A desulfurization catalyst made from ferric oxyhydroxide produced as a byproduct of titanium dioxide, and a preparation method thereof

Abstract

A ferric oxyhydroxide desulfurization catalyst prepared using green vitriol, a by-product of titanium dioxide, and a preparation method thereof belong to the technical field of catalysts. The preparation method of the ferric oxyhydroxide desulfurization catalyst prepared using green vitriol, a by-product of titanium dioxide, comprises two steps: preparing ferric oxyhydroxide and preparing the ferric oxyhydroxide desulfurization catalyst. The ferric oxyhydroxide desulfurization catalyst prepared using green vitriol, a by-product of titanium dioxide, has a breakthrough sulfur capacity of 40.1-43.4%.

Description

Technical Field

[0001] The invention relates to an iron oxyhydroxide desulfurization catalyst prepared by utilizing green vitriol, a byproduct of titanium dioxide, and a preparation method thereof, belonging to the technical field of catalysts. Background Art

[0002] Sulfides are produced in many situations in industrial production. For example, in the production process of chemical raw materials from coal or oil, and in the wastewater or exhaust gas discharged from ordinary industrial production, there are many sulfur-containing substances, and they mainly exist in the form of hydrogen sulfide. Hydrogen sulfide is highly toxic and not only affects human health, but also causes serious problems in industrial application scenarios such as pipelines, equipment and catalysts. Therefore, industrial desulfurizers, especially high-performance desulfurizers specifically for hydrogen sulfide removal, have always been popular products that the industry has focused on researching and developing.

[0003] Ferric oxyhydroxide desulfurization is a traditional gas purification method with relatively mature technology. It is also resource-rich and inexpensive. It has a very high theoretical sulfur penetration capacity (54.12%) at room temperature, making it widely used in room-temperature desulfurization. The raw materials for preparing oxyhydroxide are mostly ferrous salts, such as ferrous chloride, ferrous nitrate, and ferrous sulfate. Among them, oxyhydroxide prepared from ferrous sulfate heptahydrate has relatively high desulfurization performance. According to published laboratory data, the sulfur penetration capacity of oxyhydroxide synthesized from ferrous sulfate heptahydrate can reach 51.38%. The amount of desulfurizer used is very large. Currently, in order to obtain more cost-effective ferrous sulfate heptahydrate, the industry has focused its research and development on the titanium dioxide byproduct, green vitriol. For every ton of titanium dioxide produced, 3 to 4 tons of green vitriol are produced, and the content of ferrous sulfate heptahydrate in green vitriol is often above 80%. Furthermore, the titanium dioxide byproduct contains TiO 2+ 、Mn 2+ Mg 2+ 、Al 3+ Impurities such as green vitriol have no adverse effects on the desulfurization reaction. Since the production capacity of titanium dioxide is at the million-ton level, the use of titanium dioxide by-product green vitriol to prepare iron oxyhydroxide has significant advantages such as abundant raw materials, low price and no need for purification.

[0004] Although the use of green vitriol, a titanium dioxide byproduct, to prepare ferric oxyhydroxide can transform waste into valuable resources and achieve solid waste resource utilization, the desulfurization performance of ferric oxyhydroxide prepared from green vitriol, a titanium dioxide byproduct, is currently unsatisfactory. For example, Chinese patent CN114768837A discloses an ferric oxyhydroxide desulfurization catalyst prepared from green vitriol, a titanium dioxide byproduct, and a preparation method thereof. The catalyst comprises the following components by weight: 25-35% ferric oxyhydroxide, 55-65% calcium sulfate dihydrate, and 4-20% other components. The preparation method comprises mixing green vitriol, a titanium dioxide byproduct, with industrial calcium hydroxide, reacting the mixture by rolling, extruding the resulting strips, and then air-drying them. The ferric oxyhydroxide desulfurization catalyst prepared in this invention uses ferric oxyhydroxide synthesized from green vitriol, a titanium dioxide byproduct, as the primary component, with calcium sulfate dihydrate and other components as the remaining components. This fully utilizes the green vitriol, a titanium dioxide byproduct, and reduces raw material costs. However, the maximum sulfur penetration capacity of the ferric oxyhydroxide desulfurization catalyst obtained in this patent is only 16.2%, far lower than the theoretical sulfur penetration capacity of ferric oxyhydroxide and the actual sulfur penetration capacity achievable in the laboratory.

