A small mobile high-activity calcium-based desulfurizer preparation device and a preparation method thereof

Abstract

The present application relates to the field of flue gas desulfurization technology, in particular to a small mobile high-activity calcium-based desulfurizer preparation device and preparation method. The preparation method comprises the following steps: (1) industrial lime is doped with high-activity metal oxide; (2) two-stage digestion liquid is prepared; (3) the raw material is three-stage digested; (4) the product is dried and ground. Through the steps of doping the active components of industrial rotary kiln lime powder, organic solvent modification, drying and grinding, a high-activity desulfurizer with high sulfur capacity, high desulfurization efficiency and long penetration time under low-temperature sulfur-containing flue gas conditions such as steel plant heating furnace and light rail workshop is prepared. The raw material of the present application is cheap and easy to obtain, the preparation process has low energy consumption, and the present application has the advantages of low cost and good performance compared with the traditional dry desulfurizer.

Description

Technical Field

[0001] This invention relates to the field of flue gas desulfurization technology in steel plants, and in particular to a small-scale mobile high-activity calcium-based desulfurizing agent preparation device and preparation method. Background Technology

[0002] With increasingly stringent requirements for industrial flue gas emissions in my country, the sulfur dioxide gas generated in the steel industry urgently needs suitable treatment processes. Due to the low sulfur content in the low-temperature sulfur-containing flue gas from steel plant heating furnaces and light rail workshops, wet desulfurization processes are not economically viable. Dry desulfurization processes, with their advantages of low construction costs, stable operation, and low overall cost, have become the preferred choice for desulfurization in these conditions.

[0003] Dry fixed-bed desulfurization technology is mature and stable in operation, and is favored by the industry due to its small footprint and simple equipment modification. Calcium-based desulfurizers have widely available raw material sources and offer advantages over traditional sodium bicarbonate desulfurizers, including lower cost and easier byproduct treatment. Therefore, the preparation of highly active calcium-based desulfurizers has gradually become a focus of industry attention.

[0004] Quicklime is widely available and inexpensive in industry. The calcium hydroxide obtained after digestion is the main component of highly active calcium-based desulfurizers. Quicklime digestion equipment has low requirements and the digestion process is simple, so industrially, calcium hydroxide is often prepared directly through quicklime hydration digestion. The larger the specific surface area and the higher the porosity of calcium hydroxide, the stronger its activity and the better its effect in flue gas desulfurization. However, untreated industrial quicklime has poor desulfurization capacity. Therefore, maximizing the specific surface area and desulfurization activity of the product during the digestion process is the key technology. This invention innovatively uses a chlorine-containing solution instead of the traditional pure water primary digestion solution. Different stirring intensities are used to promote digestion in the three-stage digestion process, and different digestion temperatures are used to distinguish the digestion stages, ultimately producing a fluffy, highly active calcium-based desulfurizer. Furthermore, the small-scale mobile high-activity calcium-based desulfurizer preparation device can also meet the market demand for convenient, on-the-spot production of small-scale test desulfurizers, saving preparation costs and increasing flexibility. Summary of the Invention

[0005] The purpose of this invention is to address the urgent needs in the background art by providing a small-scale mobile high-activity calcium-based desulfurizer preparation device and preparation method. By optimizing digestion conditions while controlling costs, the small-scale mobile high-activity calcium-based desulfurizer preparation device can produce a highly active powdered calcium-based desulfurizer with a high specific surface area.

[0006] This invention provides a small-scale mobile high-activity calcium-based desulfurizer preparation device, comprising a first-stage digester, a second-stage digester, a third-stage digester, an atomizing nozzle, a liquid injection port, a twin-screw propeller, a heating layer, a temperature control device, a spraying device, a feed inlet, a discharge outlet, a support frame, and casters. Quicklime raw material enters the first-stage digester through the feed inlet and is fed from the beginning to the end of the digester under the stirring of the twin-screw propeller, reacting fully with the first-stage digestion liquid sprayed from the atomizing nozzle. After falling into the beginning of the second-stage digester, the material is stirred and pushed to the end of the second-stage digester by the twin-screw propeller, reacting fully with the second-stage digestion liquid sprayed from the atomizing nozzle. After falling into the beginning of the third-stage digester, the material is stirred and pushed to the very end of the third-stage digester, where the reactants are fully matured to obtain a fluffy desulfurizer powder. The ball valve at the discharge outlet is opened to collect the powder, yielding the finished industrial calcium-based desulfurizer.

