Device and method for directly mineralizing carbon dioxide in air by utilizing industrial solid waste carbide slag

Abstract

The invention provides a device and method for directly mineralizing carbon dioxide in air by using industrial solid waste carbide slag, the device comprises a raw material closed-loop crushing and weighing system and a main reactor system, the raw material closed-loop crushing and weighing system is used for controlling the fineness of crushed carbide slag to be that the mass of particles with the particle size smaller than 2 mm accounts for 90%-100% of the total mass; the main reactor system comprises a bubbling bed mineralization reactor, a riser mineralization reactor and a gas-solid parallel flow downer mineralization reactor which are connected in sequence. The raw material crushing and screening system controls the granularity of the carbide slag to be-2mm, the content of the carbide slag is 90-100 wt%, then the carbide slag is fed into the main reactor system, the main reactor system works cooperatively, the bubbling bed completes pre-carbonation of alkaline substances on the surface layer and the shallow layer of the carbide slag, and the riser and downer coupling system further carbonates an intermediate product. And finally, efficient mineralization of the carbide slag is achieved, the mineralization rate is high, the conversion rate is high, the product granularity is stable, system adjustment is intelligent, CO2 emission can be effectively reduced, and resource utilization of industrial solid waste is promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide mineralization, and in particular to a device and method for directly mineralizing air carbon dioxide by using industrial solid waste carbide slag. Background Art

[0002] Carbon dioxide mineralization refers to the reaction of carbon dioxide with alkaline substances to form stable inorganic carbonate products, which is similar to the carbonate rock formation reaction occurring in the process of rock formation in nature. At present, there is a problem of slow reaction caused by low carbon dioxide concentration in the direct air mineralization (DAM) of air carbon dioxide (CO2). The carbonation reaction rate of minerals is only about 1 gCO2 / m 2 ·h (this value is generally not higher than 10), which is not conducive to increasing the fixation amount of air carbon dioxide per unit time and per unit reactor cross-sectional area.

[0003] As an industrial solid waste, carbide slag mainly comes from the process of hydrolyzing calcium carbide to produce acetylene. It is estimated that about 1.2 tons of dry carbide slag will be produced for every ton of calcium carbide produced. The main component of carbide slag is medium-strong base calcium hydroxide, and its strong alkalinity shows its unique value in mineralizing carbon dioxide in the air. By reacting with carbon dioxide, carbide slag can be converted into calcium carbonate. This process not only helps to reduce greenhouse gas emissions, but also converts industrial waste residues into valuable products, which not only reduces the environmental burden brought by industrial solid waste, but also provides an effective solution for CO2 emission reduction, promotes environmental protection and sustainable development, and realizes the high-value utilization of industrial waste. In the gas-solid carbonation reaction process of carbide slag, affected by the control of gas-solid internal and external diffusion, it is necessary to select a suitable gas-solid reaction system to take into account the processing capacity, energy consumption, reaction conversion rate and conversion rate. Summary of the Invention

[0004] The purpose of the present invention is to provide a method and device for directly mineralizing air carbon dioxide by using industrial solid waste carbide slag, constructing a data model by using key environmental parameter, material property parameters and mineralization performance parameters, so as to form a decision-making strategy to guide production, design and regulate equipment; at the same time, in the design of the reaction device, the principle of the data model is fully considered, and relevant actuators are designed and integrated according to the characteristics of the regulation strategy to smoothly complete the required production adjustment, strengthen the carbonation reaction activity of minerals in the mineralization reaction system, and then overcome the problems such as slow reaction speed caused by low carbon dioxide concentration in the direct air mineralization process.

[0005] According to an object of the present invention, the present invention provides a device for directly mineralizing air carbon dioxide by using industrial solid waste carbide slag, including a raw material closed-circuit crushing and weighing system and a main reactor system. The raw material closed-circuit crushing and weighing system is used to control the fineness of the carbide slag after crushing so that the proportion of particles with a particle size less than 2 mm in the total mass is in the range of 90% to 100%.

[0006] The main reactor system includes a bubbling bed mineralization reactor, a riser mineralization reactor, and a gas-solid co-current downer mineralization reactor connected in sequence.

