A method and apparatus for pressurizing natural gas

Abstract

The application provides a natural gas pressurization method and a pressurization device. The natural gas pressurization method comprises the following steps: 1) mixing natural gas to be pressurized with a hydration promoter and then performing a hydration reaction to obtain natural gas hydrate; 2) performing pressurization treatment on the natural gas hydrate to obtain pressurized natural gas hydrate; and 3) performing dissociation treatment on the pressurized natural gas hydrate to obtain pressurized natural gas and an aqueous solution. The natural gas pressurization method provided by the application has low energy consumption and low equipment operation noise.

Description

Technical Field

[0001] This invention belongs to the field of natural gas processing technology, and particularly relates to a method and device for pressurizing natural gas. Background Technology

[0002] Natural gas, as a clean energy source, plays a crucial role in the energy structure transformation. Its pressurization technology is a core component of natural gas extraction, transportation, storage, and processing. For example, in scenarios such as onshore natural gas wellheads, offshore oil and gas platforms, coalbed methane, or shale gas fields, the wellhead pressure is typically low, making it difficult to directly meet the process requirements of long-distance pipeline transportation, gas storage injection, or industrial users (such as chemical plants and power plants). Furthermore, in scenarios such as natural gas pipeline peak shaving, emergency gas supply, and ship fuel replenishment, it is necessary to rapidly pressurize low- and medium-pressure natural gas to high pressure to meet the equipment requirements of different pressure levels.

[0003] However, traditional mechanical gas compressors suffer from high energy consumption and high operating noise. Therefore, there is an urgent need to develop a low-energy-consumption and low-noise natural gas boosting method to overcome the bottlenecks of existing technologies in terms of energy consumption and noise, and promote the efficient utilization of natural gas resources. Summary of the Invention

[0004] The main objective of this invention is to provide a method and apparatus for pressurizing natural gas, which has low energy consumption and low operating noise.

[0005] In a first aspect, the present invention provides a method for pressurizing natural gas, comprising the following steps:

[0006] 1) The natural gas to be pressurized is mixed with a hydration accelerator and then subjected to a hydration reaction to obtain natural gas hydrate;

[0007] 2) The natural gas hydrate is pressurized to obtain pressurized natural gas hydrate;

[0008] 3) The pressurized natural gas hydrate is subjected to a dissolution treatment to obtain pressurized natural gas and an aqueous solution.

[0009] In the pressurization method described above, the pressure of the natural gas to be pressurized is 0.2~7MPa;

[0010] And / or, the pressure of the hydration reaction is 0.2~6.8 MPa;

[0011] And / or, the pressure of the pressurized natural gas hydrate is 0.8~60 MPa;

[0012] And / or, the pressure of the pressurized natural gas is 0.8~60MPa;

[0013] And / or, the hydration reaction is carried out at a temperature of 2-15°C for a time of 5-1200 s.

[0014] In the pressurization method described above, the hydration promoter includes at least one of tetrahydrofuran, sodium dodecylbenzenesulfonate, and tetrabutylammonium bromide.

[0015] As described above, the decomposition process includes: heating the pressurized natural gas hydrate and then performing gas-liquid separation to obtain the pressurized natural gas and aqueous solution.

[0016] The heat treatment is performed at a temperature of 25~40℃ for a time of 1~30 minutes.

[0017] The pressurization method described above further includes: the aqueous solution being returned to the recycling process to participate in the hydration reaction.

[0018] In a second aspect, the present invention provides a pressurization device for performing the pressurization method described above, comprising: a hydration reaction unit, a pressurization unit, and a decomposition unit;

[0019] The material outlet of the hydration reaction unit is connected to the material inlet of the pressurization unit, and the material outlet of the pressurization unit is connected to the material inlet of the dissolving unit.

[0020] In the pressurization device described above, the liquid phase outlet of the dissolving unit is connected to the liquid phase inlet of the hydration reaction unit.

[0021] As described above, the pressurization device includes a hydration accelerator supply module, a first temperature control module, and a hydration reaction module.

[0022] And / or, the booster unit includes a booster pump;

[0023] And / or, the resolution unit includes a heating module, a gas-liquid separation module, and a second temperature control module.

[0024] As described above, the pressurization device includes a pressure-resistant hydration reactor in the hydration reaction module.

[0025] And / or, the first temperature control module includes at least one of a jacketed cooling structure and a tube-and-shell cooling structure;

[0026] And / or, the gas-liquid separation module includes at least one of a rotary gas-liquid separator and a sedimentation gas-liquid separator.

