Method for adsorbing and storing natural gas and methane, and a complex facility for carrying out the method (embodiment)

Abstract

This group of inventions relates to the gas industry, particularly onshore storage of natural gas, and can be used for the storage, distribution, and supply of natural gas, methane, or related petroleum gases, regardless of the geological and geographic characteristics of the complex's location. The strategic onshore storage complex provides energy-efficient and safe storage, distribution, and supply of natural gas, methane, and / or related petroleum gases in an adsorbed state over a wide range of temperatures and pressures. The method for adsorbing natural gas and methane in an onshore natural gas adsorption storage complex involves removing natural gas from a gas source, processing the natural gas, including purifying it from solids and foreign matter, and processing it in a microporous adsorbent material in a high-pressure tank of an onshore gas adsorption storage module. The purified gas is then passed through a natural gas processing unit until the gas source pressure is reached, and then through a natural gas compression unit until a gas storage pressure of 3 to 10 MPa is reached, and then the purified gas is filled into the gas storage unit directly from the gas source.

Description

[Technical field]

[0001] This group of inventions relates to the gas industry, in particular the onshore storage of natural gas, and can be used for the storage, distribution and supply of natural gas, methane or associated petroleum gas, regardless of the geological and geographical characteristics of the location of the complex. [Background technology]

[0002] In underground cavities in mineral salts washed with water, typically 100 kg / cm 2 Methods for storing compressed natural gas under pressures exceeding 100 million m are known (VA Mazurov, Subsurface Storage Facilities in Mineral Salt, Moscow, Nedra, 1982). 3 To store this amount of natural gas, 10,000 m3 of reservoir water must be removed at a depth of at least 600 m. 3 The construction of such a storage facility is very geologically / geographically and geophysically limited and is only possible in mineral salt deposits. Moreover, its construction requires considerable costs and time.

[0003] Methods are known for storing natural gas (NG) in a liquefied state (for example, GOST R 56352-2015 Petroleum and Natural gas Industries. Production, Storage and Handling of Liquefied Natural Gas). Liquefied natural gas (LNG) is a mixture of light hydrocarbons, nitrogen and carbon dioxide contained in NG, the main component of which is methane, which is technically liquefied by deep cooling to cryogenic temperatures (approximately minus 162 ° C) (thermodynamic conditions under which gas becomes liquid at pressures close to atmospheric pressure). Methane NG liquefaction is carried out using special cryogenic plants operating on the principles of throttle, expansion cycle, cascade, cooling and combined cycle. Technical liquefaction of natural gas sharply increases its density by 500-600 times over the density of gaseous substances under normal conditions. Thus, it provides the opportunity to effectively store and transport very large quantities of NG.

[0004] The storage of natural gas in a liquefied state is usually carried out using tanks consisting of an inner shell made of 12Cr18Ni10Ti corrosion-resistant steel, insulation made according to conventional cryogenic technology (powder insulation), and an outer shell made of cast-in-place reinforced concrete (IP Usyukin, Cryoengineering Plants, Machines and Devices. - Moscow: Consumer Goods and Food Industry, 1982, p. 275).

[0005] Disadvantages of this storage method include a high risk of fire or explosion due to stratification, or the formation of dense layers of liquid natural gas, resulting in rollover (a sudden increase in gas cushion pressure above the surface of the LNG), as well as the high cost of gas storage related to the need to cool the gas to cryogenic temperatures, liquefy it during storage, and heat it up to make it usable.

[0006] Also, a method for storing natural gas in a state bound by an external structure, such as gas hydrate (Russian Federation Patent No. 2293907, issued February 20, 2007, IPC F17C 11 / 00). When storing natural gas in the form of hydrate in a tank, an aqueous surfactant solution kept at a pressure 20-30% above the equilibrium pressure is used as the hydrate-forming aqueous medium to form pure methane hydrate at a given temperature.

[0007] Storage is carried out using storage tanks, typically steel vessels with a rated pressure of 2 MPa. A coil is installed inside the bottom of the vessel, and a coolant is pumped to the bottom to heat or cool the contents of the tank.

[0008] Such a storage method has many drawbacks related to the need to continuously maintain low temperatures during the storage process by pumping refrigerant and the need to use dedicated highly efficient gas drying systems before delivery to the consumer, as well as the low energy efficiency of the storage system, determined by the small specific capacity of gas storage.

[0009] The closest similar solution is the storage of natural gas in a compressed state using high-pressure gas holders (e.g. US Karabalin, FA Mamonov, KM Kabyldin, MM Yermekov, Transportation and Storage of Oil, Gas and Oil Products. - Almaty: TST-Company, 2005. - 509 pages).