[0007] The bubbling bed mineralization reactor is used for the pre-carbonation of the surface layer and shallow alkaline substances of the carbide slag. A large amount of CO2 is captured within a residence time of 10 minutes to 2 hours by means of efficient gas-solid contact, and the fine powder after the reaction is discharged as the first fine-grained calcium carbonate product. The unreacted coarse-grained intermediate product in the bubbling bed mineralization reactor is sent to the combined system of the riser mineralization reactor and the gas-solid co-current downer mineralization reactor for further carbonation reaction after being crushed or ground.

[0008] Furthermore, the raw material closed-circuit crushing and weighing system includes a crusher, a screening machine, and a raw material bin. The crusher and the screening machine form a feed particle size control system, and a weighing and metering device is provided at the bottom of the raw material bin.

[0009] Furthermore, the riser mineralization reactor realizes full contact between the carbide slag and the gas through a high gas velocity air flow of 4 - 10 m / s at the bottom, and captures the fine powder generated during the reaction as the second fine-grained calcium carbonate product.

[0010] Furthermore, the riser mineralization reactor and the gas-solid co-current downer mineralization reactor are used in combination. The gas-solid co-current downer mineralization reactor further carbonates the fine particles by means of gravity-driven gas-solid contact, and the final product is discharged from the gas-solid co-current downer mineralization reactor.

[0011] Furthermore, a gas distribution device and a baffle structure arranged axially are provided in the gas-solid co-current downer mineralization reactor for uniform air distribution, extension of the particle residence time, and breaking of particle agglomerates.

[0012] Furthermore, an auxiliary device is also included. The auxiliary device includes a blower and induced draft system, a spray humidification system, a relay humidification and air supply system with a humidification / auxiliary agent atomizing spraying function, and a product bin.

[0013] Furthermore, the main reactor system is equipped with a monitoring system. The monitoring system obtains real-time data such as CO2 inlet and outlet concentrations, temperature, relative humidity, wind speed, and solid conversion rate through on-line or off-line data collection, and monitors and adjusts the carbonation process.

[0014] According to another object of the present invention, the present invention provides a method for using the above device for directly mineralizing air carbon dioxide with industrial solid waste carbide slag, comprising the following steps:

[0015] S1. After the carbide slag raw material is weighed and recorded, it is fed into the raw material closed-circuit crushing and weighing system, and the discharge particle size is controlled to be below 2 mm. The product passing through the sieve enters the raw material bin of the reactor, and sampling and analysis are arranged in the raw material bin to determine the chemical composition and moisture content of the raw material;

[0016] S2. The carbide slag powder in the raw material bin is fed into the upper part of the bubbling bed mineralization reactor. At this time, the induced draft fan system is synchronously started, and air is fed into the bubbling bed mineralization reactor from bottom to top at an air velocity of 0.5 - 3 m / s, so that the carbide slag enters the bubbling or turbulent fluidization state; the calcium hydroxide alkaline substances on the surface layer and shallow layer of the carbide slag particles are fully carbonated in the bubbling fluidized bed, and as much CO2 as possible is captured in the external diffusion control stage in the shortest possible time; according to the component changes and properties such as particle size of the material and considering the target conversion rate of the carbide slag, under the combined action of the feeding system and the fluidization air velocity, the carbide slag stays in the bubbling bed mineralization reactor for 10 min - 2 hr and then leaves the bubbling bed; at the same time, the fine powder discharged from the bubbling bed mineralization reactor is the first fine-grained calcium carbonate product, which is collected and sent to the weighing system for weighing and total carbonate analysis;

[0017] S3. The coarse-grained calcium carbonate intermediate product that has stayed in the bubbling bed mineralization reactor for a sufficient time leaves the bubbling bed mineralization reactor and is simply crushed or ground, and then fed into a generalized fast fluidization reactor system composed of a riser mineralization reactor and a gas-solid co-current downer mineralization reactor for further carbonation reaction;

[0018] S4. In the riser mineralization reactor, the crushed solid reactants are in full contact with the high-velocity air flow of 4 - 10 m / s from the bottom of the reactor. Violent collisions, frictions, and shears occur between the gas-solid phases, between the particles, or between the particles and the inner wall of the reactor, so as to continuously and fully expose the fresh unreacted surface and promote the complete carbonation of the carbide slag; the fine powder generated in the riser mineralization reactor is collected by the filtration system and becomes the second fine-grained calcium carbonate product, which is collected and sent to the weighing system for weighing and total carbonate analysis, and the cyclone bottom product is sent to the gas-solid co-current downer reactor;

[0019] S5. A gas distribution device is arranged in the gas-solid co-current downer mineralization reactor to ensure uniform air distribution of the downward air flow. A series of baffle internal components are arranged axially to break up the particle agglomerates and extend the residence time of the fine particles in the bed. After the particles complete the reaction in the gas-solid co-current downer mineralization reactor, they can either return to the riser through the return device for continuous reaction or be discharged as the final product, weighed and the carbonate content measured.

