Liquid carbon dioxide ultrasonic emulsification equipment, emulsification method thereof and quantitative characterization method of demulsification process of liquid carbon dioxide ultrasonic emulsification equipment

Abstract

The invention relates to the technical field of emulsification, in particular to liquid carbon dioxide ultrasonic emulsification equipment, an emulsification method thereof and a quantitative characterization method of a demulsification process of the liquid carbon dioxide ultrasonic emulsification equipment, the liquid carbon dioxide ultrasonic emulsification equipment comprises a reaction kettle device, a high-pressure sealing flange ring, an ultrasonic device and a control system; the reaction kettle device comprises a reaction kettle, a temperature module, a pressure module and a window module, the reaction kettle contains a mixed solution of a surfactant and liquid carbon dioxide, the temperature module adjusts the temperature, the pressure module adjusts the pressure, and the window module shows the morphology of the mixed solution; emulsifying the mixed solution into a carbon dioxide / water emulsion by using an ultrasonic device; the control system comprises an image module, a control module and a processing module, the image module collects an emulsion morphology image through the window module, the processing module analyzes the emulsification effect according to the image, the control module controls emulsification parameters according to the emulsification effect, and the emulsification parameters comprise the temperature and pressure of the reaction kettle and the power and frequency of the ultrasonic device. The equipment provided by the invention can realize intelligent feedback regulation and control of the emulsification process.

Description

Technical Field

[0001] This application relates to the field of emulsification technology, and in particular to a liquid carbon dioxide ultrasonic emulsification device and emulsification method thereof, and a quantitative characterization method for the demulsification process thereof. Background Technology

[0002] Hydrate-based CO2 sequestration technology is one of the key means to address challenges such as the intensification of the greenhouse effect and the frequent occurrence of extreme weather. It utilizes the characteristics of forming solid CO2 hydrates in the deep-sea environment, and has advantages such as high gas storage density, strong stability and low leakage risk, making it one of the most promising marine CO2 sequestration solutions.

[0003] However, current hydrate sealing methods still face two major challenges in practical application. First, the injection efficiency is low: existing technologies mostly rely on mechanical injection, which is limited by the pore structure, wettability, and interfacial tension of seabed sediments, resulting in poor permeability and difficulty in fully utilizing sediment space. If chemical promoters are used to improve injection efficiency, it will cause environmental risks. Second, the hydrate conversion rate is low: the high salinity environment on the seabed (salinity of about 3.5 wt%) inhibits hydrate formation, and the coupling of multiple factors such as temperature, pressure, and fluid composition will further exacerbate the uncertainty of hydrate nucleation and growth processes, reducing the hydrate conversion rate. Summary of the Invention

[0004] In view of this, this application provides a liquid carbon dioxide ultrasonic emulsification device and emulsification method, as well as a quantitative characterization method for the demulsification process, which can solve at least one of the above-mentioned technical problems.

[0005] In a first aspect, this application provides a liquid carbon dioxide ultrasonic emulsification device, comprising a reaction vessel, a high-pressure sealing flange, an ultrasonic device, and a control system; the reaction vessel includes a reaction vessel, a temperature module, a pressure module, and a viewing window module; the reaction vessel is configured to contain a mixed solution comprising a surfactant solution and liquid carbon dioxide; the temperature module is configured to adjust the temperature of the reaction vessel; the pressure module is configured to adjust the pressure of the reaction vessel; and the viewing window module is configured to be mounted on the wall of the reaction vessel, thereby displaying the morphology of the mixed solution; at least a portion of the ultrasonic device is disposed in the reaction vessel and configured to interact with the mixed solution. In solution contact, the ultrasonic device is configured to output mechanical vibration to emulsify the mixed solution into a carbon dioxide / water emulsion; the high-pressure sealing flange seals the gap between the reactor and the ultrasonic device; the control system includes an image module, a control module, and a processing module. The image module is configured to acquire images of the morphology of the carbon dioxide / water emulsion obtained by emulsifying the mixed solution through the window module. The processing module is configured to analyze the emulsification effect of the carbon dioxide / water emulsion based on the images. The control module is configured to control emulsification parameters based on the emulsification effect. The emulsification parameters include at least the temperature and pressure of the reactor and the power and frequency of the ultrasonic device.

[0006] The ultrasonic device is integrated into the reactor via a high-pressure sealing flange, enabling stable operation under high pressure conditions. During the emulsification process of the mixed solution, the ultrasonic device efficiently disperses the solution into micron-sized carbon dioxide / water emulsions, improving the emulsification effect. A viewing window module is installed on the reactor, providing an image acquisition window for the image module to observe the morphology of the carbon dioxide / water emulsion. Combined with the image analysis and processing module's adjustment of emulsification parameters, this allows liquid CO2 in the aqueous phase to form highly dispersed microdroplet structures, significantly increasing the contact area between CO2 and water. This provides optimal kinetic conditions for the conversion of the carbon dioxide / water emulsion into CO2 hydrates, improving the conversion efficiency. Furthermore, the ultrasonic device can disrupt the CO2 hydrate membrane barrier during the CO2 hydrate formation process, increasing the contact area between CO2 and water, thereby improving CO2 flowability and distribution uniformity, reducing flow resistance during CO2 injection, and achieving efficient injection and uniform distribution of CO2. The liquid carbon dioxide ultrasonic emulsification equipment of this application organically combines high-pressure ultrasonic emulsification, visual monitoring, intelligent control technology and CO2 hydrate formation. First, it acquires images of the emulsification process in real time through an image module, and then uses image recognition algorithms to analyze the morphology and dispersion state of the emulsion. Based on the recognition results, it adaptively adjusts the ultrasonic emulsification power, frequency and action time, which can realize real-time identification and intelligent feedback control of the emulsification process, create conditions for CO2 hydrate formation, improve the controllability of the emulsification and hydrate formation process, realize the integrated operation of emulsification and hydrate formation, reduce the process of equipment switching and material transfer during hydrate formation, and significantly improve production efficiency and the continuity of the overall process.

[0007] In some embodiments, the ultrasonic device includes a housing and an ultrasonic transducer and an ultrasonic amplitude transformer at least partially housed within the housing. The ultrasonic amplitude transformer is equipped with an ultrasonic tool head. The ultrasonic transducer is configured to output mechanical vibration. At least a portion of the ultrasonic amplitude transformer is disposed within the reaction vessel and in contact with the mixed solution. The ultrasonic amplitude transformer is configured to amplify the amplitude of the mechanical vibration. The ultrasonic tool head is configured to receive the mechanical vibration and transmit it to the mixed solution. The ultrasonic device employs a modular design, with each component precisely fitted to achieve efficient conversion of electrical energy to mechanical energy.

[0008] In some embodiments, the ultrasonic transducer has a frequency of 20 kHz-60 kHz, a power of 500 W-3000 W, and a power adjustment range of 1%~99%. The ultrasonic transducer possesses both high-frequency and high-power ultrasonic output capabilities, enabling efficient emulsification of mixed solutions into micron-sized carbon dioxide / water emulsions. These emulsions exhibit good dispersibility and flowability, reducing interfacial tension and flow resistance during injection, thus improving injection efficiency. Furthermore, the carbon dioxide / water emulsion system increases the contact area between CO2 and water, thereby enhancing CO2 hydrate conversion.

[0009] In some embodiments, the ultrasonic amplitude transformer is a stepped variable diameter structure, and the ultrasonic amplitude transformer adopts a λ / 2 resonance design. The ultrasonic amplitude transformer with the above structure can achieve a 1:2.5 amplitude amplification, generating a cavitation intensity greater than or equal to 0.5 MPa. Ultrasonic cavitation can prepare carbon dioxide / water emulsions with strong stability and good CO2 droplet size uniformity, increasing the contact area between CO2 and water, and improving injection efficiency. Furthermore, the ultrasonic amplitude transformer with the above structure also has good heat dissipation capabilities, further improving the safety and reliability of the liquid carbon dioxide ultrasonic emulsification equipment.

