Composition, adsorption storage device containing the same, and associated gas recovery system

Abstract

The application provides a composition, an adsorption storage device containing the same and an associated gas recovery system. The composition comprises a multi-stage pore MOFs-based composite phase change material and an adsorbent material, the adsorption storage device is an adsorption storage tank filled with the composition as a bed layer. The associated gas recovery system mainly comprises a pressurization unit, a cooling condensation dehumidification unit and an adsorption storage unit, and the adsorption storage unit is the adsorption storage device. The associated gas recovery system can realize a single-lift well associated gas recovery process of medium pressure-low temperature-phase change temperature control-adsorption storage, so that the single-lift well associated gas with small gas volume, low casing pressure and far distance from a gathering station can be recovered at low cost and high efficiency under low pressure (specifically 2-4 MPa).

Description

Technical Field

[0001] The present invention belongs to the technical field of associated gas recovery, and in particular relates to a composition, an adsorption storage device containing the composition, and an associated gas recovery system. Background Art

[0002] Associated gas from oilfields is typically rich in a mixture of methane and other low-molecular-weight alkanes. During crude oil extraction, large amounts of this gas are vented or burned, resulting in not only energy waste but also environmental pollution and an exacerbation of the greenhouse effect. Therefore, recovering associated gas can achieve the triple benefits of reducing carbon emissions, lowering volatile organic compounds (VOCs), and recovering resources. This is particularly significant in the current response to global climate change and the development of a low-carbon economy.

[0003] Oil pipe connection technology is the most commonly used associated gas recovery technology in oil fields. It can automatically recover casing gas where the casing pressure exceeds the back pressure. This technology is characterized by easy installation and simple structure. However, this technology requires the use of crude oil gathering pipelines, making it difficult to recover associated gas where the casing pressure is less than the back pressure. In addition, the check valve is prone to freezing and blocking in winter, so the application scope of this technology is significantly limited, making it difficult to promote in remote wells.

[0004] In addition to process wells, oil fields also contain a large number of single-pull wells. The associated gas volume of these wells is unstable, the locations are scattered, and they are far from the pipeline system. Due to the lack of efficient and economical recovery technologies, their development and utilization have long been unrealized, resulting in significant resource waste and environmental pollution. For example, combustion of associated gas is a very common recovery method. The recovered associated gas can be used to heat water-jacket furnaces, multi-purpose tanks in pull wells, and duty rooms and injection and production stations, saving electricity. However, the combustion process is generally prone to substandard emissions, causing environmental pollution. Due to the large differences in basic parameters such as pressure, production, and stable production period of scattered associated gas, the recovery methods for small amounts of scattered associated gas are still in the exploratory stage, and no widely applicable, cost-effective recovery technology has yet to be widely adopted.

[0005] Compared with compressed natural gas (CNG) technology, the storage pressure of adsorbed natural gas (ANG) technology is lower, and has the characteristics of safe, flexible, convenient storage mode. ANG can be designed flexibly according to the resource and regional characteristics to improve the utilization efficiency of natural gas, so the ANG with superior performance has strong economic advantages and market competitiveness. With the in-depth research of ANG technology, certain achievements have been made in the aspects of adsorbent research and development, tank design, heat effect inhibition, etc. Studies have shown that ANG recovery technology can use microporous adsorbent material to adsorb methane molecules at room temperature and medium pressure (3-5 MPa). The storage pressure of ANG at room temperature is only 1 / 5 of CNG, and the storage and transportation capacity of the two is equivalent. The investment and operating cost of ANG is 48% lower than that of CNG, the tank material and shape are selective, and the safety factor is high, so ANG has good economy and safety. However, the adsorption heat effect of the adsorbent restricts the development of ANG technology: during the charging process, the kinetic energy of the methane molecules adsorbed on the surface of the adsorbent is converted into heat energy, which causes the temperature of the adsorbent to rise and the adsorption capacity of methane to decrease; during the discharging process, the methane molecules need to absorb energy during the desorption process, which causes the temperature of the adsorbent to decrease and the desorption capacity to decrease, and the cushion gas to increase. Therefore, it is urgent to develop a single-lift well small gas scattered associated gas recovery technology with wide application range and high economic efficiency. SUMMARY

[0006] In order to solve the above problems, the purpose of the present application is to provide an associated gas recovery system, and realize a medium pressure-low temperature-phase change temperature control-adsorption storage associated gas recovery process, so as to realize efficient recovery of single-lift well associated gas with small gas volume, low casing pressure and long distance from the gathering and transportation station at low cost under low pressure (specifically 2-4 MPa).

[0007] In order to achieve the above purpose, the first aspect of the present application provides a multi-level pore MOFs (metal organic framework compound) based composite phase change material, the second aspect of the present application provides a preparation method of the multi-level pore MOFs based composite phase change material, the third aspect of the present application provides an application of the multi-level pore MOFs based composite phase change material in adsorption of VOCs, the fourth aspect of the present application provides a composition, the fifth aspect of the present application provides an adsorption storage device, the sixth aspect of the present application provides an associated gas recovery system, and the seventh aspect of the present application provides an associated gas recovery process.

[0008] Specifically, the first aspect of the present application provides a multi-level pore MOFs based composite phase change material, which comprises a multi-level pore MOFs material with micropores, mesopores and macropores at the same time, and a phase change material loaded in the macropore channel of the multi-level pore MOFs material.

[0009] Preferably, the ratio of the micropore volume, mesopore volume and macropore volume of the multi-level pore MOFs material is 1-4:1-2:1.

[0010] Preferably, the specific surface area of ​​the multi-level porous MOFs material is 600-1700 m 2 / g.

[0011] Preferably, the phase change material is selected from one or more of polyols, fatty acids, linear alkanes and paraffins.

[0012] Preferably, the polyols are polyethylene glycol and / or neopentyl glycol.

[0013] Preferably, the fatty acid is selected from one or more of lauric acid, stearic acid, palmitic acid and pentadecanoic acid.

[0014] Preferably, the straight-chain alkane is selected from one or more of n-tetradecane, n-hexadecane and n-octadecane.

[0015] A second aspect of the present invention provides a method for preparing the above-mentioned multi-level porous MOFs-based composite phase change material, the preparation method comprising the following steps:

[0016] (1) mixing a first metal salt with water to obtain a first metal salt solution;

[0017] (2) mixing the template, the first organic ligand, and the first organic solvent to obtain a first organic phase solution;

[0018] (3) mixing the first metal salt solution with the first organic phase solution, and then performing a first reaction. After the reaction is completed, the solid-liquid separation is performed, and the obtained solid is washed and activated in sequence to obtain a hierarchical porous MOFs material;

[0019] (4) Mixing the phase change material with a first organic solvent to obtain an organic phase change material solution, and placing the multi-level porous MOFs material in the organic phase change material solution for immersion.

[0020] Preferably, the first metal salt is one or more selected from the group consisting of aluminum chloride hexahydrate, copper acetate monohydrate, chromium nitrate nonahydrate, zinc nitrate hexahydrate, zirconium chloride and nickel chloride hexahydrate.

[0021] Preferably, the content of the first metal salt in the first metal salt solution is 5-50 g / L.

[0022] Preferably, the template is selected from one or more of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, hexadecyltrimethylammonium bromide, sodium dodecylbenzenesulfonate and N,N,N,N-tetramethylethylenediamine.

[0023] Preferably, the first organic ligand is selected from one or more of 2-methylterephthalic acid, 2-aminoterephthalic acid, 2-nitroterephthalic acid, 2-sulfonateterephthalic acid, 2,3-dihydroxyterephthalic acid, terephthalic acid, phthalic acid, trimesic acid, 2,5-thiophenedicarboxylic acid and triethylenediamine.

[0024] Preferably, the first organic ligand is selected from one or more of 2-aminoterephthalic acid, 2,5-thiophenedicarboxylic acid, trimesic acid, terephthalic acid and triethylenediamine.

[0025] Preferably, the first organic solvent is selected from one or more of methanol, ethanol, N,N-dimethylformamide, dichloromethane and 1,2-dichloroethane.

[0026] Preferably, the content of the template in the first organic phase solution is 10-80 g / L, and the content of the first organic ligand is 30-150 g / L.

[0027] Preferably, the molar ratio of the first metal salt, the template and the first organic ligand is 1:0.03-1:1-2.

[0028] Preferably, in step (3), the conditions of the first reaction include: temperature of 20-160° C., and time of 6-18 h.

[0029] Preferably, the conditions of the first reaction include: temperature of 40-110° C. and time of 8-16 h.

[0030] Preferably, in step (3), the activation conditions include: temperature of 80-180° C., time of 1-24 h, and absolute vacuum of 20-80 kPa.

[0031] Preferably, the activation conditions include: temperature of 100-160° C. and time of 2-6 h.

[0032] Preferably, in step (4), the content of the phase change material in the organic phase change material solution is 5-80 g / L.

[0033] Preferably, the weight ratio of the multi-level porous MOFs material to the organic phase change material is 1:0.05-0.5.

[0034] Preferably, in step (4), the immersion conditions include: time of 4-7 hours and temperature of 40-70°C.

[0035] A third aspect of the present invention provides an application of the multi-level porous MOFs-based composite phase change material in the adsorption of VOCs.

[0036] A fourth aspect of the present invention provides a composition comprising a hierarchical porous MOFs-based composite phase change material and an adsorption material.

[0037] According to a specific embodiment of the present invention, the porous MOFs-based composite phase change material is the porous MOFs-based composite phase change material described in the first aspect of the present invention or the porous MOFs-based composite phase change material prepared by the method described in the second aspect of the present invention.

[0038] According to a specific embodiment of the present invention, the adsorption material is activated carbon or microporous MOFs material.

[0039] According to a specific embodiment of the present invention, the mass ratio of the multi-level porous MOFs-based composite phase change material to the adsorption material is 2-4:1-6.

[0040] According to a specific embodiment of the present invention, the adsorption material is activated carbon;

[0041] Preferably, the mass ratio of the hierarchical MOFs-based composite phase change material to the activated carbon is 3:1, 4:3 or 2:6;

[0042] Preferably, the specific surface area of ​​the activated carbon is 1000-1600m 2 / g; and / or

[0043] The total pore volume of the activated carbon is 0.4-1.0 mL / g; and / or the micropore volume in the total pore volume is 0.2-0.7 mL / g.

[0044] According to a specific embodiment of the present invention, the adsorption material is a microporous MOFs material;

[0045] Preferably, the mass ratio of the multi-level porous MOFs-based composite phase change material to the microporous MOFs material is 3:1, 4:3 or 2:6;

[0046] Preferably, the specific surface area of ​​the microporous MOFs material is 1000-1500m 2 / g; and / or

[0047] The total pore volume of the microporous MOFs material is 0.5-0.8 mL / g; and / or the micropore volume in the total pore volume is 0.4-0.7 mL / g.

[0048] According to a specific embodiment of the present invention, the microporous MOFs material is prepared by the following method:

[0049] a. mixing the second metal salt with water to obtain a second metal salt solution;

[0050] b. mixing a second organic ligand and a second organic solvent to obtain a second organic phase solution;

[0051] c. mixing the second metal salt solution with the second organic phase solution, and then performing a second reaction. After the reaction is completed, solid-liquid separation is performed, and the obtained solid is washed and activated in sequence to obtain a microporous MOFs material;

[0052] Preferably, the second metal salt is selected from one or more of aluminum chloride hexahydrate, copper acetate monohydrate, chromium nitrate nonahydrate, zinc nitrate hexahydrate, zirconium chloride and nickel chloride hexahydrate; and / or

[0053] The content of the second metal salt in the second metal salt solution is 5-50 g / L; and / or

[0054] The second organic ligand is one or more selected from 2-methylterephthalic acid, 2-aminoterephthalic acid, 2-nitroterephthalic acid, 2-sulfonateterephthalic acid, 2,3-dihydroxyterephthalic acid, terephthalic acid, phthalic acid, trimesic acid, 2,5-thiophenedicarboxylic acid and triethylenediamine; and / or

[0055] The second organic solvent is selected from one or more of methanol, ethanol, N,N-dimethylformamide, dichloromethane and 1,2-dichloroethane; and / or

[0056] The content of the second organic ligand in the second organic phase solution is 30-150 g / L; and / or

[0057] The molar ratio of the second metal salt to the second organic ligand is 1:1-2;

[0058] Preferably, the second metal salt is copper acetate monohydrate and / or aluminum chloride hexahydrate; and / or

[0059] The content of the second metal salt in the second metal salt solution is 35-45 g / L; and / or

[0060] The second organic ligand is trimesic acid and / or 2,5-thiophenedicarboxylic acid; and / or

[0061] The second organic solvent is anhydrous ethanol and / or N,N-dimethylformamide; and / or

[0062] The content of the second organic ligand in the second organic phase solution is 32-58 g / L; and / or

[0063] The molar ratio of the second metal salt to the second organic ligand is 1:1.29-1.58;

[0064] Preferably, in step c, the conditions of the second reaction include: temperature of 20-160° C., time of 6-18 h; and / or

[0065] In step c, the activation conditions include: temperature of 80-180° C., time of 1-24 h, and absolute vacuum of 20-80 kPa;

[0066] Preferably, in step c, the conditions of the second reaction include: temperature of 40-100° C., time of 8-9 h; and / or

[0067] In step c, the activation conditions include: temperature of 100-120° C., time of 4-6 hours, and absolute vacuum of 60 kPa.

[0068] A fifth aspect of the present invention provides an adsorption storage device comprising an adsorption storage tank and a first bed layer and a second bed layer filled in the adsorption storage tank;

[0069] The first bed layer is the composition comprising the multi-level porous MOFs-based composite phase change material and activated carbon as described in the fourth aspect of the present invention;

[0070] The second bed layer is the composition comprising the multi-level porous MOFs-based composite phase change material and the microporous MOFs material as described in the fourth aspect of the present invention.

[0071] According to a specific embodiment of the present invention, the mass ratio of the first bed layer to the second bed layer is 1-3:2-7;

[0072] Preferably, the mass ratio of the first bed layer to the second bed layer is 2-3:2-5; and / or

[0073] An air inlet pipe with holes is radially arranged in the adsorption storage tank;

[0074] Preferably, the mass ratio of the first bed layer to the second bed layer is 2:5 or 3:2.

[0075] According to a specific embodiment of the present invention, in the adsorption storage tank, the first bed layer and the second bed layer are sequentially filled from the proximal end to the distal end of the adsorption storage tank inlet.

[0076] According to a specific embodiment of the present invention, in the adsorption storage tank, the first bed layer is a cylinder coaxial with the adsorption storage tank, and the second bed layer is a circular cylinder coaxial with the adsorption storage tank;

[0077] Preferably, in a cross section perpendicular to the axial direction of the adsorption storage tank, the second bed layer wraps the first bed layer in an annular shape.