[0020] Further, after the reaction starts, the monitoring system and the data control center start to synchronously record the inlet and outlet CO2 concentrations and gas flow rates, and start to continuously record the wind speed, temperature, relative humidity, and system pressure and atmospheric pressure data inside the reactor; simultaneously, the solid automatic sampling system starts to perform periodic sampling of the carbide slag material inside the reactor to analyze the conversion of carbide slag at different times, i.e., the carbonation situation data, such as particle size distribution, conversion rate, calcium hydroxide content, and moisture content, for the data model in the central control room to analyze and judge.

[0021] Further, during the formal operation of the device, the system data model combines the index parameter data such as the mineralization conversion rate inside the reactor with the environmental parameter data such as temperature, humidity, and moisture content mentioned above to judge the reasons for the index fluctuations; after the central control system makes a judgment on the reasons for the index changes according to the data model, it starts to issue intervention instructions to the corresponding device actuators.

[0022] The technical solution of the present invention controls the particle size of carbide slag by the raw material crushing and screening system to have a -2mm content of 90wt% to 100wt%, and then sends it into the main reactor system. The main reactor system works together, and the bubbling bed completes the pre-carbonation of the alkaline substances on the surface and in the shallow layer of the carbide slag, and the riser and downcomer coupling system further carbonates the intermediate products, ultimately realizing the efficient mineralization of carbide slag. It has the advantages of fast mineralization rate, high conversion rate, stable product particle size, intelligent system regulation, etc., can effectively reduce CO2 emissions, and promote the resource utilization of industrial solid waste. Brief Description of the Drawings

[0023] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 It is a structural schematic diagram of an embodiment of the present invention; Detailed Embodiments

[0025] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0026] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation on the present invention.

[0027] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise specifically defined. In addition, the terms "mounted", "connected" and "connected to" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] Example 1

[0029] As Figure 1 shown:

[0030] A device for directly mineralizing air carbon dioxide with industrial solid waste carbide slag includes a raw material closed-circuit crushing and weighing system and a main reactor system, wherein:

[0031] The raw material closed-circuit crushing and weighing system includes a feed particle size control system composed of a crusher and a screening machine and a raw material (undersize product) bin with a weighing and metering device. Before the carbide slag incoming material with tested components officially enters the reactor, the fineness of the carbide slag is controlled to be 90wt% - 100wt% of -2mm content through the raw material closed-circuit crushing and weighing system.

[0032] The main reactor system includes all or part of a bubbling bed mineralization reactor, a riser mineralization reactor and a gas-solid co-current downer mineralization reactor (specifically, which reactors are put into use can be flexibly combined according to production purposes or product particle size and strength characteristics), as well as a blower and induced draft system, a spray humidification system, a series of relay humidification and air supply systems with humidification / auxiliary agent atomizing spraying functions, a product bin, and a monitoring system including flow, temperature, humidity, pressure, wind speed, CO2 concentration and on-line solid sampling and its actuators.

[0033] The present invention utilizes the characteristics of a bubbling bed, such as low power consumption and a high filling ratio of solid-phase materials in the bed, to complete the carbonation of the outer layer and shallow-layer active substances of a large amount of carbide slag particles (pre-carbonation process). After partial fine particles are carbonated, they leave the reaction system in a timely manner. The unreacted intermediate products in the bubbling bed mineralization reactor are sent to the riser mineralization reactor after being crushed or without being crushed. The deep carbonation of carbide slag particles is realized by utilizing the strong gas-solid contact characteristics of the riser mineralization reactor. Finally, the riser mineralization reactor is coupled with the gas-solid co-current downcomer bed mineralization reactor, and the unreacted carbide slag carried out by particle agglomerates in the riser mineralization reactor is made to continue to react with CO2 in the fresh air in the downcomer bed in an approximate single-particle state by utilizing the gravity-following characteristics of the gas-solid co-current downcomer bed mineralization reactor. When the particles reach the specified carbonation reaction conversion rate in the downcomer bed-riser coupled reaction system, they can leave the reaction system through the bottom material seal of the downcomer bed or the riser.