[0005] It can be seen that the iron oxyhydroxide desulfurization catalyst prepared using titanium dioxide by-product green vitriol has extremely high industrial application value, but it still needs to solve the prominent problem of low penetration sulfur capacity to make it more suitable for large-scale and low-cost applications in the industrial field. Summary of the Invention

[0006] In view of the shortcomings of the above-mentioned prior art, the present invention provides an iron oxyhydroxide desulfurization catalyst prepared using titanium dioxide by-product green vitriol and a preparation method thereof, to achieve the following invention objectives: using titanium dioxide by-product green vitriol to prepare an iron oxyhydroxide desulfurization catalyst with very high room temperature penetration sulfur capacity.

[0007] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0008] A ferric oxyhydroxide desulfurization catalyst prepared using green vitriol, a byproduct of titanium dioxide, and a preparation method thereof. The ferric oxyhydroxide desulfurization catalyst prepared using green vitriol, a byproduct of titanium dioxide, has a breakthrough sulfur capacity of 40.1-43.4%.

[0009] The method for preparing the iron oxyhydroxide desulfurization catalyst using the titanium dioxide byproduct green vitriol comprises two steps: preparing the iron oxyhydroxide and preparing the iron oxyhydroxide desulfurization catalyst;

[0010] The following are further improvements to the above technical solution:

[0011] Step 1: Preparation of iron oxyhydroxide

[0012] The titanium dioxide byproduct, green vitriol, and deionized water are placed in a reactor, stirred and dissolved under nitrogen protection, and after complete dissolution, a composite precipitant is added dropwise to control the pH of the solution in the reactor to be between 6 and 7.8. After the addition of the composite precipitant is completed, peroxide is added and the nitrogen is switched to air. Air is continuously introduced and stirred to carry out an oxidation reaction. When the color of the solution in the reactor no longer changes, the air introduction and stirring are stopped, the material is filtered, and the filtrate is washed and dried to obtain ferric oxyhydroxide.

[0013] The composite precipitant is obtained by mixing and dissolving a diamine substance, a quaternary ammonium base and deionized water;

[0014] The diamine substance is one or a mixture of 2-hydroxyethylamine and ethylenediamine in any mass ratio;

[0015] The quaternary ammonium base is one or any two of tetramethylammonium hydroxide, tetraethylammonium hydroxide, hexamethonium hydroxide, tetrabutylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylphosphonium hydroxide, or a mixture of any two or more of them in any mass ratio;

[0016] The peroxide is one of calcium peroxide, magnesium peroxide, potassium peroxide, sodium peroxide, and zinc peroxide, or a mixture of any two of them in any mass ratio, or any two or more of them in any mass ratio;

[0017] The mass ratio of the diamine substance, quaternary ammonium base and deionized water is 7-19:5-30:90-250;

[0018] The mass ratio of the titanium dioxide byproduct green vitriol, deionized water, composite precipitant, and peroxide is 50-120:160-390:25-80:1-6;

[0019] The continuous introduction of air and stirring, the air flow rate is 40-100 L / h, and the stirring rate is 500-900 rpm;

[0020] The washing step comprises washing with deionized water until the pH value of the washing solution is neutral;

[0021] The drying step is performed at 80-100° C. for 7-13 hours.

[0022] Step 2: Preparation of iron oxyhydroxide desulfurization catalyst

[0023] Iron oxyhydroxide, an active accelerator, calcium bentonite, sodium carboxymethyl cellulose, and deionized water are placed in a double planetary mixer, stirred and dispersed into a paste, and then transferred to an extruder to extrude long strip particles, which are then dried to obtain a strip-shaped iron oxyhydroxide desulfurization catalyst;

[0024] The active promoter is one of copper bismuthate and sodium bismuthate, or a mixture of the two in any mass ratio;

[0025] The mass ratio of the ferric oxyhydroxide, active accelerator, calcium bentonite, sodium carboxymethyl cellulose and deionized water is 40-90:5-13:90-240:4-10:25-50;

[0026] The stirring and dispersing process has a stirring rate of 100 to 150 rpm and a dispersion rate of 5000 to 9000 rpm;

[0027] The elongated particles have a cross-sectional diameter of 2 to 6 mm and a length of 8 to 20 mm;

[0028] The drying temperature is 50-65° C. and the drying time is 25-44 hours.