[0007] Preferably, the first-stage digester, the second-stage digester, and the third-stage digester are stacked vertically and connected end to end. The stirring shafts of each layer run in opposite directions, and the stirring shafts are designed as parallel double shafts to increase the stirring intensity.

[0008] Preferably, the top of the first-stage digester and the second-stage digester are equipped with several horizontally evenly distributed atomizing nozzles. The spray range and flow rate are controlled by the spray control system. The required digesting liquid is added through the injection port, and the mass ratio of digesting liquid to raw material is 1:(0.4-1). The first-stage digesting liquid is a chlorine-containing inorganic salt solution, and the inorganic salt is one of calcium chloride, magnesium chloride, potassium chloride, and sodium chloride. The second-stage digesting liquid is an organic solvent solution, and the organic solvent is one or a mixture of diethylene glycol, 1,3-butanediol, urea, inorganic ethanol, polyethylene glycol, and ethylene glycol.

[0009] Preferably, the first-stage digester, the second-stage digester, and the third-stage digester are equipped with a dual-axis spiral propeller at the center of their chambers. The bottom arc-shaped heating layer is in close contact with the stirring range of the blades of the dual-axis spiral propeller. The digestion reaction time is controlled by the motor speed and is 15 to 30 minutes.

[0010] Preferably, the first-stage digester uses regularly shaped stirring blades, while the second-stage digester uses irregularly shaped stirring blades with different stirring intensities.

[0011] Preferably, the bottom and left and right sides of the stirring tank of the three-stage dry digester are provided with arc-shaped heating layers. The temperature control device can set the temperature of the first-stage digester, the second-stage digester and the third-stage digester in stages. The heat transfer oil in the heating layer interlayer is added through the oil injection port, and the temperature is adjustable in the range of 30 to 150°C.

[0012] Preferably, the discharge port is located below the end of the third-stage digester and is controlled by a ball valve.

[0013] Preferably, the device is controlled by casters at the bottom of four supports to control the direction of movement.

[0014] This invention provides a technical solution for preparing highly active desulfurizers using a small-scale mobile high-activity calcium-based desulfurizer preparation device, comprising the following specific steps:

[0015] S1. After industrial quicklime powder and highly active metal oxide are mixed in a specific manner, they are fed into the feed inlet of a small mobile high-activity calcium-based desulfurizing agent preparation device.

[0016] The quicklime raw materials in S2 and S1 are in full contact with the primary digestion liquid and undergo primary digestion under the weak stirring of the screw propeller. After staying for about 10-15 minutes, they are pushed into the second-stage digester. The primary digestion liquid contains a metal salt containing chlorine as an auxiliary agent.

[0017] In S3 and S2, the digestate comes into full contact with the secondary digestion liquid and undergoes secondary digestion under the strong stirring of the screw propeller. After staying for about 10-15 minutes, it is pushed into the third-stage digester. The secondary digestion liquid contains organic solvents as aids.

[0018] The digestate from S4 and S3 is vigorously stirred and matured in the third-stage digester. After staying for about 20-25 minutes, it is discharged from the outlet to obtain fluffy, highly active calcium-based desulfurizer powder.

[0019] Preferably, the quicklime mentioned in S1 is industrial powdered quicklime produced from a rotary kiln, with a calcium content greater than 90% and high activity.

[0020] Preferably, the bottom and left and right sides of the stirring tank of the three-stage dry digester in S1 are provided with arc-shaped heating layers, and the temperature can be set in stages by a temperature control device. The first and second stage digesters are equipped with atomizing nozzles, which are evenly distributed at the top of the digester, so that the digesting liquid is atomized and comes into uniform contact with the digestate in the stirring tank. The flow rate of the digesting liquid in each layer can be set separately by a spray device. Each stage digester is equipped with a twin-shaft helical propeller with stirring blades. The first stage digester uses regular blades, while the second and third stage digesters use irregular blades.