[0034] The present invention simultaneously uses the classical fluidization and fast generalized fluidization systems to provide an ideal reaction site for different stages of the carbide slag carbonation reaction, completes the mineralization process of CO2 in the air at a relatively fast speed, and can realize the timely separation of qualified products. The three reactors can be selectively combined according to different requirements and material properties.

[0035] 1) The bubbling bed mineralization reactor fully carbonates the alkaline substances such as calcium hydroxide on the surface layer and shallow layer of carbide slag particles within a relatively long residence time (for example, 10 min to 2 h). By utilizing the good gas-solid contact efficiency of the fluidized bed, as much CO2 as possible is captured in the external diffusion control stage in the shortest time. The fine powder discharged from the bubbling bed is the fine-grained calcium carbonate product 1, which is sent to the weighing system for weighing and total carbonate analysis after being collected.

[0036] 2) The coarse-grained calcium carbonate intermediate product that has stayed in the bubbling bed mineralization reactor for a sufficient time leaves the bubbling bed mineralization reactor, is simply crushed or ground, and is fed into a generalized fast fluidization reactor system composed of a riser mineralization reactor and a gas-solid co-current downcomer bed mineralization reactor for further carbonation reaction.

[0037] 3) In the riser mineralization reactor, the crushed solid-phase reactants are in full contact with the high-gas-velocity (4 - 10 m / s) air flow from the bottom of the reactor (the slip velocity between gas and solid in the riser mineralization reactor is high, the axial backmixing of gas and solid is intense, and the gas-solid mass transfer is sufficient). There are intense collisions, frictions, and shears between the gas-solid phases, between particles, or between particles and the inner wall of the reactor, thereby continuously and fully exposing the fresh unreacted surface and promoting the complete carbonation of carbide slag. The fine powder generated in the riser mineralization reactor is collected by the filtration system and becomes the fine-grained calcium carbonate product 2, which is sent to the weighing system for weighing and total carbonate analysis after being collected. The cyclone bottom flow product is sent into the gas-solid co-current downcomer bed mineralization reactor.

[0038] 4) Since the gas-solid cocurrent flows against gravity and ascends in the riser mineralization reactor, there is obvious gas-solid backmixing, and it is inevitable to form some particle agglomerates, which may affect the final effect of the carbonation reaction. Therefore, in the present invention, a gas-solid cocurrent downflow bed is arranged downstream of the riser to make up for this. The particle dispersion of this gas-solid cocurrent downflow contact mode along gravity is uniform, and the particle agglomeration is much weaker than that in the bubbling bed and the riser. However, the gas-solid contact efficiency is high, and fine particles can be further carbonated in a state close to single particles to improve the CO2 mineralization effect; a gas distribution device is arranged in the downflow bed to ensure uniform air distribution of the downflow air, and a series of baffle internal components are arranged axially to break up the particle clusters and extend the residence time of the fine particles in the bed. After the particles complete the reaction in the downflow bed, they can either return to the riser mineralization reactor via the return device to continue the reaction or be discharged as the final product, weighed and measured for the carbonate content.

[0039] 5) The data center and its monitoring system of the reactor system can timely obtain historical data such as the CO2 inlet and outlet concentrations of the reaction system and the carbonate content of the solid materials in the reactor through on-line or off-line data acquisition, and make timely judgments on the current CO2 mineralization performance (mineralization situation) of the equipment, such as the gas-phase absorption rate and the conversion rate of carbide slag, according to the data; the data acquisition system will also combine and compare the historical data change trends of the temperature, relative humidity, reactor pressure and atmospheric pressure, interlayer air velocity and material moisture content of the reaction system to judge the reasons for the improvement or deterioration of the above CO2 mineralization performance indicators, so as to command the relevant actuators of the reactor to perform operation adjustment to ensure that the mineralization performance of the equipment is maintained at a high level.

[0040] 6) When the monitoring system finds that the reason for the instability of the mineralization performance indicators is that one or more of the relative humidity, material moisture content, apparent gas velocity, surface renewal frequency or the reactivity of the material itself cannot be maintained in the optimal range, corresponding adjustments can be made: turn on / off or adjust the spray system, spray humidification system and internal humidification or dehumidification of the reactor; adjust the flow rate of the induced draft fan to change the apparent gas velocity in the reactor; improve the material renewal frequency through the induced draft and blower system to strengthen the gas-solid contact; in addition, the humidification system in the bed can also add reaction aids to the bed materials.

