Ultrasonic-assisted CO2 trapping device for magnesium ore pulp

Abstract

The invention provides an ultrasonic-assisted device for capturing CO2 from magnesium ore pulp, which belongs to the technical field of gas collection and comprises a main pipeline, and a carbon dioxide gas tank, a gas flow controller, a three-way valve, an adsorber, an ultrasonic generator and a gas analyzer are sequentially arranged on the main pipeline; the magnesium ore powder is used as a raw material, the raw material source is rich, the preparation process is simple, and the cost is low; an ultrasonic technology is introduced, liquid drops are broken through ultrasonic waves, the specific surface area of ore pulp is increased, the property of the ore pulp is changed, and the carbon dioxide trapping capacity is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of gas collection and relates to an ultrasonic-assisted magnesium ore slurry CO2 capture device. Background Art

[0002] Carbon dioxide capture, utilization and storage (CCUS) technology refers to the technology of separating CO2 from relevant emission sources, capturing, compressing and transporting it to a specific location for utilization or injecting it into a reservoir for storage to achieve long-term separation of captured CO2 from the atmosphere. This technology is considered to be the most promising carbon emission reduction technology. CO2 capture technology is also a key link in CCUS technology. At present, CO2 capture processes can be divided into the following three categories: pre-combustion capture, oxygen-enriched combustion capture (combustion capture) and post-combustion capture. Most CO2 capture uses post-combustion capture technology.

[0003] The mainstream technologies for capturing CO2 after fossil fuel combustion include chemical absorption, physical absorption, adsorption separation and membrane separation. Among them, chemical absorption has a fast absorption speed, large absorption capacity, good market prospects and is the most widely used. The principle of chemical absorption is that the solvent reacts chemically with CO2 at low temperature to absorb it, and when heated, the saturated absorbent undergoes the reverse reaction of absorption, thereby desorbing CO2.

[0004] In recent years, there have been many reports on the use of alkali metals and alkaline oxides as CO2 adsorbents, among which adsorbents based on MgO and CaO are the research hotspots, including MgO / Al2O3, mesoporous MgO, MgO-TiO2, MgO-SiO2, MgO-C, MgO-ZrO2, etc.

[0005] At present, MgO-based adsorbents are usually obtained from magnesium ore powder, which is abundant and low-cost. The preparation process is simple, which not only reduces costs but also reduces energy consumption. However, the CO2 capture performance needs to be further improved. Summary of the invention

[0006] In order to solve the technical problems existing in the above-mentioned background technology, the present embodiment configures magnesium ore powder into slurry, and uses ultrasonic assistance to break up the droplets, increase the specific surface area of ​​the slurry, change the properties of the slurry, and improve the ability to capture carbon dioxide.

[0007] In order to realize the above technical scheme, the present invention provides an ultrasonic-assisted magnesium ore slurry CO2 capture device, comprising: a main line, on which a carbon dioxide gas tank, a gas flow controller, a three-way valve, an adsorber, an ultrasonic generator and a gas analyzer are sequentially arranged; one end of the gas analyzer is connected to a nitrogen tank, and the other end is connected to the three-way valve, and the gas analyzer is purged with nitrogen for a set time before the experiment; the gas flow controller is used to control the carbon dioxide gas flow rate to simulate the field environment; the three-way valve is used to pass 10% CO2 into the absorber containing a magnesium ore slurry adsorbent with a certain solid-liquid ratio, and the gas analyzer is used for testing; the ultrasonic generator is used to control the temperature and ultrasonic power.

[0008] Furthermore, the CO2 analyzer was first purged with N2 for 15 minutes; CO2 with a standard volume fraction of 10% was used at a flow rate of 100 mL / min to simulate the CO2 in industrial flue gas; when the flow rate was stable, 10% CO2 was passed into the absorber containing a magnesium slurry adsorbent with a certain solid-liquid ratio by controlling the three-way valve, and the gas analyzer started testing; the temperature and ultrasonic power were controlled by an ultrasonic generator, and the gas flow rate was controlled by a gas flow controller.

