Gas de-liquification method and its applications

Abstract

The present application relates to the field of gas drying, and specifically discloses a gas liquid removal method and application thereof. The method comprises: passing liquid-containing gas through a separation unit comprising at least two of hydrophilic and oleophobic contact pieces, oleophilic and hydrophobic contact pieces, dual-oleophobic contact pieces, and dual-hydrophilic contact pieces to obtain liquid-removed gas. The method has the characteristics of high liquid removal efficiency, sufficient liquid removal, and large liquid removal amount. The present application is particularly suitable for natural gas liquid removal. When applied to natural gas liquid removal, the present application can significantly improve the natural gas liquid removal efficiency and natural gas processing amount.

Description

Technical Field

[0001] This invention relates to the field of gas drying, and more specifically to a gas dehydration method and its application. Background Technology

[0002] Natural gas extraction and production often involves the production of underground brine and condensate. When the aqueous phase enters pipelines and downstream equipment, it causes corrosion, increases flow resistance, complicates the processing of subsequent natural gas products, and reduces the purity and calorific value of the final product. Condensate, on the other hand, has high added value and needs to be recovered promptly to avoid flow losses in downstream pipelines and equipment. Natural gas fields typically use phase separators to separate natural gas and liquid phases. However, during natural gas production, processes such as well shut-in / opening, manual drainage, well workover, and new well commissioning can result in large amounts of liquid being discharged in a short period, exceeding the phase separator's capacity and causing liquid to flow into downstream pipelines. Even during routine production, foaming or liquid entrainment can occur in the phase separator, leading to liquid entering downstream pipelines with the natural gas. Natural gas fields usually equip the phase separator with a filter separator. This filter removes solid particles such as rock cuttings and rust, and also collects liquid into droplets through the filter elements, which are then collected at the bottom of the separator by gravity and gas purging. However, the filter element can only capture large droplets and is ineffective against foam and small droplets. Therefore, liquid phase will still enter subsequent pipelines and equipment. Summary of the Invention

[0003] To address the aforementioned deficiencies in existing technologies, this invention provides a gas dehydration method and its application, which features high gas dehydration efficiency, thorough dehydration, and large processing capacity.

[0004] In a first aspect, the present invention provides a gas dehydration method, the method comprising: passing a liquid-containing gas through a separation unit comprising at least two of a hydrophilic-oleophobic contact, an oleophilic-hydrophobic contact, a bihydrophobic contact, and an amphiphilic contact to obtain a dehydrated gas.

[0005] Secondly, the present invention provides an application of the method in natural gas deliquescing.

[0006] Compared with the prior art, the present invention has the following advantages:

[0007] This invention utilizes a combination of hydrophilic and oleophobic contact elements, oleophilic and hydrophobic contact elements, dual-repellent contact elements, and amphiphilic contact elements to efficiently and specifically remove liquid from liquid-containing gases; it has high liquid removal efficiency and large processing capacity.

[0008] Applying the method of this invention to natural gas deliquescing can significantly improve natural gas deliquescing efficiency and natural gas processing capacity. Compared with existing natural gas deliquescing methods, it has the advantages of low cost, high gas deliquescing efficiency, thorough deliquescing, and large processing capacity. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of a preferred embodiment of the natural gas deliquescing process provided in Example 1;

[0010] Figure 2 This is a schematic diagram of a preferred embodiment of the natural gas deliquescing process provided in Example 2;

[0011] Figure 3 This is a schematic diagram of a preferred embodiment of the natural gas deliquescing process provided in Example 3;

[0012] Figure 4 This is a schematic diagram of a preferred embodiment of the natural gas deliquescing process provided in Example 4;

[0013] Figure 5 This is a schematic diagram of a preferred embodiment of the natural gas deliquescing process of the present invention. Detailed Implementation

[0014] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0015] The present invention provides a gas dehydration method, the method comprising: passing a liquid-containing gas through a separation unit comprising at least two of a hydrophilic-oleophobic contact, an oleophilic-hydrophobic contact, a bihydrophobic contact, and an amphiphilic contact to obtain a dehydrated gas.

[0016] The method of the present invention can efficiently and specifically remove liquid from liquid-containing gases by combining hydrophilic and oleophobic contact elements, oleophilic and hydrophobic contact elements, dual-repellent contact elements and amphiphilic contact elements.

[0017] In this invention, the arrangement of the hydrophilic-oleophobic contact, oleophilic-hydrophobic contact, amphiphilic contact, and amphiphilic contact in the separation unit is not particularly limited. According to a preferred embodiment of this invention, the separation unit may include two of the following: hydrophilic-oleophobic contact, oleophilic-hydrophobic contact, amphiphilic contact, and amphiphilic contact. This includes, for example, combinations of hydrophilic-oleophobic and oleophilic-hydrophobic contacts, combinations of hydrophilic-oleophobic and amphiphilic contacts, combinations of hydrophilic-oleophobic and amphiphilic contacts, combinations of oleophilic-hydrophobic and amphiphilic contacts, and combinations of oleophilic-hydrophobic and amphiphilic contacts. The separation unit may include three of the following: hydrophilic and oleophobic contacts, oleophilic and hydrophobic contacts, ambiphilic and amphiphilic contacts, for example, a combination of hydrophilic and oleophobic contacts, a combination of oleophilic and hydrophobic contacts and ambiphilic contacts, a combination of hydrophilic and oleophobic contacts and ambiphilic contacts, a combination of oleophilic and hydrophobic contacts and ambiphilic contacts, a combination of oleophilic and hydrophobic contacts, ambiphilic and hydrophobic contacts and amphiphilic contacts; the separation unit may also include four of the following: hydrophilic and oleophobic contacts, oleophilic and hydrophobic contacts, ambiphilic and hydrophobic contacts, and amphiphilic contacts.

