Solubility measurement system and solubility measurement method

Abstract

The present application provides a solubility measurement system and a solubility measurement method, wherein the measurement system includes a gas supply device, a piston container, a plunger pump, a delivery pipeline, a first circulating water bath device, a second circulating water bath device, a reaction container, a second pressure sensor, a second temperature sensor, and a data acquisition and control system. The measurement method comprises placing a solid phase auxiliary agent into the reaction container; placing the piston container and the reaction container in a water bath device respectively; opening the gas supply device to inject liquid carbon dioxide into the top space of the piston container; injecting liquid into the bottom space through the plunger pump so that the liquid carbon dioxide in the top space of the piston container is injected into the reaction container; immersing the solid phase auxiliary agent in the liquid carbon dioxide to fully dissolve the solid phase auxiliary agent; after dissolution equilibrium, separating the solid phase auxiliary agent on the separation mechanism from the liquid carbon dioxide; measuring the molar amount of the solid phase auxiliary agent dissolved in the reaction container to calculate the solubility of the solid phase auxiliary agent in the liquid carbon dioxide.

Description

Technical Field

[0001] The present application relates to the technical field of measuring devices, and in particular to a measuring system for measuring the solubility of a solid phase additive in liquid carbon dioxide and a measuring method for measuring the solubility of a solid phase additive in liquid carbon dioxide using the system. Background Art

[0002] Carbon dioxide hydrate is a cage-shaped crystal inclusion complex. Water molecules are combined by hydrogen bonds to form cage-shaped crystals. Carbon dioxide molecules are surrounded by the lattice. Carbon dioxide and water form white crystals under certain temperature and pressure conditions. Carbon dioxide hydrate is widely used in the fields of carbon dioxide capture, utilization and storage (CCUS), cold energy storage, and seawater desalination. The formation of carbon dioxide hydrate often requires the addition of solid phase additives (enhancing additives / inhibiting additives) to regulate its formation process. Most solid phase additives may be soluble in liquid carbon dioxide, so it is important to measure their solubility. In the prior art, most methods for determining the solubility of solid phase additives for hydrates in liquid carbon dioxide rely on indirect tests, which usually cannot accurately reflect the dissolution behavior of solid phase additives under actual application conditions. These methods have problems such as complex operation, low precision, and poor repeatability of results. Summary of the invention

[0003] In order to solve at least one of the above technical problems, the present application embodiment provides a solubility measurement system that can directly measure the solubility of a solid phase additive in liquid carbon dioxide. In addition, the present application embodiment also provides a solubility measurement method using the solubility measurement system.

[0004] The first aspect of the present application provides a solubility measurement system for measuring the solubility of a solid phase auxiliary agent in liquid carbon dioxide, the measurement system comprising a gas supply device, a piston container, a plunger pump, a first circulating water bath device, a second circulating water bath device, a reaction container, and a data acquisition and control system. The gas supply device is used to provide gaseous carbon dioxide. The piston container comprises a cavity and a piston located in the cavity, the piston divides the cavity into a top space and a bottom space, the top space is connected to the gas supply device and is used to accommodate the gaseous carbon dioxide transmitted by the gas supply device. The plunger pump is connected to the bottom space and is used to pressurize the top space to a first pressure. The first circulating water bath device is used to accommodate the piston container and maintain the piston container at a first temperature, so that the gaseous carbon dioxide in the top space is converted into liquid carbon dioxide at a first pressure and a first temperature. The reaction container comprises a container body and a separation mechanism, the container body is connected to the top space of the piston container and is used to accommodate the liquid carbon dioxide transmitted from the top space, the separation mechanism can be movably arranged on the container body, and the separation mechanism is used to carry the solid phase auxiliary agent and mix or separate the solid phase auxiliary agent and the liquid carbon dioxide. The second circulating water bath device is used to accommodate the reaction container and maintain the reaction container at a second temperature, so that the solid phase auxiliary agent is dissolved in the liquid carbon dioxide at a second pressure and a second temperature, and the solid phase auxiliary agent and the liquid carbon dioxide are separated by a separation mechanism after reaching a dissolution equilibrium, and the carbon dioxide in the reaction container is released to the outside after waiting for a predetermined period of time, so that the solid phase auxiliary agent dissolved in the liquid carbon dioxide is precipitated. The data acquisition and control system is used to calculate the solubility of the solid phase auxiliary agent in the liquid carbon dioxide according to the molar amount of the liquid carbon dioxide transmitted from the head space to the container body and the molar amount of the precipitated solid phase auxiliary agent.

[0005] The setting of the separation mechanism of the embodiment of the present application makes it unnecessary to open the cover of the reaction vessel during the measurement process, avoiding the solubility change caused by the leakage of carbon dioxide gas, and can achieve the measurement of solubility at a predetermined temperature and pressure, thereby improving the measurement accuracy. The system design can accurately measure the solubility of the solid phase auxiliary agent in liquid carbon dioxide under high pressure. Compared with traditional measurement methods, the present invention is more accurate and reliable. The design of the present invention focuses on the simplicity of operation, reduces the complexity of the experimental steps, avoids the cumbersome sampling in the traditional method, reduces the complexity of the experimental operation, and makes the solubility measurement more efficient.

[0006] In some embodiments of the present application, the measuring system also includes a first temperature sensor and a first pressure sensor for measuring the temperature and pressure in the reaction vessel, respectively, and a second temperature sensor and a second pressure sensor for measuring the temperature and pressure in the piston container, respectively. The data acquisition and control system is also used to obtain the temperature and pressure in the reaction vessel and the temperature and pressure in the piston container, and judge whether the temperature and pressure in the reaction vessel reach the second temperature and the second pressure. Judge whether the temperature and pressure in the piston container reach the first temperature and the first pressure. The data acquisition and control system is also used to control the first circulating water bath device and the second circulating water bath device, so that the temperature in the reaction vessel and the temperature in the piston container reach the second temperature and the first temperature, respectively. The data acquisition and control system is also used to control the pressure of the plunger pump, so that the liquid carbon dioxide in the top space of the piston container is injected into the reaction vessel, and the volume of water injected into the bottom of the piston container by the plunger pump is collected.