[0010] In some embodiments, the length of the ultrasonic amplitude transformer located inside the reactor is 63 mm or 190 mm. The length of the ultrasonic amplitude transformer is selectable, allowing it to be adapted to the needs of reactors of different specifications.

[0011] In some embodiments, the reactor is made of stainless steel. Using the aforementioned material can improve the reactor's suitability for highly corrosive environments.

[0012] In some embodiments, the roughness Ra of the inner wall surface of the reactor is ≤0.4 μm. When the roughness of the reactor is within the above range, the reactor is easy to clean.

[0013] In some embodiments, the outer wall of the reactor includes a carbon steel insulation layer. The design of the carbon steel insulation layer can reduce heat loss from the reactor.

[0014] In some embodiments, the temperature module includes an embedded heating wire. Using the above-described temperature module, the reactor can be provided with a stable temperature range of -20 ℃ to 200 ℃, and the heating rate can reach 1.0 ℃ / min, thereby improving the conversion rate of hydrates.

[0015] In some embodiments, the viewing window module includes a sapphire viewing window, a titanium alloy sealing flange, and a spiral wound gasket. The sapphire viewing window is mounted to the wall of the reactor via the titanium alloy sealing flange, and the spiral wound gasket is installed between the sapphire viewing window and the reactor, configured to seal the gap between the sapphire viewing window and the reactor. Using the viewing window module configured as described above, the module can withstand a high pressure range of 10 MPa to 60 MPa, a temperature range of -20 ℃ to 200 ℃, and a rapid temperature change of 50 ℃, providing a reliable real-time observation window for the emulsification and hydrate conversion process.

[0016] In some embodiments, the thickness of the sapphire window is 10 mm-15 mm. When the thickness of the sapphire window is within this range, the light transmittance of the window module is greater than 92%.

[0017] In some embodiments, the surfactant includes at least one of nonionic, anionic, or cationic surfactants. Surfactants of these types are beneficial for reducing the interfacial tension between CO2 and water, thereby improving the stability of the carbon dioxide / water emulsion.

[0018] In some embodiments, the reactor is further equipped with a temperature sensor, a pressure sensor, and a lighting system. The control module is electrically connected to the temperature sensor, the pressure sensor, and the lighting system. The control module is also electrically connected to the ultrasonic device. The temperature sensor is configured to detect the temperature of the reactor, and the pressure sensor is configured to detect the pressure of the reactor. The control module is configured to control the temperature and pressure of the reactor, as well as the power and frequency of the ultrasonic device, based on the temperature and pressure results from the temperature and pressure sensors, so that the ultrasonic device is configured to output mechanical vibration under preset conditions. The lighting system is configured to provide a light source to the reactor. The preset conditions include a demulsification interval t of the carbon dioxide / water emulsion greater than 7 hours, or a volume fraction of less than 80% of the carbon dioxide / water emulsion based on the reactor volume. This application's control module, in conjunction with the temperature sensor, pressure sensor, and ultrasonic device, enables controllable operation of the emulsification and hydrate conversion processes of the mixed solution, improving the accuracy of the emulsification and hydrate conversion processes.

[0019] Secondly, this application provides an emulsification method based on a liquid carbon dioxide ultrasonic emulsification device, comprising the following steps: A surfactant solution and liquid carbon dioxide are injected into a reaction vessel, and an ultrasonic device is installed on the reaction vessel so that the ultrasonic device comes into contact with the mixed solution. Set the temperature and pressure of the reactor and the power and frequency of the ultrasonic device, start the ultrasonic device, emulsify the mixed solution, and record the temperature and pressure of the reactor and the frequency and power of the ultrasonic device during the emulsification process. Images of the morphology of the carbon dioxide / water emulsion during the emulsification process are acquired. The emulsification effect of the carbon dioxide / water emulsion is analyzed based on the images. The power of the ultrasonic device is adjusted, and the changes in the emulsification effect are observed. The optimal power range is analyzed based on the changes in the emulsification effect. The temperature of the reactor was changed based on the optimal power range, and images of the morphology of the carbon dioxide / water emulsion after the temperature change were re-acquired. The effect of temperature on the emulsification effect of the carbon dioxide / water emulsion was analyzed based on the images before and after the temperature change. By recording the temperature and pressure of the reactor and the frequency and power of the ultrasonic device, and combining the images of the morphology of the carbon dioxide / water emulsion at different power and temperature, a mapping relationship between the morphology of the carbon dioxide / water emulsion and the temperature and pressure of the reactor, and the frequency and power of the ultrasonic device, is established. Based on the mapping relationship, the emulsification effect produced by the combination of temperature and pressure of the reactor and frequency and power of the ultrasonic device is analyzed, and the optimal combination of temperature and pressure of the reactor and frequency and power of the ultrasonic device is determined.

[0020] The emulsification method based on liquid carbon dioxide ultrasonic emulsification equipment provided in this application involves ultrasonically emulsifying a mixed solution composed of surfactant emulsion and liquid carbon dioxide under high pressure, different temperatures, and different power conditions, and recording images of the morphology of the carbon dioxide / water emulsion during the change of various parameters. The relationship between the morphology of the carbon dioxide / water emulsion and the emulsification parameters (temperature and pressure of the reactor, frequency and power of the ultrasonic device) is analyzed, providing the optimal combination of reactor temperature and pressure, and ultrasonic device frequency and power to improve the emulsification effect of the mixed solution and the conversion efficiency of hydrates.

[0021] Thirdly, this application provides a quantitative characterization method for the demulsification process based on a liquid carbon dioxide ultrasonic emulsification device, comprising the following steps: starting the ultrasonic device, emulsifying the carbon dioxide / water emulsion, and then entering the demulsification process; acquiring data that reflects the phase change of the emulsion system; and determining a set of demulsification kinetic characteristic time parameters t based on the data. d ; where t ds The demulsification initiation time represents the time at which a stable phase boundary is first detected between the dispersed and continuous phases in the emulsion system, indicating the start of the demulsification process; t d10 t d50 and t d90These represent the times when the emulsion breakdown volume reaches 10%, 50%, and 90% of the initial total emulsion volume, respectively; t dc The demulsification completion time represents the time when the emulsion demulsification process ends, the system state stabilizes over time, and the demulsified volume no longer changes significantly over time; based on the demulsification kinetic characteristic time parameter t... d The demulsification process of carbon dioxide / water emulsions was quantitatively analyzed to characterize the stability and demulsification kinetics of the carbon dioxide / water emulsion system. Attached Figure Description

[0022] Figure 1 A schematic diagram of the structure of the liquid carbon dioxide ultrasonic emulsification device provided in this application.

[0023] Figure 2 for Figure 1 A top view of the reactor apparatus of the ultrasonic emulsification device for liquid carbon dioxide.

[0024] Figure 3 for Figure 2 A cross-sectional view of the reactor apparatus along the I-I direction.

[0025] Figure 4 for Figure 2 A cross-sectional view of the reactor apparatus along the II-II direction.

[0026] Figure 5 for Figure 1 The diagram shows the module architecture of the control system for the liquid carbon dioxide ultrasonic emulsification equipment.

[0027] Figure 6 Characterization photographs of the completed carbon dioxide / water emulsion preparation.

[0028] Figure 7 Photographs characterizing the demulsification process of carbon dioxide / water emulsions.