[0029] Compared with the prior art, the present invention achieves the following beneficial effects:

[0030] 1. The present invention uses a quaternary ammonium base and a diamine substance to form a composite precipitant. The composite precipitant formed by the combination of these two substances can not only more accurately control the pH fluctuation range of the reaction system, providing a stable pH fluctuation range for the uniform precipitation of iron ions, but also form a certain degree of complex adsorption effect with iron ions, accelerate the precipitation rate of iron ions, make the particle size smaller and more uniform, which will also promote its particle size to develop towards the nanoscale, and ultimately promote a significant increase in the specific surface area of ferric oxyhydroxide;

[0031] 2. The present invention uses peroxide and air, two oxidizing substances, to rapidly and fully oxidize the iron ion precipitate. The oxygen free radicals generated by the decomposition of peroxide in water greatly enhance the oxidizing effect of oxygen in the air. The oxygen free radicals generated by the peroxide and the oxygen in the air combine to form a strong oxidizing effect, which promotes the efficiency and uniformity of the oxidation reaction in the system, thereby obtaining iron oxyhydroxide with a finer particle size, so that the size of the iron oxyhydroxide particles reaches the nanometer scale, ultimately ensuring the specific surface area and high catalytic activity of the iron oxyhydroxide, that is, maximizing the sulfur penetration capacity of the catalyst;

[0032] 3. The copper bismuthate and sodium bismuthate added in the present invention serve as active promoters of the ferric oxyhydroxide desulfurization catalyst and may form a composite oxide with the ferric oxyhydroxide. This composite oxide has a certain effect on improving the ability of the ferric oxyhydroxide to bind sulfur, thereby improving the desulfurization reaction activity and ultimately increasing the sulfur penetration capacity of the ferric oxyhydroxide desulfurizer.

[0033] 4. The iron oxyhydroxide desulfurization catalyst prepared by using the titanium dioxide by-product green vitriol obtained in the present invention has a breakthrough sulfur capacity of 40.1~43.4%. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a scanning electron microscope photograph of the iron oxyhydroxide obtained in step 1 of Example 1, magnified 10,000 times;

[0035] Figure 2 This is a scanning electron microscope photograph of the iron oxyhydroxide obtained in step 1 of Example 1, with its surface magnified 50,000 times. DETAILED DESCRIPTION

[0036] The preferred embodiments of the present invention are described below. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0037] Example 1: A method for preparing an iron oxyhydroxide desulfurization catalyst using a titanium dioxide byproduct, green vitriol

[0038] Step 1: Preparation of iron oxyhydroxide

[0039] The titanium dioxide byproduct, green vitriol, and deionized water are placed in a reactor, stirred and dissolved under nitrogen protection, and after complete dissolution, a composite precipitant is added dropwise to control the pH of the solution in the reactor to 6.8. After the addition of the composite precipitant is completed, peroxide is added, and the nitrogen is switched to air. Air is continuously introduced and stirred to carry out an oxidation reaction. When the color of the solution in the reactor no longer changes, the air introduction and stirring are stopped, the material is filtered, and the filtrate is washed and dried to obtain ferric oxyhydroxide.

[0040] The composite precipitant is obtained by mixing and dissolving a diamine substance, a quaternary ammonium base and deionized water;

[0041] The diamine substance is 2-hydroxyethylamine;

[0042] The quaternary ammonium base is tetramethylammonium hydroxide;

[0043] The peroxide is calcium peroxide;

[0044] The mass ratio of the diamine substance, quaternary ammonium base and deionized water is 11:20:180;

[0045] The mass ratio of the titanium dioxide byproduct green vitriol, deionized water, composite precipitant, and peroxide is 90:300:60:5;

[0046] The continuous introduction of air and stirring had an air flow rate of 55 L / h and a stirring rate of 800 rpm;

[0047] The washing step comprises washing with deionized water until the pH value of the washing solution is neutral;

[0048] The drying was carried out at 90° C. for 11 hours.

