JPS59147618A - Process for regenerating adsorbent in high degree purification apparatus for gas - Google Patents

Abstract

PURPOSE:To perform reasonably the regeneration of a low temp. adsorbent in a low temp. adsorption column of a high degree purification apparatus of gas by specifying the compsn. of the gas to be purified in the low temp. adsorption column and simultaneously by regulating the regeneration temp. to the ordinary temp. CONSTITUTION:For the purification of gas such as H2, He, Ar, etc. to a very high purity, the concn. of impurities contained in the gas is reduced by passing the gas through an ordinary temp. adsorption cylinder, and purified further by passing through a low temp. adsorption column packed with a low temp. adsorbent such as zeolite and cooled to deep temp. by liquefied N2 etc. The regeneration of the low temp. adsorbent is performed by passing purified gas heated to the room temp., but the regeneration may be performed more efficiently with less consumption of purified gas for the regeneration and heating energy if the content of moisture and CO2 in the feed gas to be purified in the low temp. adsorption column are both <=1ppm.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for regenerating an adsorbent in a low-temperature adsorption column used for high-purity purification of gas.

Generally, gases such as H2, Hθ, Ar, etc. are used with high purity (e.g. 99%
．． 9999% or more), the concentration of impurities contained in the gas is reduced by passing it through a room-temperature adsorption column filled with molecular sieves, etc., and then using synthetic zeolite, etc. as the raw material gas for the low-temperature adsorption column. For example, it is filled with molecular sieves, activated carbon, or a mixture of both, and deep cooled (for example, -19
The gas is placed in a low-temperature adsorption cylinder that is suspended at 6°C, and further adsorbs and removes impurities to produce high-purity gas.

The adsorbent in the normal-temperature and low-temperature adsorption column is regenerated after performing the refinement for a certain period of time.

Two of the above-mentioned room temperature and low temperature adsorption columns are provided and are alternately regenerated and used, but the room temperature adsorption column is regenerated by well-known heating and purge gas circulation.

In addition, the adsorbent in the low-temperature adsorption cylinder generally uses purified gas at 20%
The temperature of the adsorbent is increased by heating it to 0 to 650°C and passing it through a low temperature adsorption cylinder. It is regenerated by raising the temperature to 150-500°C and removing adsorbed substances.

By the way, the adsorbent in the low-humidity adsorption column is cooled to below -190°C, so heating it to 150 to 00°C will reduce the temperature difference between the adsorption V''JJ production time and the temperature difference. is 3
The temperature increases from 50 to 500'C. For this reason, (1) there is a large loss of heating energy, and a device for heating the gas is required.

■ Because purified gas is used for heating, 4”0 of purified gas is used for heating.
It's a big loss.

(2) Since the thermal stress of the low-temperature adsorption device is large, the materials that can be used are limited, and advanced processing techniques are required, and the cost increase due to special supplies for the equipment is large.

There were some drawbacks.

As a result of conducting extensive research to solve the above-mentioned problem, the present inventor has discovered that H20 and CO in the raw material gas can be passed through a low-temperature adsorbent to adsorb and remove impurities to obtain a high-purity gas. If the content is less than 1 p (by), the impurities of N2 and It has been found that it can be easily removed and regenerated.

The present invention was not completed based on the above knowledge, and its gist (well, in the method of regenerating an adsorbent in a low temperature adsorption column in a gas daytime purification device The content of moisture and carbon dioxide in the raw material gas to be removed to obtain high purity (9) gas is set to be less than 11 positive,
The present invention provides a method for regenerating an adsorbent in a gas high-purity gas equipment, characterized in that the low-temperature adsorbent is maintained at the lowest temperature during regeneration.

The method of the present invention will be specifically explained below as two examples of regenerating the adsorbent in a low-temperature adsorption cylinder in a high-purity H2 gas production device with a degree of 1fi9.

The adsorption breakthrough in the regeneration test of the low-temperature adsorption column and the determination of the amount of adsorption after regeneration were carried out as follows.

