JPS5896841A - Multicomponent titanium alloy for occluding hydrogen - Google Patents

Abstract

PURPOSE:To obtain a hydrogen occluding alloy which occludes a large amount of hydrogen and releases it easily by blending Ti, Fe and Ni as basic components with adequate amounts of specified metallic elements. CONSTITUTION:This multicomponent Ti alloy for occluding hydrogen is represented by a formula TiFe1-xNiyAzBa [where A is Nb, V or Zr, B is Al, Nb, Cr, Co, Mn, Mo, V, Zr or a rare earth element, x=0.01-0.3, y=0.01-0.3, z= 0.01-0.2, a <=0.2 (anot equal to 0), 1.0 <=(1-x+Y+z+a) <=1.2, and A and B are different elements at all times]. Ti, Fe, Ni and the elements A, B are weighed, mixed and press-molded into an arbitrary shape, and the molded body is put in an arc melting furnace and melted by heating in an inert atmosphere. Thus, the desired alloy can be manufactured easily.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a titanium multi-component hydrogen storage alloy.
Activation by hydrogen is extremely bulky, and a large amount of hydrogen can be produced in the form of hydride @ml, and the difference between the hydrogen storage pressure and release pressure, that is, the hydrogen gas, is extremely small, and it can be activated and quickly activated with a small amount of heating. This invention relates to a titanium multi-component hydrogen storage alloy that releases hydrogen.

Hydrogen is regarded as a new energy source to replace fossil fuels because it is clean, has no resource limitations, and can be transported and stored as a commodity.

However, since hydrogen is a gas at room temperature and its liquefaction temperature is very low, it is important to develop a storage technology for it.This storage method involves storing hydrogen in a metal and storing it as a metal hydride. has been attracting attention recently. In addition, the hydrogen absorption/release reaction by metals is reversible, and a considerable amount of reaction heat is generated or absorbed during the reaction, and the hydrogen absorption/release pressure depends on temperature. Research is also progressing on the application of this technology to cooling/heating return equipment, internal heat engineering vehicles, pressure (mechanical) energy conversion equipment, etc.

The properties required of such a hydrogen storage material are: ■ being inexpensive and abundant in terms of resources, ■ being able to be activated and having a large amount of hydrogen storage, and ■ being able to absorb and release hydrogen at around room temperature. It has an equilibrium pressure, has low hysteria during storage and release, and 2) hydrogen storage and release reactions are reversible and have a high speed.

For example, as this type of hydrogen storage material, L-Nl is used.
, 10F@Ti, etc. are known, and these alloys have reversible hydrogen absorption and release reactions. Although 11iIIk is also large, it has drawbacks such as a moderate hydrogen storage and release reaction, a less than satisfactory activation, and a large hysteresis ratio69, which is considered a major practical problem.

The inventors of the present invention have focused on the above-mentioned circumstances and have conducted research to eliminate the above-mentioned drawbacks while retaining the features of conventional hydrogen storage alloys. As a result, it was discovered that by using a base alloy composition of TI, IF-, and Nl and adding appropriate amounts of specific metal elements to it, an alloy with excellent hydrogen storage properties that meets the above objectives can be obtained, and the present invention was based on this knowledge. completed.

That is, in the present invention, the general formula is T IF @ 1- x N
' This relates to a titanium multi-component hydrogen storage alloy represented by yAzBa, where A represents an element from Nb, V and zr, xtxo, 01NO, 8*ymo, 01 ~
0.81 geeo, 01~0.1! l l≦0.2
(However, 0 is excluded) and 1.0≦t-x+y10 dew+1≦
1. ! Moreover, the gist lies in the fact that it is adjusted to satisfy the fact that A and B are always different elements.

General 1 (TiFlF- or by forming a C, C4 type cubic crystal with the amount of N)
It has been confirmed that it forms intermetallic compounds such as d, which threatens hydrogen storage materials. However, all of these alloys require K11m and high pressure for activation, are easily affected by hydrogen purity, and have a large difference between hydrogen storage pressure and water m*output pressure, that is, hysteresis.1For example, T IF @ o,
s N lo, $! In the alloy, the hydrogen storage pressure is 1
While it is about 80 atm at 60°C, the hydrogen release pressure is about 4 atm, and the hysteresis is about 26 atm. Therefore, when storing and releasing hydrogen, it is necessary to heat or cool the hydrogen storage alloy or its metal hydride with a large temperature difference, or to pressurize or depressurize hydrogen with a large pressure difference. , the precious hydrogen storage capacity and hydrogenation reaction heat cannot be used effectively.