[0009] Furthermore, the magnesium slurry adsorbent is prepared by preparing magnesium ore powder into slurry, and using ultrasonic wave to assist in breaking up droplets, thereby increasing the specific surface area of ​​the slurry, changing the properties of the slurry, and improving the ability to capture carbon dioxide.

[0010] Furthermore, the slurry preparation method is as follows: the magnesium ore powder is calcined at 550° C. for 4 hours in a muffle furnace; a set amount of ore powder is added with a corresponding mass of water according to a corresponding solid-liquid ratio, and mixed evenly to obtain the slurry required for the experiment.

[0011] Furthermore, the solid-liquid ratio of mineral powder to water is 1:10.

[0012] The beneficial effects of the present invention are:

[0013] The present invention provides an ultrasonic-assisted magnesium ore slurry CO2 capture device, comprising: a main pipeline, on which a carbon dioxide gas tank, a gas flow controller, a three-way valve, an adsorber, an ultrasonic generator and a gas analyzer are sequentially arranged, belonging to a greenhouse gas CO2 capture technology, using magnesium ore powder as raw material, with abundant raw material sources, a simple preparation process and low cost. Ultrasonic technology is introduced to break droplets by ultrasonic waves, increase the specific surface area of ​​the slurry, change the properties of the slurry, and improve the carbon dioxide capture capacity. A new technology with low cost, green and pollution-free, good CO2 capture performance and regeneration performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0015] Figure 1 It is a diagram of the experimental device of the present invention;

[0016] Figure 2 It is the adsorption curve diagram of CO2 under different solid-liquid ratios of the present invention;

[0017] Figure 3 It is the adsorption curve diagram of CO2 at different temperatures of the present invention;

[0018] Figure 4 It is the adsorption curve diagram of the present invention under different CO2 flow rates;

[0019] Figure 5 It is the adsorption curve diagram of CO2 under different ultrasonic powers of the present invention;

[0020] Figure 6 A diagram showing the carbon dioxide adsorption capacity of the regeneration experiment of the present invention;

[0021] Among them: 1. Nitrogen tank; 2. Carbon dioxide gas tank; 3. Pressure reducing valve; 4. Gas mass flow meter; 5. Three-way valve A; 6. Ultrasonic generator; 7. Three-way valve B; 8. Absorber; 9. Gas analyzer; 10. Data recorder. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0023] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in this embodiment have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0024] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0025] In the present invention, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention, and do not specifically refer to any part or element in the present invention and should not be understood as limitations on the present invention.

[0026] In the present invention, terms such as "fixed connection", "connected", "connection", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. Relevant scientific research or technical personnel in this field can determine the specific meanings of the above terms in the present invention according to specific circumstances, and they should not be understood as limiting the present invention.

[0027] Embodiment 1, as Figure 1-Figure 5 As shown, this embodiment provides an ultrasonic-assisted magnesium ore slurry CO2 capture device, including: a flow display, an ultrasonic generator, a gas flow controller, a nitrogen tank, a carbon dioxide gas tank, a three-way valve, a hand-held composite gas analyzer, a one-way valve and an absorber. The carbon dioxide gas tank, the gas flow controller, the three-way valve, the absorber, the ultrasonic generator and the gas analyzer are sequentially arranged on the main line. One end of the gas analyzer is connected to the nitrogen tank, and the other end is connected to the three-way valve. Before the experiment, the gas analyzer is purged with nitrogen for a set time; the gas flow controller is used to control the carbon dioxide gas flow rate to simulate the field environment; the three-way valve is used to pass 10% CO2 into the absorber containing a magnesium ore slurry adsorbent with a certain solid-liquid ratio, and the gas analyzer is tested; the ultrasonic generator is used to control the temperature and ultrasonic power.