[0018] In this invention, there are no special requirements on the number of hydrophilic and oleophobic contacts, oleophilic and hydrophobic contacts, amphiphilic and hydrophobic contacts in the separation unit, and the design can be selected according to the actual situation.

[0019] In this invention, as long as the objective of this invention can be achieved, there are no particular requirements regarding the volume ratio of the hydrophilic and oleophobic contact components. According to a preferred embodiment of this invention, based on the total volume of the contact components, the proportion of the hydrophilic and oleophobic contact components is 0-60% by volume, preferably 1-35% by volume. By adopting the aforementioned preferred scheme, the gas deliquescence efficiency and the amount of liquid-containing gas processed can be further improved.

[0020] In this invention, as long as the objective of the invention can be achieved, the volume ratio of the oleophilic and hydrophobic contact is not particularly required. According to a preferred embodiment of the invention, based on the total volume of the contact, the proportion of the oleophilic and hydrophobic contact is 0-60% by volume, preferably 1-35% by volume. By adopting the aforementioned preferred scheme, the gas deliquescence efficiency and the amount of liquid-containing gas processed can be further improved.

[0021] In this invention, as long as the objective of this invention can be achieved, the volume ratio of the dual-repellent contact element is not particularly required. According to a preferred embodiment of this invention, based on the total volume of the contact element, the proportion of the dual-repellent contact element is 0-60% by volume, preferably 1-35% by volume. By adopting the aforementioned preferred scheme, the gas deliquescence efficiency and the amount of liquid-containing gas processed can be further improved.

[0022] In this invention, as long as the objective of this invention can be achieved, the volume ratio of the amphiphilic contact is not particularly required. According to a preferred embodiment of this invention, based on the total volume of the contact, the proportion of the amphiphilic contact is 0-60% by volume, preferably 1-35% by volume. By adopting the aforementioned preferred scheme, the gas deliquescence efficiency and the amount of liquid-containing gas processed can be further improved.

[0023] According to a preferred embodiment of the present invention, the liquid-containing gas is selected from one or more of natural gas, methane, nitrogen, air, and carbon dioxide.

[0024] According to a preferred embodiment of the present invention, the liquid phase is selected from water, condensate oil, fracturing fluid, flowback fluid and / or organic solvent, preferably from one or both of water and condensate oil.

[0025] In this invention, the method for preparing the hydrophilic and oleophobic contact can be a conventional method in the art. According to a preferred embodiment of this invention, the method for preparing the hydrophilic and oleophobic contact includes modifying the contact with a hydrophilic and oleophobic modifier.

[0026] In this invention, the method for preparing the oleophilic and hydrophobic contact can be a conventional method in the art. According to a preferred embodiment of this invention, the method for preparing the oleophilic and hydrophobic contact includes modifying the contact with an oleophilic and hydrophobic modifier.

[0027] In this invention, the preparation method of the bihydrophobic contact can be a conventional method in the art. According to a preferred embodiment of this invention, the preparation method of the bihydrophobic contact includes modifying the contact with a bihydrophobic modifier.

[0028] In this invention, the preparation method of the amphiphilic contact can be a conventional method in the art. According to a preferred embodiment of this invention, the preparation method of the amphiphilic contact includes modifying the contact with an amphiphilic modifier.

[0029] In this invention, the hydrophilic-oleophobic modifier can be a conventional choice in the art. According to a preferred embodiment of the invention, the hydrophilic-oleophobic modifier is selected from at least one of the following: hydrophilic polymers, hydrophilic dyes, hydrophilic silanes, ionic surfactants with concentrations higher than the critical micelle concentration, polyether nonionic surfactants, alkaline solutions, metal oxides, quaternary ammonium compounds, nanoparticles grafted with ionic groups, nanoparticles grafted with hydroxyl groups, proteins, cellulose, and hydrophilic paints. Preferably, it is at least one of the following: hydrophilic polymers, alkaline solutions, hydrophilic dyes, and hydrophilic silanes; more preferably, it is at least one of polyvinylpyrrolidone, sodium bicarbonate solution, polyhydroxyalkyl azo dyes, and polyether silanes. By adopting the aforementioned preferred embodiment, the gas deliquidation efficiency and the amount of liquid-containing gas that can be processed can be further improved.

[0030] In this invention, the oleophilic-hydrophobic modifier can be a conventional choice in the art. According to a preferred embodiment of the invention, the oleophilic-hydrophobic modifier is selected from at least one of hydrophobic polymers, ionic surfactants with concentrations below the critical micelle concentration, alkylsilane chemicals, alkyl-grafted nanoparticles, aromatic hydrocarbon-grafted nanoparticles, and oleophilic paints. Preferably, it is selected from at least one of alkylsilane chemicals and ionic surfactants with concentrations below the critical micelle concentration; more preferably, it is selected from at least one of dodecyltrimethoxysilane and hexadecyltrimethylammonium with concentrations below the critical micelle concentration. By adopting the aforementioned preferred embodiment, the gas deliquidation efficiency and the amount of liquid-containing gas that can be processed can be further improved.