[0007] In some embodiments of the present application, the measurement system also includes a camera device and a visualization window, the visualization window is provided on the container body, and the camera device is used to capture a real-time image of the solid phase auxiliary agent in the reaction vessel through the visualization window. The real-time image includes a first image corresponding to the mixing of the solid phase auxiliary agent and the liquid carbon dioxide and a second image separated from each other. The data acquisition and control system is also used to obtain the temperature and pressure measured by the first temperature sensor and the first pressure sensor at the time point according to the time point captured by the first image. The measurement system also includes a discharge pipe, which is used to connect the container body and discharge the remaining liquid carbon dioxide after a predetermined time period. The data acquisition and control system is also used to calculate the molar amount of gaseous carbon dioxide in the container body according to the obtained temperature and pressure. The data acquisition and control system is also used to obtain the molar amount of liquid carbon dioxide transferred from the top space to the container body according to the calculated molar amount of gaseous carbon dioxide and the molar amount of liquid carbon dioxide discharged.

[0008] In some embodiments of the present application, the separation mechanism includes a placement portion, a connection portion, and a separation rod, wherein the placement portion is used to place the solid phase auxiliary agent. The connection portion is movably connected to the container body. The separation rod is fixed to the connection portion. The separation rod is used to move relative to the reaction container through the connection portion to separate the solid phase auxiliary agent from the liquid carbon dioxide.

[0009] In some embodiments of the present application, the measurement system further includes a delivery pipeline, and the delivery pipeline includes a first delivery pipeline and a second delivery pipeline. The first delivery pipeline includes a first branch pipe and a second branch pipe. The first branch pipe connects the gas supply device and the top space, and the second branch pipe connects the top space and the reaction container. The second delivery pipeline is used to connect the plunger pump and the bottom space.

[0010] In some embodiments of the present application, the first branch pipe is provided with a first needle valve for opening and closing the first branch pipe. The second branch pipe includes a first end and a second end arranged opposite to each other, the first end is connected to the top space, and the second end is connected to the bottom of the reaction container. The first end is provided with a second needle valve for opening and closing the first end, and the second end is provided with a third needle valve for opening and closing the second end.

[0011] In some embodiments of the present application, the discharge pipeline is provided with a fourth needle valve for opening and closing the discharge pipeline.

[0012] In some embodiments of the present application, the measurement system further includes a stirrer, which is disposed in the reaction container and is used to stir the liquid carbon dioxide.

[0013] The second aspect of the present application also provides a solubility measurement method for measuring the solubility of a solid phase auxiliary agent in liquid carbon dioxide. The measurement method is implemented using the aforementioned measurement system, and the measurement method includes: placing the solid phase auxiliary agent in a separation mechanism. The piston container and the reaction container are respectively placed in a first circulating water bath device and a second circulating water bath device. The gas supply device is turned on to inject carbon dioxide into the top space of the piston container until it is liquefied and full. Liquid is injected into the bottom space by a plunger pump so that the liquid carbon dioxide in the top space is injected into the container body of the reaction container. The separation mechanism is extended into the liquid carbon dioxide to mix the solid phase auxiliary agent with the liquid carbon dioxide. After the dissolution equilibrium is reached, the solid phase auxiliary agent on the separation mechanism is separated from the liquid carbon dioxide and left to stand for a predetermined period of time, so that the liquid carbon dioxide attached to the separation mechanism drips to avoid affecting the experimental results. Thereafter, the fourth needle valve is opened to release the carbon dioxide in the reaction container to the outside, and the solid phase auxiliary agent dissolved in the liquid carbon dioxide is precipitated. The solubility of the solid phase auxiliary agent in the liquid carbon dioxide is calculated based on the molar amount of liquid carbon dioxide transmitted from the top space to the container body and the molar amount of the precipitated solid phase auxiliary agent.

[0014] In some embodiments of the present application, the step of determining the molar amount of liquid carbon dioxide transferred from the top space to the container body includes discharging the remaining liquid carbon dioxide after a predetermined time period. A real-time image of the solid phase auxiliary agent in the reaction vessel is captured through a visualization window on the container body, and the real-time image includes a first image corresponding to the separation of the solid phase auxiliary agent and the liquid carbon dioxide from each other. According to the time point at which the first image is captured, the temperature and pressure of the container body measured by the first temperature sensor and the first pressure sensor at the time point are obtained. Based on the acquired temperature and pressure, the molar amount of gaseous carbon dioxide in the container body is calculated. Based on the calculated molar amount of gaseous carbon dioxide and the molar amount of liquid carbon dioxide discharged, the molar amount of liquid carbon dioxide transferred from the top space to the container body is obtained.

[0015] Compared with the prior art, the solubility measurement method provided in the embodiment of the present application is to place a solid phase solvent into a separation mechanism, and extend the separation mechanism into liquid carbon dioxide so that the solid phase auxiliary agent and the liquid carbon dioxide are mixed with each other. After the dissolution equilibrium is reached, the undissolved solid phase auxiliary agent is separated from the liquid carbon dioxide by the separation mechanism. This can eliminate the need to open the lid of the reaction vessel during the measurement process, avoid solubility changes caused by the leakage of carbon dioxide gas, and measure the solubility at a predetermined temperature and pressure, thereby improving the measurement accuracy. The present application can achieve accurate solubility measurement of solid phase auxiliary agents in liquid carbon dioxide under high pressure, and provide real-time visual dissolution process, simplify experimental operations, reduce device costs, and provide reliable data support for research and application in related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of a solubility measurement system according to an embodiment of the present application.