[0078] The adsorption storage device described herein is filled with a composition comprising the multi-level porous MOF-based composite phase change material and an adsorbent material as a bed layer. This composition effectively absorbs adsorption heat through phase change, reducing the bed temperature and avoiding the generation of high-temperature hot spots in the bed. Furthermore, the adsorption storage device includes only radially arranged air inlet pipes within the adsorption storage tank, without separate heat exchange tubes. This saved space can be used to accommodate more composition, thereby increasing the adsorption capacity of the adsorption storage device. Furthermore, in actual use, the capacity specifications of the adsorption storage tank to be used, and the total filling mass of the first and second beds within the adsorption storage tank, can be determined based on the content of low-molecular hydrocarbons such as methane and ethane in the target associated gas.

[0079] A sixth aspect of the present invention provides an associated gas recovery system, which includes a pressurizing unit, a cooling, condensing and dehumidifying unit and an adsorption storage unit connected in sequence;

[0080] The boosting unit includes a compressor 3 and a gas-liquid separator 5 connected to the compressor, wherein the compressor is used to boost the associated gas to produce compressed condensate and compressed gas, and the gas-liquid separator is used to perform a gas-liquid separation on the compressed condensate and compressed gas;

[0081] The cooling, condensing and dehumidifying unit includes a heat exchanger 7, a condensate discharge line 19 and a condensate tank 9 connected in sequence, wherein the heat exchanger is used to cool, condense and dehumidify the compressed gas to produce dry cooling gas and condensed liquid; the condensate discharge line and the condensate tank are used to perform secondary gas-liquid separation on the dry cooling gas and the condensed liquid;

[0082] The adsorption storage unit includes an adsorption storage device 16 for adsorption storage of the dry cooling gas;

[0083] The adsorption storage device is the adsorption storage device described in the fifth aspect of the present invention.

[0084] In the associated gas recovery system provided by the present invention, the number of the adsorption storage devices can be increased in the adsorption storage unit according to the amount of gas, and each adsorption storage device is connected in parallel.

[0085] According to a specific embodiment of the present invention, the associated gas recovery system further includes a buffer tank 2 provided between the associated gas inlet valve 1 and the compressor 3 .

[0086] During the secondary gas-liquid separation process described herein, a small amount of dry cooling gas will enter the condensate tank along with the condensed liquid. Furthermore, the pressure drop in the condensate tank can cause a small amount of butane and pentane in the condensed liquid to re-convert from liquid to gas, generating volatile gases. To prevent volatile gases from re-entering the associated gas recovery system, an adsorption removal unit is also provided in the associated gas recovery system.

[0087] According to a specific embodiment of the present invention, an adsorption removal unit is provided between the condensate tank 9 and the buffer tank 2; it is used to adsorb and remove the volatile gas in the condensate tank;

[0088] Preferably, the adsorption removal unit includes an adsorption tank 11 connected to the outlet of the condensate tank 9 and a pressure relief line 18 connecting the outlet of the adsorption tank and the inlet of the buffer tank; and / or the pressure relief line further includes a pressure relief valve 12; when the adsorption tank reaches a set pressure, the pressure relief valve can be opened to allow the dry cooling gas to return to the buffer tank along the pressure relief line;

[0089] Preferably, the adsorption tank 11 is filled with activated carbon;

[0090] Preferably, the specific surface area of ​​the activated carbon is 1000-1600m 2 / g; and / or

[0091] The total pore volume of the activated carbon is 0.4-1.0 mL / g; and / or the micropore volume in the total pore volume is 0.2-0.7 mL / g.

[0092] According to a specific embodiment of the present invention, in the boosting unit, a compressor heat exchanger 4 is further connected in parallel between the compressor 3 and the gas-liquid separation tank 5; and / or

[0093] In the cooling, condensing and dehumidifying unit, a valve 8 is provided on the condensate discharge line 19 to limit the dry cooling gas from entering the condensate tank 9; and / or a valve 10 is provided between the outlet of the condensate tank 9 and the inlet of the adsorption tank 11 to prevent the volatile gas entering the adsorption tank from returning to the condensate tank; and / or

[0094] In the adsorption storage unit, a pressure limiting valve 17 is provided at one end of the adsorption storage device 16 away from the inlet. When the pressure in the adsorption storage device exceeds the set pressure of the pressure limiting valve, the pressure is automatically released to avoid danger caused by excessive pressure in the adsorption storage device due to temperature increase.

[0095] and / or

[0096] A valve 15 and a valve 14 are provided in sequence near the inlet of the adsorption storage device 16; and / or

[0097] The valve 14 is used to switch the adsorption storage device; and / or

[0098] The valve 15 is used to manually release the pressure of the adsorption storage device;

[0099] Preferably, a valve 6 is provided between the gas-liquid separator 5 and the heat exchanger 7 to prevent the un-pressurized associated gas from entering the cooling condensation and dehumidification unit in advance; and / or

[0100] A valve 13 is provided between the heat exchanger 7 and the adsorption storage unit to maintain the pressure in the heat exchanger 7.

[0101] The seventh aspect of the present application provides an associated gas recovery process, which comprises the following steps:

[0102] The associated gas recovery system according to the sixth aspect of the present application is provided;

[0103] 1) The associated gas is compressed and heated in the compressor 3 to obtain the compressed gas and compressed condensate, and the compressed condensate is introduced into the gas-liquid separation tank 5 to achieve the primary gas-liquid separation;

[0104] 2) The compressed gas obtained in step 1) is introduced into the heat exchanger 7 to be cooled, condensed and dehumidified to obtain the dry and cooled gas and the condensed liquid, and the condensed liquid is discharged into the condensate tank 9 through the condensate discharge pipeline 19 to achieve the secondary gas-liquid separation;

[0105] 3) The dry and cooled gas obtained in step 2) is introduced into the adsorption storage device 16 for adsorption storage.

[0106] According to one specific embodiment of the present application, in step 1), the pressure of the compressed gas is 2-4 MPa and / or the temperature is 40-70℃; and / or

[0107] In step 2), the temperature of the dry and cooled gas is 0-5℃.

[0108] According to one specific embodiment of the present application, the associated gas is single-lift well associated gas.

[0109] The single-lift well associated gas referred to in the present application refers to the associated gas containing more than 90% VOL of low molecular weight alkanes such as methane and ethane, with the upper limit being 100% VOL, and containing a small amount of propane, butane, pentane and water vapor other than hydrocarbons, generally between 15% RH and 100% RH, and in particular refers to the associated gas with small gas amount (less than 500 m 3 / d), high proportion of low molecular weight alkanes (methane + ethane content of more than 90% VOL), and certain humidity (15% RH to 100% RH).

[0110] Any one of the composition according to the fourth aspect of the present application, the adsorption storage device according to the fifth aspect of the present application, the associated gas recovery system according to the sixth aspect of the present application, and the associated gas recovery process according to the seventh aspect of the present application is applied to the recovery of single-lift well associated gas.

[0111] Utilize the associated gas recovery system described in the sixth aspect of the present invention (such as Figure 12 ), using the associated gas recovery process described in the seventh aspect of the present invention, the process of recovering the associated gas from the single well is as follows:

[0112] Step 1) The associated gas from the single-pull well enters the buffer tank 2 through the inlet valve 1, and the buffer tank is used to regulate the pressure fluctuation of the system to maintain the stability of the system operating conditions; then the associated gas from the single-pull well passes through the buffer tank to the compressor 3 with a set pressure of 2-4 MPa, and is pressurized to 2-4 MPa (absolute pressure) in conjunction with the compression heat exchanger 4. At this time, the temperature of the pressurized associated gas from the single-pull well also rises to 40-70°C, and the water vapor and some macromolecular hydrocarbons therein are converted from gas to liquid due to the pressure increase. The obtained compressed gas and compressed condensate are separated into a gas-liquid state in the gas-liquid separation tank 5 connected to the compressor; in this way, part of the water vapor and part of the macromolecular hydrocarbons including butane, pentane, etc. in the associated gas from the single-pull well are removed, which is beneficial to reduce the influence of water vapor and macromolecular hydrocarbons on the adsorption capacity of low-molecular alkanes such as methane and ethane in the adsorption storage device in the subsequent adsorption storage unit;

[0113] Step 2) When the pressure in the compressor 3 reaches its set value, the valve 6 is opened to allow the compressed gas to enter the heat exchanger 7 with a set pressure of 2-4 MPa. At this point, the valve 13 is always in a closed state; as the compressed gas is filled and the pressure in the heat exchanger 7 reaches its set value, the opening of the valve 13 is adjusted to maintain the pressure in the heat exchanger at about 2-4 MPa; the compressed gas exchanges heat with the refrigerant of the heat exchanger and cools down to a temperature of 0-5°C (for example, about 2°C). During the cooling process, most of the water vapor and a small amount of large molecular hydrocarbons including butane, pentane, etc. in the compressed gas are liquefied to obtain condensed liquid, while low molecular alkanes such as methane and ethane are converted into dry cooling gas. The obtained condensed liquid flows through the condensate discharge line 19 connected to the heat exchanger and enters the condensate tank 9 through the valve 8 (where the condensed liquid is initially cooled). The oil-water separation step completes the secondary gas-liquid separation. During the secondary gas-liquid separation, a small amount of dry cooling gas will enter the condensate tank along with the condensed liquid. In addition, the pressure drop in the condensate tank will cause a small amount of butane and pentane in the condensed liquid to be converted from liquid to gas again, generating volatile gas. The dry cooling gas and the volatile gas enter the adsorption tank 11 filled with activated carbon through the valve 10, wherein the volatile gas is adsorbed and removed by the adsorption tank 11 to avoid entering the associated gas recovery system again. The dry cooling gas flows through the pressure relief pipeline 18 and the pressure relief valve 12 into the buffer tank, and continues to enter the system for recovery along with the single-pull well associated gas that continuously enters the buffer tank at the inlet valve 1. In this way, the influence of water vapor and macromolecular hydrocarbons including butane, pentane, etc. on the adsorption capacity of the adsorption storage device can be further reduced on the basis of step 1).

[0114] Step 3) The dry and cool gas treated by the cooling and dehumidifying unit is introduced into the adsorption storage device 16 through the valve 14 and the manual valve 15 for adsorption storage, and the pressure of the adsorption storage device is set to 2-5 MPa (for example, 4 MPa). When the pressure in the adsorption storage device reaches the set value, the valve 14 is switched to the parallel adsorption storage device. In addition, the pressure limiting valve 17 of each adsorption storage device is set to 6-8 MPa (for example, 6 MPa). When the pressure in the adsorption storage device is higher than the set pressure of the pressure limiting valve 17, the pressure limiting valve 17 is opened to automatically release, so as to avoid the risk of excessive internal pressure caused by the increase of the temperature in the adsorption storage device. When the adsorption storage device reaches the set pressure, the manual valve 15 is closed, and the gas in the adsorption storage device is desorbed and released to the transfer station regularly (for example, every day). First, the manual valve 15 is opened for natural pressure relief. By controlling the opening degree of the manual valve 15, the desorbed gas is slowly introduced into the recovery system of the transfer station, so as to avoid the great impact on the system. Then, vacuum desorption is performed. The vacuum pump is started to suck the adsorption storage device, so that the relative pressure in the device is reduced to -90 to -60 kPa (for example, -90 kPa). After being maintained for 10-60 min (for example, 30 min), the manual valve 15 is closed, and the desorption is completed. The adsorption storage device after the desorption is transported back to the associated gas recovery system to continue the adsorption storage of the dry and cool gas.

[0115] Advantages of the present application:

[0116] To address the limitations of thermal effects on ANG adsorbents and the difficulty in recovering small amounts of scattered associated gas from single wells in the prior art, the present invention provides a composition, an adsorption storage device containing the composition, and an associated gas recovery system. The composition comprises a multi-level porous MOF-based composite phase change material and an adsorbent material, exhibiting phase change temperature control and adsorption storage functions. The multi-level porous MOF-based composite phase change material and the adsorbent material synergistically enhance each other's performance, reducing adsorption temperature rise, weakening the adsorption heat effect, and increasing the composition's adsorption capacity for methane and ethane. The adsorption storage device comprises an adsorption storage tank and the composition, which is filled within the tank as a bed. Because the composition exhibits a low adsorption temperature rise and high adsorption capacity for low-molecular-weight alkanes such as methane and ethane, only radial inlet pipes are provided within the tank, without heat exchange pipes. This conserves internal space within the tank and allows for more composition to be filled. Combined with the design of the bed formulation and filling method within the adsorption storage device, the adsorption storage of low-molecular-weight alkanes such as methane and ethane is achieved with a low adsorption temperature rise and high adsorption capacity. The associated gas recovery system provided by the present invention mainly includes a pressurizing unit, a cooling, condensing and dehumidifying unit and an adsorption storage unit, wherein the adsorption storage unit is the adsorption storage device provided by the present invention. After the associated gas enters the associated gas recovery system, the pressurizing unit generates compressed gas and compressed condensate to achieve primary gas-liquid separation; the cooling, condensing and dehumidifying unit cools, condenses and dehumidifies the compressed gas to obtain dry cooling gas and condensed liquid obtained by condensing water vapor and macromolecular hydrocarbons including butane, pentane, etc., to achieve secondary gas-liquid separation; the adsorption storage device in the adsorption storage unit adsorbs and stores the dry cooling gas. The primary gas-liquid separation removes part of the water vapor and macromolecular hydrocarbons in the associated gas, and the secondary gas-liquid separation further removes most of the water vapor and macromolecular hydrocarbons including butane, pentane, etc. in the associated gas on the basis of the primary gas-liquid separation, thereby avoiding the influence of water vapor and macromolecular hydrocarbons including butane, pentane, etc. on the adsorption capacity of the adsorption storage device for adsorbing low-molecular alkanes such as methane and ethane. The associated gas recovery system provided by the present invention was used to conduct recovery experiments on 100% vol methane and 100% vol ethane at 4 MPa and 2 MPa, respectively: the adsorption capacity for methane was 267-339 mL / g, the maximum temperature during the methane adsorption process was 47-65°C, and the adsorption temperature rise was 22-40°C; the adsorption capacity for ethane was 180-218 mL / g, the maximum temperature during the ethane adsorption process was 44-58°C, and the adsorption temperature rise was 19-33°C.In summary, in combination with the composition provided by the present invention, the adsorption storage device containing the composition, and the associated gas recovery system, a medium pressure-low temperature-phase change temperature control-adsorption storage single-pull well associated gas recovery process can be realized, which can effectively control the adsorption heat, and achieve efficient recovery of single-pull well associated gas with small gas volume, low casing pressure, and long distance from the gathering and transportation station at low cost with lower adsorption temperature rise (not higher than 50°C), higher adsorption capacity (not lower than 180mL / g), and lower pressure (specifically 2-4MPa). BRIEF DESCRIPTION OF THE DRAWINGS

[0117] Figure 1 is the nitrogen adsorption isotherm curve of the microporous MOFs material prepared in Example 1;

[0118] Figure 2 This is the HK (Original) pore size distribution diagram of the microporous MOFs material prepared in Example 1;

[0119] Figure 3 is the NLDFT pore size distribution diagram of the activated carbon used in the present invention;

[0120] Figure 4 is a nitrogen adsorption isotherm curve of the hierarchical MOFs material of Example 3;

[0121] Figure 5 This is the NLDFT pore size distribution diagram of the hierarchical MOFs material of Example 3;

[0122] Figure 6 This is a graph showing the penetration adsorption of ethane by the hierarchical MOFs material of Example 3;

[0123] Figure 7 This is the NLDFT pore size distribution diagram of the hierarchical MOFs-based composite phase change material of Example 3;

[0124] Figure 8 This is a graph showing the penetration adsorption of ethane by the multi-level porous MOFs-based composite phase change material of Example 3;

[0125] Figure 9 This is a graph showing the penetration adsorption of ethane by the multi-level porous MOFs-based composite phase change material of Example 4;

[0126] Figure 10 This is a graph showing the penetration adsorption of ethane by the multi-level porous MOFs-based composite phase change material of Example 5;

[0127] Figure 11Two filling methods for the first and second beds in the adsorption storage device provided by the present invention are shown. In filling method one, within the adsorption storage tank, the first bed is a cylinder coaxial with the adsorption storage tank, and the second bed is a toroidal cylinder coaxial with the adsorption storage tank; in a cross section perpendicular to the axial direction of the adsorption storage tank, the second bed wraps around the first bed in an annular shape; in filling method two, within the adsorption storage tank, the first and second beds are sequentially filled from the proximal end to the distal end of the adsorption storage tank inlet.

