RU2692188C1 - Method of producing highly enriched xenon concentrate (versions) - Google Patents

Abstract

FIELD: technological processes.SUBSTANCE: invention relates to gas separation. Method includes at least two cycles of steps, each of which involves adsorption and separate desorption. Desorption involves desorption of xenon and first accompanying gases, each of which has desorption activation energy lower than that of xenon, and then desorption of second accompanying gases, each of which has desorption activation energy higher than that of xenon. During the first desorption the adsorber is evacuated at pressure and temperature, which provide xenon desorption, and a gas mixture is obtained, which is accumulated in a closed volume. During the second desorption, the adsorber is evacuated at lower pressure and at a temperature which ensures desorption of the associated gas, having the highest desorption activation energy from the second accompanying gases. At the last cycle of steps, the gas mixture accumulated in the closed volume is used as the initial cycle, and during the first desorption the highly enriched xenon concentrate is obtained.EFFECT: invention enables to use mixtures with low content of xenon, improves quality and reduces prime cost of the end product.19 cl, 2 dwg

Description

The present invention relates to the separation of components of gas mixtures, and more specifically to a method for producing highly enriched xenon concentrate (versions).

Unique physical properties make xenon indispensable for many branches of human activity, including in the space industry, electronics and medicine.

Currently, the main consumers of xenon are enterprises of the lighting, electronic, aerospace, laser industry, as well as basic physical research and medicine.

Xenon is an ideal working body of ionic rocket engines, is indispensable in the manufacture of integrated circuits of a new generation with three-dimensional architecture, has a powerful, easily controlled narcotic effect, many therapeutic properties, and is comfortable to use.

Xenon is considered an anesthetic of the XXI century. Included in the state register of medicines of Russia and another twelve countries of Europe.

At present, the cost of xenon is high, since the only source of it is atmospheric air, the xenon content of which is 8.7 × 10 ^-6 % by volume.

The raw material for obtaining pure xenon is a krypton-xenon mixture (Kr 93% by volume, Xe 7% by volume) obtained at the air separation plants of metallurgical plants as an additional product of oxygen production used in steelmaking. Moreover, the raw material base for obtaining the specified krypton-xenon mixture is strictly limited to the metallurgical industry. In the production of one million tons of steel, only about 25 nm ^{3 of} xenon can be obtained.

Currently, some applications of xenon are under pressure of high prices, which hinders the development of relevant industries. This forms the accumulated pent-up demand, the volume of which many times exceeds today's capabilities of humanity for its production. For ten years from 2007 to 2017, mankind has produced annually about 10,000 nm ^{3 of} xenon per year.

The expert community is unanimous that the beginning of large-scale use of xenon in new technologies is hampered by the lack of technological capabilities to consistently meet this demand.

A method of obtaining purified gaseous oxygen from the air at air separation plants (RU No. 2174041), in which a krypton-xenon concentrate is obtained as an additional (by-product) product. This method involves dividing air into streams, supplying the main stream of liquid oxygen from the upper column to the group of series-connected main condensers, evaporating part of the stream of liquid oxygen in the group of condensers, withdrawing part of the stream of liquid oxygen from the group of main condensers in the form of a circulation stream of liquid oxygen, partial evaporation in the evaporator-condenser flow with the formation of two streams - a stream of purified gaseous oxygen (as the target product) and a stream of liquid oxygen yes enriched xenon and krypton (by-product), whereupon the flow of liquid oxygen produced a gas mixture containing kriptonoksenonovy concentrate.

This method involves the use of atmospheric air as the source gas mixture to obtain a specified amount of purified gaseous oxygen, obtained as the target product. At the same time, as an additional product, when implementing this method, a krypton-xenon concentrate is obtained, the amount of which is limited by the amount of oxygen gas obtained.

The use of this method directly to obtain xenon concentrate from hydrocarbon gas mixtures as the main target product is impossible, since this method implements temperature and pressure conditions and process conditions that ensure the separation of nitrogen and oxygen, which eliminates the production of xenon concentrate from hydrocarbon gas mixtures as the main target product.

A method of obtaining highly enriched xenon concentrate (RU 2259522), taken as a prototype. This method contains three different technological process. The first technological process consists in sequentially performing a cycle of steps, including: directing the initial gas mixture containing xenon and accompanying gases to adsorption to an adsorber pre-filled with an adsorbent; gases with constant heat removal to produce a gas mixture, which before the xenon gas appears in the gas mixture is removed from the process, and after it appears in it enone adsorption stopped, and the regeneration of the adsorbent is performed by performing simultaneous xenon desorption and all available accompanying gases that are a constant supply of heat at a temperature of 333 to 353 ° K and continuing substantially until no more xenon desorbed from the adsorbent in the gas mixture. The desorbed gas mixture obtained as a result of simultaneous desorption contains xenon and accompanying gases that were present in the original gas mixture and were desorbed simultaneously with xenon.

At the same time, the simultaneous desorption of xenon and associated gases during the implementation of the first technological process eliminates the qualitative removal of accompanying gases from the original gas mixture and requires two more different technological processes to obtain highly enriched xenon concentrate.

For the subsequent removal of the remaining accompanying gases from the resulting desorbed gas mixture, a second process is carried out - catalytic burning, in which the desorbed gas mixture is directed to catalytic burning of hydrocarbons at a temperature of 900-950 K. with a constant supply of heat at a temperature of from 720 to 1050 K, as a result of which there is a catalytic burning out of fluorine-chloroderivat levodorodov.

After this, a third process is carried out, in which the resulting gas mixture is cooled to a temperature of 290-300 K and sent for adsorption purification from water vapor and carbon dioxide.

As a result of three different technological processes, a gas mixture containing highly enriched xenon concentrate (xenon content from 30 to 85 vol%) is obtained.

Simultaneous desorption of xenon and all associated gases using the temperature regimes described above leads to simultaneous removal of xenon and all associated gases from the initial gas mixture into the desorbed gas mixture, which reduces the xenon concentration in highly enriched xenon concentrate, and therefore reduces the quality of the latter.

In addition, the implementation of these three technological processes requires the use of a large number of various complex equipment and high energy costs, which leads to high capital and energy costs, which leads to an increase in the cost of the target product.

In this method, only an expensive gas mixture with a high xenon content (for example, from 10 to 28% by volume (further vol.%)) Obtained as an additional product from a previous multi-stage process (for example, can be used as the source gas mixture , air separation at air separation plants of metallurgical plants), which limits the amount of highly enriched xenon concentrate produced to the required amount of target of the previous process. In this method, the possibility of using a gas mixture with a low (for example, 10 ^-2 to 10 ^-1 % by volume) and a particularly low (for example, 10 ^-2 % or less) xenon content in as the initial gas mixture, as in the implementation of simultaneous desorption there is an increase in the content in the desorbed gas mixture of the first and second associated gases (i.e. an increase in the concentration of hydrocarbons in the desorbed gas mixture); izhaet quality highly xenon concentrate. This narrows the range of source gas mixtures, and also eliminates the possibility of its production as the main target commercial product on an industrial scale without limiting the amount of its production by previous and subsequent technological processes, which excludes the possibility of increasing its production.

Moreover, the use of this additional product as an initial gas mixture ensures the presence of free oxygen in the amount of more than 10 vol. %, that is, as an accompanying gas. This eliminates the possibility of using the most effective adsorbents with the highest sorption capacity for xenon, for example, activated carbon. This is due to the fact that when interacting with oxygen in an amount of 10 vol. % and more activated carbon can create explosive conditions.

The basis of the present invention is to create a method that will provide the possibility of obtaining highly enriched xenon concentrate as the main target commercial product on an industrial scale without limiting the amount of its production by previous and subsequent technological processes, improve the quality of highly enriched xenon concentrate expand the range of source gas mixtures by providing the possibility of using g zovyh mixtures of low and very low content of xenon, which will reduce the cost of the title product.

This problem is solved by creating a method of obtaining highly enriched xenon concentrate, containing the execution of a cycle of steps, including the direction of the original gas mixture containing xenon and associated gases, to the adsorber pre-filled with the adsorbent, continuous measurement at the outlet from the adsorber of the composition of the gas passing through the adsorber, xenon adsorption and associated gases to produce a gas mixture, which, before the appearance of xenon in it, is removed from the process, and after the appearance of xenon in it, o it is stopped and the adsorbent is regenerated by performing desorption of xenon and associated gases, wherein, according to the invention, at least two cycles of these steps are carried out sequentially, with each of which performing separate desorption, including the first desorption, at which desorption of xenon and the first associated gases, each of which has an activation energy of desorption is less than that of xenon, and which is carried out by evacuating the adsorber at pressure and temperature, ensuring desorption of xenon, and the second desorption, in which the desorption of the second accompanying gases, each of which has an activation energy for desorption, is greater than that of xenon, and which is carried out by evacuating the adsorber at a pressure below the evacuation pressure of the adsorber at the first desorption and at a temperature that provides desorption of accompanying gas having the highest activation energy of desorption from the second associated gases, moreover, during the first desorption at least the first cycle of steps form desorption This gas mixture containing xenon and the first accompanying gases, which are sent to a closed volume, where they accumulate essentially until the release of xenon from the adsorbent stops, and during the second desorption of each cycle of steps they form a desorbed gas mixture containing the second accompanying gases, which are removed from the process, at the same time, at least in the last cycle of steps, the desorbed gas mixture accumulated in a closed volume of at least the first cycle of steps is used as the source gas mixture, and during the first dec the last cycle of steps rbtsii desorbed gas mixture is obtained, which is a highly-xenon concentrate.

The technical result of the invention is to provide new functionality of the method, namely the possibility of obtaining highly enriched xenon concentrate as the main target commercial product on an industrial scale without limiting the amount of its production by previous and subsequent technological processes, to improve the quality of highly enriched xenon concentrate by increasing its concentration xenon, in expanding the range of source gas mixtures by both baking the possibility of using gas mixtures with low and high-low xenon, which reduces the cost of the desired product.

This is due to the fact that the implementation of separate desorption improves desorption of xenon from the adsorbent, makes it possible to use as the source gas mixture when performing the corresponding subsequent cycles of steps a gas mixture enriched with xenon, obtained when performing the previous cycles of steps, which increases the xenon content in the desorbed gas mixture of the last cycle steps and improves the quality of highly enriched xenon concentrate. In addition, the implementation of separate desorption during the execution of each cycle of steps ensures almost complete removal of the second accompanying gases from the initial gas mixture, since these gases are removed from the process during the execution of each cycle, and the sequential execution of at least two cycles of steps reduces the amount in the target product first accompanying gases, as these gases, when performing adsorption of each cycle of steps, are only partially absorbed by the adsorbent, and partly these gases are removed from the adsorber with passing gas mixture when performing each cycle of steps. All this reduces the amount of first and second accompanying gases in the target product and increases the xenon content, which improves the quality of highly enriched xenon concentrate, and also eliminates the need for additional technological processes, which reduces the cost of the target product. At the same time, sequential execution of at least two cycles of steps allows expanding the range of source gas mixtures by ensuring that gas mixtures with low and especially low xenon contents can be used without limiting the amount of high-enriched xenon concentrate production by previous and subsequent processes, which allows essentially unlimited expansion of xenon production as the main target product.

It is advisable that prior to supplying the initial gas mixture to the adsorber, in the first cycle of steps, the initial gas mixture is pre-cleaned from drip liquids and mechanical impurities, and at each cycle of steps the pressure of the original gas mixture of the corresponding cycle of steps is stabilized from 6 to 10 bar and its temperature from 268 up to 293 K. This protects the adsorbent from damage and clogging, prolongs its life before replacement. It also increases the amount of non-adsorbed first associated gases passing through the adsorber and reduces their amount during the first desorption.

It is desirable that at the initial stage of the first desorption of the first cycle of steps, the first part of the desorbed gas mixture containing xenon in smaller quantities than in the initial gas mixture of the first cycle of steps, which was removed from the process, was formed, and the second part of the desorbed gas mixture, which formed as a result of the continuation of the first desorption of the first cycle of steps after the specified elimination. The author of the present invention has experimentally established that at the initial stage of the first desorption, before the start of desorption of xenon, the first associated gases are sequentially desorbed. Therefore, first form the first part of the desorbed gas mixture containing an increased concentration of the first accompanying gases and a reduced concentration of xenon, and then form the second part of the desorbed gas mixture enriched in xenon and having a reduced content of the first accompanying gases. This reduces the amount of first associated gases and increases the xenon content in the target product, which improves the quality of highly enriched xenon concentrate.

