Device and method for measuring carbon sequestration rate and reaction rate of co2-water-rock mineralization reaction

Abstract

The present application belongs to the technical field of carbon sequestration, and particularly relates to a measuring device and method for carbon sequestration rate and reaction rate of CO2-water-rock mineralization reaction. The measuring device comprises a carbon dioxide gas source, a gas buffer cylinder, a metering pump, an electric heating bin, a data acquisition card for data acquisition, a readout display for data processing and display, and a reaction pool and a reference pool in the electric heating bin and a differential pressure gauge. The measuring method based on the measuring device measures the pressure difference of the two reaction pools and the reference pool by using the differential pressure gauge, can accurately measure the small pressure change under high pressure, obtain the real-time consumption data of CO2, improve the measurement accuracy, and make the measurement result more reliable. The required amount of mineral powder is less, the pressure in the reaction pool is higher, and the pressure difference before and after the reaction is very small, and the conventional pressure sensor will bring large error when measuring the pressure change. The carbon sequestration rate and CO2 reaction rate in the mineralization reaction process are monitored online, and the carbon dioxide mineralization rate can be monitored in real time.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of carbon sequestration, and particularly relates to a device and method for measuring the carbon sequestration rate and reaction rate of CO2-water-rock mineralization reaction. BACKGROUND

[0002] The principle of carbon dioxide mineralization utilization is to react carbon dioxide with alkaline minerals to generate carbonate minerals. This reaction requires certain temperature and pressure conditions, usually above 200 DEG C and above 10 MPa. The products of the mineralization reaction are mainly calcium carbonate, magnesium carbonate and other minerals, which have stability and chemical inertness and can store carbon dioxide for a long time. The essence of CO2 mineralization is to simulate the chemical weathering process of natural rocks in nature, and to mineralize CO2 into stable solid carbonates by using minerals containing calcium and magnesium elements, so as to realize the emission reduction of CO2.

[0003] The advantages of carbon dioxide mineralization utilization are various. First, carbon dioxide mineralization utilization is a new carbon dioxide emission reduction technology, which can convert carbon dioxide into stable minerals for long-term storage and utilization. Secondly, it can reduce the emission of carbon dioxide, reduce the concentration of greenhouse gases and alleviate the impact of climate change. In addition, carbon dioxide mineralization utilization can also provide a new way for the development and utilization of mineral resources, promote economic development in the future, and carbon dioxide mineralization utilization technology will be more widely applied and popularized to create a better future for mankind.

[0004] At present, the research on carbon dioxide mineralization reaction mainly focuses on analyzing the amount of mineralization products generated after mineralization reaction, and calculating the carbon sequestration amount and carbon dioxide sequestration amount. However, the above determination method has certain defects, which cannot accurately calculate the amount of carbon dioxide consumed in the mineralization reaction, mainly in the following aspects:

[0005] First, carbon dioxide is dissolved in water, and the amount of carbon dioxide consumed calculated by the traditional method does not exclude the influence of the part of carbon dioxide dissolved in water, which affects the accuracy of the calculation results;

[0006] Second, for the measurement of CO2 mineralization consumption, the existing volume method is based on the typical chemical reaction equation, without considering the real reaction process and reaction degree, and the accuracy of CO2 mineralization amount estimation needs to be discussed. In summary, considering the complexity of real reaction and the non-steady state characteristics of CO2 mineralization process, it is difficult to explore the real-time mineralization reaction process and accurately evaluate the CO2 mineralization consumption;

[0007] Third, when the traditional method uses a pressure sensor to measure pressure, the pressure sensor itself will produce a larger error when the pressure change is small, thereby affecting the accuracy of the measurement results;

[0008] Fourthly, the traditional method cannot monitor the carbon fixation rate and reaction rate in the mineralization reaction process online, and has the disadvantages of complicated determination steps, inconvenient operation, and large test workload. SUMMARY

[0009] In order to overcome the deficiencies in the prior art, the purpose of the present application is to provide a CO2-water-rock mineralization reaction carbon fixation rate and reaction rate measuring device and method. The measuring device is simple and effective, does not require continuous sampling, and minimizes the interference of the test instrument itself on the test results. The measuring device maintains airtightness throughout the measurement process, improves data accuracy, simplifies the steps of the measurement method, and effectively reduces the workload.

