Vanadium tungstate-based interface catalyst and application thereof in catalytic oxidation desulfurization of slurry oil
By combining the vanadium-tungstate-based interface catalyst with hydrogen peroxide, the oil-water emulsion is formed using heptane viscosity-reducing agent, which solves the problem of efficient and low-cost desulfurization of thiophene-based sulfides in catalytic cracked oil slurry, and achieves efficient desulfurization under mild conditions and environmentally friendly reuse of solvents.
Patent Information
- Application Number
- CN202510366672.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-26
- Publication Date
- 2025-08-12
AI Technical Summary
The prior art is difficult to remove sulfides, especially thiophene sulfides in catalytic cracked oil slurry at high efficiency and low cost. Traditional hydrodesulfurization technology requires harsh conditions and the high viscosity of the oil slurry leads to difficulty in mass transfer.
The vanadium-tungstenic acid-based interface catalyst is combined with hydrogen peroxide, and the oil-water emulsion is formed by using heptane as a solvent to reduce viscosity. The mixture of vanadium-tungstenic acid and ionic liquid is used as a catalyst to increase the oil-water contact interface reaction efficiency.
It achieves efficient desulfurization under mild conditions, reduces production costs, improves the reaction efficiency of oil-water contact interface, and can be recycled and reused to avoid pollution.
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of catalytic oxidation desulfurization, in particular to a vanadium tungstate acid-based interfacial catalyst and its application in catalytic oxidation desulfurization of slurry oil. Background Art
[0002] As light oil is mined and utilized, crude oil reserves are in short supply and the degree of heavy and inferior quality is increasing. At present, the refining industry is in a critical period of high-quality development. Exploring high-value utilization solutions for the conversion of catalytic cracking slurry into specialty products is of great significance for promoting transformation and development, improving economic benefits and reducing emissions. Catalytic cracking slurry contains rich 3-5 ring aromatic hydrocarbon components, which are ideal raw materials for the preparation of high-quality needle coke. However, the application end requires that the sulfur content of needle coke should be controlled below 0.5 wt.% (5000 ppm). A higher sulfur content will generate hydrogen sulfide gas overflow during the high-temperature coke production process, causing crystal expansion and damage to the needle coke structure, which will seriously affect the anisotropy and thus the strength and conductivity of the graphite electrode.
[0003] The sulfur content in slurry oil typically ranges from 1 to 3 wt.%, with the primary sulfides being benzonaphthothiophene and its derivatives. Traditional hydrodesulfurization techniques require harsher reaction conditions (>420°C, >4.0 MPa) to remove these condensed-ring sulfides, breaking the C-S bonds. This high sulfur content leads to higher hydrogen consumption. However, thiophene sulfides are particularly susceptible to oxidation removal because, atomically, sulfur atoms have five more 3d orbitals than oxygen atoms, making them more susceptible to oxygen oxidation. Therefore, when the oxidant reacts with the sulfide, one or two oxygen atoms attach to the sulfur atom in the thiophene sulfide, increasing its dipole moment and polarity. These compounds are less soluble in non-polar solvents, effectively removing them from the oil phase.
[0004] Previous studies have reported on the oxidative desulfurization of model sulfides of gasoline and diesel, such as benzothiophene and dibenzothiophene, which can achieve gentle and efficient sulfide conversion and removal at room temperature and pressure. However, there are almost no oxidative applications and articles reported on oil slurry desulfurization, which represents a research gap. Hydrogen peroxide, as a green and inexpensive common oxidant, is being considered for use in oil slurry desulfurization systems. The first issue to be overcome in the design of the catalytic system is the mass transfer problem. First, the high viscosity of the oil slurry itself. It is proposed to use normal alkanes as solvents to reduce the viscosity of the solvent. The solvent selection is based on the following principles: 1. A non-polar solvent with a large difference in polarity from the sulfone oxidation products to facilitate the separation of the oxidation products; 2. A boiling point that is not too high to facilitate the subsequent recovery and recycling of the solvent; 3. The solvent itself is not easily oxidized; 4. It does not dissolve asphalt and colloids. Secondly, the introduction of an aqueous oxidant improves the mass transfer between the oil and water phases. The Gibbs free function of the surface of a dispersed system formed by the oscillation and stirring of two immiscible liquids, water and oil, is very high. Therefore, to form a stable emulsion and increase the oil-water contact interface, the Gibbs free function of the mixed system must be reduced. A common method for this is to add surfactants. Currently, there is an urgent need for a novel method for preparing an interfacial catalyst and its application in catalytic oxidation desulfurization for viscosity reduction of slurry oils. Summary of the Invention
[0005] In order to solve the above technical problems, the present invention provides a vanadium tungstate acid-based interfacial catalyst and its application in catalytic oxidation desulfurization of slurry viscosity reduction.