[0029] Explanation of key component symbols: 100. Liquid carbon dioxide ultrasonic emulsification equipment; 1. Reactor assembly; 11. Reactor; 12. Temperature module; 13. Viewing window module; 131. Sapphire viewing window; 132. Titanium alloy sealing flange; 133. Metal spiral wound gasket; 2. High-pressure sealing flange ring; 3. Ultrasonic device; 31. Ultrasonic transducer; 32. Ultrasonic amplitude transformer; 4. Control system; 41. Image module; 42. Control module; 43. Processing module; 5. Temperature sensor; 6. Pressure sensor; 7. Lighting system. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0031] Firstly, regarding the problems of low injection efficiency and low hydrate conversion rate in existing hydrate preparation methods, please refer to... Figures 1-5 This application provides a liquid carbon dioxide ultrasonic emulsification device 100 and an emulsification method based on the liquid carbon dioxide ultrasonic emulsification device 100, which can improve CO2 injection efficiency and CO2 hydrate conversion rate.

[0032] In some embodiments, the specific steps for preparing CO2 hydrate using a surfactant solution and liquid carbon dioxide include: first, mixing the surfactant solution and liquid carbon dioxide to form a mixed solution; the surfactant can improve the stability of the emulsion; and then using a liquid carbon dioxide ultrasonic emulsification device to obtain a carbon dioxide / water emulsion with micron-sized droplets, thereby obtaining an emulsion system with similar, stable, and uniform CO2 droplet sizes. (See also...) Figure 6 , Figure 6 Characterization photographs of the carbon dioxide / water emulsion are shown to illustrate the typical appearance characteristics of the emulsion system on a macroscopic scale, such as... Figure 6 As shown, the carbon dioxide / water emulsion appears uniformly milky white to the naked eye. This milky white appearance mainly originates from the liquid carbon dioxide being dispersed in the aqueous phase as droplets. When visible light is incident on this emulsion system, a significant light scattering effect occurs at the interface between the dispersed phase droplets and the continuous phase. This scattering behavior conforms to the typical characteristics of Mie scattering. By observing this macroscopic phenomenon, the existence state and dispersion characteristics of the dispersed phase in the carbon dioxide / water emulsion can be directly reflected.

[0033] Further, see Figure 7 , Figure 7 The morphological changes of a carbon dioxide / water emulsion during demulsification under static conditions are shown. Over time, the dispersed phase droplets in the emulsion system gradually coalesce and separate, evolving from an initial homogeneous milky-white state to one exhibiting locally transparent regions or a heterogeneous structure. Observing these morphological changes during demulsification can characterize the stability of the emulsion system and its evolution over time.

[0034] Secondly, the carbon dioxide / water emulsion induces the nucleation and growth of hydrates under high pressure. During the conversion of CO2 hydrates, time-triggered vibrations are used to disrupt the membrane barrier of CO2 hydrates, increase the contact area between CO2 and water, increase the amount of CO2 injected, and control the temperature and pressure of the conversion process to provide optimal kinetic and thermodynamic conditions, thereby improving the conversion rate of CO2 hydrates.

[0035] The above-mentioned hydrate conversion process is achieved using a liquid carbon dioxide ultrasonic emulsification device 100. Please refer to [reference needed]. Figure 1 The liquid carbon dioxide ultrasonic emulsification equipment 100 includes a reaction vessel 1, a high-pressure sealing flange ring 2, an ultrasonic device 3, and a control system 4 (in Figure 5 As shown in the diagram, the reaction vessel 1 provides a reaction container for the entire process of emulsification of the mixed solution and demulsification of the carbon dioxide / water emulsion, as well as the conversion and decomposition of hydrates; at least part of the ultrasonic device 3 is located in the reaction vessel 1 and is used to disperse the mixed materials to obtain a carbon dioxide / water emulsion system with similar particle sizes, stability, and uniformity; the high-pressure sealing flange ring 2 is used to seal the gap between the ultrasonic device 3 and the reaction vessel 1, so that the ultrasonic device 3 has a high-pressure resistant design and can operate in a high-pressure environment; the control system 4 is used to realize intelligent control of the entire process, realize controllable operation of the emulsification and hydrate conversion process of the mixed solution, simplify the operation process, reduce manual intervention, and improve the accuracy of the emulsification process and the hydrate conversion process.

[0036] Please refer to Figures 2-4 The reaction vessel device 1 includes a reaction vessel 11, a temperature module 12, a viewing window module 13, and a pressure module (not shown in the figure). The reaction vessel 11 is configured to contain the mixed solution, the temperature module 12 is configured to regulate the temperature of the reaction vessel 11, the pressure module is configured to regulate the pressure of the reaction vessel, and the viewing window module 13 is configured to be mounted on the wall of the reaction vessel 11, allowing the viewing window module 13 to display the morphology of the mixed solution. The reaction vessel device 1 of this application adopts a modular design, and the emulsification of the mixed solution and the visualization of the hydrate conversion process are achieved through the collaborative work of each module.

[0037] In some embodiments, the reactor 11 is made of stainless steel, and its outer wall includes a carbon steel insulation layer. The inner wall surface is mirror-polished, resulting in a roughness Ra ≤ 0.4 μm. Optionally, the roughness Ra of the inner wall surface of the reactor 11 can be 0.040 μm, 0.039 μm, 0.038 μm, 0.037 μm, 0.036 μm, and 0.035 μm, or any range of two of these values. The reactor 11 with the above-mentioned material and structure can withstand a pressure range of 10 MPa-60 MPa, and the design of the carbon steel insulation layer can reduce heat loss from the reactor. At the same time, the stainless steel material can improve the reactor's suitability for highly corrosive environments, giving it excellent acid and alkali resistance (pH 1-14). Combined with the smooth inner wall surface, this improves the safety and ease of cleaning of the emulsification and hydrate conversion processes. Optionally, the reactor 11 may be made of 316L stainless steel and the internal chamber height of the reactor 11 may be 200 mm.

[0038] In some embodiments, the reactor 11 includes an interface for external devices (not shown in the figure). Exemplary external devices include a water pump and a magnetic stirrer. Other devices that further improve emulsification and hydrate conversion efficiency can also be provided, allowing for functional expansion and upgrades of the reactor 1 as needed. The interface further enhances the applicability of the reactor 11.

[0039] In some embodiments, a static mixer (not shown in the figure) is provided in the reactor 11. The static mixer can be used in conjunction with the ultrasonic device 3 to further enhance the emulsification effect of the carbon dioxide / water emulsion obtained by emulsifying the mixed solution. The emulsification effect includes at least the size, stability and uniformity of CO2 droplets in the carbon dioxide / water emulsion. Good emulsification effect means that the carbon dioxide / water emulsion has small particles, high stability and good uniformity.

[0040] In some embodiments, the inner wall surface of the reactor 11 is provided with a groove (not shown in the figure), and the temperature module 12 is embedded in the groove and filled with thermally conductive silicone grease to improve the heat transfer efficiency of the thermally conductive silicone grease. The temperature module 12 of this application includes an embedded heating wire. Using the above-mentioned temperature module 12, the reactor 11 can be provided with a temperature range of -20 ℃ to 200 ℃, and the heating rate can reach 1.0 ℃ / min. Combined with the pressure range of 10 MPa to 60 MPa provided by the reactor 11, the optimal kinetic and thermodynamic conditions can be provided for the conversion of carbon dioxide / water emulsion into hydrate, so that the hydrate conversion rate is greater than or equal to 85%. Optionally, the temperature module 12 includes an embedded Cr20Ni80 heating wire.

