A hydrate production column and method

Abstract

The application provides a hydrate generating tower, and belongs to the technical field of gas separation by hydrate generation method.The hydrate generating tower comprises a synthesis tower barrel;an inner coil is arranged in the synthesis tower barrel;an agitator, a gas phase discharge port and a liquid phase discharge port are arranged at the top of the synthesis tower barrel, and the gas phase discharge port is located above the liquid phase discharge port;and a liquid phase feed port and a gas phase feed port are arranged at the lower part of the synthesis tower barrel, and the liquid phase feed port is located above the gas phase feed port.The application realizes continuous feeding of the gas phase and the liquid phase and continuous discharge of the hydrate product, and realizes separation of the hydrate and the gas phase in the synthesis tower;uniform mixing of the gas phase and the liquid phase raw materials is realized, the phenomenon of hydrate gathering to the wall surface in the hydrate formation process is eliminated, and continuous generation of the solid hydrate is realized;by arranging the agitator and the inner coil, the "wall climbing" phenomenon in the hydrate generation process is reduced, and enrichment of the hydrate solid on the inner wall or the surface of the inner member is effectively prevented.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of hydrate formation method for separating gas, and particularly relates to a hydrate formation tower and method in a hydrate formation method for separating gas. BACKGROUND

[0002] Gas separation is an important chemical process, which usually needs to separate single component from multi-component gas, and is widely used in the treatment of natural gas, coke oven gas, water gas, ammonia synthesis purge gas, cracking gas, refinery dry gas, etc. In the gas separation industry, how to efficiently and lowly separate mixed gas has become a key research direction of the chemical industry.

[0003] For the mixed gas with high separation difficulty, the main separation technologies reported at present include pressure swing adsorption, cryogenic separation, absorption method, membrane separation method, etc. The pressure swing adsorption separation method is a process for separating gas by periodically changing the operating pressure of the adsorption bed, based on the characteristics that the adsorption characteristics of different gas components in the solid adsorbent change with the pressure. The cryogenic separation method is a method for separating components by rectification based on the different relative volatility of each component in the liquefied mixture at low temperature. The oil absorption method is a method for separating components by absorption and desorption based on the different solubility of different components in the absorbent. The membrane separation method is a new separation method for separating components by using membrane as a selective barrier layer based on the different permeation rates of each component through the membrane.

[0004] The hydrate formation method for separating gas has been greatly developed in recent years as a potential energy-saving separation technology. Hammerschimdt discovered in 1934 that selective separation of gas can be achieved in the hydrate formation process. Subsequently, people systematically studied the hydrate formation conditions of single-component gas, and found that different gases have different hydrate formation conditions. Based on this difference, different hydrates can be formed at different pressures and temperatures to achieve the purpose of separating gas, so that the easily hydrating substances are enriched in the hydrate, and the difficultly hydrating substances are enriched in the equilibrium gas.

[0005] Currently, gas separation technology using hydrate formation has not yet been industrialized, primarily due to the difficulty in achieving continuous and rapid hydrate formation. The formation of gas hydrates involves the conversion of gas and liquid into solid products. According to the two-film theory, the formed solid hydrate exists between the gas and liquid phases. The dense hydrate hinders further contact between the two phases, resulting in significant mass transfer resistance between the gas and liquid films, thus hindering further hydrate formation. Furthermore, the formation of hydrates within the equipment inevitably involves a "wall-climbing" phenomenon, where hydrates tend to accumulate on the cold solid walls, severely impacting continuous hydrate formation. Current methods for hydrate formation include using mechanical methods such as stirring, bubbling, and spraying to increase the formation rate and reduce "wall-climbing," adding hydraulic or thermodynamic promoters to reduce interfacial resistance, and using fixed porous media beds to increase the interfacial contact area.

[0006] Currently, there are few designs for synthesis towers in hydrate generation gas separation technology, and "wall climbing" is prone to occur in hydrate synthesis towers, which seriously affects the continuous operation of the synthesis tower and hinders the industrialization of hydrate generation gas separation technology.

[0007] Therefore, there is an urgent need to develop a hydrate generation tower that can be operated continuously and has good stability. Summary of the Invention

[0008] The purpose of this invention is to solve the problems existing in the prior art and provide a hydrate generation tower and method, which solves the "wall climbing" problem in the hydrate generation process of the prior art, eliminates the phenomenon of hydrate gathering on the wall surface during the formation process, and realizes the continuous formation of solid hydrates.