[0010] Fixed-volume (high-pressure) gas holders serve as gas accumulator tanks at gas distribution stations of settlements, metallurgical or chemical enterprises. The pressure in such tanks can be up to 2 MPa. Structurally, high-pressure gas holders are metal welded or cast cylindrical or spherical tanks with different volumes. However, increased stored gas volumes are usually provided by combining several tanks into one gas system. A gas holder station is an engineering structure consisting of a number of gas holders or a set of their devices, designed to cover peaks of gas demand in settlements or industrial enterprises. Gas is supplied to the gas holder station from the MDS (Main Distribution Station) through a high-pressure relay trunk line. Then the gas from the gas holders is supplied to a circular and interconnected medium-pressure network, which allows the reservation of the capacity of the gas holder station. Control substations are built at some points of the medium-pressure network, where the supply to the low-pressure network is made.

[0011] The drawback of this type of storage is that it can take up to 20 m 3 (gas) / m 3 The specific capacity of the natural gas storage system is low, and the use of high-pressure gas holders increases the risk of fire and explosion. Summary of the Invention

[0012] The problem to be solved by the provided group of inventions is represented by the development of a simple, robust and efficient method for land-based adsorption storage of natural gas, methane and a complex for its implementation.

[0013] The technical achievements achieved by a group of inventions are represented by the simplicity of implementation, safety and energy efficiency of onshore adsorption storage of natural gas and methane, preserving the quality of natural gas and its calorific content, covering the natural gas needs of various consumers in conditions of sharply uneven consumption, regardless of the geological and geographical characteristics of the location of the complex.

[0014] Additional technological achievements are considered to be the reduction of the specific amount of metals in the gas storage modules and the opportunity to implement energy-saving gas filling and extraction procedures staged by pressure.

[0015] Additional technological achievements are the improvement of the feasibility and simplicity of production in complexes, the substantial reduction in production time in adsorption storage complexes, and the reduction in the costs of natural gas storage.

[0016] Said technical result is a complex for onshore adsorptive storage of natural gas, methane according to a first embodiment, comprising a gas processing unit, a gas compression unit and a gas storage unit with constant pressure, arranged in series, the gas storage unit comprises one or more onshore gas adsorptive storage modules, each of the modules being a high-pressure vertical cylindrical gas tank, the tank being designed in the form of a set of concentrically arranged cylindrical shells of different diameters, one of the shells being arranged inside another shell, with an annular gap, between which a microporous adsorbent material is filled to an extent not exceeding 97% of the gap volume, said adsorbent material being filled to an extent not exceeding 1 m of adsorbent material. 3 At least 155 per n m 3 of natural gas, provided that all shells are of equal thickness and the gas storage pressure in the tank increases from the periphery towards the center.

[0017] Said technical result is a complex for onshore adsorptive storage of natural gas, methane according to a second embodiment, comprising a gas processing unit, a gas compression unit and a gas storage unit with constant pressure, arranged in series, the gas storage unit comprising one or more onshore gas adsorptive storage modules, each of the modules being a high-pressure tank, the load-bearing walls of the tank being made of cast-in-place reinforced concrete reinforced with prestressed rods or having a combined design of a series of layers made of metal and cast-in-place reinforced concrete reinforced with prestressed rods, provided that the inner surface of the tank is lined with a gas barrier material, the tank is filled with a microporous adsorbent material in an amount not exceeding 97% of the tank's internal volume, and the adsorbent material is filled with a microporous adsorbent material in an amount not exceeding 1 m of adsorbent material.3 At least 155 per n m 3 This is achieved by accumulating natural gas.

[0018] Said technical result is a complex for onshore adsorption storage of natural gas, methane according to a third embodiment, comprising a gas processing unit, a gas compression unit and a gas storage unit with constant pressure arranged in series, the gas storage unit comprises one or more onshore gas adsorption storage modules, each of the modules being a high-pressure tank, the tanks being designed in the form of vertically arranged large-diameter metal gas pipes with an operating pressure of at least 3 MPa, provided that the upper and lower crowns of the pipes are closed with spherical covers and the lower part of the pipes is a closed liner for fixing the main part cast in cast-in-place concrete, the tanks are filled with a microporous adsorbent material in an amount not exceeding 97% of the tank's internal volume, said adsorbent material being filled with a volume of 1 m of adsorbent material. 3 At least 155 per n m 3 This is achieved by accumulating natural gas.

[0019] However, the microporous adsorbent may be granulated or compressed into a block form.

[0020] The gas processing unit further includes a purification section from solid contents and foreign matter mixtures, a natural gas stream methane enrichment section, and a C2+ hydrocarbon storage section, and the gas storage unit further includes a C2+ capture and storage module whose internal volume is filled with an adsorbent material having an ethane / methane separation factor of at least 2 and installed before the onshore gas adsorption storage module, a compensation tank for releasing pressure exceeding the operating pressure of the high-pressure tank, and a regeneration section of the onshore gas adsorption storage module connected to the high-pressure tank and the C2+ hydrocarbon capture and storage module.

[0021] The adsorbent material of the C2+ hydrocarbon capture and storage module may be granulated or compressed into a block form.

[0022] The onshore gas adsorption storage modules are mounted such that each is individually isolated from the gas source.