It is favorable that at the initial stage of the first desorption of the last cycle of steps, the first part of the desorbed gas mixture containing xenon in smaller quantities than in the initial gas mixture of the last cycle of steps, which was removed from the process, was formed, and highly enriched xenon concentrate was obtained in the second part of the desorbed gas mixture, which was formed as a result of the continuation of the first desorption of the last cycle of steps after the specified elimination. As described above, the author of the present invention has established experimentally that at the initial stage of the first desorption, before the start of desorption of xenon, the first associated gases are sequentially desorbed. Therefore, first form the first part of the desorbed gas mixture containing an increased concentration of the first accompanying gases and a reduced concentration of xenon, and then form the second part of the desorbed gas mixture, which is a highly enriched xenon concentrate containing the residual concentration of the first associated gases. This reduces the amount of first associated gases and increases the xenon content in the target product, which improves the quality of highly enriched xenon concentrate.

It is useful that the first part of the desorbed gas mixture, derived at the initial stage of the first desorption of the last cycle of steps, is partially returned to the original gas mixture of the first cycle of steps. This increases the xenon extraction rate (up to 40%).

It is possible that as the initial gas mixture of the first cycle of steps, a natural hydrocarbon gas mixture was used, in which there was no free oxygen in the accompanying gases, while activated carbon was used as the adsorbent during each step cycle. This increases the content of xenon in the desorbed gas mixture, which improves the quality of highly enriched xenon concentrate, and also provides the possibility of obtaining highly enriched xenon concentrate as the main product in unlimited quantities.

Conveniently, as a natural hydrocarbon gas mixture, a gas mixture is used, which contains at least methane and carbon dioxide as the first accompanying gases, and contains at least ethane, propane, butane as the second accompanying gases. Such a gas mixture is widely distributed in nature and its use makes it possible to obtain highly enriched xenon concentrate as the main target commercial product on an industrial scale without limiting the amount of its production by previous and subsequent technological processes, which allows expanding the range of initial gas mixtures to obtain highly enriched xenon concentrate and to reduce the cost of the target product while improving the quality of highly enriched xenon th concentrate.

Preferably, when performing each cycle of steps, the first desorption is carried out by evacuating the adsorber at a constant pressure of 30 to 100 mbar and a constant temperature of 268 to 293 K, and the second desorption is carried out by evacuating the adsorber at a constant pressure of 2 to 30 mbar and a constant temperature 373 to 423 K. It is experimentally established by the author of the present invention that with the indicated characteristics of the first desorption process, first desorption of the first associated gases begins to occur, and then Xenon desorption occurs, resulting in the separation of the first accompanying gases and xenon from the second associated gases, which increases the xenon content in the desorbed gas mixture, which is accumulated in a confined space, which, in turn, improves the quality of the highly enriched xenon concentrate obtained during the last cycle . In addition, the author experimentally established that, with the indicated characteristics of the second desorption process, desorption of ethane, propane, butane and essentially complete regeneration of the adsorbent occurs, which improves the subsequent adsorption and desorption of xenon and improves the quality of highly enriched xenon concentrate. When this occurs, the formation of the desorbed gas mixture containing the second associated gases: ethane, propane, butane, which is removed from the process, which increases the content of xenon in highly enriched xenon concentrate and improves the quality of the target product.

It is possible that a natural hydrocarbon gas mixture containing xenon in an amount of 10 ^-2 vol. % or less, at the same time at least four cycles of steps were performed, of which at least the second and third cycles of steps were performed similarly to the first cycle of steps, and during each subsequent cycle of steps, the gas mixture accumulated in the corresponding closed gas was used as the initial gas mixture volume when performing the corresponding previous cycle steps. This allows you to expand the range of source gas mixtures by using gas mixtures not only with low, but also especially low xenon content without limiting the amount of high-enriched xenon concentrate obtained by previous technological processes, which reduces the cost of the target product with increasing xenon content in the desorbed gas mixture, which improves the quality highly enriched xenon concentrate.

It is favorable that at the initial stage of the first desorption of each subsequent cycle of steps a first part of the desorbed gas mixture is formed, containing xenon in smaller quantities than in the initial gas mixture of the corresponding cycle of steps that was taken out of the process, and the second part of the desorbed gas mixture was directed into a closed volume, which was formed as a result of the continuation of the first desorption of each subsequent cycle of steps after the specified elimination. It is useful for the initial stage of the first desorption of each subsequent cycle of steps to form the first part of the desorbed gas mixture containing xenon in smaller quantities than in the original gas mixture of the corresponding cycle of steps that was removed from the process, and the highly enriched xenon concentrate was obtained in the second part of the desorbed gas mixture, which was formed as a result of the continuation of the first desorption of the last cycle of steps after the specified elimination. The author of the present invention experimentally found that at the initial stage of the first desorption, before the start of desorption of xenon, the first accompanying gases are sequentially desorbed, therefore, they first form the first part of the desorbed gas mixture, which contains an increased concentration of the first accompanying gases and a reduced xenon concentration, which is removed from the process, and then form the second part of the desorbed gas mixture, which is a highly enriched xenon concentrate containing residual end concentration of the first associated gases. This reduces the amount of first associated gases and increases the xenon content in the target product, which improves the quality of highly enriched xenon concentrate.

Preferably, the first part of the desorbed gas mixture, derived at the initial stage of the first desorption of each subsequent cycle of steps, is partially returned to the original gas mixture of the corresponding previous cycle steps. This increases the xenon extraction ratio.

It is possible that the second part of the desorbed gas mixture obtained during the last cycle of steps, which is a highly enriched xenon concentrate, is directed to fine cleaning of the remaining associated gases and / or impurities and to obtain pure xenon. This allows you to get xenon with a purity of 99.9999.

Thus, the proposed method provides a new functional opportunity to obtain highly enriched xenon concentrate as the main target commercial product on an industrial scale without limiting the amount of its production by previous and subsequent technological processes, provides for improving the quality of highly enriched xenon concentrate by increasing xenon concentration in it, assortment of the original gas mixtures by ensuring use of gas mixtures with low and extremely low xenon content, which reduces the cost of the target product.

The task is also solved by creating a method of obtaining highly enriched xenon concentrate, comprising performing a cycle of steps, including: directing the initial gas mixture containing xenon and associated gases to an adsorber pre-filled with an adsorbent, continuous measurement of the gas mixture passing through the adsorber at the outlet from the adsorber, adsorption of xenon and associated gases to produce a gas mixture, which, before the appearance of xenon in this gas mixture, is removed from the process, and after the xenon adsorption in it is stopped and the adsorbent is regenerated by desorption of xenon and associated gases, wherein, according to the invention, at least four cycles of the above steps are carried out sequentially, the first of which use a natural hydrocarbon gas mixture as an initial gas mixture which contains xenon in an amount of 10 ^-2 vol. % and less and in which there is no free oxygen in accompanying gases, while at each cycle of steps activated carbon is used as an adsorbent and separate desorption is carried out, including the first desorption, at which desorption of xenon and first associated gases is performed, each of which has an activation energy desorption is less than xenon, and which is carried out by evacuating the adsorber at pressure and temperature, providing desorption of xenon, and a second desorption, at which desorption is performed second accompanying gases, each of which has an activation energy for desorption is greater than xenon, and which is carried out by evacuating the adsorber at a pressure lower than the evacuation pressure of the adsorber during the first desorption and at a temperature ensuring desorption of the accompanying gas having the highest desorption activation energy from the second accompanying gases, while at the initial stage of the first desorption of each cycle of steps form the first part of the desorbed gas mixture containing xenon in smaller quantities than in the initial gas mixture of the corresponding cycle of steps, which is removed from the process, and as a result of continuing the first desorption after this elimination, a second part of the desorbed gas mixture is formed, which in each of the first three cycles of the steps is directed to the corresponding closed volume, where they accumulate xenon from the adsorbent, and during the second desorption of each cycle of steps they form a desorbed gas mixture containing the second accompanying gases, which is removed from the process, and for each After the subsequent cycle of steps, the corresponding second part of the desorbed gas mixture accumulated in the corresponding closed volume of the corresponding previous cycle of steps is used as the initial gas mixture, and the second cycle of steps resulting from the continuation of the first desorption after the elimination gives the second part of the desorbed gas mixture, which is highly enriched. xenon concentrate.

The technical result of the proposed method is to provide a new functional possibility of obtaining highly enriched xenon concentrate as the main target commercial product on an industrial scale without limiting the amount of its production by previous and subsequent technological processes, to improve the quality of highly enriched xenon concentrate by increasing its xenon concentration, as well as expanding the range of source gas mixtures by ensuring the use of Use of gas mixtures with low and extremely low xenon content, which ensures a reduction in the cost of the target product.

This is due to the fact that the implementation of separate desorption improves the desorption of xenon from the adsorbent, makes it possible to use the xenon-enriched gas mixture in the previous cycle of steps as the initial gas mixture, which increases the xenon content in the desorbed gas mixture of each subsequent cycle steps, resulting in increased xenon content in highly enriched xenon concentrate, which provides improved quality Lednev. In addition, the implementation of separate desorption when performing each cycle of steps provides almost complete removal of the second accompanying gases from the initial gas mixture, since these gases are removed from the process during the execution of each cycle of steps. In this case, sequentially performing at least four cycles of steps and performing separate desorption during each cycle of steps reduces in the target product the number of first accompanying gases as a result of successive removal of these gases from the adsorber, first with the passing gas mixture during the adsorption of each cycle of steps, and then with the first part of the desorbed gas mixture at the initial stage of desorption of each cycle of steps. All this reduces the amount of first and second accompanying gases in the target product and increases the xenon content, which improves the quality of highly enriched xenon concentrate, and also eliminates the need for additional technological processes, which reduces the cost of the target product. At the same time, sequential execution of at least four cycles of steps allows expanding the range of source gas mixtures by ensuring that gas mixtures with low and especially low xenon contents can be used without limiting the amount of production of highly enriched xenon concentrate by previous and subsequent technological processes, which allows essentially unlimited expansion of xenon production as the main target product.

It is advisable that prior to supplying the initial gas mixture to the adsorber, in the first cycle of steps, the initial gas mixture is pre-cleaned from drip liquids and mechanical impurities, and at each cycle of steps the pressure of the initial gas mixture of the corresponding cycle of steps from 6 to 10 bar and its temperature from 268 up to 293 K. This protects the adsorbent from damage and clogging, which prolongs its life before replacement, which, in turn, reduces the cost of the target product. It also increases the amount of non-adsorbed first associated gases passing through the adsorber and reduces their amount during the first desorption.

It is desirable that the first part of the desorbed gas mixture, derived at the initial stage of the first desorption of each subsequent cycle of steps, be partially returned to the original gas mixture of the corresponding previous cycle steps. This increases the xenon extraction ratio.

Favorably, as a natural hydrocarbon gas mixture used a gas mixture, which as the first accompanying gases contains at least methane and carbon dioxide, and as the second accompanying gases contains at least ethane, propane, butane. Such a gas mixture is common in nature and its use makes it possible to obtain highly enriched xenon concentrate as the main target commercial product on an industrial scale without limiting the amount of its production by previous and subsequent technological processes, which allows expanding the range of initial gas mixtures to obtain highly enriched xenon concentrate and ensure reducing the cost of the target product while maintaining a high xenon extraction ratio.

Preferably, when performing each cycle of steps, the first desorption is carried out by evacuating the adsorber at a constant pressure of 30 to 100 mbar and a constant temperature of 268 to 293 K, and the second desorption is carried out by evacuating the adsorber at a constant pressure of 2 to 30 mbar and a constant temperature 373 to 423 K. As described above, the author of the present invention has established experimentally that, with the indicated characteristics of the first desorption process, first desorption of the first associated gases occurs, and then xenon, resulting in the separation of the first accompanying gases and xenon from the second accompanying gases, which increases the concentration of xenon in the desorbed gas mixture, which is accumulated in a confined space, which provides an increase in the xenon content in the desorbed gas mixture, which, in turn, increases the quality of the highly enriched xenon concentrate obtained in the last cycle of steps. In addition, it has been established experimentally that with the indicated characteristics of the second desorption process, desorption of ethane, propane, butane and essentially complete regeneration of the adsorbent occurs, which improves subsequent adsorption and desorption of xenon and improves the quality of highly enriched xenon concentrate. When this occurs, the formation of a desorbed gas mixture containing the second accompanying gases: ethane, propane, butane, which is removed from the process, which increases the concentration of xenon in highly enriched xenon concentrate and improves the quality of the target product.

