JPH07148419A - Method for concentrating oxygen isotope - Google Patents

Abstract

PURPOSE:To concentrate simply and stably <17>O existing in an extremely poor ratio in nature to a high concentration keeping equilibrium in a distillation column. CONSTITUTION:The distillation operation to distill an oxygen compound containing <16>O, <17>O, and <18>O components which is loaded in a distillation column and the extraction operation to extract the top fraction and the bottom fraction in the column in a specified ratio while a raw material being supplied so that the total amount of the extract becomes equal to that of the raw material supplied are carried out alternately to concentrate the <17>O component at the bottom. After the concentration ratio between the <17>O component and the <18>O component at the bottom becomes equal to the concentration ratio between them in the raw material, the bottom fraction recovery operation in which the bottom fraction of an amount equal to that of the raw material supplied is recovered while the raw material being supplied and the top fraction extraction operation in which the top fraction of an amount equal to that of the raw material to be extracted is extracted while the raw material being supplied are repeated alternately, and the distillation operation for the total reflux distillation of the raw material in the column is conducted between the recovery operation and the extraction operation.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for enriching oxygen isotopes, in which oxygen isotopes ¹⁶ O, ¹⁷ O and ¹⁸ O are enriched by fractionating oxygen or oxygen compounds. The present invention relates to a concentration device and a concentration method suitable for concentrating extremely small amounts of ¹⁷ O and ¹⁸ O.

[0002]

2. Description of the Related Art In recent years, oxygen isotopes ¹⁷ O and ¹⁸ O, which have begun to be used for diagnosis of adult diseases, have a very low natural abundance ratio,
For example, oxygen compounds such as water H ₂ O and nitric oxide NO are condensed and produced by distillation.

For example, with respect to water H ₂ O, H ₂ ¹⁶ O, H ₂ ¹⁷ O and H ₂ ¹⁸ O exist as its isotopes, and the natural abundance ratios of each are ¹⁶ O, ¹⁷ O and ¹⁸ O. Equal to the natural abundance, H ₂ ¹⁶ O is 99.76%, while H ₂ ¹⁷ O
Is 0.0374% and H ₂ ¹⁸ O is 0.203%.

By the way, water currently used commercially
In the distillation method, a water distillation column cascade consisting of 9 stages
Are manufactured by using the
Always complex, and 98.4% H per day₂ ¹⁸1 for O
5cc and 20% H₂ ¹⁷It is possible to produce 5cc of O
The produced H is very low in concentration efficiency. ₂
¹⁷O or H₂ ¹⁸The cost of O becomes very high.

For this reason, the present applicant has a very simple method of using ¹⁷ O
We have proposed a semi-batch / semi-continuous method for concentrating water (Japanese Patent Application No. 3-227).
072). This is because when the raw material containing three kinds of ¹⁶ O component, ¹⁷ O component and ¹⁸ O component was distilled, the boiling point temperature was
Utilizing the fact that ¹⁷ O component lower than ¹⁶ O component and higher than ¹⁸ O component is concentrated in the middle position of the distillation column, and the top fraction and the bottom fraction are withdrawn at a predetermined ratio while the top fraction and the bottom fraction are withdrawn.
^{The 17} O component is concentrated, and the content ratio of the ¹⁷ O component and the ¹⁸ O component in the intermediate position is maintained substantially equal to the composition ratio of the raw material, and the side stream distillation in which the ¹⁷ O component is concentrated is obtained from the intermediate position. I try to extract the minutes as a product.