[0009] This invention is achieved through the following technical solution:

[0010] In a first aspect, the present invention provides a hydrate generation tower, comprising a synthesis tower body;

[0011] The synthesis tower body is equipped with an inner coil, which is located in the lower middle part of the synthesis tower body.

[0012] The top of the synthesis tower is equipped with a stirrer, a gas phase outlet and a liquid phase outlet, and the gas phase outlet is located above the liquid phase outlet;

[0013] The lower part of the synthesis tower is provided with a liquid phase inlet and a gas phase inlet.

[0014] A further improvement of the present invention is that:

[0015] The stirring rod of the stirrer extends into the synthesis tower body;

[0016] The stirring rod is connected with a double helical stirring paddle.

[0017] The further improvement of the present application is that:

[0018] The inner coil is a cylinder structure formed by helically winding the cooling pipe.

[0019] The inner coil inlet and the inner coil outlet both extend out of the synthesis tower cylinder.

[0020] The further improvement of the present application is that:

[0021] The double helical stirring paddle is located in the inner coil.

[0022] The distance between the outer side wall of the double helical stirring paddle and the inner side wall of the inner coil is not more than 3 times the diameter of the cooling pipe.

[0023] The further improvement of the present application is that:

[0024] A liquid phase feeding pipe is sealingly arranged at the liquid phase feeding port, and a gas phase feeding pipe is sealingly arranged at the gas phase feeding port.

[0025] The liquid phase feeding pipe and the gas phase feeding pipe both extend into the synthesis tower cylinder.

[0026] The further improvement of the present application is that:

[0027] The part of the liquid phase feeding pipe and the gas phase feeding pipe located in the synthesis tower cylinder is respectively provided with a plurality of expansion openings.

[0028] The further improvement of the present application is that:

[0029] The expansion openings are all arranged on the bottom surface of the part of the liquid phase feeding pipe and the gas phase feeding pipe located in the synthesis tower cylinder.

[0030] The further improvement of the present application is that:

[0031] The part of the liquid phase feeding pipe and the gas phase feeding pipe located in the synthesis tower cylinder is a disc, a straight cylinder pipe, a cross-shaped straight cylinder pipe or a three straight cylinder pipe cross structure.

[0032] The further improvement of the present application is that:

[0033] A defoamer is arranged at the upper end inside the synthesis tower cylinder.

[0034] The defoamer is located between the gas phase discharge port and the liquid phase discharge port.

[0035] In a second aspect, the present application provides a method for generating hydrates, which comprises the following steps:

[0036] The cold medium below the hydrate formation temperature is continuously fed into the inner coil, the stirrer is turned on to continuously stir, the liquid phase feed required for forming hydrate is continuously released from the liquid phase feed pipe, the gas phase feed required for forming hydrate is continuously released from the gas phase feed pipe, and the mixed gas-liquid phase reactants move upwards in the synthesis tower barrel, and solid hydrate is gradually formed in the synthesis tower barrel due to the cooling of the inner coil;

[0037] Meanwhile, the continuous destruction of the gas-liquid phase interface by the screw ribbon stirring paddle and the prevention of the growth of hydrate to the inner coil and the inner wall thereof make the formed solid hydrate reach the upper part of the synthesis tower barrel together with the gas-liquid phase and be separated;

[0038] The unreacted gas phase is continuously discharged through the gas phase discharge port, and the mixture of solid hydrate and liquid phase is continuously discharged from the liquid phase discharge port.

[0039] Compared with the prior art, the hydrate synthesis tower has the following beneficial effects:

[0040] The hydrate synthesis tower realizes the continuous feeding of the gas phase and the liquid phase and the continuous discharge of the hydrate product, and realizes the separation of the hydrate and the gas phase in the synthesis tower at the same time. Meanwhile, the hydrate synthesis tower reduces the "wall climbing" phenomenon in the hydrate generation process by arranging the stirrer and the inner coil, and effectively prevents the enrichment of the hydrate solid on the inner wall or the surface of the inner member.