[0028] The experimental process is as follows Figure 1 As shown. In the adsorption-related experiments of the present invention, the CO2 analyzer is first purged with N2 for about 15 minutes. CO2 with a standard volume fraction of 10% is used at a flow rate of 100 mL / min to simulate CO2 in industrial flue gas. When the flow rate is stable, 10% CO2 is passed into the absorber containing a magnesium ore slurry adsorbent with a certain solid-liquid ratio by controlling the three-way valve, and the analyzer starts testing. The temperature and ultrasonic power are controlled by an ultrasonic generator, and the gas flow rate is controlled by a gas flow controller.

[0029] Table 2-1 Experimental related materials

[0030]

[0031] Table 2-2 Experimental instruments and equipment

[0032]

[0033] In this embodiment, magnesium ore powder is configured into slurry, and ultrasonic waves are used to assist in breaking up droplets, thereby increasing the specific surface area of ​​the slurry, changing the properties of the slurry, and improving the ability to capture carbon dioxide.

[0034] Ultrasonic technology is introduced into the magnesium ore slurry flue gas CO2 capture system to improve the CO2 capture and regeneration performance, and develop a new CO2 capture technology with low cost, abundant raw materials, green and pollution-free, and good capture and regeneration performance.

[0035] Magnesium ore powder can be used to prepare MgO-based CO2 capture materials by simple calcination. The material preparation is simple and low-cost. It is prepared into slurry and ultrasonic assistance is introduced to increase the specific surface area of ​​the slurry and improve the CO2 capture capacity.

[0036] Preparation method: Magnesium ore powder is calcined in a muffle furnace at 550℃ for 4h. A certain amount of ore powder is added to the corresponding mass of water according to the corresponding solid-liquid ratio and mixed evenly to obtain the slurry required for the experiment.

[0037] Adsorption process: The experimental process is as follows Figure 1 As shown. In the adsorption-related experiments of this embodiment, the CO2 analyzer is first purged with N2 for about 15 minutes. A standard volume fraction of 10% CO2 is used at a flow rate of 100 mL / min to simulate CO2 in industrial flue gas. When the flow rate is stable, 10% CO2 is passed into the absorber containing a magnesium ore slurry adsorbent with a certain solid-liquid ratio by controlling the three-way valve, and the analyzer starts testing. The temperature and ultrasonic power are controlled by an ultrasonic generator, and the gas flow rate is controlled by a gas mass flowmeter.

[0038] Variable investigation: Investigate the best choice of the following variables in turn, and conduct experiments using the optimal conditions.

[0039] ①Solid-liquid ratio: 1:10, 2:10, 3:10;

[0040] ②Temperature: 20℃, 40℃, 60℃, 80℃;

[0041] ③ Gas speed: 100ml / min, 150ml / min, 200ml / min;

[0042] ④Ultrasonic power: 40W, 80W, 120W;

[0043] Regeneration experiment: The saturated absorbent was filtered and dried, and the solid was calcined at 550°C for 3 hours. The CO2 adsorption test was repeated 8 times.

[0044] Characterization of adsorbents: (1) Fourier transform infrared spectroscopy (FT-IR). The infrared spectrum is determined by measuring the interference pattern and performing Fourier transformation on the interference pattern. This experiment used a Nicolet 5DXC (Nicolet Instrument Corp, America) infrared spectrometer. This 2000-800cm -1 is the scanning range, and its resolution is 2cm -1 During the sample preparation process, KBr was used for tableting.

[0045] (2) Specific surface area and pore structure analysis (BET). In this experiment, the BET pore size and distribution and specific surface area were measured using a Tristar 3020 physical adsorption instrument from Micromeritics. The pore size and distribution were measured using the Barrett-Joyner-Halenda (BJH) adsorption isotherm method. The specific surface area was calculated using the Brunauer-Emmett-Teller (BET) model.

