Differential type modular high gravity rotating packed bed and natural gas decarburization method

Abstract

The application discloses a differential type modular supergravity rotating packed bed and a natural gas decarburization method, and belongs to the technical field of supergravity rotating packed beds. The supergravity rotating packed bed comprises an outer shell, a horizontally rotatable rotor installed in the outer shell and a spraying pipe. A packing support frame, a packing cover plate and a plurality of layers of packing arranged in a ring are arranged on the rotor. The packing is fixedly arranged between the packing support frame and the packing cover plate. The packing rotates with the packing support frame. The rotating speeds of the layers of packing are different. The design solves the problem that liquid stays in the packed bed for a short time through a differential mechanism. The residence time of the reaction liquid in the packing is increased. More gas can be resolved or purer components can be refined under unit energy consumption. The total energy consumption of the system is reduced. Meanwhile, the modular design can only replace some modules with relatively serious corrosion during use of the supergravity rotating packed bed. The rotor rotating stability is improved. The production and operation cost of enterprises is also saved.

Description

Technical Field

[0001] This invention belongs to the field of ultragravity rotating packed bed technology, and in particular relates to a differential speed modular ultragravity rotating packed bed and a natural gas decarbonization method. Background Technology

[0002] There are various processing technologies and methods for decarbonizing natural gas, but existing decarbonization equipment suffers from problems such as large size and high cost, resulting in persistently high costs for processing carbon dioxide from natural gas. The high-gravity rotating packed bed is a mechanical device that enhances the reaction rate by strengthening multiphase flow transfer. It utilizes centrifugal force, much greater than gravity, generated by high-speed rotation, to cut the liquid flow into droplets of different sizes through the packing material. This expands the gas-liquid contact area, ensuring continuous contact between the two phases, enhancing mass transfer processes and efficiency, and reducing production costs.

[0003] However, for high-gravity rotating packed beds used in natural gas decarbonization processes, the liquid is highly corrosive. Once corrosion occurs, it affects the mass transfer process and efficiency, generating byproducts that affect the purity of the natural gas. Traditional high-gravity rotating packed beds require replacing the entire packing block, increasing production and operating costs. Furthermore, continuous high-speed rotation significantly reduces the residence time of the reaction liquid within the equipment, similarly affecting the mass transfer or chemical reaction process. Ultimately, this leads to insufficient mass transfer and incomplete reactions. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides a differential-speed modular high-gravity rotating packed bed and a natural gas decarbonization method, which can efficiently treat carbon dioxide present in natural gas to ensure processing efficiency. To achieve the above objectives, this invention adopts the following technical solution:

[0005] As a first aspect of the present invention, a differential modular high-gravity rotating packing bed is provided, comprising a shell, a horizontally rotatable rotor installed inside the shell, and a spray pipe. The rotor is provided with a packing support frame, a packing cover plate, and several layers of packing arranged in a ring. The packing is fixedly disposed between the packing support frame and the packing cover plate, and rotates with the packing support frame. Each layer of packing rotates at a different speed. The packing consists of at least two layers, and may have three or more layers.

[0006] Preferably, the packing material has three layers: an inner layer, a middle layer, and an outer layer. The packing support frame includes an inner layer support frame, a middle layer support frame, and an outer layer support frame. The packing cover plate includes an inner layer cover plate, a middle layer cover plate, and an outer layer cover plate. The inner layer support frame is located at the center, and the middle layer support frame and the outer layer support frame are arranged in a ring structure outwards.

[0007] Furthermore, it also includes a rotating shaft, which is fixedly connected to the outer end face of the inner support frame and connected to the drive mechanism;

[0008] The sun gear is connected to the shaft and fixed on the inner support frame;

[0009] The gear ring is fixed to the inner ring of the outer support frame, with the teeth facing the sun gear;

[0010] Planetary gears, at least two in number, are mounted on the middle support frame via a central axis and are arranged symmetrically about the axis of rotation.

[0011] Each planetary gear meshes with the sun gear and the ring gear, respectively.