[0021] Preferably, the highly reactive metal oxide in S1 is one or more of aluminum oxide, magnesium oxide, and ferric oxide. Quicklime and the metal oxide are stirred and mixed in a primary digester. The mass ratio of the industrial powdered quicklime to the highly reactive metal oxide is 1:(0.05-0.1); more preferably, the mass ratio is 1:0.1.

[0022] Preferably, the digestive fluid used in the first-stage digester in S2 is an inorganic salt solution containing chloride ions, wherein the chloride salt content is 1-4 wt.%. More preferably, the content is 4 wt.%. The inorganic chloride salt is one of calcium chloride, magnesium chloride, potassium chloride, and sodium chloride. More preferably, the inorganic chloride salt is calcium chloride.

[0023] Preferably, the digestive fluid used in the second-stage digester in S3 is a mixture of deionized water and an organic solvent, wherein the organic solvent accounts for 1.5 to 5 wt.% of the digestive fluid. The organic solvent is one or more of diethylene glycol, 1,3-butanediol, urea, inorganic ethanol, polyethylene glycol, and ethylene glycol. A more preferred ratio is determined by the organic solvent.

[0024] Preferably, in the first and second stage digesters of S2 and S3, the mass ratio of the digesting liquid to the quicklime raw material in S1 is 1:(0.4~1), and more preferably the liquid-solid mass ratio is 1:1; the temperature of the digesting liquid is 25~60℃, and more preferably 60℃.

[0025] Preferably, the temperature inside the first and second stage digesters in S2 and S3 is 50-100°C, and more preferably 100°C.

[0026] Preferably, the temperature inside the third-stage digester in S4 is 80–120°C, and more preferably, the temperature is 100°C.

[0027] Preferably, the discharge port of the preparation device is located below the end of the third-stage digester and is controlled by a ball valve.

[0028] Compared with the prior art, the present invention has the following beneficial technical effects:

[0029] 1. The small-scale mobile high-activity calcium-based desulfurizer preparation device provided by this invention, comprising a first-stage digester, a second-stage digester, a third-stage digester, a spray head, a liquid injection port, a twin-shaft screw propeller, a heating layer, a temperature control device, a spray device, a feed inlet, a discharge outlet, a support frame, and casters, is assembled to meet the market demand for preparing small batches of calcium-based desulfurizer as test reagents. It uses industrial quicklime powder produced from a rotary kiln to prepare hydrated lime through three-stage digestion (with attached...). Figure 1 To address specific working conditions, a highly active calcium-based desulfurizing agent with high sulfur capacity, long penetration time, and high desulfurization efficiency was developed, suitable for sulfur-containing flue gas from steel plant heating furnaces and light rail workshops. The desulfurization capability of the agent was verified on a fixed-bed desulfurization experimental device. (See attached diagram) Figure 4 ).

[0030] 2. The small mobile high-activity calcium-based desulfurizer preparation device provided by the present invention can control the spraying conditions of the digesting liquid in the first-stage digester and the second-stage digester through a spraying device, and add different types of digesting liquid to meet the needs of efficient digestion of quicklime.

[0031] 3. The small mobile high-activity calcium-based desulfurizer preparation device provided by this invention allows the heating temperatures of the first-stage digester, the second-stage digester, and the third-stage digester to be individually controlled by a temperature control device, helping the reaction process within the digester to achieve the best results.

[0032] 4. The small-scale mobile high-activity calcium-based desulfurizer preparation device provided by this invention has different blade shapes for the agitators in the first-stage digestion stage compared to the second and third-stage digesters (see attached diagram). Figure 3 The first-stage digester uses full-width fan-shaped blades to achieve uniform mixing of materials and most of the digestion. The second and third-stage digesters use irregularly shaped stirring blades to make the mixing of materials more vigorous, ensuring the complete completion of the digestion reaction.

[0033] 5. The small mobile high-activity calcium-based desulfurizer preparation device provided by this invention is equipped with four casters at the bottom of the support frame, which facilitates the movement of the equipment, meets diverse placement requirements, and meets the need for convenient preparation of small batches of calcium-based desulfurizer for trial use in industrial sites.