[0006] In a first aspect, the present invention provides an application of a vanadium tungstic acid-based interfacial catalyst in the catalytic oxidation desulfurization of slurry oil, wherein the preparation method of the vanadium tungstic acid-based interfacial catalyst comprises: mixing and stirring an aqueous solution of vanadium tungstic acid and an aqueous solution of an ionic liquid, and performing post-treatment; wherein the ionic liquid is a quaternary ammonium salt-type ionic liquid or an imidazole-type ionic liquid. The vanadium tungstic acid-based interfacial catalyst prepared by the present invention and its application are for the catalytic oxidation desulfurization of high-viscosity slurry oil, and a method of using heptane as a solvent for viscosity reduction catalysis is proposed. The vanadium tungstic acid-based interfacial catalyst of the present invention has the advantages of a simple preparation method, being green and environmentally friendly, increasing the oil-water contact interface reaction efficiency when used for slurry oxidation desulfurization, simple operation, and mild conditions.
[0007] Preferably, the method comprises mixing the viscosity-reduced slurry, the oxidant and the vanadium tungstate acid-based interfacial catalyst to carry out a desulfurization reaction; and optionally, evaporating the solvent in the oil phase to dryness and measuring the sulfur content.
[0008] Preferably, the viscosity reduction is carried out by diluting with a non-polar solvent, wherein the non-polar solvent is a normal alkane with a carbon number of 7 to 14.
[0009] Preferably, the non-polar solvent is a 7-10 normal alkane, preferably n-heptane, n-octane, n-nonane or n-decane.
[0010] Preferably, the oxidant comprises one or more of hydrogen peroxide, cumene hydroperoxide and ozone.
[0011] More preferably, the molar ratio of the oxidant to the sulfur element in the viscosity-reducing slurry (oxygen-sulfur ratio) is (2-10):1.
[0012] More preferably, the mass ratio of the vanadium tungstate-based interfacial catalyst to the viscosity-reducing slurry is 1:(40-800).
[0013] Preferably, the desulfurization reaction time is 0.5 to 3 h.
[0014] Preferably, the stirring rate of the desulfurization reaction is 200-1000 rpm.
[0015] More preferably, the temperature of the desulfurization reaction is 30-80°C.
[0016] In a second aspect, the present invention also provides a method for preparing the vanadium tungstic acid-type interfacial catalyst in the above-mentioned application, comprising: mixing and stirring an aqueous solution of vanadium tungstic acid and an aqueous solution of an ionic liquid, and performing post-treatment; the ionic liquid is a quaternary ammonium salt-type ionic liquid or an imidazole-type ionic liquid; and the molar ratio of the vanadium tungstic acid to the ionic liquid is 1:(1~8).
[0017] Preferably, the molar ratio of the vanadotungstic acid to the ionic liquid is 1:(2-8), for example, 1:(2, 3, 4, 5, 6, 7, etc.).
[0018] Preferably, the length of the monoalkyl chain of the ionic liquid is any even number between 8 and 18.
[0019] More preferably, the ionic liquid is selected from one or more of hexadecyltrimethylammonium chloride, dioctyldimethylammonium chloride, didodecyldimethylammonium chloride, didodecyldimethylimidazolium chloride, and dioctadecyldimethylammonium chloride. The vanadium tungstate-based interfacial catalyst obtained by the specific components and proportions employed in the present invention has a more favorable application effect.
[0020] Preferably, the post-treatment includes filtration and drying.
[0021] Further preferably, vanadium tungstic acid and ionic liquid are respectively dissolved in deionized water to obtain an aqueous solution of vanadium tungstic acid and an aqueous solution of ionic liquid; the aqueous solution of vanadium tungstic acid is added dropwise to the aqueous solution of ionic liquid under stirring at room temperature, filtered and rinsed with deionized water, and dried.
[0022] More preferably, the stirring time is 2 to 24 hours; and the drying is vacuum drying at 60 to 70°C for 10 to 12 hours.
