RU2685138C1 - Method of producing concentrate of xenon and krypton - Google Patents

Abstract

FIELD: technological processes.SUBSTANCE: invention relates to technological processes for producing inert gases and can be used to produce concentrate of xenon and krypton from natural gas, including associated petroleum gas and coal gas. Method is implemented by supplying natural gas and dispersed water into the reactor simultaneously, where thermobaric conditions are created to form a concentrate of gas hydrates of ethane, propane, isobutane and krypton. Further, they are decomposed to form a concentrate of xenon and krypton, wherein the pressure thermobaric conditions are in range of 0.1–20 MPa, and the temperature ranges from -10 to +20 °C (from 263 to -293 K). Besides, dispersed water in solid phase is supplied to reactor from above, forming counter flows of dispersed water and natural gas, or tangentially.EFFECT: technical result consists in improvement of output of target product – concentrate of xenon and krypton.3 cl, 4 dwg, 2 ex

Description

The invention relates to processes for the production of inert gases and can be used to obtain a concentrate of xenon and krypton from natural gas, including from associated petroleum gas and coal gas.

, проводят непрерывно при постоянном ее поступлении в многоступенчатый компрессор.Known gas hydrate method of separation of a mixture of gases [RU 2329092, C2, B01D 57/00, F25J 3/00 20.07.2008], which includes a stepwise process of hydration of the component gases of the original gas mixture, different temperature and pressure conditions for the formation of gas hydrates, followed by a stepwise dehydration process with the release of individual component gases from the gas mixture, while the source gas mixture with the component gases is fed to the first stage of a multi-stage compressor, where it is compressed at a pressure P1 equal to the hydrate formation pressure of the first comp nent of gas, then it is sent to the reactor, where the formation of gas hydrates occurs during the interaction of the first component gas with water, then in the first cyclone the gas hydrates are separated and sent for dehydration into the first tank to separate the first component gas, unreacted gas mixture with the remaining components - gases from the first cyclone are fed to the second stage of a multistage compressor, where it is compressed at pressure P2, then it is sent to the second reactor, where gas hydrates form at The action of the second gas component with water, then in the second cyclone, gas hydrates are separated and sent for dehydration into the second tank to separate the second gas component, the unreacted gas mixture with the remaining gas components from the second cyclone is fed to the next stage of the multi-stage compressor, and the cycle is again repeat, releasing the remaining components-gases, provided that the pressure at each subsequent stage is higher than the pressure at the previous stage, while the process of separation of the gas mixture, which has the size of molecules less than

, carried out continuously with its constant flow into the multistage compressor.

This technical solution allows you to organize a continuous process of separation of the gas mixture and to obtain individual components, gases with a high degree of purity.

However, the known method has a relatively high complexity.

There is also known a method for producing an inert gas concentrate [RU 2466086, C2, C01B 23/00, B01D 53/00, 10.11.2012], which provides for the preparation of an inert gas concentrate from raw materials in the form of a gas mixture, which use natural combustible mixtures produced fields from the group of gas, gas condensate, oil and gas condensate, oil and gas, gas and oil, oil, coal, gas hydrate, and inert gas concentrate is produced at least at one stage from extraction at the field to completion of processing, according to shey least one method from the group of: adsorption, absorption, gas diffusion, nozzle process, gas centrifuging, aerodynamic separation, swirl process, distillation, cryogenic rectification.

In the particular case of obtaining xenon concentrate is carried out either from field natural gas, or from field associated petroleum gas, or from field associated gas. In addition, obtaining xenon concentrate is carried out from at least one product of field preparation and processing from the group: from the main (purified) hydrocarbon gas, from the dried hydrocarbon gas, from the dry stripped gas (COG), from the wide fraction of light hydrocarbons (ShFLU ), from acid gases of a hydrocarbon gas purification installation from hydrogen sulphide, from flue gases of a sulfur production unit, from waste (reclaimed) gases from a hydrocarbon gas purification installation from hydrogen sulphide, from a sulfur-free hydrogen hydrocarbon gas, from waste (recyclable) gases of a hydrocarbon gas purification installation from carbon dioxide and oxide, from carbon dioxide and carbon monoxide purified from hydrocarbons from exhaust (recyclable) gases from a mercaptan gas purification installation, carbon disulfide and carbon disulfide, from purified from mercaptans, carbon disulfide and carbon monoxide of hydrocarbon gas, from waste (recyclable) gases of the plant for purification of hydrocarbon gas from nitrogen, from hydrocarbon gas purified from nitrogen and from the gaseous fraction in the concentration of hydrocarbon gases, residual gases from the unit for nitrogen and helium from the gas fraction separated natural gas liquids from a gaseous fraction of the hydrocarbon gas. At the same time, xenon concentrate is produced at gas-oil refining capacities, including pre-treatment plants for natural gas (UPPG), gas processing plants (GPPs), production of synthetic liquid hydrocarbons (including GTL technologies), liquefied gas plants (OGZ), at plants for helium production from natural gas.

