the separation membrane 11, and schematically illustrates a mechanism through which hydrogen gas H ₂ passes through the hydrogen separation membrane. As described above, since the permeation of hydrogen through the hydrogen separation membrane 10 is made by the hydrogen atom, dissociation of the hydrogen molecule (H ₂ ) to the hydrogen atom (H) is necessary. The catalyst layer 12 may act as a catalyst to help dissociation of such hydrogen molecules. Hydrogen selectively permeated through the hydrogen separation membrane 10 needs to be recombined again with hydrogen molecules, and such recombination may be accelerated by the catalyst layer 12.

The catalyst layer 12 may be made of a material capable of catalyzing a reaction of dissociating hydrogen molecules or recombining hydrogen molecules on the surface of the hydrogen separation membrane 10 as described above. Specifically, Pd, Pt At least one selected from the group consisting of Ru, Ir, and combinations thereof, and at least one alloy selected from the group consisting of Cu, Ag, Au, Rh, Ni, Fe, and combinations thereof.

The thickness of the catalyst layer 12 may be, for example, about 50 to about 1,000 nm, specifically about 100 to about 300 nm. When the catalyst layer 12 has a thickness in the above range, the catalyst layer 12 may function smoothly without inhibiting the permeability of the entire hydrogen separation membrane 10.

The hydrogen separation membrane may be formed by contacting the separation membrane 11 and the catalyst layer 12. That is, since the hydrogen separation membrane has excellent hydrogen separation characteristics, the hydrogen separation membrane may include only the separation membrane 11 and the catalyst layer 12 without further including an additional auxiliary layer to achieve a desired effect.

In another embodiment of the present invention, a hydrogen separation device including the hydrogen separation membrane is provided.

In one embodiment, the hydrogen separation device comprises: a chamber having means for supplying a mixed gas comprising hydrogen gas; A discharge chamber including discharge means for separating hydrogen gas; And the hydrogen separation membrane.

The hydrogen separation membrane is positioned such that one surface of the hydrogen separation membrane is in contact with the chamber and the other surface is in contact with the discharge chamber.

11 is a schematic diagram schematically showing the hydrogen separation device 20 according to one embodiment. When the mixed gas containing the hydrogen gas is introduced into the chamber 22 through the supply means 21 of the mixed gas containing the hydrogen gas, only the hydrogen gas in the mixed gas is selectively discharged through the hydrogen separation membrane 23. Separated by). The separated hydrogen gas may be recovered through the discharge means 25. The hydrogen separation device 20 may further include a means 26 for recovering the remaining gas from which the hydrogen gas is separated. Since the hydrogen separation device 20 is illustrated in a simplified form for convenience of description, it may further include additional components according to the use.

12 is a schematic view showing another embodiment in which the hydrogen separation device 30 is formed in a tubular shape. The hydrogen separation device 30 includes a tubular hydrogen separation membrane 33, and a cylindrical chamber partition wall 36 larger than the diameter of the tubular hydrogen separation membrane is formed outside of the hydrogen separation membrane 33 to form the chamber. A space between the partition 36 and the hydrogen separation membrane is formed as the chamber 32, and the inside of the tubular hydrogen separation membrane is formed as the discharge chamber 34 through which hydrogen is discharged. The chamber 32 may further include a supply means (not shown) of a mixed gas including hydrogen gas and a recovery means (not shown) of remaining gas from which hydrogen gas is separated. In addition, a discharge means (not shown) for discharging the separated hydrogen gas in the discharge chamber 34 may be further provided.

In another embodiment, in the case of including the tubular hydrogen separation membrane 33, a mixed gas is supplied into the tubular hydrogen separation membrane 33 as opposed to the case of FIG. 4, and hydrogen in the mixed gas is tubular hydrogen. Passing through the separator 33 may be separated to the outside of the tubular hydrogen separation membrane 33 may be formed to discharge hydrogen. That is, the inside of the hydrogen separation membrane 33 is formed as a chamber through which the mixed gas is supplied, and the outside of the hydrogen separation membrane 33 is formed as the discharge chamber through which hydrogen is discharged.