[0012] Furthermore, a gas phase inlet is provided on the outer shell below the rotor, and a gas phase outlet is provided on the side of the outer shell. The spray pipe is installed inside the gas phase inlet and extends into the rotor. The inner end of the spray pipe is sealed, and spray holes are provided on the side wall. A liquid phase outlet is provided on the outer shell below the rotor.

[0013] Preferably, the inner layer packing, the middle layer packing, and the outer layer packing are all arc-shaped packing blocks spliced ​​together to form a ring.

[0014] Preferably, the inner end faces of the inner support frame, the middle support frame, and the outer support frame are respectively provided with support frame grooves, and the inner filler, the middle filler, and the outer filler are inserted into the support frame grooves to form a ring structure.

[0015] Preferably, the materials of the inner layer packing, the middle layer packing and the outer layer packing are selected from metal wire mesh, nickel foam, polytetrafluoroethylene and PP plastic; preferably, the inner layer packing is metal wire mesh, the middle layer packing is nickel foam and the outer layer packing is polytetrafluoroethylene.

[0016] Preferably, the pore size range of the inner packing is 4-8 mm, the pore size range of the middle packing is 3-6 mm, and the pore size range of the outer packing is 2-5 mm.

[0017] Preferably, the radius of the sun gear is in the range of 80-140mm, and the radius of the planet gear is in the range of 40-90mm.

[0018] In one embodiment, the middle layer packing consists of two layers: the inner middle layer packing is disposed on the inner support frame, and the outer middle layer packing is disposed on the middle support frame. The placement and number of layers can be expanded according to the product performance requirements.

[0019] As a second aspect of the present invention, a method for decarbonizing natural gas is provided, employing a differential modular high-gravity rotating packed bed provided by the present invention. Lean amine liquid enters through a spray pipe and is sprayed onto the inner circumferential surface of the inner packing layer via nozzles. Under centrifugal force, it flows from the inner packing layer to the middle and outer packing layers. The liquid is then thrown onto the outer shell by the rotor and discharged from the liquid phase outlet under gravity. Carbon-containing natural gas is introduced into the outer shell through the gas phase inlet and, under gas pressure, enters the inner, middle, and outer packing layers from the center of the rotor. It comes into countercurrent contact with the amine liquid and undergoes mass transfer. The purified natural gas leaves the rotor from the outer edge and is finally drawn out from the gas phase outlet.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] The advantages of this design lie in inheriting the high gas-side mass transfer efficiency of traditional packed beds while solving the problem of short liquid residence time within the packed bed through a differential mechanism. This increases the residence time of the reaction liquid in the packing, allowing for the extraction of more gas or the refinement of purer components per unit of energy consumption, thus reducing the overall energy consumption of the system. Furthermore, the modular design means that during the use of the high-gravity rotating packed bed, only severely corroded modules need to be replaced, facilitating balancing, improving rotor rotation stability, and saving on production and operating costs for the enterprise. Attached Figure Description

[0022] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0023] Figure 1 A cross-sectional view of the overall structure of the differential modular high-gravity rotating packing bed provided by the present invention.

[0024] Figure 2 This is a schematic diagram of the upper end face structure of the rotor in the differential modular high-gravity rotating packing bed provided by the present invention.

[0025] Figure 3 A schematic diagram of the packing structure in the differential modular high-gravity rotating packing bed provided by the present invention.

[0026] Figure 4 A schematic diagram of the outer shell structure in the differential modular high-gravity rotating packing bed provided by the present invention.

[0027] Figure 5 This is a schematic diagram of the lower end face structure of the support frame in the differential modular high-gravity rotating packing bed provided by the present invention.

[0028] Figure 6 This is a schematic diagram of the internal structure of the lower end face of the support frame in the differential modular high-gravity rotating packing bed provided by the present invention.

[0029] Figure 7 This is a schematic diagram of the spray pipe structure in the differential modular high-gravity rotating packing bed provided by the present invention.