It is useful that the second part of the desorbed gas mixture obtained in the last cycle of steps, which is a highly enriched xenon concentrate, is directed to fine cleaning of the remaining accompanying gases and / or impurities and obtaining pure xenon. This allows you to get xenon with a purity of 99.9999.

Thus, the proposed method provides a new functional possibility of obtaining highly enriched xenon concentrate as the main target commercial product on an industrial scale without limiting the amount of its production by previous and subsequent technological processes, provides for improving the quality of highly enriched xenon concentrate by increasing xenon assortment of the original gas mixtures by ensuring the possibility of using zovaniya gas mixtures of low and very low content of xenon, which reduces the cost of the desired product.

The proposed method of obtaining highly enriched xenon concentrate (the first option) is as follows.

The proposed method includes the sequential execution of at least two cycles of steps, each of which includes: directing the initial gas mixture containing xenon and associated gases to the adsorber pre-filled with the adsorbent, continuous measurement of the gas mixture passing through the adsorber at the outlet from the adsorber, adsorption xenon and associated gases to produce an unadsorbed gas mixture, which, before the appearance of xenon in it, is removed from the process, and after the appearance of xenon, adsorption raschayut and perform the regeneration of the adsorbent by desorption separate xenon and accompanying gases.

By the phrase "at least two cycles of steps," we understand that this cycle of these steps is sequentially repeated at least two times. The number of cycles of steps depends on the amount of xenon in the initial gas mixture of the first cycle of steps. The proposed method allows the use of the original gas mixture with a high content of xenon (for example, from 10 to 28 vol.%), With a low content of xenon (for example, from 10 ^-2 to 10 ^-1 vol.%) And a particularly low content of xenon (10 ^{- 2} % by volume and less). The smaller the amount of xenon in the initial gas mixture of the first cycle of steps, the more cycles must be performed. The first and subsequent cycles of steps (if any, before the last cycle of steps) are carried out sequentially and essentially the same. The difference between the first and subsequent cycles of steps lies in the amount of xenon and associated gases in the initial gas mixture of each cycle of steps.

At each cycle of steps, separate desorption of the initial gas mixture is carried out. In this case, the first desorption is first carried out, at which desorption of xenon and first associated gases is performed, each of which has an activation energy of desorption less than xenon, and which is carried out by evacuating the adsorber under pressure and temperature, ensuring desorption of xenon. A second desorption is then carried out, in which the desorption of the second accompanying gases is carried out, each of which has an activation energy of desorption greater than that of xenon, and which is carried out by evacuating the adsorber at a pressure below the evacuation pressure of the adsorber at the first desorption and at a temperature that desorbs the associated gas having the highest activation energy of desorption from the second associated gases. Moreover, during the first desorption of at least the first cycle of steps, a desorbed gas mixture containing xenon and the first accompanying gases is obtained, which is sent to the corresponding closed volume, where they accumulate essentially until xenon is released from the adsorbent, and during the second desorption of each cycle of steps, the desorbed gas is obtained the mixture containing the second associated gases, which is removed from the process. In the last cycle of steps, the desorbed gas mixture accumulated in the closed volume of the previous cycle of steps is used as the initial gas mixture, and during the first desorption of the last cycle of steps, a desorbed gas mixture containing highly enriched xenon concentrate is obtained.

As the initial gas mixture of the first cycle of steps, any gas mixture containing xenon, the first accompanying gases, each of which has an activation energy for desorption less than xenon, and the second associated gases, each of which has an activation energy for desorption, is higher than xenon, can be used. By the phrase "associated gases" we mean gases contained in the source gas mixture in an amount of more than 1%, and by the term "impurities" we mean gases contained in the source gas mixture in an amount less than 1%.

The use of separate desorption of the original gas mixture is based on the theory of desorption kinetics, which is described in the book "Fundamentals of the adsorption technology", Keltsev NV, Moscow, Chemistry Publishing House, 1984 (pp. 152-157).

According to this theory, on p. 155 it is indicated:

where Ed is the activation energy of desorption; Q is the heat of adsorption; EA is the activation energy of adsorption.

Further on page 155 it is indicated:

where c is the proportionality coefficient.

From (1) and (2) follows:

that is, the activation energy of desorption is proportional to the heat of adsorption, which is numerically equal to the work of adsorption.

The same source on p. 69 shows a table 2.9 of the similarity of adsorption of normal saturated hydrocarbons by microporous sorbents, from which it follows that the activation energy of desorption increases as the molecular weight of members of a number of normal saturated hydrocarbons increases.

The same source on p. 157 shows a table 7.1 of the temperature of combining kinetic curves for normal hydrocarbons, from which it follows that desorption of two hydrocarbons of the homologous series at the same pressure describes a single kinetic curve, but with a shift in temperature. The greater the molecular weight of the members of a number of normal saturated hydrocarbons, the greater the temperature of their desorption. Thus, at the same pressure, the desorption of each subsequent normal hydrocarbon occurs at a higher temperature than the previous one.

Based on the theory described above, the author of the present invention has experimentally established that it is also possible to carry out the sequential desorption of normal hydrocarbons from microporous adsorbents at a constant temperature by varying the pressure (vacuum depth).

As an initial gas mixture of the first cycle of steps, a natural hydrocarbon gas mixture with low or very low xenon content can be used. For example, the initial gas mixture of the first cycle of steps may contain xenon in an amount of 10 ^-1 vol. % or more or in the amount of 5 × 10 ^-4 vol. % or less.

The amount of xenon in the initial gas mixture of the first cycle of steps determines the required number of subsequent cycles of steps. The smaller the amount of xenon in the initial gas mixture of the first cycle of steps, the greater the number of subsequent cycles of steps, similar to the first cycle of steps, must be consistently performed.

A natural hydrocarbon gas mixture is taken, for example, from a formed gas mixture stream at an equipped natural field and, if necessary, before the initial gas mixture is fed to the adsorber, in the first cycle of steps, the initial gas mixture is cleaned from drip liquids and mechanical impurities. These operations are carried out by any known method, for example, by using a coalescer filter and a mechanical cleaning filter. This protects the adsorbent from damage and clogging, which prolongs its life before replacement. If necessary, before feeding the source gas mixture to the adsorber, at each cycle of steps, stabilize the pressure of the source gas mixture from 6 to 10 bar and its temperature from 268 to 293 K. This increases the amount of non-adsorbed first associated gases passing through the adsorber and reduces their number during the first desorption.

As a natural hydrocarbon gas mixture, a gas mixture can be used, in which there is no free oxygen in accompanying gases, this makes it possible to use activated carbon as the adsorbent, which has the highest sorption capacity relative to xenon among the known adsorbents. The absence of free oxygen in accompanying gases eliminates the possibility of an explosive situation arising, the risk of which occurs when activated carbon interacts with free oxygen present in large quantities in accompanying gases (10% or more). That is, in the initial gas mixture, free oxygen may be present, for example, as an impurity (less than 1 vol.%), But its amount should not exceed 10 vol. %, which can create an explosive situation.

The use of activated carbon helps to increase the concentration of xenon in the accumulated desorbed gas mixture, which improves the quality of highly enriched xenon concentrate.

When using a gas mixture in which free oxygen is present in accompanying gases, for example, silica gel or zeolites can be used as an adsorbent, the use of which eliminates the risk of fire or explosion.

It is most effective to use a gas mixture as a natural hydrocarbon gas mixture, which contains at least methane and carbon dioxide as the first accompanying gases, and contains at least ethane, propane, butane as the second accompanying gases. This gas mixture is widespread and makes it possible to obtain highly enriched xenon concentrate as the main target commercial product on an industrial scale without limiting the amount of its production by previous and subsequent technological processes, which allows you to expand the range of source gas mixtures.

The initial gas mixture as the first accompanying gases may additionally contain, for example, nitrogen, while in these associated gases the presence of various impurities is possible (for example, krypton, helium), the content of each of which is less than 1 vol. %

When adsorbing xenon and associated gases to the adsorbent surface, xenon, the first accompanying gases and the second accompanying gases are adsorbed, and a non-adsorbed gas mixture containing poorly adsorbed (eg, methane) or not adsorbed (eg, nitrogen) is formed in the adsorber volume in the intergranular space of the adsorbent. a) components of the first associated gases. The non-adsorbed gas mixture passes through the adsorber and is withdrawn from the process (this mixture is called the gas mixture passing through the adsorber). This ensures the partial removal of the first accompanying gases from the initial gas mixture during the execution of each cycle of steps, which increases the concentration of xenon in the desorbed gas mixture of each cycle of steps. With constant measurement of the composition of the gas mixture leaving the adsorber, at the outlet from the adsorber, determine the time at which xenon appears in the non-adsorbed gas mixture, which is removed from the process. After the appearance of xenon, adsorption is stopped and the adsorbent is regenerated by performing separate desorption of xenon and associated gases.

When performing at least the first cycle of steps, the first desorption is carried out by evacuating the adsorber at a constant pressure of from 30 to 100 mbar, and a constant temperature of from 268 to 293 K, providing desorption of xenon. It has been established experimentally that before desorption of xenon, desorption of the first associated gases begins to occur, since each of them has an activation energy of desorption less than that of xenon, after which desorption of xenon gradually begins to occur. Moreover, desorption of xenon starts earlier than the desorption of the first associated gases ends, in accordance with their activation energies of the desorption process. When this occurs, the separation of xenon and the first associated gases from the second associated gases, which remain almost entirely in the adsorbent. That is, as a result of the implementation of the first desorption of the first cycle of steps at the outlet of the adsorber, a xenon-enriched desorbed gas mixture is obtained, which has a reduced content of the first accompanying gases removed during adsorption and contains the minimum amount of second associated gases. This mixture is sent to the appropriate closed volume, where they accumulate essentially (almost) until the release of xenon from the adsorbent stops.

If evacuation during the first desorption is carried out at a constant pressure of less than 30 mbar or at a constant temperature of more than 293 K, then simultaneously with the desorption of the first associated gases and xenon, desorption of at least one of the second associated gases, which has the lowest second associated gases, (for example, ethane), which can get into the desorbed gas mixture accumulated in a confined space and reduce the concentration of xenon. If during the first desorption the vacuum is carried out at a constant pressure of more than 100 mbar or at a constant temperature of less than 268K, then the desorption of xenon may not be carried out effectively enough and the xenon will not be completely removed.

As mentioned above, the author of the present invention has established experimentally that the implementation of the first desorption occurs gradually, while at the initial stage of the first desorption, in accordance with the activation energies of desorption (from a smaller value to a larger one), the first associated gases are successively desorbed before the xenon desorption, and then gradually begins to desorb xenon. Moreover, the desorption of xenon begins earlier than the desorption of the first associated gases ends, in accordance with their activation energy of desorption. As a result, at the initial stage of the first desorption of at least the first cycle of steps, the first part of the desorbed gas mixture is formed, containing an increased concentration of the first accompanying gases and a reduced concentration of xenon compared to their concentration in the initial gas mixture of the first cycle of steps. This first part of the stripped gas mixture is removed from the process. After this removal, the first desorption is continued, at which the maximum desorption of xenon occurs, and a second part of the desorbed gas mixture is enriched in xenon, which has a residual concentration of the first accompanying gases. This second part of the desorbed gas mixture is sent to the corresponding closed volume, where it is accumulated essentially until the release of xenon from the adsorbent is stopped. This significantly reduces the concentration of the first accompanying gases and increases the concentration of xenon in the second part of the desorbed gas mixture, which accumulates in the corresponding closed volume, which increases the xenon content in the highly enriched xenon concentrate, obtained in the last cycle of steps, and therefore increases the quality of highly enriched xenon concentrate. Thus, during the first cycle of steps, a desorbed gas mixture is accumulated in a closed volume, which is enriched with xenon in comparison with the initial gas mixture, has a lower content of first accompanying gases and contains a minimum amount of second associated gases.

After the first desorption, when performing each cycle of steps, a second desorption is carried out, namely the desorption of the second associated gases, each of which has an activation energy of desorption greater than that of xenon. The second desorption is carried out by vacuuming the adsorber at a pressure below the vacuum pressure of the adsorber during desorption of xenon (at the first desorption), and at a temperature that desorbs the component of the accompanying gas with the highest activation energy of desorption (in this example it is butane). With the indicated characteristics of the second desorption process, the second associated gases (ethane, propane, butane) are desorbed and the adsorbent is completely regenerated, which improves the further desorption of xenon. The result is the formation of a desorbed gas mixture containing the second associated gases: ethane, propane, butane, which is removed from the process, which increases the concentration of xenon in the accumulated desorbed gas mixture, and therefore improves the quality of highly enriched xenon concentrate.