[0017] Figure 2 yes Figure 1 A three-dimensional schematic diagram of the reaction vessel shown.

[0018] Description of main component symbols:

[0019] Measuring system 100; gas supply device 10; piston container 20; top space 21; bottom space 22; piston 23; plunger pump 30; delivery pipeline 40; first circulating water bath device 50; reaction container 60; separation mechanism 61; first pressure sensor 62; first temperature sensor 63; agitator 64; discharge pipeline 65; second circulating water bath device 51; second pressure sensor 231; second temperature sensor 24; data acquisition and control system 70; visualization window 66; camera device 71; separation rod 611; placement part 612; connecting part 613; first delivery pipeline 401; first branch pipe 4011; second branch pipe 4012; second delivery pipeline 402; first needle valve 4013; first end 4021; second end 4022; second needle valve 4023; third needle valve 4024; fourth needle valve 650; The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0021] It should be noted that when an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be a centrally disposed element at the same time. When an element is considered to be "disposed on" another element, it may be directly disposed on the other element or there may be a centrally disposed element at the same time.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0023] At present, most studies focus on the solubility of solid phase additives in supercritical carbon dioxide, and there are a lot of research gaps in the measurement of the solubility of solid phase additives in liquid carbon dioxide. Because the test environment is high pressure, especially when the sample solubility is small, it is difficult to obtain accurate results, and the test method is relatively limited. In the related art, after the sample reaches dissolution equilibrium in liquid carbon dioxide, a portion of the liquid carbon dioxide dissolved with the sample is taken for component analysis. However, there will be temperature / pressure disturbances during the sampling process, causing a portion of the undissolved solid phase additive to enter the sampling container with the flow of liquid carbon dioxide, resulting in untrue and inaccurate test results, and the method is cumbersome, the device is complex, and the cost is high, making it difficult to measure the solubility of the solid phase additive in liquid carbon dioxide under in-situ temperature and pressure conditions. Moreover, when the existing solubility measurement method measures the solubility of the solid phase additive in liquid carbon dioxide under high pressure, it is easily interfered by sampling errors and undissolved solid particles, resulting in inaccurate measurement results. Existing high-pressure solubility measurement devices are often complex in structure, expensive, and difficult to maintain and adjust, which limits their popularity and use in research and industrial applications.

[0024] In view of the above shortcomings, there is an urgent need to develop a new method and system that can realize accurate measurement of the solubility of solid phase additives in liquid carbon dioxide. This method facilitates the acquisition of solubility data of certain solid phase additives in liquid carbon dioxide, which is of great significance for establishing a basic solubility database and provides reliable data support for subsequent theoretical research and industrial applications.

[0025] To this end, the present application embodiment aims to provide a solubility measurement system 100 for measuring the solubility of a solid phase additive in liquid carbon dioxide. Figure 1 and Figure 2 The measuring system 100 includes a gas supply device 10 , a piston container 20 , a plunger pump 30 , a first circulating water bath device 50 , a second circulating water bath device 51 , a reaction container 60 , and a data acquisition and control system 70 .

[0026] The gas supply device 10 is used to provide gaseous carbon dioxide. The piston container 20 includes a cavity and a piston 23 located in the cavity. The piston 23 divides the cavity into a top space 21 and a bottom space 22. The top space 21 is connected to the gas supply device 10 and is used to accommodate the gaseous carbon dioxide transmitted by the gas supply device 10 until it is liquefied and full. The plunger pump 30 is connected to the bottom space 22 and is used to pressurize the top space 21 to a first pressure. When the top space 21 reaches the first pressure, a certain amount of liquid carbon dioxide can be injected into the reaction container. The first circulating water bath device 50 is used to accommodate the piston container 20 and keep the piston container 20 at a first temperature, so that the gaseous carbon dioxide in the top space 21 is converted into liquid carbon dioxide at a first pressure and a first temperature. The piston container 20 can be kept at a certain temperature condition to maintain the temperature of the liquid carbon dioxide.

[0027] The reaction vessel 60 includes a container body and a separation mechanism 61. The container body is connected to the top space 21 and is used to accommodate liquid carbon dioxide transmitted from the top space 21. The separation mechanism 61 can be movably arranged on the container body, and the separation mechanism 61 is used to carry a solid-phase auxiliary agent and mix or separate the solid-phase auxiliary agent and liquid carbon dioxide. By setting the separation mechanism 61, the operator does not need to open the reaction vessel 60, avoiding fluctuations in temperature or pressure inside the reaction vessel 60, which affects the measurement of the solubility of the solid-phase auxiliary agent in liquid carbon dioxide. The second circulating water bath device 51 is used to accommodate the reaction vessel 60 and maintain the reaction vessel 60 at a second temperature, so that the solid-phase auxiliary agent is dissolved in the liquid carbon dioxide at a second pressure and a second temperature. After a predetermined period of time when the solid-phase auxiliary agent and the liquid carbon dioxide are separated from each other, the solid-phase auxiliary agent dissolved in the liquid carbon dioxide precipitates. Optionally, the reaction vessel 60 is a fully visible autoclave, specifically, the fully visible autoclave has a fully visible sapphire glass. Optionally, the fully visible autoclave can be replaced with a semi-visual autoclave, that is, only a window is required to observe the position of the separation mechanism 61.

[0028] The data acquisition and control system 70 is used to calculate the solubility of the solid phase auxiliary agent in the liquid carbon dioxide according to the molar amount of the liquid carbon dioxide transferred from the top space 21 to the container body and the molar amount of the precipitated solid phase auxiliary agent.