[0034] 6. This invention uses industrial quicklime powder produced from a rotary kiln to prepare hydrated lime through three-stage slaking (see attached). Figure 1 ), based on actual working conditions, a highly active calcium-based desulfurizer with high sulfur capacity, long penetration time, and high desulfurization efficiency was developed, suitable for sulfur-containing flue gas from steel plant heating furnaces and light rail workshops; a small-scale mobile high-activity calcium-based desulfurizer preparation device (with) Figure 2 This reduces the difficulty of preparation and saves time and space costs. Furthermore, the desulfurization capacity of the obtained desulfurizing agent was verified by simulating operating conditions using a fixed-bed desulfurization experimental device (see attached). Figure 4 ).

[0035] 7. In this invention, the first-stage digester uses an inorganic solution containing chloride ions instead of traditional purified water as the digesting liquid for primary digestion, which significantly increases the solubility of calcium ions in quicklime in the solution and enhances their reaction with OH-. - The diffusion rate of the lime accelerated the digestion process.

[0036] 8. In this invention, the second-stage digester uses one or more low-cost inorganic additives to increase the surface tension of hydrated lime, enhancing its fluidity and dispersibility, thus creating favorable conditions for producing fluffy powder during the slaking stage. Simultaneously, the combination with hydrated lime increases the surface-active components, improving the specific surface area and desulfurization activity of the hydrated lime, enhancing the effective desulfurization time and maximum sulfur capacity of the desulfurizing agent under operating conditions, and effectively reducing reagent input costs.

[0037] 9. In this invention, the stirring intensity of each stage of the digester in a small-scale mobile high-activity calcium-based desulfurizer preparation device is distinguished by the shape of the stirring blades, thereby achieving precise optimization of the reaction process. The stirring blade shapes of the first-stage digester are different from those of the second and third-stage digesters (see attached diagram). Figure 3 The first-stage digester uses full-width fan-shaped blades to achieve uniform mixing of materials and most of the digestion. The second and third-stage digesters use irregularly shaped stirring blades to make the mixing of materials more vigorous, ensuring the complete completion of the digestion reaction.

[0038] 10. This invention, with its small-scale mobile high-activity calcium-based desulfurizer preparation device, offers the advantage of flexible preparation. It meets diverse placement requirements, allowing for easy relocation of the production site, and caters to the need for convenient small-batch experimental preparation of calcium-based desulfurizer in industrial settings. Attached Figure Description

[0039] Figure 1 Flowchart for the preparation of highly active calcium-based desulfurizer;

[0040] Figure 2 A three-dimensional structural diagram of a small-scale mobile high-activity calcium-based desulfurizing agent preparation device;

[0041] Figure 3 A schematic cross-sectional view of a small-scale mobile high-activity calcium-based desulfurizer preparation device;

[0042] Figure 4 Flowchart of fixed-bed desulfurization reaction test;

[0043] Explanation of reference numerals in the attached diagram: 1. Feed inlet; 2. First-stage digester; 3. Second-stage digester; 4. Third-stage digester; 5. Atomizing nozzle; 6. Liquid injection port; 7. Spray control system; 8. Spiral stirring propulsion shaft; 9. Heating layer; 10. Oil injection port; 11. Temperature control device; 12. Discharge port; 13. Ball valve; 14. Support frame; 15. Casters. Detailed Implementation

[0044] Example 1

[0045] like Figure 1 , 2 As shown, the present invention provides a small-scale mobile high-activity calcium-based desulfurizer preparation device and preparation method, comprising the following steps:

[0046] (1) Industrial quicklime powder produced from a rotary kiln has high activity. Quicklime and aluminum hydroxide powder are weighed and added to a small, mobile, high-activity calcium-based desulfurizer preparation device at a set feeding rate. The digester consists of three stages, each with an adjustable-speed twin-shaft spiral stirring and propulsion rod. Atomizing nozzles are evenly arranged at the top of the first and second stage digesters, and the spray flow rate can be controlled separately by the spraying device. The mass ratio of quicklime to aluminum hydroxide is 1:0.1.