[0023] More preferably, the concentration of the vanadotungstic acid aqueous solution is 0.015-0.080 mol / L, and the concentration of the ionic liquid aqueous solution is 0.00625-0.0188 mol / L.
[0024] In some embodiments of the present invention, vanadium tungstic acid and a quaternary ammonium salt or imidazole ionic liquid are respectively dissolved in water, and the vanadium tungstic acid aqueous solution is added dropwise to the aqueous solution of the ionic liquid, stirred at room temperature for 2-24 hours, filtered and rinsed with deionized water several times, and vacuum dried at 60°C for 12 hours.
[0025] The present invention combines the highly efficient catalytically active components of specific polyoxometalates with specific long-chain ionic liquids. Unlike traditional molecular emulsifiers, these materials, acting as emulsion stabilizers, remain in a moist, solid state within the emulsion. This stabilizer can be easily precipitated and recovered using simple physical methods. Furthermore, by selecting the appropriate cations and optimizing the conditions, desulfurization is achieved while simultaneously reducing aromatic oxidation, resulting in an excellent overall effect.
[0026] In a third aspect, the present invention further provides a vanadium tungstic acid type interface catalyst, which is prepared by the preparation method of the vanadium tungstic acid type interface catalyst.
[0027] The present invention has at least the following beneficial effects: the vanadotungstate-based interfacial catalyst provided by the present invention has a simple synthesis strategy and high atomic utilization rate. The oxidative desulfurization process of the present invention has high catalytic efficiency, mild reaction conditions, reduced production costs, and enhanced safety. The viscosity reduction catalytic method described in the present invention facilitates mass transfer during the reaction, and the viscosity reduction solvent can be recycled and reused, avoiding environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0029] Figure 1 This is a trend diagram of the viscosity of the oil slurry before and after viscosity reduction versus reaction temperature.
[0030] Figure 2 This is a diagram showing the desulfurization effects of different catalysts preferred in the present invention.
[0031] Figure 3 The catalyst DDA-VW of the present invention 12 Desulfurization effect diagram under different qualities.
[0032] Figure 4The catalyst DDA-VW of the present invention 12 Desulfurization effect diagram under different oxygen-sulfur ratios.
[0033] Figure 5 The catalyst DDA-VW of the present invention 12 Infrared spectra of each component.
[0034] Figure 6 The catalyst DDA-VW of the present invention 12 Scanning electron microscope image of .
[0035] Figure 7 The catalyst DDA-VW of the present invention 12 Infrared spectra before and after desulfurization.
[0036] Figure 8 The catalyst DDA-VW of the present invention 12 Photograph of a stable oil-water interface.
[0037] Figure 9 The catalyst DDA-VW of the present invention 12 Single component performance comparison bar chart. DETAILED DESCRIPTION
[0038] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0039] The endpoints of the ranges and any values disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values can be combined with each other to form one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed in the present invention.
[0040] Where specific techniques or conditions are not specified in the examples of the present invention, the techniques or conditions described in the literature in the field or in the product specifications were followed. All devices, instruments, reagents, etc. used, where the manufacturer is not specified, are conventional products available through regular channels. All experimental reagents and raw materials involved are commercially available, and all reagents are analytically pure.
[0041] In the following examples, vanadotungstic acid was obtained using the method described in ACS Sustainable Chem. Eng. 2022, 10, 11533−11543; didodecyldimethylammonium chloride (DDAC) and other materials were commercially available. The oil compositions used were as follows: Five model oils with a sulfur content of 1000 mg / L were prepared by dissolving benzonaphthothiophene (BNT), 4-methyldibenzothiophene (4-MDBT), 4,6-dimethyldibenzothiophene (4,6-DMDBT), dibenzothiophene (DBT), or benzothiophene (BT) in dodecane.
[0042] The total sulfur and total nitrogen element analyzer (multi EA 5100) is used to detect the changes in the sulfide content in the oil and calculate the desulfurization rate: in, % is the desulfurization rate, C0 is the initial sulfur content, C t It is the sulfur content measured by sampling at t minutes into the reaction.
[0043] Example 1 This embodiment provides a vanadium tungstate-based interface catalyst, the preparation method of which comprises: weighing 0.2575 g of vanadium tungstate (K4[VW 12 ]·21H2O, abbreviated as VW 12 ) was dissolved in 1 ml of water. 0.157 g of didodecyl dimethyl ammonium chloride (DDAC) was weighed and dissolved in 20 ml of water. The vanadium tungstate aqueous solution was added dropwise to the DDAC aqueous solution under magnetic stirring. The mixture was stirred at room temperature for 2 h, filtered and rinsed with deionized water several times, and dried under vacuum at 60°C for 12 h. The product was named DDA-VW. 12 .