[0041] In some embodiments, the number of window modules 13 installed on the reactor 11 can be selected according to actual needs. Optionally, please refer to [further details]. Figures 2-4 There are four viewing window modules 13, which are distributed in pairs along the height of the reactor 11 near the top and bottom of the reactor 11, so as to observe the emulsification and hydration reaction process of the mixed solution from multiple angles.

[0042] The viewing module 13 includes a sapphire viewing window 131, a titanium alloy sealing flange 132, and a spiral wound gasket 133. The spiral wound gasket 133 is a sealing element made by alternating and precisely winding specific metal strips and non-metallic filler strips. It utilizes the flexibility of the non-metallic part to achieve an initial seal and relies on the spring effect of the metal part to maintain the durability of the seal. The sapphire viewing window 131 is installed on the wall of the reactor 11 through the titanium alloy sealing flange 132, and the spiral wound gasket 133 is installed between the sapphire viewing window 131 and the reactor 11, so that the spiral wound gasket 133 is configured to seal the gap between the sapphire viewing window 131 and the reactor 11. The thickness of the sapphire viewing window 131 is 10 mm-15 mm. Optionally, the thickness of the sapphire viewing window 131 can be 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, and 15 mm, or any range of two of the above values. The window module 13 with the above-described composition has a sapphire window 131 with a thickness within the aforementioned range, resulting in a light transmittance of more than 92%. Combined with the sealing effect of the titanium alloy sealing flange 132 and the metal spiral wound gasket 133, the window module 13 can withstand a high pressure range of 10 MPa to 60 MPa, a temperature range of -20 ℃ to 200 ℃, and a rapid temperature change of 50 ℃ / min, providing a reliable real-time observation window for the emulsification and hydrate conversion process.

[0043] In some embodiments, the surfactant includes at least one of nonionic surfactants, such as alkyl glycosides (APG), anionic surfactants, such as sodium dodecyl sulfate (SDS), or cationic surfactants, such as hexadecyltrimethylammonium bromide (CTAB). Surfactants of these types are beneficial for reducing the interfacial tension between CO2 and water, thereby improving the stability of the carbon dioxide / water emulsion.

[0044] In some embodiments, the high-pressure sealing flange 2 comprises a stainless steel skeleton and a polytetrafluoroethylene (PTFE) material disposed on the surface of the stainless steel skeleton. The high-pressure sealing flange 2, as described above, can stably connect the ultrasonic device 3 to the top of the reactor 11, allowing the ultrasonic device 3 to maintain ±15 μm axial vibration freedom under high pressure conditions of 10 MPa-60 MPa, generating a cavitation intensity of not less than 0.5 MPa, ensuring the efficiency and stability of the carbon dioxide emulsification process and the disruption of the hydrate membrane barrier. Furthermore, the high-pressure sealing flange 2 made of the aforementioned material can be used in highly corrosive environments; that is, the high-pressure sealing flange 2 can perform a sealing function for the reactor and the ultrasonic device in chemical environments with pH 1-14, effectively reducing or even preventing leakage of the mixed solution or carbon dioxide / water emulsion, thus ensuring the sealing performance and durability of the ultrasonic device 3 and the reactor 11 under high pressure conditions. Optionally, the high-pressure sealing flange 2 used in this application has an inner diameter of 39 mm, an outer diameter of 130 mm, and a thickness of 22 mm. The high-pressure sealing flange 2 comprises a 316L stainless steel skeleton and a polytetrafluoroethylene (PTFE) material disposed on the surface of the 316L stainless steel skeleton.

[0045] The ultrasonic device 3 is configured to be installed on the top of the reactor 11 via the high-pressure sealing flange 2, and at least a portion of the ultrasonic device 3 passes through the high-pressure sealing flange 2 into the reactor 11 and comes into contact with the mixed solution. The ultrasonic device 3 is configured to output mechanical vibration under preset conditions to maintain the emulsification effect of the carbon dioxide / water emulsion. The preset conditions include a demulsification interval t greater than 7 h (i.e., the phenomenon of phase separation between hydrates and other components in the emulsion system) or a volume ratio of less than 80% of the carbon dioxide / water emulsion based on the volume of the reactor 11. During the time when the ultrasonic device 3 is not in operation, the carbon dioxide / water emulsion is converted into hydrate. When the hydrate in the emulsion system undergoes preliminary separation or stratification with other components, the ultrasonic device 3 will automatically start and output mechanical vibration when the demulsification interval t is greater than 7 h or the volume ratio of carbon dioxide / water emulsion is less than 80% based on the volume of the reactor 11, according to the emulsion stability conditions obtained from a large number of experiments. This maintains the emulsification effect of the carbon dioxide / water emulsion in the reactor 11, resulting in small particles, high stability and good uniformity of the carbon dioxide / water emulsion. In the process of CO2 hydrate formation, the hydrate barrier is destroyed, the contact area between CO2 and water is increased, and the CO2 hydrate conversion rate is improved.

[0046] In some embodiments, please continue to refer to Figure 1The ultrasonic device 3 includes a housing and an ultrasonic transducer 31 and an ultrasonic amplitude transformer 32, both at least partially housed within the housing. The ultrasonic amplitude transformer 32 is equipped with an ultrasonic tool head. The ultrasonic transducer 31 is configured to output mechanical vibration under preset conditions. At least a portion of the ultrasonic amplitude transformer 32 passes through the high-pressure sealing flange ring 2 into the reaction vessel 11 and contacts the mixed solution. The ultrasonic amplitude transformer 32 is configured to amplify the amplitude of the mechanical vibration. The ultrasonic tool head is configured to receive the mechanical vibration and transmit it to the mixed solution, causing the mixed solution to emulsify into a carbon dioxide / water emulsion. The ultrasonic device 3 of this application adopts a modular design, and the components achieve efficient conversion of electrical energy to mechanical energy through precise cooperation.

[0047] In some embodiments, the housing is made of aluminum alloy, and the surface of the housing includes a hard anodized layer with a thickness of 20 μm-30 μm. The ultrasonic device 3 uses a housing made of the above-mentioned material, which combines mechanical support, electromagnetic shielding (greater than or equal to 30 dB), and lightweight characteristics (less than or equal to 2.7 g / cm), providing reliable protection for the ultrasonic transducer and ultrasonic amplitude transformer. Optionally, the housing material may include aerospace-grade 6061-T6 aluminum alloy.

[0048] In some embodiments, the ultrasonic transducer 31 comprises a piezoelectric ceramic material, the surface of which is coated with a silver electrode. Using the ultrasonic transducer 31 configured as described above, electrical energy can be efficiently converted (conversion efficiency greater than or equal to 90%) into longitudinal mechanical vibration. Optionally, the ultrasonic transducer 31 comprises a PZT-8 type piezoelectric ceramic material.

[0049] In some embodiments, the ultrasonic transducer 31 has a frequency of 20 kHz-60 kHz, a power of 500 W-3000 W, and a power adjustment range of 1%~99%. The ultrasonic transducer 31 possesses both high-frequency and high-power ultrasonic output capabilities, enabling it to efficiently emulsify mixed solutions into micron-sized droplets of carbon dioxide / water emulsion (0.1 μm-10 μm), improving emulsification efficiency by over 200%. Furthermore, it breaks down the membrane barrier of CO2 hydrates during hydrate conversion, increasing the contact area between CO2 and water and improving injection efficiency.

[0050] In some embodiments, the emulsification effect under different energy input conditions is analyzed by gradually adjusting the ultrasonic power or ultrasonic treatment time to determine the minimum energy input required for the formation or stabilization of carbon dioxide / water emulsion, thereby obtaining the energy threshold of the emulsification process and providing a basis for optimizing emulsification conditions.