[0128] Figure 12 The associated gas recovery system provided by the present invention is shown;

[0129] Figure 13 is a methane adsorption curve diagram of Example 19;

[0130] Figure 14 is the ethane adsorption curve of Example 19;

[0131] Figure 15 is a methane adsorption curve diagram of Example 22;

[0132] Figure 16 This is the ethane adsorption curve of Example 22.

[0133] In this application, Figure 11 、 Figure 12 The accompanying drawings are merely schematic drawings, used only to illustrate the principles of the present invention, and are not drawn to scale. DETAILED DESCRIPTION

[0134] The present invention will be further described below with reference to examples. However, the examples are merely illustrative and do not limit the present invention in any way.

[0135] The first aspect of the present invention provides a multi-level porous MOFs-based composite phase change material, which includes a multi-level porous MOFs material having micropores, mesopores and macropores, and a phase change material loaded in the macropore channels of the multi-level porous MOFs material.

[0136] In the present invention, the multi-level porous MOFs-based composite phase change material comprises a multi-level porous MOFs material and a phase change material. The multi-level porous MOFs material has micropores, mesopores and macropores at the same time, and the phase change material is loaded in the macropore channels of the multi-level porous MOFs material.

[0137] In the present invention, in order to make the hierarchical porous MOFs-based composite phase change material have better adsorption effect and self-temperature control characteristics, it is necessary to reasonably control the proportion of micropores, mesopores and macropores. In a preferred case, the ratio of the micropore volume, mesopore volume and macropore volume of the hierarchical porous MOFs material is 1-4:1-2:1, specifically 1:1:1, 2:1:1, 3:1:1, 4:1:1, 1:2:1, 2:2:1, 3:2:1 or 4:2:1.

[0138] Preferably, the specific surface area of ​​the multi-level porous MOFs material is 600-1700 m 2 / g, specifically 600m 2 / g、700m 2 / g、800m 2 / g、900m 2 / g、1000m 2 / g、1100m 2 / g、1200m 2 / g、1300m 2 / g、1400m 2 / g、1500m 2 / g、1600m 2 / g or 1700m 2 / g.

[0139] In the present invention, in order to ensure that the phase change materials are all loaded in the macropore channels of the multi-level porous MOFs-based composite phase change material, it is preferred that the phase change materials are all macromolecular phase change materials. Further preferably, the phase change materials are selected from one or more of polyols, fatty acids, linear alkanes and paraffins.

[0140] Preferably, the polyols are polyethylene glycol and / or neopentyl glycol.

[0141] Preferably, the fatty acid is selected from one or more of lauric acid, stearic acid, palmitic acid and pentadecanoic acid.

[0142] Preferably, the straight-chain alkane is selected from one or more of n-tetradecane, n-hexadecane and n-octadecane.

[0143] In the present invention, when the phase change material contains paraffin, in order to ensure that the adsorption process can be controlled at a lower temperature, it is more appropriate to select paraffin with a phase change temperature of 30-50°C, and more preferably paraffin with a phase change temperature of 38°C.

[0144] A second aspect of the present invention provides a method for preparing the above-mentioned multi-level porous MOFs-based composite phase change material, the preparation method comprising the following steps:

[0145] (1) mixing a first metal salt with water to obtain a first metal salt solution;

[0146] (2) mixing the template, the first organic ligand, and the first organic solvent to obtain a first organic phase solution;

[0147] (3) mixing the first metal salt solution with the first organic phase solution, and then performing a first reaction. After the reaction is completed, the solid-liquid separation is performed, and the obtained solid is washed and activated in sequence to obtain a hierarchical porous MOFs material;

[0148] (4) Mixing the phase change material with a first organic solvent to obtain an organic phase change material solution, and immersing the multi-level porous MOFs material in the organic phase change material solution.

[0149] In the present invention, the first metal salt is selected from soluble metal salts and / or slightly soluble metal salts.

[0150] Preferably, the first metal salt is selected from aluminum chloride, aluminum chloride hexahydrate, aluminum nitrate, aluminum sulfate, aluminum acetate, ferric chloride, ferric chloride hexahydrate, ferric sulfate, ferric nitrate, ferric acetate, copper chloride, copper sulfate, copper nitrate, copper acetate, copper acetate monohydrate, copper sulfate pentahydrate, copper nitrate trihydrate, chromium nitrate, chromium chloride, chromium sulfate, chromium acetate, chromium nitrate nonahydrate, chromium chloride hexahydrate, zirconium nitrate, zirconium chloride, zirconium sulfate, zirconium acetate, zirconium nitrate pentahydrate, One or more of zinc nitrate, zinc chloride, zinc sulfate, zinc acetate, zinc nitrate hexahydrate, zinc sulfate heptahydrate, nickel nitrate, nickel chloride, nickel sulfate, nickel acetate, nickel sulfate hexahydrate, nickel nitrate hexahydrate, nickel chloride hexahydrate, cobalt nitrate, cobalt chloride, cobalt sulfate, cobalt acetate, cobalt chloride hexahydrate, cobalt nitrate hexahydrate, cobalt sulfate monohydrate, manganese nitrate, manganese chloride, manganese sulfate, manganese acetate, manganese sulfate monohydrate, manganese nitrate hexahydrate, and manganese acetate dihydrate.

[0151] Preferably, the first metal salt is one or more selected from the group consisting of aluminum chloride hexahydrate, copper acetate monohydrate, chromium nitrate nonahydrate, zinc nitrate hexahydrate, zirconium chloride and nickel chloride hexahydrate.

[0152] Preferably, in step (1), the content of the first metal salt in the first metal salt solution is 5-50 g / L, specifically 5 g / L, 10 g / L, 15 g / L, 20 g / L, 25 g / L, 30 g / L, 35 g / L, 40 g / L, 45 g / L or 50 g / L.

[0153] Preferably, the template is selected from one or more of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer (P123), cetyltrimethylammonium bromide (CTAB), sodium dodecylbenzenesulfonate and N,N,N,N-tetramethylethylenediamine.

[0154] Preferably, the first organic ligand is selected from one or more of 2-methylterephthalic acid, 2-aminoterephthalic acid, 2-nitroterephthalic acid, 2-sulfonateterephthalic acid, 2,3-dihydroxyterephthalic acid, terephthalic acid, phthalic acid, trimesic acid, 2,5-thiophenedicarboxylic acid and triethylenediamine.

[0155] More preferably, the first organic ligand is selected from one or more of 2-aminoterephthalic acid, 2,5-thiophenedicarboxylic acid, trimesic acid, terephthalic acid and triethylenediamine.

[0156] Preferably, in step (2), the first organic solvent is selected from one or more of methanol, ethanol, N,N-dimethylformamide (DMF), dichloromethane and 1,2-dichloroethane.

[0157] Preferably, in step (2), the content of the template in the first organic phase solution is 10-80 g / L, and the content of the first organic ligand is 30-150 g / L.

[0158] In a specific embodiment, in step (2), the content of the template in the first organic phase solution can be 10 g / L, 20 g / L, 30 g / L, 40 g / L, 50 g / L, 60 g / L, 70 g / L or 80 g / L, and the content of the first organic ligand in the first organic phase solution can be 30 g / L, 40 g / L, 50 g / L, 60 g / L, 70 g / L, 80 g / L, 90 g / L, 100 g / L, 110 g / L, 120 g / L, 130 g / L, 140 g / L or 150 g / L.

[0159] In the preparation method described in the present invention, under preferred circumstances, the molar ratio of the amount of the first metal salt, the template and the first organic ligand is 1:0.03-1:1-2, wherein the first organic ligand is more than the first metal salt to ensure that after the multi-level porous MOFs material is generated, the unreacted first organic ligand can be washed away with the first organic solvent. Too much template will cause the quality of the multi-level porous MOFs material to be seriously reduced. Therefore, the amount ratio of each raw material needs to be controlled within the above range.

[0160] In a specific embodiment, the molar ratio of the first metal salt, the template and the first organic ligand can be 1:0.03:1, 1:0.04:1, 1:0.05:1, 1:0.06:1, 1:0.07:1, 1:0.08:1, 1:0.09:1, 1:1:1, 1:0.03:2, 1:0.04:2, 1:0.05:2, 1:0.06:2, 1:0.07:2, 1:0.08:2, 1:0.09:2 or 1:1:2.

[0161] In a preferred embodiment of the present invention, in step (3), the conditions of the first reaction include: temperature of 20-160° C., and time of 6-18 h.

[0162] Further preferably, in step (3), the conditions of the first reaction include: temperature of 40-110° C., and time of 8-16 h.

[0163] In a specific embodiment, in step (3), the temperature of the first reaction can be 40°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C or 110°C, and the time of the first reaction can be 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h or 16h.

[0164] In step (3) of the present invention, the obtained solid can be washed with a first organic solvent to remove unreacted first metal salt, template and first organic ligand, etc. The first organic solvent can be selected from one or more of methanol, ethanol, N,N-dimethylformamide, dichloromethane and 1,2-dichloroethane, and preferably anhydrous ethanol is used for washing.

[0165] In step (3) of the present invention, there is no special requirement for the number of washings, and it is sufficient to remove the unreacted first metal salt, template, first organic ligand, etc.

[0166] In a preferred embodiment of the present invention, in step (3), the activation conditions include: temperature of 80-180° C., time of 1-24 h, and absolute vacuum of 20-80 kPa.

[0167] Further preferably, in step (3), the activation temperature is 100-160° C., and the activation time is 2-6 h.

[0168] In specific embodiments, in step (3), the temperature of the activation can be 100°C, 110°C, 120°C, 130°C, 140°C, 150°C or 160°C, the time of the activation can be 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h or 6h, and the absolute vacuum degree of the activation can be 20kPa, 25kPa, 30kPa, 35kPa, 40kPa, 45kPa, 50kPa, 55kPa, 60kPa, 65kPa, 70kPa, 75kPa or 80kPa.

[0169] In preferred embodiments, in step (4), the first organic solvent is selected from one or more of methanol, ethanol, N,N-dimethylformamide, dichloromethane and 1,2-dichloroethane, and is further preferably anhydrous ethanol.

[0170] In step (4) of the present application, in order to ensure that the phase change material is all loaded in the large pore channels of the hierarchical porous MOFs-based composite phase change material, it is preferred that the phase change material is all macromolecular phase change material, and it is further preferred that the phase change material is selected from one or more of polyhydric alcohols, fatty acids, straight-chain alkanes and paraffins.

[0171] Preferably, the polyhydric alcohols are polyethylene glycol and / or neopentyl glycol.

[0172] Preferably, the fatty acids are selected from one or more of lauric acid, stearic acid, palmitic acid and pentadecanoic acid.

[0173] Preferably, the straight-chain alkanes are selected from one or more of n-tetradecane, n-hexadecane and n-octadecane.

[0174] In the present application, when the phase change material contains paraffin, in order to ensure that the adsorption process can be controlled at a lower temperature, it is appropriate to select paraffin with a phase change temperature of 30-50°C, and it is further preferred to select paraffin with a phase change temperature of 38°C.

[0175] In preferred embodiments of the present application, in step (4), the content of the phase change material in the organic phase change material solution is 5-80g / L.

[0176] In specific embodiments, in step (4), the content of the phase change material in the organic phase change material solution can be 5g / L, 15g / L, 25g / L, 35g / L, 45g / L, 55g / L, 65g / L, 75g / L or 80g / L.

[0177] Preferably, in step (4), the weight ratio of the multi-level porous MOFs material to the organic phase change material is 1:0.05-0.5, specifically 1:0.05, 1:0.1, 1:0.15, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45 or 1:0.5.

[0178] In a preferred embodiment of the present invention, in step (4), the immersion conditions include: a time of 4-7 hours and a temperature of 40-70°C.

[0179] In a specific embodiment, in step (4), the immersion time can be 4h, 4.5h, 5h, 5.5h, 6h, 6.5h or 7h, and the immersion temperature can be 40°C, 45°C, 50°C, 55°C, 60°C, 65°C or 70°C.

[0180] In step (4) of the present invention, after the impregnation is completed, filtration is required, and the filtered solid is dried.

[0181] In the present invention, by controlling the dosage ratio of the hierarchical porous MOFs material to the organic phase change material and the impregnation conditions, a suitable hierarchical porous MOFs-based composite phase change material can be obtained.

[0182] In the present invention, the drying conditions include: temperature of 60-70° C. and time of 4-6 hours.

[0183] In a specific embodiment, the drying temperature can be 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C or 70°C, and the drying time can be 4h, 4.5h, 5h, 5.5h or 6h.