The second desorption is most efficiently carried out by evacuating the adsorber at a constant pressure of 2 to 30 mbar and a constant temperature of 373 to 423 K. If the evacuation at the second desorption is carried out at a pressure of less than 2 mbar or at a temperature of more than 423 K, this will not improve the desorption of these second related gases, and the energy required for this will be wasted. If vacuuming during the second desorption is carried out at a pressure of more than 30 mbar or at a temperature of less than 373 K, then incomplete desorption of butane from the adsorbent may occur and, therefore, incomplete regeneration of the adsorbent, which may hinder further adsorption of xenon and reduce the quality of highly enriched xenon concentrate.

After the first cycle of steps has been completed, subsequent cycles of steps (if any) are carried out in a similar manner, which are carried out similarly to the described first cycle of steps. After each of the specified cycles of steps in the corresponding closed volume, a desorbed gas mixture enriched with xenon is obtained.

Then, the last cycle of steps is carried out, in which the desorbed gas mixture accumulated in the corresponding closed volume as a result of the corresponding first desorption of the first (previous) cycle of steps is used as the initial gas mixture. This accumulated desorbed gas mixture is again sent to the adsorber, which is filled with activated carbon. Then, similarly to the first cycle of steps, xenon and associated gases are adsorbed to produce an adsorbed gas mixture, which is removed from the process until xenon appears in it, and after xenon appears in it, adsorption is stopped and the adsorbent is regenerated by performing separate desorption. When the last cycle of steps is desorbed separately, the first desorption is first carried out, where desorption of xenon and first associated gases is performed, each of which has an activation energy of desorption less than xenon, and then a second desorption is carried out, at which desorption of the second associated gases is performed, each of which activation energy desorption is greater than xenon.

The first desorption of the last cycle of steps is carried out by evacuating the adsorber at a constant pressure of from 30 to 100 mbar, and a constant temperature of from 268 to 293 K, providing desorption of xenon. In this case, as described above, before desorption of xenon starts desorption of the first associated gases, as each of them has an activation energy of desorption less than xenon, and then gradually begins desorption of xenon. Moreover, the desorption of xenon begins earlier than the desorption of the first associated gases ends, in accordance with their activation energy of desorption. When this occurs, the separation of xenon and the first associated gases from the second associated gases, which remain almost entirely in the adsorbent. That is, as a result of the implementation of the first desorption of the last cycle of steps at the outlet from the adsorber, a desorbed gas mixture is obtained, which is a highly enriched xenon concentrate containing the minimum residual content of the first accompanying gases, and there may be a minimum amount of second associated gases.

The need for a second desorption of the last cycle of steps is due to the fact that the desorption of xenon during the first desorption may end somewhat later than the second desorption components of the second accompanying gases that have the lowest activation energy of desorption from the second associated gases (for example, ethane) begin. As a result, the specified components of the second accompanying gases can get into the closed volume, which will be removed from the process during the second desorption of the last cycle of steps.

The second desorption of the last cycle of steps is carried out similarly to the second desorption of the first cycle of steps described above.

In this case, during the implementation of the first desorption of the last cycle of steps, a desorbed gas mixture is obtained containing highly enriched xenon concentrate containing xenon, for example, from 32 to 38 vol. % and the residual content of the first accompanying gases (for example, the methane content is from 50 to 60 vol.%, the rest of the remaining accompanying gases and impurities).

As described above, it has been experimentally established that the first desorption of the last cycle of steps (similar to that described for the first cycle of steps) occurs gradually, while at the initial stage of the first desorption of the last cycle of steps, in accordance with the activation energies of the desorption process, the remaining first accompanying gases, and then gradually begins to desorb xenon. Therefore, in the initial stage of the first desorption of the last cycle of steps, the first part of the desorbed gas mixture is formed, which has an increased concentration of the first associated gases and a reduced concentration of xenon compared to their concentration in the initial gas mixture of the last cycle of steps. This first part of the stripped gas mixture is removed from the process. After this elimination, continue the first desorption of the last cycle of steps and form the second part of the desorbed gas mixture, which is a highly enriched xenon concentrate containing xenon, for example, from 62 to 68 vol. % and the minimum residual content of the first associated gases (for example, the methane content is from 23 to 28 vol.%, the rest is the remaining associated gases and impurities). As a result, in the last cycle of steps, the first accompanying gases remaining in the desorbed gas mixture are largely removed from the process and increase the xenon content in the highly enriched xenon concentrate, which improves the quality of the latter.

A possible embodiment of the present invention, in which the first part of the desorbed gas mixture, which is derived at the initial stage of the first desorption of the last cycle of steps, is partially returned to the initial gas mixture of the first cycle of steps. This increases the extraction efficiency of xenon.

A possible embodiment of the present invention, in which as the source of the gas mixture of the first cycle of steps using natural hydrocarbon gas mixture with a particularly low content of xenon in the amount of 10 ^-2 about. % or less. At the same time, at least four cycles of steps are performed, of which at least the second and third cycles of steps are performed similarly to the first cycle of steps, and during each subsequent cycle of steps (second, third, last cycles of steps), the gas mixture is used as the initial gas mixture accumulated in the corresponding closed volume when performing the corresponding previous cycle of steps (first, second and third cycles of steps, respectively).

After the subsequent cycles of the steps are completed, the last cycle of steps described above is performed, as a result of which a desorbed gas mixture is obtained, which is a highly enriched xenon concentrate containing xenon, for example, from 90 to 94 vol. %) and the residual content of the first accompanying gases (for example, the content of methane is from 2.5 to 4.0 vol.%, the rest of the remaining associated gases and / or impurities).

However, as described above, the authors of the present invention have experimentally established that the implementation of the first desorption at each subsequent cycle of steps (also, as indicated above for the first and last cycles of steps) occurs gradually, while at the initial stage of the first desorption of these cycles steps before desorption xenon successively desorb the remaining first associated gases, and then gradually desorb xenon. Therefore, at the initial stage of the first desorption of each subsequent cycle of steps, the first part of the desorbed gas mixture is formed, which has an increased concentration of the first accompanying gases and a reduced concentration of xenon compared to their concentration in the initial gas mixture of the corresponding cycle of steps. This first part of the stripped gas mixture is removed from the process. After this elimination, continue the first desorption of each subsequent cycle of steps and form the corresponding xenon-enriched second part of the desorbed gas mixture, which has a residual concentration of the first associated gases. This xenon-enriched second part of the desorbed gas mixture of each subsequent cycle of steps is directed to the corresponding closed volume, where they accumulate essentially until the release of xenon from the adsorbent stops. This significantly reduces the concentration of the first associated gases and increases the concentration of xenon in the desorbed gas mixture, which is accumulated in the corresponding confined volume, which improves the quality of highly enriched xenon concentrate.

Thus, with each subsequent cycle of steps (second, third, and last cycles of steps), as a result of desorption of xenon and first associated gases, after this elimination, a desorbed gas mixture enriched in xenon is obtained than with each previous cycle of steps. As a result, the first accompanying gases remaining in the desorbed gas mixture during each previous cycle of steps are successively removed from the process and achieve a significant increase in the xenon content in the corresponding desorbed gas mixture, which significantly improves the quality of highly enriched xenon concentrate.

A variant is possible in which the desorbed gas mixture, obtained at the initial stage of the first desorption of this cycle of steps, extracted during each subsequent cycle of steps, is partially returned to the original gas mixture of the corresponding previous cycle of steps.

After the subsequent cycles of steps are performed, the last cycle of steps described above is performed, as a result of which a desorbed gas mixture is obtained, which is a highly enriched xenon concentrate containing xenon, for example, from 96 to 98% by volume and a residual content of the first accompanying gases (methane content less than 1 vol %, the remaining remaining associated gases and / or impurities).

After the first desorption, when performing each cycle of steps, a second desorption is carried out, which ensures the removal of the second accompanying gases from the adsorbent, which ensures an improvement in the characteristics of the adsorbent for the implementation of further steps.

The desorbed gas mixture obtained in the last cycle of steps, which is a highly enriched xenon concentrate, for example, is pumped into cylinders and sent to the consumer.

In this case, the desorbed gas mixture obtained in the last cycle of steps, which is a highly enriched xenon concentrate, can be directed to fine cleaning of the remaining associated gases and / or impurities and to obtain pure xenon, which allows to obtain xenon with a purity of 99.9999. Fine cleaning of impurities can be carried out by any known method suitable for similar purposes.

Thus, the proposed method of obtaining highly enriched xenon concentrate allows you to expand the range of source gas mixtures by providing the possibility of using gas mixtures with low xenon content (for example, from 10 ^-2 to 10 ^-1 %) and particularly low xenon content as starting mixtures, (e.g., 10 ^-2 vol.% or less), and to the production of highly xenon concentrate as the primary target market product in industrial scale without limiting the number of its production previous and subsequent process, and improve the quality of highly xenon concentrate while reducing the cost of the desired product.

Another embodiment of the present invention relates to the proposed method of obtaining highly enriched xenon concentrate, in which a natural hydrocarbon gas mixture with a particularly low xenon content is used as the initial gas mixture of the first cycle of steps.

The proposed method in this embodiment is performed by successively carrying out at least four of the above described cycles of steps. The number of cycles of steps depends on the amount of xenon in the initial gas mixture of the first cycle of steps. The proposed method in this embodiment allows the use of the source gas mixture with a particularly low xenon content (10 ^-2 % by volume or less). The smaller the amount of xenon in the initial gas mixture of the first cycle of steps, the more cycles must be performed. The first, second and third cycles of steps are carried out sequentially and essentially the same. The difference between these cycles of steps lies in the amount of xenon and associated gases in the initial gas mixture of each cycle of steps.

In this embodiment, when performing the first cycle of steps, a natural hydrocarbon gas mixture is used as the source gas mixture, in which free oxygen is absent in the accompanying gases. In this case, at each cycle of steps, activated carbon is used as an adsorbent and separate desorption is carried out, including the first desorption, in which desorption of xenon and first associated gases, each of which has an activation energy of desorption, is less than xenon, and which is carried out by evacuating the adsorber at pressure and temperature, providing desorption of xenon, and the second desorption, at which the desorption of the second associated gases, each of which has an activation energy of deso, is performed More than xenon, and which is carried out by evacuating the adsorber at a pressure below the evacuation pressure of the adsorber at the first desorption, and at a temperature that ensures desorption of the accompanying gas having the highest activation energy of desorption from the second associated gases. In this case, at the initial stage of the first desorption of each cycle of steps, the first part of the desorbed gas mixture is formed, which is removed from the process, and as a result of continuing the first desorption after this withdrawal, the second part of the desorbed gas mixture is formed, which is sent to the corresponding closed loop in each of the first three cycles. the volume where they accumulate essentially until the release of xenon from the adsorbent stops, and during the second desorption of each cycle of steps, a desorbed gas mixture is obtained containing the sec e associated gases that are removed from the process. Moreover, at each subsequent cycle of steps, the corresponding second part of the desorbed gas mixture, accumulated in the corresponding closed volume of the corresponding previous cycle steps, is used as the initial gas mixture, and the second cycle of steps, after the first desorption after the elimination, is obtained in the last cycle of steps, representing is a highly enriched xenon concentrate.

When implementing this variant of the proposed method, a highly enriched xenon concentrate with a content of xenon from 96 to 98 vol. % and the residual content of the first associated gases (methane content in the amount of less than 1 vol.%, the rest of the remaining associated gases and / or impurities).

The implementation of this variant of the proposed method includes the above for the first, second, third and last cycles of steps (at least four cycles of steps) of the first variant of the present invention.

In the same way as described above, before the initial gas mixture is supplied to the adsorber, in the first cycle of steps, the initial gas mixture is pre-cleaned from drip liquids and mechanical impurities, and at each cycle of steps the pressure of the original gas mixture is stabilized from 6 to 10 bar .

Similarly to the above described, the first part of the desorbed gas mixture, derived at the initial stage of the first desorption of each subsequent cycle of steps, is partially returned to the original gas mixture of the corresponding previous cycle of steps.

As described above, a gas mixture is used as a natural hydrocarbon gas mixture, which contains at least methane and carbon dioxide as the first accompanying gases, and contains at least ethane, propane, butane as the second accompanying gases.