[0010] To achieve the above purpose, the present application adopts the following technical solutions:

[0011] A CO2-water-rock mineralization reaction carbon fixation rate and reaction rate measuring device, the measuring device comprising a carbon dioxide gas source, a sixth valve, a gas buffer cylinder, a seventh valve, a metering pump, an eighth valve, an electric heating bin, and a data acquisition card for data acquisition, a readout display for data processing and display; the electric heating bin is provided with a placement table, a reaction pool, a reference pool, a third valve, a filter I, a differential pressure gauge, a filter II, a fifth valve, and a fourth valve. The carbon dioxide gas source, the sixth valve, the gas buffer cylinder, the seventh valve, the metering pump, and the eighth valve are connected in sequence through a gas pipeline, the gas pipeline downstream of the eighth valve is divided into three parallel gas branch pipelines: pipeline I, pipeline II, and pipeline V, the first valve is arranged on the pipeline I, the second valve is arranged on the pipeline II, and the pipeline V is connected with a vacuum pump and provided with a ninth valve. After the carbon dioxide gas is output from the carbon dioxide gas source, it passes through the sixth valve, the gas buffer cylinder, the seventh valve, the metering pump, and the eighth valve in sequence, and then enters the reaction pool and the reference pool in the electric heating bin through the parallel first valve and second valve respectively, the carbon dioxide gas flowing through the first valve enters the reaction pool through the pipeline I, and the carbon dioxide gas flowing through the second valve enters the reference pool through the pipeline II; the vacuum pump draws vacuum in the reference pool and the reaction pool in the electric heating bin through a pipeline, so that the reaction pool and the reference pool are in a vacuum state before use, then the vacuum pump and the ninth valve are closed, and the carbon dioxide gas source inputs carbon dioxide into the reaction pool and the reference pool through the gas pipeline.

[0012] The two same reaction kettles are placed on the placing table, wherein the reaction kettle provided with the pressure sensor is a reaction pool, which is internally provided with pure water and a small amount of mineral powder, and the other reaction kettle is a reference pool, which is internally provided with pure water. The pipeline I and the pipeline II are communicated through the pipeline III, so that the reaction pool and the reference pool are also communicated through the pipeline III; the pipeline III is provided with a third valve, a filter I, a differential pressure meter, a filter II and a fifth valve. From the connection position of the pipeline III and the pipeline I, the third valve, the filter I, the differential pressure meter, the filter II and the fifth valve are sequentially arranged to the connection position of the pipeline III and the pipeline II. In addition, the pipeline IV is arranged in parallel with the differential pressure meter, one end of the pipeline IV is connected with the pipeline between the third valve and the filter I, the other end of the pipeline IV is connected with the pipeline between the filter II and the fifth valve, and the fourth valve is arranged on the pipeline IV. Thus, when the fourth valve is closed and the third valve and the fifth valve are opened, the carbon dioxide gas flowing through the first valve 1 flows into the reaction pool and the third valve respectively, the carbon dioxide gas flowing through the third valve then flows through the filter I and reaches the differential pressure meter, and the carbon dioxide gas flowing through the second valve flows into the reference pool and the fifth valve respectively, the carbon dioxide gas flowing through the fifth valve then flows through the filter II and reaches the differential pressure meter. At this time, the differential pressure meter measures the pressure difference of the carbon dioxide at both ends. When the fourth valve, the third valve and the fifth valve are opened together, the carbon dioxide gas flowing through the third valve is directly communicated with the carbon dioxide gas flowing through the fifth valve through the pipeline IV. At this time, the pressure difference of the carbon dioxide at both ends of the differential pressure meter is 0 due to the parallel connection.

[0013] The reaction pool is further provided with an exhaust valve and a liquid level meter. The exhaust valve prevents the reaction kettle from exploding due to excessive pressure. The liquid level meter displays the water level of the pure water in the reaction pool.

[0014] Preferably, the volume of the reaction pool and the reference pool is 1-50 L, more preferably 1 L.

[0015] Preferably, the data acquisition card is used to collect the readings of the pressure sensor and the differential pressure meter, the flow readings of the metering pump, and transmit the collected readings to the reading display.

[0016] Preferably, the heating temperature of the electric heating bin ranges from 20 to 90℃, and the mineral powder is a mineral rich in Ca, Mg, Fe and other ions which can react with carbon dioxide.

[0017] Preferably, when the measuring device measures, the temperature in the reaction pool is 20-90℃ to simulate the geological conditions, and the pressure in the reaction pool and the reference pool is not greater than 40 MPa after the carbon dioxide is introduced.