[0030] Reference numerals: 1. Outer shell; 2. Gas phase inlet; 3. Gas phase outlet; 4. Liquid phase outlet; 5. Rotor; 6. Outer support frame; 7. Middle support frame; 8. Inner support frame; 9. Outer packing; 10. Middle packing; 11. Inner packing; 12. Bolt; 13. Outer packing cover plate; 14. Middle packing cover plate; 15. Inner packing cover plate; 16. Sun gear; 17. Planetary gears; 18. Gear ring; 19. Spray pipe; 20. Shaft; 21. Support frame groove; 22. Planetary gear bolt. Detailed Implementation

[0031] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0032] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] Example 1: A differential modular high-gravity rotating packing bed

[0034] like Figures 1-4As shown, the system includes a housing 1, a rotor 5, and a spray pipe 19 disposed inside the housing 1. The rotor 5 installed inside the housing 1 is horizontally rotatable. The rotor 5 includes an outer support frame 6, a gear ring 18 disposed on the outer support frame 6, a middle support frame 7, planetary gears 17, an inner support frame 8, a sun gear 16, an outer packing cover plate 13, a middle packing cover plate 14, an inner packing cover plate 15, an inner packing 11, a middle packing 10, and an outer packing 9. The outer support frame 6 is fixed to the housing 1 by welding. The inner support frame 8 is located at the center, with the middle support frame 7 and the outer support frame 6 arranged in a ring structure outwards. The outer end face of the inner support frame 8 is fixedly connected to a rotating shaft 20. The sun gear 16 is fixedly... The inner support frame 8 is fixed to the rotating shaft 20. The gear ring 18 is fixed to the inner ring of the outer support frame 6, with the tooth surface of the gear ring 18 facing the sun gear 16. There are 2-4 planetary gears 17, which are fixed to the middle support frame 7 by planetary gear bolts 22. The bottom surface of the bolt head of the planetary gear bolt 22 is 1-2mm away from the planetary gear 17 and should not be tightened. The contact position with the planetary gear 17 is the optical axis to ensure that the latter can rotate freely. The top surface of the planetary gear bolt 22 contacts the inner wall of the outer shell 1. The rotating shaft 20, which is fixed to the sun gear 16, can move axially. By adjusting the axial position of the rotating shaft 20 and the type and position of the planetary gear bolts 22, the planetary gears 17, gear ring 18 and sun gear 16 are kept on the same plane. The planetary gears 17 are symmetrically arranged with the rotating shaft 20 as the center. Each planetary gear 17 meshes with the sun gear 16 and gear ring 18 respectively. The rotating shaft 20 is connected to the motor drive shaft to provide driving force for the overall structure. A gas phase inlet 2 is machined on the outer casing 1 below the rotor, and a gas phase outlet 3 is machined on the side of the outer casing. The spray pipe 19 is installed inside the gas phase inlet 2 and extends into the rotor, with its bottom coinciding with the plane of the inner packing cover plate. Figure 7 As shown, the inner end of the spray pipe 19 is sealed, and spray holes are provided on the side wall. A liquid phase outlet 4 is machined on the outer shell below the rotor. The spray pipe 19, rotor 5, gas phase inlet 2, and outer shell 1 are located on the same straight line.

[0035] The outer support frame 6, the middle support frame 7 and the inner support frame 8 are respectively connected to the outer packing cover plate 13, the middle packing cover plate 14 and the inner packing cover plate 15 by bolts 12, forming a space to accommodate the outer packing 9, the middle packing 10 and the inner packing 11.

[0036] As one implementation method, such as Figure 3 and Figure 5 As shown, the outer packing cover plate 13, the middle packing cover plate 14, and the inner packing cover plate 15 are fixedly connected to the outer support frame 6, the middle support frame 7, and the inner support frame 8, respectively. The outer packing 9 is encapsulated between the outer packing cover plate 13 and the outer support frame 6, the middle packing 10 is encapsulated between the middle packing cover plate 14 and the middle support frame 7, and the inner packing 11 is encapsulated between the inner packing cover plate 15 and the inner support frame 8.

[0037] like Figure 6 As shown, the inner end faces of the inner support frame 8, the middle support frame 7, and the outer support frame 6 are respectively provided with support frame grooves 21, such as... Figure 3 As shown, the inner layer packing 11, the middle layer packing 10, and the outer layer packing 9 are all arc-shaped packing blocks. The inner layer packing 11, the middle layer packing 10, and the outer layer packing 9 are inserted into the support frame groove 21 to form a ring structure, and are fixed by corresponding layer cover plates. The cover plates are bolted to the corresponding support frame. The inner layer packing, the middle layer packing, and the outer layer packing can use the same or different types of packing.