[0044] Example 2 This embodiment provides a type of vanadium tungstate-based interfacial catalyst, the preparation method of which is the same as that of Example 1, except that didodecyldimethylammonium chloride (DDAC) is replaced by dioctyldimethylammonium chloride (BDAC), hexadecyltrimethylammonium chloride (CTAC), didodecyldimethylimidazolium chloride (DmimC) and dioctadecyldimethylammonium chloride (DOAC). They are named BDA-VW 12 、CTA-VW 12 、Dmim-VW 12 and DOA-VW 12 .
[0045] Example 3 This example provides a method for reducing the viscosity of slurry oil. The treatment method is to take 25 g of slurry oil and dissolve it in 75 ml of n-heptane by ultrasonication until it is uniformly dissolved. The sulfur content is measured to be 4300 mg / L. The viscosity is reduced from the original 2447 mPa.s to 2.12 mPa.s. The viscosity changes with temperature as shown in the following figure: Figure 1 shown.
[0046] Example 4 This example provides an application of a vanadium tungstate-based interfacial catalyst in the catalytic oxidation desulfurization of a model slurry, comprising: taking 20 mg of the catalyst (DDA-VW 12 、BDA-VW 12 、CTA-VW 12 、Dmim-VW 12 and DOA-VW 12 ) were added to 8 mL gas phase analysis bottles with rubber gaskets. 5 mL of BNT model oil with a sulfur content of 1000 mg / L was added and stirred in a parallel block at 60°C for 5 minutes. This was the heating stage. Subsequently, 64 μL of hydrogen peroxide (30 wt%) was added at an oxygen-sulfur molar ratio of 4. The timer was started and the upper oil phase was sampled at fixed 20-minute intervals through a filter head for total sulfur analysis. The performance results are shown in Figure 1. Figure 2 shown.
[0047] Example 5 This embodiment provides the application of vanadium tungstate-based interfacial catalyst in catalytic oxidation desulfurization of model slurry, including: taking 20 mg of DDA-VW 12 The reaction was then added to an 8 mL gas phase analysis vial with a rubber gasket, along with 5 mL of BNT model oil with a sulfur content of 1000 mg / L. The mixture was stirred in a parallel block at 50°C for 5 minutes (this is the heating phase). Subsequently, 48 μL of hydrogen peroxide (30 wt%) was added at an oxygen-sulfur molar ratio of 3, and the timer was started. After a 2-hour reaction, the upper oil phase was sampled and filtered through a filter for total sulfur analysis, revealing a desulfurization rate of 81.2%.
[0048] Example 6 This embodiment provides the application of vanadium tungstate-based interfacial catalyst in catalytic oxidation desulfurization of model slurry, including: taking 20 mg of DDA-VW 12 The reaction was then added to an 8 mL gas phase analysis vial with a rubber gasket, along with 5 mL of BNT model oil with a sulfur content of 1000 mg / L. The mixture was stirred in a parallel block at 60°C for 5 minutes (this is the heating phase). Subsequently, 48 μL of hydrogen peroxide (30 wt%) was added at an oxygen-sulfur molar ratio of 3, and the timer was started. After a 2-hour reaction, the upper oil phase was sampled and filtered through a filter for total sulfur analysis, revealing a desulfurization rate of 98.1%.
[0049] Example 7 This embodiment provides the application of vanadium tungstate-based interfacial catalyst in catalytic oxidation desulfurization of slurry viscosity reduction, including: taking 5 mg of DDA-VW 12 Add to an 8 mL gas phase analysis bottle with a rubber gasket, add 5 mL of BNT model oil with a sulfur content of 1000 mg / L, and stir in a parallel block at 60°C for 5 minutes. This is the heating stage. Then, add 48 μL of hydrogen peroxide (30 wt%) at an oxygen-sulfur molar ratio of 3, start the timer, and take samples of the upper oil phase at fixed 20-minute intervals through a filter head for total sulfur analysis. Performance results are shown as follows: Figure 3 shown.
