A system and method for enhancing gas hydrate formation by utilizing wall climbing process

Abstract

The present invention relates to the field of gas hydrate formation enhancement, and in particular to a system and method for enhancing gas hydrate formation by means of a wall climbing process. In the present invention, hydrates are induced to grow upward along the wall surface. In this process, the initially generated hydrates will form a lot of capillary channels, and the reaction liquid will move upward along these capillary channels under the action of capillary force until the front end contacts the gas-rich phase to form hydrates. This cycle continues until all the reaction liquids have reacted. In the reaction process, hydrates are induced to "climb the wall" upwards to form, rather than growing towards the liquid phase. This can not only enhance the mass transfer between gas and liquid, but also enhance the mass transfer between gas and hydrates.

Description

Technical Field

[0001] The present invention relates to the field of gas hydrate formation enhancement, and in particular to a system and method for enhancing gas hydrate formation by means of a wall climbing process. Background Art

[0002] Gas hydrates are complexes formed by gas and water under low-temperature, high-pressure conditions. Due to their excellent physical and chemical properties, researchers have developed a series of promising application technologies, including hydrate-based natural gas solidification, storage, and transportation, and hydrate-based gas separation. However, the industrial application of these technologies has generally encountered challenges such as slow hydrate formation rates, low water conversion rates, and low hydrate gas extraction yields. Hydrate formation is a process accompanied by material transfer and energy changes, and is essentially controlled by heat and mass transfer. Therefore, enhancing hydrate formation primarily focuses on enhancing mass transfer.

[0003] Traditional methods for enhancing mass transfer primarily include mechanical methods such as stirring, spraying, and bubbling. These methods primarily enhance gas-liquid mass transfer by increasing the disturbance between the gas and liquid and improving the degree of contact between the gas and liquid. However, these methods are energy-intensive, require external power equipment, and are only suitable for small-scale production. Specifically, in existing technologies, hydrates generally grow toward the liquid phase during the reaction.

[0004] The literature "Hao Wenfeng, Fan Shuanshi, Wang Jinqu. Effect of stirring on the formation of methane hydrate [J]. Natural Gas Chemical Industry, 2005(03):5-7+12." studied the effect of stirring on the formation of hydrate in detail.

[0005] The document "Cheng Chuanxiao, Li Lun, Hu Shen, et al. Study on enhancing the nucleation and growth of methane hydrate by bubbling method [J]. Low Temperatures and Superconductivity, 2021, 49(02): 55-60+104." discusses the promoting effect of bubbling on the nucleation and growth of hydrates.

[0006] The literature "Hao Wenfeng, Sheng Wei, Fan Shuanshi, et al. Experimental study of methane hydration reaction in a spray reactor [J]. Journal of Wuhan University of Technology, 2007(12):39-43" evaluated the advantages of the spray method in enhancing hydrate formation. In addition, the introduction of surfactants can also reduce the interfacial tension between gas and liquid to a certain extent, thereby enhancing gas-liquid mass transfer.

[0007] The patent "A preparation method of a gas hydrate promoter" (200910030246.2, publication (announcement) number CN101514300A) proposes a promoter composed of sodium chloride and sodium lauryl sulfate.

[0008] The patent "A Method for Preparing Methane Hydrate" (2019101807608, Publication (Announcement) No. CN109735373A) proposes a method and means for promoting the formation of methane hydrate using fluorosurfactants. However, these surfactants are generally inefficient in promoting hydrate formation, are prone to varying degrees of environmental damage, are costly, and are uneconomical.

[0009] However, none of the above existing technologies can solve the problem of low gas hydrate formation efficiency in the existing technologies. Therefore, it is urgent to develop a method for promoting hydrate formation with simple equipment, low cost, easy operation and high efficiency. Summary of the Invention

[0010] The purpose of the present invention is to solve the problems existing in the prior art and provide a system and method for enhancing the formation of gas hydrates by means of a wall climbing process.