[0041] The hydrate synthesis tower realizes the uniform mixing of the gas phase and the liquid phase raw materials, eliminates the phenomenon of wall gathering during the hydrate formation process, and realizes the continuous generation of solid hydrate. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 is a structural schematic view of the hydrate synthesis tower of the present application;

[0043] Figure 2 is a first kind of structural schematic view of the part of the liquid phase feed pipe and the gas phase feed pipe in the synthesis tower barrel;

[0044] Figure 3 is a second kind of structural schematic view of the part of the liquid phase feed pipe and the gas phase feed pipe in the synthesis tower barrel;

[0045] Figure 4 is a third kind of structural schematic view of the part of the liquid phase feed pipe and the gas phase feed pipe in the synthesis tower barrel;

[0046] Figure 5 is a fourth kind of structural schematic view of the part of the liquid phase feed pipe and the gas phase feed pipe in the synthesis tower barrel.

[0047] In the figure, 1, agitator, 2, liquid phase discharge port, 3, stirring paddle, 4, inner coil, 5, gas phase feed pipe, 6, liquid phase feed pipe, 7, inner coil outlet, 8, inner coil inlet, 9, synthesis tower barrel, 10, gas phase discharge port, 11, defoamer. DETAILED DESCRIPTION

[0048] The application will be described in further detail below with reference to the drawings:

[0049] The application provides a hydrate synthesis tower, and embodiments of the hydrate synthesis tower are as follows:

[0050]

Example 1

[0051] As shown in the figure, the hydrate synthesis tower comprises a synthesis tower barrel 9, and the axial direction of the synthesis tower barrel 9 is defined as the height direction; Figure 1

[0052] The synthesis tower barrel 9 is internally provided with an inner coil 4, and the inner coil 4 is located at the middle lower part of the synthesis tower barrel 9.

[0053] The synthesis tower barrel 9 is provided at the top with an agitator 1, a gas phase discharge port 10 and a liquid phase discharge port 2, and the gas phase discharge port 10 is located above the liquid phase discharge port 2.

[0054] The synthesis tower barrel 9 is provided at the lower part with a liquid phase feed port and a gas phase feed port, and the liquid phase feed port is located above the gas phase feed port.

[0055] The stirring rod of the agitator 1 extends into the synthesis tower barrel 9, and a double helical ribbon stirring paddle 3 is connected to the stirring rod, and the double helical ribbon stirring paddle 3 generates upward kinetic energy for the material when rotating, reduces the settlement of solid hydrates, and reduces the generation of the “wall climbing” phenomenon in the hydrate synthesis process.

[0056] The inner coil 4 is a barrel structure formed by spirally winding a cooling pipe, and the inner coil inlet 8 and the inner coil outlet 7 both extend out of the synthesis tower barrel 9. The cooling medium continuously enters the inner coil 4 from the inner coil inlet 8 to cool the substances in the synthesis tower barrel 9, and the cooling medium is finally discharged through the inner coil outlet 7.

[0057] The double helical ribbon stirring paddle 3 is located in the inner coil 4, and the distance between the outer side wall of the double helical ribbon stirring paddle 3 and the inner side wall of the inner coil 4 is not more than 3 times the diameter of the cooling pipe, so as to reduce the short circuit flow of the raw material mixture in the gap, reduce the generation of the “wall climbing” phenomenon in the hydrate synthesis process, and effectively prevent the enrichment of hydrate solids on the inner wall or the surface of the inner member.

[0058] ​During the operation of the hydrate formation tower, the inner coil 4 is continuously fed with cold medium below the hydrate formation temperature through the inner coil inlet 8, the cold medium flows out through the inner coil outlet 7 after passing through the inner coil 4, the stirrer 1 is continuously operated to stir, the liquid phase feed required for hydrate formation is continuously released through the liquid phase feed inlet, the gas phase feed required for hydrate formation is continuously released through the gas phase feed inlet, and the mixed gas-liquid phase reactants move upwards in the synthesis tower barrel 9, and solid hydrates are gradually formed in the synthesis tower barrel 9 due to the cooling of the inner coil 4; at the same time, the screw belt stirring paddle 3 continuously breaks the gas-liquid phase interface and prevents the hydrates from gathering and growing towards the inner coil and its inner wall, so that the formed solid hydrates reach the upper part of the synthesis tower barrel together with the gas-liquid phase and are separated; the unreacted gas phase is continuously discharged through the gas phase outlet 10, and the mixture of solid hydrates and liquid phase is continuously discharged from the liquid phase outlet 2.