[0050] Example 8 This embodiment provides the application of vanadium tungstate-based interfacial catalyst in catalytic oxidation desulfurization of model slurry, including: taking 10 mg of DDA-VW 12 Add to an 8 mL gas phase analysis bottle with a rubber gasket, add 5 mL of BNT model oil with a sulfur content of 1000 mg / L, and stir in a parallel block at 60°C for 5 minutes. This is the heating stage. Then, add 48 μL of hydrogen peroxide (30 wt%) at an oxygen-sulfur molar ratio of 3, start the timer, and take samples of the upper oil phase at fixed 20-minute intervals through a filter head for total sulfur analysis. Performance results are shown as follows: Figure 3 shown.
[0051] Example 9 This embodiment provides the application of vanadium tungstate-based interfacial catalyst in catalytic oxidation desulfurization of model oil slurry, comprising: taking 30 mg of DDA-VW 12 Add to an 8 mL gas phase analysis bottle with a rubber gasket, add 5 mL of BNT model oil with a sulfur content of 1000 mg / L, and stir in a parallel block at 60°C for 5 minutes. This is the heating stage. Then, add 48 μL of hydrogen peroxide (30 wt%) at an oxygen-sulfur molar ratio of 3, start the timer, and take samples of the upper oil phase at fixed 20-minute intervals through a filter head for total sulfur analysis. Performance results are shown as follows: Figure 3 shown.
[0052] Example 10 This embodiment provides the application of vanadium tungstate-based interfacial catalyst in catalytic oxidation desulfurization of model slurry, including: taking 20 mg of DDA-VW 12 Add to an 8 mL gas phase analysis bottle with a rubber gasket, add 5 mL of BNT model oil with a sulfur content of 1000 mg / L, and stir in a parallel block at 60°C for 5 minutes. This is the heating stage. Then, add 32 μL of hydrogen peroxide (30 wt%) at an oxygen-sulfur molar ratio of 2 and start the timer. Samples of the upper oil phase are taken at fixed 20-minute intervals and filtered through a filter head for total sulfur analysis. Performance results are shown as follows: Figure 4shown.
[0053] Example 11 This embodiment provides the application of vanadium tungstate-based interfacial catalyst in catalytic oxidation desulfurization of model slurry, including: taking 20 mg of DDA-VW 12 Add to an 8 mL gas phase analysis bottle with a rubber gasket, add 5 mL of BNT model oil with a sulfur content of 1000 mg / L, and stir in a parallel block at 60°C for 5 minutes. This is the heating stage. Then, add 80 μL of hydrogen peroxide (30 wt%) at an oxygen-sulfur molar ratio of 5 and start the timer. Samples of the upper oil phase are taken at fixed 20-minute intervals and filtered through a filter head for total sulfur analysis. Performance results are shown in Figure 1. Figure 4 shown.
[0054] Example 12 This embodiment provides the application of vanadium tungstate-based interfacial catalyst in catalytic oxidation desulfurization of model slurry, including: taking 20 mg of DDA-VW 12 The reaction mixture was added to an 8 mL gas phase analysis vial with a rubber gasket, along with 5 mL of DBT model oil with a sulfur content of 1000 mg / L. The mixture was stirred in a parallel block at 60°C for 5 minutes (this is the heating phase). Subsequently, 48 μL of hydrogen peroxide (30 wt%) was added at an oxygen-sulfur molar ratio of 3, and the timer was started. After a 2-hour reaction, the upper oil phase was sampled and filtered through a filter for total sulfur analysis, revealing a desulfurization rate of 95.9%.
[0055] Example 13 This embodiment provides the application of vanadium tungstate-based interfacial catalyst in catalytic oxidation desulfurization of model slurry, including: taking 20 mg of DDA-VW 12 The reaction mixture was added to an 8 mL gas phase analysis vial with a rubber gasket, along with 5 mL of 4-MDBT model oil with a sulfur content of 1000 mg / L. The mixture was stirred in a parallel block at 60°C for 5 minutes (this is the heating phase). Subsequently, 48 μL of hydrogen peroxide (30 wt%) was added at an oxygen-sulfur molar ratio of 3, and the timer was started. After a 2-hour reaction, the upper oil phase was sampled and filtered through a filter for total sulfur analysis, revealing a desulfurization rate of 93.0%.