[0011] In order to solve the problems existing in the prior art, the present invention adopts the following technical solutions:

[0012] A system for enhancing gas hydrate formation by utilizing a wall climbing process, comprising a liquid supply system, a gas supply system, a reactor, and a hydrate storage tank;

[0013] The liquid supply system, the gas supply system and the hydrate storage tank are respectively connected to the reactor;

[0014] The reactor is used for generating hydrates. The reactor is a √-shaped reactor, and the output end of the reactor is located higher than the input end of the reactor.

[0015] As an improvement of the technical solution of the system for enhancing hydrate formation by means of a wall climbing process of the present invention, the reactor includes a first input end, a second input end, a first output end, and a second output end;

[0016] The first input end and the second input end are connected to the liquid supply system and the gas supply system respectively, the first output end is connected to the outside, and the second output end is connected to the hydrate storage tank.

[0017] As an improvement to the technical solution of the system for enhancing hydrate formation by means of a wall climbing process of the present invention, the hydrate storage tank is arranged directly below the second output end.

[0018] As an improvement to the technical solution of the system for enhancing hydrate formation by means of a wall climbing process of the present invention, the liquid supply system includes a liquid storage tank, a first one-way liquid valve, a liquid pump and a second one-way liquid valve connected in sequence through pipelines, and the liquid storage tank is arranged at a position away from the input end of the reactor.

[0019] As an improvement to the technical solution of the system for enhancing hydrate formation by means of a wall climbing process of the present invention, the gas supply system includes a gas source, a second one-way gas valve, a booster and a first one-way gas valve connected in sequence through pipelines, and the gas source is arranged at a position away from the input end of the reactor.

[0020] As an improvement to the technical solution of the system for enhancing hydrate formation by means of a wall climbing process of the present invention, the reactor is divided into three water-cooled jacket sections along its length, each of the water-cooled jacket sections is connected to a temperature regulation system, and the temperatures of the three water-cooled jacket sections form a temperature gradient.

[0021] As an improvement to the technical solution of the system for enhancing hydrate formation by means of a wall climbing process of the present invention, the reactor includes a first reaction section and a second reaction section connected to each other as a whole, the first reaction section extending from top to bottom, and the second reaction section extending from bottom to top; the connection between the first reaction section and the second reaction section forms a protruding end protruding downward.

[0022] As an improvement to the technical solution of the system for enhancing hydrate formation by means of a wall climbing process of the present invention, the second reaction section is a wall climbing section, and spiral blades may be provided in the wall climbing section.

[0023] As an improvement to the technical solution of the system for enhancing hydrate formation by means of the wall climbing process of the present invention, the interior of the reactor is subjected to metal surface modification, which is achieved individually or in combination by adding additives, changing the properties of the reactor reaction wall and applying a temperature gradient.

[0024] A method for enhancing gas hydrate growth by utilizing a wall climbing process comprises the following steps:

[0025] The liquid supply system supplies liquid to the reactor, and the gas supply system supplies gas to the reactor to create an environment conducive to hydrate formation. During the hydrate formation process, hydrates grow upward along the wall surface in the √-shaped reactor and form hydrates. After hydrate formation, the hydrates that climb the wall are stored in the hydrate storage tank at the hydrate outlet under the action of gravity.

[0026] Beneficial effects of the present invention:

[0027] 1. In the present invention, the "wall climbing" effect is used to enhance the formation of gas hydrates without consuming additional energy like stirring, bubbling and spraying, thereby greatly reducing operating costs.

[0028] 2. In this invention, the "wall-climbing" effect is used to enhance gas-liquid-solid mass transfer, eliminating the complexities of device design such as stirring, bubbling, and spraying, significantly extending the effectiveness and service life of hydrate production equipment. This "wall-climbing" enhancement successfully enables hydrate growth in a gas-rich phase, changing the traditional hydrate formation method from growth in a water-rich phase. This significantly enhances gas-liquid and hydrate-gas mass transfer, ultimately increasing hydrate gas lift yields and providing a rational path for the industrialization of hydrate comprehensive utilization technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the present invention.

