Continuous gas separation system coupled with multistage hydrate-membrane process

Abstract

The application discloses a kind of multistage hydrate method combined membrane method gas continuous separation system.The system includes: hydrate generation ring, inlet is provided with disturbance device;Hydrate generation ring includes N level, and the cyclonic separator of N level is provided on hydrate generation ring, and hydrate generation ring and cyclonic separator equal number, and interval arrangement;Hydrate decomposition system, hydrate decomposition system is provided with first outlet and second outlet, first outlet is connected with water inlet unit, and is connected with the liquid inlet of disturbance device;Membrane separation unit is connected with the first outlet of N level cyclonic separator, and membrane separation unit is provided with product gas outlet.The system of the application adopts multistage separation process, avoids the separation effect that cannot be reached when adopting single-stage separation.This application can realize the efficient continuous separation of gas.

Description

Technical Field

[0001] This invention relates to the field of hydrate-based technology, specifically to a continuous gas separation system coupled with a hydrate-membrane method. Background Technology

[0002] Natural gas hydrates are abundant on Earth and represent a significant potential energy source globally. In the context of the energy crisis, their investigation and research have become a global focus. They are ice-like crystalline compounds composed of water and natural gas, formed under high pressure and low temperature. With ongoing research into the basic physical properties, microstructure, thermodynamics, and kinetics of hydrates, abundant reserves of natural gas hydrates have been discovered in frozen zones and the deep ocean, attracting significant attention worldwide. Besides their potential as a clean energy source, the technology for utilizing natural gas hydrates has been found to be a promising new technology that can benefit humanity.

[0003] Hydrate-based gas separation processes have been extensively studied, but hydrate-based gas separation methods also have their own problems. First, most current research is based on small-scale laboratory equipment. Furthermore, these studies all use batch or semi-batch separation methods. In batch operations, continuous production of purified gas requires two or more reactors, and the gas phase cannot be simultaneously extracted from the reactor forming hydrates. Gas separation cannot be continuous, and the aqueous solution used for hydrate formation is not recycled. Second, hydrate formation becomes more demanding as the concentration of the target gas decreases. In short, a single hydrate-based gas separation technology cannot completely capture the target gas from a gas mixture. Additionally, single-stage separation using gas hydrates often fails to meet industrial requirements. Therefore, to apply hydrate-based gas separation technology to industry, it is necessary to develop staged continuous gas separation processes and new separation methods that couple hydrate methods with other separation methods.

[0004] Currently, patent CN106474904A discloses a CO2 gas separation device and method combining hydrate method and chemical absorption method, which can achieve efficient and continuous separation of CO2. Although this method has low energy consumption, the hydrate reaction is incomplete. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] The purpose of this invention is to provide a multi-stage hydrate-membrane coupled continuous gas separation system for separating gases A and B. Different gases form hydrates under different conditions. When gas mixture A / B forms hydrates, component A, which readily forms hydrates, accumulates in the hydrate phase, thus achieving gas separation. This method couples the hydrate method with the membrane method, achieving both A-poor hydrate separation and A-rich separation. The process employs a multi-stage separation process, avoiding the separation effects that cannot be achieved with single-stage separation. Furthermore, the cyclone mixer used in the process increases gas-liquid mass transfer, enabling efficient hydrate formation. The spiral pipes of different diameters not only enhance radial mixing but also generate Dean vortices, promoting mixing. This invention enables efficient and continuous gas separation.

[0007] (II) Technical Solution

[0008] To address the aforementioned technical problems, this invention provides a multi-stage hydrate-membrane coupled continuous gas separation system.

[0009] This invention provides a multi-stage hydrate-membrane coupled continuous gas separation system, comprising:

[0010] A hydrate-generating ring channel is provided with a disturbance device at its inlet. The hydrate-generating ring channel comprises N (N>1) stages, and N (N is an integer >1) stages of cyclone separators are provided on the hydrate-generating ring channel. The number of hydrate-generating ring channels and cyclone separators are equal and spaced apart. The inlet of the first-stage cyclone separator is connected to the outlet of the first-stage hydrate-generating ring channel. The first outlet of the Nn (n=1, 2…N-2, N-1)th stage cyclone separator is connected to the outlet of the N-n+1th stage (n=1, 2…N-… 2. The inlets of the tubular reaction loops of the N-1 stage are connected; the second outlet of the Nn (n=1, 2...N-2, N-1) stage hydrocyclones is connected to the inlet of the hydrate decomposition system (module); the first outlet of the N-1 stage hydrocyclone is connected to the membrane separation unit; the second outlet of the N-1 stage hydrocyclone is connected to the inlet of the hydrate decomposition system; the inlets of the Nm (m=0, 1, 2...N-2) tubular reaction loops are each independently connected to the first outlet of the hydrate decomposition system.

