JPS624432A - Gas purification device - Google Patents

Abstract

PURPOSE:To prevent the clogging of an adsorption tower by providing at least two adsorption towers having an adsorption layer in series, setting the operation temp. in the front tower higher than the rear tower and also providing a heat source for the regeneration of the adsorbent to the rear tower. CONSTITUTION:When gaseous H2 isotope contg. CH4 and C2H6 is passed through an ordinary-temp. adsorption tower 1a, steam and CH4 are adsorbed. The adsorbent of the adsorbent tower 1a is gradually saturated with stream and CH4 but CH4 firstly adsorbed by the difference of b.p. or the like is substituted with steam flowed-in thereafter and flowed in a low-temp. adsorption tower 2a from the adsorption tower 1a and readsorbed therein. In the regeneration of the adsorbent saturated with the impurities, CH4 adsorbed in the low-temp. adsorption tower is desorbed from the adsorbent only by returning it to the ordinary temp. from the temp. of liquid N2. Only tritium water is recovered in a regenerator 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a gas purification apparatus for purifying a fluid containing impurities.

[Technical background of the invention and its problems]

Nuclear fusion reactor (= in which hydrogen isotopes undergo a nuclear fusion reaction,
The energy released during this process is used to generate electricity, and a combination of deuterium and tritium is currently considered to be a promising fuel. However, if impurities are included in the fuel, the fusion reaction will not proceed quickly, so it is necessary to remove impurities and control the purity of hydrogen isotopes.Also, the presence of tritium in the gas after combustion In order to reuse deuterium, they need to be separated, and in particular when isotope separation is performed, the total amount of impurities must be kept below 1 ppm. Here, too, impurity removal is necessary. As methods for removing this impurity, low-temperature adsorption methods, multistage deep cooling methods, etc. have been devised, but in deuterium plants currently in operation,
Due to the simplicity of the equipment, low-temperature adsorption method (two-based impurity removal method) is often used.

The adsorption tower, which is the main part of the equipment using the above-mentioned low-temperature adsorption method, does not adsorb more than a certain amount of impurities, so it is generally constructed of multiple towers that are switched over in sequence to regenerate and reuse the adsorbed adsorbent. 1: It's like that. There are two methods of switching the timing: one method is to perform this switching for a certain period of time, and the other is to monitor the outlet gas concentration and perform it when the impurity concentration reaches a standard value.By the way, the adsorption tower used in a fusion reactor is , 77, so if there are many impurities with high boiling points, the impurities may condense in the adsorption tower and cause blockage of the adsorption tower. As a part of the adsorption tower is blocked, the flow of gas deteriorates and the pressure inside the adsorption tower gradually increases. The temperature may become dangerously high and the gas may flow backwards through the pipeline.To avoid this, a low-temperature condenser is installed in front of the adsorption tower to remove impurities with relatively high boiling points. However, it is technically difficult to construct an efficient condenser, and there is also a risk that the condenser itself will become clogged with condensed components.In addition, this measure will require additional space. Furthermore, since one system becomes more complex, it deviates from the concept of equipment used in a fusion reactor 1: the required low tritium inventory and compact design.

[Purpose of the invention]

The present invention has been made in view of these circumstances, and its purpose is to provide a gas purification apparatus that eliminates the problem of adsorption tower clogging mentioned above.

[Summary of the invention]

The present invention provides a flow path for a fluid containing impurities (i.e., at least two adsorption columns arranged in series for removing the impurities and filled with an adsorbent having a preferable equilibrium with the impurities; This is a gas purification device in which the operating temperature in the rear column is set higher than that in the rear column, and in particular, the rear column does not have a heat source for regenerating the adsorbent.

〔Effect of the invention〕

According to present invention 1, when gas containing impurities passes through a gas purification device, the impurities are adsorbed by the adsorbent in the adsorption tower to obtain purified gas, but at this time, impurities with a high boiling point are The adsorbent installed in the front adsorption tower, which has a relatively high operating temperature, adsorbs it, and impurities with a low boiling point are adsorbed by the adsorbent installed in the rear adsorption tower, which has a low temperature. At this time, impurities with a low boiling point are also adsorbed by the adsorbent installed in the front adsorption column, but the selectivity of adsorption due to differences in boiling points, etc. Impurity 1: is thus displaced, flows out from the front adsorption tower, and is readsorbed by the adsorbent provided in the rear adsorption tower.

For this reason, impurities with high boiling points are removed by the adsorbents installed in the front adsorption tower (2), so impurities with high boiling points do not flow into the rear adsorption tower (2), and therefore, the adsorbents installed in the rear low-temperature adsorption tower Impurities with a high boiling point will no longer condense between the adsorbents in the adsorption layer where carbon has been rubbed, and there will be no possibility of clogging of the adsorption tower.

Furthermore, according to the present invention, the following effects can be obtained.

