RU2640785C1 - Method for producing xenon concentrate and krypton from natural or associated petroleum gas - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method is implemented by feeding natural or associated petroleum gas into the reactor. Together with natural or associated gas, dispersed water is supplied into the reactor and thermal baric conditions are created by pressure in the range from 0.1 to 20 MPa and temperature in the range from -50 to +50°C to form a concentrate of ethane gas hydrates, propane, isobutane and krypton. They are further subjected to decomposition with formation of xenon concentrate and krypton.

EFFECT: increased yield of the end product.

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Description

The invention relates to technological processes for producing inert gases and can be used to obtain a concentrate of xenon and krypton from natural or associated petroleum 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 07/20/2008], including a stepwise process of hydration of the component gas of the source gas mixture, differing in the thermobaric conditions for the formation of gas hydrates, followed by a stepwise process of dehydration with the separation of the individual gas components from the gas mixture, while the source gas mixture with the gas components is fed to the first stage of a multistage compressor, where it is compressed at a pressure P1 equal to the hydration pressure of the first component gas nitrate, then it is sent to the reactor, where gas hydrates are formed during the interaction of the first gas component with water, then in the first cyclone gas hydrates are separated and sent to dehydration in the first container to separate the first gas component, unreacted gas mixture with the remaining components -gas from the first cyclone is fed to the second stage of a multistage compressor, where it is compressed at a pressure of P2, then it is sent to the second reactor, where the formation of gas hydrates occurs when The action of the second gas component with water, then in the second cyclone, gas hydrates are separated and sent for dehydration to the second container 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 multistage compressor, and the cycle again repeat, releasing the remaining gas components, provided that the pressure in each subsequent stage is higher than the pressure in the previous stage, while the process of separation of the gas mixture, in which the size of the molecules e exceeds

are carried out continuously with its constant entry into a multi-stage compressor.

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

However, the known method has a relatively high complexity.

The closest in technical essence and the achieved result is a method of producing an inert gas concentrate [RU 2466086, C2, C01B 23/00, B01D 53/00, 10.11.2012], which provides for the production of an inert gas concentrate from raw materials in the form of a gas mixture, the quality of which use natural combustible mixtures produced in the 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 before processing is completed by at least one method from the group: adsorption, absorption, gas diffusion, nozzle process, gas centrifugation, aerodynamic separation, vortex process, distillation, cryogenic distillation.

In the particular case, the production of xenon concentrate is carried out either from commercial natural gas, or from commercial associated petroleum gas, or from commercial associated coal gas. In addition, the production of xenon concentrate is carried out from at least one product of field preparation and processing from the group: from main (purified) hydrocarbon gas, from dried hydrocarbon gas, from dry stripped gas (SOG), from a wide fraction of light hydrocarbons (BFLH) ), from the acid gases of the installation for the purification of hydrocarbon gas from hydrogen sulfide, from the exhaust gases of the sulfur production unit, from the exhaust (utilized) gases from the installation for the purification of hydrocarbon gas from hydrogen sulfide, from purified from sulfur hydrogen from a hydrocarbon gas, from the exhaust (utilized) gases of a hydrocarbon gas purification plant from dioxide and carbon monoxide, from a hydrocarbon gas purified from dioxide and carbon monoxide, from exhaust (utilized) gases from a hydrocarbon gas purification plant from mercaptans, carbon disulfide and carbon monoxide, from purified from mercaptans, carbon disulfide and carbon monoxide of hydrocarbon gas, from the exhaust (utilized) gases of a plant for the purification of hydrocarbon gas from nitrogen, from a 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 and oil refining capacities, including pre-treatment plants for natural gas (UPPG), gas processing plants (GPP), production of synthetic liquid hydrocarbons (including GTL technologies), liquefied gas plants (OGZ), and helium production from natural gas.

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

The problem that is solved in the invention is aimed at improving the efficiency of production 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 and krypton concentrate from natural or associated petroleum gas.

The problem is solved, and the desired technical result is achieved by the fact that, in the method based on the supply of natural or associated petroleum gas to the reactor, according to the invention, dispersed water is simultaneously supplied to the reactor along with natural or associated petroleum gas and pressure and temperature conditions are created in the range 0 , 1 ... 20 MPa and in temperature in the range of -50 ... + 50 ° C for the formation of gas hydrates of ethane, propane, isobutane, xenon and krypton, from which xenon and krypton gas hydrates are used, which are used in as xenon and krypton concentrates.