[0184] The multi-level porous MOFs-based composite phase change material prepared by the above-mentioned preparation method in the present invention contains 5-30 weight% of phase change material. In a specific embodiment, the content of phase change material in the multi-level porous MOFs-based composite phase change material can be 5 weight%, 10 weight%, 15 weight%, 20 weight%, 25 weight% or 30 weight%.

[0185] A third aspect of the present invention provides an application of the multi-level porous MOFs-based composite phase change material in the adsorption of VOCs.

[0186] In the present invention, under the action of a suitable template, the self-assembly of the first metal salt and the first organic ligand is restricted, the original periodic network structure is destroyed, and the addition amount of the template and the reaction conditions are controlled to obtain a multi-level porous MOFs material having microporous, mesoporous and macroporous structures. The multi-level porous MOFs material has the characteristics of a three-dimensional ordered interconnected structure, an adjustable pore size, an ultra-large specific surface area, etc., and can be used as a carrier of a phase change material. On the basis of the multi-level porous MOFs material, the phase change material is introduced into the macropore channels. Compared with traditional MOFs materials, during the microporous adsorption of VOCs, the mesoporous channels in the multi-level pores facilitate the diffusion of the adsorbate, accelerate the mass transfer rate, and improve the adsorption rate. The phase change material in the macropores offsets the adsorption heat effect through phase change, which can control the temperature rise of the bed, thereby significantly improving the adsorption efficiency of the bed. Therefore, the multi-level porous MOFs material loaded with the phase change material has the function of storing adsorption heat, which can effectively reduce the bed temperature rise during the VOCs adsorption process.

[0187] The multi-level porous MOFs-based composite phase change material provided by the present invention has the following advantages: (1) The present invention adopts the addition of a template to synthesize the multi-level porous MOFs material, and the porous coordination polymer is more evenly and densely distributed on the surface; (2) The synthesis method of the present invention is simple, avoiding cumbersome preparation processes and operating conditions, and is suitable for large-scale preparation and use. The synthesis of the multi-level porous material can be achieved by a one-step method, and the self-controlled temperature adsorption material can be obtained by a simple impregnation method, which has the prospect of large-scale production and application; (3) The multi-level porous MOFs-based composite phase change material prepared by the present invention uses the multi-level porous MOFs material as a matrix, has a high specific surface area and pore volume, and has a certain number of micropores, mesopores and macropores, respectively, and fully develops the functions of pores of different sizes. In the process of microporous adsorption of VOCs, the mesopores are conducive to the mass transfer of the adsorbate and improve the adsorption rate, and the phase change material in the macropores can store adsorption heat to suppress the bed temperature rise.

[0188] The multi-level porous MOFs-based composite phase change material of the present invention has the characteristics of high phase change material loading rate, low bed temperature rise and fast adsorption rate. It can be used in the field of VOCs treatment, especially for adsorbing light hydrocarbons, such as ethane, propane and other small molecules. It has broad application prospects in the adsorption treatment of VOCs and has achieved good technical effects.

[0189] In the following examples, copper acetate monohydrate, triethylenediamine, zinc nitrate hexahydrate and aluminum chloride hexahydrate are all products of Shanghai Aladdin Biochem Technology Co., Ltd., chromium nitrate nonahydrate, zirconium chloride, nickel chloride hexahydrate, trimesic acid, 2,5-thiophene dicarboxylic acid, 2-amino terephthalic acid are all products of Shanghai Maikelin Biochemical Technology Co., Ltd., CTAB is a product of Beijing InoKai Technology Co., Ltd., terephthalic acid is a product of Shanghai Keshu Chemical Technology Co., Ltd., n-octadecane is a product of Tianjin Xinesi Biochemical Technology Co., Ltd., phase change paraffin at 38℃ and 45℃ are products of Shanghai Ruotong New Energy Technology Co., Ltd., anhydrous ethanol and DMF are products of China Pharmaceutical Group Co., Ltd., and activated carbon is a product of Karl Fischer Carbon (Suzhou) Co., Ltd.

[0190] The room temperature in the following examples refers to 25℃.

[0191] Microporous MOFs (metal organic framework) material

[0192] Preparation of microporous MOFs material

[0193] Example 1

[0194] a. 2.8 g of metal salt (copper acetate monohydrate) was added to a beaker containing water, and ultrasonic was performed at room temperature to mix it uniformly to obtain a metal salt solution (the content of metal salt was 35 g / L);

[0195] b. 3.8 g of organic ligand (trimesic acid) was added to a beaker containing organic solvent (anhydrous ethanol), and ultrasonic was performed at room temperature to mix it uniformly to obtain an organic phase solution (the content of organic ligand was 32 g / L);

[0196] c. The metal salt solution obtained in step a and the organic phase solution obtained in step b were added to a reaction bottle together (the molar ratio of the amount of metal salt and organic ligand was 1:1.29), and the reaction bottle was placed in an oil bath pot and reacted at 40℃ for 8 h. After the reaction was completed, a suspension was obtained. After the suspension was cooled to room temperature, centrifugal separation was performed, and the obtained solid was washed with anhydrous ethanol for 2 times. Then, the washed solid was placed in a vacuum oven and activated at 100℃ under an absolute vacuum degree of 60 kPa for 6 h to obtain a MOFs material, which was a microporous MOFs material.

[0197] Example 2

[0198] a. 3.1 g of metal salt (aluminum chloride hexahydrate) was added to a beaker containing water, and ultrasonic was performed at room temperature to mix it uniformly to obtain a metal salt solution (the content of metal salt was 45 g / L);

[0199] b. 3.5 g of an organic ligand (2,5-thiophenedicarboxylic acid) was added to a beaker containing an organic solvent (DMF) and ultrasonically mixed at room temperature to obtain an organic phase solution (the content of the organic ligand was 58 g / L);

[0200] c. The metal salt solution obtained in step a and the organic phase solution obtained in step b are added to a reaction flask (the molar ratio of the metal salt organic ligand is 1:1.58), placed in an oil bath, and reacted at 100°C for 9 hours. After the reaction, a suspension is obtained. After the suspension cools to room temperature, it is centrifuged and the obtained solid is washed twice with anhydrous ethanol. The washed solid is then placed in a vacuum oven and activated at 120°C and an absolute vacuum of 60 kPa for 4 hours to obtain a MOFs material, i.e., a microporous MOFs material.

[0201] Test Example 1

[0202] The nitrogen adsorption isotherms, specific surface areas, total pore volumes, micropore volumes, and pore diameters of the activated carbon used in the present invention and the microporous MOFs materials prepared in Examples 1 and 2 were measured. The activated carbon used in the present invention and the microporous MOFs materials prepared in Example 1 are used as examples for detailed description.

[0203] Testing instrument: BSD-PM2 specific surface area analyzer produced by Beijing Best Instrument Technology Co., Ltd.

[0204] About 100 mg of activated carbon powder sample and microporous MOFs material powder sample prepared in Example 1 were weighed respectively, and after vacuum degassing treatment at 150°C for 12 h, the corresponding data were obtained by testing at liquid nitrogen temperature (-196°C) using nitrogen as a probe molecule.

[0205] The specific surface area (S) of the microporous MOFs material powder sample prepared in Example 1 was calculated according to the Brunauer-Emmet-Teller (BET) equation. BET ), the relative pressure range is 0.01 to 0.15, and the correlation coefficient is required to be greater than 0.999 and the C value is required to be greater than 0. The total pore volume of the microporous MOFs material powder sample prepared in Example 1 is obtained from the N2 adsorption amount when the relative pressure is 0.99. The pore size distribution range and micropore volume of the microporous MOFs material prepared in Example 1 are analyzed by the HK (Original) method: the specific surface area of ​​the microporous MOFs material prepared in Example 1 is 1500m 2 / g; it is a microporous material, and its nitrogen adsorption isotherm is as follows Figure 1 As shown; the pore size distribution is between 0.4 and 0.6 nm (as Figure 2The micropore volume (P / P0=0.123) of the HK (Original) method is about 0.56 mL / g, and the total pore volume (P / P0=0.99, pore diameter <195.6 nm) is 0.74 mL / g.

[0206] The microporous MOFs material prepared in Example 2 was also a microporous material with a specific surface area of ​​1000-1500 m 2 / g, the total pore volume is in the range of 0.5-0.8 mL / g, and the micropore volume is in the range of 0.4-0.7 mL / g.

[0207] The specific surface area (S) of the activated carbon powder sample was calculated according to the Brunauer-Emmet-Teller (BET) equation. BET ), the relative pressure range is 0.01 to 0.25, and the correlation coefficient is required to be greater than 0.999 and the C value is greater than 0. The total pore volume is obtained from the N2 adsorption at a relative pressure of 0.99. The pore size distribution range of activated carbon is calculated using the NLDFT method: the specific surface area of ​​activated carbon reaches 1000m 2 / g or more; it has both micropores and mesopores, with pore sizes mainly distributed between 0.5 and 4 nm (such as Figure 3 As shown in Figure 2, the micropore volume (D≤2nm) according to the NLDFT method is approximately 0.38mL / g, and the total pore volume (D≤43nm) is approximately 0.64mL / g.

[0208] Preparation of hierarchically porous MOFs-based composite phase change materials

[0209] Example 3

[0210] (1) Add 2.8 g of metal salt (copper acetate monohydrate) to a beaker containing water and perform ultrasonication at room temperature to mix the mixture uniformly to obtain a metal salt solution (the content of the metal salt is 35 g / L);

[0211] (2) 3.1 g of the template (CTAB) and 3.8 g of the organic ligand (tricresyl ether) were added to a beaker containing an organic solvent (anhydrous ethanol) and ultrasonicated at room temperature to mix them uniformly to obtain an organic phase solution (the content of the template was 26 g / L and the content of the organic ligand was 32 g / L);

[0212] (3) The metal salt solution obtained in step (1) and the organic phase solution obtained in step (2) were added to a reaction flask (the molar ratio of the metal salt, template and organic ligand was 1:0.61:1.29), placed in an oil bath, and reacted at 40°C for 8 hours. After the reaction, a suspension was obtained. After the suspension cooled to room temperature, it was centrifuged and the obtained solid was washed twice with anhydrous ethanol. The washed solid was then placed in a vacuum oven and activated at 100°C and an absolute vacuum of 40 kPa for 6 hours to obtain a multi-level porous MOFs material B1;

[0213] (4) Add 0.6 g of phase change material (paraffin with a phase change temperature of 38°C) to an organic solvent (anhydrous ethanol), heat and stir at 60°C until completely dissolved to obtain an organic phase change material solution (the content of phase change material is 60 g / L), place 1.5 g of the multi-level porous MOFs material obtained in step (3) in the organic phase change material solution (the weight ratio of the multi-level porous MOFs material to the organic phase change material is 1:0.4), soak at 40°C for 5 hours, and then filter. The obtained solid is dried at 60°C for 4 hours to obtain a multi-level porous MOFs-based composite phase change material A1.

[0214] Example 4

[0215] (1) Add 3.1 g of metal salt (aluminum chloride hexahydrate) to a beaker containing water and perform ultrasonic mixing at room temperature to obtain a metal salt solution (the content of the metal salt is 45 g / L);

[0216] (2) 3.6 g of template (CTAB) and 3.5 g of organic ligand (2,5-thiophenedicarboxylic acid) were added to a beaker containing an organic solvent (DMF) and ultrasonicated at room temperature to mix them uniformly to obtain an organic phase solution (the content of template was 60 g / L and the content of organic ligand was 58 g / L);

[0217] (3) The metal salt solution obtained in step (1) and the organic phase solution obtained in step (2) are added to a reaction flask (the molar ratio of the metal salt, template and organic ligand is 1:0.77:1.58), placed in an oil bath, and reacted at 100° C. for 9 h. After the reaction, a suspension is obtained. After the suspension is cooled to room temperature, it is centrifuged and the obtained solid is washed twice with anhydrous ethanol. The washed solid is then placed in a vacuum oven and activated at 120° C. and an absolute vacuum of 40 kPa for 4 h to obtain a hierarchical MOFs material;

[0218] (4) 0.6 g phase change material (paraffin wax with a phase change temperature of 38°C) was added to an organic solvent (absolute ethanol), heated and stirred at 60°C until completely dissolved to obtain an organic phase change material solution (the content of the phase change material was 60 g / L), 2 g of the hierarchical porous MOFs material obtained in step (3) was placed in the organic phase change material solution (the weight ratio of the hierarchical porous MOFs material to the amount of the organic phase change material was 1:0.3), immersed at 70°C for 5 h, then filtered, and the obtained solid was dried at 60°C for 4 h to obtain a hierarchical porous MOFs-based composite phase change material A2.

[0219] Example 5

[0220] (1) 4 g of a metal salt (chromium nitrate nonahydrate) was added to a beaker containing water, and ultrasonic was performed at room temperature to mix them uniformly to obtain a metal salt solution (the content of the metal salt was 44 g / L);

[0221] (2) 2.6 g of a template agent (CTAB) and 3.4 g of an organic ligand (2-amino terephthalic acid) were added to a beaker containing an organic solvent (absolute ethanol), and ultrasonic was performed at room temperature to mix them uniformly to obtain an organic phase solution (the content of the template agent was 50 g / L, and the content of the organic ligand was 65 g / L);

[0222] (3) The metal salt solution obtained in step (1) and the organic phase solution obtained in step (2) were moved into a reaction kettle (the molar ratio of the metal salt, the template agent and the organic ligand was 1:0.71:1.88), and placed in an oven to react at 90°C for 12 h. After the reaction, a suspension was obtained, and the suspension was centrifuged after it was cooled to room temperature. The obtained solid was washed with absolute ethanol for 2 times, and then the washed solid was placed in a vacuum oven and activated at 120°C under an absolute vacuum degree of 60 kPa for 4 h to obtain a hierarchical porous MOFs material;

[0223] (4) 0.5 g of a phase change material (paraffin wax with a phase change temperature of 38°C) was added to an organic solvent (absolute ethanol), heated and stirred at 60°C until completely dissolved to obtain an organic phase change material solution (the content of the phase change material was 50 g / L), 1.5 g of the hierarchical porous MOFs material obtained in step (3) was placed in the organic phase change material solution (the weight ratio of the hierarchical porous MOFs material to the amount of the organic phase change material was 1:0.33), immersed at 60°C for 5 h, then filtered, and the obtained solid was dried at 60°C for 4 h to obtain a hierarchical porous MOFs-based composite phase change material A3.