[0031] In this invention, the amphiphilic modifier can be a conventional choice in the art. According to a preferred embodiment of the invention, the amphiphilic modifier is selected from at least one of fluoropolymers, fluorinated surfactants, fluorinated silane chemicals, fluorinated group-grafted nanoparticles, and amphiphilic coating paints, preferably from at least one of fluoropolymers, fluorinated surfactants, and fluorinated silane chemicals, and more preferably from at least one of polytetrafluoroethylene, perfluoroalkyl sulfonates, and perfluorosilanes. By adopting the aforementioned preferred embodiment, the gas deliquidation efficiency and the liquid-containing gas processing capacity can be further improved.

[0032] In this invention, the amphiphilic modifier can be a conventional choice in the art. According to a preferred embodiment of the invention, the amphiphilic modifier is selected from at least one of nano-metal coatings, long-chain polyether surfactants, aromatic polyether surfactants, polyhydroxy coatings, alkyl polyether nanoparticles, and aromatic polyether-grafted nanoparticles. Preferably, it is selected from at least one of nano-metal coatings, long-chain polyether surfactants, polyether nanoparticles, and polyhydroxy coatings; more preferably, it is selected from at least one of nano-zirconia, nonylphenol dodecyl ether, and dodecyl polyglycoside. By adopting the aforementioned preferred embodiment, the gas deliquescence efficiency and the amount of liquid-containing gas processed can be further improved.

[0033] In this invention, the modification method for each contact element is not particularly required as long as the objective of the invention can be achieved. According to a preferred embodiment of the invention, the modification method for each contact element is one or both of chemical modification and physical modification, preferably at least one of immersion, coating, adsorption, or etching. By adopting the aforementioned preferred solution, the gas deliquescence efficiency and the liquid-containing gas processing capacity can be further improved.

[0034] In this invention, each of the contact elements can be a conventional choice in the art. According to a preferred embodiment of the invention, each of the contact elements is selected from at least one of baffles, coalescing plates, rectifiers, mist eliminators, filters, packing, or trays. By adopting the aforementioned preferred solution, the gas deliquescence efficiency and the liquid-containing gas throughput can be further improved.

[0035] In this invention, the material forming the contact can be a conventional choice in the art. According to a preferred embodiment of the invention, the material forming the contact is selected from at least one of metal, ceramic, glass, cotton fiber, polyamide fiber, polyester fiber, and wood. By adopting the aforementioned preferred solution, the gas deliquescence efficiency and the amount of liquid-containing gas that can be processed can be further improved.

[0036] According to a preferred embodiment of the present invention, a phase separator is used for gas-liquid separation:

[0037] The baffles, coalescing plates, and rectifiers in the phase separator are modified using an amphiphilic modifier;

[0038] The outer layer of the mist eliminator is modified with an amphiphilic modifier; the middle layer is partially modified with a hydrophilic-oleophobic modifier and the other part is modified with an oleophilic-hydrophobic modifier; the inner layer is modified with an amphiphilic modifier to obtain a modified phase separator.

[0039] Specifically, when using a phase separator for liquid removal, the baffles, coalescing plates, and rectifiers of the phase separator are soaked in an amphiphilic modifier such as nano-zirconia to obtain amphiphilic contact parts. The outer metal mesh of the multi-layer metal mesh structure mist eliminator is soaked in an amphiphilic modifier such as nano-zirconia to obtain amphiphilic contact parts, part of the middle metal mesh is soaked in a hydrophilic and oleophobic modifier such as polyvinylpyrrolidone to obtain hydrophilic and oleophobic contact parts, part of the middle metal mesh is soaked in an oleophilic and hydrophobic modifier such as dodecyltrimethoxysilane to obtain oleophilic and hydrophobic contact parts, and the inner metal mesh is coated with an amphiphilic modifier such as polytetrafluoroethylene to obtain amphiphilic contact parts.

[0040] According to a preferred embodiment of the present invention, when using filter cloth for liquid removal:

[0041] Amphiphilic modification of filter cloth: The filter cloth is modified using an amphiphilic modifier;

[0042] Hydrophilic and oleophobic modification of filter cloth: The filter cloth is modified with a hydrophilic and oleophobic modifier;

[0043] Oil- and hydrophobic modification of filter cloth: The nylon cloth is initially modified with an oil- and hydrophobic modifier; then it is further modified with an oil- and hydrophobic modifier.

[0044] Amphiphilic modification of filter cloth: The filter cloth is modified with an amphiphilic modifier;

[0045] The modified filter cloths described above can be combined arbitrarily to obtain separation unit filter elements.

[0046] Specifically, the outer layer of the filter element is an amphiphilic contact element woven from multiple sheets of polyester filter cloth woven with an amphiphilic modifier such as nano-zirconia; the middle layer is a mixed contact element woven from multiple sheets of polyester filter cloth woven with a hydrophilic and oleophobic modifier such as polyhydroxyalkyl azo and an oleophilic and hydrophobic modifier such as dodecyltrimethoxysilane; and the inner layer is a bihydrophobic contact element woven from polyester filter cloth woven with an amphiphilic modifier such as perfluorosilane.