[0041] In this embodiment, the variable control and adjustment range involved in the method for direct mineralization of CO2 from carbide slag with air are as follows: the relative humidity of air is higher than 35%, the temperature is 3 - 45°C, the material moisture content is greater than 5%, and the apparent air velocities of the bubbling bed, riser and downflow bed are 0.5 - 3 m / s, 3 - 10 m / s, and 0.5 - 8 m / s, respectively. In actual operation, the above parameters are not adjusted independently, but are organically combined according to the corresponding change trends of the parameter historical curve and the index change curve based on the process data model.

[0042] For example: when the system finds that the relative humidity in the reactor decreases from 70% to 50% and the moisture content of the material remains unchanged, the reaction conversion rate tends to slow down, and humidification intervention can be carried out by starting different spray systems, but at the same time, attention should be paid to controlling the wind speed according to the bed type;

[0043] For example: when the relative humidity in the riser is reduced from 90% to 70%, the temperature and material moisture content do not change much, but the reaction performance shows a downward trend, the system reduces the gas velocity appropriately, and at the same time increases the humidity adjustment system inside and outside the reactor and reduces the amount of return material in the down-going bed, and, if necessary, supplements are spread to enhance reactivity, so as to achieve the purpose of recovering the gas phase humidity in the riser.

[0044] In this embodiment, the evaluation of indicators such as CO2 emission reduction and mineralization rate can be verified by processing data of multiple sets of methods on the gas phase side and the solid phase side, thereby ensuring the accuracy and reliability of the reactor performance data and operation adjustment.

[0045] The solid phase balance can be calculated by measuring the change in relative carbonate content and combining the feed amount to calculate the reaction conversion rate and CO2 absorption, and combining the equipment parameters to obtain the mineralization rate; the inlet and outlet materials can also be accurately weighed, and the CO2 absorption can be inferred based on the stoichiometric relationship of the carbonation reaction. The gas phase balance directly calculates the CO2 absorption and absorption rate based on the accurately calibrated inlet and outlet gas flow history records and CO2 concentration difference history records.

[0046] The specific working mode of the present invention is as follows:

[0047] After the incoming calcium carbide slag raw materials are weighed and recorded, they are fed into a crusher (which can be a jet mill, Raymond mill, vertical mill, cone crusher, jaw crusher, roller crusher, etc.). The crusher and a screening machine (fixed screen or vibrating screen) form a closed-circuit crushing system, and the discharge particle size is mainly controlled to be below 2mm (for example, -2mm content 95wt%). The undersize product enters the raw material bin of the reactor (the raw material bin is equipped with a weight sensor to record the real-time consumption of the raw materials), and sampling and analysis are arranged in the raw material bin to determine the chemical composition and moisture content of the raw materials.

[0048] The carbide slag powder in the raw material bin is usually fed into the upper part of the bubbling bed mineralization reactor. At this time, the induced draft fan system is started synchronously to feed air into the bubbling bed from bottom to top at an air velocity of 0.5 - 3 m / s, so that the carbide slag enters the bubbling or turbulent fluidization state. The alkaline substances such as calcium hydroxide on the surface layer and shallow layer of the carbide slag particles are fully carbonated in the bubbling fluidized bed, and as much CO2 as possible is captured in the external diffusion control stage in the shortest possible time; according to the component changes and properties such as particle size of the material and considering the target conversion rate of the carbide slag, under the combined action of the feeding system and the fluidization air velocity, the carbide slag stays in the bubbling bed for 10 min - 2 h and then leaves the bubbling bed. At the same time, the fine powder discharged from the bubbling bed is the fine-grained calcium carbonate product 1, which is collected and sent to the weighing system for weighing and total carbonate analysis.

[0049] The coarse-grained calcium carbonate intermediate product that stays in the bubbling bed mineralization reactor for a sufficient time leaves the bubbling bed mineralization reactor and is simply crushed or ground, and then fed into a generalized fast fluidization reactor system composed of a riser and a gas-solid co-current downer reactor for further carbonation reaction.