[0023] The technical achievement is a method for onshore adsorption storage of natural gas and methane, which comprises the steps of: extracting natural gas from a gas source; 3 At least 155 per n m 3 1 m of the microporous adsorbent in the high-pressure tank of the onshore gas adsorption storage module of the gas storage unit, and further charging the gas directly from the gas source into the gas storage unit until a gas storage pressure of 3 to 10 MPa is achieved; or, alternatively, removing the natural gas from the gas source, processing the natural gas in the natural gas processing unit, including purifying it from solid contents and foreign matter mixtures, and charging the gas storage unit with 1 m of the adsorbent in the high-pressure tank of the onshore gas adsorption storage module of the gas storage unit. 3 At least 155 per n m 3 the natural gas is then pumped through a natural gas compressor to a gas storage unit, where the natural gas is pumped through a microporous adsorbent to accumulate the natural gas, and then pumping the purified gas ... accumulate the natural gas, and then

[0024] Additionally, natural gas processing includes separation of natural gas into methane-enriched natural gas and C2+ hydrocarbon concentrates using cryogenic, adsorption, membrane, or combinations thereof. Processing of granular or block-compressed microporous adsorbents in high-pressure tanks involves purging with heated nitrogen at up to 0.05 MPa overpressure and 10 -4The process is carried out by drawing a vacuum until a dilution of less than 1000 MPa is achieved, and then purging the purified methane-enriched natural gas at an overpressure of 0.05-0.15 MPa. Within the gas storage unit, the purified gas is fed to a C2+ hydrocarbon capture and storage module whose internal volume is filled with an adsorbent having an ethane / methane separation factor of at least 2, and then the methane-enriched gas is sent to an onshore gas adsorption storage module for storage. The purified gas is fed to a C2+ hydrocarbon capture and storage module whose internal volume is filled with an adsorbent compressed into granular or block form.

[0025] The principles of the invention will be described by way of a detailed description of certain exemplary embodiments and the accompanying drawings, which are not intended to limit the invention. [Brief description of the drawings]

[0026] FIG. 1 shows an overall view of a complex for onshore adsorptive storage of natural gas and methane. FIG. 2 is a diagram of a complex for onshore adsorptive storage of natural gas and methane. FIG. 3 is a concentric adsorption pressure vessel with equal shell wall thickness of a complex for onshore adsorptive storage of natural gas and methane according to the first embodiment, a is a front view of the module, b is a cross-sectional view (AA), and c is a top view (C). FIG. 4 is a tank of a natural gas, methane adsorptive storage module with a composite wall made of cast-in-place reinforced concrete and metal sheets of a complex for onshore adsorptive storage of natural gas and methane according to the second embodiment, a is a front view of the module, b is a top view. FIG. 5 is a diagram of a composite wall made of cast-in-place reinforced concrete and metal sheets of natural gas of a natural gas, methane adsorptive storage module. FIG. 6-7 are natural gas adsorptive storage modules made of a main gas pipe of large diameter (1,420 mm), a is a front view, and b is a diagram of a complex for onshore adsorptive storage of natural gas and methane according to the third embodiment (A). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] A complex (embodiment) for onshore adsorptive storage of natural gas, methane includes: A: Natural gas processing unit B: Natural gas compression unit C: Gas storage unit 1: Natural gas source 2: Purification from solid contents Section Section 3: Purification from foreign matter mixtures 4: Compression device 5: Gas (natural gas, methane) onshore adsorption storage module connected to section 2 for solids content and purification from natural gas source 1 6: Natural gas stream methane enrichment section 7: C2+ Hydrocarbon Storage Section 8: Regeneration section of high pressure tank of onshore gas adsorption storage module 9: Additional tank connected to natural gas source 1 and onshore gas adsorption storage module 5 10: C2+ Hydrocarbon Capture and Storage Module connected to regenerated section 8 of the high pressure tank of the onshore gas adsorption storage module 5 11: Compression device 12: Consumers of methane-enriched natural gas 13: External steel shell 14: Internal steel shell 15: Gas supply pipeline 16: Adsorbent filler 17: Cast-in-place reinforced concrete tank 18: Internal steel shell 19: Adsorbent filler 20: Protective plate 21: Cover 22: Gas supply pipeline 23: Reinforced concrete wall 24: Internal steel shell 25: Metal protection material 26: Adsorbent 27: Vertical adsorption pipe column 28: Modular load-bearing wall 29: Module base plate 30: Gas supply pipeline 31: Crane for servicing adsorption pipe columns

[0028] In general, the natural gas storage methods provided are represented by the storage of gas in an adsorbed form. The use of natural gas adsorption storage methods can improve the energy efficiency and safety of natural gas storage.

[0029] The use of adsorbents in high pressure tanks allows for a reduction in filling pressure by more than a factor of two for the same amount of natural gas compared to tanks without adsorbents. Furthermore, the relative efficiency of adsorption storage (the ratio of the amount of gas stored in the storage system with and without adsorbents) increases as the pressure is reduced, allowing for energy-efficient compression of natural gas through reduced electricity costs and the use of simple compression equipment that is inexpensive to maintain. Furthermore, natural gas storage units can be filled from the main gas pipeline directly using a non-compression method or with minimal compression.

