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Patent 2058054 Summary

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(12) Patent: (11) CA 2058054
(54) English Title: METHOD OF SEPARATING HYDROGEN ISOTOPE
(54) French Title: METHODE DE SEPARATION D'ISOTOPES DE L'HYDROGENE
Status: Deemed expired
Bibliographic Data
(51) International Patent Classification (IPC):
  • C01B 4/00 (2006.01)
  • B01D 59/32 (2006.01)
  • B01D 59/40 (2006.01)
  • H01M 8/00 (2006.01)
(72) Inventors :
  • KONISHI, SATOSHI (Japan)
  • HAYASHI, TAKUMI (Japan)
  • NARUSE, YUJI (Japan)
(73) Owners :
  • JAPAN ATOMIC ENERGY RESEARCH INSTITUTE (Japan)
(71) Applicants :
  • KONISHI, SATOSHI (Japan)
  • HAYASHI, TAKUMI (Japan)
  • NARUSE, YUJI (Japan)
(74) Agent: NORTON ROSE FULBRIGHT CANADA LLP/S.E.N.C.R.L., S.R.L.
(74) Associate agent:
(45) Issued: 2003-02-11
(22) Filed Date: 1991-12-19
(41) Open to Public Inspection: 1992-08-15
Examination requested: 1998-10-05
Availability of licence: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): No

(30) Application Priority Data:
Application No. Country/Territory Date
20912/1991 Japan 1991-02-14

Abstracts

English Abstract




A method of a hydrogen isotope is disclosed. This
method uses an isotope exchange reaction between water and
hydrogen, in which oxgen is electrochemically transferred from
water to be enriched with a heavy isotope to hydrogen to be
enriched with a light isotope, thereby permitting separation of
a hydrogen isotope with a largely reduced electric power
consumption, not requiring electric power supply, or with a gain
of electric power.


Claims

Note: Claims are shown in the official language in which they were submitted.



CLAIMS

1. A method of separating a hydrogen
isotope, by isotope exchange between water and
hydrogen, which comprises the steps of supplying
tritium-enriched water, which is produced in a
water-hydrogen isotope exchange reaction tower, to
one side of an oxygen ion conductive solid
electrolytic barrier membrane, the membrane being
oxygen permeable, which is provided with a water-
hydrogen exchanger, supplying hydrogen enriched
with a light isotope to the other side of the
oxygen ion conductive solid electrolytic barrier
membrane, and separating tritium by transferring
oxygen from the tritium-enriched water to the
hydrogen due to a difference of oxygen potential.


Description

Note: Descriptions are shown in the official language in which they were submitted.



METHOD OF SEPARATING HYDROGEN ISOTOPE
[FIELD OF THE INVENTION]
The present invention relates to a method of separating
a hydrogen isotope. More particularly, the present invention
relates to a method of separating a hydrogen isotope, which is
useful for separation, enrichment and removal of tritium in a
nuclear fusion reactor, upgrading of heavy water and enrichment
and removal of tritium in a heavy water reactor, separation and
removal of tritium in nuclear fuel reprocessing, and separation,
recovery and removal of tritium used in a usual test or
research, and further, separation of the other hydrogen isotope
except for tritium in a manufacture of heavy water.
[DESCRIPTION OF THE PRIOR ARTJ
The method of separating a hydrogen isotope based on
isotope exchange reaction between water and hydrogen is
advantageous in that the separation coefficient is high in the
state of equilibrium, permitting an achievement of a very high
separatiing performance using a single apparatus because of the
possibility of constituting a counter-current-type reaction
tower, and because chemically easy-to-handle substances such as
water and hydrogen are only used. While this is a hopeful
method for the manufacture of heavy water, removal and recovery
of tritium from water containing tritium oxides (hereinafter
tritium water), it requires a step of repeating to reduce water
to be enriched with a heavy isotope (for example, heavy hydrogen
- 1 -