[0011] The hydrate decomposition system has a first outlet and a second outlet. The first outlet is connected to the water inlet unit and to the liquid inlet of the disturbance device.

[0012] The membrane separation unit is connected to the first outlet of the Nth stage cyclone separator and has a product gas outlet.

[0013] Furthermore, in the above technical solution, the hydrate-method combined membrane gas continuous separation system of the present invention further includes: a recovery unit, which is used to recover non-product gases from the membrane separation unit and the hydrate decomposition module.

[0014] Furthermore, in the above technical solution, the hydrate formation loop is a tubular reaction loop.

[0015] Furthermore, in the above technical solution, a ring temperature control system (i.e., a heat preservation device) is installed outside the hydrate generation ring. The ring control system is mainly used to provide the temperature of the ring pipe section. For example, a high-low temperature integrated bath can be used, with an operating temperature of -20~90℃, and it has overheat protection, overload protection, etc.

[0016] Furthermore, in the above technical solution, the hydrate formation annulus is equipped with an observation window, which has a pressure resistance greater than or equal to 20 MPa. The observation window is mainly used to observe the flow conditions and hydrate formation in the annulus system.

[0017] Furthermore, in the above technical solution, the hydrate generation loop is equipped with a quantitative injection module, which injects water and a promoter into the hydrate generation loop. The quantitative injection module is connected to the liquid outlet of the hydrate decomposition module.

[0018] Furthermore, in the above technical solution, the quantitative injection module includes a high-flow horizontal pump and a plunger pump.

[0019] Furthermore, in the above technical solution, the accelerator is tetrahydrofuran and / or tetrabutylammonium bromide.

[0020] Furthermore, in the above technical solution, the air inlet of the disturbance device is connected to the air intake unit, and an emergency discharge unit and a back pressure unit are provided between the air intake unit and the air inlet of the disturbance device.

[0021] Furthermore, in the above technical solution, the air intake unit can be a gas cylinder. When the pressure of the gas cylinder is insufficient, the gas cylinder is connected to the air intake of the disturbance device through a gas booster pump.

[0022] Furthermore, the disturbance device includes:

[0023] A mixing cylinder, which is equipped with a liquid inlet and a liquid outlet;

[0024] At least two cyclone mixers are evenly arranged circumferentially inside the mixing cylinder. The upper part of the cyclone mixer is provided with a tangential gas inlet, the lower part with a liquid inlet, and the upper center with an outlet.

[0025] The mixing pipe is connected to the outlet of the cyclone mixer. The mixing pipe includes: a central tube, which is a vertically arranged straight tube; multiple spiral tubes, which are arranged in multiple layers around the central tube, with the diameter of the multiple spiral tubes gradually increasing from the inner layer to the outer layer, and multiple sets of flow-blocking components arranged at intervals in each spiral tube; and an outer sleeve, which is fitted over the outermost spiral tube.

[0026] And a guide bend, which extends upward along the outer sleeve and then horizontally toward the axis of the mixing cylinder.

[0027] Furthermore, in the above technical solution, the two adjacent sets of flow-blocking components are spaced 1 / 4 of a spiral apart.

[0028] Furthermore, in the above technical solution, each group of flow-blocking components includes an even number of flow-blocking columns, and the axial direction of each flow-blocking column is arranged radially along the cross-section of the spiral tube, with the even number of flow-blocking columns symmetrically distributed on the cross-section of the spiral tube.

[0029] Furthermore, in the above technical solution, the cross-sectional shape of the flow-blocking column is circular, triangular, T-shaped, or trapezoidal.

[0030] Furthermore, in the above technical solution, the length of the flow-blocking column is 1 / 4 to 1 / 3 of the diameter of the corresponding spiral tube.