[0030] Furthermore, it is known that the adsorbate (natural gas in this case) in the microporous adsorbent remains in a nano-dispersed state within the adsorption force field, preventing the gas from being rapidly released if the tank is depressurized, i.e., preventing the possibility of achieving gas explosion conditions, making the disclosed method safer.

[0031] Another advantage of this natural gas storage method, compared to storage, for example, in underground gas or gas hydrate storage facilities, is the maintenance of gas quality and calorific content, which is of great importance when using the disclosed storage method, for example, to compensate for irregularities in export gas supplies or to use the gas as a gas engine fuel.

[0032] Complexes for onshore storage of natural gas based on the provided method (hereinafter referred to as complexes) can be very extensive, and depending on the feasibility of the principle of storage-scale modules or the amount of gas to be stored, it will be possible to place such complexes in the areas of both plants (for industrial gas fuel supply) and nearby villages, settlements, rural communities, cities and other residential areas, covering the demand for natural gas taking into account the dynamics of development. The complexes may be located in climatic zones with an average annual air temperature of minus 40 ° C to plus 30 ° C. It should be noted that the amount of natural gas stored in adsorbed form increases even at low temperatures up to the liquefaction temperature of methane, therefore the claimed complexes can be operated at temperatures below minus 40 ° C, provided that the functionality of all their units is generally guaranteed.

[0033] In general, the principle of operation of the complex implementing the method is as follows: gas from the gas source 1 is fed to the natural gas processing unit A, where it is treated in the purification section 2 from solid contents and in the purification section 3 from foreign matter mixtures, such as moisture, sulfur oxides, carbon dioxide. After purification, the gas is sent to the compression unit B and then to the gas storage unit C. In case of filling using the main gas pipeline, where the gas is under high pressure, the filling of the adsorption storage module 5 is carried out directly without using the compression device 4 of the compression unit B. In case the operating pressure of the gas source 1 is lower than the operating pressure of the adsorption storage module 5, the filling of the adsorption storage module 5 to the operating pressure of the gas source 1 is carried out without the compression device 4, and then using it. If the composition of the natural gas from the gas source 1 meets the requirements for the gas composition specified by the conditions of operation of the complex, it can be filled directly into the adsorption storage module 5, bypassing the natural gas processing unit. The gas feed from the adsorption storage module 5 is passed through a solids content purification filter in section 2 of the natural gas processing unit A and returned directly to the natural gas source 1 or, if necessary, via a compressor 4 of the natural gas compression unit B.

[0034] The adsorption storage module 5 of the gas storage unit C is a high-pressure tank or several high-pressure tanks that are coupled to the gas network in such a way that they can be individually disconnected from the gas network. This allows to increase the feasibility of storage, since in case of an accident, repair or regular maintenance of the high-pressure tank, it is not necessary to shut down the entire storage facility, it is enough to disconnect a single tank. Besides, such an approach may prove to be more versatile and economically feasible for gas consumers. The gas storage capacity can be set in strict accordance with the requirements and intended use of the complex, and an increase or decrease in capacity is not prevented. Also, depending on the progress of construction works (per module), a gradual start-up of storage is possible. Obviously, the number of modules can vary within wide limits, the upper limit is determined exclusively by land and economic reasons. It is important to note that the modular principle allows the consolidation of storage facilities and makes them typical, at least within the framework of an individual complex, which significantly reduces the costs of developing new design solutions and carrying out construction and installation works.

[0035] Each high-pressure tank 5 is manufactured in the form of a closed vessel capable of withstanding high pressures, in particular from 3 to 10 MPa. This range of operating pressures corresponds to the pressure values ​​of the storage system at which the most efficient operation of the adsorption system is observed. It is within this pressure range that the maximum difference in density between the adsorbed natural gas and the compressed gas is observed.

[0036] The high pressure tank 5 is equipped with a microporous adsorbent for storing natural gas, preferably its main component methane. The microporous adsorbents used in the high pressure tank, of the type represented by microporous carbon adsorbents, activated carbon, metal organic frameworks, sol-gels, metal organic gels, composite microporous materials, or mixtures thereof, have a porosity of at least 155 n m 3 (natural gas) / m 3(sorbent) must be able to be delivered to consumers. The sorbent must be in the form of granules, grains or blocks of various shapes, for example, tablets, cylinders, hexagonal columns, rectangular blocks, square blocks, rings, etc., in order to reduce the discharge of dust and sorbent from the high-pressure tank into the gas network. However, the high-pressure tank must be filled with sorbent to no more than 97% of the tank's internal volume. This is necessary because in the process of adsorption, adsorption and thermal deformation of the sorbent occurs with increasing temperature. The degree of expansion deformation of the overwhelming majority of sorbents during the adsorption of methane and ordinary hydrocarbons is not higher than for C5+ (the main component of natural gas) and does not exceed 1% in linear measurement or 3% by volume. Therefore, it is necessary to leave space in the tank for the sorbent to expand in order to reduce the possibility of mechanical damage to the tank due to uncompensated extra load on the walls, and at the same time reduce the possibility of destruction of the sorbent, which can lead to an increase in dust and, as a result, an increase in the discharge of dust into the gas transmission network of the complex.