The disadvantage of this technical solution is its relatively low efficiency, due to the relatively low yield of the target product.

The required technical result is to increase the yield of the target product - xenon concentrate and krypton from natural or associated petroleum gas.

The closest in technical essence and the achieved result is a method for producing xenon and krypton concentrate [RU 2640785, C1, СВВ 23/00, F25J 3/00 B01D 53/00, 11.01.2018], based on the supply of natural or associated petroleum gas to the reactor and, simultaneously with natural or associated gas, dispersed water is fed into the reactor and temperature and pressure conditions are created in the range from 0.1 to 20 MPa and in temperature in the range from -50 to + 50 ° C to form a concentrate of gas hydrates of ethane, propane , isobutane and krypton and subject them to decomposition eniyu to form a concentrate of krypton and xenon.

The disadvantage of the closest technical solution is its relatively low efficiency, due to the relatively low yield of the target product. This is caused by the instability of the conservation of water in dispersed form when it is fed into the reactor under the required temperature and pressure conditions. This does not allow for and maintain effective contact of dispersed water and gas. As a result, there is a decrease in the intensity of formation of a concentrate of gas hydrates of ethane, propane, isobutane and krypton, which ultimately leads to incomplete extraction of inert gases from natural and associated petroleum gas.

The task, which is solved in the invention, is aimed at increasing the efficiency of obtaining gas hydrates of ethane, propane, isobutane and krypton from natural or associated petroleum gas by creating conditions for a higher yield of the target product.

The required technical result is to increase the yield of the target product - xenon concentrate and krypton from natural or associated petroleum gas.

The problem is solved, and the required technical result is achieved by the fact that, in the method consisting in that, natural or associated petroleum gas and dispersed water are simultaneously fed into the reactor and create thermobaric conditions for the formation of a concentrate of gas hydrates of ethane, propane, isobutane and krypton and decompose them to form a concentrate of xenon and krypton, moreover, thermobaric pressure conditions are created in the range of 0.1 ... 20 MPa, according to the invention, thermobaric conditions according to temperature create in the range of -10 ... + 20 ° C (263 ... -293 K), moreover, natural or associated petroleum gas is fed into the reactor from the bottom, and dispersed water is fed into the reactor from above, forming their counter-flows, while dispersed water is fed into solid phase in the form of ice or snow.

In addition, the required technical result is achieved by the fact that gas hydrates are taken from the bottom of the reactor, and natural or associated petroleum gas is removed from the top after reacting with dispersed water in the solid phase.

In addition, the required technical result is achieved by the fact that, as dispersed water in the solid phase in the form of ice or snow, use is made of water obtained after decomposition of gas hydrates with subsequent conversion into dispersed water in the solid phase.

In addition, the required technical result is achieved by the fact that natural or associated petroleum gas and dispersed water are fed into the reactor tangentially.

The drawing shows:

in fig. 1 and FIG. 2 - examples of devices for implementing the proposed method;

in fig. 3 - phase diagram for the propane-water system (excess propane), where it is indicated: I - propane gas + water; II - propane gas + propane hydrate; III - liquid propane + water; IV - liquid propane + propane hydrate; V is gaseous propane + dispersed water in the solid phase; VI - liquid propane + dispersed water in the solid phase; zones A, B, C, D - temperature and pressure areas where propane gas hydrates are not formed;

FIG. 1 are designated: 1 - the heat exchanger, 2 - the reactor, 3 - the separation tank.

FIG. 2 are designated: 4 - the heat exchanger, 5 - the reactor, 6 - the segregation capacity.

The proposed method of producing xenon concentrate and krypton is implemented as follows.