[0224] Example 6

[0225] (1) Add 2.5 g of metal salt (zinc nitrate hexahydrate) to a beaker containing water and perform ultrasonication at room temperature to mix the mixture uniformly to obtain a metal salt solution (the content of the metal salt is 30 g / L);

[0226] (2) 2.6 g of template (CTAB) and 1.9 g of organic ligand (terephthalic acid) were added to a beaker containing an organic solvent (DMF) and ultrasonicated at room temperature to mix them uniformly to obtain an organic phase solution (template content: 60 g / L, organic ligand content: 44 g / L);

[0227] (3) The metal salt solution obtained in step (1) and the organic phase solution obtained in step (2) were transferred into a reaction kettle (the molar ratio of the metal salt, template and organic ligand was 1:0.84:1.36), placed in an oven, and reacted at 110° C. for 13 h. After the reaction, a suspension was obtained. After the suspension cooled to room temperature, it was centrifuged and the obtained solid was washed twice with anhydrous ethanol. The washed solid was then placed in a vacuum oven and activated at 140° C. and an absolute vacuum of 60 kPa for 6 h to obtain a multi-level porous MOFs material;

[0228] (4) Add 0.5 g of phase change material (paraffin with a phase change temperature of 38 ° C) to an organic solvent (anhydrous ethanol), heat and stir at 60 ° C until completely dissolved to obtain an organic phase change material solution (the content of phase change material is 50 g / L), place 2 g of the multi-level porous MOFs material obtained in step (3) in the organic phase change material solution (the weight ratio of the multi-level porous MOFs material to the organic phase change material is 1:0.25), soak at 50 ° C for 5 h, and then filter. The obtained solid is dried at 60 ° C for 4 h to obtain a multi-level porous MOFs-based composite phase change material A4.

[0229] Example 7

[0230] (1) Add 1.2 g of metal salt (zirconium chloride) to a beaker containing water and perform ultrasonication at room temperature to mix the mixture evenly to obtain a metal salt solution (the content of the metal salt is 35 g / L);

[0231] (2) 1.6 g of template (CTAB) and 1.1 g of organic ligand (terephthalic acid) were added to a beaker containing an organic solvent (DMF) and ultrasonicated at room temperature to mix them uniformly to obtain an organic phase solution (the content of template was 70 g / L and the content of organic ligand was 48 g / L);

[0232] (3) The metal salt solution obtained in step (1) and the organic phase solution obtained in step (2) were moved into a reaction kettle (the molar ratio of the amounts of the metal salt, the template agent and the organic ligand was 1:0.85:1.29), and were placed in an oven for reaction at 90°C for 12h. After the reaction was completed, a suspension was obtained. After the suspension was cooled to room temperature, centrifugal separation was performed. The obtained solid was washed twice with anhydrous ethanol. Then, the washed solid was placed in a vacuum oven and activated at 120°C under an absolute vacuum degree of 60kPa for 4h. A hierarchical pore MOFs material was obtained.

[0233] (4) 0.3g of a phase change material (paraffin with a phase change temperature of 38°C) was added into an organic solvent (anhydrous ethanol) and heated and stirred at 60°C until completely dissolved, to obtain an organic phase change material solution (the content of the phase change material was 37.5g / L). 3g of the hierarchical pore MOFs material obtained in step (3) was placed in the organic phase change material solution (the weight ratio of the amounts of the hierarchical pore MOFs material and the organic phase change material was 1:0.1). The mixture was immersed at 40°C for 5h, and then filtered. The obtained solid was dried at 60°C for 4h. A hierarchical pore MOFs-based composite phase change material A5 was obtained.

[0234] Example 8

[0235] (1) 0.6g of a metal salt (nickel chloride hexahydrate) was added into a beaker containing water, and was mixed uniformly at room temperature by ultrasonic treatment, to obtain a metal salt solution (the content of the metal salt was 35g / L);

[0236] (2) 0.8g of a template agent (CTAB) and 0.6g of an organic ligand (0.4g of terephthalic acid and 0.2g of triethylenediamine) were added into a beaker containing an organic solvent (DMF), and were mixed uniformly at room temperature by ultrasonic treatment, to obtain an organic phase solution (the content of the template agent was 50g / L, and the content of the organic ligand was 38g / L);

[0237] (3) The metal salt solution obtained in step (1) and the organic phase solution obtained in step (2) were moved into a reaction kettle (the molar ratio of the amounts of the metal salt, the template agent and the organic ligand was 1:0.86:1.66), and were placed in an oven for reaction at 110°C for 16h. After the reaction was completed, a suspension was obtained. After the suspension was cooled to room temperature, centrifugal separation was performed. The obtained solid was washed twice with anhydrous ethanol. Then, the washed solid was placed in a vacuum oven and activated at 120°C under an absolute vacuum degree of 60kPa for 4h. A hierarchical pore MOFs material was obtained.

[0238] (4) Add 0.2 g of phase change material (paraffin with a phase change temperature of 38°C) to an organic solvent (anhydrous ethanol), heat and stir at 60°C until completely dissolved to obtain an organic phase change material solution (the content of phase change material is 40 g / L), place 2 g of the multi-level porous MOFs material obtained in step (3) in the organic phase change material solution (the weight ratio of the multi-level porous MOFs material to the organic phase change material is 1:0.1), immerse at 50°C for 5 hours, and then filter. The obtained solid is dried at 60°C for 4 hours to obtain a multi-level porous MOFs-based composite phase change material A6.

[0239] Example 9

[0240] The method of Example 3 was followed, except that the phase change material used was n-octadecane, to obtain a multi-level porous MOFs-based composite phase change material A7.

[0241] Example 10

[0242] The method of Example 4 was followed, except that the phase change material used was n-octadecane, to obtain a multi-level porous MOFs-based composite phase change material A8.

[0243] Example 11

[0244] The method of Example 5 was followed, except that the phase change material used was n-octadecane, to obtain a multi-level porous MOFs-based composite phase change material A9.

[0245] Example 12

[0246] The method of Example 3 was followed, except that the phase change material used was paraffin with a phase change temperature of 45° C., to obtain a multi-level porous MOFs-based composite phase change material A10.

[0247] Example 13

[0248] The method of Example 4 was followed, except that the phase change material used was paraffin with a phase change temperature of 45° C., to obtain a multi-level porous MOFs-based composite phase change material A11.

[0249] Comparative Example 1

[0250] 0.6 g of phase change material (paraffin with a phase change temperature of 38 ° C) was added to an organic solvent (anhydrous ethanol), heated and stirred at 60 ° C until completely dissolved to obtain an organic phase change material solution (the content of phase change material was 60 g / L), 1.5 g of MOFs material prepared in Example 1 (herein numbered D1-1) was placed in the organic phase change material solution (the weight ratio of MOFs material to organic phase change material was 1:0.4), immersed at 40 ° C for 5 h, and then filtered. The obtained solid was dried at 60 ° C for 4 h to obtain MOFs-based composite phase change material D1-2.

[0251] Comparative Example 2

[0252] 0.6 g of phase change material (n-octadecane) was added to an organic solvent (anhydrous ethanol), heated and stirred at 60 ° C until completely dissolved to obtain an organic phase change material solution (the content of phase change material was 60 g / L), 2 g of MOFs material prepared in Example 2 was placed in the organic phase change material solution (the weight ratio of MOFs material to organic phase change material was 1:0.3), immersed at 70 ° C for 5 h, and then filtered. The obtained solid was dried at 60 ° C for 4 h to obtain MOFs-based composite phase change material D2.

[0253] Test Example 2

[0254] The specific surface area, total pore volume, pore diameter, maximum temperature of the adsorption process, ethane adsorption amount and breakthrough point adsorption rate of A1-A11, B1, D1-1, D1-2 and D2 were measured respectively.

[0255] Testing instrument: BSD-PM2 surface area analyzer produced by Beijing Best Instrument Technology Co., Ltd.

[0256] About 100 mg of powder samples were weighed and vacuum degassed at 150°C for 12 h. The corresponding data were obtained by testing at liquid nitrogen temperature (-196°C) using nitrogen as a probe molecule.

[0257] Among them, the specific surface area (S BET ) was calculated using the Brunauer-Emmet-Teller (BET) equation with a relative pressure range of 0.01 to 0.15, requiring a correlation coefficient greater than 0.999 and a C value greater than 0. The total pore volume was derived from the N2 adsorption at a relative pressure of 0.99. The pore size distribution was obtained using the nonlocalized density functional theory (NLDFT) method.

[0258] The breakthrough adsorption curve of ethane gas for each sample was measured using a multi-component adsorption breakthrough curve analyzer (BSD-MAB) produced by Best Instrument Technology (Beijing) Co., Ltd., and the adsorption amount of ethane was calculated. The highest temperature during the adsorption process was measured by the temperature sensor on the analyzer.

[0259] The specific procedure for determining the ethane breakthrough curve is as follows: First, weigh approximately 150g of sample and load it into the penetration column. Purge the column with helium at a flow rate of 300ml / min for 2 hours to remove impurities on the sample surface. Place the penetration column in a 298K constant-temperature water bath. Once the test environment stabilizes, begin the breakthrough experiment. Measure the ethane breakthrough adsorption curve (gas flow rate of 900ml / min, ethane concentration of 10% VOL, test temperature and pressure of 25°C and 5 bar, respectively) and calculate the adsorption capacity.

[0260] The adsorption amount of each component was calculated using the following formula:

[0261]

[0262] Note: This calculation formula takes into account the concentration change caused by the real-time change of the outlet flow rate due to adsorption, which improves the accuracy of calculating the adsorption amount by concentration integral.

[0263] Q n吸附 : The adsorption capacity of adsorbent on adsorbate n (unit: mL)

[0264] Q n入总 : The total flow rate of adsorbate n flowing into the column within the time ΔT (unit: mL)

[0265] Q n出总 : The total flow rate of adsorbate n flowing out of the column within the time ΔT (unit: mL)

[0266] q 总入 : Total gas flow rate through the column inlet (unit: mL / min)

[0267] q 载气 : Carrier gas flow rate (unit: mL / min)

[0268] C n0 : Percentage concentration of adsorbate n at the inlet of the penetration column (%)

[0269] C nt : The percentage concentration of adsorbate n at a certain moment at the outlet of the penetration column (%)

[0270] ΔT: The total time from the start to the end of adsorption (unit: s) for the adsorption amount of each component.

[0271] The calculation formula of breakthrough point adsorption rate is:

[0272]

[0273] Q: The amount of adsorbate n when the adsorbent is penetrated (unit: mL / g)

[0274] t: time when the adsorbent is penetrated (unit: min)

[0275] The results are shown in Table 1 and Figure 4-10 As shown ( Figure 4 is the nitrogen adsorption isotherm of B1; Figure 5 is the pore size distribution range of B1, Figure 6 This is the breakthrough adsorption curve of B1 for ethane. Figure 7 is the pore size distribution range of A1, Figure 8 is the breakthrough adsorption curve of A1 for ethane, Figure 9 is the breakthrough adsorption curve of A2 for ethane, Figure 10 (This is the breakthrough adsorption curve of A3 for ethane).

[0276] Table 1. Specific surface area, total pore volume, maximum adsorption temperature, ethane adsorption amount, and breakthrough point adsorption rate of A1-A11, B1, D1-1, D1-2, and D2

[0277]

[0278] Figure 4 and Figure 5 The nitrogen adsorption isotherm and pore size distribution of B1 are given. It can be seen from the figure that a multi-level porous MOFs material is generated under the action of the template. Figure 5 As can be seen, B1 possesses a combination of micropores, mesopores, and macropores, with the ratio of micropore volume to mesopore volume to macropore volume being 1.76:1.28:1. Table 1 shows the pore structure data, adsorption temperature rise, and adsorption capacity of the composite materials. Because the phase change material occupies a certain pore volume, the pore volume of A1 is smaller than that of B1 and D1-1. During ethane adsorption, the material absorbs the heat of adsorption due to phase transition, resulting in the lowest temperature rise in A1. Lower temperatures facilitate ethane adsorption, leading to A1's higher ethane adsorption capacity than B1 and D1-1.

[0279] Examples 3-8 demonstrate that this method forms porous MOFs under the action of a template, and can be combined with a phase-change material to form a self-temperature-controlled adsorption material. The resulting materials have pore volumes of 0.3-0.5 mL / g and ethane adsorption capacities of 63-74 mL / g, with a temperature rise of 13-16°C due to ethane adsorption. Materials A7 and A8 demonstrate that composite materials containing n-octadecane can suppress the adsorption temperature rise through the phase change process, but this does have some impact on the pore structure of the adsorption material.

[0280] Comparing Example 3 and Comparative Example 1, material A1 is a multi-level pore MOFs composite with a phase change material, while material D1-2 is a microporous structure, and the phase change material is difficult to enter the micropores, so there is a significant difference in temperature control effect and adsorption performance between the two materials. Since the phase change material is difficult to enter the micropores, the structure and performance of D1-1 and D1-2 are basically similar; for the same reason, the phase change material in Comparative Example 2 is also difficult to enter the micropores, so D2 does not have the function of phase change temperature control, and the ethane adsorption capacity of D2 is low.

[0281] Composition, adsorption storage device and associated gas recovery system

[0282] Multi-level pore MOFs-based composite phase change material or activated carbon or microporous MOFs material used in Examples 14-17 and Comparative Examples 3-5:

[0283] Activated carbon: specific surface area, total pore volume, micropore volume, pore size as shown in Test Example 1.

[0284] Microporous MOFs material: MOFs material prepared in Example 1, specific surface area, total pore volume, micropore volume, pore size as shown in Test Example 1.

[0285] Multi-level pore MOFs-based composite phase change material: porous multi-level MOFs-based composite phase change material A1 prepared in Example 3, specific surface area, total pore volume, pore size, maximum temperature during adsorption process, ethane adsorption capacity, and breakthrough point adsorption rate are shown in Table 1 in Test Example 2.

[0286] It should be noted that in actual use, the capacity specification of the adsorption storage tank used can be determined according to the content of methane, ethane and other low molecular hydrocarbons in the target associated gas, and the total mass of the first bed and the second bed in the adsorption storage tank can be further determined.

[0287] Example 14

[0288] The composition provided in this example:

[0289] Composition A in this example: multi-level pore MOFs-based composite phase change material and activated carbon with a mass ratio of 4:3;

[0290] Composition B in this example: multi-level pore MOFs-based composite phase change material and microporous MOFs material with a mass ratio of 2:6.

[0291] The adsorption storage device provided in this example:

[0292] First bed: Composition A;

[0293] Second bed: Composition B;

[0294] Adsorption storage tank: 50L adsorption tank;

[0295] The filling mass ratio and total filling amount of the first and second bed layers: The first and second bed layers are filled with a total of 15.6 kg in a mass ratio of 2:5;

[0296] Bed filling method in adsorption storage tank: In the adsorption storage tank, Figure 11 In the filling method 1 shown, the first bed layer is a cylinder coaxial with the adsorption storage tank, and the second bed layer is a circular cylinder coaxial with the adsorption storage tank; in the cross section perpendicular to the axis of the adsorption storage tank, the second bed layer wraps the first bed layer in an annular shape to obtain an adsorption storage device.