In another embodiment of the present invention, a method of manufacturing a separator comprising heating an at least one Group 5 element and at least one Group 14 element to form an alloy and rolling the alloy to form a separator. Is provided.

The at least one group 14 element may be Ge or Si.

In another embodiment of the present invention, there is provided a hydrogen separation device according to the embodiment, providing a hydrogen-containing gas to the chamber of the hydrogen separation device, by purifying hydrogen through the hydrogen separation membrane of the hydrogen separation device purification A hydrogen purification method is provided that includes.

The following presents specific embodiments of the present invention. However, the embodiments described below are merely for illustrating or explaining the present invention in detail, and thus the present invention is not limited thereto.

( Example )

Example  One

Nb and Ge metals are uniformly dissolved in an arc melting furnace to form an alloy to prepare a hydrogen separator consisting of a separator having a thickness of 50 μm. Specifically, a material was prepared by weighing 95 atomic% Nb and 5 atomic% Ge, and then placed in the arc melting furnace to prevent oxidation by injecting Ar gas in a high vacuum (5x10 ^-5 torr or lower). After making the condition, the current is increased to melt the material and then cooled sufficiently. In order to manufacture a film having a desired thickness, annealing is performed after the cold rolling process, and then a thin Pd film is treated by an rf sputtering process on both sides of the film to coat a 200 nm thickness to prepare a hydrogen separation membrane. do.

Example  2

A hydrogen separation membrane was prepared in the same manner as in Example 1, except that the membrane was prepared using a material prepared by weighing 90 atom% Nb and 10 atom% Ge.

Example  3

The V and Ge metals are uniformly dissolved in an arc melting furnace to form an alloy to prepare a hydrogen separator consisting of a separator having a thickness of 50 μm. Specifically, a material was prepared by weighing 95 atomic% Nb and 5 atomic% Ge, and then placed in the arc melting furnace to prevent oxidation by injecting Ar gas in a high vacuum (5x10 ^-5 torr or lower). After making the condition, the current is increased to melt the material and then cooled sufficiently. In order to manufacture a film having a desired thickness, annealing is performed after the cold rolling process, and then a thin Pd film is treated by an rf sputtering process on both sides of the film to coat a 200 nm thickness to prepare a hydrogen separation membrane. do.

Example  4

A hydrogen separation membrane was prepared in the same manner as in Example 3, except that the membrane was prepared using a material prepared by weighing V 95 atomic% and Si 5 atomic%.

Comparative example  One

A 50 μm thick hydrogen separation membrane made of pure Nb was prepared.

Comparative example  2

A hydrogen separation membrane was prepared in the same manner as in Example 1, except that the membrane was prepared using a material prepared by weighing 95 atomic% Nb and 5 atomic% Fe.

Comparative example  3

A hydrogen separation membrane was prepared in the same manner as in Example 1, except that the membrane was prepared using a material prepared by weighing 100 atomic% Pd.

Comparative example  4

Only the V metal was uniformly dissolved in an arc melting furnace to produce a hydrogen separator consisting of a separator having a thickness of 50 μm. Specifically, a material is prepared by weighing 100 atomic% of V elements, and then the material is placed in the arc melting furnace, and the arc melting furnace is injected with Ar gas under a high vacuum (5x10 ^-5 torr or less) to form an oxidation preventing condition. The current is melted by increasing the current and then cooled sufficiently. In order to manufacture a film having a desired thickness, annealing is performed after the cold rolling process, and then a thin Pd film is treated by an rf sputtering process on both sides of the film to coat a 200 nm thickness to prepare a hydrogen separation membrane. do.

Experimental Example  1: hydrogen Employment  evaluation

For the hydrogen separation membranes prepared in Examples 1, 2, Comparative Example 2 and Comparative Example 3, in order to measure the hydrogen solubility by hydrogen pressure at 400 ° C. according to JIS H7201 standard, and to evaluate the hydrogen solubility, PCT Conduct a pressure-concentration-temperature evaluation. Table 1 lists the hydrogen solubility values at 0.7 MPa.

5 is a PCT graph for Example 1, Example 2, and Comparative Example 1. FIG.