[0018] Based on the foregoing measuring device, a method for measuring the carbon sequestration rate and reaction rate of CO2-water-rock mineralization reaction, comprising the following steps:

[0019] Step 1), select the mineral to be reacted and prepare it into powder, and close all valves in the measuring device;

[0020] Step 2), according to the measurement requirements, weigh a small amount of the powder prepared in Step 1) and place it in the reaction cell, tightly cover the reaction cell and the reference cell, open the ninth valve, the first valve, the second valve, and vacuumize the reaction cell and the reference cell, close the ninth valve, the first valve, and the second valve after reaching the predetermined vacuum degree, and close the vacuum pump; then simultaneously inject pure water into the reaction cell and the reference cell, the volume of the pure water injected into the reaction cell and the reference cell is not more than 2 / 3 of the total volume, the volume of the pure water injected into the reaction cell and the reference cell is the same, the reaction cell and the reference cell are kept sealed during the water injection process, and the water injection port provided on the reaction cell and the reference cell is closed after the water injection is completed;

[0021] Step 3), open the sixth valve, the seventh valve, the eighth valve, the first valve, the second valve, the third valve, the fourth valve, and the fifth valve, and then set the heating temperature of the electric heating bin; inject carbon dioxide gas into the reaction cell and the reference cell through the carbon dioxide gas source to a predetermined pressure, so that the injected carbon dioxide gas is excessive; then close the first valve, the second valve, and the fourth valve in turn, and then close the sixth valve, the seventh valve, the eighth valve, and the carbon dioxide gas source; because the injected carbon dioxide is far excessive, with the passage of time, the carbon dioxide gas in the reaction cell reacts with the powder to cause mineralization reaction, and the pressure in the reaction cell decreases, and the differential pressure meter measures the pressure difference between the reaction cell and the reference cell; the data acquisition card collects the pressure data of the reaction cell measured by the pressure sensor and the pressure difference data measured by the differential pressure meter, and transmits them to the readout display for storage, until the readout on the differential pressure meter no longer changes, i.e. the pressure difference between the reaction cell and the reference cell no longer changes with time; the data acquisition card transmits the collected data to the readout display, and the data is processed, the readout display shows the curve I of the pressure difference changing with time in real time, and the curve II of the amount of carbon dioxide consumed in the mineralization reaction in the reaction cell changing with time in real time, and saves the curves I and II shown in real time;

[0022] Step 4), open the fourth valve, transfer the carbon dioxide in the reference cell to the reaction cell until the pressure in the reference cell and the reaction cell reaches a new equilibrium, and then open the sixth valve, the seventh valve, the eighth valve, the first valve, the second valve, the third valve, the fourth valve, and the fifth valve, inject carbon dioxide gas into the reaction cell and the reference cell through the carbon dioxide gas source to the predetermined pressure, and then close the fourth valve, the sixth valve, the seventh valve, the eighth valve, the first valve, the second valve, and the carbon dioxide gas source and the metering pump; the data acquisition card collects the pressure data of the reaction cell measured by the pressure sensor and the pressure difference data measured by the differential pressure meter within a period of time, and transmits them to the readout display, and the data is processed to obtain the leakage difference between the reaction cell and the reference cell;

[0023] Step 5), the leakage amount difference between the reaction cell obtained in step 4) and the reference cell is used to modify the curve II obtained in step 3), i.e. to correct the amount of carbon dioxide consumed by the mineralization reaction, so as to obtain a curve III of the actual consumption amount of carbon dioxide in the reaction cell for the mineralization reaction with respect to time, which eliminates the influence of leakage; and then combined with the gas state equation, the actual consumption amount of carbon dioxide participating in the mineralization reaction in the reaction cell, the actual reaction rate and the carbon fixation rate of the mineralization reaction are finally obtained;

[0024] The calculation process of the actual consumption amount of carbon dioxide participating in the mineralization reaction in the reaction cell is as follows:

[0025] n(t) = n1-n2 (1)

[0026] Wherein, P1V1 = Z1n1RT (2)

[0027] (P1-ΔP(t))V1 = Z2 n2RT (3)

[0028] According to formula (2) and (3), formula (1) is transformed into

[0029]

[0030] P1-initial pressure at the beginning of the reaction, Pa;

[0031] ΔP(t)-pressure change value at time t, Pa;

[0032] V1-volume of the space in the reaction cell except water at the beginning of the reaction, m 3 ;

[0033] n1-amount of substance of carbon dioxide at the beginning of the reaction, mol;

[0034] n2-amount of substance of carbon dioxide at time t after the beginning of the reaction, mol;

[0035] Z1-CO2 gas compression factor at the initial reaction pressure;

[0036] Z2-CO2 gas compression factor at the corresponding pressure at time t after the beginning of the reaction

[0037] R-molar gas constant, in the International System of Units, R = 8.31 J / (mol·K);

[0038] T-reaction temperature, K;

[0039] The carbon fixation rate CP is calculated according to the following formula:

[0040]

[0041] n(∞)-CO2 consumption at the completion of the reaction.

[0042] m - the mass of the powder in step 2), g.