[0006]

However, although the intermediate position where the ¹⁷ O component is concentrated can be determined theoretically, it differs from the theoretical value in the actual production process due to various external factors and changes in conditions. Since the concentration of ¹⁷ O component at the position and the position where the ¹⁷ O component is concentrated move up and down during the processing operation, in order to match the position with the theoretical position, the extraction ratio of the top fraction and the bottom fraction should be adjusted. There is a new problem that it is difficult to maintain the equilibrium state due to complicated control that is finely adjusted, and the side stream fraction enriched with ¹⁷ O component cannot be stably recovered. It was Therefore,
INDUSTRIAL APPLICABILITY The present invention makes it possible to easily concentrate ¹⁷ O having a very small natural abundance to a high concentration, and further to maintain the equilibrium state in the distillation column and stably concentrate the ¹⁷ O component. Is an issue.

[0007]

[Means for Solving the Problem] To solve this problem
In the present invention, the oxygen isotope¹⁶O,¹⁷O and¹⁸Acid containing O
The raw materials are oxygen or oxygen compounds, and each isotope is supplied to the distillation column.
A method for concentrating oxygen isotopes for concentrating a body, comprising: a) a distillation operation for distilling a raw material packed in a distillation column;
The top fraction and bottom fraction are withdrawn while feeding
When the total amount of extraction is equal to the amount of raw material supplied
Alternately with the taking-out operation, b) Withdrawing the overhead fraction with respect to one total withdrawal amount of the above-mentioned taking-out
Intake ratio is included in raw materials¹⁶Less than composition ratio of O component
And the ratio of the amount of the bottom fraction extracted is included in the raw material.
Be¹⁸Set it higher than the composition ratio of the O component and keep it at the bottom of the tower.
Ru¹⁷With O component ¹⁸Those in which the concentration ratio of O component is included in the raw materials
Repeat each of the above operations until the concentration ratio of¹⁷O component and¹⁸The concentration ratio of the O component at the bottom is the concentration of the raw material
After the ratio becomes almost equal, while supplying the raw materials¹⁷O component
as well as¹⁸The bottom fraction in which the O component is concentrated is used as the raw material supply amount.
Column bottoms collection operation to collect only a large amount and do not supply raw materials.
Rattle¹⁶The overhead fraction enriched with O component is equal to the raw material supply amount.
Alternately repeat withdrawal operation of top fraction
Along with performing the recovery operation and the extraction operation, distillation
A distillation operation for distilling the raw material packed in the column is performed, and d)¹⁷O component and¹⁸Concentration ratio of the bottom of O component
In order to maintain the ratio equal to
Included in the raw materials supplied¹⁶The amount of O component during the sampling operation
Contained in the raw materials supplied to¹⁷With O component¹⁸Total of O component
That the raw material supply amount is set to be slightly higher than the amount
Characterize.

[0008]

According to the present invention, as a raw material, for example, when nitric oxide NO containing oxygen isotopes ¹⁶ O, ¹⁷ O and ¹⁸ O in a natural isotope composition is supplied to a distillation column to perform a distillation operation, The ¹⁶ O component having a low boiling point is concentrated on the top side of the column, the ¹⁸ O component having a high boiling point is concentrated on the bottom side of the column, and the ¹⁷ O component is concentrated at an intermediate position.

Next, the top fraction and the bottom fraction are not
The withdrawing operation of removing one and the distillation operation are alternately performed.
At this time, remove the overhead fraction withdrawal amount from the total withdrawal amount.
The ratio is included in the raw material ¹⁶Set smaller than the composition ratio of O component
The rate of withdrawal of bottoms is not included in the raw materials.
Ru¹⁸Since it is set larger than the composition ratio of O component,¹⁷
The peak position of the O component concentration moves to the bottom of the distillation column
of¹⁷The O component concentration increases.

By repeating this operation, ¹⁷ O
Ingredients are concentrated to 14.4% and ¹⁸ O to 78.48%, and the concentration ratio (1: 5.45) is contained in the raw materials.
0374: 0.2039 = 1: 5.45), the bottom fraction recovery operation of collecting the bottom fraction while supplying the raw material in an amount equal to the raw material supply amount and the top fraction while supplying the raw material While repeating the overhead fraction withdrawing operation of withdrawing only the amount equal to the raw material supply amount, while performing each batch processing of the recovering operation and the withdrawing operation, the raw material charged in the distillation column is subjected to total reflux distillation. Perform a distillation operation.