[0031] Furthermore, in the above technical solution, the width of the flow-blocking column is 0.1 to 0.3 times the diameter of the corresponding spiral tube.

[0032] Furthermore, in the above technical solution, the diameter of the outermost spiral tube is the same as the diameter of the central tube.

[0033] Furthermore, in the above technical solution, there is an even number of cyclone mixers.

[0034] Furthermore, in the above technical solution, the upper part of the cyclone mixer is provided with a spiral channel, which is connected to the gas inlet; the diameter of the outer sleeve of the mixing pipe is smaller than the outlet diameter of the cyclone mixer.

[0035] Furthermore, in the above technical solution, the liquid inlet of the cyclone mixer is connected to a liquid guide bend, and the liquid enters the liquid guide bend horizontally and then enters the cyclone mixer upward.

[0036] Furthermore, the cyclone mixer includes a conical cylinder, a straight cylinder connected to the upper edge of the conical cylinder, and a guide volute disposed on the upper edge of the straight cylinder; wherein, a gas inlet is constructed at the first end of the guide volute, and a mixed fluid outlet is constructed at the center of the guide volute.

[0037] The conical cylinder has an opening at its lower end, and the cyclone mixer also includes a guide bend, wherein the first end of the guide bend is connected to the opening, and the second end of the guide bend has a liquid inlet.

[0038] The conical cylinder and the straight cylinder together form the swirl mixer body. A mixing cylinder connected to the inner cavity of the swirl mixer body is provided at the upper end of the guide spiral tube. A mixing chamber is constructed inside the mixing cylinder. A mixing fluid outlet bend is provided at the upper end of the mixing pipe.

[0039] The inner diameter of the mixing pipe is smaller than the diameter of the outlet of the mixed fluid.

[0040] The mixing pipe consists of two straight pipes of different diameters forming a sleeve, within which spiral pipes of different diameters are arranged. The diameter of the spiral pipes gradually increases from the inside to the outside. When fluid flows through the spiral pipes, two vortices rotating in opposite directions are generated due to the pressure gradient imbalance perpendicular to the fluid flow direction and the effect of centrifugal force, creating secondary flow and forming Dean vortices. This causes changes in the velocity and pressure fields within the pipes. It is a type of accompanying flow occurring perpendicular to the main flow direction. The generation of Dean vortices increases the energy loss caused by resistance during fluid movement, improves the mass and heat transfer performance of the fluid, and enhances fluid mixing.

[0041] The hydrate formation loop is mainly used for hydrate production. The tubular reaction loop features a replaceable design, allowing for easy switching between different pipe diameters. Pipe pressure rating: 15MPa; operating temperature: -20~90℃; material: 316 stainless steel. All pipes are externally insulated to maintain a constant temperature.

[0042] Furthermore, cyclone separators are mainly used for gas-liquid separation of hydrates generated in tubular reaction loops.

[0043] Furthermore, the hydrate decomposition system is used to dissolve the generated hydrate slurry.

[0044] Furthermore, the membrane separation unit is used to further separate the generated lean gas.

[0045] Furthermore, the recovery unit is used to recover the loop system and the separated reaction gases to prevent environmental pollution. This system includes several shut-off valves and a gas booster pump.

[0046] Compared with the prior art, the present invention has one or more of the following beneficial effects:

[0047] 1. The gas-liquid separation system of the present invention includes a disturbance device that uses a multi-stage mixing mechanism consisting of a mixing cylinder, a cyclone mixer, a mixing pipe, and a guide bend. The fluid mixed by the cyclone mixer enters upward into the mixing pipe. The spiral tubes of different diameters in the mixing pipe not only enhance radial mixing but also generate Dean vortices, thus enhancing turbulence within the tube. A flow-blocking component is installed inside the spiral tube to separate the Dean vortices and form alternating reverse separation vortices, promoting gas-liquid contact mixing and increasing gas-liquid mass transfer. Multiple streams of fluid are ejected from the guide bend towards the center and impact each other, achieving extremely high relative velocities between phases at the moment of impact, strengthening interphase transfer, and thus improving the hydrate formation efficiency.