[0046] Selection of solid-liquid ratio of magnesium ore slurry. In this experimental study, the calcination of magnesium ore powder is the first step to explore the solid-liquid ratio of slurry. The best solid-liquid ratio is first selected from the three conditions of ore powder and water solid-liquid ratio of 1:10, 2:10, and 3:10.

[0047] In each experiment, 5g of calcined magnesium ore powder was used to prepare the slurry for the test, and the gas flow rate was set to 100ml / min, the ultrasonic power was set to 120W, and the adsorption temperature was set to 60℃.

[0048] Figure 2 It is the adsorption curve at different solid-liquid ratios, showing the adsorption capacity values ​​at different doping ratios.

[0049] Combining the experimental data and the charts, it can be seen that the time for adsorption to reach equilibrium is about 60min to 75min. When the solid-liquid ratio is 1:10, the time for adsorption to reach equilibrium is the longest and the adsorption capacity is the largest. By calculation, the carbon dioxide adsorption capacity under the conditions of solid-liquid ratio of 1:10, 2:10, and 3:10 is 1.28mmol / g, 1.00mmol / g, and 1.17mmol / g, respectively.

[0050] In summary, the main component of the mineral powder is MgO, which is not easily soluble in water, with a solubility of 0.00062g / 100ml (0℃) and 0.0086g / 100ml (30℃) in water. The lower the solid-liquid ratio when preparing the slurry, the more conducive it is to the dissolution of MgO and the adsorption of CO2. Therefore, a solid-liquid ratio of 1:10 should be selected to investigate the adsorption temperature in the next step.

[0051] The adsorption temperature was determined under the following experimental conditions: 5 g magnesium ore powder, solid-liquid ratio of 1:10, gas flow rate of 100 ml / min, ultrasonic power of 120 W. The adsorption temperatures were 20°C, 40°C, 60°C and 80°C.

[0052] Figure 3 The adsorption curves at different temperatures show the corresponding adsorption capacities. The adsorption capacities at different temperatures are 1.27mmol / g, 1.67mmol / g, 1.28mmol / g, and 2.58mmol / g. The adsorption capacity reaches the maximum at 80℃. Therefore, 80℃ is selected as the best.

[0053] The ultimate purpose of the experiment is to use it in industrial practice. This section of the experiment examines the effect of gas flow on adsorption. The gas flow rates examined are 100ml / min, 150ml / min, and 200ml / min. The experimental conditions are 5g magnesium ore powder, solid-liquid ratio of 1:10, adsorption temperature of 80℃, and ultrasonic power of 120W.

[0054] Figure 4 The effect of different gas flow rates on adsorption is shown, showing the adsorption capacity of magnesium ore slurry at different flow rates. When the flow rate is 150ml / min, the adsorption capacity is 2.58mmol / g. The adsorption capacities of the two flow rates of 100ml / min and 200ml / min are 2.77mmol / g and 1.51mmol / g respectively. It can be seen from the figure that as the flow rate increases, the time required to reach adsorption equilibrium is shorter, but under the premise of ensuring a higher adsorption capacity, combined with industrial practice, industrial flue gas is treated as quickly and as much as possible, so a gas flow rate of 150ml / min is selected for subsequent experiments.

[0055] The influence of ultrasonic power on adsorption effect. Ultrasonic waves can cause breakage of droplets. When elastic vibrations in the ultrasonic band propagate in liquid, different effects are produced as the elastic vibration intensity (sound intensity) increases. When strong ultrasonic waves propagate in liquid, they can arouse strong sound wave vibrations, produce cavitation, and cause the entire medium to explode and turn into droplets. The magnesium slurry after ultrasound has a huge specific surface area and has a high absorption efficiency for carbon dioxide; ultrasonic strengthening can also change the properties of magnesium slurry and improve the absorption performance of magnesium slurry for carbon dioxide from all aspects.

