Device and method for measuring carbon sequestration rate and reaction rate of CO2-water-rock mineralization reaction

Abstract

The invention belongs to the technical field of carbon sequestration, and particularly relates to a device and a method for measuring the carbon sequestration rate and the reaction rate of a 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 and a reading display for data processing and displaying, wherein the electric heating bin comprises a reaction tank, a reference tank and a differential pressure gauge; according to the measuring method based on the measuring device, the differential pressure gauge is used for measuring the pressure difference between the two reaction tanks and the reference tank, tiny pressure changes under high pressure can be accurately measured, CO2 real-time consumption data are obtained, the measuring accuracy is improved, and the measuring result is more reliable; the amount of needed mineral powder is small, the pressure in the reaction tank is high, the pressure difference before and after the reaction is very small, and a conventional pressure sensor can bring a large error when measuring the pressure change; the carbon sequestration rate and the CO2 reaction rate in the mineralization reaction process are monitored on line, and the carbon dioxide mineralization rate can be monitored in real time.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon sequestration, and in particular relates to a device and method for measuring the carbon fixation rate and reaction rate of a CO2-water-rock mineralization reaction. Background Art

[0002] The principle of CO2 mineralization is to react CO2 with alkaline minerals to generate carbonate minerals. This reaction requires certain temperature and pressure conditions, usually above 200°C and above 10MPa. The products of the mineralization reaction are mainly calcium carbonate, magnesium carbonate and other minerals, which are stable and chemically inert and can store CO2 for a long time. The essence of CO2 mineralization is to simulate the chemical weathering process of natural rocks in nature, and use minerals containing calcium and magnesium elements to mineralize CO2 into stable solid carbonates, thereby achieving CO2 emission reduction.

[0003] The advantages of CO2 mineralization are manifold. First, CO2 mineralization is a new type of CO2 emission reduction technology that can convert CO2 into stable minerals, thereby achieving long-term storage and utilization. Second, it can reduce CO2 emissions, reduce greenhouse gas concentrations, and mitigate the impact of climate change. In addition, CO2 mineralization can also provide a new way for the development and utilization of mineral resources and promote economic development. In the future, CO2 mineralization technology will be more widely used and promoted to create a better future for mankind.

[0004] At present, the research on carbon dioxide mineralization reaction is mainly focused on analyzing the amount of mineralization products generated after the mineralization reaction, estimating the amount of carbon fixation and carbon dioxide storage. However, the above measurement method has certain defects and cannot accurately calculate the amount of carbon dioxide consumed by the mineralization reaction, which is mainly manifested in:

[0005] First, carbon dioxide is soluble in water, and the carbon dioxide consumption calculated using traditional methods does not exclude the influence of the carbon dioxide dissolved in water, which affects the accuracy of the calculation results;

[0006] Second, for the measurement of CO2 mineralization consumption, the existing volumetric method is based on the typical chemical reaction equation, without considering the actual reaction process and the degree of reaction. The accuracy of its CO2 mineralization estimation is questionable. In short, considering the complexity of the real reaction and the non-steady-state characteristics of the 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 large error when the pressure change is small, thus affecting the accuracy of the measurement result;

[0008] Fourth, the traditional method is unable to monitor the carbon fixation rate and reaction rate during the mineralization reaction online. At the same time, it also has shortcomings such as cumbersome measurement steps, inconvenient operation, and large experimental workload. Summary of the invention

[0009] In order to overcome the deficiencies in the prior art, the purpose of the present invention is to provide a device and method for measuring the carbon fixation rate and reaction rate of the CO2-water-rock mineralization reaction. 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 the accuracy of the data, simplifies the steps of the measurement method, and effectively reduces the workload.

[0010] To achieve the above object, the present invention adopts the following technical solutions:

[0011] A device for measuring the carbon fixation rate and reaction rate of a CO2-water-rock mineralization reaction, the 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 chamber, a data acquisition card for data acquisition, and a reading display for data processing and display; the electric heating chamber is provided with a storage 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, and the gas pipeline downstream of the eighth valve is divided into three parallel gas transmission branches: pipeline I, pipeline II, and pipeline V, a first valve is provided on pipeline I, a second valve is provided on pipeline II, pipeline V is connected to a vacuum pump, and a ninth valve is provided on pipeline V. 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 passes through the first valve and the second valve in parallel to enter the reaction cell and the reference cell in the electric heating chamber. The carbon dioxide gas flowing through the first valve enters the reaction cell through pipeline I, and the carbon dioxide gas flowing through the second valve enters the reference cell through pipeline II; the vacuum pump evacuates the reference cell and the reaction cell in the electric heating chamber through the pipeline, so that the reaction cell and the reference cell are in a vacuum state before use, and then the vacuum pump and the ninth valve are closed, and the carbon dioxide gas source inputs carbon dioxide into the reaction cell and the reference cell through the gas pipeline.