[0059]

Example 2

[0060] The liquid phase feed inlet is sealingly provided with a liquid phase feed pipe 6, and the gas phase feed inlet is sealingly provided with a gas phase feed pipe 5, both the liquid phase feed pipe 6 and the gas phase feed pipe 5 extend into the synthesis tower barrel 9, and the portions of the liquid phase feed pipe 6 and the gas phase feed pipe 5 located in the synthesis tower barrel 9 meet the requirement that the liquid phase flowing out of the liquid phase feed pipe can mix with the gas phase flowing out of the gas phase feed pipe.

[0061] As shown in Figures 2 to 5 , the portions of the liquid phase feed pipe 6 and the gas phase feed pipe 5 located in the synthesis tower barrel 9 are respectively provided with a plurality of expansion openings, the plurality of expansion openings increase the release area of the gas phase and liquid phase raw materials, so that the phase interface when the gas-liquid phase contacts is larger, the uniform mixing of the gas phase and liquid phase raw materials is realized, the phenomenon of hydrate gathering to the wall surface during the hydrate formation process is eliminated, and the continuous generation of solid hydrates is realized.

[0062] Preferably, the expansion openings are all arranged on the bottom surface of the portions of the liquid phase feed pipe 6 and the gas phase feed pipe 5 located in the synthesis tower barrel 9, and the downward opening of the expansion openings can reduce the disturbance of the gas phase and liquid phase feed to the flow in the synthesis tower barrel, and increase the residence time of the gas phase and liquid phase raw materials in the synthesis tower barrel, which is beneficial to the formation of hydrates.

[0063] The portions of the liquid phase feed pipe 6 and the gas phase feed pipe 5 located in the synthesis tower barrel 9 can all be disc-shaped (as shown in Figure 5 ), straight cylinder pipe-shaped (as shown in Figure 2 ), cross-shaped straight cylinder pipe-shaped (as shown in Figure 3 ) or three straight cylinder pipe cross-shaped structure (as shown in Figure 4 ).

[0064] The structure of the part of the liquid phase feeding pipe 6 and the gas phase feeding pipe 5 in the synthesis tower barrel 9 can be the same or different, and is preferably the same, so that the contact forms of the gas phase and the liquid phase into the barrel are basically the same.

[0065] Example 3

[0066] The upper end of the inside of the synthesis tower barrel 9 is provided with a demister 11, and the demister 11 is located between the gas phase discharge port 10 and the liquid phase discharge port 2. The position above the liquid phase discharge port 2 is a gas phase space for separating the gas phase that does not form hydrates. The demister 11 can reduce the liquid substances entrained in the gas phase, and improve the gas separation efficiency in the hydrate formation process.

[0067] The demister 11 is a prior device, and will not be described here.

[0068] The hydrate synthesis tower of the present application realizes continuous feeding of the gas phase and the liquid phase and continuous discharge of the hydrate product, and realizes separation of the hydrate and the gas phase in the synthesis tower at the same time. At the same time, the hydrate synthesis tower reduces the "wall climbing" phenomenon in the hydrate formation process by setting the stirrer and the inner coil, and effectively prevents the enrichment of the hydrate solid on the inner wall or the surface of the inner member.

[0069] The hydrate synthesis tower of the present application realizes uniform mixing of the gas phase and the liquid phase raw materials, eliminates the phenomenon of wall gathering in the hydrate formation process, and realizes continuous generation of the solid hydrate.

[0070] The present application also provides a hydrate generation method, which generates hydrates by using the above-mentioned hydrate synthesis tower. The implementation of the method is as follows:

[0071] Example 4

[0072] The method specifically comprises the following steps:

[0073] The low-temperature medium is continuously fed into the inner coil 4 below the hydrate formation temperature, the stirrer 1 is continuously started to stir, the liquid phase feeding pipe 6 continuously releases the liquid phase feeding required for hydrate formation, the gas phase feeding pipe 5 continuously releases the gas phase feeding required for hydrate formation, and the mixed gas-liquid phase reactants move upwards in the synthesis tower barrel 9. Due to the cooling of the inner coil 4, the solid hydrate is gradually formed in the synthesis tower barrel 9;

[0074] At the same time, the spiral ribbon stirrer 3 continuously destroys the gas-liquid phase interface and prevents the hydrate from gathering and growing to the inner coil 4 and the inner wall thereof, so that the formed solid hydrate reaches the upper part of the synthesis tower barrel 9 together with the gas-liquid phase and is separated;

[0075] The unreacted gas phase is continuously discharged through the gas phase discharge port 10, and the mixture of the solid hydrate and the liquid phase is continuously discharged from the liquid phase discharge port 2.