[0027] The pressurization device described above further includes a first regulating valve and a cooler, and the liquid phase outlet of the dissolving unit is connected to the liquid phase inlet of the hydration reaction unit in sequence through the first regulating valve and the cooler.

[0028] And / or, the pressurization device further includes a feeding unit, the material outlet of which is connected to the material inlet of the hydration reaction unit, and the feeding unit includes a filter and a second regulating valve;

[0029] And / or, the pressurization device further includes a discharge unit, wherein the material outlet of the depressurization unit is connected to the material inlet of the discharge unit, and the discharge unit includes a third regulating valve and an online monitoring module.

[0030] The natural gas pressurization method provided by this invention first hydrates the natural gas to be pressurized to form natural gas hydrate, then pressurizes the natural gas hydrate, and finally dissolves the pressurized natural gas hydrate to obtain pressurized natural gas and aqueous solution. This method avoids the large energy loss and reliance on complex mechanical systems caused by direct mechanical compression of gaseous natural gas in traditional methods. It also helps to reduce noise and improve the safety, operational stability, and adaptability to complex conditions such as wellhead pressure fluctuations, low pressure and high flow rates, and restricted installation scenarios. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the accompanying drawings used in the description of the embodiments of the present invention or related technologies are briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of a natural gas booster device provided by the present invention.

[0033] Figure label:

[0034] 1: Hydration reaction unit; 2: Pressurization unit; 3: Dissolution unit; 4: First regulating valve; 5: Cooler; 6: Feeding unit; 7: Filter; 8: Second regulating valve; 9: Discharge unit; 10: Third regulating valve; 11: Online monitoring module. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0036] Natural gas boosting technology is widely used in natural gas extraction, gathering and transportation, long-distance pipeline transportation, gas storage injection, and industrial terminal gas supply. It is particularly suitable for scenarios where the wellhead gas pressure is low, the gas source pressure fluctuates greatly, or downstream equipment has specific requirements for the gas supply pressure. For example, in onshore gas wells, coalbed methane wells, shale gas wells, and remote decentralized gas source stations, the original natural gas pressure is often insufficient to directly meet the requirements of pipeline transportation, tank storage, or continuous operation of gas equipment. Therefore, boosting units are usually required on the gas source side. Accordingly, existing systems are generally built around gas pretreatment, gas compression, cooling and pressure stabilization, sealing and leak prevention, and subsequent transportation, forming a boosting architecture with mechanical compression equipment at its core to achieve the boosting of natural gas from a low-pressure state to the target pressure level.

[0037] Currently, mechanical gas compressors such as reciprocating, centrifugal, and screw compressors are commonly used in industry to pressurize natural gas. These devices use mechanical moving parts (such as pistons and impellers) to adiabatically compress gaseous natural gas, raising the low-pressure gas to the target high pressure. For example, reciprocating compressors change the cylinder volume through the reciprocating motion of the piston to achieve gas compression; centrifugal compressors use a high-speed rotating impeller to convert kinetic energy into gas pressure. However, this type of technology has the following inherent drawbacks:

[0038] 1) High energy consumption: The gas-phase compression process is close to adiabatic compression, resulting in low energy conversion efficiency and a large amount of energy being lost as heat.

[0039] 2) Significant noise: Mechanical compressors have a complex structure and many core moving parts (such as pistons, bearings, and seals), which generate significant noise due to strong vibrations during operation.

[0040] The inventors of this application have discovered through extensive research that by sequentially subjecting the natural gas to a hydration reaction, pressurization treatment, and decomposition treatment, the pressure of the natural gas can be significantly increased. Moreover, this pressurization method has low energy consumption and low equipment operating noise.

[0041] Based on this, in a first aspect, the present invention provides a method for pressurizing natural gas, comprising the following steps:

[0042] 1) The natural gas to be pressurized is mixed with a hydration accelerator and then subjected to a hydration reaction to obtain natural gas hydrate;

[0043] 2) The natural gas hydrate is pressurized to obtain pressurized natural gas hydrate;

[0044] 3) The pressurized natural gas hydrate is dissolved to obtain pressurized natural gas and aqueous solution.

[0045] The natural gas pressurization method provided by the present invention can increase the pressure of natural gas by sequentially performing a hydration reaction, pressurization treatment and decomposition treatment on the natural gas to be pressurized. Moreover, the pressurization method has low energy consumption and low equipment operating noise.