[0012] Two identical reactors are placed on the storage table, wherein the reactor with a pressure sensor is a reaction pool, which is built with pure water and a small amount of mineral powder, and the other reactor is a reference pool, which is built with pure water. Pipeline I and pipeline II are connected through pipeline III, so that the reaction pool and the reference pool are also connected through pipeline III; pipeline III is provided with a third valve, filter I, differential pressure gauge, filter II, and a fifth valve, starting from the connection between pipeline III and pipeline I, passing through the third valve, filter I, differential pressure gauge filter II, and the fifth valve in sequence to the connection between pipeline III and pipeline II, and a pipeline IV is provided in parallel with the differential pressure gauge, one end of pipeline IV is connected to the pipeline between the third valve and filter I, and the other end is connected to the pipeline between filter II and the fifth valve, and a fourth valve is provided on 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, and the carbon dioxide gas flowing through the third valve then flows through the filter I to the differential pressure gauge, and the carbon dioxide gas flowing through the second valve flows into the reference pool and the fifth valve respectively, and the carbon dioxide gas flowing through the fifth valve then flows through the filter II to the differential pressure gauge. At this time, the differential pressure gauge 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 connected to 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 gauge is 0 because it is connected in parallel.

[0013] The reaction tank is also equipped with an exhaust valve and a liquid level gauge. The exhaust valve prevents the reactor from exploding due to excessive pressure, and the water level gauge displays the pure water level inside the reaction tank.

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

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

[0016] Preferably, the heating temperature range of the electric heating chamber is 20-90° C.; the mineral powder is a mineral rich in Ca, Mg, Fe and other ions that undergoes a mineralization reaction with carbon dioxide.

[0017] Preferably, when the measuring device is measuring, in order to simulate geological conditions, the temperature in the reaction pool is 20-90°C, and carbon dioxide is introduced so that the pressure in the reaction pool and the reference pool is no more than 40MPa.

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

[0019] Step 1), selecting the mineral to be reacted and preparing it into powder, and closing 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, cover the reaction cell and the reference cell, open the ninth valve, the first valve, and the second valve, evacuate the reaction cell and the reference cell, and close the ninth valve, the first valve, and the second valve after reaching a predetermined vacuum degree, and turn off the vacuum pump; then simultaneously inject pure water not exceeding 2 / 3 of the total volume into the reaction cell and the reference cell, the volume of pure water injected into the reaction cell and the reference cell is the same, keep the reaction cell and the reference cell sealed during the water injection process, and close the water injection port set on the reaction cell and the reference cell 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 chamber; inject carbon dioxide gas into the reaction pool and the reference pool at the same time 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, 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 carbon dioxide introduced is far in excess, over time, the carbon dioxide gas in the reaction pool reacts with the powder to form a mineralization reaction in the reaction pool The pressure drops, and the differential pressure gauge measures the pressure difference between the reaction pool and the reference pool; the data acquisition card collects the pressure data of the reaction pool 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, that is, the pressure difference between the reaction pool and the reference pool no longer changes with time; the data acquisition card transmits the collected data to the reading display, and the data is processed, and the reading display shows in real time a curve I showing the pressure difference changing with time, and a curve II showing in real time the amount of carbon dioxide consumed by the mineralization reaction in the reaction pool changing with time, and the curves I and II shown in real time are stored;

[0022] Step 4), open the fourth valve, the carbon dioxide in the reference pool is transmitted to the reaction pool, until the pressure of the reference pool and the reaction pool reaches a balance again, and 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 inject carbon dioxide gas into the reaction pool and the reference pool at the same time 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, the carbon dioxide gas source and the metering pump; the data acquisition card collects the pressure data of the reaction pool measured by the pressure sensor and the pressure difference data measured by the differential pressure gauge within a period of time, and transmits them to the reading display, and the data is processed to obtain the leakage difference between the reaction pool and the reference pool;