[0048] 2. The intensity of the Dean vortex in the helical tube is related to the inner diameter and helix diameter of the helical tube. In this invention, the diameter of the multiple helical tubes gradually increases from the inner layer to the outer layer, and the helix diameter also gradually increases from the inner layer to the outer layer. Therefore, the vortex intensity of the Dean vortex generated by helical tubes of different diameters is comparable, increasing the efficient mixing of the fluid. The medium flows through helical tubes of different diameters for different times, which to some extent increases the sub-mixing along the axial direction.

[0049] 3. The gas continuous separation system of the present invention, which combines hydrate method and membrane method, realizes the coupling of lean gas hydrate separation and rich gas membrane separation. It can make up for the problems of low separation efficiency of simple hydrate method for low concentration gas and the need for additional pressurization. The system of the present invention includes the entire process of generation, separation and dissolution, realizes continuous gas separation, and is easy to scale up and industrialize.

[0050] 4. By creating a hydrate generation loop, the gas-liquid contact residence time is increased, and the gas-liquid interface is renewed quickly, which is conducive to the continuous, efficient and rapid generation of hydrates.

[0051] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, and to make the above and other objects, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with reference to the accompanying drawings. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of a gas continuous separation system combining hydrate method and membrane method according to an embodiment of the present invention.

[0053] Figure 2 This is a top view of a hybrid pipeline according to an embodiment of the present invention.

[0054] Figure 3 This is a schematic diagram of the structure of a spiral tube according to an embodiment of the present invention.

[0055] Figure 4This is a schematic diagram of a cross-section of a spiral tube according to an embodiment of the present invention, showing a set of flow-blocking components on the cross-section.

[0056] Figure 5 This is a schematic diagram of the structure of a vortex mixer and mixing pipe according to an embodiment of the present invention.

[0057] Explanation of key figure labels:

[0058] 10-Gas cylinder, 11-Gas booster pump, 12-Emergency discharge unit, 13-Back pressure unit, 20-Disturbance device, 21-Mixing cylinder, 22-Swirl mixer, 221-Gas inlet, 222-Vortex channel, 223-Liquid guide bend, 224-Outlet, 23-Mixing pipe, 231-Central tube, 232-Spiral tube, 2321-Flow-blocking column, 233-Outer jacket, 24-Flow guide bend, 30-Hydrate generation loop, 31-Insulation device, 331-High-flow horizontal flow pump, 332-Water, 333-Plunger pump, 334-Accelerator, 40-Three-phase separator, 50-Hydrate decomposition module, 51-Magnetic circulation pump, 60-Membrane separation unit, 61-Product gas outlet, 70-Recovery unit. Detailed Implementation

[0059] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0060] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0061] In this document, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “upper,” etc., are used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” other elements or features will be oriented “above” the element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. Objects may also have other orientations (rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0062] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.

[0063] like Figure 1 As shown, the hydrate generation loop 30 includes N (N>1) stages, and N (N is an integer >1) stages of cyclone separators 40 are provided on the hydrate generation loop. The number of hydrate generation loops 30 and cyclone separators 40 is equal and they are arranged at intervals. The inlet of the first-stage cyclone separator is connected to the outlet of the first-stage hydrate generation loop. The first outlet of the Nn (n=1, 2...N-2, N-1)th stage cyclone separator is connected to the inlet of the N-n+1 (n=1, 2...N-2, N-1)th stage tubular reaction loop, and the second outlet of the Nn (n=1, 2...N-2, N-1)th stage cyclone separator is connected to the outlet of the tubular reaction loop. The inlet of the Nth stage hydrocyclone is connected to the inlet of the hydrate decomposition system (module); the first outlet of the Nth stage hydrocyclone is connected to the membrane separation unit 60; the second outlet of the Nth stage hydrocyclone is connected to the inlet of the hydrate decomposition system 50; the inlets of the Nm (m=0, 1, 2...N-2) tubular reaction loops are each independently connected to the first outlet of the hydrate decomposition system; the hydrate decomposition system 50 is provided with a first outlet and a second outlet, the first outlet is connected to the water inlet unit and to the liquid inlet of the agitation device; the inlet of the membrane separation unit is connected to the first outlet of the Nth stage hydrocyclone, and the membrane separation unit is provided with a product gas outlet 61.

[0064] Furthermore, in the above technical solution, the hydrate formation loop is a tubular reaction loop.