Since the impurities adsorbed in the rear low-temperature adsorption tower have low boiling points, it is possible to regenerate the rear low-temperature adsorption tower at room temperature. Since no heat source is required, the mechanism is simplified (=
, heating of the adsorbent 1: Deterioration caused by heating can also be prevented.

In addition, the reduction in the heating surface is due to leakage of tritium from the wall surface (
Hydrogen isotopes have the property of permeating through various materials, and the amount thereof greatly depends on temperature. ), which is advantageous in terms of safety.

Further I: After impurity removal, tritiated impurities must be separated from tritium and other components, and tritium must be recovered, and the impurities must be separated at the time of impurity removal. 1; Therefore, the treatment in the process of separating tritium from the other components becomes easier and more effective.

[Embodiments of the invention]

Embodiment 1 of the present invention: FIG. 1 is a schematic configuration diagram of a related gas purification apparatus. In the purification tower for removing impurities from the hydrogen isotope gas, 1atlb is a normal temperature adsorption tower filled with an adsorbent, and 2a12b is a low temperature adsorption tower filled with an adsorbent. The low-temperature adsorption towers are thermostats 16a and 1.
Inside 6b (77K) t: It is stored, and the flow G of the gas to be purified is from piping 13-pulp 5-adsorption tower 1a-valve 7-piping 17
--Pulp 6 → Adsorption tower 1b → Valve 8/ /Valve 9 - Suction 5tf tower 2a - Pulp 11 → Piping 14 -
1 valve 10→adsorption tower 2b→valve 12/, valve 5 to 121=therefore, switching is performed.

This switching operation is initiated by a signal from a controller, not shown, at a certain time or when a breakthrough of the adsorption layer occurs. In addition, the adsorption tower can be regenerated by using the adsorption tower at room temperature (= then using the adsorbent regenerator 3 and the heater 1
5a or 15b, the liquid nitrogen in the low-temperature adsorption tower (or thermostatic chamber 16a or 16b is drained, and the adsorbent regenerator 3 is used to perform the process at room temperature. (Although the : is not shown, this purification equipment is comprised of a system for cooling the adsorption tower, which is started by a signal from the controller, and a system for transporting gas.

A case will be described in which the hydrogen isotope purification apparatus configured as described above contains water vapor as an impurity with a high boiling point and methane as an impurity with a low boiling point. First, when hydrogen isotope gas containing these gases passes through the adsorption tower 1a at room temperature, water vapor and methane are adsorbed. The adsorbent in the adsorption tower 1a gradually becomes saturated with water vapor and methane, but due to differences in boiling points, etc., the adsorbed methane
Abbreviation for water vapor that flows in later = Therefore, it is replaced, and the adsorption tower 1a
It then flows into the low-temperature adsorption tower 2a, where it is re-adsorbed. In addition, the adsorption agents in adsorption tower 1a and adsorption tower 2a do not need to be the same; for adsorption tower 1a1, it is desirable to use one that is highly selective in adsorption for impurities with high boiling points. For example, when removing water vapor and methane, use adsorption tower 1al-molecular sieve 3 (trade name), adsorption tower 2ac molecular sieve 5
When A (trade name) is used, only water vapor is removed using three molecular sieves, and methane is removed using molecular sieve 5A.

In addition, regeneration of each adsorbent saturated with impurities is performed using a regenerator as described above, but in the case of regeneration of three molecular sieves that have adsorbed water vapor, a heater
00°C 1: Heating is required, but the adsorbed methane is desorbed from the adsorbent simply by returning it from the liquid nitrogen temperature to room temperature.In this way, the regenerator 3 has water vapor, i.e. Only tritiated water is recovered, which can be easily separated into nitritium and oxygen by electrolysis.Tritiated methane is recovered in the regenerator 4, which is oxidized using a catalyst. The tritiated water is then electrolyzed together with the tritiated water obtained in the regenerator 3 mentioned above. By doing this, during the oxidation reaction of tritiated methane, the product tritiated water is is removed in advance, it is possible to prevent the yield of the oxidation reaction from decreasing.

Therefore, in the gas purification apparatus according to the embodiment of the present invention,
Since the adsorption tower 1a is at room temperature, there is no problem of water vapor solidifying and clogging the adsorption tower, and there is no need to provide a condenser. It is also advantageous to reduce the number of points where tritium can leak.In the above embodiment, two adsorption towers are installed in parallel.
The same applies to the case of 3 or more towers and 3 or more columns in parallel.

[Brief explanation of the drawing]

Embodiment I of the present invention: FIG. 1 is a configuration diagram of a related gas purification apparatus.

Claims (1)

[Claims] In a purification column having an adsorbent layer provided in a flow path of a fluid containing two or more types of impurities to remove the impurities and filled with an adsorbent having a preferable equilibrium with the impurities, the adsorption columns are arranged at least in series. 1. A gas purification apparatus comprising two columns, the operating temperature of the front column is set higher than that of the rear column, and the rear column is not provided with a heat source for regenerating an adsorbent.