As described above, when each cycle of steps is performed, the first desorption is carried out by evacuating the adsorber at a constant pressure of 30 to 100 mbar and a constant temperature of 268 to 293 K, and the second desorption is carried out by evacuating the adsorber at a constant pressure of 2 to 30 mbar and a constant temperature 373 to 423 K.

Similarly to the above, the second part of the desorbed gas mixture, which contains highly enriched xenon concentrate, obtained in the last cycle of steps, is sent to fine cleaning of the remaining associated gases and / or impurities and to obtain pure xenon.

The use of the proposed method in the second embodiment of its implementation also provides a new functionality of the method, namely the possibility of obtaining highly enriched xenon concentrate as the main target commercial product on an industrial scale without limiting the amount of its production by previous and subsequent technological processes in improving the quality of highly enriched xenon concentrate by increasing there are xenon concentrations in it, as well as in expanding the range of initial hectares ovyh mixtures by enabling the use of gas mixtures of low and very low content of xenon, which provides the desired reduction of product cost while maintaining high xenon recovery rate (up to 40%).

This is due to the fact that the implementation of separate desorption improves the desorption of xenon from the adsorbent, makes it possible to use the xenon-enriched gas mixture in the previous cycle of steps as the initial gas mixture, which increases the xenon content in the desorbed gas mixture of the last cycle of steps and improves the quality of highly enriched xenon concentrate. In addition, the implementation of separate desorption during the execution of each cycle of steps ensures almost complete removal of the second accompanying gases from the initial gas mixture, since these gases are removed from the process during the execution of each cycle, and the sequential execution of at least four cycles of steps reduces the quantity in the target product first accompanying gases, as these gases, when performing adsorption of each cycle of steps, are only partially absorbed by the adsorbent, and partially these gases are removed from the adsorber with passing her gas mixture in the performance of each series of steps. In this case, the first associated gases absorbed by the adsorbent are first desorbed at the initial stage of the first desorption, since they have an activation energy of desorption less than xenon, and they are removed at the initial stage of desorption of each cycle of steps. All this reduces the amount of first and second accompanying gases in the target product and increases the xenon content, which improves the quality of highly enriched xenon concentrate, and also eliminates the need for additional technological processes, which reduces the cost of the target product. At the same time, sequential execution of at least four cycles of steps allows expanding the range of source gas mixtures by ensuring that gas mixtures with low and especially low xenon contents can be used without limiting the amount of production of highly enriched xenon concentrate by previous and subsequent technological processes, which allows essentially unlimited expansion of xenon production as the main target product.

In more detail the proposed method of obtaining highly enriched xenon concentrate in its variants will be described below when describing the operation of the plant for its implementation.

For a better understanding of the invention below are specific examples of the installation for the implementation of the proposed method of obtaining highly enriched xenon concentrate in different versions with reference to the accompanying drawings, in which:

FIG. 1 shows schematically an installation for carrying out the proposed method in the first embodiment;

FIG. 2 is a schematic representation of an installation for carrying out the inventive method in another embodiment.

Consider the first embodiment of the installation for the implementation of the first variant of the proposed method of obtaining highly enriched xenon concentrate (Fig. 1), in which the initial gas mixture of the first cycle of steps has a low xenon content and in which at least two cycles of steps are carried out sequentially.

As the source gas mixture, for example, a natural hydrocarbon gas mixture containing xenon in an amount of, for example, 1.5 × 10 ⁻¹ vol. % As the first accompanying gases, the specified natural hydrocarbon gas mixture contains methane, for example, in the amount of 94, 17 vol. % carbon dioxide and nitrogen. As the second accompanying gases, the specified natural hydrocarbon gas mixture contains ethane, propane and butane. This mixture contains impurities, for example, krypton and helium.

The specified gas mixture using a pipeline (a) with valves (not shown) is taken, for example, from a formed stream in an equipped natural field, which is located, for example, in Western Siberia. It is well known that the gas mixture of a natural field may contain mechanical impurities and dropping liquid, and may also have an elevated pressure and temperature. In this case, the gas mixture is sent to the initial gas mixture preparation unit of the first cycle of steps, where the selected gas mixture is pre-cleaned from drip liquids and mechanical impurities, respectively, in the filter coalescer and in the mechanical purification filter and stabilize pressure and temperature, respectively, from 6 to 10 bar and from 268 to 293 K for further use as the initial gas mixture of the first cycle of steps.

Installation for the implementation of the first variant of the proposed method contains the unit 1 preparation of the original gas mixture of the first cycle of steps, having, for example, filter 2 mechanical cleaning of the source gas mixture from mechanical impurities, filter coalescer 3 cleaning the source gas mixture from dropping liquid, pressure regulator 4 to stabilize the pressure of the source gas mixture to feed the corresponding adsorber of the first cycle of steps and the heat exchanger 5 to stabilize the temperature of the source gas mixture before delivery to the appropriate adsor EP first cycle steps; block 6 of the adsorbers of the first cycle of steps, containing at least two (first and second) identical adsorbers 7, 8, connected in parallel and working alternately; vacuum pump station 9 to reduce the pressure in the adsorbers 7, 8 of the first cycle of steps; a temperature stabilization system (not shown in the drawing) in adsorbers 7, 8 of the first cycle of steps; the buffer tank 10 (above, when describing the proposed method, it was called a closed volume) for accumulating a desorbed gas mixture of the first cycle of steps; a compressor 11 and a heat exchanger 12 for stabilizing, respectively, the pressure and temperature of the desorbed gas mixture of the first cycle of steps before submitting the last cycle of steps to the corresponding adsorber; the block 13 of the adsorbers of the last cycle of steps, containing at least two identical adsorbers 14, 15, connected in parallel and operating alternately; vacuum pump station 16 to reduce the pressure in the adsorbers 14, 15 of the last cycle of steps; a temperature stabilization system (not shown in the drawing) in adsorbers 14, 15 of the last cycle of steps. All movements of gas mixtures carried out using pipelines (a) with valves (not shown).

The proposed method can be carried out using a single adsorber, but in this case it is impossible to ensure a continuous process of obtaining highly enriched xenon concentrate, which means that it is more rational to use at least two adsorbers.

Each adsorber 7, 8 of the first cycle of steps is filled with an adsorbent. The absence of oxygen in the accompanying gases of the source gas mixture allows the use of activated carbon as the adsorbent, which has the highest xenon adsorption capacity of the known adsorbents, which improves the desorption of xenon and improves the quality of highly enriched xenon concentrate.

The proposed method is carried out by successively performing at least two cycles of steps (the first and last cycles of steps), which have been described above in detail and will be described below.

First, the prepared initial gas mixture is fed to the first adsorber 7 of block 6 of the adsorbers of the first cycle of steps. In the first adsorber 7, the components of the incoming source gas are adsorbed. At the outlet of the adsorber 7, the composition of the gas mixture not adsorbed out of the adsorber 7 during adsorption from the adsorber 7 is constantly measured. This is carried out using any known device suitable for similar purposes, for example, using a spectrometer, which is not shown in the drawing. The non-adsorbed gas mixture leaving the adsorber 7 until xenon appears in it is removed from the process. After the appearance of xenon at the outlet of the adsorber 7, the adsorption process in this adsorber 7 is stopped, and the prepared initial gas mixture is fed to the second adsorber 8 of block 1 of the adsorbers of the first cycle of steps, where they perform actions similar to those described in the first adsorber 7.

Then, in the first adsorber 7, separate desorption is carried out, in which the first desorption is first carried out (desorption of the first associated gases and xenon), and then the second desorption is carried out (desorption of the second associated gases).

The first desorption of the first cycle of steps is carried out by evacuating the adsorber 7 at a constant pressure of from 30 to 100 mbar (for example, 30 mbar) and a constant temperature from 268 to 293 K (for example, 268 K), providing desorption of xenon. This is carried out by means of a vacuum pumping station 9, with which the desorbed gas mixture is pumped out of the adsorber 7, and the system for stabilizing the temperature of the source gas mixture of the corresponding cycle of steps. As a result, when performing the first cycle of steps, a desorbed gas mixture enriched in xenon with a residual content of the first accompanying gases is obtained, which were partially removed from the adsorber 7 with the passing gas mixture. The first desorption is continued essentially until the release of xenon from the adsorbent stops.

Obtained when performing the first cycle of steps, a xenon-enriched (xenon content from 3.5 to 5.0 vol.%) A desorbed gas mixture with a residual content of the first accompanying gases (from 93, 0 to 94.0 vol.%, Of which the methane content is from 83, 0 to 91, 0 vol.%, The remaining remaining accompanying gases and impurities) are sent to the buffer tank 10, where they accumulate essentially until the release of xenon from the adsorbent stops. Thus, the accumulated desorbed gas mixture as compared with the initial gas mixture is enriched in xenon and has a lower content of the first associated gases.

However, since the implementation of the first desorption of the first cycle of steps occurs gradually, at the initial stage of the first desorption, the first associated gases are successively desorbed before xenon, and then gradually desorb xenon. As a result, at the initial stage of the first desorption of the first cycle of steps, the first part of the desorbed gas mixture is formed, which has an increased concentration of the first accompanying gases and a reduced concentration of xenon compared to their concentration in the initial gas mixture of the first cycle of steps. This first part of the stripped gas mixture is removed from the process. After this removal, the first desorption is continued and the second part of the desorbed gas mixture enriched in xenon (xenon content 3.1% by volume) is obtained, which has a residual concentration of the first accompanying gases (91.11% by volume, of which methane content is 89.7 vol.%, the rest remaining associated gases and impurities). In this case, this second part of the desorbed gas mixture is directed to the buffer tank 10, where it is accumulated essentially until the release of xenon from the adsorbent stops.

Then in the adsorber 7, the second desorption of the first cycle of steps is carried out, i.e. the desorption of the second associated gases. The second desorption of the first cycle of steps is carried out by evacuating the adsorber 7 at a constant pressure of 2 to 30 mbar (for example, 2 mbar), below the evacuation pressure of the adsorber 7 at the first desorption, and at a constant temperature from 373 to 423 K (for example, 373 K), providing the desorption component of the associated gas, which has the highest characteristic desorption energy from the second associated gases (in the example being described this is butane). The result is a desorbed gas mixture containing the second associated gases, which is removed from the process.

Next, the desorbed gas mixture from the buffer tank 10 is sent to the compressor 11, where they stabilize its pressure from 6 to 10 bar (for example, 7 bar), and then to the heat exchanger 12, where they stabilize its temperature from 268 to 293 K (for example, to 293 K ). Then the prepared desorbed gas mixture is sent to the block 13 of the adsorbers 14, 15 of the last cycle of steps as the initial gas mixture of the last cycle of steps.

First, the specified source gas mixture of the last cycle of steps is sent to the first adsorber 14 of the block 13 of the adsorbers of the last cycle of steps. In the first adsorber 14, the components of the initial gas mixture are adsorbed. At the outlet of the adsorber 14, the composition of the gas mixture leaving the adsorber 14 is continuously measured. This is carried out using any known device suitable for similar purposes, for example, a mass spectrometer, which is not shown in the drawing. The non-adsorbed gas mixture leaving adsorber 14 before xenon appears in it is removed from the process, for example, by means of a pipeline (a) with stop valves (not shown in the drawing). After the appearance of xenon at the outlet of the adsorber 14, the adsorption process in this adsorber 14 is stopped, and the prepared initial gas mixture of the last cycle of steps is fed to the second adsorber 15 of the block 13 of adsorbers of the last cycle of steps.

In the first adsorber 14, separate desorption is carried out, in which the first desorption is first carried out, i.e., desorption of xenon and first associated gases, each of which has a characteristic desorption energy less than xenon, and then the second desorption is carried out , each of which has an activation energy of desorption more than xenon.

The first desorption of the last cycle of steps is carried out by evacuating the adsorber 14 at a constant pressure of from 30 to 100 mbar (for example, 100 mbar) and a constant temperature from 268 to 293 K (for example, 293 K), providing desorption of xenon. This is carried out by means of a vacuum pumping station 16, by means of which the desorbed gas mixture is pumped out of the adsorber 14, and the system for stabilizing the temperature of the source gas mixture of the corresponding cycle of steps.

At the same time, during the first desorption in the last cycle of steps, a desorbed gas mixture is obtained containing highly enriched xenon concentrate (xenon content 35.04 vol.%) And residual, reduced compared to the initial gas mixture of the last cycle of steps, the content of the first accompanying gases (64.96 vol .%, where the methane content of 57.2% by volume, the rest of the remaining associated gases and impurities).