The drawing shows:

in FIG. 1 - phase diagram for the propane-water system (excess propane), where: I - gaseous propane + water, II - gaseous propane + propane hydrate, III - liquid propane + water, IV - liquid propane + propane hydrate, V - gaseous propane + ice, VI - liquid propane + ice, zones A, B, C, D - temperature and pressure areas where gas propane hydrates are not formed (these areas are interesting in that water and propane can be separated with the further use of propane).

in FIG. 2 - thermobaric conditions for the formation of xenon gas hydrate, from which it follows that the pressures at which xenon propane gas hydrates are formed are close in value, since propane in the gas is a macrocomponent

The invention consists in the following.

Natural or associated petroleum gas (it is possible to use coal gas) is sent to the reactor, where they create thermobaric conditions for the formation of gas hydrates of ethane, propane, isobutane, xenon and krypton (see Fig. 1). At the same time, dispersed water is fed into the reactor. In the reactor, gas hydrates of propane, ethane, xenon and krypton are formed. The formation of methane gas hydrate does not occur and it remains in gaseous form.

Next, a gas stream containing solid-phase gas hydrates is sent to a cyclone, filter, etc., where gas hydrates are released. Gas hydrates are collected in a container at the bottom of the cyclone, and the main gas is directed into the pipeline from which it entered the reactor. The resulting gas hydrates contain krypton and xenon in a concentration higher than in the source gas. Their concentration is calculated from the following ratios.

Let (in specific units):

M is the mass of methane in 1 kg of natural gas;

E is the mass of ethane in 1 kg of natural gas;

P is the mass of propane and isobutane in 1 kg of natural gas;

Ш - mass of other gases in 1 kg of natural gas;

And - the mass of krypton and xenon in 1 kg of natural gas;

M + E + P + W + I = 1.

The share of inert gases in the source of natural gas will be:

,

,

After the separation of ethane, propane, isobutane and krypton and xenon in the form of gas hydrates and separation from the main gas stream, their share in the concentrate will be:

,

,

Dividing (2) by (1), we determine the increase in the concentration of krypton and xenon in the concentrate.

M + E + P + W + I / E + P + I.

For example, the proportion of ethane propane and inert gases in natural gas is 5%. The share of xenon let it be 0.15%.

100/5 = 20 times the concentration of propane; xenon concentration 100 / 0.15 = 667 times.

An inert gas concentration increased by 20 and 667 times.

Examples of specific performance

1. The reactor is fed with natural petroleum gas in the composition of the masses. %: methane - 96, ethane - 2, propane - 1.5, carbon dioxide - 0.3, xenon 0.2.

At a pressure in the reactor of 0.5 MPa, a temperature of 5 ° C and the dispersed water supply, gas hydrates of propane and xenon are formed.

After decomposition of gas hydrates, the concentrate contains 11.8% xenon and 88.2% propane. It follows that, the concentration of xenon increased by 11.8 / 0.2 = 59 times

2. Associated petroleum gas of mass composition is fed into the reactor. %: methane - 76, ethane - 5, propane - 10, carbon dioxide - 0.2, xenon 0.12, krypton 0.23.

At a pressure of 1.5 MPa, a temperature of 2 ° C and a dispersed water supply, gas hydrates, ethane, propane, xenon and krypton are formed.

After decomposition of gas hydrates, the concentrate contains 2.28% xenon and krypton and 97.72% ethane and propane.

The concentration of xenon and krypton increased by 2.28 / 0.35 = 6.5 times.

If in these conditions only xenon is isolated, then the following mass indices are obtained. %: methane - 76, ethane - 5, propane - 10, carbon dioxide - 0.2, xenon 0.12, krypton 0.23.

At a pressure of 0.5 MPa, a temperature of 5 ° C and the dispersed water supply, gas hydrates, propane and xenon are formed.

After decomposition of gas hydrates, the concentrate contains 1.28% xenon and krypton and 98.72% ethane and propane.

The concentration of xenon and krypton increased by 1.28 / 0.12 = 10.67 times.

It is easy to see that the proposed method significantly increases the yield of the target product — xenon and krypton concentrate from natural or associated petroleum gas, thereby achieving the required technical result.

Claims (1)

A method of producing a xenon and krypton concentrate based on the supply of natural or associated petroleum gas to the reactor, characterized in that dispersed water is supplied to the reactor simultaneously with natural or associated gas and the pressure and pressure conditions are created in the range from 0.1 to 20 MPa and temperature in the range from -50 to + 50 ° C for the formation of a concentrate of gas hydrates of ethane, propane, isobutane and krypton and they are subjected to decomposition with the formation of a concentrate of xenon and krypton.

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