[0046] Specifically, in step 1), the natural gas to be pressurized can be fully mixed with the hydration promoter solution through countercurrent or cocurrent flow, and then undergo a hydration reaction in an aqueous medium to convert gaseous natural gas into a slurry form in which hydrate crystals are dispersed in an aqueous solution. There is no clumping, no wall adhesion, and no pipe blockage. This significantly reduces the hydration generation pressure, increases the reaction rate, and solves the problems of harsh conditions, slurry clumping, and equipment corrosion associated with traditional hydration reactions.

[0047] Before the hydration reaction, the low-pressure wellhead natural gas or low-pressure coalbed methane, i.e. the natural gas to be pressurized, can be cleaned and pressure regulated to remove impurities, so as to avoid affecting the hydration reaction and equipment life and achieve the required hydration slurry.

[0048] In step 2), the natural gas hydrate slurry generated in step 1) is pressurized, that is, the liquid phase is pressurized. There is no gas phase compression, no gas turbulence, no mechanical friction, stable operation without vibration, low noise, no corrosion and leakage, and energy consumption is greatly reduced.

[0049] In step 3), the pressurized natural gas hydrate undergoes a dissolution process, meaning the natural gas hydrate crystals are completely decomposed, and the gas-liquid two-phase separation is completed simultaneously, yielding an aqueous solution and high-pressure natural gas. The high-pressure natural gas is then transported out after pressure regulation.

[0050] Therefore, the natural gas pressurization method provided by the present invention can increase the pressure of natural gas by sequentially performing hydration reaction, pressurization treatment and decomposition treatment on the natural gas to be pressurized. Moreover, the pressurization method has low energy consumption and low equipment operating noise.

[0051] In some embodiments of the present invention, the pressure of the natural gas to be pressurized is 0.2 to 7 MPa, for example, it can be a range of 0.2 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa or any two of these.

[0052] In some embodiments, the pressure of the hydration reaction is 0.2 to 6.8 MPa, for example, it can be a range of 0.2 MPa, 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 6.8 MPa or any two of these.

[0053] In some embodiments, the pressure of the pressurized natural gas hydrate is 0.8 to 60 MPa, for example, it can be a range of 0.8 MPa, 1 MPa, 2 MPa, 5 MPa, 10 MPa, 20 MPa, 30 MPa, 40 MPa, 50 MPa, 60 MPa or any two of these.

[0054] In some embodiments, the pressure of the pressurized natural gas is 0.8 to 60 MPa, for example, it can be a range of 0.8 MPa, 1 MPa, 2 MPa, 5 MPa, 10 MPa, 20 MPa, 30 MPa, 40 MPa, 50 MPa, 60 MPa or any combination thereof.

[0055] In some embodiments, the temperature of the hydration reaction is 2 to 15°C, for example, it can be a range of 2°C, 5°C, 7°C, 10°C, 15°C or any two of these; the time is 5 to 1200 s, for example, it can be a range of 5 s, 10 s, 100 s, 200 s, 500 s, 1000 s, 1200 s or any two of these.

[0056] In this invention, the natural gas to be pressurized refers to the feed gas before entering the hydration reaction, with its pressure limited to the range of 0.2~7MPa. This pressure is used to cover various feed conditions such as low wellhead gas inflow, fluctuating gas sources in the gathering and transmission pipeline branches, and distributed gas source stations, so that the feed gas can enter the subsequent hydration formation unit without additional high-energy pre-compression. The pressure of the hydration reaction is limited to 0.2~6.8MPa to ensure that the natural gas is within the thermodynamic window suitable for hydrate formation in the reactor, and to match the pressure of the feed gas and the pressure level of the subsequent pressurization stage. The pressure of the pressurized natural gas hydrate is limited to 0.8~60MPa, indicating that after the natural gas completes hydrate formation, it can maintain a high pressure state during high-pressure transportation, slurry pumping, or closed container transfer, which is conducive to releasing the target pressure of natural gas in the subsequent dissolution stage. The pressure of the pressurized natural gas is also limited to 0.8~60MPa to limit the pressure range of the output gas after dissolution treatment, so as to connect with the pressure requirements of gas storage injection, pipeline pressurization, or industrial terminal gas supply. The temperature for the hydration reaction is limited to 2~15℃ and the time is limited to 5~1200s to ensure that the natural gas completes the formation of hydrates under suitable low temperature conditions and obtains sufficient residence time, so as to avoid the hydration equilibrium being disrupted due to excessively high temperature or the reaction being insufficient due to excessively short time.

