JPS59177117A - Separation of hydrogen-helium - Google Patents

Abstract

PURPOSE:To separate hydrogen by allowing the same to permeate a separation membrane, by forming partial pressure difference in both sides of the separation membrane by sending a gaseous mixture containing hydrogen and helium to the single side of the separation membrane comprising a transient metal or an alloy thereof on a gas pervious support. CONSTITUTION:A continuous membrane having a thickness of about 1mum or less comprising a transient metal such as Fe, Cr, Mn, Ni, Ag, Pd or Ti or an alloy thereof is formed on a gas pervious support such as a ceramic porous membrane by sputtering. This continuous membrane is used as a separation membrane and a gaseous mixture containing hydrogen, an isotope thereof and helium is sent to the single side of said membrane while the supply side of the membrane is pressurized to form partial pressure difference in both sides of the membrane and hydrogen and the isotope thereof are permeated to the opposite side of the membrane more fastly as compared with helium to separate the same. As the above mentioned continuous membrane, a SUS membrane comprising an Fe-Cr-Ni type alloy is suitably used from a standpoint of cost and capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a membrane separation method for separating hydrogen and helium containing isotopes.

The demand for energy continues to increase year by year, and various energy sources are being explored to meet this demand, with nuclear fusion being one of the most promising.

This utilizes the following nuclear fusion reaction between deutorium and tritium.

'H 10'H-Now' He + n According to this, when tritium in ip reacts with deuterium, approximately 100 million K ayl of energy is generated.

However, the conversion rate of this reaction is at most 10%, and the fusion waste gas contains large amounts of unreacted raw materials deutorium and tritium, which must be separated and recovered from the helium produced.

One of the separation methods is membrane separation, which requires less energy for separation and is easy to operate. However, hydrogen, its isotopes, and helium are all gases with small molecular weights, and the difference in molecular weight is small, so membrane separation is generally used. It is a gas that is difficult to separate.

Therefore, the present invention was achieved as a result of intensive research aimed at realizing a membrane separation method for hydrogen and helium containing isotopes.

That is, the present invention is a method for separating hydrogen (including isotopes) and helium using a separation membrane in which a continuous membrane of a transition metal or its alloy is formed on a gas-permeable support.

As the gas permeable support used in the present invention, as long as it is gas permeable, Ivf (/C) may be used, but is not limited to an organic polymer film, an organic porous material, or an inorganic porous material. It will be done.

Among these, organic or inorganic porous materials with high gas permeability are preferably used.

Among these, inorganic porous membranes such as ceramic porous membranes, glass porous membranes, stainless steel porous sintered bodies, etc., which are materials that can withstand high temperatures as gas-permeable supports, are preferably used because the membranes are metal and can withstand high temperatures.

Membrane separation at high temperatures generally has the advantage that gas permeability increases as the temperature rises, so the amount of permeation increases at high temperatures, or that a portion of high-temperature waste gas can be treated without cooling it. be.

The shape of the support is determined depending on the shape of the separation module, and can take various shapes such as a flat membrane, a tubular shape, and a hollow fiber.

The transition metal used in the present invention has an atomic number of 21 to 30.3.
9-48.57-80 elements such as Fe, Cr
, Mn, Ni, Ag, Pd, Ti, etc., and these can also be used in various alloys such as Fe-
Cr-Ni, Ni-Mo, Ni-Cr-
Fe-Mo-C.

It can also be used.

In the present invention, a continuous thin film layer of the above-mentioned metal or alloy is formed on the above-mentioned gas-permeable support to form a separation membrane. Methods for forming the thin film layer include sputtering method, vapor deposition method, ion blating method, etc. Conventionally known physical deposition method (PVD)
Among these, sputtering and ion grating methods are preferred because they provide good adhesion between the metal film and the gas-permeable support.

Furthermore, in the process of forming a metal film, the metal may be partially oxidized, but as long as the oxide is stable, it can be used as is as a separation film.