However, the above T i F @ 1 ++ a Nt d
or by replacing a part of the metals A and B with the metals A and B, or
By adding , activation by hydrogen becomes extremely easy,
Furthermore, it has been found that hysteria VXt can be significantly reduced, that is, the hydrogen storage alloy of the present invention is TI.

It is a ternary alloy consisting of TiF.
It can be represented by the general formula 1-xNl, A, B.

However, during the ceremony! is 0.01-0.8, y is 0.01-0.8
．． 1.0゜0.01~0.2, excluding a≦0.2CO), and these are 1.0≦(1-x+Y+s+a)≦1
．． It is assumed that relationship 2 is satisfied. ζ Here! or y is 0
．． If it exceeds 8, it will be difficult to release the occluded hydrogen, and smooth release will not be possible unless under high temperature heating or vacuum heating (or slightly reduced pressure heating) conditions. When i92 or Kaede exceeds 0.1, the hydrogen storage capacity of the alloy decreases, and the putative region of the hydrogen absorption/release pressure curve tends to become two-staged. It is preferable that iKutomi or Karasu is % smaller than y, and when X is 1, the preferable range of 腈 or a is below OJ (however, O is excluded).

From the preferred range of “+F*’l t a” above, T
When replacing part of the IF@1-4N alloy with metal and B, aTIF*1-xNl, A, B,! ff
(F1000 heat), the relationship y≧10a is established, and (1-violet+y+l+I)g+1. Maku T j F @
When adding metal and B to t-4N S a alloy, TIF・1-8Nl, A, B,
e The relationship of F≧Fuji + Maro is established, and Fuku + Eki≦0.2 (however, O is excluded), and 9X work y-4-g, x≧1
The relationship also holds true, and Hatake≦0.2 (excluding O), so these relationships are 1.0<(1-x+y+wealth+m)≦
1. ! becomes.

Although typical examples of cases in which all subordinates are added as replacements and additionally added are shown above, it is of course possible to add all subordinates in a range that spans both of these.

In this way, by adding appropriate amounts of metals A and B to the T I F @ 1 + d ” d alloy, activation of the alloy becomes extremely easy. For example, 'r1y@, 8Ni., 2
The alloy has a hydrogen pressure of 20 Kv'am and a hydrogenation reaction time of too many minutes at 28°C.
1" 0.1!ivO, 05NbO, 088 alloy is 80 minutes, and the hydrogenation reaction time is about 10 minutes for the pace alloy. It is shortened to less than 80 minutes, and activation is extremely easy. Moreover, r1ir
In the @o, gNjo, and g alloys, the hydrogen storage pressure is 150 atm and about 80 atm, whereas the hydrogen release pressure is about 4 atm, and the hysteresis is about 26 atm. Therefore, in order to store and release hydrogen, it is necessary to heat or cool the hydrogen storage alloy or its metal hydride with a large temperature difference, or to pressurize or depressurize hydrogen with a large pressure difference. However, the heat of hydrogenation reaction in the hydrogen storage capacity cannot be used effectively.
6VO,05Nb0.066 alloy has a hysteresis of approximately 1
When the pressure is 0 atm, the hysteresis V is reduced to 4 or less than that of the base alloy.

The method for producing the alloy of the present invention is not limited in any way and all known methods can be applied, but the most preferred method is the arc melting method. That is, each element of TI, F@, Nl, metallic aluminum, and B is weighed and mixed, then press-formed into an arbitrary shape, and then charged into an arc melting furnace and heated and melted in an inert atmosphere. It can be easily manufactured. The thus obtained nine-titanium multi-component hydrogen storage alloy is preferably used in powder form in order to expand the surface area and increase the hydrogen storage capacity.

In this way, the powdered hydrogen storage alloy obtained is extremely @J
bFC can be activated, and after activation, it rapidly stores and releases large amounts of hydrogen at relatively low temperature and pressure.
For example, fill an appropriate amount of the above-mentioned alloy powder, degas it under reduced pressure at a temperature of 200°C or less to activate it, and then apply hydrogen at a temperature of room temperature or higher to, for example, 80Kq/c.
By applying a hydrogen pressure of less than m, it is possible to store hydrogen up to approximately saturated II within a few minutes. Hydrogen can be efficiently released from the metal hydride in a short time by heating the hydride above room temperature, slightly reducing the pressure, or a combination of both.