[0023] Step 5), using the leakage difference between the reaction pool and the reference pool obtained in step 4) to correct the curve II obtained in step 3), that is, to correct the amount of carbon dioxide consumed by the mineralization reaction, and obtain a curve III showing the actual consumption of carbon dioxide in the mineralization reaction in the reaction pool with the effect of leakage eliminated over time; and then combining the gas state equation, finally obtaining the actual consumption of carbon dioxide participating in the mineralization reaction in the reaction pool, the actual reaction rate and the carbon fixation rate of the mineralization reaction;

[0024] The calculation process of the actual consumption of carbon dioxide involved in the mineralization reaction in the reaction tank is:

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

[0026] Where P1V1=Z1n1RT (2)

[0027] (P1-ΔP(t))V1=Z2n2RT (3)

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

[0029]

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

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

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

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

[0034] n2-the amount of carbon dioxide at time t after the reaction starts, 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 reaction starts

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

[0038] T-reaction temperature, K;

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

[0040]

[0041] n(∞)-CO2 consumption when the reaction is complete.

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

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

[0044] Substitute the pressure change value ΔP(t) at time t of the mineralization reaction in the reaction pool to eliminate the leakage effect obtained in step 5) into formula (4), and then take the derivative of formula (4) with respect to t to obtain the actual reaction rate of carbon dioxide:

[0045]

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

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

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

[0049] 1. A reactor with the same volume as the reaction tank is used as the reference tank, and the pressure difference between the two containers is measured using a differential pressure gauge, eliminating the influence of the carbon dioxide dissolved in water, 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 a differential pressure gauge, which can accurately measure small pressure changes under higher pressure and obtain accurate carbon dioxide consumption data;

[0051] 3. It can realize online monitoring of carbon fixation rate and reaction rate during the mineralization reaction, and can monitor the mineralization rate of carbon dioxide in real time;

[0052] 4. Use the differential pressure method to measure the difference in leakage between the two reaction cells after the reaction is completed, and correct the carbon dioxide consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a schematic diagram of a device for measuring the carbon fixation rate and reaction rate of the CO2-water-rock mineralization reaction of the present invention;

[0054] Figure 2 The relationship diagram of the pressure change value during the mineralization reaction in the reaction tank in Example 2 versus time;

[0055] Figure 3 This is a graph showing the relationship between the actual reaction rate and time during the mineralization reaction in the reaction tank in Example 2;

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

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] Example 1

[0059] A device for measuring carbon fixation rate and reaction rate of CO2-water-rock mineralization reaction, the device comprises 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 chamber 9, a data acquisition card 22 for data acquisition, and a reading display 23 for data processing and display; the electric heating chamber 9 is provided with a storage 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 through a gas transmission pipeline, and the gas transmission pipeline downstream of the eighth valve 20 is divided into three parallel gas transmission branches: pipeline I, pipeline II, and pipeline V, a first valve 1 is provided on pipeline I, a second valve 2 is provided on pipeline II, pipeline V is connected to a vacuum pump 18, and a ninth valve 19 is provided on pipeline V. 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 passes through the first valve 1 and the second valve 2 connected in parallel to enter the reaction cell 7 and the reference cell 13 in the electric heating chamber 9. 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 evacuates the reference cell 7 and the reaction cell 13 in the electric heating chamber 9 through the 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, and the carbon dioxide gas source 14 inputs carbon dioxide into the reaction cell 7 and the reference cell 13 through the gas pipeline.

[0060] Two identical reactors are placed on the storage table, wherein the reactor with the pressure sensor 6 is a reaction pool 7, which is filled with pure water and mineral powder 8, and the other reactor is a reference pool 13, which is filled with pure water. Pipeline I and pipeline II are connected through pipeline III, so that the reaction pool 7 and the reference pool 13 are also connected through pipeline III; pipeline III is provided with a third valve 3, a filter I 11, a differential pressure gauge 10, a filter II 12, and a fifth valve 5, starting from the connection between pipeline III and pipeline I, passing through the third valve 3, filter I 11, differential pressure gauge 10, filter II 12, and the fifth valve 5 in sequence to the connection between pipeline III and pipeline II, and a pipeline IV is provided in parallel with the differential pressure gauge 10, one end of pipeline IV is connected to the pipeline between the third valve 3 and filter I 11, and the other end is connected to the pipeline between the filter II 12 and the fifth valve 5, and a fourth valve 4 is provided on 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, and the carbon dioxide gas flowing through the third valve 3 then flows through the filter Ⅰ 11 to the differential pressure gauge 10, and the carbon dioxide gas flowing through the second valve 2 flows into the reference pool 13 and the fifth valve 5 respectively, and the carbon dioxide gas flowing through the fifth valve 5 then flows through the filter Ⅱ 12 to 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 connected to 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 it is connected in parallel.