[0047] (2) The twin-shaft helical propeller inside the first-stage digester rotates uniformly at a given rate. The mixture of quicklime and calcium hydroxide powder from step (1) is uniformly mixed under the stirring of the agitator blades, and the first-stage digestion liquid is simultaneously introduced. The first-stage digestion liquid sprayed from the atomizing nozzle fully contacts and reacts with the mixture. The digestate reacts in the first-stage digester for 10 minutes and is then pushed into the second-stage digester. The calcium chloride content in the digestion liquid is 4 wt.%, the mass ratio of digestion liquid to powder is 1:1, and the temperature of the digestion liquid is 60°C. The bottom and sides of the first-stage digester are equipped with heating layers, and the temperature is set to 100°C by a temperature control device.

[0048] (3) The twin-shaft helical propeller inside the second-stage digester rotates uniformly at a given rate, and the digestate from step (2) is stirred by irregularly shaped impeller blades (attached). Figure 3 The mixture is stirred more vigorously, and a secondary digestive solution is introduced. The secondary digestive solution, sprayed from the atomizing nozzle, comes into uniform contact with the digestate, causing further digestion. After reacting in the second-stage digester for 10 minutes, the digestate is pushed into the third-stage digester. The digestive solution contains 2 wt.% urea, the mass ratio of digestive solution to powder is 1:1, and the temperature of the digestive solution is 60°C. The second-stage digester has heating layers at the bottom and sides, and the temperature is set to 100°C by a temperature control device.

[0049] (4) The twin-shaft helical propeller inside the third-stage digester rotates uniformly at a given rate, and the digestate from step (3) is stirred by irregularly shaped impeller blades (attached). Figure 3 The mixture is vigorously stirred and matured under stirring. After 20 minutes, the ball valve at the discharge port is opened, and the digestate is pushed out of the preparation device to obtain a fluffy, highly active calcium-based desulfurizing agent product. The third-stage digester is equipped with heating layers at the bottom and sides, and the temperature is set to 100℃ by a temperature control device.

[0050] (5) After grinding the high-activity calcium-based desulfurizing agent obtained in step (4) to 120 mesh, its performance is tested on a fixed-bed desulfurization reactor (see attached). Figure 4 The drug loading amount was set at 0.25g, and the sulfur dioxide concentration at 120mg / m³. 3The reaction temperature was 100℃, the oxygen content was 5%, and the total gas flow rate was 1L / min. The penetration efficiency was set to half of the maximum desulfurization efficiency. Experimental results showed that the highly active calcium-based desulfurizer achieved a desulfurization efficiency of 100%, a penetration time of 80 min, and a penetration sulfur capacity of 34.13 mg / g. This penetration sulfur capacity is approximately 42 times that of industrial quicklime (0.81 mg / g). BET test results showed that the specific surface area of ​​this desulfurizer was as high as 22.1003 m². 2 / g, pore volume is 0.0964cm³ 3 / g, with an average pore size of 12.6962nm.

[0051] Example 2

[0052] like Figure 1 , 2 As shown, the present invention provides a small-scale mobile high-activity calcium-based desulfurizer preparation device and preparation method, comprising the following steps:

[0053] (1) Industrial quicklime powder produced from a rotary kiln has high activity. Quicklime and ferric oxide powder are weighed and added to a small, mobile, high-activity calcium-based desulfurizer preparation device at a set feeding rate. The digester consists of three stages, each with a built-in adjustable-speed twin-shaft spiral stirring and propulsion rod. Atomizing nozzles are evenly arranged at the top of the first and second stage digesters, and the spray flow rate can be controlled separately by the spraying device. The mass ratio of quicklime to ferric oxide is 1:0.1.

[0054] (2) The twin-shaft helical propeller inside the first-stage digester rotates uniformly at a given rate. The mixture of quicklime and ferric oxide powder from step (1) is uniformly mixed under the stirring of the agitator blades, while the first-stage digestion liquid is introduced. The first-stage digestion liquid sprayed from the atomizing nozzle fully contacts and reacts with the mixture. The digestate reacts in the first-stage digester for 15 minutes and is then pushed into the second-stage digester. The content of calcium chloride in the digestion liquid is 2 wt.%, the mass ratio of digestion liquid to powder is 1:0.4, and the temperature of the digestion liquid is 25°C. The bottom and sides of the first-stage digester are equipped with heating layers, and the temperature is set to 50°C by a temperature control device.

