JPS61138519A - Membrane separation process of hydrogen isotope - Google Patents

Abstract

PURPOSE:To improve isolation performance for hydrogen isotope by using a film body formed of a shape memory alloy prepd. by sintering Ni-Al powder and executing separation by permeation at near a martensitic transformation temp. of said film body. CONSTITUTION:A film body 1 formed of a shape memory alloy prepd. by sintering Ni-Al powder is fixed to a clamp 2, and a gaseous mixture of hydrogen with tritium to be isolated is introduced into a feed tank 3. Then, a permeation cell 6 is heated by an electric furnace 5 at a specified temp. corresponding to the martensitic transformation temp. of said film body 1. The hydrogen- tritium gaseous mixture 4 is allowed to permeate the film body by sucking using vacuum, thus gaseous tritium is isolated. As the result, the isolation performance for hydrogen isotope is improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is directed to the process of recovering tritium, a hydrogen isotope contained in the exhaust gas emitted from a nuclear fusion reactor, and reusing it as fuel, as well as environmental problems. The present invention relates to a membrane separation method for hydrogen isotopes that can be expected to be used in the process of recovering tritium gas through electrolysis of tritium-containing water.

[Conventional technology]

Conventionally, water distillation, cryogenic separation, thermal diffusion, metal membrane permeation, and laser methods are known as methods for separating this type of hydrogen-tritium mixed gas.

Among these, the metal membrane permeation method utilizes the fact that the permeation rate of hydrogen isotopes through a gold iI4 membrane differs depending on the type of isotope.
, J, Nucl, SC1, TechnoJ , ,
17,436 (1980).

This membrane separation method is easy to operate and is promising as an energy-saving technology.

[Problem that the invention seeks to solve]

However, even with palladium alloy membranes, which are currently considered optimal, a high temperature of around 400° C. is required for efficient separation, and countermeasures against leakage of tritium gas are required for operation at high temperatures.

Therefore, it is desired to develop a permeable membrane that exhibits a separation coefficient comparable to that of a palladium alloy membrane even at room temperature, or a permeable membrane that exhibits a large separation coefficient at as low a temperature as possible.

[Means for solving problems]

The present invention aims to satisfy these demands, and its gist is a membrane separation method in which hydrogen isotope mixed gas is permeated and separated by a membrane body;
Formed with shape memory alloy prepared by υ powder sintering,
There is a method for membrane separation of hydrogen isotopes, which is characterized by permeation and separation at a temperature near the martensitic transformation temperature of the membrane.

〔Example〕

(1) The Ni-Al alloy used for the film body of the shape memory alloy prepared by powder sintering was first mixed with 50% Nl powder and M powder.
After mixing at a ratio of 0% (weight), it was filled into a quartz glass tube and sintered on a sintering port under vacuum at a temperature of 700°C for 1 hour to prepare an alloy powder, and then: N to this alloy powder! Add powder to Ni j 73%, 7vI+ 27%
(2) After preparing the components, a sample (Nl-Al prisoner) molded at a molding pressure of 686M was heated to 1250"C for 1
After being sintered for a period of time, it is quenched in ice water to form a thermoelastic martensitic structure, which causes a shape memory phenomenon.
The (Ni-AJ(B)) membrane body has a diameter of 10U,
The thickness is IUL.

+1) Hydrogen isotope separation The prepared membrane body (1) is fixed to the clamp (2) as shown in the figure, and the hydrogen-tritecum mixed gas (4) to be membrane separated is introduced into the supply tank (3). Then, the permeation cell (6) is heated by the electric furnace (5) to a predetermined temperature corresponding to the martenite transformation temperature of the membrane (1), and in this state vacuum suction:; 4) is permeated through the membrane body (1) to separate tritium gas.

In addition, (Table 1) shows that the gas that permeates through the membrane body and is collected at a specified temperature is quantitatively analyzed using a Nitepra pump.
The amount of tritium gas concentrated on the supply side was determined based on the ratio of the separation coefficients determined for each time period, and was shown together with other data.

NI OJ4 0.98 204151a9
2.22270 3fL6! 1LO24, 2B
d, e) 0.50 378 QJ33 1.968
U8316 0J6 1.00 20 13J
116 1.20245 51.2 2L2
λ42a) Nl-person 1 (A) 0J35 1.01
20 9.93 a61 1.77220
&39 465 1.80b) Ni-Al(B) 0/5 0.99 20 3.
31 164 2.02310 1.98 CI
CJ90 220Cn 3e
) Pd-Ag O,504001,37
0 2.12 (Jl) Unquenched alloy (bl Quenched alloy (C) Pd-25Ag, membrane-I-1-% (d) Saw y 'f /L' membrane (elmol Cm
As a result, if a material with a high specific metal density was prepared by powder sintering, even a material made of single Ni showed a separation factor comparable to that of a Pd-Ag alloy in room temperature tests, but Ni-AI ( g) For alloys, as shown in Table 11,
At around the martensitic transformation temperature (310°C), Pd-A
It showed a separation factor about 20 times that of g-alloy.

〔Effect of the invention〕

As described above, the present invention has a membrane body made of a shape memory alloy prepared by sintering Ni-Al powder, and permeation separation is performed near the martensitic transformation temperature of the membrane body, so hydrogen isotope separation performance is improved. can be improved.

[Brief explanation of drawings]

The drawings are explanatory diagrams for use of the present invention. (1)...Membrane body. December 8, 1980 Applicant: Masao Matsui, Manabu Ueno
Yutaka Kami 2 Kitamatsu
Kowa-〇Royoshi Production: 0

Claims (1)

[Claims] In a membrane separation method in which hydrogen isotope mixed gas is permeated and separated by a membrane, the membrane is formed of a shape memory alloy prepared by sintering Ni-Al powder, and the membrane is permeated and separated at a temperature near the martensitic transformation temperature of the membrane. A membrane separation method for hydrogen isotopes.