[0037] In certain cases, natural gas is enriched with methane to increase its storage efficiency. When methane-enriched natural gas accumulates in the adsorbent, the amount of heavy hydrocarbons accumulated is significantly less, reducing the adsorption capacity of the adsorbent. This can increase the number of operating cycles (adsorption / desorption) of the tanks in the natural gas adsorption storage module, as the interval between regeneration of the adsorbent in the tanks is longer.

[0038] In this embodiment of the method, in addition to the methods described above, a methane enrichment section 6 is added to the natural gas processing unit A, where the capture of C2+ hydrocarbons and their transport to the C2+ hydrocarbon storage section 7 (Figure 2) is carried out using cryogenic, adsorption, membrane methods, or a combination thereof, and the extracted C2+ gas concentrated in individual containers is transported from there to consumers for processing or returned to the gas source. If necessary, the gas streams at the inlet and outlet of the methane enrichment section 6 should be subjected to periodic compositional analysis to verify the quality of the gas and, accordingly, whether the functioning of the equipment in the section meets the set requirements.

[0039] The high feasibility and maintainability of adsorption storage depend, among other things, on whether the initial adsorption properties of the microporous adsorbent material in the high-pressure tank of the gas adsorption storage module can be restored without removal or replacement (Figure 2).

[0040] The initial preparation of the natural gas adsorption storage module, including periodic regeneration during use, is carried out in the regeneration section 8 of the gas storage unit C. The system of the regeneration section is connected to the module tank in service to restore the adsorption properties of the adsorbent. The tank is purged with heated nitrogen under an overpressure of up to 0.05 MPa. To improve the adsorbent treatment, additional evacuation of the high-pressure tank to a dilution not exceeding 1 mbar is permitted. The high-pressure tank is then purged with purified methane-enriched natural gas under an overpressure of 0.05-0.15 MPa.

[0041] The purge pressure for treated tanks with natural gas is selected based on data from the commissioning period of the reservoir for gas adsorption storage modules and the expected temperature fluctuations in the period between the completion of the tank treatment and commissioning. The main criterion is to maintain the excess pressure in the tank in case of temperature drops, for example, during nighttime or seasonal changes.

[0042] Furthermore, the gas adsorption storage module has an additional tank 9 which is under an overpressure lower than the pressure in the high pressure tank 5 (Figure 2).

[0043] Tank 9 is designed to vent pressures in excess of the operating pressure from the high pressure tank 5 of the gas adsorption storage module 5. Tank 9 may have an operating pressure equal to or less than the operating pressure of the high pressure tank and may be used to deliver 155 n m 3 (natural gas) / m 3 The natural gas supply from the additional tank 9 may be provided to both the ancillary equipment of the complex and to the gas source (consumer) if a natural gas compression unit is used.

[0044] The improvement of the operating efficiency of the gas adsorption storage module by filling the high-pressure tank with methane-enriched natural gas can be carried out when a dual module storage is used, of which a first module 10 comprises an adsorbent (e.g., of the type represented by microporous carbon adsorbents, activated carbon, metal-organic frameworks, sol-gels, metal-organic gels, composite microporous materials, or mixtures thereof) in granular form or compressed into the form of a block for storing C2+ hydrocarbons, having an ethane / methane separation factor of at least 2, and a second module 5 of which comprises an adsorbent ... n m 3 (natural gas) / m 3 The second module has a total gas storage capacity greater than that of the first module, and the methane content in the stored natural gas serves as a criterion for the ratio between the two modules.

[0045] The operation of gas storage in such a design (Figure 2) means that the natural gas passing through the first storage module 10 is separated and enriched with natural gas components higher than C2+ completely or partially captured in the adsorbent in the high-pressure tanks of the first natural gas adsorption storage module, and the methane-enriched gas is transported to the second gas storage module 5 for storage. Further, the C2+ hydrocarbons are extracted into another container for enrichment and transported for processing or sent to consumers. Alternatively, in case of gas withdrawal from the storage module, the methane-enriched natural gas from the second module 5 is desorbed from the module 10 by counterflow, and the C2+ hydrocarbons enriched during filling and natural gas with a similar composition to the first one are supplied to the gas source 1.

[0046] In individual cases, it is necessary to fill methane-enriched natural gas, for example using natural gas vehicle fuel (methane) or a mobile adsorption terminal for supplying gas to gas sources remote from the main gas pipeline, in order to fill and drive automobiles. This may also be necessary during the filling of natural gas adsorption storage modules. To do so, the gas storage unit is equipped with a compression device 11 for filling consumers 12 (FIG. 2) if a natural gas processing and compression unit is not available for this.