[0047] According to a preferred embodiment of the present invention, liquid removal is performed using a packed tower:

[0048] Amphiphilic modification of fillers: The fillers are modified using amphiphilic modifiers;

[0049] Hydrophilic and oleophobic modification of the filler: The filler filter cloth is modified with a hydrophilic and oleophobic modifier; then further modified with a hydrophilic and oleophobic modifier.

[0050] Hydrophobic and oleophilic modification of fillers: The fillers are initially modified using hydrophobic and oleophilic modifiers; then further modified using hydrophobic and oleophilic modifiers.

[0051] Amphiphilic modification of fillers: The fillers are modified using amphiphilic modifiers;

[0052] The aforementioned modified packing materials are randomly combined and filled into a packed tower to form a separation unit.

[0053] Specifically, in the packed tower, ceramic packing modified with hydrophilic and oleophobic modifiers such as polyvinylpyrrolidone and ceramic packing modified with oleophilic and hydrophobic modifiers such as dodecyltrimethoxysilane are uniformly mixed and placed in the lower layer of the packed tower, while ceramic packing modified with a dual-hydrophobic modifier such as perfluorosilane is packed in the upper layer of the packed tower.

[0054] This invention provides a gas dehydration method, which is carried out in a gas dehydration system comprising an inlet device, a rotating device, a filtering device, and an outlet device.

[0055] The air intake device is connected to the filter device, so that the liquid-containing gas can be pressurized by the air intake device and then passed into the filter device to remove the liquid and obtain dehydrated gas.

[0056] The filter device is fixedly mounted on the rotating rod of the rotating device, so that the filter device can rotate and the centrifugal force generated can remove the liquid phase retained in the filter device. The filter device includes at least two types of contact elements selected from hydrophilic and oleophobic contact elements, oleophilic and hydrophobic contact elements, dual-hydrophobic contact elements, and amphiphilic contact elements.

[0057] The gas outlet device is located inside the rotating rod and is connected to the filter device through an opening on the rotating rod, so that the deliquescent natural gas that has been deliquescented in the filter device can be enriched and discharged from the system.

[0058] The filtration device includes at least two types of contacts selected from hydrophilic and oleophobic contacts, oleophilic and hydrophobic contacts, dual-hydrophobic contacts, and amphiphilic contacts.

[0059] The method includes:

[0060] (1) The filter device rotates with the rotating device, wherein the rotation speed is 1-10000 r / min;

[0061] (2) The liquid-containing gas is sent into the filter device through the air inlet device to obtain liquid-removed gas. The obtained liquid-removed gas enters the gas outlet device for enrichment through the opening on the rotating rod of the rotating device. The gas velocity of the liquid-containing gas is 0.1-2 million cubic meters / day.

[0062] This method ensures the sustainability of liquid removal and further improves the liquid removal efficiency of the gas.

[0063] The hydrophilic-oleophobic contact, oleophilic-hydrophobic contact, amphiphilic contact, and amphiphilic contact have been described in detail above and are cited together, and will not be repeated here.

[0064] This invention provides an application of the method in natural gas deliquescence.

[0065] Applying the method of this invention to natural gas dehydration can significantly improve the dehydration efficiency and throughput. Compared with existing natural gas dehydration methods, it has the advantages of low cost, large throughput, and high dehydration efficiency.

[0066] According to a preferred embodiment of the present invention, such as Figure 1 As shown,

[0067] The surfaces of baffles, coalescing plates and rectifiers are modified by immersion using amphiphilic modifiers such as nano-zirconia, maintaining a certain temperature and time, such as 55°C and 96 hours, and then removed and air-dried.

[0068] The mist eliminator is a metal mesh type mist eliminator. The mist eliminator is manufactured by modifying the metal mesh as follows:

[0069] Amphiphilic surface modification: The metal mesh is immersed in an amphiphilic modifier such as a nano-zirconia dispersion, and maintained at a certain temperature and time, such as 55°C and 96 hours, and then removed and dried.

[0070] Hydrophilic and oleophobic surface modification: Immerse the metal mesh in a hydrophilic and oleophobic modifier such as polyvinylpyrrolidone for a certain period of time, such as 60 minutes, then take it out and dry it; then immerse it again in a hydrophilic and oleophobic modifier such as polyvinylpyrrolidone for a certain period of time, such as 60 minutes, then take it out and dry it.

[0071] Oleophilic and hydrophobic surface modification: Immerse the metal mesh in an oleophilic and hydrophobic modifier such as dodecyltrimethoxysilane for a certain time, such as 20 minutes, then remove and air dry; then immerse it again in an oleophilic and hydrophobic modifier such as dodecyltrimethoxysilane for a certain time, such as 20 minutes, then remove and air dry.

[0072] Bihydrophobic surface modification: Coating the surface of a metal mesh with a bihydrophobic modifier, such as a polytetrafluoroethylene film, of a certain thickness, for example 20 micrometers.

[0073] After deliquescing, the natural gas flows into subsequent pipelines and equipment through the "natural gas outlet," wastewater is discharged through the "water outlet," and condensate oil is recovered through the "oil outlet."