[0043] The calculation process of the actual reaction rate of the carbon dioxide participating in the mineralization reaction in the reaction cell is as follows:

[0044] The pressure change value ΔP(t) of the mineralization reaction in the reaction cell obtained in step 5) is substituted into formula (4), and then the derivative of formula (4) with respect to t is obtained, and the actual reaction rate of the carbon dioxide is:

[0045]

[0046] Preferably, in step 2), the predetermined vacuum degree is 100-1000 Pa.

[0047] Preferably, in step 3), the predetermined pressure is 0.1-40 MPa.

[0048] Compared with the prior art, the present application has the following beneficial effects and advantages:

[0049] 1. A reaction kettle with the same capacity as the reaction cell is used as a reference cell, and the pressure difference between the two containers is measured by using a differential pressure gauge, thereby eliminating the influence of the carbon dioxide dissolved in water, and making the measurement result more reliable;

[0050] 2. The same reference cell as the reaction cell is used, and the pressure difference between the two containers is measured by using a differential pressure gauge, thereby accurately measuring the small pressure change under high pressure, and obtaining accurate carbon dioxide consumption data;

[0051] 3. The carbon sequestration rate and the reaction rate during the mineralization reaction can be monitored online, and the carbon dioxide mineralization rate can be monitored in real time;

[0052] 4. The difference between the leakage amounts of the two reaction cells after the reaction is measured by using a differential pressure method, and the carbon dioxide consumption is corrected. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 FIG. 1 is a schematic diagram of a CO2-water-rock mineralization reaction carbon sequestration rate and reaction rate measuring device according to the present application;

[0054] Figure 2 FIG. 2 is a graph of the pressure change value of the mineralization reaction in the reaction cell in Example 2 changing with time;

[0055] Figure 3 FIG. 3 is a graph of the actual reaction rate of the mineralization reaction in the reaction cell in Example 2 changing with time;

[0056] In the figure: first valve 1, second valve 2, third valve 3, fourth valve 4, fifth valve 5, pressure sensor 6, reaction cell 7, mineral powder 8, electric heating bin 9, differential pressure gauge 10, filter I 11, filter II 12, reference cell 13, carbon dioxide gas source bottle 14, sixth valve 15, gas buffer cylinder 16, seventh valve 17, vacuum pump 18, ninth valve 19, eighth valve 20, metering pump 21, data acquisition card 22, readout display 23. DETAILED DESCRIPTION

[0057] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying 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. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0058] Embodiment 1

[0059] A device for measuring the carbon sequestration rate and reaction rate of CO2-water-rock mineralization reaction, the measuring device comprising a carbon dioxide gas source 14, a sixth valve 15, a gas buffer cylinder 16, a seventh valve 17, a metering pump 21, an eighth valve 20, an electric heating bin 9, and a data acquisition card 22 for data acquisition, a readout display 23 for data processing and display; the electric heating bin 9 is provided with a placement table, a reaction cell 7, a reference cell 13, a third valve 3, a filter I 11, a differential pressure gauge 10, a filter II 12, a fifth valve 5, and a fourth valve 4. The carbon dioxide gas source 14, the sixth valve 15, the gas buffer cylinder 16, the seventh valve 17, the metering pump 21, and the eighth valve 20 are connected in sequence by a gas conveying pipeline, and the gas conveying pipeline downstream of the eighth valve 20 is divided into three parallel gas conveying branches: pipeline I, pipeline II, and pipeline V. The first valve 1 is arranged on the pipeline I, the second valve 2 is arranged on the pipeline II, and the pipeline V is connected with the vacuum pump 18 and provided with the ninth valve 19. After the carbon dioxide gas is output from the carbon dioxide gas source 14, it passes through the sixth valve 15, the gas buffer cylinder 16, the seventh valve 17, the metering pump 21, and the eighth valve 20 in sequence, and then enters the reaction cell 7 and the reference cell 13 in the electric heating bin 9 through the parallel first valve 1 and second valve 2. The carbon dioxide gas flowing through the first valve 1 enters the reaction cell 7 through the pipeline I, and the carbon dioxide gas flowing through the second valve 2 enters the reference cell 13 through the pipeline II. The vacuum pump 18 draws vacuum in the reference cell 7 and the reaction cell 13 in the electric heating bin 9 through a pipeline, so that the reaction cell 7 and the reference cell 13 are in a vacuum state before use, and then the vacuum pump 18 and the ninth valve 19 are closed. The carbon dioxide gas source 14 inputs carbon dioxide into the reaction cell 7 and the reference cell 13 through the gas conveying pipeline.