[0047] To carry out the claimed natural gas storage method, an entire process system must be established, the central part of which will be the onshore gas adsorption storage module.

[0048] The main and most important structure of the complex is a special high-pressure tank with an adsorbent of the natural gas adsorption storage module, the characteristics of which must ensure high storage capacity values, as well as gas dynamic behavior of the withdrawal and filling of natural gas. In addition, the tank must be robust, safe and maintainable. Onshore natural gas storage complexes are especially relevant for the class of storage with a high upper limit of operating pressure, which can vary in wide intervals from 3 MPa to 10 MPa. The complex design must additionally take into account the thermodynamic characteristics of the adsorption and desorption processes, which facilitate the fluctuation of storage temperatures during filling and extraction of gas in the range from minus 40 ° C to plus 60 ° C.

[0049] To implement the claimed method for storing natural gas, a complex for onshore storage of natural gas is provided, including a natural gas processing, compression and storage unit, the natural gas storage unit comprising a high-pressure tank of a gas adsorption storage module, the gas adsorption storage module being designed in the form of a set of concentrically arranged cylindrical shells 13, 14 of different diameters, one of the shells being placed inside the other shell, with an annular gap, between which a microporous adsorbent material 16 is filled to an extent not exceeding 97% of the volume of the gap, the adsorbent material being filled to an extent of 1 m 3 At least 155 per (adsorbent) n m3 (natural gas) to consumers, except that all shells are of equal thickness and the gas storage pressure in the tank increases from the periphery to the center.

[0050] A feature of the claimed design is that it consists of a set of concentrically arranged cylindrical shells with an annular gap between them, which serves as a container for filling with gas through the gas supply pipeline 15 (Fig. 3). Such an implementation scheme of the high-pressure tank allows to create a structure in which all shells have equal thickness, but different overpressure values ​​in the container, formed by radial gaps between the shells, whose values ​​increase from the periphery towards the center. In this embodiment, the shell walls act as membranes, which are pressurized both from the inside and the outside, and the internal pressure p i is the external pressure p o The resulting pressure P res is the difference p i -p o This solution therefore allows the wall thickness to be optimized to smaller values ​​and the specific metal amount to be further reduced. To improve the spatial stiffness of the structure, it is possible to install radial reinforcements (Figure 3b).

[0051] The filling of such a high pressure tank is carried out as follows: first, the high pressure tank is completely filled until the operating pressure of the outer concentric vessel is reached, then the gas supply to the outer concentric vessel is stopped and gas is supplied to the remaining vessels until the operating pressure of the previous concentric vessel and then the next concentric vessel is reached, and this process is repeated until the central vessel is filled to the maximum operating pressure. Gas production is carried out in the reverse order starting with the production from the central vessel and gradually followed by the remaining concentric vessels from the center to the ends, at the appropriate natural gas production pressure value.

[0052] As an example of the claimed structure, calculation results of the main characteristics of concentric pressure vessels with the same shell thickness s = 100 mm, the inner diameter D of the shell varying from 5 to 25 meters and the pitch of 5 m are provided (Fig. 3, Table 1). In this example, the pressure in the tank increases from 1 MPa to 12 MPa.

[0053] [Table 1]

[0054] Field 1 gives the number of shells "from periphery to center", field 2 gives the diameter, and field 3 gives the allowable internal overpressure p acting on each shell. allow. and field 4 is the assumed value of the internal excess pressure inside each shell, P i Provides internal excess pressure P i The result of the verification of the loading conditions using is shown in field 5, and the inequality p allow. ≧P i -P i-1 Fields 6 and 7 contain the calculated area of ​​the base of the gap between the shells and the specific value of the accumulation capacity of the adsorbent bed for the specified pressure level.

[0055] The total "free" area at the base of the gap between the shells is 475 m 2 The area of ​​the base of a single tank with a diameter of 25 m is 15 m 2 The thickness of the concentric tank shell is 100 mm, but it is important to note that the wall thickness of a single tank D = 25 m at 3 MPa is already 207 mm. The geometric volume W of such a storage tank with a height of 20 m is 9,501 m 3 and the available gas storage capacity V CH4 is the expected V spec. -1.1 million m 3 Corresponds to cubic meters.

[0056] The shells of the claimed solution are loaded from both sides, allowing for an optimized wall thickness. Different operating pressure values ​​between the shells allow for staged filling of the onshore gas adsorption storage modules. The claimed solution therefore provides for energy-saving staged pressure filling and further extraction of natural gas and methane.

[0057] Another embodiment of the claimed invention is a complex for strategic onshore storage of natural gas, including a natural gas injection section, purification from solid contents, purification from foreign mixtures, compression, storage of the gas injected into the storage tank in adsorbed form under constant pressure for a defined period of time in a closed container and further withdrawal of the natural gas, whereby the natural gas adsorption storage module is designed as a pressure vessel 17, the bearing walls of which are made of cast-in-place reinforced concrete reinforced with prestressed rods or have a design of a combined series of layers made of metal and cast-in-place reinforced concrete reinforced with prestressed rods, furthermore, the inner surface of the structure is lined using a gas barrier material, and the tank is filled with an adsorbent material effective to accumulate an amount of natural gas not exceeding 97% of its internal volume.