Adsorption breakthrough: pulverize 6g of adsorbent into 20-24 meshes,
It was filled into a cylindrical adsorption tube with an inner diameter of 10.5 mfi.

The adsorption column, which had a filling height of about 181 cm and was filled with crushed adsorbent, was maintained at -196°C with liquid nitrogen.

In this state, the raw material H2 gas (inlet gas) shown in the actual example described below was introduced into the adsorbent, and adsorption breakthrough was defined as the time when the concentration of nitrogen gas at the outlet became the same as the concentration of nitrogen gas at the inlet.

Adsorption amount after regeneration: The same device as used for adsorption breakthrough was filled with the regenerated adsorbent and maintained at -196°C with liquid nitrogen.
i pnm % CO2 < H2 gas containing 1ppIl? The changes in the concentration of nitrogen gas at the inlet and outlet of the adsorbent were determined for four rivers, and the amount of nitrogen gas adsorbed when the outlet nitrogen concentration reached 25p was determined.

Practical Example 1 Molecular Sieve 5Al (commercially available product, manufactured by Union Showa KK) was used as an adsorbent, and the degree of water content in the raw material gas was varied. This resulted in adsorption breakthrough. This breakthrough adsorbent was regenerated at various temperatures, and the amount of adsorption after regeneration was measured. The results are shown in Table 1. Actual Example 2 Using the same adsorbent as in Example 1, CO2 in the raw hydrogen gas was
The adsorption breakthrough was achieved by changing the concentration, and the adsorption agent that had broken through was regenerated by changing the temperature, and the amount of adsorption after regeneration was measured. The results are shown in Table 2.

As is clear from Actual Examples 1 and 2 in Table 2, N20 is used as a raw material.
, it can be seen that when Ht gas containing 1 ppm or less of CO2 is used, the adsorbent that has broken through with this raw material gas is completely regenerated at room temperature.

Example 3 Same adsorbent as Example 1? Used, 1.7 raw materials, 7 in gas
7) The adsorption breakthrough was achieved by varying the N2/02 concentration by 4 degrees, and the adsorbents that had adsorption breakthrough were regenerated under the following conditions]! l! After regenerating the adhesive, the number of layers attached was measured. The results are shown in Table 3.

Table 3 Adsorbents that have undergone adsorption breakthrough using raw material hydrogen gas with N20 and CO2 of less than ipp+i, respectively, have the following characteristics: When the temperature of the adsorbent σ is set to room temperature, the gas passing through during regeneration replaces the wound. You can see that it is played almost without any problem.

Example 4 Using an active 1 momme as an adsorbent, this raw material scum'f which does not adsorb or break through with the raw material H2 scum containing the impurities shown in the table below.
What is the regeneration temperature and flow time of the regeneration gas? The adsorption capacity of the regenerated (P6 adhesion) was measured by regenerating the above-mentioned breakthrough adsorbent.The results are shown in Table 4.

In addition, in the above examples, all embryo purity [2 gas purification equipment Y
I have described the regeneration method of low-temperature adsorbent in 1-10.
Similar results were obtained in the regeneration of low-temperature adsorbents such as , Ar, etc.

As described above, the method for regenerating a high-purity gas purification type adsorbent according to the present invention involves passing a low-temperature adsorbent through 1. By passing N20 and P in the raw material gas to be purified into high-purity gas as regeneration gas, almost complete regeneration can be achieved. Therefore, the loss of heating energy accompanying regeneration is reduced, there is no need for heat equipment to heat the regenerated gas, and there is no need for adsorption.
This method has many advantages, such as there is little difference in temperature between tJ and the temperature during regeneration, so thermal stress is small, and there is no need to improve the quality of the equipment or the grade of processing.

Claims (1)

[Claims] In a method for regenerating an adsorbent in a low-temperature adsorption column in a high-purity gas purification device, a raw material gas having a moisture content and a carbon dioxide content of less than I1111n, respectively, is introduced into a low-temperature adsorption column to generate high-purity gas, and during regeneration, A method for regenerating an adsorbent in a high-purity gas purification device, the method comprising retaining the low-temperature adsorbent in a blockage state.