[0038] The intermediate layer filler can be one or more layers. As a typical implementation scheme, for example... Figure 3 As shown, the inner packing 11 consists of two layers. The two inner packing layers are set on the inner support frame 8, and the middle packing 10 is set on the middle support frame 7. The setting position and number of layers can be expanded according to the product performance requirements.

[0039] The inner, middle, and outer packing layers can be made of materials commonly used in the field, including metal wire mesh, nickel foam, polytetrafluoroethylene (PTFE), and PP plastic. Typically, the inner packing layer uses metal wire mesh to cut the continuous liquid flow into fine filaments and droplets; the middle packing layer uses nickel foam to increase the residence time of the reaction liquid within the packing, promoting the continuous progress of the reaction; and the outer packing layer uses PTFE, which helps to transform the filaments and droplets of the reaction liquid ejected from the nickel foam into a liquid film, increasing the contact area for the gas-liquid reaction and improving reaction efficiency. Other materials with the above-mentioned effects can also be selected.

[0040] The inner layer packing has a pore size range of 4-8 mm, the middle layer packing has a pore size range of 3-6 mm, and the outer layer packing has a pore size range of 2-5 mm. The structural diagram is for illustrative purposes only and does not specify the pore size ratio between the different layers of packing.

[0041] As a typical example, the radius of the sun gear ranges from 80 to 140 mm, and the radius of the planet gears ranges from 40 to 90 mm.

[0042] The motor drives the rotating shaft 20 and the sun gear 16 to rotate. The sun gear 16 is connected to the inner support frame 8, thereby causing the inner packing 11 to rotate. The sun gear 16 drives the planetary gears 17 to rotate around the sun gear 16, thereby causing the middle support frame 7 to drive the middle packing 10 to rotate, at a speed lower than that of the inner packing. The planetary gears 17 transmit power to the gear ring 18, causing the gear ring 18 to rotate. The gear ring 18 is connected to the outer support frame 6, and the outer support frame 6 drives the outer packing 9 to rotate, at a speed lower than that of the middle packing 10.

[0043] Example 2, a method for decarbonizing natural gas

[0044] Natural gas decarbonization is performed using a mixed solution of ethanolamine (MEA), diethanolamine (MDEA), and water. The lean amine solution enters through spray pipe 19 and is sprayed onto the inner circumferential surface of the inner packing layer 11 via nozzles. Under centrifugal force, it flows from the inner packing layer 11 to the middle packing layer 10 and the outer packing layer 9. During this process, the liquid is dispersed, cut, and broken by the enormous shear force of the packing, forming liquid filaments, liquid films, and droplets—states that cannot be formed under conventional operating conditions. The surface area of ​​the liquid is extremely large and constantly renewed. The rotational speed gradually decreases from the inner packing layer to the middle packing layer and then to the outer packing layer, increasing the residence time of the reaction droplets in the rotor and consequently increasing the reaction time between the reaction liquid and the carbon-containing natural gas, creating excellent mass transfer and reaction conditions inside the rotor. The liquid is then thrown to the outer shell by the rotor and discharged from the liquid phase outlet 4 under gravity, being transported to the regeneration equipment for desorption. This process prolongs the residence time of the liquid in the packed bed, increases the carbon dioxide loading of the amine solution, and allows for the desorption of more carbon dioxide gas per unit of energy consumption in the subsequent heating and desorption stage, thus reducing the overall energy consumption of the system. Carbonaceous natural gas is introduced into the outer cavity of the supergravity machine through gas phase inlet 2. Under the action of gas pressure, it enters the inner packing 11, middle packing 10 and outer packing 9 from the center of the rotor. It comes into countercurrent contact with the amine liquid and undergoes mass transfer. The purified natural gas leaves the rotor from the outer edge and is finally led out through gas phase outlet 2.

[0045] As a typical embodiment, a rotating packed bed with the following structure is provided:

[0046] The sun gear has a radius of 105mm, the planet gear has a radius of 65.3mm, and the inner, middle and outer packing materials are metal wire mesh, nickel foam and polytetrafluoroethylene, respectively. The pore sizes of the four packing layers are 4-8mm, 4-8mm, 3-6mm and 2-5mm from the inside to the outside.