[0049] Step 2: Preparation of iron oxyhydroxide desulfurization catalyst

[0050] Iron oxyhydroxide, an active accelerator, calcium bentonite, sodium carboxymethyl cellulose, and deionized water are placed in a double planetary mixer, stirred and dispersed into a paste, and then transferred to an extruder to extrude long strip particles, which are then dried to obtain a strip-shaped iron oxyhydroxide desulfurization catalyst;

[0051] The active promoter is copper bismuthate;

[0052] The mass ratio of the ferric oxyhydroxide, active accelerator, calcium bentonite, sodium carboxymethyl cellulose and deionized water is 70:11:150:7:40;

[0053] The stirring and dispersing process has a stirring rate of 120 rpm and a dispersing rate of 8000 rpm;

[0054] The elongated particles have a cross-sectional diameter of 5 mm and a length of 18 mm;

[0055] The drying temperature is 60° C. and the drying time is 35 hours.

[0056] Example 2: A method for preparing an iron oxyhydroxide desulfurization catalyst using a titanium dioxide byproduct, green vitriol

[0057] Step 1: Preparation of iron oxyhydroxide

[0058] The titanium dioxide byproduct, green vitriol, and deionized water are placed in a reactor, stirred and dissolved under nitrogen protection, and after complete dissolution, a composite precipitant is added dropwise to control the pH of the solution in the reactor to 6. After the addition of the composite precipitant is completed, peroxide is added and the nitrogen is switched to air. Air is continuously introduced and stirred to carry out an oxidation reaction. When the color of the solution in the reactor no longer changes, the air introduction and stirring are stopped, the material is filtered, and the filtrate is washed and dried to obtain ferric oxyhydroxide.

[0059] The composite precipitant is obtained by mixing and dissolving a diamine substance, a quaternary ammonium base and deionized water;

[0060] The diamine substance is ethylenediamine;

[0061] The quaternary ammonium base is tetraethylammonium hydroxide;

[0062] The peroxide is magnesium peroxide;

[0063] The mass ratio of the diamine substance, quaternary ammonium base and deionized water is 7:5:90;

[0064] The mass ratio of the titanium dioxide byproduct green vitriol, deionized water, composite precipitant, and peroxide is 50:160:25:1;

[0065] The continuous introduction of air and stirring was carried out at an air flow rate of 40 L / h and a stirring rate of 500 rpm;

[0066] The washing step comprises washing with deionized water until the pH value of the washing solution is neutral;

[0067] The drying was carried out at 80° C. for 7 hours.

[0068] Step 2: Preparation of iron oxyhydroxide desulfurization catalyst

[0069] Iron oxyhydroxide, an active accelerator, calcium bentonite, sodium carboxymethyl cellulose, and deionized water are placed in a double planetary mixer, stirred and dispersed into a paste, and then transferred to an extruder to extrude long strip particles, which are then dried to obtain a strip-shaped iron oxyhydroxide desulfurization catalyst;

[0070] The active promoter is sodium bismuthate;

[0071] The mass ratio of the ferric oxyhydroxide, active accelerator, calcium bentonite, sodium carboxymethyl cellulose and deionized water is 40:5:90:4:25;

[0072] The stirring and dispersing process has a stirring rate of 100 rpm and a dispersing rate of 5000 rpm;

[0073] The elongated particles have a cross-sectional diameter of 2 mm and a length of 8 mm;

[0074] The drying temperature is 50° C. and the drying time is 25 hours.

[0075] Example 3: A method for preparing an iron oxyhydroxide desulfurization catalyst using a titanium dioxide byproduct, green vitriol

[0076] Step 1: Preparation of iron oxyhydroxide

[0077] The titanium dioxide byproduct, green vitriol, and deionized water are placed in a reactor, stirred and dissolved under nitrogen protection, and after complete dissolution, a composite precipitant is added dropwise to control the pH of the solution in the reactor to 7.8. After the addition of the composite precipitant is completed, peroxide is added and the nitrogen is switched to air. Air is continuously introduced and stirred to carry out an oxidation reaction. When the color of the solution in the reactor no longer changes, the air introduction and stirring are stopped, the material is filtered, and the filtrate is washed and dried to obtain ferric oxyhydroxide.

