Modified halloysite, oxidative desulfurization catalyst and preparation method and application of modified halloysite and oxidative desulfurization catalyst

Abstract

The invention discloses modified halloysite, an oxidative desulfurization catalyst and a preparation method and application thereof, and belongs to the technical field of oil product oxidative desulfurization. The preparation method of the modified halloysite comprises the following steps: S1, mixing and stirring halloysite, sodium tungstate and water to obtain an intermediate product W / HNT; s2, the intermediate product W / HNT, cyclohexane and hexadecyl trimethoxy silane are mixed and stirred, and the modified halloysite is obtained. In addition, the invention also provides an oxidative desulfurization catalyst which comprises the modified halloysite prepared by the preparation method or the modified halloysite. In addition, the invention also provides the modified halloysite prepared by the preparation method or application of the modified halloysite in oxidative desulfurization. The modified halloysite prepared by the preparation method provided by the invention realizes efficient oxidative desulfurization in fuel oil.

Description

Technical Field

[0001] The invention relates to the technical field of oil oxidation desulfurization, and in particular to a modified halloysite, an oxidation desulfurization catalyst, and a preparation method and application thereof. Background Art

[0002] As countries around the world are increasingly restricting the sulfur content in fuel, some places have even explicitly notified that the sulfur content should not exceed 10ppm. The transportation and power industries are still unable to stop using fuel, and in this case, they can only further obtain clean energy through fuel desulfurization.

[0003] At present, the main desulfurization methods at home and abroad are hydrodesulfurization and non-hydrodesulfurization technology. Hydrodesulfurization (HDS) is the most widely used industrial desulfurization technology. However, the reaction and operating conditions of this technology are harsh, and it will cause high energy consumption. Among non-hydrodesulfurization, oxidative desulfurization (ODS) can not only remove refractory sulfur-containing compounds without hydrogen consumption, but also obtain ultra-low sulfur fuel oil at a lower cost under mild conditions.

[0004] How to achieve oxidative desulfurization efficiently is a problem that needs to be solved by existing technologies. Summary of the invention

[0005] The purpose of the present invention is to overcome the above technical deficiencies, provide a modified halloysite, an oxidative desulfurization catalyst and a preparation method and application thereof, and solve the technical problem of how to efficiently achieve oxidative desulfurization in the prior art.

[0006] In order to achieve the above technical purpose, the technical solution of the present invention provides a method for preparing modified halloysite, comprising the following steps:

[0007] S1, mixing halloysite, sodium tungstate and water to obtain an intermediate product W / HNT;

[0008] S2. Mix and stir the intermediate product W / HNT, cyclohexane and hexadecyltrimethoxysilane to obtain modified halloysite.

[0009] In any embodiment, in step S1, the material ratio of the halloysite, the sodium tungstate and water is 1 g: (0.01-0.05) g: (10-15) mL.

[0010] In any embodiment, in step S1, the temperature of the mixing and stirring is 20-35° C., and the time of the mixing and stirring is 20-24 hours.

[0011] In any embodiment, in step S2, the material ratio of the intermediate product W / HNT, the cyclohexane and the hexadecyltrimethoxysilane is 1 g:(10-15) mL:(1-3) μL.

[0012] In any embodiment, in step S2, the temperature of the mixing and stirring is 20-35° C., and the time of the mixing and stirring is 20-24 hours.

[0013] In addition, the present invention also provides a modified halloysite prepared by the above preparation method.

[0014] In addition, the present invention also provides an oxidative desulfurization catalyst, comprising the modified halloysite prepared by the above-mentioned preparation method or the above-mentioned modified halloysite.

[0015] In addition, the present invention also proposes the use of the modified halloysite prepared by the above preparation method or the modified halloysite in the oxidative desulfurization of fuel oil.

[0016] In any embodiment, the application comprises: mixing fuel, an oxidant and the modified halloysite for reaction.

[0017] In any embodiment, the oxidant is a hydrogen peroxide solution with a volume concentration of 25%-35%; and / or, the temperature of the mixed reaction is 40-70°C; and / or, the volume ratio of the oxidant to the fuel is (0.005-0.0055):1; and / or, the dosage ratio of the modified halloysite to the fuel is (0.004-0.005) g:1 mL.