[0029] See also Figure 1 and Figure 2In one embodiment of the present application, the measurement system 100 further includes a first temperature sensor 63 and a first pressure sensor 62, which are respectively used to measure the temperature and pressure in the reaction vessel 60. The second temperature sensor 24 and the second pressure sensor 231 are respectively used to measure the temperature and pressure in the piston container 20 to determine the temperature and pressure of the liquid carbon dioxide, and at the same time, the amount of liquid carbon dioxide delivered by the piston container 20 to the reaction container 60 can be measured. The data acquisition and control system 70 is also used to obtain the temperature and pressure in the reaction container 60 and the temperature and pressure in the piston container 20, and to determine whether the temperature and pressure in the reaction container 60 reach the second temperature and the second pressure, so as to determine the specific temperature and pressure of the solid phase auxiliary agent dissolved in the liquid carbon dioxide. Determine whether the temperature and pressure in the piston container 20 reach the first temperature and the first pressure. The data acquisition and control system 70 is also used to control the first circulating water bath device 50 and the second circulating water bath device 51. Thereby, the temperature in the reaction container 60 and the temperature in the piston container 20 reach the second temperature and the first temperature respectively.

[0030] In one embodiment of the present application, the measurement system 100 also includes a camera 71 and a visualization window 66, and the visualization window 66 is provided on the container body. The camera 71 is used to capture a real-time image of the solid phase auxiliary agent in the reaction vessel 60 through the visualization window 66, and the real-time image includes a first image corresponding to the solid phase auxiliary agent and the liquid carbon dioxide when they are mixed with each other and a second image when they are separated from each other. Because when the solid phase auxiliary agent is separated from the liquid carbon dioxide, the carbon dioxide in the reaction vessel 60 has two phases. Mainly gaseous carbon dioxide and liquid carbon dioxide. By calculating the specific molar amount of the two-phase carbon dioxide, the solubility of the solid phase auxiliary agent in liquid carbon dioxide is calculated. Therefore, the visualization window 66 and the camera 71 can determine the specific time when the separation mechanism 61 separates the solid phase auxiliary agent and the liquid carbon dioxide and the temperature and pressure conditions in this state, so that the solubility of the solid phase auxiliary agent can be calculated without opening the reaction vessel 60. The data acquisition and control system 70 is also used to obtain the temperature and pressure measured by the first temperature sensor 63 and the first pressure sensor 62 at the time point according to the time point captured by the second image.

[0031] In one embodiment of the present application, the measurement system 100 also includes a discharge pipe 65, which is used to connect the container body and discharge the carbon dioxide in the reaction vessel to the outside after a predetermined time period. The data acquisition and control system 70 is also used to calculate the molar amount of gaseous carbon dioxide in the container body according to the acquired temperature and pressure. The data acquisition and control system 70 is also used to obtain the molar amount of liquid carbon dioxide transmitted from the head space 21 to the container body according to the molar amount of gaseous carbon dioxide calculated by the ideal gas state equation and the molar amount of liquid carbon dioxide discharged according to the Bernoulli equation.

[0032] In one embodiment of the present application, the separation mechanism 61 includes a placement portion 612, a connection portion 613 and a separation rod 611. The placement portion 612 is used to place the solid-phase auxiliary agent. Optionally, the placement portion 612 can be spoon-shaped, hook-shaped or rod-shaped. The connection portion 613 is movably connected to the container body. The separation rod 611 is fixed to the connection portion 613, and the separation rod 611 is used to move relative to the reaction vessel 60 through the connection portion 613 to separate the solid-phase auxiliary agent and the liquid carbon dioxide from each other. The connection portion 613 can facilitate the separation and connection between the separation rod 611 and the reaction vessel 60. When the solid-phase auxiliary agent and the liquid carbon dioxide need to be mixed, the separation rod 611 can be extended into the liquid carbon dioxide. When the solid-phase auxiliary agent and the liquid carbon dioxide are dissolved, the separation rod 611 can be moved relative to the reaction vessel 60 through the connection portion 613 to separate the solid-phase auxiliary agent from the liquid carbon dioxide. Optionally, the connection part 613 is threadedly connected to the reaction container 60. Through the threaded connection between the connection part 613 and the reaction container 60, while ensuring the sealing of the reaction container 60, the separation rod 611 can be moved relative to the reaction container 60 by rotating the connection part 613. The operation is simple, and the solid phase auxiliary agent on the placement part 612 can be extended into and separated from the liquid carbon dioxide. Optionally, the separation mechanism 61 can be slidably connected or elastically connected to the reaction container 60.

[0033] In one embodiment of the present application, a delivery pipeline 40 is also included, and the delivery pipeline 40 includes a first delivery pipeline 401 and a second delivery pipeline 402. The first delivery pipeline 401 includes a first branch pipe 4011 and a second branch pipe 4012, the first branch pipe 4011 connects the gas supply device 10 and the top space 21, and the second branch pipe 4012 connects the top space 21 and the reaction container 60. The second delivery pipeline 402 is used to connect the plunger pump 30 and the bottom space 22. By setting the delivery pipeline 40, it is convenient to control the transmission of carbon dioxide.

[0034] In one embodiment of the present application, the first branch pipe 4011 is provided with a first needle valve 4013 for opening and closing the first branch pipe 4011. The second branch pipe 4012 includes a first end 4021 and a second end 4022 arranged opposite to each other, the first end 4021 is connected to the top space 21, and the second end 4022 is connected to the bottom of the reaction vessel 60. The first end 4021 is provided with a second needle valve 4023 for opening and closing the first end 4021, and the second end 4022 is provided with a third needle valve 4024 for opening and closing the second end 4022. By opening and closing the first needle valve 4013, the amount of carbon dioxide entering the top space 21 can be controlled. By controlling the second needle valve 4023, the amount of liquid carbon dioxide entering the reaction vessel 60 can be controlled. By controlling the third needle valve 4024, the liquid carbon dioxide can be stopped from entering the reaction vessel 60.