[0050] In the riser mineralization reactor, the crushed solid reactants are in full contact with the high-velocity (4 - 10 m / s) air flow from the bottom of the reactor (the slip velocity between gas and solid in the riser is high, the axial backmixing of gas and solid is intense, and the gas-solid mass transfer is sufficient). There are intense collisions, frictions, and shears between the gas-solid phase, between particles, or between particles and the inner wall of the reactor, so as to continuously and fully expose the fresh unreacted surface, promoting the complete carbonation of the carbide slag; the fine powder generated in the riser mineralization reactor is collected by the filtration system and becomes the fine-grained calcium carbonate product 2, which is collected and sent to the weighing system for weighing and total carbonate analysis, and the cyclone bottom product is sent into the gas-solid co-current downer reactor.

[0051] Since the gas-solid co-current in the riser mineralization reactor moves upward against gravity, the gas-solid backmixing is obvious, and a large number of particle agglomerates are formed and wrapped around each other, which may affect the final effect of the carbonation reaction. Therefore, the present invention sets a gas-solid co-current downer downstream of the riser to make up for it. The particle dispersion of this gas-solid co-current downward contact method is uniform, and the particle agglomeration is much weaker than that of the bubbling bed and the riser. Even if particles are formed, their aggregation and dispersion frequency is extremely high. Therefore, the gas-solid contact efficiency is high, and the fine particles can be further carbonated in a state close to single particles to improve the CO2 mineralization effect. A gas distribution device is arranged in the downer to ensure uniform air distribution of the downward air. In addition, a series of baffle internal components (such as annular baffles, umbrella-shaped internal components, tower-shaped internal components, etc.) are arranged along the axis to break up the particle agglomerates and extend the residence time of the fine particles in the bed. After the particles complete the reaction in the downer, they can either return to the riser through the return device to continue the reaction or be discharged as the final product, weighed and measured for carbonate content.

[0052] After the reaction starts, the system monitoring system and the data control center begin to synchronously record the inlet and outlet CO2 concentrations and gas flow rates, and start continuously recording the wind speed, temperature, relative humidity, and system pressure and atmospheric pressure data inside the reactor. At the same time, the solid automated sampling system starts to perform periodic sampling of the carbide slag material inside the reactor to analyze the conversion (i.e., carbonation) data of the carbide slag at different times (such as particle size distribution, conversion rate, calcium hydroxide content, and moisture content) for the data model in the central control room to analyze and judge.

[0053] During the formal operation of the device, the system data model combines the index parameter data such as the mineralization conversion rate inside the reactor with the environmental parameter data such as the above-mentioned temperature, humidity, and moisture content to judge the reasons for the fluctuations of the indicators.

[0054] After the central control system makes a judgment on the reasons for the index changes based on the data model, it starts to issue intervention instructions to the corresponding device actuators. For example: after reacting for a period of time, change the induced draft and forced draft flow rates to increase the gas-solid relative velocity to improve the gas-solid mass transfer efficiency, or adjust the material circulation ratio between the downcomer bed and the riser to repeatedly strengthen the flow, mass transfer, and reaction. If it is found that the relative humidity inside a certain device drops too fast (for example, from 90% to below 60% within 1 hour), the spray humidification system of the intake pipe and the reactor is started, and if necessary, reaction aids are sprayed through the reactor humidification system during the commissioning process to enhance the reaction activity and increase the reaction rate.

[0055] When the carbide slag reaches the target conversion rate during intermittent operation, or after the system operates stably and can continuously produce qualified materials, the downcomer bed or the riser starts to gradually and continuously discharge materials to the product bin under the control of the system. At the same time, weighing and analysis are started, the CO2 capture amount is statistically calculated based on the weighing results, and compared with the statistical results of the CO2 concentration and flow rate data on the gas phase side. In addition, the CO2 capture amount can also be statistically calculated through the data of the change in the calcium hydroxide conversion rate and carbonate content of the carbide slag collected during the operation of this device. In this way, the data provided by the device of the present invention can be used for three calculation methods to measure the CO2 capture situation from different angles to ensure the reliability of the data.