The titanium multi-component hydrogen storage alloy of the present invention is roughly constructed as described above, and as will be made clear in the examples described later, it has all the performances required as a hydrogen storage material. The activation of WJ+ is extremely strong, and the hysteresis of hydrogen storage and release pressure has been significantly improved compared to conventional hydrogen storage alloys. Furthermore, this alloy can store a large amount of hydrogen at a high density, and the hydrogen storage and desorption reactions are completely reversible, so no matter how many times the hydrogen storage and desorption is repeated, no deterioration of the alloy itself is observed. It has various special features such as its luster being almost unaffected by impurity gases such as oxygen, II element, argon, and acid gas, making it an ideal hydrogen storage material. . Therefore, it exhibits excellent effects not only for its original use as a hydrogen storage material, but also for other uses that utilize the reaction heat associated with hydrogen storage and desorption reactions.

Next, examples of the present invention will be shown.

Example 1 Commercially available 'l''i, p@, Nl and metal A component and B
The atomic ratio of the components is TIF@:Ni:A:B=1:0.8
:0.15:0.0! ! 5:0.025, and charged it into a copper crucible of a high vacuum arc melting furnace.After creating a high-purity Ar atmosphere in the furnace, it was melted by heating at about 50°C and allowed to cool. TIF・0.8”0.16°,.2.
. ,. An alloy with a composition of 26 was prepared.

B Note that Mm refers to F・+Mg+A# and 8 in the rare earth element mixture.
It is a mixed metal containing a small amount of impurities such as 1st grade.

6. Grind each of the obtained alloys into T-120 pieces. (Collect 1 liter of hydrogen into a stainless steel hydrogen storage/release reactor, connect the reactor to an exhaust system, and degas it at a temperature under reduced pressure.) Then, 99.999% pure hydrogen is added to the reactor. was introduced and the hydrogen pressure was maintained below gQV3'', and hydrogen absorption occurred immediately at room temperature.After 9 hours, the hydrogen absorption was completed and the vessel was evacuated again to release hydrogen, thereby completing the activation process. Hydrogen with a purity of 99.999 was introduced into the reactor at a temperature above room temperature and a pressure below 20 K9/a1 to absorb hydrogen. Alternatively, it may be carried out by reducing the pressure or a combination thereof.

The relationship between the hydrogenation reaction time and the hydrogen storage concentration of each titanium multi-component hydrogen storage alloy was determined using the above method.
, 026N bO, 0215 is shown in FIG. 1, showing the hydrogenation reaction curve upon activation, and nine comparative examples are shown by dotted lines. B Ni. , 2 is a hydrogenation reaction curve upon activation in 9 cases using a ternary hydrogen storage alloy having a composition of 2.

As is clear from FIG. 1, the alloy of the present invention has a significantly shorter hydrogenation reaction time during activation than the nine conventional hydrogen storage alloys shown in the comparative example, and is extremely easy to activate. .

Using the above method, the relationship between pressure and temperature on hydrogen storage and release of each titanium multi-component hydrogen storage alloy was determined.
. 2B-' is expressed as the logarithm of the pressure - the reciprocal of the absolute temperature. I is the hydrogen absorption pressure, and the lower straight line is the hydrogen release pressure. In addition, the comparative example indicated by the dotted line is
FIG. 2 is a pressure-temperature diagram when a ternary hydrogen storage alloy having a composition of T IF m g, g N I o, 2 is used.

As is clear from FIG. 2, the alloy of the present invention has significantly improved hysteresis V as compared to the conventional hydrogen storage alloy shown in the comparative example. Furthermore, when comparing the alloy of the present invention and the alloy of the comparative example, there is almost no difference in the hydrogen release pressure and only the hydrogen storage pressure has decreased, and there is no significant deviation from the pressure characteristics of conventional alloys. There is also little need to change the design of the chemical reactor.

Table 1 shows the hydrogen storage capacity of each alloy obtained above.
o, 2: The amount of hydrogen storage is also large compared to sample-26).