[0065] Furthermore, in the above technical solution, a heat preservation device is provided on the outside of the hydrate generation ring.

[0066] Furthermore, in the above technical solution, the hydrate formation ring is provided with an observation window, and the observation window has a pressure resistance greater than or equal to 20MPa.

[0067] Combination Figure 2-4As shown, the disturbance device 20 according to a specific embodiment of the present invention includes a mixing cylinder 21, at least two swirling mixers 22, a mixing pipe 23, and a guide bend 24. The mixing cylinder 21 is provided with a liquid inlet and a liquid outlet, and at least two swirling mixers 22 are uniformly arranged circumferentially inside the mixing cylinder 21. The swirling mixer 22 is provided with a tangential gas inlet 221 at the top, a liquid inlet at the bottom, and an outlet 224 at the center of the top. The mixing pipe 23 is connected to the outlet of the swirling mixer 22. In one or more embodiments of the present invention, the mixing pipe 23 includes, from the inside to the outside, a central tube 231, a plurality of spiral tubes 232, and an outer sleeve 233. The central tube 231 is a vertically arranged straight pipe, the plurality of spiral tubes 232 are arranged in multiple layers wound around the central tube 231, the diameter of the multiple spiral tubes 232 gradually increases from the inner layer to the outer layer, and the outer sleeve 233 is a straight pipe sleeved around the outermost spiral tube 232. Multiple sets of flow-blocking components are spaced apart inside each spiral tube 232. The flow-guiding bend 24 extends upward along the outer tube 233 and then extends horizontally toward the axis of the mixing cylinder 21. The fluid ejected from each flow-guiding bend 24 impacts each other, enhancing interphase transmission.

[0068] Furthermore, in one or more exemplary embodiments of the present invention, adjacent sets of flow-blocking components are spaced 1 / 4 of a helix apart, that is, a set of flow-blocking components is provided at every 90° rotation of the spiral tube 232. Furthermore, in one or more exemplary embodiments of the present invention, each set of flow-blocking components can consist of an even number of flow-blocking columns 2321, with the axial direction of each flow-blocking column 2321 arranged radially along the cross-section of the spiral tube 232, and the even number of flow-blocking columns 2321 in each set of flow-blocking components symmetrically distributed on the cross-section of the spiral tube 232. Figure 4In the illustrated embodiment, each set of flow-blocking components includes four flow-blocking columns 2321 uniformly distributed on the cross-section of the helical tube 232. Adjacent flow-blocking columns 2321 are spaced 90° apart; however, this invention is not limited to this. The flow-blocking columns 2321 are all positioned perpendicular to the flow direction of the main fluid in the helical tube 232. When fluid flows through the helical tube, due to the imbalance of the pressure gradient perpendicular to the flow direction and the effect of centrifugal force, two vortices with opposite rotation directions are generated, producing secondary flow and forming Dean vortices. The velocity and pressure fields within the helical tube change, resulting in a type of accompanying flow perpendicular to the main fluid direction. The generation of Dean vortices improves the mass and heat transfer performance of the fluid and enhances gas-liquid contact and mixing. The Dean number describes the relationship between centrifugal force and viscous force during fluid flow and can be used to characterize the intensity of Dean vortices. The Dean number is related to the diameter of the helical tube and the diameter of the spiral. The helical tube employs a design where the diameter gradually increases from the inside out, and the spiral diameter also gradually increases from the inside out. This ensures that the vortex intensity generated by the multi-layered helical tube is relatively uniform, promoting efficient fluid mixing. Symmetrically distributed flow-blocking columns within the helical tube separate the two Dean vortices generated within the tube, disrupting the disturbance of the Dean vortices on the fluid. Alternating counter-vortices, or separation vortices, are formed behind the flow-blocking columns. The separation effect of the flow-blocking columns, through redistribution, allows the fluid to achieve sufficient contact, further enhancing mixing. Subsequently, the fluid again forms Dean vortices due to the secondary flow within the helical tube, and then forms separation vortices again via the flow-blocking columns, repeating this process repeatedly through the helical tube. Gas-liquid mixtures with different turbulence intensities flow through the mixing pipe for different durations, thereby increasing sub-mixing along the axial direction.