Example 1 Example 2 Comparative Example 2 Comparative Example 3 Hydrogen Solubility (H / M) 0.50 0.45 0.65 ~ 0.02

Example 1 and Example 2 it can be confirmed that the hydrogen solubility is lower than the comparative example 2.

For the hydrogen separation membranes prepared in Examples 3 and 4, the pressure-concentration-temperature (PCT) was measured to measure the hydrogen solubility of each hydrogen pressure at 400 ° C. according to JIS H7201. Proceed with the evaluation.

8 is a PCT graph for Example 3 and Example 4. FIG.

As can be seen from FIG. 8, both Si and Ge are considered to have an effect of reducing hydrogen solubility compared to pure V (H / M = 0.55), and hydrogen concentration (H / M) under hydrogen pressure of 0.7 MPa (7 bar). ) Was 0.21 for V-Si (5 atomic%) and 0.33 for V-Ge (5 atomic%).

Experimental Example  2: Body Cubic Structure  Evaluation of oils and fats and the generation of metal hydrogen compounds

The hydrogen separation membranes prepared in Example 1 and Comparative Examples 1 and 2 were cooled to room temperature (about 25 ° C.) after solid solution of hydrogen to 3 MPa, and then subjected to X-ray diffraction analysis (XRD) to obtain peaks corresponding to metal hydrogen compounds. It is listed in Table 1 to evaluate the production. 6 is a result of measuring the XRD for the hydrogen separation membranes prepared in Example 1 and Comparative Example 1. In Example 1, it can be confirmed that the body-centered cubic structure is well maintained, and it is confirmed that the metal hydrogen compound hardly occurs even after hydrogen solid solution.

On the other hand, the peak showing that the metal hydrogen compound was formed after the hydrogen solubility in the hydrogen separation membrane of Comparative Example 1 can be seen (indicated by the dotted circle in the XRD peak), from the XRD results before the hydrogen solubility of the hydrogen separation membrane of Comparative Example 1 It is confirmed that the metal hydrogen compound is not present before hydrogen solubility.

In addition, the hydrogen separation membranes prepared in Examples 3, 4, and Comparative Example 4 were cooled to room temperature (about 25 ° C.) after solid solution of hydrogen to 3 MPa, and then subjected to X-ray diffraction analysis (XRD) to perform metal hydrogen compounds It is shown in FIG. 9 by evaluating whether the peak corresponding to the present invention is produced. From Fig. 9, it can be confirmed that the body-centered cubic structure is well formed in both Example 3, Example 4, and Comparative Example 4.

Experimental Example  3: grid size evaluation

X-ray diffraction analysis (XRD) is performed on the hydrogen separation membranes prepared in Example 1, Example 2 and Comparative Example 1. 7 (a) shows XRD results for Example 1, Example 2, and Comparative Example 1. FIG. FIG. 7B is an enlarged view of the maximum peak portion at the measurement angle (2θ) 35 to 40 positions. The crystal lattice size can be obtained from the angle of XRD, and compared with Comparative Example 1 (~ 3.295 mm 3), Examples 1 and 2 have values of 3.295 to 3.303 mm 3, indicating that the lattice size is not reduced or enlarged. have.

FIG. 9 shows XRD graphs of the hydrogen separation membranes prepared in Examples 3 and 4, and Comparative Example 4, and FIG. 10 shows a maximum peak portion at the 40 to 45 measurement angle (2θ) of FIG. 9. It is enlarged. The crystal lattice size can be obtained from the angle of XRD, and compared with Comparative Example 4 (˜3.021 mm 3), Examples 3 and 4 have values of 3.018 to 3.032 mm 3, indicating that the lattice size is not reduced or enlarged. Can be.

Experimental Example  4: hydrogen permeation characteristics evaluation

Based on the above results, the hydrogen permeability coefficients (Permeability, D _H x S _H ) of the hydrogen separation membranes prepared in Examples 1 to 4 and Comparative Examples 1 to 3 were measured. Where ((P _{H2 , in} ) ^1/2- (P _{H2 , out} ) ^1/2 ) is the difference between the square roots of the hydrogen partial pressures of the hydrogen input and output of the hydrogen separator.