[0060] The two same reaction kettles are placed on the platform, wherein the reaction kettle provided with the pressure sensor 6 is the reaction pool 7, and the other reaction kettle is the reference pool 13. The reaction pool 7 is filled with pure water and mineral powder 8, and the reference pool 13 is filled with pure water. The pipeline I and the pipeline II are communicated through the pipeline III, so that the reaction pool 7 and the reference pool 13 are also communicated through the pipeline III. The third valve 3, the filter I 11, the differential pressure gauge 10, the filter II 12 and the fifth valve 5 are arranged on the pipeline III. From the connection between the pipeline III and the pipeline I, the third valve 3, the filter I 11, the differential pressure gauge 10, the filter II 12 and the fifth valve 5 are sequentially arranged to the connection between the pipeline III and the pipeline II. The pipeline IV is arranged in parallel with the differential pressure gauge 10. One end of the pipeline IV is connected with the pipeline between the third valve 3 and the filter I 11, and the other end of the pipeline IV is connected with the pipeline between the filter II 12 and the fifth valve 5. The fourth valve 4 is arranged on the pipeline IV. Thus, when the fourth valve 4 is closed and the third valve 3 and the fifth valve 5 are opened, the carbon dioxide gas flowing through the first valve 1 flows into the reaction pool 7 and the third valve 3 respectively. The carbon dioxide gas flowing through the third valve 3 flows through the filter I 11 and then reaches the differential pressure gauge 10. The carbon dioxide gas flowing through the second valve 2 flows into the reference pool 13 and the fifth valve 5 respectively. The carbon dioxide gas flowing through the fifth valve 5 flows through the filter II 12 and then reaches the differential pressure gauge 10. At this time, the differential pressure gauge 10 measures the pressure difference of the carbon dioxide at both ends. When the fourth valve 4, the third valve 3 and the fifth valve 5 are opened together, the carbon dioxide gas flowing through the third valve 3 is directly communicated with the carbon dioxide gas flowing through the fifth valve 5 through the pipeline IV. At this time, the pressure difference of the carbon dioxide at both ends of the differential pressure gauge 10 is 0 because the differential pressure gauge 10 is connected in parallel.

[0061] The reaction pool 7 is further provided with an exhaust valve and a liquid level gauge. The exhaust valve prevents the reaction kettle from exploding due to excessive pressure. The liquid level gauge displays the water level of the pure water in the reaction pool 7.

[0062] The data acquisition card 22 is used to collect the readings of the pressure sensor 6 and the differential pressure gauge 10, the flow reading of the metering pump 21, and transmit the collected readings to the reading display 23.

[0063] The heating temperature range of the electric heating bin 9 is 20-90℃. The mineral powder 8 is a mineral rich in Ca, Mg, Fe and other ions which can react with carbon dioxide.

[0064] When the measuring device is measuring, the temperature in the reaction pool 7 is 70℃ to simulate the geological conditions. ， The carbon dioxide is introduced to make the pressure in the reaction pool 7 and the reference pool 13 not greater than 40MPa.

[0065] Example 2

[0066] Based on the foregoing measuring device, a method for measuring the carbon sequestration rate and reaction rate of CO2-water-rock mineralization reaction, comprising the following steps:

[0067] Step 1), select basalt and prepare it into powder, and close all valves in the measuring device;

[0068] The volume of the reaction tank 7 and the reference tank 13 in this embodiment is 1L.

[0069] Step 2), according to the measurement requirements, 10g of the powder prepared in step 1) is placed in the reaction tank, the reaction tank and the reference tank are tightly covered, the ninth valve 20, the first valve 1 and the second valve 2 are opened, the reaction tank 7 and the reference tank 13 are vacuumized, and after reaching 100Pa, the ninth valve, the first valve and the second valve are closed, and the vacuum pump 18 is closed. Then, 2 / 3 of the volume of pure water is injected into the reaction tank 7 and the reference tank 13 at the same time, the volume of pure water injected into the reaction tank and the reference tank is the same, and the injection process is kept sealed. After the injection is completed, the water inlet on the reaction tank and the reference tank is closed:

[0070] Step 3), the sixth valve 15, the seventh valve 17, the eighth valve 19, the first valve 1, the second valve 2, the third valve 3, the fourth valve 4 and the fifth valve 5 are opened, and then the heating temperature of the electric heating bin 9 is set to 70℃. Through the carbon dioxide gas source 14, carbon dioxide gas is injected into the reaction tank and the reference tank at the same time until the pressure reaches 3MPa. According to the amount of carbon dioxide required for complete mineralization of the powder in the reaction tank, the amount of injected carbon dioxide is far more than the amount of carbon dioxide required for the carbon dioxide mineralization reaction. Then, the first valve, the second valve and the fourth valve are closed in turn, and then the sixth valve, the seventh valve, the eighth valve and the carbon dioxide gas source are closed. Because the injected carbon dioxide is far more than the required amount, with the passage of time, the carbon dioxide gas in the reaction tank 7 reacts with the powder to cause the pressure in the reaction tank 7 to drop, and the pressure difference between the reaction tank and the reference tank is measured by the differential pressure gauge 10. The pressure data of the reaction tank 7 measured by the pressure sensor 6 and the pressure difference data measured by the differential pressure gauge 10 are collected by the data acquisition card 22 and transmitted to the readout display 23 for storage. When the readout on the differential pressure gauge 10 no longer changes, i.e. the pressure difference between the reaction tank 7 and the reference tank 13 no longer changes with time, the collected data is transmitted to the readout display 23 by the data acquisition card 22, and the data is processed to show the curve I of the pressure change value changing with time and the curve II of the amount of carbon dioxide consumed in the mineralization reaction in the reaction tank 7 changing with time in real time, and the curves I and II are saved in real time.