[0051] As an optional technical method of this application, the ultrasonic transducer 31 can use multi-frequency ultrasound (such as using 20 kHz and 40 kHz simultaneously) for emulsification to improve emulsification efficiency and uniformity of carbon dioxide / water emulsion; or, a focused ultrasonic transducer can be used to further enhance the ultrasonic emulsification effect by expanding the amplitude and improving the transduction efficiency.

[0052] In some embodiments, the ultrasonic amplitude transformer 32 includes an oxygen-free copper inner core and an aluminum alloy sleeve fitted onto the surface of the oxygen-free copper inner core. The ultrasonic amplitude transformer 32 with the above-described configuration exhibits good corrosion resistance. Optionally, the aluminum alloy sleeve may be a 7075 aluminum alloy sleeve.

[0053] In some embodiments, the ultrasonic amplitude transformer 32 is a stepped variable diameter structure, and the ultrasonic amplitude transformer 32 adopts a λ / 2 resonance design. The ultrasonic amplitude transformer 32 with the above structure can achieve an amplitude amplification of 1:2.5, generating a cavitation intensity greater than or equal to 0.5 MPa. The ultrasonic cavitation effect can destroy the hydrate film barrier, increase the contact area with water, and improve the injection efficiency by 150%. In addition, the ultrasonic amplitude transformer 32 with the above structure also has good heat dissipation capacity, further improving the safety and reliability of the liquid carbon dioxide ultrasonic emulsification equipment 100.

[0054] In some embodiments, the length of the ultrasonic amplitude transformer 32 located inside the reactor 11 is 63 mm or 190 mm. The length of the ultrasonic amplitude transformer 32 is selectable, allowing it to be adapted to the usage requirements of reactors 11 of different specifications.

[0055] In some embodiments, the ultrasonic tool head is made of titanium alloy. Ultrasonic tool heads made of this material exhibit good corrosion resistance and fatigue life, improving the suitability of the reactor in highly corrosive environments. Optionally, the ultrasonic tool head is made of TC4 titanium alloy.

[0056] Please refer to Figure 5The control system 4 includes an image module 41, a control module 42, and a processing module 43. The image module 41 is configured to acquire images containing the morphology of the mixed solution through a window module 13. The processing module 43 is configured to analyze the emulsification effect of the carbon dioxide / water emulsion based on the images. The control module 42 controls the emulsification parameters of the reactor 1 and the ultrasonic device 3 based on the emulsification effect. The emulsification effect includes at least the particle size, stability, and uniformity of the carbon dioxide / water emulsion, and the emulsification parameters include at least the temperature and pressure of the reactor 11 and the power and frequency of the ultrasonic device 3. Optionally, the control module 42 includes a main control chip, a central processing unit (CPU), or a microcontroller unit (MCU). It may also include other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0057] A viewing window module 13 is installed on the reactor 11, providing a reliable real-time observation window for observing and facilitating the image module 41 to collect the morphology of the mixed solution emulsification, carbon dioxide / water emulsion demulsification, and hydrate formation and decomposition processes within the reactor 11. This significantly improves production efficiency and the overall process continuity, and facilitates the optimization of emulsification parameters. At this time, the image module 41 works in conjunction with the processing module 43. The image module 41 acquires images of the emulsification process in real time, and the processing module 43 analyzes the images using image recognition algorithms to extract characteristic parameters representing the emulsification state, such as emulsion dispersion state, droplet morphology, or emulsion turbidity. Based on these characteristic parameters, the processing module 41 judges the current emulsification state and feeds the recognition results back to the control module 42. The control module 42 automatically adjusts the power, frequency, or action time of the ultrasonic device 3 according to the emulsification state recognition results, thereby achieving adaptive control of the emulsification process and forming a closed-loop control of the emulsification process. This ensures that the emulsification process is carried out under suitable energy input conditions, improving the emulsification effect of the mixed solution and the conversion efficiency of hydrates. The liquid carbon dioxide ultrasonic emulsification device 100 of this application organically combines high-pressure ultrasonic emulsification, visual monitoring and intelligent control technology to achieve intelligent identification and adaptive control of the emulsification process, which significantly improves the conversion efficiency of hydrates.

[0058] In some embodiments, the control system 4 can also combine multiple information such as pressure, temperature or acoustic signals to comprehensively analyze the emulsification process, thereby improving the accuracy of emulsification state identification.

[0059] In some embodiments, the control system 4 can continuously acquire emulsification experimental images and experimental parameters and establish an emulsification process database. By analyzing the correlation between emulsification images and experimental parameters, an emulsification effect prediction model can be further constructed, thereby enabling the prediction, optimization, and intelligent control of the emulsification process under different working conditions (different temperatures, different pressures, or different emulsifier concentrations) or the prediction and optimization of the emulsification effect, providing a reference for the selection of emulsification conditions.

[0060] In some embodiments, the processing module 43 may use machine learning or deep learning algorithms to extract and identify features from the emulsification process image, and establish an emulsification state recognition model to automatically judge the emulsion formation process and stability.

[0061] In some embodiments, the image module 41 includes a CCD imaging system that records images of the morphology of the mixed solution emulsion formation, carbon dioxide / water emulsion demulsification, and hydrate transformation and decomposition processes.

[0062] In some embodiments, the control system 4 further includes a digitally controlled power supply, which is electrically connected to the ultrasonic device 3, and the time, power and frequency of the ultrasonic device 3 can be adjusted by the digitally controlled power supply.

[0063] In some embodiments, the reactor apparatus 1 is further provided with a temperature sensor 5, a pressure sensor 6, and a lighting system 7. A control module 42 is electrically connected to the temperature sensor 5 and the pressure sensor 6. The control module 42 is electrically connected to the ultrasonic device 3 via a digitally controlled power supply, controlling the ultrasonic power, ultrasonic frequency, and ultrasonic time of the ultrasonic device 3, configuring the ultrasonic device 3 to output mechanical vibration under preset conditions. The temperature sensor 5 is configured to detect the temperature of the reactor 11, and the pressure sensor 6 is configured to detect the pressure of the reactor 11. The control module 42 is electrically connected to the temperature sensor 5 and the pressure sensor 6. Based on the detection results of the temperature sensor 5 and the pressure sensor 6, the temperature and pressure of the reactor 11 can be adjusted in real time (e.g., with a control accuracy of ±0.2 MPa), as well as the power and frequency of the ultrasonic device 3. For example, when overpressure occurs (e.g., greater than 20 MPa), the reactor 11 can be automatically depressurized, improving the safety of the mixed solution emulsification process and the hydrate conversion process. The control module 42 can also control the lighting system 7 to provide illumination to the reactor 11. The control module 42 of this application, together with the temperature sensor 5, the pressure sensor 6 and the ultrasonic device 3, enables controllable operation of the emulsification and hydrate conversion processes of the mixed solution, thereby improving the accuracy of the emulsification and hydrate conversion processes.

[0064] In some embodiments, the temperature sensor 5 includes a platinum resistance thermometer. Using the temperature sensor 5, precise temperature control within the reactor 11 of ±1 °C can be achieved in conjunction with the control module 42. Optionally, the temperature sensor 5 includes a Pt100 platinum resistance thermometer.

[0065] In some embodiments, the pressure sensor 6 includes a 316L stainless steel diaphragm piezoresistive sensor, a PTFE-sealed needle valve, and a spring-loaded safety valve. The pressure sensor 6, composed of the above components, can monitor the pressure inside the reactor 11 in real time. Optionally, the pressure sensor 6 includes a 316L stainless steel diaphragm piezoresistive sensor and a PTFE-sealed needle valve.