[0297] The associated gas recovery system provided in this embodiment:

[0298] like Figure 12 As shown, the adsorption storage unit adopts the adsorption storage device provided in this embodiment, and the adsorption tank 11 is filled with activated carbon.

[0299] Example 15

[0300] The composition provided in this embodiment:

[0301] Composition C in this embodiment: a hierarchical MOFs-based composite phase change material and activated carbon in a mass ratio of 3:1;

[0302] Composition D in this embodiment: a hierarchical porous MOFs-based composite phase change material and a microporous MOFs material in a mass ratio of 3:1.

[0303] The adsorption storage device provided in this embodiment:

[0304] First bed: composition C;

[0305] Second bed: composition D;

[0306] Adsorption storage tank: 50L adsorption tank;

[0307] The filling mass ratio and total filling amount of the first and second bed layers: The first and second bed layers are filled with a total of 14.6 kg in a mass ratio of 3:2;

[0308] Bed filling method in adsorption storage tank: In the adsorption storage tank, Figure 11 In the filling method 1 shown, the first bed layer is a cylinder coaxial with the adsorption storage tank, and the second bed layer is a circular cylinder coaxial with the adsorption storage tank; in the cross section perpendicular to the axis of the adsorption storage tank, the second bed layer wraps the first bed layer in an annular shape to obtain an adsorption storage device.

[0309] The associated gas recovery system provided in this embodiment:

[0310] like Figure 12As shown, the adsorption storage unit adopts the adsorption storage device provided in this embodiment, and the adsorption tank 11 is filled with activated carbon.

[0311] Example 16

[0312] The composition provided in this embodiment:

[0313] Composition E in this embodiment: hierarchical MOFs-based composite phase change material and activated carbon in a mass ratio of 2:6;

[0314] Composition F in this embodiment: a hierarchical porous MOFs-based composite phase change material and a microporous MOFs material in a mass ratio of 4:3.

[0315] The adsorption storage device provided in this embodiment:

[0316] First bed: composition E;

[0317] Second bed: composition F;

[0318] Adsorption storage tank: 50L adsorption tank;

[0319] The filling mass ratio and total filling amount of the first and second bed layers: The first and second bed layers are filled with a total of 17 kg in a mass ratio of 3:2;

[0320] Bed filling method in adsorption storage tank: In the adsorption storage tank, Figure 11 In the filling method 1 shown, the first bed layer is a cylinder coaxial with the adsorption storage tank, and the second bed layer is a circular cylinder coaxial with the adsorption storage tank; in the cross section perpendicular to the axis of the adsorption storage tank, the second bed layer wraps the first bed layer in an annular shape to obtain an adsorption storage device.

[0321] The associated gas recovery system provided in this embodiment:

[0322] like Figure 12 As shown, the adsorption storage unit adopts the adsorption storage device provided in this embodiment, and the adsorption tank 11 is filled with activated carbon.

[0323] Example 17

[0324] The composition provided in this embodiment:

[0325] Composition G in this embodiment: hierarchical MOFs-based composite phase change material and activated carbon in a mass ratio of 4:3;

[0326] Composition H in this embodiment: a hierarchical MOFs-based composite phase change material and a microporous MOFs material in a mass ratio of 2:6;

[0327] The adsorption storage device provided in this embodiment:

[0328] First bed: composition G;

[0329] Second bed: composition H;

[0330] Adsorption storage tank: 50L adsorption tank;

[0331] The filling mass ratio and total filling amount of the first and second bed layers: The first and second bed layers are filled with a total of 14 kg in a mass ratio of 2:5;

[0332] Bed filling method in adsorption storage tank: In the adsorption storage tank, Figure 11 In the second filling method shown, the first bed layer and the second bed layer are filled in sequence from the proximal end to the distal end of the adsorption storage tank inlet to obtain an adsorption storage device.

[0333] The associated gas recovery system provided in this embodiment:

[0334] like Figure 12 As shown, the adsorption storage unit adopts the adsorption storage device provided in this embodiment, and the adsorption tank 11 is filled with activated carbon.

[0335] Comparative Example 3

[0336] The adsorption storage device provided in this comparative example:

[0337] Adsorption storage tank: 50L adsorption tank;

[0338] Bed filling method in adsorption storage tank: In the adsorption storage tank, no Figure 11 Filling methods 1 and 2 were used to directly fill 16.4 kg of multi-level porous MOFs-based composite phase change material to obtain an adsorption storage device.

[0339] The associated gas recovery system provided in this comparative example:

[0340] like Figure 12 As shown, the adsorption storage unit adopts the adsorption storage device provided in this comparative example, and the adsorption tank 11 is filled with activated carbon.

[0341] Comparative Example 4

[0342] The adsorption storage device provided in this comparative example:

[0343] Adsorption storage tank: 50L adsorption tank;

[0344] Bed filling method in adsorption storage tank: In the adsorption storage tank, no Figure 11 In filling methods 1 and 2, 15.2 kg of activated carbon is directly filled to obtain an adsorption storage device.

[0345] The associated gas recovery system provided in this comparative example:

[0346] like Figure 12 As shown, the adsorption storage unit adopts the adsorption storage device provided in this comparative example, and the adsorption tank 11 is filled with activated carbon.

[0347] Comparative Example 5

[0348] The adsorption storage device provided in this comparative example:

[0349] Adsorption storage tank: 50L adsorption tank;

[0350] Bed filling method in adsorption storage tank: In the adsorption storage tank, no Figure 11 Using filling methods 1 and 2, 13.6 kg of microporous MOFs material was directly filled to obtain an adsorption storage device.

[0351] The associated gas recovery system provided in this comparative example:

[0352] like Figure 12 As shown, the adsorption storage unit adopts the adsorption storage device provided in this comparative example, and the adsorption tank 11 is filled with activated carbon.

[0353] Utilize the associated gas recovery system provided by any one of Examples 14 to 17 and recover the associated gas of a single-pull well according to the associated gas recovery process provided by the present invention. Here, the process of recovering the associated gas of a single-pull well by implementing the associated gas recovery process provided by the present invention using the associated gas recovery system provided by Example 14 is described in detail as an example.

[0354] Example 18

[0355] The associated gas in the single pull well in this embodiment is a small gas volume (less than 500m 3 / d), associated gas with a high proportion of low molecular weight alkanes (methane + ethane content exceeding 90% VOL), and a certain humidity (15% RH to 100% RH).

[0356] Step 1) The associated gas from the single-pull well enters the buffer tank 2 through the inlet valve 1, and the buffer tank is used to regulate the pressure fluctuation of the system to maintain the stability of the system operating conditions; then the associated gas from the single-pull well passes through the buffer tank to the compressor 3 with a set pressure of 4 MPa, and is pressurized to 4 MPa (absolute pressure) by the compression heat exchanger 4. At this time, the temperature of the pressurized associated gas from the single-pull well also rises to 70°C, and the water vapor and some macromolecular hydrocarbons including butane and pentane therein are converted from gas to liquid due to the pressure increase. The obtained compressed gas and compressed condensate are separated into a gas-liquid state in the gas-liquid separation tank 5 connected to the compressor; in this way, part of the water vapor and macromolecular hydrocarbons in the associated gas from the single-pull well are removed, which is beneficial to reduce the influence of water vapor and macromolecular hydrocarbons on the adsorption capacity of low-molecular alkanes such as methane and ethane in the adsorption storage device in the subsequent adsorption storage unit;

[0357] Step 2) When the pressure in the compressor 3 reaches its set value, the valve 6 is opened to allow the compressed gas to enter the heat exchanger 7 with a set pressure of 4 MPa. At this point, the valve 13 is always in the closed state. As the compressed gas fills and the pressure in the heat exchanger 7 reaches its set value, the opening of the valve 13 is adjusted to maintain the pressure in the heat exchanger at about 4 MPa. The compressed gas exchanges heat with the refrigerant in the heat exchanger and cools down to about 2°C. During the cooling process, most of the water vapor and a small amount of large molecular hydrocarbons including butane and pentane in the compressed gas are liquefied to obtain condensed liquid, while low molecular alkanes such as methane and ethane are converted into dry cooling gas. The obtained condensed liquid flows through the condensate discharge pipeline 19 connected to the heat exchanger and enters the condensate tank 9 through the valve 8 (where the condensed liquid undergoes preliminary oil-water separation). , thus completing the secondary gas-liquid separation; in the secondary gas-liquid separation process, a small amount of dry cooling gas will enter the condensate tank along with the condensed liquid. In addition, the pressure drop in the condensate tank will also cause a small amount of butane and pentane in the condensed liquid to be converted from liquid to gas again to produce volatile gas; the dry cooling gas and the volatile gas enter the adsorption tank 11 filled with activated carbon through the valve 10, wherein the volatile gas is adsorbed and removed by the adsorption tank 11 to avoid entering the associated gas recovery system again, and the dry cooling gas flows through the pressure relief pipeline 18 and the pressure relief valve 12 into the buffer tank, and the single-pull well associated gas that continuously enters the buffer tank at the inlet valve 1 continues to enter the system for recovery. In this way, the influence of water vapor and macromolecular hydrocarbons including butane, pentane, etc. on the adsorption capacity of the adsorption storage device can be further reduced on the basis of step 1);

[0358] Step 3) The dry cooling gas obtained by the cooling and condensing unit enters the adsorption storage device 16 through the valve 14 and the manual valve 15 for adsorption storage. The pressure of the adsorption storage device 16 is set to 4 MPa. When the pressure therein reaches the set value, it is switched to the parallel adsorption storage device through the valve 14. In addition, the pressure of the pressure-limiting valve 17 of each adsorption storage device is set to 6 MPa. When the pressure in the adsorption storage device is higher than the set pressure of the pressure-limiting valve 17, the pressure-limiting valve 17 opens and automatically discharges, thereby avoiding the danger of excessive internal pressure due to the increase in temperature in the adsorption storage device. When the adsorption storage device reaches its set pressure, the manual valve 15 is closed, and the gas is collected to the transfer station regularly (for example, every day) to desorb and release the gas in the adsorption storage device from the device: first, the manual valve 15 is opened for natural pressure relief, and the opening of the manual valve 15 is controlled to allow the desorbed gas to slowly enter the recovery system of the transfer station to avoid excessive impact on the system; then, vacuum desorption is performed, and the vacuum pump is turned on to pump the adsorption storage device to reduce the relative pressure in the device to -90kPa. After maintaining for 30 minutes, the manual valve 15 is closed, and the desorption is completed; the adsorption storage device after desorption is transported back to the associated gas recovery system to continue the adsorption storage of dry cooling gas.

[0359] Recovery of methane and ethane using a system and process for recovering associated gas

[0360] In order to facilitate indoor experimental evaluation, the capacity of the adsorption storage device in the associated gas recovery system provided in Examples 14-17 and Comparative Examples 3-5 for recovering methane and ethane in Examples 19-22 and Comparative Example 6-8 was adjusted to a laboratory level (specifically, all were adjusted to 250 mL adsorption tanks, and the total amount of the bed filled in the adsorption storage tank was reduced to 2% by weight of the original total amount of filling); in addition, a temperature probe (for example, a PT110 temperature probe) was arranged in the above-mentioned 250 mL adsorption tank, and the maximum temperature of the adsorption storage device during the adsorption of methane and ethane was determined during the recovery of methane and ethane in Examples 19-22 and Comparative Example 6-8.

[0361] The adsorption capacity of methane and ethane in Examples 19-22 and Comparative Example 6-8 was obtained by dividing the total amount of methane or ethane gas flowing through the inlet valve 1 of the associated gas recovery system by the total mass of the bed filled in the adsorption storage tank, and the specific calculation formula was as follows:

[0362]

[0363] wherein Q n : the adsorption amount of the adsorbate n recovered by the associated gas recovery system, in mL / g;

[0364] q n : the flow rate of the adsorbate n, in mL / min;

[0365] t: the time required for the adsorption storage tank to reach the set pressure, in min;

[0366] m: the total mass of the bed filled in the adsorption storage tank, in g.

[0367] Example 19

[0368] Recovery of methane using the associated gas recovery system provided in Example 14:

[0369] 100% VOL methane enters the buffer tank 2 through the inlet valve 1 at a flow rate of 1200 mL / min. The buffer tank is used to regulate the pressure fluctuation of the system to maintain the stable operating conditions of the system. The methane gas then passes through the buffer tank to the compressor 3 with a set pressure of 4 MPa. The methane gas is pressurized to 4 MPa (absolute pressure) by the compression heat exchanger 4. At this time, the temperature of the pressurized methane gas also rises to about 70°C. When the pressure in the compressor reaches the set value (i.e., 4 MPa), the valve 6 is opened to allow the compressed methane gas to enter the heat exchanger 7 with a set pressure of 4 MPa. At this point, valve 13 is always in a closed state; as the compressed methane gas fills up and the pressure in the heat exchanger 7 reaches the set value (i.e., 4 MPa), the opening of valve 13 is adjusted to maintain the pressure in the heat exchanger at around 4 MPa; the compressed methane gas is cooled down to around 2°C by heat exchange with the refrigerant in the heat exchanger and is converted into cooled and dry methane gas, which enters the adsorption storage device 16 through valve 14 and manual valve 15 for adsorption storage. After 22 minutes, the adsorption storage device 16 reaches its set pressure of 4 MPa, and valve 14 and manual valve 15 are cut off.

[0370] During the methane adsorption process, the adsorption curve of the adsorption storage device for methane and the maximum temperature of the bed in the adsorption storage device during the adsorption process were measured. The specific results are shown in Figure 13 , Table 2.

[0371] Ethane is recovered using the associated gas recovery system provided in Example 14:

[0372] 100% VOL ethane enters the buffer tank 2 through the inlet valve 1 at a flow rate of 1200 mL / min. The buffer tank is used to regulate the pressure fluctuation of the system to maintain the stability of the system operating conditions. The ethane gas then passes through the buffer tank to the compressor 3 with a set pressure of 2 MPa. The ethane gas is boosted to 2 MPa (absolute pressure) by the compression heat exchanger 4. At this time, the temperature of the boosted ethane gas also rises to about 40°C. When the pressure in the compressor reaches the set value (i.e., 2 MPa), the valve 6 is opened to allow the compressed ethane gas to enter the heat exchanger 7 with a set pressure of 2 MPa. , so far the valve 13 is always in the closed state; as the compressed ethane gas fills up and the pressure in the heat exchanger 7 reaches the set value (i.e. 2 MPa), the opening of the valve 13 is adjusted to maintain the pressure in the heat exchanger at about 2 MPa; the compressed ethane gas is cooled by heat exchange with the refrigerant of the heat exchanger and its temperature is reduced to about 2°C, and is converted into cooled and dry ethane gas, which enters the adsorption storage device 16 through the valve 14 and the manual valve 15 for adsorption storage. After 14.2 minutes, the adsorption storage device 16 reaches its set pressure of 2 MPa, and the valve 14 and the manual valve 15 are cut off.