[0071] Step 4), open the fourth valve 4, carbon dioxide in the reference cell 13 is transported to the reaction cell 7, the pressure of the reference cell 13 and the reaction cell 7 reaches equilibrium again, and the sixth valve 15, the seventh valve 17, the eighth valve 19, the first valve 1, the second valve 2, the third valve 3, the fourth valve 4, the fifth valve 5 are opened, carbon dioxide gas is injected into the reaction cell and the reference cell through the carbon dioxide gas source 14 to 3 MPa, and then the fourth valve 4, the sixth valve 15, the seventh valve 17, the eighth valve 19, the first valve 1, the second valve 2, the carbon dioxide gas source 14 and the metering pump 21 are closed; the data acquisition card 22 collects the pressure data of the reaction cell 7 measured by the pressure sensor 6 and the pressure difference data measured by the differential pressure gauge 10 within 8 hours, and transmits them to the readout display 22, and the data is processed to obtain the leakage difference between the reaction cell 7 and the reference cell 13;

[0072] After the above 8 hours, the pressure in the reaction cell 7 is measured to be 2.96 MPa, and the pressure difference measured by the differential pressure gauge 10 is 0.001 KPa;

[0073] Step 5), the leakage difference between the reaction cell and the reference cell obtained in step 4) is used to correct the curve II obtained in step 3), that is, the amount of carbon dioxide consumed in the mineralization reaction is corrected, and the actual consumption of carbon dioxide in the mineralization reaction in the reaction cell 7 is obtained. The curve III changes with time; combined with the gas state equation, the actual consumption of carbon dioxide participating in the mineralization reaction in the reaction cell 7, the actual reaction rate and the carbon fixation rate of the mineralization reaction are finally obtained;

[0074] The calculation process of the actual consumption of carbon dioxide participating in the mineralization reaction is as follows:

[0075] n(t)=n1-n2 (1)

[0076] Wherein, P1V1=Z1n1RT (2)

[0077] (P1-ΔP(t))V1=Z2 n2RT (3)

[0078] According to formula (2) and (3), formula (1) is transformed into

[0079]

[0080] P1-Initial pressure at the beginning of the reaction, Pa;

[0081] ΔP(t)-Pressure change value at time t, Pa;

[0082] V1-Volume of the reaction cell excluding water, m 3 ;

[0083] n1-Amount of substance of carbon dioxide at the beginning of the reaction, mol;

[0084] n2 - amount of carbon dioxide substance at t time after reaction starts, mol;

[0085] Z1 - CO2 gas compressibility factor at initial pressure of reaction;

[0086] Z2 - CO2 gas compressibility factor at corresponding pressure at t time after reaction starts;

[0087] R - molar gas constant, R = 8.31 J / (mol·K) in International System of Units;

[0088] T - reaction temperature, K;

[0089] Carbon fixation rate CP is calculated according to the following formula:

[0090]

[0091] n(∞) - actual consumption of CO2 at completion of reaction.

[0092] m - mass of powder weighed in step 2), g.

[0093] The calculation process of the actual reaction rate of carbon dioxide participating in the mineralization reaction is as follows:

[0094] The pressure change value ΔP(t) of the mineralization reaction at t time in the reaction cell 7 obtained by eliminating the influence of leakage in step 5) is substituted into formula (4), and then the derivative of formula (4) with respect to t is obtained to obtain the actual reaction rate of carbon dioxide:

[0095]

[0096] The experimental data obtained are shown in Table 1, and the actual consumption of carbon dioxide calculated therefrom is 4.5×10 - 2 mol, the carbon fixation rate is 19.9%, and the actual reaction rate is shown in Table 2. Figure 2 Figure 3

[0097] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent replacement or change according to the technical solution and inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.​​