[0061] The reaction tank 7 is also provided with an exhaust valve and a liquid level gauge. The exhaust valve prevents the reaction kettle from exploding due to excessive pressure, and the water level gauge displays the pure water level built into the reaction tank 7.

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

[0063] The heating temperature of the electric heating chamber 9 is in the range of 20 to 90° C. The mineral powder 8 is a mineral rich in Ca, Mg, Fe and other ions that undergoes a mineralization reaction with carbon dioxide.

[0064] When the measuring device is measuring, in order to simulate the geological conditions, the temperature in the reaction pool 7 is 70°C. ， The carbon dioxide is introduced so that the pressure inside the reaction cell 7 and the reference cell 13 is not greater than 40 MPa.

[0065] Example 2

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

[0067] Step 1), selecting basalt and preparing it into powder, and closing all valves in the measuring device;

[0068] In this embodiment, the volume of the reaction cell 7 and the reference cell 13 is 1L.

[0069] Step 2), according to the measurement requirements, 10g of the powder prepared in step 1) is placed in the reaction cell, and after the reaction cell and the reference cell are tightly covered, the ninth valve 20, the first valve 1, and the second valve 2 are opened to evacuate the reaction cell 7 and the reference cell 13. After reaching 100Pa, the ninth valve, the first valve, the second valve, and the vacuum pump 18 are closed; then, 2 / 3 of the volume of the reaction cell and the reference cell is injected into the reaction cell 7 and the reference cell 13 simultaneously. 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. After the water injection is completed, the water injection port set on the reaction cell and the reference cell is closed:

[0070] Step 3), open 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, and then set the heating temperature of the electric heating chamber 9 to 70°C; inject carbon dioxide gas to 3MPa into the reaction cell and the reference cell through the carbon dioxide gas source 14; according to the amount of carbon dioxide required for complete mineralization of the powder in the reaction cell, the amount of carbon dioxide injected is far in excess of the amount of carbon dioxide required for the carbon dioxide mineralization reaction; then close the first valve, the second valve, the fourth valve, and then close the sixth valve, the seventh valve, the eighth valve and the carbon dioxide gas source in turn; because the carbon dioxide introduced is far in excess, over time, the carbon dioxide in the reaction cell 7 The carbon dioxide gas and the powder undergo a mineralization reaction until the pressure in the reaction pool 7 drops, and the differential pressure gauge 10 measures the pressure difference between the reaction pool and the reference pool; the data acquisition card 22 collects the pressure data of the reaction pool 7 measured by the pressure sensor 6 and the pressure difference data measured by the differential pressure gauge 10, and transmits them to the reading display 23 for storage; when the reading on the differential pressure gauge 10 no longer changes, that is, the pressure difference between the reaction pool 7 and the reference pool 13 no longer changes with time; the data acquisition card 22 transmits the collected data to the reading display 23, and the data is processed, and the reading display 23 shows in real time a curve I showing the pressure change value over time, and a curve II showing in real time the amount of carbon dioxide consumed by the mineralization reaction in the reaction pool 7 over time, and the curves I and II shown in real time are stored;

[0071] Step 4), open the fourth valve 4, the carbon dioxide in the reference pool 13 is transmitted to the reaction pool 7, until the pressure of the reference pool 13 and the reaction pool 7 is balanced again, and open 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, and inject carbon dioxide gas to 3MPa into the reaction pool and the reference pool through the carbon dioxide gas source 14, and then close 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; the data acquisition card 22 collects the pressure data of the reaction pool 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 reading display 22, and the data is processed to obtain the leakage difference between the reaction pool 7 and the reference pool 13;

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

[0073] Step 5), using the leakage difference between the reaction pool and the reference pool obtained in step 4) to correct the curve II obtained in step 3), that is, to correct the amount of carbon dioxide consumed by the mineralization reaction, and obtain the curve III of the actual consumption of carbon dioxide in the mineralization reaction in the reaction pool 7 with the leakage effect eliminated over time; and then combining the gas state equation, finally obtain the actual consumption of carbon dioxide participating in the mineralization reaction in the reaction pool 7, the actual reaction rate and the carbon fixation rate of the mineralization reaction;

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

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

[0076] Where P1V1=Z1n1RT (2)

[0077] (P1-ΔP(t))V1=Z2n2RT (3)

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

[0079]

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

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

[0082] V1-the volume of the reaction tank excluding water, m 3 ;

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

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

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

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

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

[0088] T-reaction temperature, K;

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

[0090]

[0091] n(∞)-actual CO2 consumption when the reaction is completed.