~QS~Q~ 9~
~r tritium relative to light hydrogen) to hydrogen, and the
electric power consumption in electrolysis used fox this purpose
is one of the serious uroblems.
rr~ia.1 illustrates one of the embodiments of the
conventional method of separating tritium water based or_ the
combination of a counter-current-type isotope exchange reaction
tower and an electrolytic cell. As shown in rig. l, tritium
Water as a raw material is supplied through a raw material inlet
port (2) into an exchange reaction tower (1), enriched in the
reaction tower (1), and sent through an enriched water outlet
port (3) to an electrolytic cell (8). In the electrolytic cell
(8), tritium water is decomposed into hydrogen and oxygen
containing tritium at a high concentration, a part of hydrogen
is taken out as a product, and the remaining part is fed through
a hydrogen inlet port (4) into the exchange reaction tower (1).
On the other hand, oxygen, which contains tritium water vapor in
the original state, is sub,~edted to remove tritium water through
a water separator (10), and then sent into a hydrogen
recombinator ('1) by way of an oxygen feed line. After hydrogen
has tritium transfer into water in the exchange reaction tower
(1), hydrogen is sent through a hydrogen outlet port (5) into
the hydrogen recombinator ('I) where hydrogen is oxidized. A
part of thus-produced water is dumpted as depleted water or
cleaned water, and the remaining part is fed again through a
depleted water inlet port (6) into the exchange reaction tower
(1).
In such a conventional method, for example, oxidation



~0~~~3'.:~
of hydrogen and decomposition of water shoud be continuously
carried out to keep the flows of hydrogen and water to be
necessitated for isotope separation. The method is particularly
defective in that it reauires a large amount of electric power
for the decomposition of water, and this seriously results in
preventing the practical application.
The present invention has an object to provide a new
method which permits saving electric power consumption in the
step of repeating to reduce water to be enriched with a heavy
isotope to hydrogen, and does not even reauire electric power
for the decomposition of water.
Other objects, features and advantages of the present
invention will be apparent from the following description taken
in connection with the accompanying drawings.
[BRLEF DESCRIPTION OF THE DRAWINGS
Fig.l illustrates one of the embodiments of the
conventional method of separating tritium water based on the
combination of a counter-current-type isotope exchange reaction
tower and an electrolytic cell;
Fig.2 illustrates one of the embodiments of the present
invention in which an apparatus for transferring oxygen from
water to hydrogen is used;
Fig.3 depicts another embodiment of the present
invention in which a fuel cell as a recombinator is used; and
Fig.4 depicts further another embodiment of the present
invention in which an oxidizing/reducing agent is used as a
- 3 -

parameter for the reduction of water and oxidation of hydrogen. '
(DETAILED DESCRIPTION OF ThB EMBODIMENTS]
According to the present invention, it is possible to
separate a hydrogen isotope With almost no consumption of
electric power for the water decomposition step, or in some
cases, even with a gain of power.
The present invention is described below further in
detail with a separation of tritium from tritium water as an
example.
Fig.2 illustrates one of the embodiments in which an
apparatus simultaneously carrying out to convert water to
hydrogen and from hyarogen to water through transferrig oxygen
from watex to be enriched with a heavy isotope to hydrogen to be
enriched with a light isotope is combined with a Water-hydrogen
isotope exchange tower. More specifically, Fig.2 indicates a
concrete case where tritium water is enriched using an oxygen
ion conductive solid electrolytic cell as a water-hydrogen
converter. Tritium water as a raw material is supplied through
a raw material Water inlet port (12) to a water-hydrogen isotope
exchange reaction tower (11), enriched in this reaction tower
(11), and sent through an enriched water outlet port (13) to a
water-hydrogen exchanger (1'1). A part of the produced hydrogen
is taken out as a product, and the remaining part is sent back
through a hydrogen inlet port (14) to the exchange reaction
tower (11). Hydrogen has tritium transfer to water in the
exchange reaction tower (11), and is sent through a hydrogen
- a -