The separation method of the present invention is carried out on the transition metal film, and its thickness K is not limited to %, but it is preferably as thin as possible without causing defects, and the film thickness is preferably 1 μm or less, preferably is less than or equal to 1oooX.

From the viewpoint of cost and performance, the transition metal film of the present invention is an Fe-based alloy such as Fe-Cr-Ni alloy Rul! Membranes are preferably used.

The separation method involves sending a gas mixture containing hydrogen, its isotopes, and helium to one side of the separation membrane (the supply side), and quickly allowing the hydrogen and its isotopes to permeate through the other side of the membrane (the permeation side), rather than the helium. To separate.

Separation techniques include applying pressure to the supply side of the membrane, reducing pressure to the permeate side of the membrane, or creating a partial pressure difference on both sides of the membrane by flowing gas such as argon as a carrier gas. Separation membranes are used not only to separate nuclear fusion waste gas, but also to separate ordinary hydrogen and helium mixed gases, such as helium and helium, by taking advantage of its high separation properties between hydrogen and helium.
Not only can it be used to separate hydrogen from natural gas containing hydrogen, but also from mixed gases containing gases with molecular weights larger than hydrogen and helium, such as methane and argon, due to its excellent hydrogen permeability. It can also be used for hydrogen separation.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples in any way.

Example 1 Formation of a metal thin film layer A metal thin film layer made of 5US304 and having a thickness of 100× was formed on the surface of a bisphenol A-polycarbonate film having a thickness of 300 μm. The metal thin film layer is made of 5US304 plate (
Ar gas pressure 5X10 with a thickness of 3 mm) as a target
It was formed by DC magnetron sputtering at Torr. Input power is 2W/c per unit area of target
+(, and the distance between the target and the polycarbonate film serving as the substrate was 156 m.

The separation performance of this membrane is shown in Table IK.

H21,8,7 D214.4 T2O,53 2 He <xio (below the measurement limit) 2 Ne <XIO (but (below the j-determined limit)) The gas permeability coefficient was measured by the following method.

Transmission coefficient measurement diagram - shows the cell part of the IK measurement device. The cone is made from two glass tubes with a real flat 7 lunge (1).
The sample membrane (2) was held between the flanges with an O-ring. The effective area of the sample membrane is 9.5 crI. A windowless G-M counter (3) for measuring the tritium permeation rate is connected to the downstream side of the permeation cell, and a glass ampoule (4) pre-filled with a certain amount of tritium is inserted to the upstream side. did.

The permeation rate of each gas was measured by the Time-1ag method. The permeation rate of non-radioactive gas is measured by the flow method, and the amount of permeation and the pumping rate using an ionization vacuum gauge are determined by the capillary tube and the pumping rate by the ionization vacuum gauge.
It was determined using two ionization vacuum gauges.

The permeation rate of tritium gas was measured in a closed system, and G-M
The concentration was measured with a counter. The permeation rate is (Torr
-cc/sec), and the unit of the transmission coefficient calculated from this is expressed in od/sec.

Stream side 2 A mixed gas containing 2 vol% each of deutorium, protium, and helium, with the remainder being argon, was flowed onto the surface of the SUS membrane of Example 1, and the gas mixture was flowed onto the surface of the SUS membrane of Example 1 on the opposite side of the membrane (permeation side).
Flow the K-argon carrier gas.

Deutorium and protium were detected on the 10-minute pass side, but helium was not detected.

[Brief explanation of drawings]

Figure 1 shows a gas permeation rate measuring device. 1 represents a cone flat flange, 2 represents a sample membrane, 3 represents a G-M counter, and 4 represents a gas ampoule. 0゛＠l m A a E 6″′″ 21, Agent Patent Attorney Mae 1) Jun Hiroj, ;'7,
l・/Group-1

Claims (1)

[Claims] 1. Hydrogen (including its isotopes) and helium are separated using a separation membrane in which a continuous membrane of a transition metal or its alloy is formed on a gas-permeable support. Hydrogen-helium separation method. 2. The hydrogen-helium separation method according to claim 1, wherein the continuous membrane is a sun membrane.