However, since the implementation of the first desorption of the last cycle of steps occurs gradually, at the initial stage of the first desorption, the first associated gases are successively desorbed before xenon, and then gradually desorb xenon. As a result, at the initial stage of the first desorption of the last cycle of steps, the first part of the desorbed gas mixture is formed, which has an increased concentration of the first associated gases and a lower concentration of xenon compared to their concentration in the initial gas mixture of the first cycle of steps. This first part of the stripped gas mixture is removed from the process. After this removal, the first desorption is continued and the second part of the desorbed gas mixture is obtained, which contains highly enriched xenon concentrate (xenon content is 65.4% by volume and residual concentration of first accompanying gases is 35.6% by volume, of which methane content is 25.3% vol.%, the rest remaining associated gases and impurities).

At the same time, the first part of the desorbed gas mixture obtained at the last cycle of steps, after its removal from the process, may be partially returned to the initial gas mixture of the first cycle of steps. This provides an increase in xenon extraction.

Then, in the first adsorber 14, the second desorption of the last cycle of steps is carried out, i.e. the desorption of the second associated gases, each of which has an activation energy for desorption more than xenon. The second desorption is carried out by evacuating the adsorber 14 at a constant pressure of 2 to 30 mbar (for example, 30 mbar) below the evacuation pressure of the adsorber 7 during the first desorption, and at a constant temperature from 373 to 423 K (for example, 423 K), providing desorption of the component accompanying gas, which has the highest activation energy of desorption from the second associated gases (in the described example it is butane). The result is a desorbed gas mixture containing the second associated gases, which is removed from the process.

In the event that a natural hydrocarbon gas mixture containing xenon in an especially low quantity is used as the initial gas mixture of the first cycle of steps, then at least four cycles of steps are performed, i.e. between the first and last cycles of steps, at least At least two intermediate cycles of steps (second and third cycles of steps), similar to the steps of the first cycle, and when performing each subsequent cycle of steps (second, third and last cycles of steps) as the initial gas mixture, Use the gas mixture accumulated in the corresponding buffer tank (closed volume) when performing the corresponding previous cycle of steps.

In this case, the first desorption of the first cycle of steps is carried out in the same way as described above, and the first desorption of the second and third cycles of the steps is carried out in the same way as the first desorption of the first cycle of steps.

When performing the second cycle of steps without removing the first part of the desorbed gas mixture, a xenon-enriched (xenon content of 16.4% by volume) get the desorbed gas mixture with the residual content of the first accompanying gases (83.6% by volume), of which methane content is 74.57% .%, the rest remaining associated gases and impurities).

When performing the second cycle of steps with the removal of the first part of the desorbed gas mixture, a xenon-enriched (xenon content of 24.2% by volume) is obtained with a residual content of the first associated gases (75.8% by volume), of which the methane content is 67.8% .%, the rest remaining associated gases and impurities).

When performing the third cycle of steps without removing the first part of the desorbed gas mixture, xenon-enriched (xenon content 72.1% by volume) get a desorbed gas mixture with a residual content of the first accompanying gases (27.9% by volume), of which methane content is 20, 9% .%, the rest remaining associated gases and impurities).

When performing the third cycle of steps with the removal of the first part of the desorbed gas mixture, xenon-enriched (xenon content 76.0% by volume) get the desorbed gas mixture with the residual content of the first accompanying gases (24.0% by volume), of which the methane content is 17.81% .%, the rest remaining associated gases and impurities).

Thus, the accumulated desorbed gas mixture of the third cycle of steps, as compared with the initial gas mixture of this cycle of steps, is enriched in xenon and has a lower content of the first accompanying gases.

Then, in the corresponding first adsorber of the second and third cycle of steps, the second associated gases are desorbed, each of which has an activation energy of desorption greater than that of xenon. The second desorption is carried out as described above. The result is a desorbed gas mixture containing the second associated gases, which is removed from the process.

Further, as described above, the last cycle of steps is carried out, in which, without removing the first part of the desorbed gas mixture, during the first desorption, a desorbed gas mixture containing highly enriched xenon concentrate with a xenon content of 92.0 vol. % and the residual concentration of the first associated gases 3.51 vol. %, of which methane content is 3, 49 vol. %, the rest of the remaining associated gases and impurities. And when removing the first part of the desorbed gas mixture during the first desorption get desorbed gas mixture containing highly enriched xenon concentrate with a content of xenon 98,0 about. % and the residual concentration of the first associated gases of 1.44 vol. % of them methane content 0,56 about. %, the rest of the remaining associated gases and impurities.

It is useful to direct the desorbed gas mixture obtained in the last cycle of steps containing highly enriched xenon concentrate to fine cleaning (not shown in the drawing) from the residual accompanying gases and / or impurities and to obtain pure xenon. This allows you to get xenon with a purity of 99.9999.

Thus, highly enriched xenon concentrate is obtained as a result of the implementation of one technological process as the main target commercial product on an industrial scale without limiting the amount of its production by previous and subsequent technological processes, which allows expanding the range of source gas mixtures to produce highly enriched xenon concentrate product. In addition, the application of the proposed method to obtain highly enriched xenon concentrate eliminates the need to use high temperatures, which significantly improves the quality of the target product. In this case, sequential execution of at least two cycles of steps allows expanding the range of source gas mixtures due to the possibility of using gas mixtures with low and extremely low xenon content without limiting the amount of production of highly enriched xenon concentrate by previous technological processes, which improves the quality of highly enriched xenon concentrate and reduces the cost price of the target product while maintaining a high xenon extraction rate. The implementation of this separate desorption of xenon and associated gases improves the desorption of xenon from the adsorbent during regeneration of the latter, makes it possible to use the xenon-enriched gas mixture obtained during the first cycle of steps as the initial gas mixture during the second cycle of steps, which ensures high quality xenon concentrate. In addition, the implementation of separate desorption during the execution of each cycle of steps ensures the maximum removal from the initial gas mixture of the second associated gases, each of which has an activation energy of desorption more than xenon. In this case, the sequential execution of at least two cycles of steps reduces in the target product the amount of first accompanying gases, each of which has an activation energy of desorption less than xenon, since these gases, when performing adsorption of each cycle of steps, are only partially absorbed by the adsorbent, and are partially in volume of the adsorber, as a result of which these gases are removed from the adsorber with the passing gas mixture during each cycle of steps. All this improves the quality of highly enriched xenon concentrate, eliminates the need for additional technological processes, which, in turn, reduces the cost of the target product, obtained as the main product.

Consider the second embodiment of the installation for the implementation of another (second) variant of the proposed method of obtaining highly enriched xenon concentrate (Fig. 2), in which the initial gas mixture of the first cycle of steps has a particularly low xenon content and in which four cycles of steps are carried out sequentially.

As the source gas mixture using natural hydrocarbon gas mixture containing xenon, for example, in the amount of 10 ^-2 about. % As the first accompanying gases, the specified natural hydrocarbon gas mixture contains methane, for example, in an amount of 94, 27% by volume. % carbon dioxide and nitrogen. As the second accompanying gases, the specified natural hydrocarbon gas mixture contains ethane, propane, butane, and the rest of the impurity.

At the same time in the initial gas mixture of the first cycle of steps in the accompanying gases there is no free oxygen, which allows at each cycle of steps as an adsorbent to use activated carbon, which improves desorption of xenon, which improves the quality of highly enriched xenon concentrate.

Specified natural hydrocarbon gas mixture using a pipeline (a) with valves (not shown in the drawing) is taken, for example, from the formed flow of the gas mixture in the equipped natural field, which is, for example, in Western Siberia.

As described above, the gas mixture of a natural field may contain mechanical impurities and dropping liquid, and may also have an elevated pressure and temperature. In this case, to use it as the initial gas mixture of the first cycle of steps, the selected gas mixture is preliminarily cleaned from drip liquids and mechanical impurities in the initial gas mixture preparation unit of the first cycle of steps and using the pressure regulator and heat exchanger stabilizes its pressure from 6 to 10 bar (for example, 7 bar) and temperature from 268 to 293 K (for example, 268 K) for further use as an initial gas mixture of the first cycle of steps.

Installation for the implementation of the second variant of the proposed method of obtaining highly enriched xenon concentrate (Fig. 2) contains the block 1 preparation of the initial gas mixture of the first cycle of steps, having, for example, filter 2 mechanical cleaning of the original gas mixture from mechanical impurities, filter coalescent 3 cleaning the original gas mixture from dropping liquid, pressure regulator 4 to stabilize the pressure of the source gas mixture before supplying the first cycle of steps to the corresponding adsorber and heat exchanger 5 to stabilize the temperature urs initial gas mixture to flow into the corresponding first adsorption cycle steps; block 6 of the adsorbers of the first cycle of steps, containing at least two (first and second) identical adsorber 7, 8, connected in parallel and working with a shift in time; vacuum pump station 9 to reduce the pressure in the adsorbers 7, 8 of the first cycle of steps; a temperature stabilization system (not shown in the drawing) in adsorbers 7, 8 of the first cycle of steps; buffer capacity 10 (above we called it a closed volume) for accumulation of the desorbed gas mixture of the first cycle of steps; a compressor 11 and a heat exchanger 12 for stabilizing, respectively, the pressure and temperature of the desorbed gas mixture of the first cycle of steps before it is supplied to the corresponding adsorber of the second cycle of steps; block 13 of the adsorbers of the second cycle of steps, containing at least two identical adsorber 14, 15, connected in parallel and working with a shift in time; vacuum pump station 16 to reduce the pressure in the adsorbers 14, 15 of the second cycle of steps; the temperature stabilization system in the adsorbers 14, 15 of the second cycle of steps (not shown in the drawing); a buffer tank 17 for accumulating the desorbed gas mixture of the second cycle of steps; the compressor 18 and the heat exchanger 19 to stabilize, respectively, the pressure and temperature of the desorbed gas mixture of the second cycle of steps until it is supplied to the third cycle of steps as the source gas mixture; block 20 of the adsorbers of the third cycle of steps, containing at least two (first and second) identical adsorbers 21, 22, connected in parallel and working alternately; vacuum pump station 16 to reduce the pressure in the adsorbers 21, 22 of the third cycle of steps; a temperature stabilization system (not shown in the drawing) in adsorbers 21, 22 of the third cycle of steps; a buffer tank 24 for accumulating the desorbed gas of the third cycle of steps, a compressor 25 and a heat exchanger 26 for stabilizing, respectively, the pressure and temperature of the desorbed gas mixture of the third cycle of steps before it is fed to the last cycle of steps as an initial gas mixture; block 27 of the adsorbers of the fourth cycle of steps, containing at least two identical adsorbers 28, 29, connected in parallel and working with a shift in time; vacuum pump station 30 to reduce the pressure in the adsorbers 28, 29 of the last cycle of steps; a temperature stabilization system (not shown in the drawing) in adsorbers 28, 29 of the last cycle of steps. All movements of gas mixtures carried out using pipelines (a) with valves (not shown).

The proposed method of obtaining highly enriched xenon concentrate in this embodiment is carried out by sequentially performing at least four cycles of steps (first, second, third and last cycles of steps), which were described in detail above and will be described below.

First, the previously prepared initial gas mixture is fed to the first adsorber 7 of the block 6 of the adsorbers of the first cycle of steps. In the first adsorber 7, the components of the incoming source gas are adsorbed. At the outlet of the adsorber 7, the composition of the non-adsorbed gas mixture emerging from the adsorber 7 is continuously measured. This is carried out using any known device suitable for similar purposes, for example, using a spectrometer, which is not shown in the drawing. The non-adsorbed gas mixture leaving the adsorber 7 until xenon appears in it is removed from the process. After the appearance of xenon at the outlet of the adsorber 7, the adsorption process in this adsorber 7 is stopped, and the previously prepared initial gas mixture is fed to the second adsorber 8 of the block 6 adsorbers of the first cycle of steps, where actions similar to those described in the first adsorber 7 are performed.

At this time, in the first adsorber 7, separate desorption is carried out, in which the first accompanying gases and xenon are first desorbed (first desorption), and then the second accompanying gases are desorbed (second desorption).

The first desorption is carried out by evacuating the adsorber 7 at a constant pressure of from 30 to 100 mbar (for example, 30 mbar) and a constant temperature from 268 to 293 K (for example, 268 K), ensuring desorption of xenon. This is carried out by means of a vacuum pumping station 9, with which the desorbed gas mixture is pumped out of the adsorber 7 and the pressure in the adsorber 7 of the first cycle of steps is reduced, as well as through a temperature stabilization system (not shown) in the adsorber 7 of the first cycle of steps. As this temperature stabilization system, any known system suitable for similar purposes can be used, for example, a shell-and-tube heat exchanger (not shown in the drawing).

