JPS58167410A - Peparation of argon - Google Patents

Abstract

PURPOSE:To prepare argon in high recovery ratio, by washing and regenerating a nitrogen adsorbent with a desorbed O2 gas from an oxygen adsorbent, passing the resultant product Ar gas through the oxygen adsorbent and the nitrogen adsorbent one after another, and washing and regenerating the adsorbents. CONSTITUTION:A mixed gas of Ar with O2 and N2 from an air separation apparatus is introduced from a pipe 1 into a buffer tank 2, pressurized in a compressor 3 and then introduced through an inlet valve (4a) into the first adsorption cylinder (5a) of an adsorption apparatus 5 to adsorb the N in a nitrogen adsorbent (5a-MS) and O in an oxygen adsorbent (5a-CS) and recover the Ar gas, which is then fed through an outlet valve (7a), pipe 8 and flow control valve 9 to a part to be fed. On the other hand, an inlet valve (4b) and outlet valve (7b) of the second adsorption cylinder (5b) after completing the adsorption stage are closed to open a discharge valve 10 and a valve 11 and reduce the pressure to almost atmospheric pressure. The O and N gas in the second adsorption column (5b) are desorbed under reduced pressure and discharged to the outside. A purging valve (13b) is then opened to introduce part of the Ar through a pressure reducing valve 14 and a pipe 15 into the second adsorption cylinder (5b) to wash and regenerate both adsorbents. The Ar gas is then released to the outside. When the Ar gas in the released gas is in a given amount, the gas is returned through a return valve 16 and a pipe 17 to the tank 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing argon from a gas containing argon by using a suction process.

Generally, in the production of argon OIa, a line element with a relatively large argon content is extracted from an air cryogenic separator, this is rectified in a crude argon column to produce crude argon, and the O oxygen in this crude argon is deoxidized. This is then carried out by rectification in a high-purity argon column. However, this O method has drawbacks such as requiring a large amount of production equipment at public expense, requiring complicated continuous operation, insufficient argon recovery rate, and being uneconomical in terms of energy.

In addition, as an argon production method other than the above,
A method of introducing oxygen and nitrogen OtS gas into an adsorption tower filled with 2*0* adhesive in an unpressurized state, and removing nitrogen and oxygen by the adsorption tower to obtain argon. 5
No. 1-122273 Publication However, since the 1CO method regenerates the adsorbent by desorption by decompression operation using a vacuum pump, it is necessary to reduce the piping resistance, making the piping, valves, etc. larger. This has the disadvantage of increasing equipment costs. In addition, if there is a leak during the transfer, the degree of vacuum will decrease, the attachment and detachment performance will decrease, and the product Albo/[11 and (
b) Yield decreases. Furthermore, two argon pressurizers are used to suck the mixed gas into one adsorption tower and to force-feed 1M argon, which has the disadvantage of increasing equipment costs and requiring time and effort for maintenance.

This invention was made in view of the above circumstances, and the purpose is to provide a method for producing argon that is simple in equipment, easy to operate, consumes little energy, and has a high yield of argon. That is.

Hereinafter, Jin's invention will be explained in detail with reference to the drawings.

The drawings show an example of the method for producing argon according to the present invention.

In a certain type of air removal separation 1KII, there is a device that maximizes the amount of oxygen collected and also collects product oxygen. The waste gas Ifi from this air separation device is a mixed gas whose main components are nitrogen, oxygen, and argon, and most of the argon #1 in the raw air is contained in this waste gas. For example, this waste gas with a composition of 15% argon, 4% oxygen, and 4% nitrogen may be used as the raw material gas in pipe 1 or in buffer tank 2.
will be introduced in Then, it is pressurized to about 51 cm by the compressor 3, passes through the large mouth valve No. 4, and goes to the first adsorption tower 5 m and the curtain g.
150 liters of adsorption equipment consisting of a Wk adsorption tower sb is introduced into an adsorption tower 51. The molecular sieves that adsorb ore nitrogen are full at the inlet of lk deposition towers 5& and 5b (nitrogen adsorption column Sa-MS Oyohi 5b-M8), and the exit 11Kt
! It is filled with carbon sheeps that adsorbs oxygen (oxygen adsorption cylinder!5a-O8,!1)-051), and a partition plate of 8m is made of a porous air-permeable plate to prevent both adsorbents from mixing. , 6b are provided. The raw material gas introduced into the SZa deposition tower s1 under pressure is first introduced into the nitrogen adsorption column 5a-M.
Nitrogen is adsorbed and removed by the 8-mole hour error sheet, and then oxygen is adsorbed and removed by the carbon sheet cloth of the oxygen adsorption column 5m-011 to become the product argon, which is then released.
□It is sent to the supply destination via the flow valve 71, the pipe 8, and the flow rate adjustment valve 9.