Claims

1. A device for measuring the carbon fixation rate and reaction rate of CO2-water-mineralization reaction, comprising a CO2 gas source, a sixth valve, a gas buffer cylinder, a seventh valve, a metering pump, an eighth valve, an electric heating bin, and a data acquisition card for data acquisition, a readout display for data processing and display; the electric heating bin is provided with a placement table, a reaction cell, a reference cell, a third valve, a filter I, a differential pressure gauge, a filter II, a fifth valve, and a fourth valve; the CO2 gas source, the sixth valve, the gas buffer cylinder, the seventh valve, the metering pump, and the eighth valve are connected in sequence by a gas pipeline; the gas pipeline downstream of the eighth valve is divided into three parallel gas pipelines: pipeline I, pipeline II, and pipeline V; the first valve is arranged on the pipeline I, and the second valve is arranged on the pipeline II; the pipeline V is connected with a vacuum pump, and the ninth valve is arranged on the pipeline V; after the CO2 gas is output from the CO2 gas source, the CO2 gas sequentially passes through the sixth valve, the gas buffer cylinder, the seventh valve, the metering pump, and the eighth valve, and then enters the reaction cell and the reference cell in the electric heating bin through the parallel first valve and second valve; the CO2 gas flowing through the first valve enters the reaction cell through the pipeline I, and the CO2 gas flowing through the second valve enters the reference cell through the pipeline II; the vacuum pump is used to vacuumize the reference cell and the reaction cell in the electric heating bin through a pipeline, so that the reaction cell and the reference cell are in a vacuum state before use; then, the vacuum pump and the ninth valve are closed, and the CO2 gas source inputs CO2 into the reaction cell and the reference cell through the gas pipeline; Two identical reaction kettles are placed on the shelf, wherein, the reaction cell provided with a pressure sensor is the reaction cell, and the reaction cell is internally provided with pure water and a small amount of mineral powder; the other reaction cell is the reference cell, and the reference cell is internally provided with pure water; the pipeline I and the pipeline II are connected by a pipeline III, so that the reaction cell and the reference cell are also connected by the pipeline III; the third valve, the filter I, the differential pressure gauge, the filter II, and the fifth valve are arranged on the pipeline III; from the connection between the pipeline III and the pipeline I, the third valve, the filter I, the differential pressure gauge, the filter II, and the fifth valve are sequentially arranged to the connection between the pipeline III and the pipeline II; in addition, the pipeline IV is arranged in parallel with the differential pressure gauge; one end of the pipeline IV is connected with the pipeline between the third valve and the filter I, and the other end of the pipeline IV is connected with the pipeline between the filter II and the fifth valve; the fourth valve is arranged on the pipeline IV; thus, when the fourth valve is closed and the third valve and the fifth valve are opened, the CO2 gas flowing through the first valve 1 flows into the reaction cell and flows through the third valve; the CO2 gas flowing through the third valve then flows through the filter I and reaches the differential pressure gauge; in addition, the CO2 gas flowing through the second valve flows into the reference cell and flows through the fifth valve; the CO2 gas flowing through the fifth valve then flows through the filter II and reaches the differential pressure gauge; at this time, the differential pressure gauge measures the pressure difference of the CO2 at both ends; when the fourth valve, the third valve, and the fifth valve are opened together, the CO2 gas flowing through the third valve is directly connected with the CO2 gas flowing through the fifth valve through the pipeline IV; at this time, the pressure difference of the CO2 at both ends of the differential pressure gauge is 0 due to the parallel connection. The reaction tank is further provided with an exhaust valve and a liquid level meter.

2. The measuring device of claim 1, wherein, The volume of the reaction tank and the reference tank is 1-50 L.

3. The measuring device of claim 1, wherein, The data acquisition card is used for collecting the readings of the pressure sensor and the differential pressure gauge, the flow reading of the metering pump, and transmitting the collected readings to the reading display.

4. The measuring device of claim 1, wherein, The heating temperature of the electric heating bin ranges from 20 to 90 DEG C; and the mineral powder is a mineral rich in Ca, Mg and Fe ions for mineralization reaction with carbon dioxide.

5. The measuring device of claim 1, wherein, In order to simulate geological conditions, the temperature in the reaction tank is 20-90 DEG C, and the pressure in the reaction tank and the reference tank is not greater than 40 MPa after the carbon dioxide is introduced.