[0055] (3) The twin-shaft helical propeller inside the second-stage digester rotates uniformly at a given rate, and the digestate from step (2) is stirred by irregularly shaped impeller blades (attached). Figure 3The mixture is stirred more vigorously, and a secondary digestion solution is introduced simultaneously. The secondary digestion solution, sprayed from the atomizing nozzle, comes into uniform contact with the digestate, causing further digestion. After reacting in the second-stage digester for 15 minutes, the digestate is pushed into the third-stage digester. The digestion solution contains 2 wt.% 1,3-butanediol, the mass ratio of digestion solution to powder is 1:0.4, and the temperature of the digestion solution is 25°C. The second-stage digester has heating layers at the bottom and sides, and the temperature is set to 50°C via a temperature control device.

[0056] (4) The twin-shaft helical propeller inside the third-stage digester rotates uniformly at a given rate, and the digestate from step (3) is stirred by irregularly shaped impeller blades (attached). Figure 3 The mixture is vigorously stirred and matured under stirring. After 25 minutes, the ball valve at the discharge port is opened, and the digestate is pushed out of the preparation device to obtain a fluffy, highly active calcium-based desulfurizing agent product. The third-stage digester is equipped with heating layers at the bottom and sides, and the temperature is set to 80℃ by a temperature control device.

[0057] (5) After grinding the high-activity calcium-based desulfurizing agent obtained in step (4) to 120 mesh, its performance is tested on a fixed-bed desulfurization reactor. The reagent loading amount is set to 0.6g, and the sulfur dioxide concentration is set to 500mg / m³. 3 The reaction temperature was 100℃, the oxygen content was 5%, and the total gas flow rate was 1L / min. The penetration efficiency was set to half of the maximum desulfurization efficiency. Experimental results showed that the highly active calcium-based desulfurizer achieved a desulfurization efficiency of 100%, a penetration time of 55 min, and a penetration sulfur capacity of 37.24 mg / g. This penetration sulfur capacity is approximately 46 times that of industrial quicklime (0.81 mg / g). BET test results showed that the specific surface area of ​​this desulfurizer was as high as 19.6080 m². 2 / g, pore volume is 0.1250cm³ 3 / g, with an average pore size of 26.4327nm.

[0058] Example 3

[0059] 1) Industrial quicklime powder produced from a rotary kiln has high activity. Quicklime and ferric oxide powder are weighed and added to a small, mobile, high-activity calcium-based desulfurizer preparation device at a set feeding rate. The digester consists of three stages, each with an adjustable-speed twin-shaft spiral stirring and propulsion rod. Atomizing nozzles are evenly arranged at the top of the first and second stages of the digester, and the spray flow rate can be controlled separately by the spraying device. The mass ratio of quicklime to magnesium oxide is 1:0.05.

[0060] (2) The twin-shaft helical propeller inside the first-stage digester rotates uniformly at a given rate. The mixture of quicklime and magnesium oxide powder from step (1) is uniformly mixed under the stirring of the agitator blades, while the first-stage digestion liquid is introduced. The first-stage digestion liquid sprayed from the atomizing nozzle fully contacts and reacts with the mixture. The digestate reacts in the first-stage digester for 10 minutes and is then pushed into the second-stage digester. The content of calcium chloride in the digestion liquid is 2 wt.%, the mass ratio of digestion liquid to powder is 1:0.8, and the temperature of the digestion liquid is 60°C. The bottom and sides of the first-stage digester are equipped with heating layers, and the temperature is set to 50°C by a temperature control device.

[0061] (3) The twin-shaft helical propeller inside the second-stage digester rotates uniformly at a given rate, and the digestate from step (2) is stirred by irregularly shaped impeller blades (attached). Figure 3 The mixture is stirred more vigorously, and a secondary digestive solution is introduced. The secondary digestive solution, sprayed from the atomizing nozzle, comes into uniform contact with the digestate, causing further digestion. After reacting in the second-stage digester for 10 minutes, the digestate is pushed into the third-stage digester. The digestive solution contains 2 wt.% sodium hydroxide and urea, with a digestive solution to powder mass ratio of 1:0.5, and a temperature of 60°C. The second-stage digester has heating layers at the bottom and sides, with the temperature set to 50°C via a temperature control device.