[0056] The adjustment effect of the operating conditions shows the timely response of the adjustment system to the reaction indicators as shown in the following table:

[0057]

[0058] Case 1: Appropriately increasing the gas phase humidity and significantly increasing the circulation ratio of the riser / downcomer bed and the bubbling bed gas velocity can significantly increase the reaction rate and the conversion rate of carbide slag;

[0059] Case 2: When the bubbling bed gas velocity remains unchanged and the circulation ratio of the riser / downcomer bed is significantly reduced, the overall conversion rate and reaction rate are significantly reduced;

[0060] Case 3: After increasing the relative humidity of each reactor to the level of 80%-90% and increasing the circulation ratio of the riser / downcomer bed, the carbonization index is significantly improved;

[0061] Case 4: After increasing the reactor temperature and reducing the relative humidity to the level of 20%-30%, the reaction is basically stopped;

[0062] Case 5: After moderately increasing the relative humidity of the reactor, increasing the circulation ratio of the riser / downcomer bed and the gas velocity of the bubbling bed, the reaction indexes can be significantly improved (but the particle abrasion is aggravated)

[0063] In the present invention, a certain flow rate of air is directly and efficiently contacted with carbide slag processed to a suitable particle size distribution within a certain temperature and humidity range in a suitable and different gas-solid fluidized bed reactor. By periodically or non-periodically regulating the operating parameters of the reactor and the environmental physical property parameters, low-concentration carbon dioxide in the air can be effectively captured without enrichment, and finally, long-term permanent solidification or conversion into a calcium carbonate product with economic value can be achieved. By monitoring environmental variables and operating variables, the present invention can effectively capture and stably solidify low-concentration carbon dioxide in the air with low pollution and low energy consumption, and realize the resource utilization of carbide slag to obtain calcium carbonate products, which is suitable for large-scale carbon dioxide treatment and solid waste resource utilization and has good application prospects. At the same time, the reasonable design of the system equipment and its combined connection mode provided by the present invention can also improve the utilization rate of raw materials and energy, and realize the recovery and regeneration treatment of flue gas and carbide slag with low cost, low energy consumption and large scale.

[0064] Using the device and method of the present invention for treatment can make the carbonation reaction rate of carbide slag reach 10-100 gCO2 / m 2 reactor·h, which is much faster than the data reported in the existing literature (below 1 gCO2 / m 2 reactor·h), which is beneficial to significantly increasing the air CO2 fixation per unit time and reactor cross-sectional area, and consuming a large amount of carbide slag inventory as calcium carbonate materials.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An apparatus for directly mineralizing air carbon dioxide using industrial solid waste carbide slag, characterized in that, It includes a raw material closed-circuit crushing and weighing system and a main reactor system. The raw material closed-circuit crushing and weighing system is used to crush carbide slag so that the proportion of particles with a particle size less than 2 mm in the total mass is in the range of 90% to 100% after crushing. The main reactor system includes a bubbling bed mineralization reactor, a riser mineralization reactor, and a gas-solid co-current downer bed mineralization reactor connected in sequence. The bubbling bed mineralization reactor is used for the pre-carbonation of the alkaline substances on the surface layer and in the shallow layer of carbide slag. A large amount of CO2 is captured within a residence time of 10 minutes to 2 hours by means of efficient gas-solid contact, and the fine powder after the reaction is discharged as the first fine-grained calcium carbonate product. The unreacted coarse-grained intermediate product in the bubbling bed mineralization reactor is sent to the combined system of the riser mineralization reactor and the gas-solid co-current downer bed mineralization reactor for further carbonation reaction after being crushed or ground.

2. The device for directly mineralizing air carbon dioxide by using industrial solid waste carbide slag according to claim 1, wherein, The raw material closed-circuit crushing and weighing system includes a crusher, a screening machine, and a raw material bin. The crusher and the screening machine form a feed particle size control system, and a weighing and metering device is provided at the bottom of the raw material bin.

3. The device for directly mineralizing air carbon dioxide by using industrial solid waste carbide slag according to claim 1, characterized in that, The riser mineralization reactor realizes the full contact between carbide slag and gas through a high gas velocity air flow of 4 - 10 m / s at the bottom, and captures the fine powder generated during the reaction as the second fine-grained calcium carbonate product.

4. The device for directly mineralizing air carbon dioxide by using industrial solid waste carbide slag according to claim 1, characterized in that The riser mineralization reactor is used in combination with the gas-solid co-current downer bed mineralization reactor. The gas-solid co-current downer bed mineralization reactor further carbonates the fine particles by means of gravity-driven gas-solid contact, and the final product is discharged from the gas-solid co-current downer bed mineralization reactor.

5. The device for directly mineralizing air carbon dioxide by using industrial solid waste carbide slag according to claim 1, wherein A gas distribution device and a baffle structure arranged axially are provided in the gas-solid co-current downer bed mineralization reactor for uniform air distribution, extension of the particle residence time, and crushing of particle agglomerates.