[0030] Explanation of the accompanying symbols: 1-liquid storage tank; 2-first one-way liquid valve; 3-liquid pump; 4-second one-way liquid valve; 5-first refrigerator; 6-second refrigerator; 7-third refrigerator; 8-safety valve; 9-first water-cooling jacket section; 10-second water-cooling jacket section; 11-third water-cooling jacket section; 12-hydrate outlet; 13-reactor; 14-first one-way gas valve; 15-booster; 16-second one-way gas valve; 17-gas source; 18-hydrate storage tank; 19-gate valve. DETAILED DESCRIPTION

[0031] In order to make the purpose of the invention, technical solutions and beneficial effects of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0032] like Figure 1 As shown, a system for enhancing gas hydrate formation by means of a wall climbing process includes a liquid supply system, a gas supply system, a reactor 13 and a hydrate storage tank 18; the liquid supply system, the gas supply system and the hydrate storage tank 18 are respectively connected to the reactor 13; the reactor 13 is used for hydrate formation, the reactor 13 is a √-shaped reactor 13, and the position of the output end of the reactor 13 is higher than the position of the input end of the reactor 13.

[0033] The present invention aims to address the problems encountered in the industrialization of hydrate technology, such as slow hydrate formation rate, low gas lift volume, and low water conversion rate, by providing a system and method for efficient gas-liquid-solid mass transfer. This significantly improves the hydrate formation rate, gas lift volume, and water conversion rate.

[0034] Specifically, in the present invention, hydrates are induced to grow upward along the wall. During this process, the initially formed hydrates form numerous capillary channels, and the reaction liquid, under the action of capillary forces, moves upward along these capillary channels until the front end contacts the gas-rich phase to form hydrates. This cycle continues until all the reaction liquid has reacted. During the reaction process, hydrates are induced to "climb the wall" to form, rather than growing into the liquid phase. This enhances mass transfer not only between gas and liquid, but also between gas and hydrate.

[0035] In order to avoid the formation of hydrate film due to a high reaction driving force, the initial hydrate formation condition in the present invention is recommended to be between 1.8 and 2.7 times the gas hydrate phase equilibrium condition, preferably 2.2 times.

[0036] In some embodiments of the present invention, the interior of reactor 13 undergoes metal surface modification, which can be achieved individually or in combination by adding additives, modifying the properties of the reactor wall, and applying a temperature gradient. The hydrate "wall climbing" effect can be achieved individually or in combination by adding additives, modifying the properties of the reactor wall, and applying a temperature gradient. Modifying the properties of the reactor wall primarily refers to altering the hydrophilicity and hydrophobicity of the metal wall.

[0037] Furthermore, since reactor 13 is a √-shaped reactor 13, it includes a first reaction section and a second reaction section that are integrally connected. The first reaction section extends downward from the top, while the second reaction section extends upward from the bottom. The connection between the first and second reaction sections forms a downwardly projecting protrusion. Thus, a downwardly concave depression is formed within reactor 13 at the connection between the first and second reaction sections. The reaction liquid can accumulate in the depression, providing sufficient reaction liquid for hydrate formation.

[0038] Furthermore, the depressed portion can be used as a starting point for hydrate formation, and the hydrate grows upward along the wall surface of the second reaction section.

[0039] In some embodiments of the present invention, the reactor 13 includes a first input end, a second input end, a first output end, and a second output end. The first input end and the second input end are connected to the liquid supply system and the gas supply system, respectively. The first output end is connected to the outside world, and the second output end is connected to the hydrate storage tank 18. The second output end is the hydrate outlet 12.

[0040] The first input end and the second input end are both arranged at the first reaction section, and the first input end can be arranged at the end of the first reaction section, and the second input end can be arranged at the upper part of the first reaction section; the first output end and the second output end are arranged at the second reaction section, the first output end is arranged at the end of the second reaction section, and the second output end is arranged at the lower part of the second reaction section of the reactor 13.

[0041] When hydrates are generated and reach the hydrate outlet 12, they are collected along the pipeline and stored in the hydrate storage tank 18. Preferably, the hydrate storage tank 18 is located directly below the second output end. Hydrates that climb the wall are stored in the hydrate storage tank 18 at the hydrate outlet 12 under the action of gravity.