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

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

[0094] Substituting the pressure change value ΔP(t) of the mineralization reaction at time t in the reaction tank 7 obtained in step 5) to eliminate the leakage effect into formula (4), and then taking the derivative of formula (4) with respect to t, the actual reaction rate of carbon dioxide can be obtained:

[0095]

[0096] The experimental data are as follows Figure 2 As shown in the figure, the actual carbon dioxide consumption calculated is 4.5×10 - 2 mol, the carbon fixation rate is 19.9%, and the actual reaction rate is Figure 3 shown.

[0097] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A device for measuring the carbon fixation rate and reaction rate of a CO2-water-rock mineralization reaction, the 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 chamber, and a data acquisition card for data acquisition, and a reading display for data processing and display; a storage 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 are arranged in the electric heating chamber; a carbon dioxide gas source, a sixth valve, a gas buffer cylinder, a seventh valve, a metering pump, and an eighth valve are connected in sequence through a gas pipeline, and the gas pipeline downstream of the eighth valve is divided into three parallel gas transmission branches: pipeline I, pipeline II, and pipeline V, pipeline I is provided with a first valve, pipeline II is provided with a second valve, and pipeline V is provided with a third valve. A second valve is provided on the pipe V, the pipe V is connected to the vacuum pump, and a ninth valve is provided on the pipe V; 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, the eighth valve in sequence, and then passes through the first valve and the second valve connected in parallel to enter the reaction cell and the reference cell in the electric heating chamber, the carbon dioxide gas flowing through the first valve enters the reaction cell through the pipe I, and the carbon dioxide gas flowing through the second valve enters the reference cell through the pipe II; the vacuum pump evacuates the reference cell and the reaction cell in the electric heating chamber through the pipe, so that the reaction cell and the reference cell are in a vacuum state before use, and then the vacuum pump and the ninth valve are closed, and the carbon dioxide gas source inputs carbon dioxide into the reaction cell and the reference cell through the gas pipeline; Two identical reaction kettles are placed on the storage table, wherein: The reactor with a pressure sensor is a reaction pool, which is built with pure water and a small amount of mineral powder. The other reactor is a reference pool, which is built with pure water. Pipeline I and pipeline II are connected through pipeline III, so that the reaction pool and the reference pool are also connected through pipeline III. Pipeline III is provided with a third valve, filter I, differential pressure gauge, filter II, and a fifth valve. Starting from the connection between pipeline III and pipeline I, it passes through the third valve, filter I, differential pressure gauge filter II, and the fifth valve in sequence to the connection between pipeline III and pipeline II. In addition, a pipeline IV is provided in parallel with the differential pressure gauge, one end of pipeline IV is connected to the pipeline between the third valve and filter I, and the other end is connected to the pipeline between filter II and the fifth valve. Pipeline IV is provided with a fourth valve. Therefore, when the first When the four valves are 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 flows through the third valve respectively, and the carbon dioxide gas flowing through the third valve then flows through the filter I to the differential pressure gauge, and the carbon dioxide gas flowing through the second valve flows into the reference pool and flows through the fifth valve respectively, and the carbon dioxide gas flowing through the fifth valve then flows through the filter II to the differential pressure gauge. At this time, the differential pressure gauge 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 connected to 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 gauge is 0 because it is connected in parallel; The reaction tank is also equipped with an exhaust valve and a liquid level gauge. The exhaust valve prevents the reactor from exploding due to excessive pressure, and the water level gauge displays the pure water level inside the reaction tank.

2. The measuring device according to claim 1, characterized in that The volumes of the reaction cell and the reference cell are 1-50L.

3. The measuring device according to claim 1, characterized in that The data acquisition card is used to collect the readings of the pressure sensor and the differential pressure gauge, the flow readings measured by the metering pump, and transmit the collected readings to the reading display.

4. The measuring device according to claim 1, characterized in that The heating temperature range of the electric heating chamber is 20-90° C.; the mineral powder is a mineral rich in Ca, Mg, Fe and other ions that undergoes a mineralization reaction with carbon dioxide.