[0035] In one embodiment of the present application, the exhaust pipe 65 is provided with a fourth needle valve 650 for opening and closing the exhaust pipe 65. Carbon dioxide can be exhausted to the outside.

[0036] In one embodiment of the present application, the measuring system further comprises a stirrer 64, which is disposed in the reaction container 60 and is used to stir the liquid carbon dioxide. The stirrer 64 is provided to fully mix the solid phase auxiliary agent and the liquid carbon dioxide.

[0037] The second aspect of the present application also provides a solubility measurement method for measuring the solubility of a solid phase additive in liquid carbon dioxide, and the measurement method is implemented using the aforementioned measurement system 100. According to different requirements, the order of certain steps or sub-steps of the measurement method can be changed, and certain steps or sub-steps can be omitted or combined. The measurement method includes:

[0038] Step 1: Place the solid phase additive into the separation mechanism 61.

[0039] In some embodiments, the solid phase auxiliary agent is dried and placed into the separation mechanism 61, and the drying time is 24-48 hours.

[0040] Step 2: Place the piston container 20 and the reaction container 60 in the first circulating water bath device 50 and the second circulating water bath device 51 respectively. The temperatures of the piston container 20 and the reaction container 60 can be kept stable.

[0041] Step 3: Open the gas supply device 10 and inject gaseous carbon dioxide into the top space 21 until it is filled with liquefied carbon dioxide.

[0042] Step 4: inject liquid into the bottom space 22 through the plunger pump 30 so that the liquid carbon dioxide in the top space 21 is injected into the container body of the reaction container 60 .

[0043] Step 5: Extend the separation mechanism 61 into the liquid carbon dioxide to mix the solid phase additive with the liquid carbon dioxide.

[0044] In some embodiments, the solid phase aid is fully stirred and dissolved using a stirrer 64 , and the stirring rate of the stirrer 64 is 600 rpm. To ensure sufficient dissolution, the stirring time is 120 h.

[0045] Step 6: After dissolution equilibrium is reached, the solid phase auxiliary agent on the separation mechanism 61 is separated from the liquid carbon dioxide and left to stand for a predetermined period of time. Then, the fourth needle valve 650 is opened to discharge the carbon dioxide in the reaction container, and the solid phase auxiliary agent dissolved in the liquid carbon dioxide is precipitated.

[0046] In some embodiments, the predetermined time period is 24 h-48 h. In some optional embodiments, the standing time can be 24 h, 36 h and 48 h.

[0047] Step 7: Calculate the solubility of the solid phase additive in the liquid carbon dioxide according to the molar amount of the liquid carbon dioxide transferred from the top space 21 to the container body and the molar amount of the precipitated solid phase additive.

[0048] In one embodiment of the present application, the step of determining the molar amount of liquid carbon dioxide transferred from the top space 21 to the container body includes discharging the remaining liquid carbon dioxide after a predetermined time period. A real-time image of the solid phase auxiliary agent in the reaction vessel 60 is captured through a visualization window 66 on the container body, and the real-time image includes a first image corresponding to the separation of the solid phase auxiliary agent and the liquid carbon dioxide from each other. According to the time point at which the first image is captured, the temperature and pressure of the container body measured by the first temperature sensor 63 and the first pressure sensor 62 at the time point are obtained. Based on the acquired temperature and pressure, the molar amount of gaseous carbon dioxide in the container body is calculated. Based on the calculated molar amount of gaseous carbon dioxide and the molar amount of discharged liquid carbon dioxide, the molar amount of liquid carbon dioxide transferred from the top space 21 to the container body is obtained.

[0049] In some embodiments, the interior of the reaction container 60 is repeatedly rinsed with a solvent in which the solid phase additive is easily dissolved, and a certain amount of solvent in which the solid phase additive is dissolved is taken, and the concentration c of the solid phase additive in the solvent is measured by ICP-OES (inductively coupled plasma emission spectrometry). x , and by the formula Calculate the molar amount of dissolved solid phase additive. Where n x is the molar amount of the solid phase additive dissolved in the liquid carbon dioxide in the reaction vessel 60, c x is the concentration of solid phase additive in the solvent, V x M is the volume after adding solvent to dissolve the solid phase additive. x is the molar mass of the solid phase additive.

[0050] The solubility measurement method provided in the present application converts gaseous carbon dioxide into liquid carbon dioxide through a plunger pump 30 and a piston container 20, and by placing a solid phase solvent into a separation mechanism, and extending the separation mechanism into liquid carbon dioxide, so that the solid phase auxiliary agent and the liquid carbon dioxide are mixed with each other, and the undissolved solid phase auxiliary agent is separated from the liquid carbon dioxide by the separation mechanism after the dissolution equilibrium, so that the cover of the reaction vessel does not need to be opened during the measurement process, and the solubility change caused by the leakage of carbon dioxide gas can be avoided. The solubility at a predetermined temperature and pressure can be measured, and the measurement accuracy can be improved. At the same time, the solubility of the solid phase auxiliary agent in liquid carbon dioxide can be accurately measured under a high pressure environment. By measuring the real-time pressure and temperature of the piston container 20 and the reaction container 60, and using a water bath device to maintain the temperature of the piston container 20 and the reaction container 60, and measuring the amount of liquid carbon dioxide entering at the same time, the solubility of the solid phase auxiliary agent in liquid carbon dioxide can be calculated. Compared with the traditional measurement method, the present application is more accurate and reliable, easy to operate, reduces the complexity of the experimental steps, avoids the cumbersome sampling in the traditional method, reduces the complexity of the experimental operation, and makes the solubility measurement more efficient. By measuring the solubility of different substances (such as impurities or additives in crude oil) in liquid carbon dioxide, the recovery rate and economic benefits can be improved; the dissolution behavior of various minerals, salts, and additives in liquid carbon dioxide is studied to help prevent corrosion and scaling of pipelines and equipment. In one embodiment of the present application, when the solubility of the solid phase additive is large, the mass difference before and after the solid phase additive is dissolved is measured to calculate the molar amount of the solid phase additive dissolved in the reaction vessel; when the solubility of the solid phase additive is small, the reaction vessel is rinsed with a solvent that can dissolve the solid phase additive, and a portion of the solvent that dissolves the solid phase additive is taken to measure the molar amount of the solid phase additive dissolved in the reaction vessel. Optionally, when the solubility of the solid phase additive is small, the concentration of the solid phase additive can be determined using ICP-OES technology.