[0074] According to a preferred embodiment of the present invention, such as Figure 2 As shown,

[0075] The filter element is manufactured using a composite surface-modified material, and the filter element material is polyester filter cloth.

[0076] Amphiphilic modification of polyester filter cloth: Soak polyester filter cloth in an amphiphilic modifier such as nano-zirconia dispersion, maintain a certain temperature and time such as 55℃ and 4 hours, and then take it out and air dry.

[0077] Hydrophilic and oleophobic modification of polyester filter cloth: Soak the polyester filter cloth in a hydrophilic and oleophobic modifier such as a polyhydroxyalkyl azo solution for a certain period of time, such as 1 hour, and then take it out and dry it.

[0078] Oil- and hydrophobic modification of polyester filter cloth: Soak the polyester filter cloth in an oil- and hydrophobic modifier such as dodecyltrimethoxysilane for a certain time, such as 20 minutes, then take it out and dry it; then soak it again in an oil- and hydrophobic modifier such as dodecyltrimethoxysilane for a certain time, such as 20 minutes, then take it out and dry it.

[0079] Bisphosphochemical modification of polyester filter cloth: A biphosphochemical modifier, such as perfluorosilane, is sprayed onto the surface of the polyester filter cloth.

[0080] The outer layer of the filter element is an amphiphilic layer, woven from multiple, for example, 100 sheets of amphiphilic polyester filter cloth; the middle layer is a hydrophilic-oleophobic-oleophobic mixed layer, woven from multiple, for example, 100 sheets of hydrophilic polyester filter cloth and multiple, for example, 100 sheets of hydrophobic polyester filter cloth arranged in sequence; the inner layer is a double-hydrophobic layer, woven from multiple, for example, 100 sheets of double-hydrophobic polyester filter cloth.

[0081] When natural gas enters through the inlet, the liquid phase it carries is removed by the filter element. The deliquescent natural gas flows out through the outlet, and the removed liquid flows out through the drain port for subsequent oil-water separation.

[0082] According to a preferred embodiment of the present invention, such as Figure 3 As shown,

[0083] Packed tower type natural gas deliquencing, the packing material is ceramic packing:

[0084] Hydrophilic and oleophobic surface modification: Immerse the ceramic filler in a hydrophilic and oleophobic modifier such as polyvinylpyrrolidone for a certain period of time, such as 60 minutes, and then air dry; then immerse it again in a hydrophilic and oleophobic modifier such as polyvinylpyrrolidone for a certain period of time, such as 60 minutes, and then take it out and air dry.

[0085] Oleophilic and hydrophobic surface modification: Immerse the ceramic filler in an oleophilic and hydrophobic modifier such as dodecyltrimethoxysilane for a certain time, such as 60 minutes, then take it out and air dry it; then immerse it again in an oleophilic and hydrophobic modifier such as dodecyltrimethoxysilane for a certain time, such as 60 minutes, then take it out and air dry it.

[0086] Bi-repellent surface modification: Immerse the ceramic filler in a bi-repellent modifier such as perfluorosilane for a certain period of time, such as 30 minutes, and then take it out and let it dry.

[0087] The lower layer of the packed tower is filled with a mixture of hydrophilic and oleophobic packing materials to a certain thickness, such as 1 meter; the upper layer is filled with a mixture of hydrophilic and oleophobic packing materials to a certain thickness, such as 2 meters.

[0088] When the liquid-carrying natural gas flows from bottom to top through the packing material, it is then discharged through the drain port and enters the oil-water separator to recover the condensate oil; a small portion of the liquid phase flows upward and is then blocked by the dual-hydrophobic material; the deliquescent natural gas enters the subsequent process through the outlet.

[0089] According to a preferred embodiment of the present invention, such as Figure 4 The natural gas deliquescing system shown is

[0090] Surface modification of hydrophilic and oleophobic layer: Immerse the metal mesh in a hydrophilic and oleophobic modifier such as polyvinylpyrrolidone, take it out and let it dry; then immerse it again in a hydrophilic and oleophobic modifier such as polyvinylpyrrolidone, take it out and let it dry.

[0091] Surface modification of oleophilic and hydrophobic layer: Immerse the metal mesh in an oleophilic and hydrophobic modifier such as dodecyltrimethoxysilane, remove it and air dry it; then immerse it again in an oleophilic and hydrophobic modifier such as dodecyltrimethoxysilane, remove it and air dry it.

[0092] Bihydrophobic surface modification: A bihydrophobic modifier, such as a polytetrafluoroethylene film, with a certain thickness, such as 20 micrometers, is coated on the surface of a metal mesh.

[0093] Filter unit structure: The filter unit frame is made of metal with perforations, for example, 10cm in diameter. The frame is covered with a surface-modified metal mesh, such as... Figure 4 As shown, the innermost layer is a double-hydrophobic filter layer composed of multiple sheets, such as 10-30 sheets of double-hydrophobic stainless steel mesh; the outer layer is a composite filter layer formed by alternating multiple sheets, such as 2-10 sheets of oleophilic and hydrophobic stainless steel mesh composed of oleophilic and hydrophobic filter layers and multiple sheets, such as 2-10 sheets of hydrophilic and oleophobic stainless steel mesh composed of hydrophilic and oleophobic stainless steel mesh, for example, 2-5 times.