[0057] The constraints of the above parameters together constitute the process window from feeding, reaction, pressurization to output, enabling each stage to operate synergistically under controllable thermodynamic and kinetic conditions.

[0058] In some embodiments of the present invention, the hydration promoter includes at least one of tetrahydrofuran, sodium dodecylbenzenesulfonate, and tetrabutylammonium bromide.

[0059] In this invention, the hydration promoter refers to a chemical additive added to the hydration reaction medium. It can improve the rate and stability of natural gas hydrate formation at lower temperatures and over a wider pressure range by reducing the phase equilibrium pressure of natural gas hydrates, shortening the hydration induction period, and promoting crystal nucleation and growth. The hydration promoter participates in the hydration reaction with the aqueous phase throughout the process. During the contact between natural gas and the aqueous phase, it is distributed at the gas-liquid interface, dissolved in the aqueous phase, or exists in a micro-dispersed state within the reaction system. This improves gas-liquid mass transfer conditions and inhibits the aggregation, agglomeration, or blockage of the hydrate slurry in localized areas. Based on the above analysis, the addition of this hydration promoter helps natural gas to be converted into the target hydrate form more quickly, thus providing a stable and continuous material basis for subsequent pressurization and decomposition release of natural gas hydrates.

[0060] Tetrahydrofuran is typically added to the hydration reaction system in the form of an aqueous solution. Tetrahydrofuran molecules can act as guest molecules to induce hydrate formation during the formation of the hydrate cage structure, thereby promoting hydrate formation at lower pressures. Sodium dodecylbenzenesulfonate is typically dispersed in the aqueous phase as a surfactant, which can reduce the gas-liquid interfacial tension and improve the contact efficiency between natural gas and the aqueous phase, thereby accelerating hydrate nucleation and improving slurry flowability. Tetrabutylammonium bromide can typically participate in the formation of the hydrate lattice and regulate the kinetics of the hydration reaction as a structure promoter.

[0061] In some embodiments of the present invention, the decomposition process includes: heating the pressurized natural gas hydrate and then performing gas-liquid separation to obtain pressurized natural gas and an aqueous solution; the heating temperature is 25~40°C, for example, it can be a range of 25°C, 28°C, 30°C, 32°C, 35°C, 38°C, 40°C or any two of these; the time is 1~30 min, for example, it can be a range of 1 min, 3 min, 5 min, 10 min, 15 min, 20 min, 25 min, 30 min or any two of these.

[0062] In this invention, the heat treatment is used to controllably raise the temperature of the pressurized natural gas hydrate under high pressure, so that the crystal structure of the natural gas hydrate undergoes thermal decomposition and releases natural gas while maintaining the system pressure basically stable. The gas-liquid separation treatment is used to separate the gaseous natural gas and the liquid aqueous solution formed after heat decomposition, thereby obtaining pressurized natural gas that can be exported and a recyclable aqueous solution, respectively.

[0063] After separation, the liquid content in the natural gas is less than 0.01 kg liquid / kg gas, and the residual natural gas in the aqueous solution is ≤0.01%, indicating that the gas-liquid separation is relatively thorough.

[0064] Heat treatment can raise the temperature of natural gas hydrates through indirect heating, direct heating, electromagnetic heating, and other methods.

[0065] In some embodiments of the present invention, the aqueous solution is further recycled to participate in the hydration reaction.

[0066] In this invention, the aqueous solution is recycled for participation in the hydration reaction, meaning that the aqueous solution obtained after the decomposition treatment is reintroduced into the hydration reaction process, allowing it to be used again as the liquid phase medium for the formation of natural gas hydrates from the natural gas to be pressurized. During the recycling process, this aqueous solution not only acts as a mass and heat transfer medium but also carries residual hydration promoters, a small amount of dissolved gas, and stable liquid phase components from the previous reaction. This allows it to continue participating in the formation of natural gas hydrates in the next hydration reaction, reducing the amount of fresh water and hydration promoter needed. The entire process is waste-free, with high material utilization and reduced emission load.

[0067] Before the aqueous solution is returned to the recycling system to participate in the hydration reaction, its temperature and pressure can be adjusted, and necessary cooling treatments can be applied to match the conditions of the hydration reaction.