Example 2 TIF・ in the same manner as in Example 1. , 8N1°, 1B
A (106"0.06) was manufactured and hydrogen absorption/desorption experiments were conducted to determine the relationship between hydrogenation reaction time and hydrogen absorption concentration for each alloy. As an example, TIF., 8r1
◎、1! Figure 8 shows the hydrogenation reaction curve upon activation for Sv0.06NbO,06, and the dotted line shows the comparative example 9, which is a ternary hydrogen storage system having a composition of TIF・0.8''011. This is a hydrogenation reaction curve during activation when an alloy is used.

As is clear from FIG. 8, the alloy of the present invention significantly shortens the hydrogenation reaction during activation and becomes extremely easy to activate, compared to the conventional hydrogen storage alloy of the comparative example.

Also, TI"0.8"Q, 15vO, 05NbO, 05"
Figure 4 shows the -H system expressed by the inverse relationship between the logarithm of pressure and the absolute temperature, where the upper straight line is the hydrogen storage pressure and the lower straight line is the hydrogen release pressure. The comparative example shown by the 119 dotted line is Ti
FIG. 2 is a pressure-temperature diagram when a ternary hydrogen storage alloy having a composition of F.o,s''., 2 is used.

As is clear from FIG. 4, the alloy of the present invention has significantly improved hysteresis UF compared to the conventional alloy of the comparative example.

Further, as in Example 1, the alloy of the present invention exhibits less change in hydrogen release pressure than conventional alloys, and only the hydrogen storage pressure is reduced, making it easy to design a metal hydride reactor.

In addition, Table 1 shows the hydrogen storage capacity of each alloy obtained above.
It also has a large amount of hydrogen storage compared to a26).

Example 8 In the same manner as in Example 1, IF・0.8”0.1!AO
,06"0.05 was manufactured and hydrogen absorption/desorption experiments were conducted.

The relationship between hydrogenation reaction time and hydrogen storage concentration was determined for each alloy. An example of this is TiF·o, s N t. ,
Figure 6 shows the hydrogenation reaction curve during activation for 2V (t. It is a hydrogenation reaction curve during activation when a ternary hydrogen @ storage alloy is used.

As is clear from FIG. 6, the alloy of the present invention significantly shortens the hydrogenation reaction during activation compared to the conventional hydrogen storage alloy of the comparative example, making activation extremely easy.

T I F @ o, s N I o, g V O, O
FIG. 6 shows the relationship between the logarithm of pressure and the reciprocal of absolute temperature for the F, Nbo, and o s-H systems.

As is clear from the sixth factor, the alloy of the present invention is 0.8
0.2, the hysteresis has been significantly reduced. Kutu Example 1
Similar to 2 and 2, the alloy of the present invention has less deterioration of the hydrogen release region than the conventional alloy, and only the water volume q and storage pressure are reduced, so the design of the metal hydride reactor is easy.

It has been found that the hydrogen storage capacity of these alloys is S~1.7 and jb9, which is higher than that of conventional alloys (1.4%).

[Brief explanation of drawings]

@1, 8.5 is a graph showing the relationship between the hydrogenation reaction time and hydrogen storage concentration during activation of the titanium multi-AIC hydrogen storage alloy according to the present invention and the conventional alloy. FIG. 2.4.6 is a graph showing the relationship between pressure and temperature on hydrogen storage and release of the titanium multicomponent thread hydrogen storage alloy according to the present invention and the conventional alloy. Applicant: Director of the Agency of Industrial Science and Technology Toyobo Co., Ltd.

Claims (1)

[Claims] (Titanium multi-component alloy for hydrogen**, characterized in that the general formula υ is represented by the amount of T ν・, NI, A, ml) [However,
In the formula, M is an element selected from niobium, vana, and v,4/conium, and l is a/l. Niobium, Rishimu, :! Baltic, manganese, sulfate,
PanaVn, Iw coum and tkhIl from rare earth elements
It shows nine elements selected from lI, and has a total of 0. (11~OS. ym(LO1~Q, 8t mm0.01~G,! e
a≦O9! (However, O is excluded) and 1.0≦(1-Ten+7+M11)≦1.1! and is an element that is radically different from A and 3). (To) Claims ■In paragraph 1, xmy4-g+
-Noto is a titanium multi-component hydrogen storage alloy where y≧1+1. (8) In the patent claim sin No. 1 (However, O is excluded) A titanium-based water III sake brewing alloy. (4) In patent claim osisgt, X W j
The number 11 is 1 and a is 1 and a is 1, and a is 1 and a is 1.
A titanium multi-component hydrogen storage alloy.