At this time, the amount of ¹⁶ O component contained in the raw material supplied during the recovery operation is set to be slightly larger than the total amount of ¹⁷ O component and ¹⁸ O component contained in the raw material supplied during the extraction operation. Each raw material supply amount is set.

Therefore, from the bottom of the tower, it is contained in the raw material.
¹⁷ O component and ¹⁸ O component are recovered in the composition ratio,
From the top of the tower, the ¹⁶ O component contained in the raw material is obtained in a state of being concentrated to almost 100%, and the concentration ratio of the ¹⁷ O component and the ¹⁸ O component at the bottom of the tower is always the concentration ratio of each component contained in the raw material. Therefore, the bottom fraction enriched with the ¹⁷ O component can be stably recovered.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a flow sheet showing an example of an oxygen isotope enrichment apparatus for carrying out the method of the present invention. The present apparatus is a series type two-stage apparatus in which a first distillation column 1 and a second distillation column 2 are connected in series. It uses a distillation method.

In the first distillation column 1,¹⁶O,¹⁷O and¹⁸O
As the oxygen or oxygen compound to be contained, for example, nitric oxide N
Raw material supply pipe 3 for supplying O, N¹⁶O (¹⁶O component) is rich
An overhead fraction discharge pipe 4 for extracting the condensed overhead fraction;¹⁷
O (¹⁷O component) and N¹⁸O ( ¹⁸Tower with concentrated O component)
A column bottoms discharge pipe 5 for withdrawing bottoms is attached.
It

The first distillation column 1 is composed of a large diameter column 1a and a small diameter column 1b which are connected via a pipe (not shown). The large diameter column 1a and the small diameter column 1b have a cross-sectional area ratio of, for example, 100: 1
When the diameter of the large diameter tower 1a is 1 m, the diameter of the small diameter tower 1b is set to 10 cm, and the theoretical plate number is, for example, 560 theoretical plates for the large diameter tower 1a and 5 for the small diameter tower 1b.
It is set at 40 theoretical stages. The raw material supply pipe 3 is connected to the position of the 10th theoretical plate from the bottom of the large diameter column 1a, and the overhead fraction discharge pipe 4 for discharging the overhead fraction of the large diameter column 1a is N ¹⁶ O. The bottom fraction discharge pipe 5 that is connected to the storage tank 7 and discharges the bottom fraction of the small diameter column 1b is connected to the drain 8 and the intermediate product storage tank 9 via the valve V ₅ .

The distillation column 1 is provided with a condenser and a reboiler (both not shown) at the top and bottom of the large diameter column 1a and at the top and bottom of the small diameter column 1b, respectively. ing. The distillation column 1 is filled with packing such as Dickson, McMahon, and Helipack, and
It is thermally insulated from the outside of the distillation column 1 and maintained at a temperature near the boiling point of nitric oxide NO (for example, −153 ° C.).

In the first distillation column 1, N ¹⁶ O, N ¹⁷
A plurality of gas detectors 10 for detecting the concentration distribution of O and N ¹⁸ O are provided at predetermined intervals in the vertical direction.
The detection result of 0 is input to the control device 11 that controls the opening and closing of the valves V ₃ , V ₄ and V _{5 provided} in the pipes 3, 4 and 5.

The control device 11 sets the opening and closing timings and flow rates of the valves V ₃ , V ₄ and V ₅ based on the detection result of the gas detector 10 and the output signal of the setting device 11a. and consists of a switch 11b for opening and closing the valves V _3, V ₄ and V ₅ based on the detection signal of the flow rate detector Q _3, Q ₄ and Q ₅ interposed to each pipe, to the control unit 11 , Valves V ₃ , V ₄ and V ₅
A predetermined program for controlling the opening and closing of at a predetermined timing is stored, and a raw material supply amount, a top fraction withdrawal amount, a bottom fraction withdrawal amount, etc. are set.