At this time, the other No. 21 & landing tower 5b is in the stage of regenerating the adsorbent. That is, after the adsorption stage is completed, the inlet valve 4b
, the outlet valve 7b is closed, the discharge valve 10 and the valve 11 are opened, and the pressure of the second adsorption tower 5b is reduced to approximately atmospheric pressure. As a result, the oxygen and nitrogen Fi adsorbed on the carbon sheep and its regular sieves in the second adsorption tower 5b are depressurized, and the discharge valve 101 is removed together with the residual gas in the salt 5b.
), pipe 12 and valve 11 to be released to the outside. At this time, the carbon sieves at the outlet of the second adsorption tower sb are used to wash the molecular sieves at the oxygen company inlet that have been desorbed, and the regeneration of the molecular sieves is preceded by ξ. Then, the purge valve 13b is opened, and a part of the product argon passes through the pressure reducing valve 14 and the pipe 15, and is transferred to the second adsorption tower 5b.
The carbon sieves and molecular sieves are introduced into the second absorption tower sb from the negative outlet, where the carbon sieves and molecular sieves are washed and desorbed. The waste gas consisting of il, nitrogen and argon desorbed from force-bond and molecular sieves is
From the second adsorption tower 5b through the discharge valve 10bl, pipe 12, valve 1
Although it is released as it is, it decreases first compared to o**5tFi oxygen filtration in Ogas gas, which is released as soon as regeneration occurs. As mentioned above, this is due to the cleaning of the molecular sheath.
This is because it is preceded by the detachment test volume from carbon sheeps. When the amount of electron in the waste gas becomes small and the content of argon reaches a predetermined content, the valve 11 is closed and the waste gas is returned to the buffer tank 2 via the valve 16 and pipe 17. Ru. As a result, the waste gas consisting essentially of argon and 1kIlc is returned to the raw material system, and the loss of argon is kept to a minimum for forging.

In this way, the regeneration of the II adsorption tower 5b is completed, and then it is repressurized with product argon and becomes ready for the next adsorption. Then, product argon is continuously obtained by the following two adsorption towers 5a and 5blH which are switched over.

In this argon production method, each adsorption tower I
Molekie two sheeps that adsorbs nitrogen on the inlet side of sa%sb, outlet 111KII! Since the carbon sheeps adsorbing element was filled, when regenerating these a-adhesives, the pressure was reduced from the carbon sheeps,
Since the molecular sieves are washed to remove N by the wk element, the amount of product argon used for washing is reduced, and the loss of product argon is reduced. In addition, by arranging the molecular sieves at the negative entrance, the desorption from the molecular sieves occurs first, as described above, so that most of the nitrogen is removed from the 1 &
a, 5b, and only argon and oxygen are present in the adsorption path.@Because a small amount of M element is allowed to be mixed into the product argon (for example, when #'! is used as a bath gas argon) ) Carbon Sheeps product It is no longer necessary to completely wash and desorb with argon, the amount of argon for washing can be reduced, and most of the argon for washing can be returned to the return valve 16.
Since the argon is returned to the buffer tank 2 through the pipe 17, loss of argon is extremely small. Furthermore, all of the power is provided by one 4-compressor, so l
#c The lid is simple, equipment costs are low, and maintenance is easy.

In the above embodiment, one adsorption tower is filled with molecular sieves and carbon sheep, but the present invention is not limited to this. The adsorbent may be packed in a separate MOA cylinder and these adsorption cylinders can be connected with piping to form an adsorption tower.The adsorbent is not limited to molecular sieves and carbon sheeps, but can also be used as an adsorbent. Agents such as zeolites and other O-oxygen adsorbents can also be used.

As explained above, according to the argon production method of the present invention, the recovery rate of argon is increased, the production equipment is simplified, the equipment cost is low, continuous operation is easy,
Maintenance is also easier.

In addition, unlike conventional rectification methods, there is no need for repeated cooling and heating, and there are advantages such as low energy consumption and excellent salmon processing properties.

[Brief explanation of the drawing]

The drawings are from ζO! FIG. 2 is a system diagram showing an example of a method for producing o-argon. 3... pressure m machine, luster... sucking pupil, 5 &...
... 1 absorption tower, 5b ... 2nd adsorption tower, 6. Partition plate, ] 1 ... Valve, 14 ... Pressure reducing valve, 1
6...Return valve, 17...Pipe. Derived from Japan M Soto Co., Ltd. γ, -)

Claims (1)

[Claims] A mixed gas containing argon, oxygen, and nitrogen as the main components is used as the raw material gas, and this raw material gas is pressurized to produce oxygen filled with #L elementary absorption shield from the phoneme & bulk cylinder filled with Suragi adsorbent. In the step of obtaining product argon by sequentially flowing it through the argon gasket, and during the regeneration of the above-mentioned argon cylinder, the pressure of 0x11ky11tlIJ is reduced, nitrogen and oxygen are desorbed, and argon is removed from the argon gas cylinder.
In the process of washing and regenerating the nitrogen absorption tube with m elementary gas, a part of the argon from θ is sequentially passed from the elementary absorption tube to the IIF absorption tube in the TL, and the #II cumulative absorption tube and! ! I'm washing the 1-element adsorption cylinder.
It is assumed that argon is produced by the above steps ①, ＠, 6, which is the process of extracting plums and releasing the waste gas depending on the 'thll content in the cleaning waste gas or returning it to the welfare raw material gas system. Method of producing argon.