[0066] In some embodiments, the lighting system 7 includes an LED lighting system that ensures that the graphics module 41 can still clearly capture images of the emulsification or hydrate conversion process of the mixed solution under high pressure conditions.

[0067] In some embodiments, the control module 42 further includes an algorithm program that can analyze the temperature and pressure data collected by the temperature sensor 5 and the pressure sensor 6, and automatically optimize the parameters of the emulsification process and the hydrate conversion process.

[0068] In practical applications, the image module 41 provides real-time feedback on the emulsification effect through the window module 13 on the reactor 11, providing image-based information for adjusting parameters in the emulsification and hydrate conversion process. The control system 4 dynamically optimizes the emulsification parameters (temperature and pressure of the reactor 11, and power and frequency of the ultrasonic device 3) through real-time data acquisition and image analysis to achieve the best emulsification effect (small CO2 droplets, high stability, and good uniformity of the carbon dioxide / water emulsion), ensuring the efficient and stable operation of the entire emulsification and hydrate conversion process.

[0069] The liquid carbon dioxide ultrasonic emulsification equipment provided in this application integrates the ultrasonic device 3 and the reaction vessel 11 through a high-pressure sealing flange ring 2, enabling the ultrasonic probe and ultrasonic device 3 to operate stably under the high pressure conditions of the reaction vessel 11. During the emulsification process of the mixed solution, the ultrasonic probe and ultrasonic device 3 can efficiently emulsify and disperse the mixed solution into micron-sized carbon dioxide / water emulsion, thereby improving the emulsification effect of the mixed solution. The reactor 11 is equipped with a viewing window module 13, which provides an image acquisition window for the carbon dioxide / water emulsion morphology to the image module 41. Combined with the image analysis and processing module 43 of the control module 42, which adjusts the emulsification parameters, the liquid CO2 in the system forms a highly dispersed microdroplet structure in the aqueous phase, significantly increasing the contact area between CO2 and water. This provides optimal kinetic conditions for the conversion of carbon dioxide / water emulsion into CO2 hydrate, improving the conversion efficiency of CO2 hydrate. The ultrasonic device 3 can also break down the membrane barrier of CO2 hydrate during the conversion process, increasing the contact area between CO2 and water, thereby improving the fluidity and distribution uniformity of CO2, reducing the flow resistance during CO2 injection, and achieving efficient injection and uniform distribution of CO2. The liquid carbon dioxide ultrasonic emulsification equipment 100 of this application organically combines high-pressure ultrasonic emulsification, visual monitoring, intelligent control technology, and high-pressure hydrate conversion. First, the image module 41 acquires images of the emulsification process in real time, and then uses image recognition algorithms to analyze the morphology and dispersion state of the emulsion. Based on the recognition results, the ultrasonic emulsification power, frequency, and action time are adaptively adjusted, which can realize real-time identification and intelligent feedback control of the emulsification process, create conditions for hydrate conversion, improve the controllability of the emulsification and hydrate conversion process, realize the integrated operation of mixed solution emulsification and hydrate conversion, reduce the process of equipment switching and material transfer during hydrate formation, and significantly improve the conversion efficiency of CO2 hydrate and the overall process continuity.

[0070] Secondly, this application provides an emulsification method based on a liquid carbon dioxide ultrasonic emulsification device 100. The emulsification method is a multi-stage ultrasonic emulsification method, including: a first stage low-power pre-dispersion stage, which causes liquid carbon dioxide to form a primary dispersion structure in the aqueous phase; a second stage high-power refining stage, which further reduces the droplet size by enhancing ultrasonic cavitation; and a third stage stabilization stage, which maintains the stability of the emulsion structure by reducing the ultrasonic power, thereby obtaining a carbon dioxide / water emulsion with uniform particle size distribution and good stability.

[0071] Specifically, the steps include the following: Step 1: Inject the surfactant solution into the reaction vessel 11, and then inject liquid carbon dioxide to form a mixed solution, wherein the surfactant solution accounts for less than or equal to 70% of the volume of the reaction vessel 11.

[0072] The reactor 11 is equipped with an ultrasonic device 3, which has good contact with the mixed solution.

[0073] Step 2: The temperature and pressure of the reactor 11 and the power and frequency of the ultrasonic device 3 are set by the control module 42. The ultrasonic device 3 and the reactor 11 are started to emulsify the mixed solution. The processing module 43 records the temperature and pressure of the reactor 11 and the frequency and power of the ultrasonic device 3 during the emulsification process. The image module 41 acquires images of the morphology of the carbon dioxide / water emulsion obtained by the emulsification process of the mixed solution. The processing module 43 is configured to analyze the emulsification effect of the carbon dioxide / water emulsion based on the images. The emulsification effect includes at least the particle size, stability and uniformity of the carbon dioxide / water emulsion. The power of the ultrasonic device 3 is adjusted and the changes in the emulsification effect are observed. The processing module 43 analyzes the optimal power range based on the changes in the emulsification effect.

[0074] Step 3: Based on the optimal power range, the temperature of the reactor 11 is changed. The image module 41 acquires images of the morphology of the carbon dioxide / water emulsion after the temperature change. The processing module 43 is configured to analyze the effect of temperature on the emulsification effect of the carbon dioxide / water emulsion based on the images before and after the temperature change.

[0075] Step 4: By processing the temperature and pressure of the reactor 11 and the frequency and power of the ultrasonic device 3 recorded by the processing module 43, and combining the images of the carbon dioxide / water emulsion at different power and temperature recorded by the image module 41, a model is established for the morphology of the carbon dioxide / water emulsion and the temperature and pressure of the reactor 11, and the frequency and power of the ultrasonic device 3. Step 5: Based on the model, analyze the emulsification effect produced by different combinations of temperature and pressure of reactor 11, frequency and power of ultrasonic device 3, and determine the optimal combination of temperature and pressure of reactor 11, frequency and power of ultrasonic device 3.

[0076] The emulsification method based on the liquid carbon dioxide ultrasonic emulsification device 100 provided in this application involves ultrasonically emulsifying a mixed solution composed of surfactant solution and liquid carbon dioxide under high pressure, different temperatures, and different power conditions, and recording images of the morphology of the carbon dioxide / water emulsion during the change of various parameters. The relationship between the morphology of the carbon dioxide / water emulsion and the emulsification parameters (temperature and pressure of the reactor 11, frequency and power of the ultrasonic device 3) is analyzed, providing the optimal combination of temperature and pressure of the reactor 11 and frequency and power of the ultrasonic device 3 to improve the emulsification effect of the mixed solution and the conversion efficiency of hydrates.

[0077] Thirdly, this application also provides a quantitative characterization method for the demulsification process based on a liquid carbon dioxide ultrasonic emulsification device, comprising the following steps: The ultrasonic device is activated to emulsify the carbon dioxide / water emulsion, which then enters the demulsification process. Data reflecting the phase changes of the emulsion system is acquired, and a set of demulsification kinetic characteristic time parameters t are determined based on the data. d ; where t ds The demulsification initiation time represents the time at which a stable phase boundary is first detected between the dispersed and continuous phases in the emulsion system, indicating the start of the demulsification process; t d10 t d50 and t d90 These represent the times when the emulsion breakdown volume reaches 10%, 50%, and 90% of the initial total emulsion volume, respectively; t dc The demulsification completion time represents the time when the demulsification process ends, the system state stabilizes over time, and the demulsified volume no longer changes significantly over time.

[0078] Based on the time parameter t, a characteristic feature of demulsification kinetics d The demulsification process of carbon dioxide / water emulsions was quantitatively analyzed to characterize the stability and demulsification kinetics of the carbon dioxide / water emulsion system.