In the second distillation column 2, a raw material supply pipe 12 for supplying the NO stored in the intermediate product storage tank 9 as a raw material and a top distillate discharge pipe 1 for extracting concentrated N ¹⁶ O.
3 and a column bottoms discharge pipe 14 for extracting concentrated N ¹⁸ O
And a sidestream distillate discharge pipe 15 for extracting concentrated N ¹⁷ O is attached.

The inner diameter of the second distillation column 2 is selected to be equal to that of the small diameter column 1b of the first distillation column, and the theoretical plate number is set to 1100 theoretical plates. The supply pipe 12 and the sidestream distillate discharge pipe 15 are connected to a position half the height of the distillation column 2, that is, a position 550 theoretical plates from the lower end. Further, the column top fraction discharge pipe 13 is connected to the N ¹⁶ O storage tank 7, and the column bottom fraction discharge pipe 14 is connected to the N ¹⁸ O storage tank 16.
The sidestream distillate discharge pipe 15 is connected to the N ¹⁷ O storage tank 17.

A condenser and a reboiler (both not shown) are provided at the top and bottom of the second distillation column 2, respectively. The second distillation column 2 is filled with packing such as Dixon, McMahon, and Helipack, and is thermally insulated from the outside of the distillation column 2 to a temperature near the boiling point of nitric oxide NO (for example, -153 ° C.). ) Is maintained.

Further, the second distillation column 2 is provided with a gas detector 18a for detecting the concentration of N ¹⁷ O at the position where the sidestream distillate discharge pipe 15 is attached, and the maximum fraction point of N ¹⁷ O is determined. For detection, a plurality of gas detectors 18b, 18b for detecting the concentration distribution of N ¹⁷ O in the distillation column 2 are provided at predetermined intervals in the vertical direction.
Valve V ₁₂ interposed in 3,14 and 15, V _13, V ₁₄
And V ₁₅ are input to the control device 19 which controls opening and closing.

The control unit 19 based on the detection result of the gas detector 18a and 18b, and the setter 19a for setting the opening and closing timing and the flow rate of each valve V ₁₂ ~V _15, the output signal of the setting device 19a and consists of a switch 19b based on the detection signal of the flow rate detector Q ₁₂ to Q ₁₅ interposed in the pipes 12 to 15 for opening and closing the valve V ₁₂ ~V _15, to the control device 11, the valve V with a predetermined program is stored which controls the opening and closing of the ₁₂ ~V _15, the raw material supply amount, the amount sampling overhead fraction, amount, etc. sampling TosokoTome content is set.

Next, an example of a method for enriching an oxygen isotope using the above-described enrichment device will be described with reference to Tables 1 and 2.
Tables 1 and 2 show the results of simulating the operating processes of the first distillation column and the second distillation column, respectively. In this example, NO of the natural isotope composition is used as a raw material for the first distillation column 1
After performing the first distillation in step 1, the bottom fraction obtained by the first distillation was further distilled in the second distillation column 2 to perform the second distillation.

When performing the primary distillation, the first distillation column 1
Distill operation to distill the filled raw material and do not supply the raw material.
The top fraction and bottom fraction of the waste glass are totally removed at the specified extraction ratio.
Withdrawal operation to take out so that the taken amount becomes equal to the raw material supply amount
Alternately. At this time, the total amount of one sampling operation
Included in the raw material is the ratio of the overhead distillate withdrawn¹⁶O component
Of the bottom fraction of the bottom fraction.
Included in raw materials¹⁸Set larger than the composition ratio of O component
And at the bottom of the tower¹⁷With O component ¹⁸The ratio of the content of O component is
The above operations are repeated until the composition ratio of the raw materials becomes approximately equal.