At the initial stage of the first desorption, when performing the first cycle of steps, the first part of the desorbed gas mixture is formed with a high content of first associated gases and a xenon content lower than in the initial gas mixture of this cycle of steps. This first part of the desorbed gas mixture of the first cycle of steps is removed from the process and continues the first desorption of the first cycle of steps after the indicated elimination. As a result of the continuation of the first desorption after the said elimination, a xenon-enriched second part of the desorbed gas mixture of the first cycle of steps is formed, which is sent to the buffer tank 10. As a result, when performing the first cycle of steps in the buffer tank 10, the second part of the desorbed gas mixture of the first cycle of steps accumulates with a residual (reduced) content of the first accompanying gases in comparison with the initial gas mixture.

Then in the adsorber 7, a second desorption (desorption of the second associated gases) of the first cycle of steps is carried out. The second desorption of the first cycle of steps is carried out by evacuating the adsorber 7 at a constant pressure of 2 to 30 mbar (for example, 2 mbar), below the evacuation pressure of the adsorber 7 during the first desorption (desorption of xenon and the first accompanying gases), and at a constant temperature from 373 to 423 K (for example, 373 K), which ensures the desorption of the component of the accompanying gas, which has the highest activation energy of desorption from the second associated gases (in the described example it is butane). The result is a desorbed gas mixture containing the second associated gases of the first cycle of steps, which is removed from the process.

Next, the second part of the desorbed gas mixture of the first cycle of steps from the buffer tank 10 is sent to the compressor 11, where the pressure of this desorbed gas mixture is increased from 6 to 10 bar (for example, 7 bar), and then it is sent to the heat exchanger 12, where it stabilizes its temperature from 268 to 293 K (for example, 268 K).

Then this prepared desorbed gas mixture as the source gas mixture of the second cycle of steps is sent to the block 13 of the adsorbers of the second cycle of steps.

Thus, when performing the second cycle of steps, the xenon-enriched second part of the desorbed gas mixture accumulated in the buffer tank 10 when performing the first cycle of steps with pressure and temperature stabilized is used as the initial gas mixture.

First, the prepared initial gas mixture of the second cycle of steps is directed to the first adsorber 14 of the block 13 of the adsorbers of the second cycle of steps, where its components are adsorbed. At the outlet of the adsorber 14, the composition of the gaseous mixture leaving the adsorber 14 (passing through the adsorber 14) is continuously measured. This is carried out using any known device suitable for similar purposes, for example, using a mass spectrometer, which is not shown in the drawing. The non-adsorbed gas mixture leaving the adsorber 14 until xenon appears in it is removed from the process. After the appearance of xenon at the outlet of the adsorber 14, the adsorption process in this adsorber 14 is stopped, and the prepared initial gas mixture of the second cycle of steps is fed to the second adsorber 15 of the block 13 of the adsorbers of the second cycle of steps, where they perform actions similar to those described in the first adsorber 14.

Then, in the first adsorber 14 of the second cycle of steps, separate desorption of the second cycle of steps is carried out, in which the first desorption is first carried out, and then the second desorption is carried out.

The first desorption of the second cycle of steps is carried out by evacuating the adsorber 14 at a constant pressure of from 30 to 100 mbar (for example, 100 mbar) and a constant temperature of from 268 to 293 K (for example, 293 K), providing desorption of xenon. This is carried out using a vacuum pumping station 16 by pumping the desorbed gas mixture from the adsorber 14, as well as using a temperature stabilization system (not shown) in the adsorber 14 of the second cycle of steps. As this temperature stabilization system, any known system suitable for similar purposes can be used, for example, a shell-and-tube heat exchanger. The first desorption of the second cycle of steps continues essentially until the release of xenon from the adsorbent stops.

At the initial stage of the first desorption of the second cycle of steps, the first part of the desorbed gas mixture with a high content of first associated gases and a xenon content is lower than in the initial gas mixture of the second cycle of steps. This first part of the desorbed gas mixture of the second cycle of steps is removed from the process and continues the first desorption of the second cycle of steps after the indicated elimination. As a result of the continuation of the first desorption after the said elimination, a second part of the desorbed gas mixture of the second cycle of steps is formed, which is sent to the buffer tank 17. As a result, when the second cycle of steps is performed, the second part of the desorbed gas mixture of the second cycle of the second cycle accumulates in the buffer tank 17 with a residual (reduced) content of the first accompanying gases in comparison with the initial gas mixture. Thus, during the implementation of the second cycle of steps, as a result of the first desorption, a desorbed gas mixture enriched in xenon with a residual (reduced) content of the first accompanying gases is obtained as compared with the initial gas mixture of the second cycle of steps.

Then, in the adsorber 14, when performing the second cycle of steps, a second desorption is performed by evacuating the adsorber 14 at a constant pressure of 2 to 30 mbar (for example, 15 mbar), below the evacuation pressure of the adsorber 14 at the first desorption, and at a constant temperature of 373 to 423 K ( for example, 400 K), which ensures desorption of the component of the accompanying gas, which has the highest activation energy of desorption from the second associated gases (in the example described, this is butane). As a result of the second desorption of the second cycle of steps, a desorbed gas mixture is obtained containing the second associated gases of the second cycle of steps, which is removed from the process.

Next, the desorbed gas mixture of the second cycle of steps from the buffer tank 17 is sent to the compressor 18, where its pressure is increased from 6 to 10 bar (for example, 6 bar), and then it is sent to the heat exchanger 19, where it is stabilized from 268 to 293 K ( for example, 268 K). Then the prepared desorbed gas mixture of the second cycle of steps is sent to the block 20 of the adsorbers of the third cycle of steps, containing the first adsorber 21 and the second adsorber 22.

Thus, as the initial gas mixture of the third cycle of steps, a xenon-enriched desorbed gas mixture accumulated in the buffer tank 17 when performing the second cycle of steps, with pressure and temperature stabilized, is used.

First, the specified prepared xenon-enriched desorbed gas mixture from the buffer tank 17 as the initial gas mixture of the third cycle of steps is sent to the first adsorber 21 of the block 20 of adsorbers of the third cycle of steps. In the first adsorber 21 of the third cycle of steps, the components of the incoming source gas mixture of the third cycle of steps are adsorbed. At the outlet of the adsorber 21, the composition of the non-adsorbed gas mixture of the third cycle of steps exiting the adsorber 21 from the adsorber 21 is continuously measured. The non-adsorbed gas mixture leaving the adsorber 21 of the third cycle of steps until xenon appears in it is removed from the process. After the appearance of xenon at the outlet of the adsorber 21, the adsorption process in this adsorber 21 is stopped, and the prepared initial gas mixture of the third cycle of steps is fed to the second adsorber 22 of the block 20 adsorbers of the third cycle of steps, where they perform actions similar to those described in the first adsorber 21.

Then, in the first adsorber 21 of the third cycle of steps, separate desorption is carried out, in which the first desorption is first carried out, and then the second desorption is carried out.

The first desorption of the third cycle of steps is carried out by evacuating the adsorber 21 at a constant pressure of from 30 to 100 mbar (for example, 65 mbar) and a constant temperature of from 268 to 293 K (for example, 282 K), providing desorption of xenon. This is carried out by means of a vacuum pumping station 23, with which the desorbed gas mixture is pumped out of the adsorber 21, as well as by means of a temperature stabilization system (not shown) in the adsorber 21 of the third cycle of steps.

At the initial stage of the first desorption of the third cycle of steps, the first part of the desorbed gas mixture with a high content of first associated gases and a xenon content is lower than in the initial gas mixture of the third cycle of steps. This first part of the desorbed gas mixture of the third cycle of steps is removed from the process and continues the first desorption of the third cycle of steps after the indicated elimination. As a result of the continuation of the first desorption after the said elimination, a xenon-enriched second part of the desorbed gas mixture of the third cycle of steps is formed, which is sent to the buffer tank 24. When the third cycle of steps is performed, the second part of the desorbed gas mixture of the third cycle of the third cycle steps with the residual (reduced) content of the first associated gases as compared with the initial gas mixture.

Thus, during the implementation of the third cycle of steps, as a result of the first desorption, a desorbed gas mixture enriched in xenon with a residual (reduced) content of the first accompanying gases is obtained as compared with the initial gas mixture of the third cycle of steps.

Then in the adsorber 21 of the third cycle of steps, a second desorption is carried out by evacuating the adsorber 21 at a constant pressure of 2 to 30 mbar (for example, 30 mbar), below the evacuation pressure of the adsorber 21 during desorption of xenon and the first associated gases at the first desorption, and at a constant temperature from 373 to 423 K (for example, 423 K), which ensures desorption of the associated gas component, which has the highest activation energy for desorption from the second accompanying gases (in the example being described this is butane). The result is a desorbed gas mixture containing the second associated gases of the third cycle of steps, which is removed from the process.

Next, the desorbed gas mixture of the third cycle of steps from the buffer tank 24 is sent to the compressor 25, where its pressure is increased from 6 to 10 bar (for example, 10 bar, and then it is sent to the heat exchanger 26, where it stabilizes its temperature from 268 to 293 K, ( for example, at a temperature of 293 K.) Then the prepared desorbed gas mixture of the third cycle of steps is sent to the block 27 of the adsorbers of the last (fourth) cycle of steps, containing the first adsorber 28 and the second adsorber 29.

When performing the last cycle of steps, the xenon-enriched desorbed gas mixture accumulated in the buffer tank 24 when performing the third cycle of steps, with pressure and temperature stabilized, is used as the initial gas mixture.

First, the specified source gas mixture of the last cycle of steps is directed to the first adsorber 28 of the block 27 of the adsorbers of the last cycle of steps. In the first adsorber 28, the components of the incoming source gas mixture of the last step cycle are adsorbed. At the outlet of the adsorber 28, the composition of the gas mixture leaving the adsorber 28 is continuously measured. The non-adsorbed gas mixture leaving the adsorber 28 until xenon appears in it is removed from the process. After the appearance of xenon at the outlet of the adsorber 28, the adsorption process in this adsorber 28 is stopped, and the prepared initial gas mixture of the last cycle of steps is served as the initial gas mixture of the last cycle to the second adsorber 29 of the block 27 of adsorbers of the last cycle of steps, where they perform actions similar to those described in the first adsorber 28.

Then, in each adsorber 28, 29 of the last cycle of steps, separate desorption is carried out, in which the first desorption is first carried out, and then the second desorption is carried out.

The first desorption of the last cycle of steps is carried out by evacuating the adsorbers 28, 29 at a constant pressure from 30 to 100 mbar (for example, 30 mbar) and a constant temperature from 268 to 293 K (for example, 268 K), providing desorption of xenon. This is carried out by means of a vacuum pumping station 30, with which the desorbed gas mixture is pumped out of the adsorbers 28, 29, as well as by means of a temperature stabilization system (not shown) in the adsorbers 28, 29 of the last cycle of steps.

When the last cycle of steps is performed at the initial stage of the first desorption, in each adsorber 28, 29 the first part of the desorbed gas mixture is formed with a high content of first associated gases and a xenon content lower than in the initial gas mixture of the last cycle of steps. This first part of the desorbed gas mixture in the last cycle of steps is removed from the process and continues the first desorption of the last cycle of steps after the specified elimination. As a result of the continuation of the first desorption after the specified elimination in the last cycle of steps in each adsorber 28, 29 form the second part of the desorbed gas mixture of the last cycle of steps, which contains highly enriched xenon concentrate.

Then, in the adsorbers 28, 29, when the last cycle of steps is performed, a second desorption is performed by evacuating the adsorbers 28, 29 at a constant pressure of 2 to 30 mbar (for example, 20 mbar), below the evacuation pressure of the adsorber 28 at the first desorption of the last cycle of steps, and at a constant temperature from 373 to 473 K (for example, 411 K), providing desorption of the component of the accompanying gas, which has the highest activation energy of desorption from the second accompanying gases (in the described example it is butane). The result is a desorbed gas mixture containing the second associated gases, which is removed from the process.

Obtained during each subsequent cycle of steps, the first part of the desorbed gas mixture after it is removed from the process at each previous cycle of steps is partially returned to the original gas mixture of the corresponding previous cycle of steps.

When performing the first desorption of the first cycle of steps, a xenon-enriched (xenon content of 2.1% by volume) desorbed gas mixture with a residual content of the first accompanying gases (97.89% by volume) is obtained, of which methane content is 91.9% by volume, the rest associated gases and impurities).