[0068] In a second aspect, the present invention provides a pressurizing device for performing the pressurizing method described above, comprising: a hydration reaction unit 1, a pressurizing unit 2, and a dissolving unit 3; the material outlet of the hydration reaction unit 1 is connected to the material inlet of the pressurizing unit 2, and the material outlet of the pressurizing unit 2 is connected to the material inlet of the dissolving unit 3.

[0069] In this invention, the natural gas to be pressurized is mixed with a hydration promoter in a hydration reaction unit 1 and then subjected to a hydration reaction to obtain a natural gas hydrate slurry. The natural gas hydrate slurry is output from the material outlet of the hydration reaction unit 1 and enters the pressurization unit 2 through the material inlet of the pressurization unit 2 via a transfer pump for pressurization treatment to obtain pressurized natural gas hydrate. The pressurized natural gas hydrate is output from the material outlet of the pressurization unit 2 and enters the dissolution unit 3 through the material inlet of the dissolution unit 3 for dissolution treatment to obtain pressurized natural gas and an aqueous solution.

[0070] The natural gas booster device provided by the present invention can increase the pressure of natural gas by sequentially performing hydration reaction, boosting treatment and decomposition treatment on the natural gas to be boosted. Moreover, the booster device has low energy consumption and low operating noise.

[0071] In some embodiments of the present invention, the liquid phase outlet of the dissolving unit 3 is connected to the liquid phase inlet of the hydration reaction unit 1.

[0072] When the decomposition unit 3 decomposes the pressurized natural gas hydrate, it can separate out a liquid phase aqueous solution. The aqueous solution is output from the liquid phase outlet of the decomposition unit 3 and enters the hydration reaction unit 1 through the liquid phase inlet. It continues to participate in the natural gas hydration reaction as a liquid phase medium for subsequent hydration reactions, thereby forming a liquid phase return path. This can reduce the external water replenishment demand and liquid phase medium discharge, making the liquid phase supply of the hydration reaction more continuous and stable, which is conducive to maintaining the overall material balance and continuous operation of the pressurization unit.

[0073] In some embodiments of the present invention, the hydration reaction unit 1 includes a hydration promoter supply module, a first temperature control module, and a hydration reaction module.

[0074] The hydration promoter supply module provides a medium to the hydration reaction module to promote the rapid formation of hydrates from natural gas; the first temperature control module is used to adjust the temperature conditions required for the hydration reaction, so that the natural gas can be more stably converted into natural gas hydrates that are easy to transport and pressurize in a liquid-solid manner; the hydration reaction module is used to fully contact the low-pressure natural gas with the hydration promoter, and react under the set temperature and pressure conditions to generate a fluid natural gas hydrate slurry, and control the formation rate and location of the hydrate, prevent slurry agglomeration, and prevent pipeline blockage.

[0075] It should be noted that if the hydration accelerator supplied by the hydration accelerator supply module is insufficient to meet the requirements of the hydration reaction, an external hydration accelerator can also be input to accelerate the hydration reaction.

[0076] In some embodiments, the booster unit 2 includes a booster pump.

[0077] The booster unit 2 uses a booster pump to pressurize the natural gas hydrate. Compared with direct mechanical compression of gas phase natural gas, it can reduce the sealing and friction burden caused by high-pressure gas phase compression, thereby reducing energy loss and equipment wear.

[0078] High-pressure, corrosion-resistant booster pumps can be selected, such as corrosion-resistant screw pumps and diaphragm pumps. They have high pressure resistance and are suitable for conveying acidic slurries containing solid hydrate particles.

[0079] In some embodiments, the resolution unit 3 includes a heating module, a gas-liquid separation module, and a second temperature control module.

[0080] The heating module is used to controllably heat the pressurized natural gas hydrate, and works in conjunction with the second temperature control module to decompose the hydrate lattice and release gas within a set temperature window; the gas-liquid separation module is used to separate the released high-pressure natural gas from the formed aqueous solution after the natural gas hydrate decomposes, so as to obtain the target gas product and the recoverable liquid phase respectively.

[0081] In some embodiments of the present invention, the hydration reaction module includes a pressure-resistant hydration reactor.

[0082] The pressure-resistant hydration reactor can withstand the reaction pressure during the natural gas hydration process and provide a stable contact space for gas, water and hydration promoters, so that the hydration reaction can proceed continuously and is not easily disturbed by fluctuations in the gas coming from the wellhead.

[0083] In some embodiments, the first temperature control module includes at least one of a jacketed cooling structure and a tube-and-shell cooling structure.