[0076] The hydrate generation method realizes continuous feeding of gas phase and liquid phase and continuous discharge of hydrate product, and realizes separation of hydrate and gas phase inside the synthesis tower; meanwhile, the hydrate synthesis tower is provided with a stirrer and an inner coil, and the screw stirring paddle 3 continuously breaks the gas-liquid phase interface and prevents the hydrate from gathering and growing to the inner coil and the inner wall thereof, reduces the wall-climbing phenomenon in the hydrate generation process, and effectively prevents enrichment of hydrate solids on the inner wall or the surface of inner members.

[0077] The hydrate generation method realizes uniform mixing of gas phase and liquid phase raw materials, eliminates the phenomenon of wall gathering in the hydrate formation process, and realizes continuous generation of solid hydrate.

[0078] In the description of the present application, it should be noted that unless otherwise specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0079] In the description of the present application, unless otherwise stated, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the present application.

[0080] Finally, it should be noted that the above technical solutions are only one embodiment of the present application, and for those skilled in the art, on the basis of the application disclosed in the present application and the application method and principle, various types of improvements or modifications can be easily made, and are not limited to the methods described in the above embodiment of the present application, therefore the above description is only preferred, and does not have a limiting meaning.

Claims

1. A hydrate production column characterized by, The synthetic tower barrel comprises a barrel body; An inner coil is arranged inside the barrel body, and the inner coil is located in the middle and lower part of the barrel body and has a barrel structure formed by spirally winding a cooling pipe; A stirrer, a gas phase discharge port and a liquid phase discharge port are arranged at the top of the barrel body, the gas phase discharge port is located above the liquid phase discharge port, the stirring rod of the stirrer extends into the barrel body, a double-screw stirring paddle is connected to the stirring rod, the double-screw stirring paddle is located in the inner coil, and the distance between the outer side wall of the double-screw stirring paddle and the inner side wall of the inner coil is not more than 3 times the diameter of the cooling pipe; A liquid phase feed port and a gas phase feed port are arranged at the lower part of the barrel body, a liquid phase feed pipe is sealingly arranged at the liquid phase feed port, a gas phase feed pipe is sealingly arranged at the gas phase feed port, the liquid phase feed pipe and the gas phase feed pipe both extend into the barrel body, and the portions of the liquid phase feed pipe and the gas phase feed pipe located in the barrel body are respectively provided with a plurality of expansion ports.

2. The hydrate formation tower of claim 1, wherein, The inlet and outlet of the inner coil both extend out of the barrel body.

3. The hydrate formation tower of claim 1, wherein, The expansion ports are arranged on the bottom surface of the portions of the liquid phase feed pipe and the gas phase feed pipe located in the barrel body.

4. The hydrate formation tower of claim 3, wherein, The portions of the liquid phase feed pipe and the gas phase feed pipe located in the barrel body are disc-shaped, straight tube-shaped, cross-shaped straight tube-shaped or three straight tube-shaped cross-shaped structures.

5. The hydrate formation tower of claim 4, wherein, A defoamer is arranged at the upper end of the barrel body, and the defoamer is located between the gas phase discharge port and the liquid phase discharge port.

6. A method for hydrate formation using the hydrate formation column according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: A cooling medium with a temperature lower than the hydrate formation temperature is continuously fed into the inner coil, the stirrer is turned on to continuously stir, the liquid phase feed required for hydrate formation is continuously released from the liquid phase feed pipe, the gas phase feed required for hydrate formation is continuously released from the gas phase feed pipe, the mixed gas-liquid phase reactants move upwards in the barrel body, solid hydrates are gradually formed in the barrel body due to the cooling of the inner coil; The double-screw stirring paddle continuously breaks the gas-liquid phase interface and prevents the hydrates from gathering and growing on the inner coil and the inner wall thereof, so that the formed solid hydrates reach the upper part of the barrel body together with the gas-liquid phase and are separated; The unreacted gas phase is continuously discharged through the gas phase discharge port, and the mixture of the solid hydrates and the liquid phase is continuously discharged from the liquid phase discharge port.

Images