Natural gas is sent to the reactor from below, where thermobaric conditions for the formation of gas hydrates of ethane, propane, isobutane, xenon and krypton are created by pressure in the range from 0.1 ... 20 MPa, in temperature - in the range -10 ... + 20 ° C (263 ... -293 K) At the same time, dispersed water in the solid phase is fed into the reactor from above or tangentially to the reactor vessel. During the contact time of dispersed water in the solid phase, gas hydrates of propane, ethane, xenon and krypton are formed in the reactor. The formation of methane gas hydrate does not occur and it remains in gaseous form. Dispersed water in the solid phase after contact settles down.

The resulting gas hydrates contain krypton and xenon in a concentration greater than in the source gas. Next, the gas stream containing solid phase gas hydrates is directed to the tank, where the decomposition of gas hydrates results in the evolution of gases and water. Water obtained after decomposition of gas hydrates can be reused with a preliminary conversion to dispersed water in the solid phase.

The above process in the device of FIG. 1 is implemented as follows. In the heat exchanger 1, the formation of fine snow. It is fed through the screw into the reactor 2, which receives natural gas under pressure from 1 to 200 atmospheres. At the first moment of time, the fluidization of snow occurs, then the molecules of propane, krypton, xenon, ethane, radon, isobutane, hydrogen sulfide are introduced into the crystal lattice of snowflakes, the gas hydrates of these gases are formed. Gas hydrates settle at the bottom of the reactor 2, then through the screw they enter the separation tank 3, where the destruction of gas hydrates occurs with the formation of water and inert gases concentrate (xenon, radon and krypton). The concentrate goes for further processing. Water enters the heat exchanger 1 to form ice.

The above process in the device of FIG. 2 is implemented as follows. In the heat exchanger 4, dispersed water is formed in the solid phase. It is fed through the screw into the reactor 5, which receives natural gas under pressure from 1 to 200 atmospheres. Natural gas is twisted in the reactor and reacts with dispersed water in the solid phase. Molecules of propane, krypton, xenon, ethane, radon, isobutane, hydrogen sulfide are introduced into the crystal lattice with dispersed water in the solid phase, forming gas hydrates of these gases. Gas hydrates settle at the bottom of the reactor 5 and then through the screw enter the separation tank 6, where the destruction of gas hydrates occurs with the formation of water and inert gases concentrate (xenon, radon and krypton). The concentrate is for further processing. Dispersed water enters the heat exchanger 4 to form ice.

FIG. 3 shows the phase diagram for the propane-water system (excess propane), where it is indicated: I - propane gas + water; II - propane gas + propane hydrate; III - liquid propane + water; IV - liquid propane + propane hydrate; V is gaseous propane + dispersed water in the solid phase; VI - liquid propane + dispersed water in the solid phase; zones A, B, C, D are the temperature and pressure regions where propane gas hydrates are not formed. These areas are interesting in that water and propane can be separated by further using propane.

FIG. 4 - thermobaric conditions for the formation of xenon gas hydrate are presented, from which it follows that the pressures at which the gas hydrates of propane xenon are formed are close in values, since propane in the gas is a macrocomponent

It is easy to see that the proposed method significantly increases the yield of the target product - xenon concentrate and krypton from natural or associated petroleum gas, and this achieves the required technical result. This is due to the fact that the effect of the instability of storing water in dispersed form when it is fed into the reactor is reduced. This allows you to make and maintain effective contact of dispersed water and gas. As a result, there is an increase in the intensity of formation of a concentrate of gas hydrates of ethane, propane, isobutane and krypton, which ultimately leads to more complete extraction of inert gases from natural and associated petroleum gas.

Claims (3)

1. A method of producing xenon and krypton concentrate, consisting in that natural gas and dispersed water are simultaneously fed into the reactor and create thermobaric conditions for the formation of ethane, propane, isobutane and krypton gas hydrate concentrate, and decompose them to form xenon and krypton concentrate, the pressure and pressure conditions are created in the range from 0.1-20 MPa, characterized in that the temperature and pressure conditions are created in the range from -10 to + 20 ° C (from 263 to -293 K), and dispersed water is fed into the reactor from above, forming a counter-flow of dispersed water and natural gas, or tangentially, while the dispersed water is fed in the solid phase. 2. The method of obtaining xenon concentrate and krypton according to claim 1, characterized in that gas hydrates are taken from the bottom of the reactor, and natural gas is removed from the top after reacting with dispersed water in the solid phase. 3. A method of obtaining a concentrate of xenon and krypton according to claim 1, characterized in that as dispersed water in the solid phase use water obtained after the decomposition of gas hydrates with subsequent conversion into dispersed water in the solid phase.

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