Specifically, first, 56540 mol of nitric oxide NO was charged into the first distillation column 1 from the raw material supply pipe 3, and -153
A total reflux distillation operation is performed at around ℃ to make the isotope concentration distribution approximately steady. Next, while further supplying 3000 mol of NO, a withdrawal operation was performed in which the top fraction and the bottom fraction were withdrawn at a predetermined withdrawal ratio and the total withdrawal amount became equal to the raw material supply amount (Table 1: Batch After the process numbers 1 to 12) and the withdrawal operation are completed, the total reflux distillation operation is performed while the withdrawal operation of the next process is performed. The ¹⁷ O component concentration of this bottom fraction reaches about 3 to 14%, which is sufficiently higher than the natural abundance ratio and has utility value, so that it is recovered in the product tank 20 via the drain 8. It

[0027]

[Table 1]

The ratio of the withdrawal amount of the overhead fraction to the total withdrawal amount in one withdrawal operation is set smaller than the composition ratio of N ¹⁶ O contained in the raw material (natural abundance ratio: 99.76%) (for example, from 99.30 to 99.63%) and the ratio of the amount of the bottom fraction withdrawn is the composition ratio of N ¹⁸ O contained in the raw material (natural abundance ratio: 0.2
Since 04%) greater than the set has (e.g. from 0.3 to 0.7 percent), the peak position of the concentration of N ¹⁷ O is the concentration of N ¹⁷ O in the mobile and the column bottom under the distillation column becomes higher.

N ^{17 at the} bottom of the first distillation column 1
When O reaches, for example, about 14.4% in mole fraction, and N ¹⁸ O reaches, for example, 78.48% in mole fraction, the concentration ratio of N ¹⁷ O and N ¹⁸ O is contained in the raw material NO. After approximately matching the ratio (molar fraction ratio of about 1: 5.45), N ¹⁷ O and N ¹⁸
A bottoms fraction collecting operation for collecting the bottoms fraction enriched with O as an intermediate product in the intermediate product recovery tank 9, and a tops fraction withdrawing the tops fraction enriched with N ¹⁶ O into the storage tank 7. The extraction operation is alternately repeated, and a distillation operation of performing total reflux distillation of the raw material packed in the first distillation column 1 is performed between each batch processing of the recovery operation and the extraction operation (Table 1: Batch processing number). 13-).

At this time, N at the bottom of the tower¹⁷O component and N¹⁸
Maintain the concentration ratio of O component equal to the concentration ratio of raw material
Included in the raw materials supplied during the bottoms fraction recovery operation.
Be ¹⁶The amount of O component is supplied during the overhead distilling operation
Contained in raw materials¹⁷With O component ¹⁸Slightly higher than the total amount of O component
The raw material supply is set so that

In this example, first, while supplying 5 moles of the raw materials, a bottoms fraction collecting operation of collecting 5 moles of a bottoms fraction in which N ¹⁷ O was concentrated to 15.4% was performed, and then a total reflux distillation operation was performed. Perform (Batch processing number 13). Then, while carrying out the supply of 1829.62 mol of the raw material, the column top fraction withdrawing 1829.62 mol of the N ¹⁶ O concentrated overhead fraction is extracted, and then the total reflux distillation operation is again carried out (batch processing number 14).

By this column bottom fraction recovery operation, ¹⁷ O component and
¹⁸ with O component is recovered is enriched remain composition ratio contained in the raw material, from overhead obtained in a state in ^{which 16} O component contained in the raw material is concentrated to near 100% as possible, ¹⁷ in the bottom Since the concentration ratio of the O component and the ¹⁸ O component is always kept equal to the concentration ratio of each component contained in the raw material, the column bottom fraction enriched with the ¹⁷ O component is stably recovered. After that, the same collection and extraction operations are repeated (batch processing number 15
~), Intermediate product storage tank 9 using the bottom fraction as an intermediate product
Store in.