[0058] Reinforced concrete modules can be manufactured both in reinforced concrete factories and on-site, avoiding the problems associated with transporting the large volumes of work-in-progress that are typical of metal gas storage tanks.

[0059] Compared to non-prestressed reinforced concrete, prestressed concrete can significantly reduce bending and provide improved crack resistance with comparable strength. Reinforcing bars made of high tensile strength steel are laid during reinforcement, tensioned with special equipment, and the concrete mix is ​​poured. Upon hardening, the prestressing force of the released steel wire or rope is transferred to the surrounding concrete, which compresses it. This generation of compressive stresses can partially or completely eliminate the tensile stresses caused by the operating loads.

[0060] To ensure the airtightness of reinforced concrete adsorbed natural gas storage modules, the inner surface can be lined with a gas barrier material, e.g. metal sheet, and ultrasonic testing of the welded joints can be additionally performed or special gas barrier membranes can be installed. The simultaneous use of reinforced concrete and thick metal plates in the tank walls turns the structure into a combined one when both layers (reinforced concrete and metal) support the load.

[0061] As an example, we present a natural gas adsorption storage module. The tank is a reinforced concrete structure with an internal metal liner made of sheet metal and has a nominal volume of 9,420 m. 3 The tank has a height of about 30 m and an internal diameter of 23 m, and operates under high pressure of up to 4 MPa (Figure 4). The tank's reinforced concrete walls are 1 m thick. The tank walls are spaced 1.5 m apart from each other in the modular wall sections in the plane perpendicular to the annular position of the rods. 2 An example of the wall structure of a natural gas adsorption storage module made of cast-in-place reinforced concrete combined with metal plates is shown in Figure 5. The tank 17 consists of an inner steel shell 18, a protective plate 20, a cover 21, and is filled with adsorbent 19, 26 filler.

[0062] The tank is filled with effective adsorbent to a level not exceeding 97% of its capacity and is at least 150% saturated with adsorbent at the tank operating pressure. n m 3 / m3 The amount of natural gas that such a tank can store is 1.41 million m 3 It is.

[0063] Figure 5 shows the construction of the combined modular walls 23 with an internal steel shell 24, cast-in-place walls with prestressed reinforcing rods, and a metal protective casing 25. The structural thickness of the modular walls, designed for 3.5 MPa, is over 1 meter.

[0064] The small dimensions of the tanks with joint walls made of cast-in-place reinforced concrete and metal sheets allow to create compact modules for the adsorption storage of natural gas. Thus, an area of ​​2-3 hectares can accommodate a strategic complex for onshore storage of natural gas, the adsorption-type natural gas storage module of which will comprise 9-12 tanks, the total volume of gas stored in it will be 12-16.5 million m3. 3 becomes gas.

[0065] If such a structure is selected, the number of gas supply utility lines can be optimized, the cost of storage can be significantly reduced, and its reliability can be improved.

[0066] More specifically, the following stages and sequence of construction and installation works for the construction of above-ground adsorption storage modules made of reinforced concrete and having connecting walls can be determined: area planning; excavation of a pit for the foundation intended for the placement of a natural gas adsorption storage module; construction of a pile field (if necessary); construction of the first layer of a monolithic grille (foundation slab); installation of a head with a protrusion of a reinforcing frame for casting of cast-in-place walls; installation of the second layer of a monolithic grille; installation of the central steel shell; installation of the cover; backfilling of the pit recess; installation of a gas supply pipeline; working platform for operation, installation of utility systems, construction of the architectural exterior, etc.

[0067] Another embodiment of the claimed invention is a complex for onshore adsorption storage of natural gas, methane, comprising a gas processing unit, a gas compression unit and a gas storage unit with constant pressure arranged in series, the gas storage unit comprises one or more onshore gas adsorption storage modules, each of the modules being a high-pressure tank, the tanks being designed in the form of vertically arranged large-diameter metal gas pipes with an operating pressure of at least 3 MPa, provided that the upper and lower crowns of the pipes are closed with spherical covers and the lower part of the pipes is a closed liner for fixing the main part cast in cast-in-place concrete, the tanks are filled with a microporous adsorbent material in an amount not exceeding 97% of the tank's internal volume, the adsorbent material being filled with a volume of 1 m of adsorbent material. 3 At least 155 per n m 3 of natural gas.

[0068] This increases the feasibility, maintainability and simplicity of production in complex facilities, and significantly reduces the production time of natural gas adsorption storage modules by using industrially manufactured elements from standard products in tank designs for which detailed processes and regulatory documentation have already been developed and extensive experience in their operation is available.