[Equation 2]

In the above formula, Flux (J) is the hydrogen permeation rate per unit area, L is the thickness of the hydrogen separation membrane, D _H is the diffusion coefficient of the hydrogen atoms, and S _H is the hydrogen solubility.

Table 2 lists the hydrogen permeability results calculated according to Equation 2 above. In Table 2, it can be confirmed that Examples 1 to 4 have better hydrogen permeation characteristics than Comparative Example 3.

Example
One Example 2 Example 3 Example 4 Comparative Example 1
(Nb) Comparative Example 2
(Nb-Fe) Comparative Example 3
(Pd) Hydrogen permeability
^{(x10 -8 mol / m * s} * Pa 1/2) 5 4 6 5 Measuring
Destruction Measuring
Destruction 1.6

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of the invention.

1: group 5 element 2: group 14 element
10: hydrogen separation membrane 11: separation membrane
12: catalyst layer 20, 30: hydrogen separation device
21: supply means of a mixed gas containing hydrogen gas
22, 32: chamber 23, 33: hydrogen separation membrane
24, 34: discharge chamber 26: recovery means
25: means for discharging separated hydrogen gas
36: chamber bulkhead

Claims (20)

An alloy consisting of at least one Group 5 element from 90 atomic% to 95 atomic% and at least one Group 14 element from 5 atomic% to 10 atomic%, wherein the at least one Group 14 element is Ge or Si; The at least one Group 5 element and the at least one Group 14 element in an alloy comprises a crystal structure of a body centered cubic structure. The method of claim 1,
The lattice constant of the crystal structure of the alloy is in the range of 98% to 105% of the lattice constant of the crystal structure formed of only the at least one Group 5 element at room temperature. The method of claim 1,
Separation membrane having a porosity of less than 1% by volume of the separator. delete delete delete delete delete The method of claim 1,
Separation membrane having a thickness of 1 to 500㎛. A hydrogen separation membrane comprising the separation membrane of any one of claims 1 to 3. The method of claim 10,
Hydrogen solubility measured at 0.1 to 1 MPa hydrogen pressure and 400 ° C. (H / M, where H is the number of moles of hydrogen atoms and M is the number of moles of metal atoms of the alloy) of 0.1 to 1 hydrogen separation membrane . The method of claim 10,
Hydrogen permeability at 400 ℃ conditions (hydrogen permeability) is 1.0 × 10 ^-8 to about ^{10.0 × 10 -8 mol / m *} s * Pa 1/2 of a hydrogen separation membrane. The method of claim 10,
Hydrogen separation membrane further comprising a catalyst layer formed on one side or both sides of the separation membrane. The method of claim 13,
A hydrogen separation membrane formed by contacting the separation membrane and the catalyst layer. The method of claim 14,
The catalyst layer comprises at least one selected from Pd, Pt, Ru, Ir, and combinations thereof and at least one alloy selected from Cu, Ag, Au, Rh, Ni, Fe, and combinations thereof. A hydrogen separation membrane according to claim 10;
A chamber having means for supplying a mixed gas containing hydrogen gas; And
A discharge chamber including discharge means for separating hydrogen gas,
The hydrogen separator is positioned so that one surface of the hydrogen separator in contact with the chamber, the other surface in contact with the discharge chamber. The method of claim 16,
The hydrogen separation membrane is formed in a tubular shape,
A cylindrical chamber partition wall larger than the diameter of the tubular hydrogen separation membrane is formed outside the hydrogen separation membrane,
And a space between the chamber partition wall and the hydrogen separation membrane is formed as a chamber, and the tubular hydrogen separation membrane is formed as a discharge chamber through which hydrogen is discharged. 5 to 10 atomic% of at least one Group 5 element of 90 to 95 atomic% and a Group 14 element of Ge or Si are heated to form an alloy, and the alloy is rolled to form a separator. Method for producing a separation membrane comprising. delete Providing a hydrogen separation device according to claim 16,
Providing a hydrogen containing gas to the chamber of the hydrogen separation device,
Purifying hydrogen by diffusing hydrogen through the hydrogen separation membrane of the hydrogen separation device.

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