[0079] The following describes the emulsification and demulsification processes of carbon dioxide / water emulsions, including the following steps: Step 1: Define the experimental objective Liquid carbon dioxide / water emulsion was prepared by ultrasonic emulsification under high pressure (12 MPa), and the emulsification effect was observed under low temperature (15 ℃) and high temperature (25 ℃) conditions. At the same time, the control system 4 acquired images of the morphology of the carbon dioxide / water emulsion and the formation process of CO2 hydrate in real time through the window module 13, and optimized the emulsification parameters based on the images. The emulsification parameters included the temperature and pressure of the reactor 11 and the frequency and power of the ultrasonic device 3.

[0080] Step 2: Determine the equipment composition (1) Ultrasonic device 3: frequency 20 kHz~60 kHz, power 500-3000 W, power adjustment range 1%~99%.

[0081] (2) Reactor device 1: pressure range 10 MPa~60 MPa, temperature range -20 ℃~200 ℃, using high-strength sapphire window 131.

[0082] (3) Control system 4: CNC power supply, temperature sensor 5, pressure sensor 6, CCD imaging system, LED lighting system.

[0083] Step 3: Clarify the operating procedures (1) Equipment preparation and inspection Check whether the ultrasonic amplitude transformer 32 and ultrasonic tool head of the ultrasonic device 3 are securely installed, and ensure that the high-pressure sealing flange ring 2 is undamaged; check whether the sapphire window 131, temperature module 12 and pressure sensor 6 of the reactor 11 are operating normally; start the control system 4, calibrate the temperature sensor 5 and pressure sensor 6, and ensure that the control system 4 is in standby mode.

[0084] (2) Material preparation The surfactant solution is injected into the reactor 11 in advance, followed by the injection of liquid carbon dioxide, so that the two form a two-phase system inside the reactor. The volume of the surfactant solution does not exceed 70% of the volume of the reactor 11. The reactor 11 is then sealed to ensure no leakage.

[0085] (3) Installation of ultrasonic tool head Based on the inner diameter and height of the reactor 11, select a suitable ultrasonic tool head and install it below the ultrasonic amplitude transformer 32, ensuring that the ultrasonic tool head extends into the reactor 11 so that the length of the ultrasonic amplitude transformer + ultrasonic tool head (e.g., 190 mm) inside the reactor is adapted to the inner diameter of the reactor 11, and the ultrasonic tool head has good contact with the two-phase system.

[0086] (4) Parameter settings and startup The ultrasonic emulsification parameters are set via control system 4: frequency 20 kHz, power 3000 W, power adjustment range 1%~99%, and the pressure of reactor 11 is set to 12 MPa and the temperature to 15 ℃ (low-temperature emulsification). The ultrasonic device 3 and the temperature module 12 of reactor 11 are activated, and the LED lighting system and CCD imaging system are turned on simultaneously.

[0087] (5) Low-temperature emulsification process (15 ℃) The CCD imaging system records in real-time images of the morphology of the carbon dioxide / water emulsion obtained by emulsifying the mixed solution under low temperature and high pressure (12 MPa and 15 ℃). The processing module 43 analyzes the emulsification effect of the carbon dioxide / water emulsion based on the images; it adjusts the ultrasonic power (e.g., gradually decreasing from 3000W to 1500W) and observes the changes in the emulsification effect. The processing module 43 records the emulsification effect of the carbon dioxide / water emulsion at different powers (particle size, stability, and uniformity of the carbon dioxide / water emulsion) and analyzes the optimal power range for emulsification.

[0088] (6) High-temperature emulsification process (25 ℃) The temperature of the reactor 11 was gradually increased from 15 ℃ to 25 ℃, while the pressure was maintained at 12 MPa, the ultrasonic frequency was maintained at 20 kHz, and the power was maintained at 2000 W (optimal power range). The morphology of the carbon dioxide / water emulsion under high temperature and high pressure (12 MPa and 25 ℃) was recorded by the CCD imaging system. The processing module 43 analyzed the effect of temperature on the emulsification effect of the carbon dioxide / water emulsion based on the images before and after the temperature change.

[0089] (7) Data recording and analysis By processing the temperature and pressure of the reactor 11 and the frequency and power of the ultrasonic device 3 recorded by the processing module 43, and recording images of the morphology of the carbon dioxide / water emulsion at different power and temperature, a model is established for the morphology of the carbon dioxide / water emulsion in relation to the temperature and pressure of the reactor 11 and the frequency and power of the ultrasonic device 3.

[0090] During the demulsification process of carbon dioxide / water emulsions, the changes in the stratification state of the carbon dioxide / water emulsion system over time were recorded and analyzed. A set of time parameters t was introduced to characterize the kinetics of the demulsification process. d Among them, t ds The demulsification initiation time of a carbon dioxide / water emulsion is defined as the time at which a stable phase boundary is first detected between the dispersed and continuous phases in the carbon dioxide / water emulsion system, indicating the start of the demulsification process; t d10 t d50 and t d90 t represents the time corresponding to when the demulsification volume of the carbon dioxide / water emulsion reaches 10%, 50%, and 90% of the initial total volume of the carbon dioxide / water emulsion, respectively; dc The demulsification completion time is defined as the time when the carbon dioxide / water emulsion demulsification process ends, the phase state of the system tends to stabilize over time, and the demulsification volume of the carbon dioxide / water emulsion no longer changes significantly over time.

[0091] The aforementioned demulsification volume and characteristic time parameters can be determined based on carbon dioxide / water emulsion morphology images, carbon dioxide / water emulsion volume change records, or other data that can reflect the stratification state of the carbon dioxide / water emulsion. Based on the model and the characteristic time parameter t of the demulsification kinetics... d The emulsification effect produced by different combinations of temperature and pressure of reactor 11 and frequency and power of ultrasonic device 3 was analyzed, and the optimal combination of temperature and pressure of reactor 11 and frequency and power of ultrasonic device 3 was determined.

[0092] (8) Ultrasonic control method based on system state In this application, the control system is configured to determine the state of the carbon dioxide / water emulsion system at different time periods based on the recording and analysis of the changes in the morphology and operating parameters of the carbon dioxide / water emulsion over time, and to dynamically adjust the operation mode of the ultrasonic device according to the state, so as to achieve process control of the emulsification and demulsification process.

[0093] Specifically, the control system can analyze the phase boundary formation of the carbon dioxide / water emulsion system and its time-varying characteristics based on the emulsion morphology image acquired through the window module and the temperature and pressure parameters inside the reactor, thereby determining whether the carbon dioxide / water emulsion system is in at least one of the different stages such as emulsion formation, emulsion stabilization, initial demulsification, demulsification development, or demulsification completion.

[0094] When determining the different stages of an emulsion system, the control system can adjust the input of ultrasonic energy by regulating the power, frequency, or duration of the ultrasonic output of the ultrasonic device. For example, during the emulsion formation stage, the control system can increase or maintain the ultrasonic energy input to promote emulsion formation; during the emulsion stabilization stage, it can decrease or maintain the ultrasonic energy input to maintain the system state; and during the demulsification-related stage, it can change the ultrasonic energy input mode to regulate the development of the demulsification process.

[0095] By adjusting the system state as described above, the operation of the ultrasonic device can be adapted to the actual evolution process of the emulsion system, thereby improving the controllability and energy utilization efficiency of the emulsification and demulsification process of carbon dioxide / water emulsion.

[0096] (9) End of experiment and cleanup Turn off the ultrasonic device 3 and the temperature module 12 of the reactor 11, release the pressure inside the reactor 11, open the reactor 11, remove and store the emulsified material for subsequent analysis. Clean the reactor 11 and the ultrasonic tool head, check the equipment for damage, and prepare for the next experiment.