[0062] (4) The twin-shaft helical propeller inside the third-stage digester rotates uniformly at a given rate, and the digestate from step (3) is stirred by irregularly shaped impeller blades (attached). Figure 3 The mixture is vigorously stirred and matured under stirring. After 30 minutes, the ball valve at the discharge port is opened, and the digestate is pushed out of the preparation device to obtain a fluffy, highly active calcium-based desulfurizing agent product. The third-stage digester is equipped with heating layers at the bottom and sides, and the temperature is set to 80℃ by a temperature control device.

[0063] (5) After grinding the high-activity calcium-based desulfurizing agent obtained in step (4) to 120 mesh, its performance is tested on a fixed-bed desulfurization reactor. The reagent loading amount is set to 0.3g, and the sulfur dioxide concentration is set to 200mg / m³. 3 The reaction temperature was 100℃, the oxygen content was 5%, and the total gas flow rate was 1L / min. The penetration efficiency was set to half of the maximum desulfurization efficiency. Experimental results showed that the desulfurization efficiency of this highly active calcium-based desulfurizer was 95.89%, the penetration time was 36 min, and the penetration sulfur capacity was 16.21 mg / g. The penetration sulfur capacity is approximately 20 times that of industrial quicklime (0.81 mg / g). BET test results showed that the specific surface area of ​​this desulfurizer was as high as 23.5740 m². 2 / g, pore volume is 0.1319cm³ 3 / g, with an average pore size of 23.4880nm.

[0064] Example 4

[0065] The urea solution concentration used in step (3) of Example 1 was replaced with 5 wt.% to obtain a desulfurizing agent sample. The reagent loading amount was set to 0.5 g, and the sulfur dioxide concentration was 120 mg / m³. 3 The reaction temperature was 100℃, the oxygen content was 5%, and the total gas flow rate was 1L / min. The penetration efficiency was set to half of the maximum desulfurization efficiency. Experimental results showed that the highly active calcium-based desulfurizer achieved a desulfurization efficiency of 100%, a penetration time of 63 min, and a penetration sulfur capacity of 17.36 mg / g. This penetration sulfur capacity is approximately 21 times that of industrial quicklime (0.81 mg / g). BET testing results showed that the specific surface area of ​​this desulfurizer was as high as 20.7938 m². 2 / g, pore volume is 0.1154cm³ 3 / g, with an average pore size of 16.8155nm.

[0066] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a highly active calcium-based desulfurizing agent, characterized in that, Includes the following steps: S1. Industrial quicklime powder and highly active metal oxide are mixed at a mass ratio of 1:(0.05~0.1) and fed into the feed inlet; the highly active metal oxide is one or more of aluminum oxide, magnesium oxide, and ferric oxide; The mixture of materials S2 and S1 is stirred and mixed by the stirring blades in the first-stage digester, and at the same time, it comes into full contact with the primary digesting liquid sprayed from the atomizing nozzle. Primary digestion is carried out at 50~100℃, and after staying for 10-15 minutes, it is pushed into the second-stage digester. The primary digesting liquid is an inorganic salt solution containing 1~4 wt.% chloride ions, and the inorganic salt is one of calcium chloride, magnesium chloride, potassium chloride, and sodium chloride. In S3 and S2, the digestate is stirred and mixed by the agitator blades in the second-stage digester, and simultaneously comes into full contact with the secondary digestion liquid sprayed from the atomizing nozzle. Secondary digestion is carried out at 50~100℃, and after 10-15 minutes, it is pushed into the third-stage digester. The secondary digestion liquid is a mixture of deionized water and organic solvent, wherein the organic solvent accounts for 1.5~5 wt.%, and the organic solvent is one or more of diethylene glycol, 1,3-butanediol, urea, polyethylene glycol, and ethylene glycol. The digests in S4 and S3 are stirred and matured by the stirring blades in the third-stage digester. After being held at 80~120℃ for 20-25 minutes, they are discharged from the outlet to obtain fluffy, highly active calcium-based desulfurizer powder. The mass ratio of the primary digestion liquid in S2 to the quicklime raw material in S1 is 1:(0.4~1), the mass ratio of the secondary digestion liquid in S3 to the quicklime raw material in S1 is 1:(0.4~1), and the temperature of the primary and secondary digestion liquids is 25~60℃ respectively.