[0051] The following is a detailed description of the calculation process of the solubility of the solid phase additive in liquid carbon dioxide:

[0052] (Formula 1);

[0053] Among them, n 1 is the molar amount of liquid carbon dioxide in the piston container 20; ρ 1 V is the density of carbon dioxide before the piston container injects it into the reaction container; 1 M is the volume of the piston container 20; CO2 is the molar mass of carbon dioxide; n 2 V is the molar amount of liquid carbon dioxide remaining in the piston container 20; 2 is the volume of the remaining amount of liquid carbon dioxide in the piston container 20; 2 is the density of carbon dioxide after the piston container injects it into the reaction container; n 3is the molar amount of liquid carbon dioxide injected into the reaction vessel 60 by the piston container 20;

[0054] When the solid phase auxiliary agent and the liquid carbon dioxide in the reaction container 60 are dissolved, the gaseous carbon dioxide (n G ) and liquid carbon dioxide (n L ) two phases, solved by the following formula;

[0055] (Formula 2);

[0056] (Formula 3);

[0057] (Formula 4);

[0058] (Formula 5);

[0059] Wherein, P is the real-time kettle pressure of the reaction vessel 60 when the dissolution is finished; T is the real-time kettle temperature of the reaction vessel 60 when the dissolution is finished; V G V is the volume of gaseous carbon dioxide in the reaction vessel 60; L is the volume of liquid carbon dioxide in the reaction vessel 60; Z is the compression factor; R is the universal gas constant; ρ L V is the density of liquid carbon dioxide in the reaction vessel 60; r is the volume of the reaction vessel 60; the molar amount of the solid phase additive dissolved in the liquid carbon dioxide in the reaction vessel 60 is n x :

[0060] (Formula 6);

[0061] The solubility of the solid phase additive in liquid carbon dioxide is χ:

[0062] (Formula 7);

[0063] Among them, c x is the concentration of solid phase additive in the solvent; V x M is the volume after adding solvent to dissolve the solid phase additive; x is the molar mass of the solid phase additive; n L is the molar amount of liquid carbon dioxide that is compatible with the solid phase auxiliary agent in the reaction vessel 60.

[0064] The solubility measurement system 100 provided in the embodiment of the present application specifically includes the following steps:

[0065] Step S1, after drying the solid phase additive for 24 hours, put it into a nylon bag and hang it on the placement part 612 of the separation mechanism 61;

[0066] Step S2, placing the piston container 20 and the reaction container 60 in the first circulating water bath device 50 and the second circulating water bath device 51 respectively, and cooling the two containers to the same target temperature through the first circulating water bath device 50 and the second circulating water bath device 51;

[0067] Step S3, open the first needle valve 4013 and the second needle valve 4023, and the gas supply device 10 injects gaseous carbon dioxide into the top space 21 of the piston container 20 until the liquefied carbon dioxide is fully filled, and then close the first needle valve 4013 and the second needle valve 4023;

[0068] Step S4, opening the second needle valve 4023 and the third needle valve 4024, injecting liquid into the bottom space 22 of the piston container 20 for pressurization through the plunger pump 30, and injecting the liquid carbon dioxide in the top space 21 into the reaction container 60. At this time, the plunger pump 30 can collect the volume of water injected into the lower part of the piston container 20;

[0069] Step S5, when the liquid carbon dioxide in the reaction container 60 reaches the target amount, stop injecting, close the third needle valve 4024, immerse the nylon bag on the placement part 612 of the separation rod 611 in the liquid carbon dioxide by rotating the connecting part 613, use the stirrer 64 to set the stirring rate and stirring time, and fully dissolve the solid phase auxiliary agent;

[0070] Step S6, after reaching the dissolution equilibrium, the nylon bag on the placement part 612 of the separation rod 611 is separated from the liquid surface of the liquid carbon dioxide by rotating the connection part 613, and the bag is left to stand for 24h-48h, so that the liquid carbon dioxide attached to the nylon bag can be separated from the bag body due to gravity;

[0071] Step S7, open the fourth needle valve 650 to discharge the liquid carbon dioxide through the discharge pipe 65, use the solid phase auxiliary agent and measure the molar amount of the solid phase auxiliary agent dissolved in the reaction container 60 to calculate the solubility of the solid phase auxiliary agent in the liquid carbon dioxide.

[0072] The above-mentioned solubility measurement system is further described below through specific examples.

[0073] Example 1

[0074] Step 1: Place the NaCl particles in an oven for 24 hours. After drying, place 1.0 g of the NaCl particles in a nylon bag with a pore size of 350 meshes. The nylon material will not be corroded by liquid carbon dioxide. The nylon is sealed and hung on the placement part 612 of the separation mechanism 61. The connection part 613 is rotated to place the nylon bag at the top.