[0373] During the ethane adsorption process, the adsorption capacity of the adsorption storage device for ethane and the maximum temperature of the bed in the adsorption storage device during the adsorption process were measured. The specific results are shown in Figure 14 , Table 2.

[0374] Example 20

[0375] Methane is recovered using the associated gas recovery system provided in Example 15:

[0376] 100% VOL methane enters the buffer tank 2 through the inlet valve 1 at a flow rate of 1200 mL / min. The buffer tank is used to regulate the pressure fluctuation of the system to maintain the stable working condition of the system. The methane gas then passes through the buffer tank to the compressor 3 with a set pressure of 4 MPa. The methane gas is pressurized to 4 MPa (absolute pressure) by the compression heat exchanger 4. At this time, the temperature of the pressurized methane gas also rises to about 70°C. When the pressure in the compressor reaches the set value (i.e. 4 MPa), the valve 6 is opened to allow the compressed methane gas to enter the heat exchanger 7 with a set pressure of 4 MPa. , so far the valve 13 is always in the closed state; as the compressed methane gas fills up and the pressure in the heat exchanger 7 reaches the set value (i.e. 4 MPa), the opening of the valve 13 is adjusted to maintain the pressure in the heat exchanger at about 4 MPa; the compressed methane gas is cooled by heat exchange with the refrigerant of the heat exchanger and its temperature is reduced to about 2°C, and is converted into cooled and dry methane gas, which enters the adsorption storage device 16 through the valve 14 and the manual valve 15 for adsorption storage. After 16.6 minutes, the adsorption storage device 16 reaches its set pressure of 4 MPa, and the valve 14 and the manual valve 15 are cut off.

[0377] During the methane adsorption process, the adsorption capacity of the adsorption storage device for methane and the maximum temperature of the bed in the adsorption storage device during the adsorption process were measured. The specific results are shown in Table 2.

[0378] Ethane is recovered using the associated gas recovery system provided in Example 15:

[0379] 100% VOL ethane enters the buffer tank 2 through the inlet valve 1 at a flow rate of 1200 mL / min, and the buffer tank is used to regulate the pressure fluctuation of the system to maintain stable system operation. Then the ethane gas enters the compressor 3 with a set pressure of 2 MPa through the buffer tank, and the compressed heat exchanger 4 is used to increase the pressure of the ethane gas to 2 MPa (absolute pressure). At this time, the temperature of the pressurized ethane gas also rises to about 40°C. When the pressure in the compressor reaches the set value (i.e. 2 MPa), the valve 6 is opened, and the compressed ethane gas enters the heat exchanger 7 with a set pressure of 2 MPa. At this time, the valve 13 is always closed. When the compressed ethane gas fills the heat exchanger 7 and the pressure in the heat exchanger 7 reaches the set value (i.e. 2 MPa), the opening of the valve 13 is adjusted to maintain the pressure in the heat exchanger at about 2 MPa. After the compressed ethane gas is cooled by heat exchange with the coolant in the heat exchanger, the temperature of the ethane gas is reduced to about 2°C, and the ethane gas is converted into cooled and dried ethane gas. The cooled and dried ethane gas enters the adsorption storage device 16 through the valve 14 and the manual valve 15 for adsorption storage. After 11.2 min, the adsorption storage device 16 reaches the set pressure of 2 MPa, and the valve 14 and the manual valve 15 are cut off.

[0380] During the adsorption of ethane, the adsorption capacity of the adsorption storage device for ethane and the maximum temperature of the bed in the adsorption storage device during the adsorption process are measured. The specific results are shown in Table 2.

[0381] Example 21

[0382] The associated gas recovery system provided in Example 16 is used to recover methane:

[0383] 100% VOL methane enters the buffer tank 2 through the inlet valve 1 at a flow rate of 1200 mL / min, and the buffer tank is used to regulate the pressure fluctuation of the system to maintain stable system operation. Then the methane gas enters the compressor 3 with a set pressure of 4 MPa through the buffer tank, and the compressed heat exchanger 4 is used to increase the pressure of the methane gas to 4 MPa (absolute pressure). At this time, the temperature of the pressurized methane gas also rises to about 70°C. When the pressure in the compressor reaches the set value (i.e. 4 MPa), the valve 6 is opened, and the compressed methane gas enters the heat exchanger 7 with a set pressure of 4 MPa. At this time, the valve 13 is always closed. When the compressed methane gas fills the heat exchanger 7 and the pressure in the heat exchanger 7 reaches the set value (i.e. 4 MPa), the opening of the valve 13 is adjusted to maintain the pressure in the heat exchanger at about 4 MPa. After the compressed methane gas is cooled by heat exchange with the coolant in the heat exchanger, the temperature of the methane gas is reduced to about 2°C, and the methane gas is converted into cooled and dried methane gas. The cooled and dried methane gas enters the adsorption storage device 16 through the valve 14 and the manual valve 15 for adsorption storage. After 22.1 min, the adsorption storage device 16 reaches the set pressure of 4 MPa, and the valve 14 and the manual valve 15 are cut off.

[0384] During the methane adsorption process, the adsorption capacity of the adsorption storage device for methane and the maximum temperature of the bed in the adsorption storage device during the adsorption process were measured. The specific results are shown in Table 2.

[0385] Ethane is recovered using the associated gas recovery system provided in Example 16:

[0386] 100% VOL ethane enters the buffer tank 2 through the inlet valve 1 at a flow rate of 1200 mL / min. The buffer tank is used to regulate the pressure fluctuation of the system to maintain the stability of the system operating conditions. The ethane gas then passes through the buffer tank to the compressor 3 with a set pressure of 2 MPa. The ethane gas is boosted to 2 MPa (absolute pressure) by the compression heat exchanger 4. At this time, the temperature of the boosted ethane gas also rises to about 40°C. When the pressure in the compressor reaches the set value (i.e., 2 MPa), the valve 6 is opened to allow the compressed ethane gas to enter the heat exchanger 7 with a set pressure of 2 MPa. , so far the valve 13 is always in the closed state; as the compressed ethane gas fills up and the pressure in the heat exchanger 7 reaches the set value (i.e., 2 MPa), the opening of the valve 13 is adjusted to maintain the pressure in the heat exchanger at about 2 MPa; the compressed ethane gas is cooled by heat exchange with the refrigerant of the heat exchanger and its temperature is reduced to about 2°C, and is converted into cooled and dry ethane gas, which enters the adsorption storage device 16 through the valve 14 and the manual valve 15 for adsorption storage. After 13.6 minutes, the adsorption storage device 16 reaches its set pressure of 2 MPa, and the valve 14 and the manual valve 15 are cut off.

[0387] During the ethane adsorption process, the ethane adsorption capacity of the adsorption storage device and the maximum temperature of the bed in the adsorption storage device during the adsorption process were measured. The specific results are shown in Table 2.

[0388] Example 22

[0389] Methane is recovered using the associated gas recovery system provided in Example 17:

[0390] 100% VOL methane enters the buffer tank 2 through the inlet valve 1 at a flow rate of 1200 mL / min. The buffer tank is used to regulate the pressure fluctuation of the system to maintain the stable working condition of the system. The methane gas then passes through the buffer tank to the compressor 3 with a set pressure of 4 MPa. The methane gas is pressurized to 4 MPa (absolute pressure) by the compression heat exchanger 4. At this time, the temperature of the pressurized methane gas also rises to about 70°C. When the pressure in the compressor reaches the set value (i.e. 4 MPa), the valve 6 is opened to allow the compressed methane gas to enter the heat exchanger 7 with a set pressure of 4 MPa. , so far the valve 13 is always in the closed state; as the compressed methane gas fills up and the pressure in the heat exchanger 7 reaches the set value (i.e. 4 MPa), the opening of the valve 13 is adjusted to maintain the pressure in the heat exchanger at about 4 MPa; the compressed methane gas is cooled by heat exchange with the refrigerant of the heat exchanger and its temperature is reduced to about 2°C, and is converted into cooled and dry methane gas, which enters the adsorption storage device 16 through the valve 14 and the manual valve 15 for adsorption storage. After 15.6 minutes, the adsorption storage device 16 reaches its set pressure of 4 MPa, and the valve 14 and the manual valve 15 are cut off.

[0391] During the methane adsorption process, the adsorption capacity of the adsorption storage device for methane and the maximum temperature of the bed in the adsorption storage device during the adsorption process were measured. The specific results are shown in Figure 15 , Table 2.

[0392] Ethane is recovered using the associated gas recovery system provided in Example 17:

[0393] 100% VOL ethane enters the buffer tank 2 through the inlet valve 1 at a flow rate of 1200 mL / min. The buffer tank is used to regulate the pressure fluctuation of the system to maintain the stability of the system operating conditions. The ethane gas then passes through the buffer tank to the compressor 3 with a set pressure of 2 MPa. The ethane gas is boosted to 2 MPa (absolute pressure) by the compression heat exchanger 4. At this time, the temperature of the boosted ethane gas also rises to about 40°C. When the pressure in the compressor reaches the set value (i.e., 2 MPa), the valve 6 is opened to allow the compressed ethane gas to enter the heat exchanger 7 with a set pressure of 2 MPa. , so far the valve 13 is always in the closed state; as the compressed ethane gas fills up and the pressure in the heat exchanger 7 reaches the set value (i.e. 2 MPa), the opening of the valve 13 is adjusted to maintain the pressure in the heat exchanger at about 2 MPa; the compressed ethane gas is cooled by heat exchange with the refrigerant of the heat exchanger and its temperature is reduced to about 2°C, and is converted into cooled and dry ethane gas, which enters the adsorption storage device 16 through the valve 14 and the manual valve 15 for adsorption storage. After 14.2 minutes, the adsorption storage device 16 reaches its set pressure of 2 MPa, and the valve 14 and the manual valve 15 are cut off.

[0394] In the adsorption process of ethane, the adsorption capacity of the adsorption storage device for ethane and the highest temperature of the bed in the adsorption storage device during the adsorption process were determined, and the specific results are shown in Table 2. Figure 16

[0395] Comparative Example 6

[0396] The methane was recovered by using the associated gas recovery system provided in Comparative Example 3:

[0397] 100% VOL methane entered the buffer tank 2 through the inlet valve 1 at a flow rate of 1200 mL / min, and the buffer tank was used to adjust the pressure fluctuation of the system to maintain the stability of the system operation. Then the methane gas passed through the buffer tank to the compressor 3 with a set pressure of 4 MPa, and the methane gas was pressurized to 4 MPa (absolute pressure) by cooperating with the compression heat exchanger 4. At this time, the temperature of the pressurized methane gas also increased to about 70°C. When the pressure in the compressor reached the set value (i.e. 4 MPa), the valve 6 was opened, and the compressed methane gas entered the heat exchanger 7 with a set pressure of 4 MPa. At this time, the valve 13 was always closed. When the compressed methane gas filled the heat exchanger 7 and the pressure in the heat exchanger 7 reached the set value (i.e. 4 MPa), the opening of the valve 13 was adjusted to maintain the pressure in the heat exchanger at about 4 MPa. After the compressed methane gas was cooled and dried by heat exchange with the coolant in the heat exchanger, the temperature of the cooled and dried methane gas was reduced to about 2°C, and the cooled and dried methane gas entered the adsorption storage device 16 for adsorption storage through the valve 14 and the hand valve 15. After 12.9 min, the adsorption storage device 16 reached the set pressure of 4 MPa, and the valve 14 and the hand valve 15 were cut off.

[0398] In the adsorption process of methane, the adsorption capacity of the adsorption storage device for methane and the highest temperature of the bed in the adsorption storage device during the adsorption process were determined, and the specific results are shown in Table 2.

[0399] The ethane was recovered by using the associated gas recovery system provided in Comparative Example 3:

[0400] ​100% VOL ethane enters buffer tank 2 through inlet valve 1 at a flow rate of 1200 mL / min. The buffer tank is used to regulate system pressure fluctuations and maintain system operating stability. The ethane gas then passes through the buffer tank to compressor 3 with a set pressure of 2 MPa. The ethane gas is then pressurized to 2 MPa (absolute pressure) by the compression heat exchanger 4. The temperature of the pressurized ethane gas also rises to about 40°C. When the pressure in the compressor reaches the set value (i.e., 2 MPa), valve 6 is opened to allow the compressed ethane gas to enter heat exchanger 7 with a set pressure of 2 MPa. At this point, valve 13 is always in a closed state; as the compressed ethane gas fills up and the pressure in the heat exchanger 7 reaches the set value (i.e., 2 MPa), the opening of valve 13 is adjusted to maintain the pressure in the heat exchanger at around 2 MPa; the compressed ethane gas is cooled down to around 2°C by heat exchange with the refrigerant in the heat exchanger and converted into cooled and dry ethane gas, which enters the adsorption storage device 16 through valve 14 and manual valve 15 for adsorption storage. After 9.7 minutes, the adsorption storage device 16 reaches its set pressure of 2 MPa, and valve 14 and manual valve 15 are cut off.

[0401] During the ethane adsorption process, the ethane adsorption capacity of the adsorption storage device and the maximum temperature of the bed in the adsorption storage device during the adsorption process were measured. The specific results are shown in Table 2.

[0402] Comparative Example 7

[0403] Methane is recovered using the associated gas recovery system provided in Comparative Example 4:

[0404] 100% VOL methane enters the buffer tank 2 through the inlet valve 1 at a flow rate of 1200 mL / min. The buffer tank is used to regulate the pressure fluctuation of the system to maintain the stable working condition of the system. The methane gas then passes through the buffer tank to the compressor 3 with a set pressure of 4 MPa. The methane gas is pressurized to 4 MPa (absolute pressure) by the compression heat exchanger 4. At this time, the temperature of the pressurized methane gas also rises to about 70°C. When the pressure in the compressor reaches the set value (i.e. 4 MPa), the valve 6 is opened to allow the compressed methane gas to enter the heat exchanger 7 with a set pressure of 4 MPa. , so far the valve 13 is always in the closed state; as the compressed methane gas fills up and the pressure in the heat exchanger 7 reaches the set value (i.e. 4 MPa), the opening of the valve 13 is adjusted to maintain the pressure in the heat exchanger at about 4 MPa; the compressed methane gas is cooled by heat exchange with the refrigerant of the heat exchanger and its temperature is reduced to about 2°C, and is converted into cooled and dry methane gas, which enters the adsorption storage device 16 through the valve 14 and the manual valve 15 for adsorption storage. After 10.7 minutes, the adsorption storage device 16 reaches its set pressure of 4 MPa, and the valve 14 and the manual valve 15 are cut off.