[0094] The filter unit is fixed to and encloses the hollow rotating rod. Natural gas passes through the filter unit for deliquescing. The deliquesced natural gas enters the rotating rod through openings and flows out from the natural gas outlet. Figure 4 As shown.

[0095] During operation, the centrifugal force of the rotating device is used to remove the liquid phase adhering to the filter unit.

[0096] The present invention will be further described below through specific embodiments. However, the scope of the present invention is not limited to the scope covered by the embodiments.

[0097] Example 1

[0098] Natural gas dehydration using a phase separator:

[0099] like Figure 1 Hydrophilic-oleophilic modification of the baffles, coalescing plates, and rectifiers in the phase separator can increase the efficiency of absorbing and intercepting the liquid phase. When natural gas carrying the liquid phase passes through the baffles, coalescing plates, and rectifiers made of amphiphilic modified materials, the liquid phase is adsorbed and aggregated on the solid surface, and then flows to the bottom of the phase separator and is discharged by gravity.

[0100] In this embodiment, the surface of the contact was modified using a 0.5% by mass fraction of nano-zirconia amphiphilic modifier. The contact was immersed in a 0.5% by mass fraction of nano-zirconia dispersion at 55°C for 96 hours, and then removed and air-dried.

[0101] The mist eliminator has an outer amphiphilic layer, a middle layer of a hybrid hydrophilic-oleophobic and oleophobic-hydrophobic layer, and an inner double-phobic layer. When liquid natural gas comes into contact with the outer amphiphilic layer, water mist and oil mist adsorb onto the surface and agglomerate into large droplets. When the droplets enter the hybrid hydrophilic-oleophobic layer, the aqueous and oil phases generate strong attraction to the hydrophilic and oleophobic surfaces, respectively, thus creating flow viscosity; simultaneously, the continuous channels of the aqueous and oil phases are interrupted, increasing their tortuous movement. All of these factors reduce the relative permeability of the liquid phase, thus hindering its advancement, while the gas remains largely unaffected. Finally, a small amount of liquid phase is blocked by the strong capillary force of the double-phobic layer and cannot penetrate the mist eliminator.

[0102] In this embodiment, the raw material for the mist eliminator is a 316 stainless steel mesh with a pore size of 200-500 micrometers and a thickness of 0.1-1 cm. After the following modifications, a mist eliminator is manufactured with the following structure: the lower part is composed of 20 sheets of amphiphilic 316 stainless steel mesh stacked together; the middle part is formed by alternating layers of 5 sheets of oleophilic and hydrophobic stainless steel mesh and 5 sheets of hydrophilic and oleophobic stainless steel mesh stacked together; and the upper part is composed of 20 sheets of double hydrophobic 316 stainless steel mesh stacked together.

[0103] Amphiphilic surface modification: A stainless steel 316 mesh with a pore size of 200-500 micrometers and a thickness of 0.1-1 cm is immersed in a 0.5% mass fraction nano-zirconia dispersion, maintained at 55°C for 96 hours, and then removed and air-dried.

[0104] Hydrophilic and oleophobic surface modification: Immerse a stainless steel 316 mesh with a pore size of 200-500 micrometers and a thickness of 0.1-1 cm in polyvinylpyrrolidone for 60 minutes, remove it and air dry at room temperature; then immerse it in polyvinylpyrrolidone again for 60 minutes, remove it and air dry at room temperature.

[0105] Surface modification of oleophilic and hydrophobic layer: Immerse a stainless steel 316 mesh with a pore size of 200-500 micrometers and a thickness of 0.1-1 cm in dodecyltrimethoxysilane for 20 minutes, remove it and air dry at room temperature; then immerse it again in dodecyltrimethoxysilane for 20 minutes, remove it and air dry at room temperature.

[0106] Double-layer surface modification: Coating the surface of a 316 stainless steel mesh with a pore size of 200-500 micrometers and a thickness of 0.1-1cm with a 20-micrometer thick polytetrafluoroethylene film.

[0107] After deliquescing, the natural gas flows into subsequent pipelines and equipment through the "natural gas outlet," wastewater is discharged through the "water outlet," and condensate oil is recovered through the "oil outlet."

[0108] In the application of natural gas gathering and transmission stations, the daily processing capacity is 2 million cubic meters of natural gas, and the daily liquid discharge is 600 cubic meters.

[0109] Example 2

[0110] Filter-type natural gas dehydration:

[0111] like Figure 2 The filter element is manufactured using a composite surface-modified material. This gives the outer layer amphiphilic properties, enhancing its ability to absorb and collect liquids; the middle layer is a hydrophilic-oleophobic / oleophilic-hydrophobic hybrid layer, reducing the fluidity of the liquid phase; and the inner layer is a microporous dual-hydrophobic material, preventing the liquid phase from entering the filter element, thus achieving natural gas deliquescence. When natural gas enters through the inlet, the liquid phase it carries is removed by the filter element. The deliquescent natural gas flows out through the outlet, and the removed liquid flows out through the drain port for subsequent oil-water separation.

[0112] The filter element is made of polyester filter cloth.

[0113] Amphiphilic modification of polyester filter cloth: The filter cloth was immersed in a 0.5% by mass nano-zirconia dispersion, maintained at 55°C for 4 hours, and then removed and air-dried.