Then, when a predetermined amount or more of the side stream distillate of the first distillation column 1 is stored in the intermediate product storage tank 9, the secondary distillation is started. In the secondary distillation, NO stored in the intermediate product storage tank 9 is used as a raw material to fill the second distillation column 2 and a total reflux distillation operation is performed. Then, the bottom fraction is supplied while supplying the raw material until the concentration of N ¹⁷ O at the mounting position of the sidestream fraction discharge pipe 15 of the second distillation column 2 reaches a preset target mole fraction (eg 99.08%). A portion is withdrawn with an amount equal to the amount of raw material supplied, and the total reflux distillation operation is performed again until the next withdrawal operation is performed.

Specifically, first, the NO stored in the intermediate product storage tank 9 is supplied to the second distillation column 2 to the second distillation column 2.
Charge 100 moles and perform total reflux distillation operation at around -153 ° C to make the isotope concentration distribution approximately steady. Next, after performing an extraction operation of extracting 200 mol of the bottom fraction while further supplying 200 mol of NO, a total reflux distillation operation was performed (Table 2: batch treatment Nos. 1 to 8), and a sidestream distillate discharge pipe 15 N ¹⁷ O at the mounting position of is concentrated.

When the maximum fraction point of N ¹⁷ O moves up and down with respect to the mounting position of the sidestream fraction discharge pipe 15, the discharge amount of the top fraction and the bottom fraction is adjusted, Adjust so that the maximum fraction point of N ¹⁷ O coincides with the mounting position of the sidestream distillate discharge pipe 15 (batch processing number 9 to 10).

[0036]

[Table 2]

[0037] Then, after the N ¹⁷ O in the mounted position of the side Nagar fraction discharge pipe 15 is concentrated to a target value, the side Nagar fraction recovered N ¹⁷ O to recover the side Nagar fraction enriched as a product The operation and the withdrawal operation for withdrawing the overhead fraction and the bottom fraction are alternately repeated, and the raw materials with which the second distillation column 2 is filled are charged during the batch processing of the recovery operation and the withdrawal operation. Perform a distillation operation of total reflux distillation (Table 2: Batch processing numbers 11 to 11).

In this example, N ^{17 was} supplied while 5 mol of the raw material was supplied.
After performing a recovery operation for recovering 5 mol of a side-stream fraction in which O is concentrated to 99.04%, a total reflux distillation operation is performed (batch processing number 11). Next, 27.27 mol of the raw material was supplied to the top fraction for 4.25 mol (15.59%) and the bottom fraction for 23.02 mol (8
(4.41%) After performing the extracting operation, the total reflux distillation operation is performed again (batch processing No. 12).

Thereafter, by repeating similar collecting operation and extracting operation (batch processing number 13-), about 99% is obtained.
The concentrated N ¹⁷ O can be easily recovered, and the overhead fraction and the bottom fraction enriched with N ¹⁶ O and N ¹⁸ O each having a concentration of 99.9% or more are used as by-products in large amounts. Can be produced. Then, finally, hydrogen is added to N ¹⁶ O, N ¹⁷ O, and N ¹⁸ O to decompose them into ammonia and water, respectively, and then thermally decompose to remove hydrogen to decompose into nitrogen and oxygen. Concentrations of oxygen isotopes ¹⁶ O ₂ , ¹⁷ O ₂ and ¹⁸ O
You can get ₂ .

In the description of the embodiments, the case where NO is used as the raw material has been described, but the present invention is not limited to this, and oxygen O ₂ and other arbitrary oxygen compounds such as carbon monoxide CO are distilled at low temperature. The present invention can also be applied to the case where water is distilled off or when water H ₂ O or the like is distilled under reduced pressure. Further, the concentration of N ¹⁷ O in the first distillation column and the second distillation column can be arbitrarily set according to the abundance ratio contained in the supplied raw material. Furthermore, the shapes and sizes of the first distillation column and the second distillation column are not limited to those shown in the examples, and can be set to any desired shape and size as necessary. Furthermore, although the case where the two distillation columns, the first distillation column 1 and the second distillation column 2, are used for concentration has been described, the present invention is not limited to the case where only the first distillation column is used. It may be a case where the above distillation column is additionally used.