[0075] Step 2: Wash, dry and seal the reaction container 60 with a volume of 100 mL and the piston container 20 with a volume of 100 mL, and place them in the first circulating water bath device 50 and the second circulating water bath device 51, respectively, and set the temperature of the water bath to 10° C. After the temperature of the device is stable, connect the carbon dioxide cylinder to the upper valve of the piston container 20, open the first needle valve 4013 and the second needle valve 4023, until the gaseous carbon dioxide is filled, and the pressure of the gaseous carbon dioxide is 5.6 MPa;

[0076] Step 3, connect the plunger pump 30 and the lower valve of the piston container 20 through the second delivery pipeline 402, set the pressure to 7.2Mpa, so as to use the water pressure to continuously inject the liquid carbon dioxide in the piston container 20 from the piston container 20 into the reaction container 60, slowly open the third needle valve 4024, and continuously inject liquid carbon dioxide after reaching the carbon dioxide liquefaction pressure (about 4.5 MPa). When the water injection volume of the plunger pump 30 reaches 75 mL, stop injecting and close the needle valve. At this time, the liquid carbon dioxide does not immerse the nylon bag;

[0077] Step 4: The nylon bag is immersed in liquid carbon dioxide by rotating the connection part 613, and the stirrer 64 is turned on and the stirring rate is set to 600 rpm. To ensure full dissolution, the mixture is placed for 120 hours, at which time the temperature of the reactor is 10.2°C and the pressure is 4.67 MPa;

[0078] Step 5: After the dissolution is completed, the nylon bag is separated from the liquid carbon dioxide surface by rotating the connecting portion 613, the magnetic stirrer 64 is turned off, and the mixture is allowed to stand for 24 hours to allow the liquid carbon dioxide attached to the nylon bag to drip off.

[0079] Step 6. Finally, slowly open the fourth needle valve 650, slowly release the gas to allow the dissolved NaCl to be taken out by the carbon dioxide. After the release is completed, disassemble the reactor, use a pipette to add 5 mL of deionized water to repeatedly rinse the NaCl precipitated on the inner wall surface of the reaction vessel 60. Considering that the solubility of NaCl in liquid carbon dioxide is low, deionized water is not repeatedly added. Instead, a dropper is used to repeatedly rinse the inner wall of the reactor with the 5 mL of deionized water.

[0080] Step 7. After rinsing, sample 4 mL of NaCl solution and use ICP-OES equipment (with a determination accuracy of 0.05 mg / L) to determine the Na element concentration to be 2.974 mg / L. The specific parameters are shown in Table 1 below.

[0081]

[0082] It can be seen that the present application provides a solubility measurement system and method, which can realize accurate solubility measurement of solid phase additives in liquid carbon dioxide under high pressure environment, and provide real-time visualization of dissolution process, simplify experimental operation, reduce device cost, and provide reliable data support for research and application in related fields. 2 This solves the problem of solubility of solid phase additives in liquid CO under high pressure. 2 When measuring the solubility in a liquid, it is susceptible to sampling errors and interference from undissolved solid particles, resulting in inaccurate measurement results. This solves the problem that existing high-pressure solubility measurement devices are often complex in structure, expensive, and difficult to maintain and adjust, which limits their popularity and use in research and industrial applications.

[0083] At the same time, the solubility measurement method provided in this application can also be used in the following aspects:

[0084] (1) For Carbon Capture and Storage (CCS): Measuring the solubility of minerals, salts, and additives in liquid CO2 helps evaluate chemical reactions and mineral changes after CO2 injection, ensuring the stability and safety of storage.

[0085] (2) Carbon dioxide flooding technology (CO 2 -EOR): by measuring the presence of different substances (such as impurities or additives in crude oil) in liquid CO 2 The solubility of various minerals, salts and additives in liquid carbon dioxide can be studied to improve the recovery rate and economic benefits; the dissolution behavior of various minerals, salts and additives in liquid carbon dioxide can be studied to help prevent corrosion and scaling of pipelines and equipment.

[0086] (3) Drug development and analysis: Measure the solubility of drug ingredients in liquid carbon dioxide, study their solubility, stability and release behavior, and optimize drug formulations and delivery systems.

[0087] (4) Development of new materials: By studying the solubility and dissolution behavior of various materials (such as polymers, nanomaterials, and composite materials) in liquid carbon dioxide, the synthesis and processing technology of materials can be optimized.

[0088] (5) Extraction: Measure the solubility of chemical components in liquid carbon dioxide, optimize the carbon dioxide extraction process, and improve extraction efficiency and product quality.

[0089] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A solubility measurement system for measuring the solubility of a solid phase additive in liquid carbon dioxide, characterized in that: The measurement system comprises: A gas supply device, used for providing gaseous carbon dioxide; A piston container, comprising a cavity and a piston located in the cavity, wherein the piston divides the cavity into a top space and a bottom space, wherein the top space is connected to the gas supply device and is used to accommodate the gaseous carbon dioxide transmitted by the gas supply device until it is liquefied and filled; a plunger pump connected to the bottom space and used to pressurize the top space to a first pressure; a first circulating water bath device, for accommodating the piston container and maintaining the piston container at a first temperature, so that the gaseous carbon dioxide in the head space is converted into liquid carbon dioxide at the first pressure and the first temperature; A reaction container, comprising a container body and a separation mechanism, wherein the container body is connected to the top space and is used to accommodate the liquid carbon dioxide transmitted from the top space, the separation mechanism is movably arranged on the container body, the separation mechanism is used to carry the solid phase auxiliary agent and mix or separate the solid phase auxiliary agent and the liquid carbon dioxide, the separation mechanism comprises a placement portion, a connection portion and a separation rod, the placement portion is used to place the solid phase auxiliary agent, the connection portion is movably connected to the container body, the separation rod is fixed to the connection portion, and the separation rod is used to move relative to the reaction container through the connection portion to separate the solid phase auxiliary agent from the liquid carbon dioxide; a second circulating water bath device, for accommodating the reaction container and maintaining the reaction container at a second temperature, so that the solid phase auxiliary agent is dissolved in the liquid carbon dioxide at a second pressure and the second temperature, and after a predetermined period of time when the solid phase auxiliary agent and the liquid carbon dioxide are separated from each other, the carbon dioxide in the container body is discharged to precipitate the solid phase auxiliary agent dissolved in the liquid carbon dioxide; A data acquisition and control system is used to calculate the solubility of the solid phase auxiliary agent in the liquid carbon dioxide based on the molar amount of the liquid carbon dioxide transferred from the top space to the container body and the molar amount of the precipitated solid phase auxiliary agent.