6. The device for directly mineralizing air carbon dioxide by using industrial solid waste carbide slag according to claim 1, wherein, It also includes auxiliary devices. The auxiliary devices include a blower and induced draft system, a spray humidification system, a relay humidification and air supply system with a humidification / auxiliary agent atomization spraying function, and a product bin.

7. The device for directly mineralizing air carbon dioxide using industrial solid waste carbide slag according to claim 1, characterized in that, The main reactor system is equipped with a monitoring system. The monitoring system obtains real-time data of CO2 inlet and outlet concentrations, temperature, relative humidity, wind speed, and solid conversion rate through on-line or off-line data collection, and monitors and adjusts the carbonation process.

8. The method of using the device for directly mineralizing air carbon dioxide with industrial solid waste carbide slag according to claim 1, characterized in that, It includes the following steps: S1. After the carbide slag raw material is weighed and recorded, it is fed into the raw material closed-circuit crushing and weighing system. The discharge particle size is controlled to be below 2 mm, and the undersize product enters the reactor raw material bin. Sampling and analysis are arranged in the raw material bin to determine the chemical composition and moisture content of the raw material. S2. The carbide slag powder in the raw material silo is fed into the upper part of the bubbling bed mineralization reactor. At this time, the induced draft fan system is started synchronously to feed air into the bubbling bed mineralization reactor from bottom to top at an air velocity of 0.5 - 3 m / s, causing the carbide slag to enter the bubbling or turbulent fluidization state. The calcium hydroxide alkaline substances on the surface layer and shallow layer of the carbide slag particles are fully carbonated in the bubbling fluidized bed, and as much CO2 as possible is captured in the external diffusion control stage in the shortest possible time. According to the component changes and particle size properties of the materials and considering the target conversion rate of the carbide slag, under the combined action of the feeding system and the fluidization air velocity, the carbide slag stays in the bubbling bed mineralization reactor for 10 min - 2 h and then leaves the bubbling bed. At the same time, the fine powder discharged from the bubbling bed mineralization reactor is the first fine-grained calcium carbonate product. After being collected, it is sent to the weighing system for weighing and total carbonate analysis. S3. The coarse-grained calcium carbonate intermediate product that has stayed in the bubbling bed mineralization reactor for a sufficient time leaves the bubbling bed mineralization reactor and is simply crushed or ground, and then fed into a generalized fast fluidization reactor system composed of a riser mineralization reactor and a gas-solid co-current downer mineralization reactor for further carbonation reaction. S4. In the riser mineralization reactor, the crushed solid reactants are in full contact with the high-velocity air flow of 4 - 10 m / s from the bottom of the reactor. Intense collisions, frictions, and shears occur between the gas-solid phases, between particles, or between particles and the inner wall of the reactor, continuously and fully exposing fresh unreacted surfaces, promoting complete carbonation of the carbide slag. The fine powder generated in the riser mineralization reactor is collected by the filtration system and becomes the second fine-grained calcium carbonate product. After being collected, it is sent to the weighing system for weighing and total carbonate analysis, and the cyclone underflow product is sent into the gas-solid co-current downer reactor. S5. A gas distribution device is installed in the gas-solid co-current downer mineralization reactor to ensure uniform air distribution of the downward air flow. A series of baffle internal components are arranged axially to break up particle agglomerates and extend the residence time of fine particles in the bed. After the particles complete the reaction in the gas-solid co-current downer mineralization reactor, they can either return to the riser through the return device for continuous reaction or be discharged as the final product, weighed and measured for carbonate content.

9. The method according to claim 8, wherein After the reaction starts, the monitoring system and the data control center start to synchronously record the inlet and outlet CO2 concentrations and gas flow rates, and start to continuously record the air velocity, temperature, relative humidity, and system pressure and atmospheric pressure data in the reactor. At the same time, the solid automatic sampling system starts to perform periodic sampling of the carbide slag material in the reactor to analyze the conversion, i.e., carbonation situation data of the carbide slag at different times, such as particle size distribution, conversion rate, calcium hydroxide content, and moisture content, for the data model in the central control room to analyze and judge.

10. The method according to claim 8, wherein During the formal operation of the device, the system data model combines the mineralization conversion rate index parameter data in the reactor with the environmental parameter data such as temperature, humidity, and moisture content to judge the reasons for the index fluctuations. After the central control system makes a judgment on the reasons for the index changes based on the data model, it starts to issue intervention instructions to the corresponding device actuators.

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