[0041]

As described above, according to the present invention, the ¹⁷ O component is recovered from the bottom of the column where the fluctuation of the concentration ratio is small, and the concentration ratio of the ¹⁷ O component and the ¹⁸ O component is reduced at the bottom of the column. Is equal to the composition ratio of these contained in the raw material,
Since only the amount corresponding to the ¹⁷ O component and ¹⁸ O component contained in the supplied raw material is recovered, the ¹⁷ O component and ¹⁸ O component at the bottom of the column are recovered.
Concentration ratio of O component contained in the raw material is maintained equal to the component ratio of the composite can be easily concentrated to high concentrations of very small ¹⁷ O in natural abundance, further, in this way ¹⁷ O component is concentrated If the side stream fraction is recovered by performing secondary distillation using the obtained product as a raw material, the ¹⁷ O component concentrated to a higher concentration can be recovered stably and the production cost can be greatly reduced. It has a very excellent effect.

[Brief description of drawings]

FIG. 1 is a flow sheet showing an oxygen isotope enrichment device used in the present invention.

[Explanation of symbols]

1 --- First distillation column 2 --- Second distillation column 3 --- Raw material supply pipe 4--To top distillation Fractional discharge pipe 5 ... Tower bottom fraction discharge pipe 6 ... Side flow fraction discharge pipe 7 ... N ¹⁶ O storage tank 8 ...・ ・ ・ ・ ・ ・ Drain 9 ・ ・ ・ ・ ・ ・ Intermediate product storage tank 10 ・ ・ ・ ・ ・ ・ Gas detector 11 ・ ・ ・ ・ ・ ・ Control device 12 ・ ・ ・ ・ ・ ・・ ・ Supply pipe 13 ・ ・ ・ ・ ・ ・ ・ ・ Top column fraction discharge pipe 14 ・ ・ ・ ・ ・ ・ Column bottom fraction discharge pipe 15 ・ ・ ・ ・ ・ ・ Side flow fraction discharge pipe 16・ ・ ・ ・ ・ ・ ・ ・ N ¹⁷ O storage tank 17 ・ ・ ・ ・ ・ ・ N ¹⁸ O storage tank 18a, 18b ・ ・ ・ Gas detector 19 ・ ・ ・ ・ ・ ・ Control device V ₃ , _{V 4, V 5, V 12} , V 13, V 14, V 15 ··· valve Q _{3 Q 4, Q 5, Q 12} , Q 13, Q 14, Q 15 ··· flow detector

Claims (2)