[0078] The composite precipitant is obtained by mixing and dissolving a diamine substance, a quaternary ammonium base and deionized water;

[0079] The diamine substance is 2-hydroxyethylamine;

[0080] The quaternary ammonium base is hexamethonium hydroxide;

[0081] The peroxide is potassium peroxide;

[0082] The mass ratio of the diamine substance, quaternary ammonium base and deionized water is 19:30:250;

[0083] The mass ratio of the titanium dioxide byproduct green vitriol, deionized water, composite precipitant, and peroxide is 120:390:80:6;

[0084] The continuous introduction of air and stirring was performed with an air flow rate of 100 L / h and a stirring rate of 900 rpm;

[0085] The washing step comprises washing with deionized water until the pH value of the washing solution is neutral;

[0086] The drying was carried out at 100° C. for 13 hours.

[0087] Step 2: Preparation of iron oxyhydroxide desulfurization catalyst

[0088] Iron oxyhydroxide, an active accelerator, calcium bentonite, sodium carboxymethyl cellulose, and deionized water are placed in a double planetary mixer, stirred and dispersed into a paste, and then transferred to an extruder to extrude long strip particles, which are then dried to obtain a strip-shaped iron oxyhydroxide desulfurization catalyst;

[0089] The active promoter is copper bismuthate;

[0090] The mass ratio of the ferric oxyhydroxide, active accelerator, calcium bentonite, sodium carboxymethyl cellulose and deionized water is 90:13:240:10:50;

[0091] The stirring and dispersing process has a stirring rate of 150 rpm and a dispersing rate of 9000 rpm;

[0092] The elongated particles have a cross-sectional diameter of 6 mm and a length of 20 mm;

[0093] The drying temperature is 65° C. and the drying time is 44 hours.

[0094] Example 4: A method for preparing an iron oxyhydroxide desulfurization catalyst using a titanium dioxide byproduct, green vitriol

[0095] Step 1: Preparation of iron oxyhydroxide

[0096] The quaternary ammonium base is tetrabutylammonium hydroxide;

[0097] The peroxide is sodium peroxide;

[0098] Other operations are the same as in Example 1;

[0099] The operation of step 2 is the same as that of embodiment 1.

[0100] Example 5: A method for preparing an iron oxyhydroxide desulfurization catalyst using a titanium dioxide byproduct, green vitriol

[0101] Step 1: Preparation of iron oxyhydroxide

[0102] The quaternary ammonium base is tetrapropylammonium hydroxide;

[0103] The peroxide is zinc peroxide;

[0104] Other operations are the same as in Example 1;

[0105] The operation of step 2 is the same as that of embodiment 1.

[0106] Example 6: A method for preparing an iron oxyhydroxide desulfurization catalyst using a titanium dioxide byproduct, green vitriol

[0107] Step 1: Preparation of iron oxyhydroxide

[0108] The quaternary ammonium base is tetrabutyl phosphine hydroxide;

[0109] Other operations are the same as in Example 1;

[0110] The operation of step 2 is the same as that of embodiment 1.

[0111] Comparative Example 1: Based on Example 1, in step 1, in preparing iron oxyhydroxide, the composite precipitant was replaced with ammonia water, and the specific operation was as follows:

[0112] Step 1: Preparation of iron oxyhydroxide

[0113] The composite precipitant was replaced with ammonia water, and the other operations were the same as in Example 1;

[0114] The operation of step 2 is the same as that of embodiment 1.

[0115] Comparative Example 2: Based on Example 1, in step 1, no peroxide is added in the preparation of iron oxyhydroxide, and the specific operation is as follows:

[0116] Step 1: Preparation of iron oxyhydroxide

[0117] No peroxide was added, and other operations were the same as in Example 1;

[0118] The operation of step 2 is the same as that of embodiment 1.