[0056] Example 14 This embodiment provides the application of vanadium tungstate-based interfacial catalyst in catalytic oxidation desulfurization of model slurry, including: taking 20 mg of DDA-VW 12The reaction mixture was added to an 8 mL gas phase analysis vial with a rubber gasket, along with 5 mL of 4,6-DMDBT model oil with a sulfur content of 1000 mg / L. The mixture was stirred in a parallel block at 60°C for 5 minutes (this is the heating phase). Subsequently, 48 μL of hydrogen peroxide (30 wt%) was added at an oxygen-sulfur molar ratio of 3, and the timer was started. After a 2-hour reaction, the upper oil phase was sampled and filtered through a filter for total sulfur analysis, revealing a desulfurization rate of 89.1%.
[0057] Example 15 This embodiment provides the application of vanadium tungstate-based interfacial catalyst in catalytic oxidation desulfurization of model slurry, including: taking 20 mg of DDA-VW 12 The reaction mixture was added to an 8 mL gas phase analysis vial with a rubber gasket, along with 5 mL of BT model oil with a sulfur content of 1000 mg / L. The mixture was stirred in a parallel block at 60°C for 5 minutes (this is the heating stage). Subsequently, 48 μL of hydrogen peroxide (30 wt%) was added at an oxygen-sulfur molar ratio of 3, and the timer was started. After a 2-hour reaction, the upper oil phase was sampled and filtered through a filter for total sulfur analysis, revealing a desulfurization rate of 74.9%.
[0058] Example 16 This embodiment provides the application of vanadium tungstate-based interfacial catalyst in catalytic oxidation desulfurization of slurry viscosity reduction, comprising: taking 14.39 mg of DDA-VW 12 The mixture was added to an 8 mL gas phase analysis vial with a rubber gasket, followed by 5 mL of heptane viscosity-reduced oil slurry with a sulfur content of 4300 mg / L. The mixture was stirred in a parallel block at 64°C for 5 minutes (this is the heating phase). Subsequently, 253 μL of hydrogen peroxide (30 wt%) was added at an oxygen-sulfur molar ratio of 3.69, and the timer was started. After 152 minutes of reaction, a sample of the upper oil phase was filtered through a filter and analyzed for total sulfur, revealing a sulfur content of 3181 ppm.
[0059] Example 17 This embodiment provides the application of a vanadium tungstate acid-based interfacial catalyst in catalytic oxidation desulfurization of slurry viscosity reduction, including: Take 20.62 mg of DDA-VW 12 The mixture was added to an 8 mL gas phase analysis vial with a rubber gasket, followed by 5 mL of heptane viscosity-reduced oil slurry with a sulfur content of 4300 mg / L. The mixture was stirred in a parallel block at 31°C for 5 minutes (this is the heating phase). Subsequently, 257 μL of hydrogen peroxide (30 wt%) was added at an oxygen-sulfur molar ratio of 3.75, and the timer was started. After a 2-hour reaction, a sample of the upper oil phase was filtered through a filter and analyzed for total sulfur, revealing a sulfur content of 3896 ppm.
[0060] Comparative Example 1 This comparative example provides VW 12Applications in catalytic oxidation desulfurization of model slurry oil include: Take 20 mg of VW 12 The reaction was then added to an 8 mL gas phase analysis vial with a rubber gasket, along with 5 mL of BNT model oil with a sulfur content of 1000 mg / L. The mixture was stirred in a parallel block at 60°C for 5 minutes (this is the heating phase). Subsequently, 48 μL of hydrogen peroxide (30 wt%) was added at an oxygen-sulfur molar ratio of 3, and the timer was started. After a 2-hour reaction, the upper oil phase was sampled and filtered through a filter for total sulfur analysis, revealing a desulfurization rate of 8.5%.
[0061] Comparative Example 2 This comparative example provides the application of DDAC in the catalytic oxidation desulfurization of model slurry oil, including: 20 mg of DDAC was added to an 8 mL gas phase analysis vial with a rubber gasket. 5 mL of BNT model oil with a sulfur content of 1000 mg / L was also added. The mixture was stirred in a parallel block at 60°C for 5 minutes (this is the heating phase). Then, 48 μL of hydrogen peroxide (30 wt%) was added at an oxygen-sulfur molar ratio of 3, and the timer was started. After 2 hours of reaction, the upper oil phase was sampled and filtered through a filter for total sulfur analysis. The desulfurization rate reached 6.8%.