2~a~~~~
cutlet port (15) to the water-hydrogen converter (1Z), converted
into deleted water. The resultant depleted water is rejected
or supplied again through a depleted water inlet port (16) to
the exchange reaction tower (11). The hydrogen isotope in
tritium water is continuously separated during the process as
described above. The water-hydrogen converter (1?) supplies
water enriched with a heavy isotope on one side of an oxygen ion
conductive solid electrolytic barrier membrane (18), and
hydrogen enriched with a light isotope on the other side of
that. When a barrier membrane having a nature of permitting
permeation or' oxygen comes in contact with water on one side
thereof, and with hydrogen on the other side, the difference in
oxygen potential causes oxygen transfer from water to hydrogen.
This results in simultaneous conversions of oxygen from water to
hydrogen and from hydrogen to water. These conversions are
never mixed up each other because hydrogen isotopes are
seperated through the barrier membrance. Since these
conversions take place spontaneously to some extent, it is
usually unecessary to supply electric power, but oxygen may
forcedly be transferred to the hydrogen side by applying voltage
onto the both sides of the barrier membrance.
The electric power reauired for this transfer of oxygen
is far smaller than that reauired for conventional electrolysis.
It is thus possible to separate a hydrogen isotope and to
consume almost no electric power by the combination of the
isotope exchange reaction and a solid electrolytic cell.
The above-mentioned embodiment is involved in a method
- 5 -



In which electrolysis and recombination reaction are carried out
in a single apparatus. It is also possible to achieve those
with separate apparatuses.
Fig.3 shows a process of electrolyzing water with the
use of electric power produced when the recombination reaction
is utilized in generation or a fuel cell. In Fig.3, while an
isotope exchange reaction tower (11) is the same as shown in
Fig.2, hydrogen enriched with a light isotope is sent through
the hydrogen outlet port (15) to a hydrogen oxygen fuel cell
(19), and water enriched with a heavy isotope is sent through an
enriched water outlet port (13) to an electrolytic cell (20),
respectively. In the case where an oxygen ion conductive solid
electrolytic cell as shown in Fig.2 is used as that electrolytic
cell (20), the generating oxygen is so highly pure that water
and hydrogen are not contaminated by tritium even when supplying
the oxygen to the fuel cell (19). Oxidation of hydrogen in the
fuel cell (19) spontaneously ocurrs and proceeds, enabling to
take out electric power. The electric cell (20) is operated
with this electric power. Because the amount of water supplied
to the electrolytic cell (20) is almost eaual to that of
hydrogen supplied to the fuel cell (19), the amount of electric
generation of the fuel cell (19) serves the electric power
necessary for electrolysis, if electric loss is disregarded.
Furthermore, while decomposition of water in the electrolytic
cell (20) operated at a high temperature of about 900°C reauires
a voltage of about 0.9 V, the electro motive force or' the
hydrogen oxygen fuel cell (19) operated at the room temperature
- 6 -


~fl5~~~~
is about 1.2 V. It is therefore theoretically possible to
achieve a gain of electric power by appropriately setting these
operating temperatures.
Fig.4 depicts one of the embodiments in which energy is
tran3ferred through an aapropriate oxidation/reduction agent
from an oxidation step of rydrogen to a reduction step of water.
For example, a water gas equilibrium (H20 + CO = H2 + C02) is
now explained as follows: Hydrogen enriched with a light
isotope from the isotope exchange reaction tower (11) is sent
through the hydrogen outlet port (15) to a hydrogen oxidation
reactor (21), and water enriched with a heavy isotope is sent
through the enriched water outlet port (13) to a water reduction
reactor (22), respectively. As a water gas eauilibrium(H20 + CO
- H2 + C02) reaction is a reversible equilibrium reaction,
hydrogen and carbon dioxide are produced until the ea_uilibrium
is reached when water and carbon monoxide are supplied to the
water reduction reactor (22). On the other hand, water and
carbon monoxide are produced when hydrogen and carbon dioxide
are supplied to the hydrogen oxidation reactor (21).
By separating carbon dioxide anti carbon monoxide from those
reactors and circulating the same, it is possible to supply
water and hydrogen to the water-hydrogen isotope exchange
reaction tower (11) through oxidation of hydrogen and reduction
of water almost without energy consumption. In the practical
application of this embodiment, the steps of separating carbon
monoxide and carbon dioxide from water and hydrogen may be
omitted by using an oxygen ion conductive solid electrolytic
- 7 -