[0405] During the methane adsorption process, the adsorption capacity of the adsorption storage device for methane and the maximum temperature of the bed in the adsorption storage device during the adsorption process were measured. The specific results are shown in Table 2.

[0406] Ethane is recovered using the associated gas recovery system provided in Comparative Example 4:

[0407] 100% VOL ethane enters buffer tank 2 through inlet valve 1 at a flow rate of 1200 mL / min. The buffer tank is used to regulate system pressure fluctuations and maintain system operating stability. The ethane gas then passes through the buffer tank to compressor 3 with a set pressure of 2 MPa. The ethane gas is then pressurized to 2 MPa (absolute pressure) by the compression heat exchanger 4. The temperature of the pressurized ethane gas also rises to about 40°C. When the pressure in the compressor reaches the set value (i.e., 2 MPa), valve 6 is opened to allow the compressed ethane gas to enter heat exchanger 7 with a set pressure of 2 MPa. At this point, valve 13 is always in a closed state; as the compressed ethane gas fills up and the pressure in the heat exchanger 7 reaches the set value (i.e., 2 MPa), the opening of valve 13 is adjusted to maintain the pressure in the heat exchanger at around 2 MPa; the compressed ethane gas is cooled down to around 2°C by heat exchange with the refrigerant in the heat exchanger and converted into cooled and dry ethane gas, which enters the adsorption storage device 16 through valve 14 and manual valve 15 for adsorption storage. After 8.8 minutes, the adsorption storage device 16 reaches its set pressure of 2 MPa, and valve 14 and manual valve 15 are cut off.

[0408] During the ethane adsorption process, the ethane adsorption capacity of the adsorption storage device and the maximum temperature of the bed in the adsorption storage device during the adsorption process were measured. The specific results are shown in Table 2.

[0409] Comparative Example 8

[0410] Methane is recovered using the associated gas recovery system provided in Comparative Example 5:

[0411] 100% VOL methane enters the buffer tank 2 through the inlet valve 1 at a flow rate of 1200 mL / min, and the buffer tank is used to regulate the pressure fluctuation of the system to maintain stable system operation. Then the methane gas enters the compressor 3 at a set pressure of 4 MPa through the buffer tank, and the compressed heat exchanger 4 is used to increase the pressure of the methane gas to 4 MPa (absolute pressure). At this time, the temperature of the pressurized methane gas also rises to about 70°C. When the pressure in the compressor reaches the set value (i.e., 4 MPa), the valve 6 is opened, and the compressed methane gas enters the heat exchanger 7 at a set pressure of 4 MPa. At this time, the valve 13 is always closed. When the compressed methane gas fills the heat exchanger 7 and the pressure in the heat exchanger 7 reaches the set value (i.e., 4 MPa), the opening of the valve 13 is adjusted to maintain the pressure in the heat exchanger at about 4 MPa. After the compressed methane gas is cooled and heated with the coolant in the heat exchanger, the temperature of the compressed methane gas is reduced to about 2°C, and the cooled and dried methane gas enters the adsorption storage device 16 through the valve 14 and the manual valve 15 for adsorption storage. After 13.2 min, the adsorption storage device 16 reaches the set pressure of 4 MPa, and the valve 14 and the manual valve 15 are cut off.

[0412] During the adsorption of methane, the adsorption capacity of the adsorption storage device for methane and the maximum temperature of the bed in the adsorption storage device during the adsorption process are measured. The specific results are shown in Table 2.

[0413] The associated gas recovery system provided in Comparative Example 5 is used to recover ethane:

[0414] 100% VOL methane enters the buffer tank 2 through the inlet valve 1 at a flow rate of 1200 mL / min, and the buffer tank is used to regulate the pressure fluctuation of the system to maintain stable system operation. Then the methane gas enters the compressor 3 at a set pressure of 4 MPa through the buffer tank, and the compressed heat exchanger 4 is used to increase the pressure of the methane gas to 4 MPa (absolute pressure). At this time, the temperature of the pressurized methane gas also rises to about 70°C. When the pressure in the compressor reaches the set value (i.e., 4 MPa), the valve 6 is opened, and the compressed methane gas enters the heat exchanger 7 at a set pressure of 4 MPa. At this time, the valve 13 is always closed. When the compressed methane gas fills the heat exchanger 7 and the pressure in the heat exchanger 7 reaches the set value (i.e., 4 MPa), the opening of the valve 13 is adjusted to maintain the pressure in the heat exchanger at about 4 MPa. After the compressed methane gas is cooled and heated with the coolant in the heat exchanger, the temperature of the compressed methane gas is reduced to about 2°C, and the cooled and dried methane gas enters the adsorption storage device 16 through the valve 14 and the manual valve 15 for adsorption storage. After 13.2 min, the adsorption storage device 16 reaches the set pressure of 4 MPa, and the valve 14 and the manual valve 15 are cut off.

[0415] The adsorption capacity of the adsorption storage device for ethane and the maximum temperature of the bed in the adsorption storage device during the adsorption process were determined, and the specific results are shown in Table 2.

[0416] Evaluation of methane and ethane adsorption results

[0417] Figure 13 、 15 The methane adsorption curves of Examples 19 and 22, in turn; Figure 14 、 16 The ethane adsorption curves of Examples 19 and 22, in turn. The methane and ethane adsorption capacities of Examples 19-22 and Comparative Examples 6-8 and the maximum bed temperature during the methane and ethane adsorption process are shown in Table 2.

[0418] Table 2. Methane and ethane adsorption capacities and maximum bed temperature of the adsorption storage device during the adsorption process

[0419]

[0420] In combination Figures 13 to 16As can be seen from the data in Table 2, Examples 19 to 22 sequentially use the associated gas recovery systems provided by Examples 14 to 17 (the adsorption storage devices therein are all filled with the composition) for the adsorption effect of methane and ethane, as well as the temperature control effect during the adsorption process. The adsorption capacity for methane is 267-339 mL / g, the maximum temperature of the adsorption storage device during the methane adsorption process is 47-65°C, and the corresponding adsorption temperature rise is 22-40°C; the adsorption capacity for ethane is 180-218 mL / g, the maximum temperature of the adsorption storage device during the ethane adsorption process is 44-58°C, and the corresponding adsorption temperature rise is 19-33°C. Comparative Examples 6, 7, and 8 use the associated gas recovery systems provided in Comparative Examples 3, 4, and 5, respectively (the adsorption storage devices therein are respectively filled with only multi-level pore MOFs-based composite phase change materials, activated carbon, and microporous MOFs materials), which cannot simultaneously achieve higher methane and ethane adsorption capacities and better temperature control effects during the adsorption process: Comparative Example 6 uses the associated gas recovery system provided in Comparative Example 3 (the adsorption storage device therein is only filled with multi-level pore MOFs-based composite phase change materials), which has a better temperature control effect during the adsorption of methane and ethane, with the highest temperatures being only 41°C and 39°C, respectively, and the corresponding adsorption temperature rises being 16°C and 14°C, respectively, but its adsorption capacities for methane and ethane are significantly lower, specifically 189mL / g and 142mL / g, respectively; Comparative Example 7 uses the associated gas recovery system provided in Comparative Example 3, which has a better temperature control effect during the adsorption of methane and ethane, with the highest temperatures being only 41°C and 39°C, respectively, and the corresponding adsorption temperature rises being 16°C and 14°C, respectively. However, its adsorption capacities for methane and ethane are significantly lower, specifically 189mL / g and 142mL / g, respectively. The associated gas recovery system provided in Comparative Example 4 (in which the adsorption storage device is only filled with activated carbon) has the worst temperature control effect during the adsorption process of methane and ethane, with the highest temperatures reaching 71°C and 69°C, respectively, and the corresponding adsorption temperature rises being 46°C and 44°C. Moreover, its adsorption capacity for methane and ethane is also relatively low, with the adsorption capacities being 169mL / g and 139mL / g, respectively. Comparative Example 8 uses the associated gas recovery system provided in Comparative Example 5 (in which the adsorption storage device is only filled with microporous MOFs material). The temperature control effect during the adsorption process of methane and ethane is relatively poor, with the highest temperatures being 67°C and 64°C, respectively, and the corresponding adsorption temperature rises being 42°C and 39°C. Its adsorption capacity for methane and ethane is relatively low, with the adsorption capacities being 233mL / g and 162mL / g, respectively. The above data show that in the composition filled in the adsorption storage device provided by the present invention, the multi-level porous MOFs-based composite phase change material and activated carbon, the multi-level porous MOFs-based composite phase change material and microporous MOFs material, and the multi-level porous MOFs-based composite phase change material, activated carbon and microporous MOFs have synergistic effects in reducing the adsorption temperature rise and improving the adsorption capacity of low-molecular alkanes such as methane and ethane. The temperature rise of the bed in the adsorption storage device during the adsorption process is reduced, the control of adsorption heat is achieved, and the adsorption capacity of low-molecular alkanes such as methane and ethane is improved. It can effectively recover the associated gas of single-pull wells with small gas volume, low casing gas pressure, and long distance from the gathering and transportation station.

[0421] Although the present invention has been described with reference to specific embodiments, those skilled in the art will appreciate that various modifications may be made without departing from the true spirit and scope of the invention. Furthermore, the subject matter, spirit, and scope of the invention may be modified in various ways to adapt to specific circumstances, materials, combinations of materials, and methods. All such modifications are intended to be within the scope of the claims.

Claims

1. An adsorption storage device comprising an adsorption storage tank and a first bed layer and a second bed layer filled in the adsorption storage tank; The first bed layer is a composition of a multi-level porous MOFs-based composite phase change material and activated carbon; The second bed layer is a combination of a multi-level porous MOFs-based composite phase change material and a microporous MOFs material; The multi-level porous MOFs-based composite phase change material includes a multi-level porous MOFs material having micropores, mesopores and macropores, and a phase change material loaded in the macropore channels of the multi-level porous MOFs material.

2. The adsorption storage device according to claim 1, characterized in that: In the first bed, the mass ratio of the multi-level porous MOFs-based composite phase change material to the activated carbon is 2-4:1-6; In the second bed layer, the mass ratio of the multi-level porous MOFs-based composite phase change material to the microporous MOFs material is 2-4:1-6.

3. The adsorption storage device according to claim 1, characterized in that The ratio of the micropore volume, mesopore volume and macropore volume of the hierarchical MOFs material is 1-4:1-2:1; and / or The phase change material is selected from one or more of polyols, fatty acids, linear alkanes and paraffins.

4. The adsorption storage device according to claim 3, characterized in that The specific surface area of ​​the multi-level porous MOFs material is 600-1700 m 2 / g; The polyols are polyethylene glycol and / or neopentyl glycol; The fatty acid is selected from one or more of lauric acid, stearic acid, palmitic acid and pentadecanoic acid; The straight-chain alkane is selected from one or more of n-tetradecane, n-hexadecane and n-octadecane.

5. The adsorption storage device according to claim 1, wherein The specific surface area of ​​the activated carbon is 1000-1600m 2 / g; and / or The total pore volume of the activated carbon is 0.4-1.0 mL / g; and / or The micropore volume in the total pore volume is 0.2-0.7 mL / g.

6. The adsorption storage device according to claim 1, wherein The specific surface area of ​​the microporous MOFs material is 1000-1500m 2 / g; and / or The total pore volume of the microporous MOFs material is 0.5-0.8 mL / g; and / or The micropore volume in the total pore volume is 0.4-0.7 mL / g.

7. The adsorption storage device according to claim 1, characterized in that The mass ratio of the first bed layer to the second bed layer is 1-3:2-7.

8. The adsorption storage device according to claim 7, characterized in that: The mass ratio of the first bed layer to the second bed layer is 2-3:2-5.

9. The adsorption storage device according to any one of claims 1 to 8, characterized in that In the adsorption storage tank, the first bed layer and the second bed layer are sequentially filled from the proximal end to the distal end of the adsorption storage tank inlet.

10. The adsorption storage device according to any one of claims 1 to 8, characterized in that In the adsorption storage tank, the first bed layer is a cylinder coaxial with the adsorption storage tank, and the second bed layer is a ring cylinder coaxial with the adsorption storage tank; In a cross section perpendicular to the axial direction of the adsorption storage tank, the second bed layer wraps the first bed layer in an annular shape.

11. An associated gas recovery system comprising a pressurizing unit, a cooling, condensing and dehumidifying unit and an adsorption storage unit connected in sequence; The boosting unit comprises a compressor (3) and a gas-liquid separation tank (5) connected to the compressor, wherein: The compressor is used to pressurize the associated gas to produce compressed condensate and compressed gas, and the gas-liquid separation tank is used to perform a gas-liquid separation on the compressed condensate and the compressed gas; The cooling, condensing and dehumidifying unit comprises a heat exchanger (7), a condensate discharge line (19) and a condensate tank (9) connected in sequence, wherein the heat exchanger is used to cool, condense and dehumidify the compressed gas to produce dry cooling gas and condensed liquid; the condensate discharge line and the condensate tank are used to perform secondary gas-liquid separation on the dry cooling gas and the condensed liquid; The adsorption storage unit comprises an adsorption storage device (16) for adsorption storage of the dry cooling gas; The adsorption storage device is the adsorption storage device according to any one of claims 1 to 10.

12. An associated gas recovery process comprising the following steps: Providing an associated gas recovery system according to claim 11; 1) The associated gas enters the compressor (3) and is compressed and heated to obtain the compressed gas and compressed condensate, and the compressed condensate enters the gas-liquid separation tank (5) to achieve the primary gas-liquid separation; 2) passing the compressed gas obtained in step 1) into the heat exchanger (7) for cooling, condensation and dehumidification to obtain the dry cooling gas and condensed liquid, and the condensed liquid is discharged into the condensate tank (9) via the condensate discharge line (19) to achieve the secondary gas-liquid separation; 3) The dry cooling gas obtained in step 2) is passed into the adsorption storage device (16) for adsorption storage.

13. The associated gas recovery process according to claim 12, characterized in that: In step 1), the pressure of the compressed gas is 2-4 MPa and / or the temperature is 40-70° C.; and / or In step 2), the temperature of the dry cooling gas is 0-5°C.

14. Use of any one of the adsorption storage device according to any one of claims 1 to 10, the associated gas recovery system according to claim 11, and the associated gas recovery process according to claim 12 or 13 in the recovery of associated gas from a single-pull well.

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