[0047] The shaft speed is 500 rpm.

[0048] Natural gas decarbonization was performed using the steps described in Example 2. The results showed that the desorption reaction time was less than 2 seconds, the desorption rate was over 95%, and the carbon dioxide content of the natural gas was 0.44%. The device used for natural gas decarbonization achieved a high desorption rate and higher purity.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A differential-speed modular high-gravity rotating packing bed, characterized in that, It includes an outer shell, a horizontally rotatable rotor installed inside the outer shell, and a spray pipe. The rotor is provided with a packing support frame, a packing cover plate, and several layers of packing arranged in a ring. The packing is fixedly installed between the packing support frame and the packing cover plate. The packing rotates with the packing support frame, and the rotation speed of each layer of packing is different. The packing consists of three layers: an inner layer, a middle layer, and an outer layer. The packing support frame includes an inner layer support frame, a middle layer support frame, and an outer layer support frame. The packing cover plate includes an inner layer cover plate, a middle layer cover plate, and an outer layer cover plate. The inner layer support frame is located at the center, and the middle layer support frame and the outer layer support frame are arranged in a ring structure outwards. It also includes a rotating shaft, which is fixedly connected to the outer end face of the inner support frame and connected to the drive mechanism; The sun gear is connected to the shaft and fixed on the inner support frame; The gear ring is fixed to the inner ring of the outer support frame, with the teeth facing the sun gear; Planetary gears, at least two in number, are mounted on the middle support frame via a central axis and are arranged symmetrically about the axis of rotation. Each planetary gear meshes with the sun gear and the ring gear, respectively.

2. The differential modular high-gravity rotating packing bed according to claim 1, characterized in that, The inner layer packing, middle layer packing, and outer layer packing are all arc-shaped packing blocks, spliced ​​together to form a ring.

3. The differential modular high-gravity rotating packing bed according to claim 1, characterized in that, The inner end faces of the inner support frame, the middle support frame, and the outer support frame are respectively provided with support frame grooves. The inner filler, the middle filler, and the outer filler are inserted into the support frame grooves to form a ring structure.

4. The differential modular high-gravity rotating packing bed according to claim 1, characterized in that, A gas phase inlet is provided on the outer casing below the rotor, and a gas phase outlet is provided on the side of the outer casing. The spray pipe is installed in the gas phase inlet and extends into the rotor. The inner end of the spray pipe is sealed, and spray holes are provided on the side wall. A liquid phase outlet is provided on the outer casing below the rotor.

5. The differential modular high-gravity rotating packing bed according to claim 1, characterized in that, The materials for the inner, middle, and outer packing layers are selected from metal wire mesh, nickel foam, polytetrafluoroethylene, and PP plastic.

6. The differential modular high-gravity rotating packing bed according to claim 1, characterized in that, The inner layer packing has a pore size range of 4-8 mm, the middle layer packing has a pore size range of 3-6 mm, and the outer layer packing has a pore size range of 2-5 mm.

7. The differential modular high-gravity rotating packing bed according to claim 1, characterized in that, The radius of the sun gear ranges from 80 to 140 mm, and the radius of the planet gears ranges from 40 to 90 mm.

8. A method for decarbonizing natural gas, characterized in that, The differential modular high-gravity rotating packed bed as described in any one of claims 1 to 7 is used. The lean amine liquid enters through a spray pipe, the inner end of which is sealed. Spray holes are provided on the sidewall, and the lean amine liquid is sprayed onto the inner circumferential surface of the inner packing layer through these holes. Under centrifugal force, the liquid flows from the inner packing layer to the middle and outer packing layers. Then, the liquid is thrown onto the outer shell by the rotor and discharged from the liquid phase outlet under gravity. Carbon-containing natural gas is introduced into the outer shell through the gas phase inlet and enters the inner, middle, and outer packing layers from the center of the rotor under gas pressure. It comes into countercurrent contact with the amine liquid and undergoes mass transfer. The purified natural gas leaves the rotor from the outer edge and is finally drawn out from the gas phase outlet.

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