[0097] Furthermore, those skilled in the art should recognize that the above embodiments are merely illustrative of this application and are not intended to limit this application. Any appropriate changes and variations made to the above embodiments within the essential spirit and scope of this application fall within the scope of this application's disclosure.

Claims

1. A liquid carbon dioxide ultrasonic emulsification device, characterized in that, The liquid carbon dioxide ultrasonic emulsification equipment includes a reaction vessel, a high-pressure sealing flange ring, an ultrasonic device, and a control system; The reaction vessel device includes a reaction vessel, a temperature module, a pressure module, and a viewing window module. The reaction vessel is configured to contain a mixed solution containing a surfactant solution and liquid carbon dioxide. The temperature module is configured to regulate the temperature of the reaction vessel. The pressure module is configured to regulate the pressure of the reaction vessel. The viewing window module is configured to be mounted on the wall of the reaction vessel so that the viewing window module shows the morphology of the mixed solution. At least a portion of the ultrasonic device is disposed in the reactor and configured to contact the mixed solution. The ultrasonic device is configured to output mechanical vibration to emulsify the mixed solution into a carbon dioxide / water emulsion. The high-pressure sealing flange seals the gap between the reactor and the ultrasonic device. The control system includes an image module, a control module, and a processing module. The image module is configured to acquire images of the morphology of the carbon dioxide / water emulsion obtained by emulsifying the mixed solution through the window module. The processing module is configured to analyze the emulsification effect of the carbon dioxide / water emulsion based on the images. The control module is configured to control emulsification parameters based on the emulsification effect. The emulsification parameters include at least the temperature and pressure of the reaction vessel and the power and frequency of the ultrasonic device.

2. The liquid carbon dioxide ultrasonic emulsification equipment according to claim 1, characterized in that, The ultrasonic device includes a housing and an ultrasonic transducer and an ultrasonic amplitude transformer housed at least partially within the housing, the ultrasonic amplitude transformer being provided with an ultrasonic tool head. The ultrasonic transducer is configured to output mechanical vibration; at least a portion of the ultrasonic amplitude transformer is disposed within the reactor and in contact with the mixed solution, the ultrasonic amplitude transformer being configured to amplify the amplitude of the mechanical vibration; the ultrasonic tool head is configured to receive the mechanical vibration and transmit it to the mixed solution.

3. The liquid carbon dioxide ultrasonic emulsification equipment according to claim 2, characterized in that, The ultrasonic device includes at least one of the following features: (1) The frequency of the ultrasonic transducer is 20 kHz-60 kHz, the power is 500 W-3000 W, and the power adjustment range is 1%~99%; (2) The ultrasonic amplitude transformer is a stepped variable diameter structure, and the ultrasonic amplitude transformer adopts a λ / 2 resonance design; (3) The length of the ultrasonic amplitude transformer located in the reactor is 63 mm or 190 mm.

4. The liquid carbon dioxide ultrasonic emulsification device according to claim 1, characterized in that, The reactor apparatus includes at least one of the following features: (1) The material of the reactor includes stainless steel; (2) The roughness Ra of the inner wall surface of the reactor is ≤0.4 μm; (3) The outer wall of the reactor includes a carbon steel insulation layer; (4) The temperature module includes an embedded heating wire.

5. The liquid carbon dioxide ultrasonic emulsification device according to claim 1, characterized in that, The window module includes a sapphire window, a titanium alloy sealing flange, and a metal spiral wound gasket; The sapphire window is mounted on the wall of the reactor via the titanium alloy sealing flange, and the metal spiral wound gasket is installed between the sapphire window and the reactor, the metal spiral wound gasket being configured to seal the gap between the sapphire window and the reactor.

6. The liquid carbon dioxide ultrasonic emulsification device according to claim 5, characterized in that, The thickness of the sapphire window is 10 mm-15 mm.

7. The liquid carbon dioxide ultrasonic emulsification device according to claim 1, characterized in that, The surfactant includes at least one of nonionic surfactants, anionic surfactants, or cationic surfactants.

8. The liquid carbon dioxide ultrasonic emulsification equipment according to claim 1, characterized in that, The reactor is also equipped with a temperature sensor, a pressure sensor, and a lighting system. The control module is electrically connected to the temperature sensor, the pressure sensor, and the lighting system. The control module is also electrically connected to the ultrasonic device. The temperature sensor is configured to detect the temperature of the reactor, the pressure sensor is configured to detect the pressure of the reactor, and the control module is configured to control the temperature and pressure of the reactor, as well as the power and frequency of the ultrasonic device, based on the temperature result from the temperature sensor and the pressure result from the pressure sensor, so that the ultrasonic device is configured to output mechanical vibration under preset conditions; the lighting system is configured to provide a light source inside the reactor; wherein, the preset conditions include a demulsification interval of the carbon dioxide / water emulsion greater than 7 hours, or a volume ratio of the carbon dioxide / water emulsion less than 80% based on the volume of the reactor.

9. An emulsification method based on a liquid carbon dioxide ultrasonic emulsification device, characterized in that, Includes the following steps: A surfactant solution and liquid carbon dioxide are injected into a reaction vessel, and an ultrasonic device is installed on the reaction vessel so that the ultrasonic device comes into contact with the mixed solution. Set the temperature and pressure of the reactor and the power and frequency of the ultrasonic device, start the ultrasonic device, emulsify the mixed solution, and record the temperature and pressure of the reactor and the frequency and power of the ultrasonic device during the emulsification process. Images of the morphology of the carbon dioxide / water emulsion during the emulsification process are acquired. The emulsification effect of the carbon dioxide / water emulsion is analyzed based on the images. The power of the ultrasonic device is adjusted, and the changes in the emulsification effect are observed. The optimal power range is analyzed based on the changes in the emulsification effect. The temperature of the reactor was changed based on the optimal power range, and images of the morphology of the carbon dioxide / water emulsion after the temperature change were re-acquired. The effect of temperature on the emulsification effect of the carbon dioxide / water emulsion was analyzed based on the images before and after the temperature change. By recording the temperature and pressure of the reactor and the frequency and power of the ultrasonic device, and combining the images of the morphology of the carbon dioxide / water emulsion at different power and temperature, a mapping relationship between the morphology of the carbon dioxide / water emulsion and the temperature and pressure of the reactor, and the frequency and power of the ultrasonic device, is established. Based on the mapping relationship, the emulsification effect produced by the combination of temperature and pressure of the reactor and frequency and power of the ultrasonic device is analyzed, and the optimal combination of temperature and pressure of the reactor and frequency and power of the ultrasonic device is determined.

10. A quantitative characterization method for the demulsification process based on a liquid carbon dioxide ultrasonic emulsification device, characterized in that, Includes the following steps: The ultrasonic device is activated to emulsify the carbon dioxide / water emulsion, which then enters the demulsification process. Data reflecting the phase changes of the emulsion system is acquired, and a set of demulsification kinetic characteristic time parameters t are determined based on the data. d ; where t ds The demulsification initiation time represents the time at which a stable phase boundary is first detected between the dispersed and continuous phases in the emulsion system, indicating the start of the demulsification process; t d10 t d50 and t d90 These represent the times when the emulsion breakdown volume reaches 10%, 50%, and 90% of the initial total emulsion volume, respectively; t dc The demulsification completion time represents the time when the emulsion demulsification process ends, the system state tends to stabilize over time, and the volume of the demulsified emulsion no longer changes significantly over time. Based on the time parameter t of the demulsification kinetics d The demulsification process of carbon dioxide / water emulsions was quantitatively analyzed to characterize the stability and demulsification kinetics of the carbon dioxide / water emulsion system.

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