[0069] Furthermore, in one or more exemplary embodiments of the present invention, the cross-sectional shape of the flow-blocking column 2321 is circular, triangular, T-shaped, or trapezoidal. It should be understood that the present invention is not limited thereto, and the shape of the flow-blocking column 2321 can be selected according to actual needs.

[0070] Further, in one or more exemplary embodiments of the present invention, the length of the flow-blocking column 2321 is 1 / 4 to 1 / 3 of the diameter of the corresponding spiral tube 232. Further, in one or more exemplary embodiments of the present invention, the width of the flow-blocking column 2321 is 0.1 to 0.3 times the diameter of the corresponding spiral tube 232. The width of the flow-blocking column 2321 refers to the width of the flow-facing surface; for example, when the flow-blocking column is a cylinder, its width is the diameter of the cylinder; when the flow-blocking column is a triangular prism, its width is the length of the base of the flow-facing surface.

[0071] Furthermore, in one or more exemplary embodiments of the present invention, the diameter of the outermost spiral tube 232 is the same as the diameter of the central tube 231.

[0072] Combination Figure 5As shown, in one or more exemplary embodiments of the present invention, there are an even number of cyclone mixers 22. In one or more exemplary embodiments of the present invention, a spiral channel 222 is provided on the upper part of the cyclone mixer 22, and the spiral channel 222 is connected to the gas inlet 221. Further, in one or more exemplary embodiments of the present invention, the liquid inlet of the cyclone mixer 22 is connected to the liquid guide bend 223, and the liquid enters the cyclone mixer 22 upward after entering the liquid guide bend 223 in the horizontal direction. The mixed gas enters the spiral channel 222 through the tangentially arranged gas inlet 221 of the cyclone mixer 22, and moves in a high-speed spiral motion from top to bottom along the inner wall of the cyclone mixer 22. A low-pressure zone is formed at the central axis of the cyclone mixer 22, which draws the liquid into the cyclone mixer 22 through the liquid inlet, and drives the fluid to contract and flow towards the center in the cyclone mixer 22, forming an upward secondary internal vortex flow that enters the mixing pipe 23 from the outlet of the cyclone mixer 22. For example, the diameter of the outer casing 233 of the mixing pipe 23 is smaller than the diameter of the outlet 224 of the swirl mixer 22. At the diameter change point, fluid friction and collision increase rapidly, resulting in local pressure loss and forming eddy current turbulence.

[0073] like Figure 1 As shown, in one or more embodiments of the present invention, the hydrate-membrane combined continuous gas separation system further includes a recovery unit 70, which is used to recover non-product gases from the membrane separation unit 60 and the hydrate decomposition system 50 to prevent environmental pollution.

[0074] Furthermore, in one or more exemplary embodiments of the present invention, the hydrate formation loop 30 can be a tubular reaction loop. Preferably, but not limitingly, the tubular reaction loop is designed to be replaceable, allowing for easy replacement between different pipe diameters. The pipe pressure is 15 MPa, and the operating temperature is -20 to 90°C. The tubular reaction loop can be made of 316 stainless steel, but the present invention is not limited thereto. Furthermore, in one or more exemplary embodiments of the present invention, the hydrate formation loop 30 is externally provided with a heat insulation device 32 to maintain a constant temperature. Exemplarily, the heat insulation device 32 can be a high-low temperature integrated bath, with an operating temperature of -20 to 90°C, and has functions such as overheat protection and overload protection. Furthermore, in one or more exemplary embodiments of the present invention, the hydrate formation loop 30 is provided with an observation window, the observation window having a pressure resistance greater than or equal to 20 MPa. The observation window is mainly used to observe the flow and hydrate formation in the hydrate formation loop 30.

[0075] Furthermore, in one or more exemplary embodiments of the present invention, the hydrate generation loop 30 is provided with a metering injection module. The metering injection module injects an accelerator 334 into the hydrate generation loop 30 through a plunger pump 333 and injects water 332 into the hydrate generation loop 30 through a high-flow horizontal pump 331. The metering injection module can be connected to the liquid outlet of the hydrate decomposition module 50 to realize the recycling of water in the system. It should be understood that the present invention is not limited thereto, and the specific type of pump used can be selected according to actual needs. Furthermore, in one or more exemplary embodiments of the present invention, the accelerator 333 can be tetrahydrofuran and / or tetrabutylammonium bromide, and the present invention is not limited thereto.