[0042] Furthermore, a gate valve 19 is provided between the reactor 13 and the hydrate storage tank 18 through a pipeline. The hydrate climbing the wall falls into the pipeline at the hydrate outlet 12 under the action of gravity and is transported to the hydrate storage tank 18 for storage through the gate valve 19.

[0043] Furthermore, the second reaction section is a wall climbing section, and spiral blades may be provided in the wall climbing section. Through the slow rotation of the spiral blades, the hydrates on the wall surface can be gradually brought to the hydrate outlet 12 for output.

[0044] In some embodiments of the present invention, the liquid supply system includes a liquid storage tank 1, a first one-way liquid valve 2, a liquid pump 3 and a second one-way liquid valve 4 connected in sequence by pipelines, and the liquid storage tank 1 is arranged at a position away from the input end of the reactor 13.

[0045] In some embodiments of the present invention, the gas supply system includes a gas source 17, a second one-way gas valve 16, a booster 15 and a first one-way gas valve 14 connected in sequence through a pipeline, and the gas source 17 is arranged at a position away from the input end of the reactor 13.

[0046] In detail, in the present invention, the liquid storage tank 1 in the liquid supply system is filled with liquid, which can be a hydrate reaction liquid. The hydrate reaction liquid contains an additive that enhances the "wall climbing" effect of hydrates. The hydrate reaction liquid passes through the first one-way liquid valve 2, and then under the action of the liquid pump 3, flows through the second one-way liquid valve 4 and enters the reactor 13 through the first input end, completing the liquid inlet process during the hydrate growth process.

[0047] After the gas in the gas source 17 in the gas supply system passes through the second one-way gas valve 16, it flows through the first one-way gas valve 14 under the action of the booster 15, and then enters the reactor 13 through the second input end, so that the pressure in the reactor 13 reaches the set pressure, completing the gas intake process in the hydrate formation process.

[0048] Before hydrates are formed, an environment conducive to hydrate formation is formed under the joint action of the liquid supply system and the gas supply system.

[0049] During hydrate formation, hydrates are induced to grow upward along the walls of the √-shaped reactor 13. During this process, the initially formed hydrates form numerous capillary channels, along which the reaction liquid, under capillary force, moves upward until the front end contacts the gas-rich phase to form hydrates. This cycle continues until all the reaction liquid has reacted. During the reaction process, hydrates are induced to "climb the walls" rather than grow toward the liquid phase. This enhances mass transfer not only between the gas and the liquid, but also between the gas and the hydrates.

[0050] After hydrates are generated, the hydrates that climb the wall are stored in the hydrate storage tank 18 at the hydrate outlet 12 under the action of gravity.

[0051] In more detail, in the present invention, the outlet end of the liquid storage tank 1 is connected to the input end of the first one-way liquid valve 2; the output end of the first one-way liquid valve 2 is connected to the input end of the liquid pump 3; the output end of the liquid pump 3 is connected to the input end of the second one-way liquid valve 4; the output end of the second one-way liquid valve 4 is connected to the first input end of the √-type reactor 13; the first output end of the √-type reactor 13 is connected to the input end of the safety valve 8; the output end of the safety valve 8 is connected to the air; the second output end of the √-type reactor 13 is connected to the input end of the gate valve 19; the output end of the gate valve 19 is connected to the input end of the hydrate storage tank 18; the output end of the gas source 17 is connected to the input end of the second one-way gas valve 16; the output end of the second one-way gas valve 16 is connected to the input end of the booster 15; the output end of the booster 15 is connected to the input end of the first one-way gas valve 14; the output end of the first one-way gas valve 14 is connected to the second input end of the √-type reactor 13.

[0052] Furthermore, the √-shaped reactor 13 is equipped with a temperature sensor and a pressure sensor, which can be used to monitor the changes in temperature and pressure in the reactor 13 in real time, so as to adjust the delivery of the liquid supply system and the gas supply system as needed to maintain the environment for hydrate formation in the reactor 13.