[0084] The first temperature control module adopts a jacketed cooling structure and / or a tube-and-shell cooling structure, which can remove the exothermic reaction of hydration in a timely manner, maintain a suitable generation temperature, thereby improving the hydration generation efficiency and suppressing reaction instability caused by local overheating.

[0085] In some embodiments, the gas-liquid separation module includes at least one of a rotary gas-liquid separator and a settling gas-liquid separator.

[0086] The gas-liquid separation module uses a rotary gas-liquid separator and / or a settling gas-liquid separator, which can effectively separate the gas phase natural gas and the liquid phase aqueous solution after decomposition, making the gas output more stable and the liquid recovery more complete, which is conducive to liquid phase reuse and closed-loop system operation.

[0087] In some embodiments of the present invention, the pressurization device further includes a first regulating valve 4 and a cooler 5, and the liquid phase outlet of the decomposition unit 3 is connected to the liquid phase inlet of the hydration reaction unit 1 in sequence through the first regulating valve 4 and the cooler 5.

[0088] In this invention, the aqueous solution is output from the liquid phase outlet of the hydration unit 3, and after passing through the first regulating valve 4 and the cooler 5 in sequence, it enters the hydration reaction unit 1 through the liquid phase inlet of the hydration reaction unit 1 to participate in the hydration reaction.

[0089] The aqueous solution discharged from the hydration unit 3 is returned to the hydration reaction unit 1 after passing through the first regulating valve 4 and the cooler 5. The first regulating valve 4 can regulate the pressure and flow rate of the aqueous solution, and the cooler 5 can reduce the temperature of the aqueous solution to a suitable hydration reaction range, thereby improving the stability of aqueous solution reuse and reducing the heat load of the circulating medium.

[0090] In some embodiments, the pressurization device further includes a feeding unit 6, the material outlet of which is connected to the material inlet of the hydration reaction unit 1, and the feeding unit 6 includes a filter 7 and a second regulating valve 8.

[0091] In this invention, the natural gas to be pressurized is filtered by filter 7, and then its flow rate and pressure are regulated by the second regulating valve 8 before being output from the material outlet of the feeding unit 6 and undergoing hydration reaction through the material inlet of the hydration reaction unit 1.

[0092] The filter 7 in the feed unit 6 can remove particulate matter or impurities from the natural gas, and the second regulating valve 8 can regulate the flow rate and pressure of the raw materials entering the hydration reaction unit 1, making it easier to maintain stable reaction conditions and thus improving the continuity of hydration generation.

[0093] In some embodiments, the pressurizing device further includes a discharge unit 9, wherein the material outlet of the depressurizing unit 3 is connected to the material inlet of the discharge unit 9, and the discharge unit 9 includes a third regulating valve 10 and an online monitoring module 11.

[0094] In this invention, the pressurized natural gas is output from the gas outlet of the decomposition unit 3, enters the discharge unit 9 through the gas inlet of the discharge unit 9, is regulated by the third regulating valve 10, and is monitored by the online monitoring module 11 before being output from the gas outlet of the discharge unit 9.

[0095] The third regulating valve 10 in the discharge unit 9 can realize discharge throttling and pressure matching, and the online monitoring module 11 can monitor the discharge status and operating parameters in real time. Therefore, it can reflect the operating conditions of the device in a timely manner and cooperate with the aforementioned reflux and feeding structure to achieve stable control, safe operation and continuous conveying of the pressurization process.

[0096] In summary, this invention incorporates corrosion-resistant isolation valves and pressure monitoring instruments between each unit, forming a closed-loop continuous operation system. The natural gas pressurization efficiency is ≥98%, the aqueous solution recycling rate is ≥99%, the single-cycle loss rate of the hydration accelerator is ≤0.01%, and there is no waste liquid or residue discharge. The device can operate continuously and stably for extended periods. Furthermore, the entire system eliminates the need for a mechanical natural gas compressor, operates with mild parameters, has a compact structure, eliminates high-frequency vibration and loud noise, significantly improves safety, and minimizes wear on core components. It enables long-term continuous and stable pressurization, adapting to different pressure requirements and flow conditions, perfectly meeting the process requirements of natural gas transportation and processing, as well as the needs of natural gas resource utilization processes.

[0097] In addition, the device has no mechanical friction sparks, low operating noise, and is completely sealed without leakage, making it highly safe and suitable for high-risk scenarios such as natural gas wellheads, offshore platforms, and industrial plants.