2. The solubility measurement system according to claim 1, characterized in that: The measuring system further comprises: A first temperature sensor and a first pressure sensor, used to measure the temperature and pressure in the reaction container respectively; A second temperature sensor and a second pressure sensor, used to measure the temperature and pressure in the piston container respectively; The data acquisition and control system is also used to obtain the temperature and pressure in the reaction container and the temperature and pressure in the piston container, to determine whether the temperature and pressure in the reaction container reach the second temperature and the second pressure, and to determine whether the temperature and pressure in the piston container reach the first temperature and the first pressure. The data acquisition and control system is also used to control the first circulating water bath device and the second circulating water bath device, so that the temperature in the reaction container and the temperature in the piston container reach the second temperature and the first temperature respectively.

3. The solubility measurement system according to claim 2, characterized in that: The measurement system further includes a camera device and a visualization window, wherein the visualization window is provided on the container body, the camera device is used to capture a real-time image of the solid phase auxiliary agent in the reaction container through the visualization window, the real-time image includes a first image corresponding to when the solid phase auxiliary agent and the liquid carbon dioxide are mixed with each other and a second image when they are separated from each other, and the data acquisition and control system is further used to obtain the temperature and pressure measured by the first temperature sensor and the first pressure sensor at the time point when the second image is captured; The measuring system further comprises a discharge pipe, the discharge pipe being used to be connected to the container body and discharge the liquid carbon dioxide after the predetermined period of time; The data acquisition and control system is also used to calculate the molar amount of gaseous carbon dioxide in the container body based on the acquired temperature and pressure. The data acquisition and control system is also used to obtain the molar amount of the liquid carbon dioxide transferred from the top space to the container body based on the calculated molar amount of gaseous carbon dioxide and the molar amount of the discharged liquid carbon dioxide.

4. The solubility measurement system according to claim 1, characterized in that: It also includes a delivery pipeline, the delivery pipeline includes a first delivery pipeline and a second delivery pipeline, the first delivery pipeline includes a first branch pipe and a second branch pipe, the first branch pipe is connected to the gas supply device and the top space, and the second branch pipe is connected to the top space and the reaction container; The second delivery pipeline is used to connect the plunger pump and the bottom space.

5. The solubility measurement system according to claim 4, characterized in that: The first branch pipe is provided with a first needle valve for opening and closing the first branch pipe; The second branch pipe comprises a first end and a second end which are arranged opposite to each other, the first end is connected to the top space, and the second end is connected to the bottom of the reaction container; The first end is provided with a second needle valve for opening and closing the first end, and the second end is provided with a third needle valve for opening and closing the second end.

6. The solubility measurement system according to claim 3, characterized in that: The discharge pipeline is provided with a fourth needle valve for opening and closing the discharge pipeline.

7. The solubility measurement system according to claim 1, characterized in that: The measuring system further comprises: The stirrer is arranged in the reaction container and is used for stirring the liquid carbon dioxide.

8. A solubility measurement method for measuring the solubility of a solid phase additive in liquid carbon dioxide, characterized in that: The measuring method is implemented by using the solubility measuring system according to any one of claims 1 to 5, and the measuring method comprises: placing a solid phase auxiliary agent into the separation mechanism; placing the piston container and the reaction container in the first circulating water bath device and the second circulating water bath device respectively; Opening the gas supply device to inject gaseous carbon dioxide into the head space; Injecting liquid into the bottom space by the plunger pump, so that the gaseous carbon dioxide in the top space is converted into liquid carbon dioxide and injected into the container body of the reaction container; Extending the separation mechanism into liquid carbon dioxide to allow the solid phase auxiliary agent and the liquid carbon dioxide to mix with each other; After dissolution equilibrium is reached, the solid phase auxiliary agent on the separation mechanism is separated from the liquid carbon dioxide and left to stand for a predetermined period of time, so that at least a portion of the liquid carbon dioxide in the container body is converted into gaseous carbon dioxide, so that the solid phase auxiliary agent dissolved in the liquid carbon dioxide is precipitated; The solubility of the solid phase auxiliary agent in the liquid carbon dioxide is calculated according to the molar amount of the liquid carbon dioxide transferred from the head space to the container body and the molar amount of the precipitated solid phase auxiliary agent.

9. The solubility measurement method according to claim 8, characterized in that: The step of determining the molar amount of the liquid carbon dioxide transferred from the head space to the container body comprises: exhausting the liquid carbon dioxide after the predetermined period of time; capturing a real-time image of the solid phase auxiliary agent in the reaction container through a visualization window on the container body, wherein the real-time image includes a first image corresponding to when the solid phase auxiliary agent and the liquid carbon dioxide are separated from each other; According to the time point at which the first image is captured, acquiring the temperature and pressure of the container body measured by the first temperature sensor and the first pressure sensor at the time point; Calculating the molar amount of the gaseous carbon dioxide in the container body and the molar amount of the liquid carbon dioxide according to the acquired temperature and pressure; The molar amount of the liquid carbon dioxide transferred from the head space to the container body is obtained according to the calculated molar amount of the gaseous carbon dioxide and the molar amount of the liquid carbon dioxide.

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