.:ell as shown in Fig.2 for the reactors (21) and (22).
It is needless to mention that various embodiments of
the present invention are possible in details of the
constitution thereof.
_ g _

Representative Drawing
A single figure which represents the drawing illustrating the invention.
Administrative Status

For a clearer understanding of the status of the application/patent presented on this page, the site Disclaimer , as well as the definitions for Patent , Administrative Status , Maintenance Fee  and Payment History  should be consulted.

Administrative Status

Title Date
Forecasted Issue Date 2003-02-11
(22) Filed 1991-12-19
(41) Open to Public Inspection 1992-08-15
Examination Requested 1998-10-05
(45) Issued 2003-02-11
Deemed Expired 2009-12-21

Abandonment History

There is no abandonment history.

Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Application Fee $0.00 1991-12-19
Registration of a document - section 124 $0.00 1993-05-21
Maintenance Fee - Application - New Act 2 1993-12-20 $100.00 1993-11-29
Maintenance Fee - Application - New Act 3 1994-12-19 $100.00 1994-11-16
Maintenance Fee - Application - New Act 4 1995-12-19 $100.00 1995-11-28
Maintenance Fee - Application - New Act 5 1996-12-19 $150.00 1996-11-26
Maintenance Fee - Application - New Act 6 1997-12-19 $150.00 1997-12-01
Request for Examination $400.00 1998-10-05
Maintenance Fee - Application - New Act 7 1998-12-21 $150.00 1998-11-23
Maintenance Fee - Application - New Act 8 1999-12-20 $150.00 1999-10-26
Maintenance Fee - Application - New Act 9 2000-12-19 $150.00 2000-10-20
Maintenance Fee - Application - New Act 10 2001-12-19 $200.00 2001-10-16
Maintenance Fee - Application - New Act 11 2002-12-19 $200.00 2002-10-18
Final Fee $300.00 2002-11-25
Maintenance Fee - Patent - New Act 12 2003-12-19 $200.00 2003-10-09
Maintenance Fee - Patent - New Act 13 2004-12-20 $250.00 2004-10-12
Maintenance Fee - Patent - New Act 14 2005-12-19 $250.00 2005-12-01
Maintenance Fee - Patent - New Act 15 2006-12-19 $450.00 2006-11-23
Maintenance Fee - Patent - New Act 16 2007-12-19 $450.00 2007-11-23
Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
JAPAN ATOMIC ENERGY RESEARCH INSTITUTE
Past Owners on Record
HAYASHI, TAKUMI
KONISHI, SATOSHI
NARUSE, YUJI
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
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Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Cover Page 2003-01-08 1 30
Representative Drawing 1999-06-30 1 6
Cover Page 1994-04-09 1 13
Abstract 1994-04-09 1 12
Drawings 1994-04-09 4 37
Claims 1994-04-09 1 26
Description 1994-04-09 8 269
Claims 2001-10-05 1 19
Representative Drawing 2002-05-28 1 5
Claims 2002-03-05 1 20
Prosecution-Amendment 2001-06-05 2 60
Prosecution-Amendment 2002-03-05 3 105
Correspondence 2002-11-25 1 38
Assignment 1993-03-01 13 452
Prosecution-Amendment 1998-10-05 2 53
Prosecution-Amendment 2001-10-05 3 59
Prosecution-Amendment 2001-11-05 2 58
Fees 1996-11-26 1 157
Fees 1995-11-28 1 167
Fees 1994-11-16 1 149
Fees 1993-11-29 1 156