[0114] Hydrophilic and oleophobic modification of polyester filter cloth: The filter cloth was soaked in 10% NaOH solution at 80℃ for 1 hour, then soaked in 10% polyhydroxyalkyl azo solution for 1 hour, and then dried at 50℃ for 4 hours.

[0115] Oil- and hydrophobic modification of polyester filter cloth: The filter cloth was soaked in dodecyltrimethoxysilane for 20 minutes, then removed and air-dried at room temperature; then it was soaked in dodecyltrimethoxysilane again for 20 minutes, then removed and air-dried at room temperature.

[0116] Bi-repellent modification of polyester filter cloth: Spray perfluorosilane on the surface of the filter cloth and then dry it at 30°C for 4 hours;

[0117] The outer layer, the amphiphilic layer, is woven from 100 layers of amphiphilic polyester filter cloth; the middle layer, a hydrophilic-oleophobic-oleophobic mixed layer, is woven from 100 layers of hydrophilic polyester filter cloth and 100 layers of hydrophobic polyester filter cloth arranged in sequence; the double-hydrophobic layer is woven from 100 layers of double-hydrophobic polyester filter cloth.

[0118] In applications at natural gas fields and processing plants, the daily processing capacity is 2 million cubic meters of natural gas, with a daily discharge volume of 800 cubic meters.

[0119] Example 3

[0120] Packed tower type natural gas deliquencing:

[0121] like Figure 3Hydrophilic-oleophobic and oleophilic-hydrophobic packing materials are uniformly mixed and placed in the lower layer of a packed tower, while the dual-hydrophobic packing material is packed in the upper layer. When liquid-laden natural gas flows upward through the packing material, the mist-like liquid phase is first absorbed by the hydrophilic and oleophilic packing materials, agglomerating into large droplets. Simultaneously, the liquid phase cannot form a continuous channel, exhibiting low relative permeability and high flow resistance. Most of the liquid phase is drawn to the bottom of the packed tower by gravity and then discharged through the drain port into an oil-water separator to recover condensate oil; a small portion of the liquid phase flows upward and is then blocked by the dual-hydrophobic material. The deliquescent natural gas enters subsequent processes through the outlet.

[0122] The packing material is ceramic packing:

[0123] Hydrophilic and oleophobic surface modification: Immerse ceramic fillers with a size of about 0.1-10mm in polyvinylpyrrolidone for 60 minutes, remove them and air dry at room temperature; then immerse them in polyvinylpyrrolidone again for 60 minutes, remove them and air dry at room temperature.

[0124] Oleophilic and hydrophobic surface modification: Immerse ceramic fillers with a size of approximately 0.1-10 mm in dodecyltrimethoxysilane for 60 minutes, remove them, and air dry at room temperature; then immerse them again in dodecyltrimethoxysilane for 60 minutes, remove them, and air dry at room temperature.

[0125] Dual-hydrophobic surface modification: Immerse ceramic fillers with a size of about 0.01-1mm in perfluorosilane for 30 minutes, then remove and air dry at room temperature;

[0126] The lower layer of the packed tower is a mixed layer with a thickness of 1 meter, consisting of a mixture of hydrophilic and oleophobic packing materials, while the upper layer is a double-hydrophobic layer with a thickness of 2 meters, consisting of double-hydrophobic packing materials.

[0127] In applications at natural gas processing stations, the daily processing capacity is 2 million cubic meters of natural gas, with a daily discharge volume of 700 cubic meters.

[0128] Example 4

[0129] Rotary natural gas dehydration unit with surface-modified metal mesh as the filtration unit:

[0130] Surface modification of hydrophilic and oleophobic layer: Immerse a stainless steel 316 mesh with a pore size of 200-500 micrometers and a thickness of about 0.1-1 cm in polyvinylpyrrolidone for 60 minutes, remove it and air dry at room temperature; then immerse it in polyvinylpyrrolidone again for 60 minutes, remove it and air dry at room temperature.

[0131] Surface modification of oleophilic and hydrophobic layer: Immerse a stainless steel 316 mesh with a pore size of 200-500 micrometers and a thickness of about 0.1-1 cm in dodecyltrimethoxysilane for 20 minutes, remove it and air dry at room temperature; then immerse it again in dodecyltrimethoxysilane for 20 minutes, remove it and air dry at room temperature.

[0132] Double-layer surface modification: A 20-micron thick polytetrafluoroethylene film is coated on the surface of a stainless steel 316 metal mesh with a pore size of 80-200 micrometers and a thickness of about 0.1-1 cm.

[0133] Filter unit structure: The filter unit frame is made of 316 stainless steel with a 10cm opening. The frame is covered with a surface-modified metal mesh, such as... Figure 4 As shown. The innermost layer is composed of 20 double-hydrophobic stainless steel meshes; the middle layer is formed by alternating layers of 5 oleophilic and hydrophobic 316 stainless steel meshes and 5 hydrophilic and oleophobic 316 stainless steel meshes; the outermost layer is composed of 20 double-hydrophobic stainless steel meshes, with a total thickness of 30cm.

[0134] The filter unit is fixed to the hollow rotating rod and encloses it, allowing only natural gas feedstock to pass through the filter unit at a gas velocity of 2 million cubic meters per day; deliquesced natural gas enters the rotating rod at a gas velocity of 150,000 cubic meters per day through an opening (25 cm in diameter) and flows out from the natural gas outlet. Figure 4 As shown.