[0119] Comparative Example 3: Based on Example 1, in step 2, preparing the iron oxyhydroxide desulfurization catalyst, 11 parts of the active promoter were replaced by 11 parts of iron oxyhydroxide. The specific operation was as follows:

[0120] The operation of step 1 is the same as that of Example 1;

[0121] Step 2: Preparation of iron oxyhydroxide desulfurization catalyst

[0122] The 11 parts of active accelerator were replaced by 11 parts of ferric oxyhydroxide, and the other operations were the same as in Example 1.

[0123] Performance testing:

[0124] The iron oxyhydroxide desulfurization catalyst prepared from the titanium dioxide by-product green vitriol obtained in Examples 1, 2, 3, 4, 5, 6 and Comparative Examples 1, 2, 3 was placed in a fixed bed reactor of a hard quartz tube with a diameter of φ10 mm×200 mm (diameter×length), and the upper and lower ends of the catalyst were filled with quartz sand. The reactor was heated at room temperature, normal pressure, and a gas space velocity of 1000 h -1 The catalyst desulfurization activity test was carried out under the conditions of , and the breakthrough sulfur capacity of the iron oxyhydroxide desulfurization catalyst was examined. The H2S content at the outlet of the desulfurization reactor was analyzed using an Agilent GC 7890A chromatograph and an H2S rapid detection tube. The breakthrough sulfur capacity test condition was that the H2S volume fraction in the inlet feed gas was 1.0%. When the outlet H2S volume fraction exceeded 0.5ppm, it was considered that breakthrough had occurred and the desulfurization performance test was stopped. The breakthrough sulfur capacity was calculated according to the following formula:

[0125] W=V×C 硫化氢 ×32.06÷[22.41×(100-C 硫化氢 )×m]×100

[0126] In the above formula:

[0127] C 硫化氢 —Volume fraction of hydrogen sulfide gas in hydrogen sulfide standard gas, unit: %

[0128] V—the volume value of hydrogen sulfide standard gas passing through, in L;

[0129] 32.06—Molar mass of sulfur, g / mol;

[0130] m—mass of the iron oxyhydroxide desulfurization catalyst sample, unit: g;

[0131] 22.41—The numerical value of the molar volume of an ideal gas under standard conditions, in L / mol;

[0132] The test results are shown in Table 1:

[0133] Table 1

[0134] From the test data in Table 1, it can be seen that the sulfur penetration capacity of Examples 1-6 is all above 40%, which shows that the iron oxyhydroxide desulfurization catalyst prepared by using the titanium dioxide by-product green vitriol of the present invention has a very high sulfur penetration capacity; in Comparative Example 1, the composite precipitant is replaced with ammonia water, and the sulfur penetration capacity of Comparative Example 1 is reduced to 24.7%, which shows that the composite precipitant can better provide a more stable pH fluctuation range than ammonia water, which can be more conducive to the rapid formation of precipitates by iron ions, making the particle size of the precipitate smaller, which will be beneficial to obtaining iron oxyhydroxide with a large specific surface area and good catalytic performance in the subsequent oxidation process; in Comparative Example 2, no peroxide is added, and the sulfur penetration capacity of Comparative Example 2 is reduced to 24.7%. It drops to 22.4%, which indicates that peroxide can effectively promote the oxidation of alkaline precipitates and promote the rapid formation of ferric oxyhydroxide, thereby obtaining ferric oxyhydroxide with a larger specific surface area and higher catalytic activity; in Comparative Example 3, no active promoter is added, and the sulfur penetration capacity of Comparative Example 3 drops to 26.9%, which indicates that the active promoter can greatly improve the catalytic activity of ferric oxyhydroxide. The active promoter, i.e., copper bismuthate or sodium bismuthate, may form a composite oxide with ferric oxyhydroxide during the drying process. This composite oxide has a certain effect on improving the ability of ferric oxyhydroxide to bind sulfur elements, thereby improving the desulfurization reaction activity and ultimately increasing the sulfur penetration capacity of the ferric oxyhydroxide desulfurizer.

[0135] Attachment Figure 1 and attached Figure 2 The following are scanning electron microscope photos of the iron oxyhydroxide obtained in step 1 of Example 1, magnified 10,000 times and 50,000 times respectively. Figure 1 and attached Figure 2 It can be seen that the iron oxyhydroxide is in the form of thin strips with a thickness at the nanometer level and a length basically at the micrometer level. This shows that the iron oxyhydroxide obtained by the present invention has the size of a nanomaterial in a certain dimension, so the specific surface area is very large, so it exhibits very excellent desulfurization performance.