2. The preparation method according to claim 1, characterized in that, The quicklime mentioned in S1 is industrial powdered quicklime produced from a rotary kiln, with a calcium content greater than 90%.

3. The preparation method according to claim 1, characterized in that, The inorganic salt mentioned in S2 is calcium chloride.

4. The preparation method according to claim 1, characterized in that, The organic solvent mentioned in S3 is urea.

5. The preparation method according to claim 1, characterized in that, The mass ratio of primary digestion liquid in S2 to quicklime raw material in S1 is 1:1, and the mass ratio of secondary digestion liquid in S3 to quicklime raw material in S1 is 1:

1.

6. The preparation method according to claim 1, characterized in that, The preparation apparatus used includes a feed inlet (1), a first-stage digester (2), a second-stage digester (3), a third-stage digester (4), an atomizing nozzle (5), a liquid injection port (6), a spray control system (7), a dual-shaft spiral propeller (8), a heating layer (9), an oil injection port (10), a temperature control device (11), a discharge port (12), a ball valve (13), a support (14), and casters (15). The feed inlet (1) is used to feed the mixture of industrial quicklime powder and highly active metal oxide as described in claim 1 S1 into the device; The first-stage digester (2), the second-stage digester (3), and the third-stage digester (4) are stacked vertically and connected end to end. The stirring shafts of each layer run in opposite directions and the stirring shafts are designed as parallel double shafts. The first-stage digester (2) is equipped with horizontally uniformly distributed atomizing nozzles (5) on its top for spraying the primary digestion liquid as described in claim 1 S2; the second-stage digester (3) is equipped with horizontally uniformly distributed atomizing nozzles (5) on its top for spraying the secondary digestion liquid as described in claim 1 S3; the spraying range and flow rate of each atomizing nozzle (5) are independently controlled by the spraying control system (7), and the primary digestion liquid required by the first-stage digester (2) and the secondary digestion liquid required by the second-stage digester (3) are added from different injection ports (6); The first-stage digester (2) uses regularly shaped stirring blades to achieve uniform mixing of the mixture material described in claim 1 S2 with the primary digest liquid; the second-stage digester (3) and the third-stage digester (4) use irregularly shaped stirring blades to achieve enhanced stirring and maturation of the digestate described in claims 1 S3 and S4. The temperature control device (11) independently controls the heating temperature of the first digester (2), the second digester (3), and the third digester (4) to achieve the graded temperature control of 50~100℃ in S2 and S3 and 80~120℃ in S4 in claim 1; the heat transfer oil in the interlayer of each heating layer (9) is added through its respective oil inlet (10); The bracket (14) is fitted with casters (15) at its bottom.

7. The preparation method according to claim 6, characterized in that, The first-stage digester (2) of the preparation device uses regularly shaped stirring blades, while the second-stage digester (3) and the third-stage digester (4) use irregularly shaped stirring blades, so as to achieve an increasing stirring intensity in the first-stage digester (2), the second-stage digester (3), and the third-stage digester (4).

8. The preparation method according to claim 6, characterized in that, The first-stage digester (2), second-stage digester (3), and third-stage digester (4) of the preparation device are equipped with frequency-converting dual-axis spiral propellers (8) at the center of their cavities. The bottom arc-shaped heating layer (9) is in close contact with the stirring range of the blades of the dual-axis spiral propellers (8), and the digestion reaction time is controlled by the motor speed.

9. The preparation method according to claim 6, characterized in that, The preparation device has an arc-shaped heating layer (9) at the bottom and on the left and right sides of the three-stage digester stirring tank. The temperature control device (11) can set the temperature of the first-stage digester (2), the second-stage digester (3), and the third-stage digester (4) in stages. The heat-conducting oil in the interlayer of the heating layer (9) is added through the oil inlet (10).

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