[0056] This experiment tests the effect of ultrasonic power on the carbon dioxide adsorption performance of magnesium ore slurry. The experimental conditions are: 5g magnesium ore powder, solid-liquid ratio of 1:10, adsorption temperature of 80℃, gas flow rate of 150ml / min. The ultrasonic power is 40W, 80W, and 120W respectively.

[0057] Figure 5 The effect of different ultrasonic powers on the adsorption effect. Figure 5 It can be found that at 120W, the adsorption effect of carbon dioxide is the best, which is 2.77mmol / g. It can be preliminarily judged that the higher the ultrasonic power, the stronger the sound wave vibration, the larger the specific surface area of ​​the magnesium slurry, and the better the adsorption effect.

[0058] In order to save natural resources and realize a circular green economy, this section investigates the recycling performance of adsorption, combining industrial practice.

[0059] The regeneration performance was investigated by taking the product obtained under the optimal conditions (solid-liquid ratio of 1:10, adsorption temperature of 80°C, gas flow rate of 150ml / min, ultrasonic power of 120W), that is, the adsorbent saturated with adsorption was filtered and dried to obtain a solid, which was calcined at 550°C for 3h. The calcined solid was then subjected to the CO2 adsorption experiment again under the optimal conditions, filtered, dried, and calcined, and repeated 9 times.

[0060] like Figure 6 The adsorption capacity of the 9-cycle regeneration process is basically decreasing. The magnesium ore powder will be lost each time it is regenerated.

[0061] The adsorption capacity in the eighth cycle is still greater than 1mmol / g. Combined with the previous experiments, it can be seen that magnesium slurry as an adsorbent under the assistance of ultrasound has excellent recycling performance, and the adsorption performance decreases little with the increase of the number of cycles.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An ultrasonic-assisted magnesium ore slurry CO2 capture device, characterized in that: include: The main pipeline is equipped with a carbon dioxide gas tank, a gas flow controller, a three-way valve, an adsorber, an ultrasonic generator and a gas analyzer in sequence; one end of the gas analyzer is connected to the nitrogen tank, and the other end is connected to the three-way valve. Before the experiment, the gas analyzer is purged with nitrogen for a set time; the gas flow controller is used to control the flow rate of carbon dioxide gas to simulate the field environment; the three-way valve is used to pass 10% CO2 into the absorber containing a magnesium ore slurry adsorbent with a certain solid-liquid ratio, and the gas analyzer is tested; the ultrasonic generator is used to control the temperature and ultrasonic power.

2. The ultrasonic-assisted magnesium ore slurry CO2 capture device according to claim 1, characterized in that: First, the CO2 analyzer was purged with N2 for 15 minutes; a standard volume fraction of 10% CO2 was used at a flow rate of 100 mL / min to simulate the CO2 in industrial flue gas; when the flow rate was stable, 10% CO2 was passed into the absorber containing a magnesium slurry adsorbent with a certain solid-liquid ratio by controlling the three-way valve, and the gas analyzer began to test; the temperature and ultrasonic power were controlled by an ultrasonic generator, and the gas flow rate was controlled by a gas flow controller.

3. The ultrasonic-assisted magnesium ore slurry CO2 capture device according to claim 1, characterized in that: Magnesium slurry adsorbent is made by preparing magnesium ore powder into slurry and using ultrasonic assistance to break up the droplets, increase the specific surface area of ​​the slurry, change the properties of the slurry, and improve the ability to capture carbon dioxide.

4. The ultrasonic-assisted magnesium ore slurry CO2 capture device according to claim 3, characterized in that: Slurry preparation method: magnesium ore powder is calcined at 550°C in a muffle furnace for 4 hours; a set amount of ore powder is added to a corresponding mass of water according to a corresponding solid-liquid ratio, and mixed evenly to obtain the slurry required for the experiment.

5. The ultrasonic-assisted magnesium ore slurry CO2 capture device according to claim 4, characterized in that: The solid-liquid ratio of mineral powder and water is 1:10.

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