[0136] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing an iron oxyhydroxide desulfurization catalyst prepared from a titanium dioxide byproduct, green vitriol, characterized in that: The method for preparing the iron oxyhydroxide desulfurization catalyst using the titanium dioxide byproduct green vitriol comprises two steps: preparing the iron oxyhydroxide and preparing the iron oxyhydroxide desulfurization catalyst; The method for preparing ferric oxyhydroxide comprises placing a titanium dioxide byproduct, green vitriol, and deionized water into a reaction kettle, stirring and dissolving the mixture under nitrogen protection, adding a composite precipitant dropwise after complete dissolution, controlling the pH of the solution in the kettle to be between 6 and 7.8, adding a peroxide after the addition of the composite precipitant, switching the nitrogen atmosphere to air, continuously introducing air and stirring to carry out an oxidation reaction, stopping the introduction of air and stirring when the color of the solution in the kettle no longer changes, filtering the discharged material, and washing and drying the filtrate to obtain ferric oxyhydroxide. The composite precipitant is obtained by mixing and dissolving a diamine substance, a quaternary ammonium base and deionized water; The preparation of the iron oxyhydroxide desulfurization catalyst comprises placing the iron oxyhydroxide, an active accelerator, calcium bentonite, sodium carboxymethyl cellulose, and deionized water into a double planetary mixer, stirring and dispersing the mixture into a paste, transferring the mixture into an extruder, extruding elongated particles, and drying the mixture to obtain a strip-shaped iron oxyhydroxide desulfurization catalyst; The active promoter is one of copper bismuthate and sodium bismuthate, or a mixture of the two in any mass ratio.

2. The method for preparing an iron oxyhydroxide desulfurization catalyst prepared from a titanium dioxide byproduct, green vitriol, according to claim 1, characterized in that: The diamine substance is ethylenediamine; The quaternary ammonium base is one of tetramethylammonium hydroxide, tetraethylammonium hydroxide, hexamethonium hydroxide, tetrabutylammonium hydroxide, and tetrapropylammonium hydroxide, or a mixture of any two or more of the above in any mass ratio; The peroxide is one of calcium peroxide, magnesium peroxide, potassium peroxide, sodium peroxide, and zinc peroxide, or a mixture of any two or more of them in any mass ratio.

3. The method for preparing an iron oxyhydroxide desulfurization catalyst prepared by using green vitriol, a by-product of titanium dioxide, according to claim 1, characterized in that: The mass ratio of the diamine substance, quaternary ammonium base and deionized water is 7-19:5-30:90-250; The mass ratio of the titanium dioxide byproduct green vitriol, deionized water, composite precipitant and peroxide is 50-120:160-390:25-80:1-6.

4. The method for preparing an iron oxyhydroxide desulfurization catalyst prepared by using green vitriol, a by-product of titanium dioxide, according to claim 1, characterized in that: The mass ratio of the ferric oxyhydroxide, the active accelerator, calcium bentonite, sodium carboxymethyl cellulose and deionized water is 40-90:5-13:90-240:4-10:25-50.

5. The method for preparing a desulfurization catalyst using green vitriol, a by-product of titanium dioxide, according to claim 1, wherein: The stirring and dispersing process has a stirring rate of 100 to 150 rpm and a dispersion rate of 5000 to 9000 rpm; The elongated particles have a cross-sectional diameter of 2 to 6 mm and a length of 8 to 20 mm; In the step of preparing the iron oxyhydroxide desulfurization catalyst, the drying temperature is 50-65° C. and the drying time is 25-44 hours.

6. The iron oxyhydroxide desulfurization catalyst prepared by the preparation method according to any one of claims 1 to 5 using the titanium dioxide by-product green vitriol, characterized in that: The iron oxyhydroxide desulfurization catalyst prepared by using the titanium dioxide byproduct green vitriol has a breakthrough sulfur capacity of 40.1-43.4%.

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