[Claims] 1. Oxygen isotope¹⁶O,¹⁷O and¹⁸Acid containing O
The raw materials are oxygen or oxygen compounds, and each isotope is supplied to the distillation column.
A method for concentrating oxygen isotopes for concentrating a body, comprising: a) a distillation operation for distilling a raw material packed in a distillation column;
The top fraction and bottom fraction are withdrawn while feeding
And the total amount of material extracted should be equal to the amount of raw material supplied.
B) withdrawing operation is performed alternately,
Intake ratio is included in raw materials¹⁶Less than composition ratio of O component
And the ratio of the amount of the bottom fraction extracted is included in the raw material.
Be¹⁸Set it higher than the composition ratio of the O component and keep it at the bottom of the tower.
Ru¹⁷With O component ¹⁸Those in which the concentration ratio of O component is included in the raw materials
Repeat each of the above operations until the concentration ratio of¹⁷O component and¹⁸The concentration ratio of the O component at the bottom is the concentration of the raw material
After the ratio becomes almost equal, while supplying the raw materials¹⁷O component
as well as¹⁸The bottom fraction in which the O component is concentrated is used as the raw material supply amount.
Column bottoms collection operation to collect only a large amount and do not supply raw materials.
Rattle¹⁶The overhead fraction enriched with O component is equal to the raw material supply amount.
Alternately repeat withdrawal operation of top fraction
Along with performing the recovery operation and the extraction operation, distillation
A distillation operation for distilling the raw material packed in the column is performed, and d)¹⁷O component and¹⁸Concentration ratio of the bottom of O component
In order to maintain the ratio equal to
Included in the raw materials supplied¹⁶The amount of O component during the sampling operation
Contained in the raw materials supplied to¹⁷With O component¹⁸Total of O component
That the raw material supply amount is set to be slightly higher than the amount
A characteristic method for enriching oxygen isotopes. 2. Oxygen isotope¹⁶O,¹⁷O and¹⁸Acid containing O
The raw materials are oxygen or oxygen compounds, and each isotope is supplied to the distillation column.
In the method of enriching oxygen isotopes for enriching the body,
After supplying to one distillation column and performing the primary distillation,
The bottom fraction obtained by the secondary distillation is fed to the second distillation column.
A) a distillation operation for performing secondary distillation, A) in the primary distillation, a) distilling the raw material packed in the first distillation column
While supplying the raw materials, the top fraction and bottom fraction are
Make sure that the sampling rate and the total sampling rate are equal to the raw material supply rate
Alternately with the withdrawing operation, b) Withdrawing the overhead fraction with respect to the total withdrawal amount for one operation of the withdrawing operation.
Intake ratio is included in raw materials¹⁶Less than composition ratio of O component
And the ratio of the amount of the bottom fraction extracted is included in the raw material.
Be¹⁸Set it higher than the composition ratio of the O component and keep it at the bottom of the tower.
Ru¹⁷With O component ¹⁸Those in which the concentration ratio of O component is included in the raw materials
Repeat each of the above operations until the concentration ratio of¹⁷O component and¹⁸The concentration ratio of the O component at the bottom is the concentration of the raw material
After the ratio becomes almost equal, while supplying the raw materials¹⁷O component
as well as¹⁸The bottom fraction in which the O component is concentrated is used as the raw material supply amount.
Column bottoms collection operation to collect only a large amount and do not supply raw materials.
Rattle¹⁶The overhead fraction enriched with O component is equal to the raw material supply amount.
Alternately repeat withdrawal operation of top fraction
Along with performing the recovery operation and the extraction operation, distillation
A distillation operation for distilling the raw material packed in the column is performed, and d)¹⁷O component and¹⁸Concentration ratio of the bottom of O component
In order to maintain the ratio equal to
Included in the raw materials supplied¹⁶The amount of O component during the sampling operation
Contained in the raw materials supplied to¹⁷With O component¹⁸Total of O component
The raw material supply amount is set to be slightly larger than the amount, B) in the second distillation, e) the bottom fraction obtained by the first distillation is used as a raw material
Distillation operation to fill the second distillation column and distill, and the overhead fraction
And withdrawal operation for withdrawing the bottom fraction by a predetermined amount alternately
At the side distillate discharge position of the second distillation column¹⁷O success
Min) to the target value, f) at the side distillate discharge position of the second distillation column¹⁷O component
After the concentration reaches the target value, while supplying the raw materials¹⁷O success
The side-stream distillate enriched in
While collecting and supplying raw materials¹⁶O component is concentrated
The overhead fraction and¹⁸The bottom fraction of the O component is collected
At a fixed rate, and the total withdrawal amount becomes equal to the raw material supply amount
Repeat the above withdrawing operation alternately and
Fill the second distillation column between the recovery operation and the extraction operation.
Characterized by performing a distillation operation to distill the raw materials
Method for enriching oxygen isotopes.