[0076] Furthermore, in one or more exemplary embodiments of the present invention, an emergency discharge unit 12 and a back pressure unit 13 are provided between the gas cylinder 10 of the air intake unit and the air inlet of the disturbance device 20.

[0077] Furthermore, in one or more exemplary embodiments of the present invention, when the pressure of the gas cylinder 10 is insufficient, the gas cylinder 10 is connected to the air inlet of the disturbance device 20 via the gas booster pump 11.

[0078] Example 1

[0079] The continuous gas separation system in this embodiment is as follows: Figures 1-5 As shown, its workflow is as follows:

[0080] The A / B mixed gas in cylinder 10 enters through the gas inlet 221 of the cyclone mixer. The A / B mixed gas then enters two cyclone mixers 22. The circulating liquid from the hydrate decomposition system is pumped into the mixing cylinder 21 through its first outlet via the magnetic circulation pump 51. The A / B mixed gas enters the cyclone mixer 22 tangentially at a certain velocity, undergoing a high-speed spiral motion from top to bottom along the inner wall. A low-pressure zone is formed at the central axis of the cyclone mixer 22, drawing the liquid in through the liquid inlet. This causes the fluid to contract and flow towards the center within the cyclone mixer 22, forming an upward secondary internal vortex that enters the mixing pipe 23 from the outlet of the cyclone mixer 22. The outer pipe 233 of the mixing pipe 23 has a smaller diameter than the outlet 224 of the cyclone mixer 22. At the diameter change point, fluid friction and collision increase rapidly, resulting in localized pressure loss and the formation of turbulent vortexes. The fluid, after being mixed through mixing pipe 23, is ejected from guide bend 24 and collides and mixes with each other in mixing cylinder 21. The mixed fluid falls into the liquid in mixing cylinder 21. During the circulation process, the liquid level in mixing cylinder 21 is higher than the liquid guide bend 223 of cyclone mixer 22. The fluid, after being mixed by agitation device 20, enters hydrate generation loop 30 to generate hydrates. The metering injection module meteringly replenishes water 332 and promoter 334 to agitation device 20 to ensure continuous circulation of the system. The A hydrate generated in hydrate generation loop 30, together with a portion of unreacted A / B mixed gas, enters the first-stage cyclone separator 40. After A hydrate and A / B mixed gas are separated in the first-stage hydrocyclone separator, the A / B mixed gas enters the next-stage hydrate generation loop 30 through the second outlet of the first-stage hydrocyclone separator 40. The gas from the Nth-stage hydrocyclone separator enters the membrane separation unit 60 through the first outlet. A hydrate and its slurry enter the hydrate decomposition module unit through the second outlet of the Nth-stage hydrocyclone separator. The A / B mixed gas containing a low concentration of A gas enters the membrane separation unit 60 for separation. The A gas enters the recovery unit 70 for recovery, and the B gas is discharged and collected through the product gas outlet 61 of the membrane separation unit 60. A hydrate and its slurry are decomposed into A gas and water or accelerator solution in the hydrate decomposition module 50. The A gas enters the recovery unit 70 for recovery, and the water or accelerator solution enters the metering injection module for recycling.

[0081] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. Any simple modifications, equivalent changes, and alterations made to the foregoing exemplary embodiments should fall within the scope of protection of the present invention.