[0098] Meanwhile, the device has no complex moving parts, has a simple structure, occupies a small area, and has no special requirements for the installation foundation; the formation and dissolution of hydrates are carried out under mild temperature and pressure conditions, and the boost pressure can be flexibly adjusted according to the needs of pressurization and processing, adapting to low-pressure, high-flow natural gas conditions, and has strong tolerance for raw gas pressure fluctuations.

[0099] The hydration accelerator is recyclable, emits no toxic or harmful substances, and produces no waste liquid or residue. It is low-carbon and energy-saving throughout the process and can be perfectly adapted to the natural gas pressurization, transportation, and utilization industries as well as related processes for natural gas resource utilization, thus possessing significant environmental and social benefits.

[0100] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0101] Example 1

[0102] The device in this embodiment is a natural gas booster device, such as... Figure 1 As shown, it includes a hydration reaction unit 1; a pressurization unit 2 (stainless steel high-pressure screw pump); a dissolving unit 3; a first regulating valve 4; a cooler 5; a feeding unit 6; and a discharging unit 9.

[0103] The material outlet of the hydration reaction unit 1 is connected to the material inlet of the pressurization unit 2, the material outlet of the pressurization unit 2 is connected to the material inlet of the dissolving unit 3, the liquid phase outlet of the dissolving unit 3 is connected to the liquid phase inlet of the hydration reaction unit 1 via a first regulating valve 4 and a cooler 5, the material outlet of the feeding unit 6 is connected to the material inlet of the hydration reaction unit 1, and the material outlet of the dissolving unit 3 is connected to the material inlet of the discharge unit 9. The hydration reaction unit 1 includes a hydration accelerator supply module, a first temperature control module, and a hydration reaction module. The dissolving unit 3 includes a heating module (jacketed water bath), a gas-liquid separation module, and a second temperature control module. The hydration reaction module includes a pressure-resistant hydration reactor, the first temperature control module includes a jacketed cooling structure, and the gas-liquid separation module includes a rotary gas-liquid separator. The feeding unit 6 includes a filter 7 and a second regulating valve 8, and the discharge unit 9 includes a third regulating valve 10 and an online monitoring module 11.

[0104] Specifically, the low-pressure wellhead natural gas is filtered through filter 7 to remove dust and impurities, and the pressure is controlled at 0.7 MPa and the temperature at 10°C by the second regulating valve 8. It is then output from the material outlet of the feeding unit 6 and enters the hydration reaction unit 1 through the material inlet. There, it is mixed with a hydration promoter (tetrahydrofuran and sodium dodecylbenzenesulfonate in a mass ratio of 7:3, concentration 6 wt%) to undergo a hydration reaction, yielding natural gas hydrate. The hydration reaction is carried out at a temperature of 8°C, a pressure of 0.6 MPa, a stirring speed of 200 r / min, and a time of 20 min.

[0105] Natural gas hydrate is output from the material outlet of hydration reaction unit 1 and enters pressurization unit 2 through the material inlet of pressurization unit 2 for pressurization treatment, resulting in pressurized natural gas hydrate. The pressure of the pressurized natural gas hydrate is 4 MPa.

[0106] The pressurized natural gas hydrate is output from the material outlet of pressurization unit 2 and enters the material inlet of dissolution unit 3 for dissolution treatment. Specifically, the pressurized natural gas hydrate is first heated, followed by gas-liquid separation to obtain pressurized natural gas and an aqueous solution. The heating temperature is 40℃, the time is 10 minutes, and the pressure of the pressurized natural gas is 4 MPa.

[0107] The aqueous solution is output from the liquid phase outlet of the hydration unit 3, and after passing through the first regulating valve 4 and the cooler 5 in sequence, it enters the hydration reaction unit 1 through the liquid phase inlet to circulate and participate in the hydration reaction. The pressurized natural gas is output from the gas outlet of the hydration unit 3, enters the discharge unit 9 through the gas inlet, is regulated by the third regulating valve 10, and is monitored by the online monitoring module 11 before being output from the gas outlet of the discharge unit 9.

[0108] Example 2

[0109] The method and apparatus for pressurizing natural gas in Example 2 are basically the same as those in Example 1, except that the low-pressure coalbed methane is filtered through filter 7 to remove dust and impurities, and the pressure is controlled at 0.6 MPa and the temperature at 15°C by the second regulating valve 8; the hydration reaction temperature is 5°C and the pressure is 0.5 MPa, and the hydration promoter is tetrabutylammonium bromide with a concentration of 25 wt%; the pressure of the pressurized natural gas hydrate is 6 MPa; and the pressure of the pressurized natural gas is 6 MPa.