6. A method for measuring the carbon sequestration rate and reaction rate of CO2-water-rock mineralization reaction based on the measuring device of any one of claims 1-5, comprising the following steps: Step 1), selecting a mineral to be reacted and preparing it into powder, and closing all valves in the measuring device; Step 2), placing a small amount of the powder prepared in step 1) in the reaction tank according to the measurement requirement, tightly closing the reaction tank and the reference tank, opening the ninth valve, the first valve and the second valve, vacuumizing the reaction tank and the reference tank, closing the ninth valve, the first valve and the second valve after reaching the predetermined vacuum degree, and closing the vacuum pump; then simultaneously injecting water into the reaction tank and the reference tank, the volume of the water being not more than 2 / 3 of the total volume of the reaction tank and the reference tank, the volume of the water injected into the reaction tank being the same as that injected into the reference tank, keeping the reaction tank and the reference tank sealed during the water injection process, and closing the water injection port provided on the reaction tank and the reference tank after the water injection is completed; Step 3), opening the sixth valve, the seventh valve, the eighth valve, the first valve, the second valve, the third valve, the fourth valve and the fifth valve, then setting the heating temperature of the electric heating bin; simultaneously injecting carbon dioxide gas into the reaction tank and the reference tank through the carbon dioxide gas source until reaching the predetermined pressure, so that the injected carbon dioxide gas is excessive; then closing the first valve, the second valve and the fourth valve in sequence, and then closing the sixth valve, the seventh valve, the eighth valve and the carbon dioxide gas source; because the introduced carbon dioxide is far excessive, with the lapse of time, the carbon dioxide gas in the reaction tank reacts with the powder to cause the pressure in the reaction tank to decrease, and the differential pressure gauge measures the pressure difference between the reaction tank and the reference tank; the data acquisition card collects the pressure data of the reaction tank measured by the pressure sensor and the pressure difference data measured by the differential pressure gauge, and transmits them to the reading display for storage, until the reading on the differential pressure gauge no longer changes, i.e. the pressure difference between the reaction tank and the reference tank no longer changes with time; the data acquisition card transmits the collected data to the reading display, the data are processed, the reading display shows the curve I of the pressure difference changing with time and the curve II of the amount of carbon dioxide consumed in the mineralization reaction in the reaction tank changing with time in real time, and the curves I and II shown in real time are stored. Step 4), open the fourth valve, carbon dioxide in the reference cell is transported to the reaction cell, the pressure of the reference cell and the reaction cell reaches a new equilibrium, and the sixth valve, the seventh valve, the eighth valve, the first valve, the second valve, the third valve, the fourth valve and the fifth valve are opened, carbon dioxide gas is injected into the reaction cell and the reference cell through the carbon dioxide gas source to the predetermined pressure, and then the fourth valve, the sixth valve, the seventh valve, the eighth valve, the first valve, the second valve and the carbon dioxide gas source and the metering pump are closed; the data acquisition card collects the pressure data of the reaction cell measured by the pressure sensor and the pressure difference data measured by the differential pressure gauge within a period of time, and transmits the data to the readout display, and the data is processed to obtain the leakage difference between the reaction cell and the reference cell; Step 5), the leakage difference between the reaction cell and the reference cell obtained in step 4) is used to correct the curve II obtained in step 3), that is, the amount of carbon dioxide consumed by the mineralization reaction is corrected, and a curve III of the actual consumption of carbon dioxide in the reaction cell for the mineralization reaction with time is obtained; combined with the gas state equation, the actual consumption of carbon dioxide participating in the mineralization reaction in the reaction cell, the actual reaction rate and the carbon fixation rate of the mineralization reaction are finally obtained; The calculation process of the actual consumption of carbon dioxide participating in the mineralization reaction in the reaction cell is as follows: n(t)=n1-n2 (1) Wherein, P1V1=Z1n1RT (2) (P1-ΔP(t))V1=Z2 n2RT (3) According to formula (2) and (3), formula (1) is transformed into P1-initial pressure at the beginning of the reaction, Pa; ΔP(t)-pressure change value at time t, Pa; V1 - Volume of the space in the reaction cell, other than water, at the start of the reaction, m 3 ; n1-substance amount of carbon dioxide at the beginning of the reaction, mol; n2-substance amount of carbon dioxide at time t after the reaction starts, mol; Z1-CO2 gas compression factor at the initial pressure at the beginning of the reaction; Z2-CO2 gas compression factor at the corresponding pressure after the reaction starts at time t; R-molar gas constant, R=8.31 J / (mol·K) in the International System of Units; T-reaction temperature, K; The carbon fixation rate of the mineralization reaction in the reaction cell is calculated by the following formula: CP-carbon fixation rate; n(∞)-actual consumption of CO2 at the completion of the reaction; m-mass of the powder in step 2), g; The calculation process of the actual reaction rate of carbon dioxide participating in the mineralization reaction in the reaction cell is as follows: Substitute the pressure change value ΔP(t) of the mineralization reaction in the reaction cell obtained in step 5) into formula (4), and then derive formula (4) with respect to t to obtain the actual reaction rate of carbon dioxide:

7. The method of measuring according to claim 6, wherein, In step 2), the predetermined vacuum degree is 100-1000 Pa.

8. The measurement method according to claim 6, characterized by, In step 3), the predetermined pressure is 0.1-40 MPa.

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