Claims

1. A continuous gas separation system combining multi-stage hydrate method and membrane method, characterized in that, include: A hydrate generation loop is provided with a disturbance device at its inlet. The hydrate generation loop comprises N stages, each equipped with an N-stage cyclone separator. The number of hydrate generation loops and cyclone separators is equal and spaced apart. The inlet of the first-stage cyclone separator is connected to the outlet of the first-stage hydrate generation loop. The first outlet of the Nn-th stage cyclone separator is connected to the inlet of the (N-n+1)-th stage hydrate generation loop. The second outlet of the Nn-th stage cyclone separator is connected to the inlet of the hydrate decomposition module. The first outlet of the N-th stage cyclone separator is connected to the membrane separation unit. The second outlet of the N-th stage cyclone separator is connected to the inlet of the hydrate decomposition module. The inlets of each Nm-th stage hydrate generation loop are independently connected to the first outlet of the hydrate decomposition module. The hydrate decomposition module is provided with a first outlet and a second outlet. The first outlet is connected to the water inlet unit and to the liquid inlet of the disturbance device. A membrane separation unit is connected to the first outlet of the Nth stage cyclone separator, and the membrane separation unit is provided with a product gas outlet; Where N is an integer greater than 1, n = 1, 2, ..., N-2, N-1, m = 0, 1, 2, ..., N-2; The disturbance device includes a mixing cylinder having an inlet and an outlet. At least two cyclone mixers are evenly arranged circumferentially inside the mixing cylinder. The upper part of the cyclone mixer is provided with a tangential gas inlet, the lower part with a liquid inlet, and the upper center with an outlet. The mixing pipe is connected to the outlet of the cyclone mixer. The mixing pipe includes: a central tube, which is a vertically arranged straight tube; multiple spiral tubes, which are arranged in multiple layers around the central tube, with the diameter of the multiple spiral tubes gradually increasing from the inner layer to the outer layer, and multiple sets of flow-blocking components are arranged at intervals in each spiral tube; an outer sleeve, which is sleeved on the outermost spiral tube; and a flow-guiding bend, which extends upward along the outer sleeve and then extends horizontally toward the axis of the mixing cylinder.

2. The gas continuous separation system according to claim 1, characterized in that, The system also includes a recovery unit for recovering non-product gases from the membrane separation unit and the hydrate decomposition module.

3. The gas continuous separation system according to claim 1, characterized in that, The hydrate formation loop is a tubular reaction loop, and the outside of the hydrate formation loop is equipped with a heat preservation device.

4. The gas continuous separation system according to claim 1, characterized in that, The two adjacent sets of flow-blocking components are spaced 1 / 4 of a spiral apart.

5. The gas continuous separation system according to claim 1, characterized in that, Each set of flow-blocking components includes an even number of flow-blocking columns, with the axial direction of each flow-blocking column arranged radially along the cross-section of the helical tube. The even number of flow-blocking columns are symmetrically distributed on the cross-section of the helical tube.

6. The gas continuous separation system according to claim 5, characterized in that, The cross-sectional shape of the flow-blocking column can be circular, triangular, T-shaped, or trapezoidal.

7. The gas continuous separation system according to claim 5, characterized in that, The length of the flow-blocking column is 1 / 4 to 1 / 3 of the diameter of the corresponding spiral tube, and the width of the flow-blocking column is 0.1 to 0.3 times the diameter of the corresponding spiral tube.

8. The gas continuous separation system according to claim 1, characterized in that, The outermost spiral tube has the same diameter as the central tube.

9. The gas continuous separation system according to claim 1, characterized in that, The air inlet of the disturbance device is connected to the air intake unit, and an emergency discharge unit and a back pressure unit are provided between the air intake unit and the air inlet of the disturbance device.

10. The gas continuous separation system according to claim 1, characterized in that, The cyclone mixer has a spiral channel at the top, which is connected to the gas inlet; the outer tube of the mixing pipe has a smaller diameter than the outlet diameter of the cyclone mixer.

11. The gas continuous separation system according to claim 1, characterized in that, The liquid inlet of the cyclone mixer is connected to a liquid guide bend. The liquid enters the liquid guide bend horizontally and then enters the cyclone mixer upward.

12. The gas continuous separation system according to claim 1, characterized in that, The hydrate generation loop is equipped with a metering injection module, which injects water and a promoter into the hydrate generation loop. The metering injection module is connected to the liquid outlet of the hydrate decomposition module.

13. The gas continuous separation system according to claim 12, characterized in that, The quantitative injection module includes a high-flow horizontal pump and a plunger pump.

14. The gas continuous separation system according to claim 12, characterized in that, The accelerator is tetrahydrofuran and / or tetrabutylammonium bromide.

15. The gas continuous separation system according to claim 9, characterized in that, An emergency discharge unit and a back pressure unit are provided between the air intake unit and the gas inlet of the swirl mixer.

16. The gas continuous separation system according to claim 9, characterized in that, The air intake unit is a gas cylinder. When the pressure of the gas cylinder is insufficient, the gas cylinder is connected to the gas inlet of the cyclone mixer through a gas booster pump.

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