[0110] Comparative Example 1

[0111] Comparative Example 1 uses a conventional centrifugal natural gas compressor to pressurize low-pressure wellhead natural gas. The natural gas flow rate and pressurization rate are the same as in Example 1.

[0112] Comparative Example 2

[0113] Comparative Example 2 used a conventional centrifugal natural gas compressor to pressurize low-pressure coalbed methane. The flow rate and pressurization magnitude of the coalbed methane were the same as in Example 2.

[0114] The energy consumption of Comparative Example 1 is 2.8 times that of Example 1, and the operating noise is 1.2 times that of Example 1.

[0115] The energy consumption of Comparative Example 2 is 3.6 times that of Example 2, and the operating noise is 1.2 times that of Example 2.

[0116] Compared with the comparative example, the natural gas pressurization method provided by the present invention can increase the pressure of natural gas by sequentially performing hydration reaction, pressurization treatment and decomposition treatment on the natural gas to be pressurized. Moreover, the pressurization method has low energy consumption and low equipment operating noise.

[0117] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A method for pressurizing natural gas, characterized in that, Includes the following steps: 1) The natural gas to be pressurized is mixed with a hydration accelerator and then subjected to a hydration reaction to obtain natural gas hydrate; 2) The natural gas hydrate is pressurized to obtain pressurized natural gas hydrate; 3) The pressurized natural gas hydrate is subjected to a dissolution treatment to obtain pressurized natural gas and an aqueous solution.

2. The pressurization method according to claim 1, characterized in that, The pressure of the natural gas to be pressurized is 0.2~7MPa; And / or, the pressure of the hydration reaction is 0.2~6.8 MPa; And / or, the pressure of the pressurized natural gas hydrate is 0.8~60 MPa; And / or, the pressure of the pressurized natural gas is 0.8~60MPa; And / or, the hydration reaction is carried out at a temperature of 2-15°C for a time of 5-1200 s.

3. The pressurization method according to claim 1 or 2, characterized in that, The hydration accelerator includes at least one of tetrahydrofuran, sodium dodecylbenzenesulfonate, and tetrabutylammonium bromide.

4. The pressurization method according to any one of claims 1-3, characterized in that, The decomposition process includes: heating the pressurized natural gas hydrate and then performing gas-liquid separation to obtain the pressurized natural gas and aqueous solution; The heat treatment is performed at a temperature of 25~40℃ for a time of 1~30 minutes.

5. The pressurization method according to any one of claims 1-4, characterized in that, Also includes: The aqueous solution is returned to the recycling process to participate in the hydration reaction.

6. A pressurization apparatus for performing the pressurization method according to any one of claims 1-5, characterized in that, include: Hydration reaction unit, pressurization unit, and decomposition unit; The material outlet of the hydration reaction unit is connected to the material inlet of the pressurization unit, and the material outlet of the pressurization unit is connected to the material inlet of the dissolving unit.

7. The booster device according to claim 6, characterized in that, The liquid phase outlet of the dissolution unit is connected to the liquid phase inlet of the hydration reaction unit.

8. The booster device according to claim 6 or 7, characterized in that, The hydration reaction unit includes a hydration promoter supply module, a first temperature control module, and a hydration reaction module; And / or, the booster unit includes a booster pump; And / or, the resolution unit includes a heating module, a gas-liquid separation module, and a second temperature control module.

9. The booster device according to claim 8, characterized in that, The hydration reaction module includes a pressure-resistant hydration reactor; And / or, the first temperature control module includes at least one of a jacketed cooling structure and a tube-and-shell cooling structure; And / or, the gas-liquid separation module includes at least one of a rotary gas-liquid separator and a sedimentation gas-liquid separator.

10. The booster device according to any one of claims 6-9, characterized in that, The pressurization device also includes a first regulating valve and a cooler. The liquid phase outlet of the dissolving unit is connected to the liquid phase inlet of the hydration reaction unit in sequence through the first regulating valve and the cooler. And / or, the pressurization device further includes a feeding unit, the material outlet of which is connected to the material inlet of the hydration reaction unit, and the feeding unit includes a filter and a second regulating valve; And / or, the pressurization device further includes a discharge unit, wherein the material outlet of the depressurization unit is connected to the material inlet of the discharge unit, and the discharge unit includes a third regulating valve and an online monitoring module.

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