U.S. patent number 3,922,872 [Application Number 05/547,073] was granted by the patent office on 1975-12-02 for iron titanium manganase alloy hydrogen storage.
This patent grant is currently assigned to The United States of America as represented by the United States Energy. Invention is credited to James J. Reilly, Richard H. Wiswall, Jr..
United States Patent |
3,922,872 |
Reilly , et al. |
December 2, 1975 |
Iron titanium manganase alloy hydrogen storage
Abstract
A three component alloy capable of reversible sorption of
hydrogen having the chemical formula TiFe.sub.1.sub.-x Mn.sub.x
where x is in the range of about 0.02 to 0.5 and the method of
storing hydrogen using said alloy.
Inventors: |
Reilly; James J. (Bellport,
NY), Wiswall, Jr.; Richard H. (Brookhaven, NY) |
Assignee: |
The United States of America as
represented by the United States Energy (Washington,
DC)
|
Family
ID: |
24183245 |
Appl.
No.: |
05/547,073 |
Filed: |
February 4, 1975 |
Current U.S.
Class: |
34/416; 62/46.2;
420/581; 423/248; 502/324; 95/116; 148/DIG.153; 376/151; 420/900;
423/644 |
Current CPC
Class: |
F17C
11/005 (20130101); C01B 3/0031 (20130101); C22C
14/00 (20130101); H01M 4/383 (20130101); Y10S
420/90 (20130101); Y10S 148/153 (20130101); Y02E
60/10 (20130101); Y02E 60/32 (20130101) |
Current International
Class: |
F17C
11/00 (20060101); C01B 3/00 (20060101); C22C
14/00 (20060101); H01M 4/38 (20060101); F17C
011/00 () |
Field of
Search: |
;62/48 ;75/175.5,134F
;252/471 ;423/248 |
References Cited
[Referenced By]
U.S. Patent Documents
|
|
|
2798806 |
July 1957 |
Jaffee et al. |
3508414 |
April 1970 |
Wiswall, Jr. et al. |
3516263 |
June 1970 |
Wiswall, Jr. et al. |
|
Primary Examiner: O'Dea; William F.
Assistant Examiner: Capossela; Ronald C.
Attorney, Agent or Firm: Carlson; Dean E. Belkin;
Leonard
Government Interests
BACKGROUND OF THE INVENTION
The invention described herein was made in the course of, or under
a contract with the U.S. Atomic Energy Commission.
Claims
What is claimed is:
1. A three component alloy capable of reversible sorption of
hydrogen having the chemical formula TiFe.sub.1.sub.-x Mn.sub.x
where x is in the range of about 0.02 to 0.5.
2. The method of storing hydrogen comprising contacting a solid
alloy of TiFe.sub.1.sub.-x Mn.sub.x where x is in the range of
about 0.02 to 0.5 with gaseous H.sub.2 at a pressure above the
dissociation pressure of the hydride.
3. The method of claim 2 in which the pressure of H.sub.2 during
contacting is at least twice the dissociation pressure of the
hydride for the temperature during contacting.
4. The method of claim 3 in which the pressure of H.sub.2 during
contacting is about ten times the dissociation pressure of the
hydride for the temperature during contacting.
Description
Hydrogen is a potential fuel for various types of power sources,
such as fuel cells, internal combustion engines, gas turbines, etc.
It has two great advantages over fossil fuels, it is essentially
nonpolluting and it can be produced using several all but
inexhaustible energy sources, i.e., solar, nuclear and geothermal.
However, a major problem is the difficulty encountered in its
storage and bulk transport. Conventional storage methods, i.e.,
compression and liquefaction, do not appear to be practical in this
context.
A possible solution to the problem lies in the use of a metal
hydride as a hydrogen storage medium. Several hydrides are of
interest but the material most near to practical application is
iron titanium hydride, which can be synthesized through the direct
union of hydrogen with the intermetallic compound, FeTi.
Our U.S. Pat. Nos. 3,508,414 and 3,516,263 disclose methods and
apparatus for utilizing iron-titanium alloys to store hydrogen by
the formation of hydrides.