5. The measuring device according to claim 1, characterized in that When the measuring device is measuring, in order to simulate geological conditions, the temperature in the reaction pool is 20-90° C., and carbon dioxide is introduced so that the pressure in the reaction pool and the reference pool is no more than 40 MPa.

6. A method for measuring the carbon fixation rate and reaction rate of a CO2-water-rock mineralization reaction based on the measuring device according to any one of claims 1 to 5, comprising the following steps: Step 1), selecting the mineral to be reacted and preparing it into powder, and closing all valves in the measuring device; 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, cover the reaction cell and the reference cell, open the ninth valve, the first valve, and the second valve, evacuate the reaction cell and the reference cell, close the ninth valve, the first valve, and the second valve after reaching a predetermined vacuum degree, and turn off the vacuum pump; then simultaneously inject water not exceeding 2 / 3 of the total volume of the reaction cell and the reference cell into the reaction cell and the reference cell, the volume of pure water injected into the reaction cell and the reference cell is the same, keep the reaction cell and the reference cell sealed during the water injection process, and close the water injection port set on the reaction cell and the reference cell after the water injection is completed: 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 chamber; inject carbon dioxide gas into the reaction pool and the reference pool at the same time 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, 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 carbon dioxide introduced is far in excess, over time, the carbon dioxide gas in the reaction pool reacts with the powder to form a mineralization reaction in the reaction pool The pressure drops, and the differential pressure gauge measures the pressure difference between the reaction pool and the reference pool; the data acquisition card collects the pressure data of the reaction pool 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, that is, the pressure difference between the reaction pool and the reference pool no longer changes with time; the data acquisition card transmits the collected data to the reading display, and the data is processed, and the reading display shows in real time a curve I showing the pressure difference changing with time, and a curve II showing in real time the amount of carbon dioxide consumed by the mineralization reaction in the reaction pool changing with time, and the curves I and II shown in real time are stored; Step 4), open the fourth valve, the carbon dioxide in the reference pool is transmitted to the reaction pool, until the pressure of the reference pool and the reaction pool reaches a balance again, and 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 inject carbon dioxide gas into the reaction pool and the reference pool at the same time 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, the carbon dioxide gas source and the metering pump; the data acquisition card collects the pressure data of the reaction pool measured by the pressure sensor and the pressure difference data measured by the differential pressure gauge within a period of time, and transmits them to the reading display, and the data is processed to obtain the leakage difference between the reaction pool and the reference pool; Step 5), using the leakage difference between the reaction pool and the reference pool obtained in step 4) to correct the curve II obtained in step 3), that is, to correct the amount of carbon dioxide consumed by the mineralization reaction, and obtain the curve III of the actual consumption of carbon dioxide in the mineralization reaction in the reaction pool with the leakage effect eliminated over time; and then combining the gas state equation, finally obtain the actual consumption of carbon dioxide participating in the mineralization reaction in the reaction pool, the actual reaction rate and the carbon fixation rate of the mineralization reaction; The calculation process of the actual consumption of carbon dioxide involved in the mineralization reaction in the reaction tank is: n(t)=n1-n2 (1) Where P1V1=Z1n1RT (2) (P1-ΔP(t))V1=Z2n2RT (3) According to equations (2) and (3), equation (1) is transformed into P1-initial pressure at the beginning of the reaction, Pa; ΔP(t)-pressure change at time t, Pa; V1-the volume of space in the reaction pool excluding water at the beginning of the reaction, m 3 ; n1-the amount of carbon dioxide substance at the beginning of the reaction, mol; n2-the amount of carbon dioxide at time t after the reaction starts, mol; Z1-compression factor of CO2 gas at the initial pressure at the beginning of the reaction; Z2-compression factor of CO2 gas at the corresponding pressure at time t after the reaction starts; R-molar gas constant, R=8.31J / (mol·K) in the International System of Units; T-reaction temperature, K; The carbon fixation rate of the mineralization reaction in the reaction pool is calculated by the following formula: CP-carbon fixation rate; n(∞)-actual CO2 consumption when the reaction is completed; m-the 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 tank is: Substitute the pressure change value ΔP(t) at time t of the mineralization reaction in the reaction pool to eliminate the leakage effect obtained in step 5) into formula (4), and then take the derivative of formula (4) with respect to t to obtain the actual reaction rate of carbon dioxide:

7. The measuring method according to claim 6, characterized in that: In step 2), the predetermined vacuum degree is 100-1000Pa.

8. The measuring method according to claim 6, characterized in that: In step 3), the predetermined pressure is 0.1-40 MPa.

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