[0062] The infrared spectrum of the catalyst in Example 1 is shown in Figure 5 2853 and 2924 cm -1 It is the absorption vibration peak of the methyl and methylene groups of the alkyl chain on the cation, ranging from 700 to 1100 cm -1 The characteristic absorption peak of vanadium tungstate unit appears in the range of , indicating the successful preparation of vanadium tungstate-based interface catalyst. Figure 6 As shown. The coral-like morphology formed by cross-linking long alkyl chains, the outer layer is an oily waxy layer. This type of material will easily break up into smaller particles in the oil phase, so that it has a better dispersion effect during the stirring process. The infrared spectrum of the catalyst before and after the desulfurization reaction in Example 6 is shown in FIG. Figure 7 The absorption peak of the catalyst before and after the desulfurization reaction has no obvious change, indicating that its structure is not destroyed and has good stability. Comparative Example 1 shows that there is no extraction agent or lipophilic component in this system, so VW 12 The lack of effective contact with the reaction substrate results in an unsatisfactory catalytic effect. Although the DDAC described in Comparative Example 2 can fully contact the substrate, there is no active component that can convert the substrate, so the desulfurization rate is low. The above examples all illustrate that when the two are combined, the long alkyl chain enhances the lipophilicity of the catalyst, and the catalyst can be evenly distributed throughout the oil phase to react, while also stabilizing a large amount of oil-water interface in the oil phase. Figure 8 , which increases the mass transfer effect and thus improves the catalytic performance ( Figure 9 ).
[0063] 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 it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.
Claims
1. Application of a vanadium tungstate acid-based interfacial catalyst in catalytic oxidation desulfurization of slurry oil, wherein: The preparation method of the vanadium tungstic acid type interface catalyst comprises: mixing and stirring an aqueous solution of vanadium tungstic acid and an aqueous solution of an ionic liquid, and performing post-treatment; the ionic liquid is a quaternary ammonium salt type ionic liquid or an imidazole type ionic liquid.
2. The use according to claim 1 or 2, characterized in that include: Mixing the reduced viscosity oil slurry, the oxidant and the vanadium tungstate acid-based interfacial catalyst to carry out a desulfurization reaction; And optionally, the solvent in the oil phase is evaporated to dryness and the sulfur content is determined.
3. The use according to claim 2, characterized in that The method comprises diluting and reducing the viscosity with a non-polar solvent, wherein the non-polar solvent is a normal alkane with a carbon number of 7 to 14; preferably, the non-polar solvent is a normal alkane with a carbon number of 7 to 10.
4. The use according to claim 3, characterized in that The molar ratio of the oxidant to the sulfur in the viscosity-reducing slurry is (2-10):1; the mass ratio of the vanadium tungstate-based interfacial catalyst to the viscosity-reducing slurry is 1:(40-800).
5. The use according to claim 4, characterized in that The temperature of the desulfurization reaction is 30-80°C.
6. The method for preparing the vanadium tungstate type interfacial catalyst for use in claims 1-5, characterized in that: include: The aqueous solution of vanadium tungstic acid and the aqueous solution of ionic liquid are mixed and stirred for post-treatment; the ionic liquid is a quaternary ammonium salt type ionic liquid or an imidazole type ionic liquid; the molar ratio of the vanadium tungstic acid to the ionic liquid is 1: (1-8).
7. The preparation method according to claim 6, characterized in that The length of the monoalkyl chain of the ionic liquid is any even number between 8 and 18.
8. The preparation method according to claim 7, characterized in that The ionic liquid is selected from one or more of hexadecyltrimethylammonium chloride, bisoctyldimethylammonium chloride, didodecyldimethylammonium chloride, didodecyldimethylimidazolium chloride and distearyldimethylammonium chloride.
9. The preparation method according to any one of claims 1 to 8, characterized in that The post-treatment includes filtration and drying. Preferably, vanadium tungstic acid and ionic liquid are respectively dissolved in deionized water to obtain an aqueous solution of vanadium tungstic acid and an aqueous solution of ionic liquid; the aqueous solution of vanadium tungstic acid is added dropwise to the aqueous solution of ionic liquid and stirred at room temperature, while filtration is performed while rinsing with deionized water, and drying is performed; the stirring time is 2 to 24 hours; and the drying is vacuum drying at 60 to 70°C for 10 to 12 hours.
10. A vanadium tungstate type interfacial catalyst, characterized in that: The vanadium tungstate interface catalyst is prepared by the preparation method of any one of claims 6 to 9.