One difficulty which has been discovered in the use of
iron-titanium alloys for hydrogen storage is the effect of the
presence of oxygen in the alloys in small amounts. For example, it
has been discovered that the presence of oxygen in the amount of
7000 ppm in commercially available iron-titanium reduced
substantially the maximum hydrogen that could be stored and the
equilibrium dissociation pressure was increased. This had the
effect of increasing the costs involved in storing hydrogen by the
use of these alloys.
SUMMARY OF THE INVENTION
It has been discovered that the addition of manganese to the
intermetallic alloy FeTi in certain specific amounts not only
increases the amount of H.sub.2 which can be stored and at a lower
pressure but also has the effect of compensating to a significant
extent for the presence of oxygen, permitting significant increases
in the amounts of hydrogen which can be stored under more
convenient and economical pressures.
In accordance with a preferred embodiment of this invention there
is provided a three component alloy capable of reversible sorption
of hydrogen having the chemical formula TiFe.sub.1.sub.-x Mn.sub.x
where x is in the range of about 0.02 to 0.5.
There is also provided, in accordance with another preferred
embodiment of this invention, a method of storing hydrogen
comprising contacting gaseous hydrogen with a solid alloy of
TiFe.sub.1.sub.-x Mn.sub.x where x is in the range of about 0.02 to
0.5.
It is thus a principal object of this invention to provide an
improved alloy for the chemical storage of hydrogen.
Another purpose is to provide an improved method for the storage of
hydrogen.
Other objects and advantages of this invention will hereinafter
become obvious from the following description of preferred
embodiments of this invention.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1 and 2 show curves illustrating the H.sub.2 storage
characteristics of alloys incorporating the principles of this
invention and comparing them with similar alloys not incorporating
this invention.
DESCRIPTION OF THE BACKGROUND EMBODIMENTS
An alloy in accordance with this invention may be prepared by
melting granules or small ingots of Fe, Ti, and Mn in an arc or
induction furnace within an inert atmosphere followed by
cooling.
The cooled alloy, in order to be utilized for the storage of
hydrogen is comminuted or granulated and then activated by
outgassing at high temperature (300.degree. C) and exposing to
H.sub.2 for a short time followed by outgassing again and cooling
under hydrogen with about 1 atmosphere pressure.
In order to form the hydride the activated alloy is exposed to
H.sub.2 at a pressure usually 10 atmospheres above dissociation
pressure at that temperature, due to hysteresis type effects. The
hydriding pressure should for best results be at least twice the
dissociation pressure because of the already mentioned hysteresis
effect.
EXAMPLES
An alloy was prepared with the composition (A) of FeTi and the
dissociation pressure-composition isotherms for this alloy are
shown in FIG. 1. The H.sub.2 dissociation pressure of this alloy
can be seen from the curve at 40.degree. C to be at least 7.2
atmospheres and reaches 25 atmospheres at the maximum H.sub.2
concentration. A similar alloy (B) was prepared in which some of
the iron was displaced by Mn and had the formula TiFe.sub..7
Mn.sub..3. The dissociation pressures for this alloy at the same
temperature, as shown in FIG. 1, range from 0.42 to 9 atmospheres
for the same amount of stored H.sub.2 as in alloy (A). In the
drawing, the atom ratio, H/M is defined as the ratio of atoms of
hydrogen to total atoms of metal.
It was found that for other temperature conditions the presence of
Mn displacing some of the iron additionally made it possible to
increase the amount of H.sub.2 which could be stored as well as
reducing the dissociation pressure. Curves C in FIG. 2 shows
isotherms for a FeTi alloy at 55.degree. and 70.degree. C while
curve D shows the isotherm at 61.degree. C for the composition
TiFe.sub.0.8 Mn.sub.0.2. Not only does alloy D have a lower
dissociation pressure but in addition H.sub.2 storage capacity was
increased by about 10 percent by weight. This is shown by the upper
limits of the curve.
* * * * *