[0069] As an example, a variant of the pipeline gas storage facility is offered, in which a gas adsorption storage module is manufactured from a tank equivalent to a vertically placed main gas pipe with a diameter of 1,420 mm, designed for a pressure of 9.8 MPa according to GOST R 52079-2003 (Fig. 6). A pipe about 31 meters high is installed vertically on a reinforced concrete foundation (grill), the upper and lower crowns of the pipe are closed with spherical covers. The lower part of the pipe is a closed liner for fixing the main part, which together with the foundation monolithic grill is cast in cast-in-place concrete.

[0070] For the convenience of construction and maintenance, the natural gas adsorption storage module can be divided into two floors, upper and lower (Figs. 6-7). Approaches to the gas supply pipeline system and other systems for maintenance with a special operating platform are carried out on the lower floor. The upper floor is a reinforced concrete floor of cast-in-place design, part of whose load is transferred to the pipes themselves. A rail-mounted gantry crane 31 and an elevated operating platform are installed for maintaining the modules on the second floor.

[0071] Prior to installation, the pipes may already be filled with sorbent material effective for the storage of natural gas, however, placement of the sorbent material may also be performed already after vertical placement of the pipes using a crane in the form of special purpose briquettes.

[0072] Vertically arranged high-pressure pipe tanks are arranged in an array that ensures that the set capacity of the natural gas adsorption storage module is achieved. The optimality of this solution is ensured by the fact that the structure is made up of industrially produced standardized components, for which detailed process and regulatory documentation has already been developed and there is extensive experience of their operation. Moreover, fine-tuning of the storage capacity can be carried out at any time by introducing or removing new tanks (Figures 6-7).

[0073] Figures 6-7 show a schematic diagram of a complex for onshore adsorption storage of natural gas, equipped with vertical adsorption pipe columns 27, load-bearing walls 28 of the gas adsorption storage module, module foundation slab 29, gas supply pipeline 30 and a crane 31 for servicing the adsorption pipe columns. 51 pipes (1,420 mm main gas pipes) of the gas adsorption storage module are arranged in parallel.

[0074] This solution also offers many advantages for the development of a transport and logistics strategy for the delivery of cargo and materials to the construction site. Currently, a flowchart of the transport process and rigging has already been developed for the delivery of the main types of goods (pipes) for the production of tanks for natural gas adsorption storage modules.

[0075] The presented group of inventions simplifies the implementation by using typical components and modular design of the complex, improves energy efficiency during gas storage and filling due to lowering the filling pressure of the complex, ensures increased explosion safety during storage of natural gas as well as preservation of the quality and caloric content of natural gas by storing the gas in pressurized tanks filled with special nanoporous adsorbents that prevent gas and environmental pollution and ensure nano-dispersion of natural gas in micropores (each pore contains 20-30 molecules). This prevents the sudden release of gas during depressurization of the container due to gas diffusion in micropores with high heat absorption capacity, which in turn helps suppress explosive reactions. They also provide an endothermic effect during gas production, which suppresses the "cooling down" of the material in case of gas discharge. The presented group of inventions guarantees the possibility of energy-saving gas filling and extraction in stages by pressure, reduction of the specific metal content of the storage modules as well as improved feasibility and simplicity of manufacturing the complex, substantial reduction in the manufacturing time of gas adsorption storage modules, cost improvement of gas adsorption storage modules and reduction of natural gas storage costs through the use of modular structures based on the application of typical industrial solutions.

Claims

1. A complex for onshore adsorption storage of natural gas, methane, comprising a gas processing unit, a gas compression unit and a gas storage unit with constant pressure, arranged in series, said gas storage unit comprising one or more onshore gas adsorption storage modules, each of said modules being a high-pressure vertical cylindrical gas tank, said tanks being designed in the form of a set of concentrically arranged cylindrical shells of different diameters, one of said shells being arranged inside another of said shells, with an annular gap, between which a microporous adsorbent material is filled to an extent not exceeding 97% of the volume of said gap, said adsorbent material being filled to an extent not exceeding 1 m of said adsorbent material. ３ At least 155 nm per ３ of natural gas, provided that the thickness of all said shells is equal and the gas storage pressure in said tanks increases from the periphery towards the center.

2. 10. The complex of claim 1, wherein the microporous adsorbent material is granulated or compressed into a block form.

3. 2. The complex of claim 1, wherein the gas processing unit includes a purification section from solid contents and foreign matter mixtures, a natural gas stream methane enrichment section, and a C2+ hydrocarbon storage section, and the gas storage unit further includes a C2+ capture and storage module whose internal volume is filled with an adsorbent material having an ethane / methane separation factor of at least 2 and installed in front of the onshore gas adsorption and storage module, a compensation tank for releasing pressure exceeding the operating pressure of the high-pressure tank, and a regeneration section of the onshore gas adsorption and storage module connected to the high-pressure tank and the C2+ hydrocarbon capture and storage module.

4. 4. The complex of claim 3, wherein the adsorbent material of the C2+ hydrocarbon capture and storage module is granulated or compressed into a block form.

5. 10. The complex of claim 1, wherein the onshore gas adsorption storage modules are mounted such that each is individually decoupled from the gas source.

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