[0053] In some embodiments of the present invention, the reactor 13 is divided into three water-cooled jacket sections along its length. Each water-cooled jacket section is connected to a temperature control system, and the temperatures of the three water-cooled jacket sections form a temperature gradient. Since each water-cooled jacket section is connected to a temperature control system, the temperature control system is used to adjust the temperature of each water-cooled jacket section to form a temperature gradient, thereby inducing hydrates to climb the wall during the hydrate formation process. The temperature control system in the present invention is preferably a refrigerator.

[0054] In detail, the first water-cooling jacket section 9 is connected to the first refrigerator 5, the second water-cooling jacket section 10 is connected to the second refrigerator 6, and the third water-cooling jacket section 11 is connected to the third refrigerator 7. The temperature of each water-cooling jacket section is correspondingly adjusted by different refrigerators.

[0055] The present invention also provides a method for enhancing the growth of gas hydrates by means of a wall climbing process, comprising the following steps: a liquid supply system supplies liquid to a reactor, and a gas supply system supplies gas to the reactor, so as to form an environment conducive to hydrate formation; during the hydrate formation process, hydrates grow upward along the wall surface in a √-shaped reactor to form hydrates; after the hydrates are formed, the wall-climbing hydrates are stored in a hydrate storage tank at the hydrate outlet under the action of gravity.

[0056] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

Claims

1. A system for enhancing gas hydrate formation by means of a wall climbing process, characterized in that: It includes a liquid supply system, a gas supply system, a reactor and a hydrate storage tank; The liquid supply system, the gas supply system and the hydrate storage tank are respectively connected to the reactor; The reactor is used for generating hydrates. The reactor is a √-shaped reactor, and the output end of the reactor is located higher than the input end of the reactor.

2. The system for enhancing gas hydrate formation by wall climbing process according to claim 1, characterized in that: The reactor comprises a first input end, a second input end, a first output end and a second output end; The first input end and the second input end are connected to the liquid supply system and the gas supply system respectively, the first output end is connected to the outside, and the second output end is connected to the hydrate storage tank.

3. The system for enhancing gas hydrate formation by wall climbing process according to claim 2, characterized in that: The hydrate storage tank is arranged directly below the second output end.

4. The system for enhancing gas hydrate formation by wall climbing process according to claim 1, characterized in that: The liquid supply system includes a liquid storage tank, a first one-way liquid valve, a liquid pump and a second one-way liquid valve which are sequentially connected through pipelines. The liquid storage tank is arranged at a position far away from the input end of the reactor.

5. The system for enhancing gas hydrate formation by wall climbing process according to claim 1, characterized in that: The gas supply system includes a gas source, a second one-way gas valve, a booster and a first one-way gas valve which are sequentially connected through a pipeline. The gas source is arranged at a position far away from the input end of the reactor.

6. The system for enhancing gas hydrate formation by wall climbing process according to claim 1, characterized in that: The reactor is divided into three water-cooling jacket sections along its length direction. Each of the water-cooling jacket sections is connected to a temperature regulating system. The temperatures of the three water-cooling jacket sections form a temperature gradient.

7. The system for enhancing gas hydrate formation by wall climbing process according to claim 1, characterized in that: The reactor includes a first reaction section and a second reaction section which are connected to each other as a whole. The first reaction section is extended from top to bottom, and the second reaction section is extended from bottom to top. The connection between the first reaction section and the second reaction section forms a protruding end protruding downward.

8. The system for enhancing gas hydrate formation by wall climbing process according to claim 7, characterized in that: The second reaction section is a wall climbing section, and spiral blades may be provided in the wall climbing section.

9. The system for enhancing gas hydrate formation by wall climbing process according to claim 1, characterized in that: The interior of the reactor is subjected to metal surface modification, which is achieved individually or in combination by adding additives, changing the properties of the reactor reaction wall, and applying a temperature gradient.

10. A method for enhancing gas hydrate growth by means of a wall climbing process, characterized in that: The following steps are included: The liquid supply system supplies liquid to the reactor, and the gas supply system supplies gas to the reactor to create an environment conducive to hydrate formation. During the hydrate formation process, hydrates grow upward along the wall surface in the √-shaped reactor and form hydrates. After hydrate formation, the hydrates that climb the wall are stored in the hydrate storage tank at the hydrate outlet under the action of gravity.

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