[0135] During operation, the centrifugal force of the rotating device is used to remove the liquid phase adhering to the filter unit. The rotation speed is 200 revolutions per minute.

[0136] In its application at the natural gas processing station, it processes 2 million cubic meters of natural gas per day and discharges 900 cubic meters of liquid per day. Its continuous operating time is longer than that of Example 2.

[0137] Example 5

[0138] Amphiphilic modification of polyester filter cloth: The filter cloth is soaked in 1% by mass of docosyl polyether surfactant for 24 hours, and then taken out and dried.

[0139] Hydrophilic and oleophobic modification of polyester filter cloth: The filter cloth was soaked in 10% NaOH solution at 80℃ for 1 hour, then soaked in 1% alkyl polyether carboxylate surfactant for 24 hours, and then taken out and dried.

[0140] Oleophilic and hydrophobic modification of polyester filter cloth: Coat the filter cloth with a layer of oleophilic paint and let it dry at room temperature;

[0141] Bi-repellent modification of polyester filter cloth: Spray polytetrafluoroethylene on the surface of the filter cloth and let it dry at room temperature;

[0142] This method can process 1 million cubic meters of natural gas per day and remove 200 cubic meters of liquid per day.

[0143] Comparative Example 1

[0144] Same as Example 2, except that the material is not modified.

[0145] This method can initially process small amounts of natural gas, but as the aqueous and oil phases accumulate, the filter cloth loses its liquid removal function and blocks the gas passages.

[0146] In summary, the method of the present invention can efficiently and effectively remove liquid from liquid-containing gases, with high deliquescence efficiency and large processing capacity.

[0147] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention. This includes combining various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not further describe the various possible combinations. However, these simple modifications and combinations should also be considered as part of the content disclosed in this invention and are all within the protection scope of this invention.

Claims

1. A gas-liquid separation method, characterized in that, The method includes: passing a liquid-containing gas through a separation unit comprising four types of a hydrophilic-oleophobic contact, an oleophilic-hydrophobic contact, a bihydrophobic contact, and an amphiphilic contact to obtain a deliquescent gas; The method for preparing the hydrophilic and oleophobic contact includes modifying the contact with a hydrophilic and oleophobic modifier; the hydrophilic and oleophobic modifier is at least one of polyvinylpyrrolidone, sodium bicarbonate solution, polyhydroxyalkyl azo and polyether silane. The method for preparing the oleophilic and hydrophobic contact includes modifying the contact with an oleophilic and hydrophobic modifier; the oleophilic and hydrophobic modifier is selected from at least one of dodecyltrimethoxysilane and hexadecyltrimethylammonium with a concentration below the critical micelle concentration. Based on the total volume of the contact components, the proportion of hydrophilic and oleophobic contact components is 1-35% by volume, the proportion of oleophilic and hydrophobic contact components is 1-35% by volume, the proportion of amphiphilic contact components is 1-35% by volume, and the proportion of amphiphilic contact components is 1-35% by volume. Each of the contact elements is selected from at least one of baffles, coalescing plates, rectifiers, mist eliminators, filters, packing, and trays; the material forming the contact element is selected from at least one of metals, ceramics, glass, cotton fibers, polyamide fibers, polyester fibers, and wood.

2. The method according to claim 1, wherein, In the separation unit The gas phase in the liquid-containing gas is selected from one or more of air, nitrogen, natural gas, methane, and carbon dioxide.

3. The method according to claim 2, wherein, The gas phase in the liquid-containing gas is natural gas and methane.

4. The method according to claim 1, wherein, The method for preparing the amphiphilic contact includes modifying the contact with an amphiphilic modifier; and / or The method for preparing the amphiphilic contact includes modifying the contact with an amphiphilic modifier.

5. The method according to claim 4, wherein, The dual-hydrophobic modifier is selected from at least one of fluoropolymers, fluorinated surfactants, fluorinated silane chemicals, fluorinated group-grafted nanoparticles, and dual-hydrophobic coating paints.

6. The method according to claim 5, wherein, The amphiphilic modifier is selected from at least one of fluoropolymers, fluorosurfactants, and fluorosilane chemicals.

7. The method according to claim 5, wherein, The amphiphilic modifier is selected from at least one of polytetrafluoroethylene, perfluoroalkyl sulfonates, and perfluorosilanes.

8. The method according to claim 4, wherein, The amphiphilic modifier is selected from at least one of nano-zirconia, long-chain polyether surfactants, aromatic polyether surfactants, polyhydroxy coatings, alkyl polyether nanoparticles, and aromatic polyether-grafted nanoparticles.

9. The method according to claim 8, wherein, The amphiphilic modifier is selected from at least one of nano-zirconia, long-chain polyether surfactants, alkyl polyether nanoparticles, and multi-hydroxyl coatings.

10. The method according to claim 4, wherein, The amphiphilic modifier is selected from at least one of nano-zirconia, nonylphenol dodecyl polyether, and dodecyl polyglycoside.

11. The method according to claim 4, wherein, The modification method for each contact element is one or both of chemical modification and physical modification.

12. The method according to claim 11, wherein, The modification method for each contact element is at least one of immersion, coating, adsorption, and etching.

13. The application of the method according to any one of claims 1-12 in natural gas deliquescence.

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