When performing the first desorption of the second cycle of steps, a desorbed gas mixture enriched in xenon (xenon content 24.2% by volume) with a residual content of the first accompanying gases 75.8% vol. %, of which methane content is 67.8 vol. %, the remaining remaining associated gases and impurities).

When performing the first desorption of the third cycle of steps, a desorbed gas mixture enriched in xenon (xenon content 76.0 vol.%) With a residual content of the first accompanying gases 24.0 vol. %, of which the methane content is 17.81% by volume %, the remaining remaining associated gases and impurities).

When performing the first desorption of the last (fourth) cycle of steps, a desorbed gas mixture is obtained, which is a highly enriched xenon concentrate (xenon content is 98.0% by volume) and residual concentration of the first accompanying gases (1.44% by volume, of which methane content is 0 , 56 vol.%, The rest remaining associated gases and impurities).

Thus, with each subsequent cycle of steps, as a result of the first desorption, a desorbed gas mixture enriched with xenon is obtained than with each previous cycle of steps.

When performing the last cycle of steps, it is possible to direct the desorbed gas mixture, which is a highly enriched xenon concentrate, to fine purification from impurities and to obtain pure xenon with a purity of 99.9999.

Thus, the use of the proposed method ensures the production of highly enriched xenon concentrate as a result of a single technological process, in which highly enriched xenon concentrate is obtained as the main target commercial product on an industrial scale without limiting the amount of its production by previous and subsequent technological processes. mixtures for high enriched xenon concentrate, nachitelno simplify and reduce the cost of its production and ensure a significant reduction in the target cost of the product. In addition, the use of only one process to obtain highly enriched xenon concentrate eliminates the need to use high temperatures, which significantly improves the quality of the target product. In this case, the sequential execution of at least four cycles of these steps allows you to expand the range of source gas mixtures through the use of gas mixtures with a very low xenon content without limiting the amount of obtaining highly enriched xenon concentrate by previous technological processes, which greatly simplifies and reduces the cost of its production, as well as significantly reduces the cost of the target product while maintaining a high xenon extraction ratio (up to 40%). The implementation of separate desorption of xenon and associated gases improves the desorption of xenon from the adsorbent during regeneration of the latter, makes it possible to use the xenon-enriched gas mixture obtained during the performance of the corresponding previous cycle of steps for each subsequent cycle of steps ( up to 40%) and improving the quality of highly enriched xenon concentrate. In addition, the implementation of separate desorption during each cycle of steps ensures the maximum possible removal of associated gases, each of which has a characteristic adsorption energy greater than that of xenon, from the original gas mixture, which eliminates the need for additional technological processes, which, in turn, reduces the cost of the target product, obtained as the main product. In this case, the sequential execution of at least four cycles of steps reduces in the target product the number of first associated gases, each of which has a characteristic adsorption energy less than xenon, since these gases are only partially absorbed by the adsorbent during each cycle of these steps, and partially are in the volume of the adsorber, as a result of which, when performing each cycle of steps, these gases are removed from the adsorber with the passing gas mixture. In this case, during the implementation of the initial stage of the first desorption of each cycle of steps, the first part of the desorbed gas mixture, which contains a significant amount of the first associated gases, is removed from the process. All this increases the xenon content in the desorbed gas mixture, which is a highly enriched xenon concentrate, improves the quality of the highly enriched xenon concentrate, eliminates the need for additional technological processes, which, in turn, provides a significant reduction in the cost of the target product, obtained as the main product.

Claims (19)

1. A method of producing highly enriched xenon concentrate, which consists in performing a cycle of steps, including: directing the initial gas mixture containing xenon and associated gases to an adsorber pre-filled with an adsorbent, continuous measurement of the composition passing through the adsorber gas mixture at the outlet of the adsorber, the implementation of the adsorption of xenon and related gases to produce a gas mixture, which, before the appearance of xenon in it, is removed from the process, and after the appearance of xenon, the adsorption is stopped and t regenerate the adsorbent by performing desorption of xenon and associated gases, characterized in that at least two cycles of said steps are carried out sequentially, with each cycle of steps performing separate desorption, including the first desorption, at which desorption of xenon and first associated gases is performed, each of which has the activation energy of desorption is less than that of xenon, and which is carried out by evacuating the adsorber at pressure and temperature, providing desorption of xenon, and volts This is the desorption at which the second accompanying gases are desorbed, each of which has an activation energy of desorption greater than that of xenon, and which is carried out by evacuating the adsorber at a pressure below the evacuation pressure of the adsorber at the first desorption and at a temperature that desorbs the associated gas having the highest activation energy of desorption from the second associated gases, and during the first desorption of at least the first cycle of steps, form a desorbed gas mixture containing xenon and the first accompanying gases, which are sent to a closed volume, where they accumulate essentially until the release of xenon from the adsorbent stops, and during the second desorption of each cycle of steps they form a desorbed gas mixture containing the second accompanying gases, which are removed from the process, while at least in the last cycle of steps, a desorbed gas mixture accumulated in a closed volume of at least the first cycle of steps is used as the initial gas mixture, and during the first desorption of the last cycle of steps get desorbed gas mixture, which is a highly enriched xenon concentrate. 2. The method according to p. 1, characterized in that prior to feeding the source gas mixture to the adsorber, in the first cycle of steps, the source gas mixture is pre-cleaned from drip liquids and mechanical impurities, and at each cycle steps stabilize the pressure of the source gas mixture of the corresponding cycle steps 6 to 10 bar and its temperature is from 268 to 293 K. 3. The method according to p. 1, characterized in that at the initial stage of the first desorption of the first cycle of steps form the first part of the desorbed gas mixture, containing xenon in smaller quantities than in the original gas mixture of the first cycle of steps, which is removed from the process, and closed the volume directs the second part of the desorbed gas mixture, which is formed as a result of the continuation of the first desorption of the first cycle of steps after the specified elimination. 4. The method according to p. 3, characterized in that at the initial stage of the first desorption of the last cycle of steps form the first part of the desorbed gas mixture, containing xenon in smaller quantities than in the original gas mixture of the last cycle of steps, which is removed from the process, and highly enriched xenon concentrate is obtained in the second part of the desorbed gas mixture, which is formed as a result of the continuation of the first desorption of the last cycle of steps after the specified elimination. 5. The method according to p. 4, characterized in that the first part of the desorbed gas mixture, derived at the initial stage of the first desorption of the last cycle of steps, is partially returned to the original gas mixture of the previous cycle of steps. 6. The method according to p. 1, characterized in that as the source gas mixture of the first cycle of steps using a natural hydrocarbon gas mixture, in which there is no free oxygen in the accompanying gases, while using each activated cycle, activated carbon is used as an adsorbent. 7. The method according to p. 6, characterized in that as a natural hydrocarbon gas mixture using a gas mixture, which as the first accompanying gases contains at least methane and carbon dioxide, and as the second accompanying gases contains at least , ethane, propane, butane. 8. The method according to p. 7, characterized in that when performing each cycle of steps, the first desorption is carried out by evacuating the adsorber at constant pressure from 30 to 100 mbar and a constant temperature from 268 to 293 K, and the second desorption is carried out by evacuating the adsorber at constant pressure from 2 to 30 mbar and a constant temperature from 373 to 423 K. 9. The method according to p. 1, characterized in that as the source of the gas mixture of the first cycle of steps using natural hydrocarbon gas mixture containing xenon in an amount of 10 ^-2 % vol. And less, while performing at least four cycles of steps, from which at least the second and third cycles of steps are performed similarly to the first cycle of steps, and when performing each subsequent cycle of steps, the gas mixture accumulated in the corresponding closed volume when performing the corresponding previous one is used as the initial gas mixture th cycle of steps. 10. The method according to p. 9, characterized in that at the initial stage of the first desorption of each subsequent cycle of steps form the first part of the desorbed gas mixture containing xenon in smaller quantities than in the original gas mixture of the corresponding cycle of steps that is removed from the process, and a closed volume directs the second part of the desorbed gas mixture, which is formed as a result of the continuation of the first desorption of each subsequent cycle of steps after the specified elimination. 11. The method according to p. 10, characterized in that at the initial stage of the first desorption of each subsequent cycle of steps form the first part of the desorbed gas mixture containing xenon in a smaller amount than in the original gas mixture of the corresponding cycle of steps that is removed from the process, and highly enriched The xenon concentrate is obtained in the second part of the desorbed gas mixture, which is formed as a result of the continuation of the first desorption of the last cycle of steps after the specified elimination. 12. The method according to p. 11, characterized in that the first part of the desorbed gas mixture, derived at the initial stage of the first desorption of each subsequent cycle of steps, partially return to the original gas mixture of the corresponding previous cycle steps. 13. The method according to p. 1 or 11, characterized in that the second part of the desorbed gas mixture obtained during the last cycle of steps, which is a highly enriched xenon concentrate, is sent for fine cleaning of the remaining associated gases and / or impurities and obtaining pure xenon. 14. The method of obtaining highly enriched xenon concentrate, which consists in performing a cycle of steps, including: the direction of the original gas mixture containing xenon and associated gases in the adsorber pre-filled with the adsorbent, continuous measurement at the outlet from the adsorber composition, passing through the adsorber gas mixture, the implementation of the adsorption of xenon and related gases with obtaining a gas mixture, which before the appearance of xenon in this gas mixture is removed from the process, and after the appearance of xenon in it, adsorption regeneration of the adsorbent is stopped and carried out by performing desorption of xenon and associated gases, characterized in that at least four cycles of the above steps are performed, the first of which use a natural hydrocarbon gas mixture that contains xenon in the amount of 10 ^-2 as the initial gas mixture % and less and in which there is no free oxygen in the accompanying gases, while at each cycle of steps activated carbon is used as an adsorbent and separate Insorption, including the first desorption, at which desorption of xenon and first associated gases is performed, each of which has an activation energy of desorption less than that of xenon, and which is carried out by evacuating the adsorber at pressure and temperature, providing desorption of xenon, and a second desorption, at which perform desorption of the second associated gases, each of which has an activation energy for desorption more than xenon, and which is carried out by evacuating the adsorber at a pressure below the vacuum stabilization of the adsorber during the first desorption and at a temperature that ensures desorption of the accompanying gas, which has the highest activation energy for desorption from the second accompanying gases, while at the initial stage of the first desorption of each cycle of steps form the first part of the desorbed gas mixture containing xenon in a smaller amount than in the initial gas mixture of the corresponding cycle of steps, which is removed from the process, and as a result of the continuation of the first desorption after the specified elimination form the second part of desorbers This gas mixture, which in each of the first three cycles of steps is directed to the corresponding closed volume, where they accumulate essentially until the release of xenon from the adsorbent stops, and during the second desorption of each cycle of steps, they form a desorbed gas mixture containing the second associated gases, which are removed from the process, and in each subsequent cycle of steps, the corresponding second part of the desorbed gas mixture, accumulated in the corresponding confined volume corresponding to Following the previous cycle of steps, and in the last cycle of steps, as a result of continuing the first desorption after this elimination, a second part of the desorbed gas mixture is obtained, which is a highly enriched xenon concentrate. 15. The method according to p. 14, characterized in that prior to feeding the source gas mixture to the adsorber, in the first cycle of steps, the source gas mixture is pre-cleaned from drip liquids and mechanical impurities, and at each cycle steps stabilize the pressure of the source gas mixture of the corresponding cycle steps 6 to 10 bar and its temperature is from 268 to 293 K. 16. The method according to p. 14, characterized in that the first part of the desorbed gas mixture, derived at the initial stage of the first desorption of each subsequent cycle of steps, partially return to the original gas mixture of the corresponding previous cycle steps. 17. The method according to p. 14, characterized in that as a natural hydrocarbon gas mixture using a gas mixture, which as the first accompanying gases contains at least methane and carbon dioxide, and as the second accompanying gases contains at least , ethane, propane, butane. 18. The method according to p. 17, characterized in that when performing each cycle of steps, the first desorption is carried out by evacuating the adsorber at a constant pressure from 30 to 100 mbar and a constant temperature from 268 to 293 K, and the second desorption is carried out by evacuating the adsorber at constant pressure from 2 to 30 mbar and a constant temperature from 373 to 423 K. 19. The method according to p. 14, characterized in that the second part of the desorbed gas mixture obtained in the last cycle of steps, which is a highly enriched xenon concentrate, is sent to the fine cleaning of the remaining associated gases and / or impurities and obtaining pure xenon.

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