[0018] Compared with the prior art, the beneficial effects of the present invention include: mixing and stirring halloysite, sodium tungstate and water to obtain an intermediate product W / HNT; mixing and stirring the intermediate product W / HNT, cyclohexane and hexadecyltrimethoxysilane to obtain modified halloysite, halloysite (i.e., HNT) has Lewis acid sites, and tungsten oxide is electrostatically anchored and loaded in the internal cavity of HNT through the preparation method proposed by the present invention, and excellent catalytic performance is achieved with its low loading amount of tungsten oxide, and efficient oxidative desulfurization can be realized in fuel. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 are SEM images, TEM images and mapping images of the halloysite and modified halloysite in Example 1 of the present invention; wherein, Figure 1 (a) is the SEM image of halloysite; Figure 1 (b) is the SEM image of modified halloysite; Figure 1 (c) is the TEM image of halloysite; Figure 1 (d) is the TEM image of modified halloysite; Figure 1 (e) is the mapping diagram of modified halloysite.

[0020] Figure 2It is the result of the desulfurization rate of DBT by the modified halloysite prepared in Example 1 of the present invention and the sample of the comparative example. DETAILED DESCRIPTION

[0021] The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0022] If there is no special explanation, the "include" and "comprising" mentioned in this application are open-ended or closed-ended. For example, the "include" and "comprising" may mean that other components not listed may also be included or only the listed components may be included or only the listed components may be included.

[0023] If not specifically stated, in this application, the term "or" is inclusive. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0024] This specific embodiment provides a method for preparing modified halloysite, comprising the following steps:

[0025] S1. Mixing and stirring halloysite, sodium tungstate and water at 20-35° C. for 20-24 hours to obtain an intermediate product W / HNT; the material ratio of the halloysite, sodium tungstate and water is 1 g:(0.01-0.05) g:(10-15);

[0026] S2. Mix and stir the intermediate product W / HNT, cyclohexane and hexadecyltrimethoxysilane at 20-35° C. for 20-24 hours to obtain modified halloysite; the material ratio of the intermediate product W / HNT, the cyclohexane and the hexadecyltrimethoxysilane is 1 g: (10-15) mL: (1-3) μL.

[0027] This specific implementation also provides a modified halloysite, which is prepared by the above preparation method.

[0028] This specific embodiment also provides an oxidative desulfurization catalyst, including the modified halloysite prepared by the above preparation method or the above modified halloysite.

[0029] This specific embodiment also proposes the use of the modified halloysite prepared by the above preparation method or the modified halloysite in the oxidative desulfurization of fuel oil, including: mixing the fuel oil, the oxidant and the modified halloysite for reaction, wherein the oxidant is a hydrogen peroxide solution with a volume concentration of 25%-35%; the temperature of the mixing reaction is 40-70°C; the volume ratio of the oxidant to the fuel oil is (0.005-0.0055):1; the dosage ratio of the modified halloysite to the fuel oil is (0.004-0.005) g:1 mL.

[0030] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] In the present invention, reference is made to “some embodiments”, “this embodiment”, examples, etc., which describe a subset of all possible embodiments, but it can be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0032] If similar descriptions of "first / second" appear in the application documents, the following instructions are added. In the following description, the terms "first\second\third" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged in a specific order or sequence where permitted, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0033] In this embodiment, the term "and / or" is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, object A and / or object B may represent three situations: object A exists alone, object A and object B exist at the same time, and object B exists alone.

[0034] Hereinafter, the embodiments of the present application will be described. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. If no specific techniques or conditions are indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. If the manufacturer is not indicated in the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0035] Example 1

[0036] This embodiment provides a modified halloysite, which is prepared by the following steps:

[0037] S1, 1 g of halloysite (raw HNT), 0.01 g of sodium tungstate and 10 mL of water were mixed and stirred at 25° C. for 24 hours, and then washed and dried with deionized water to obtain a white powder intermediate product W / HNT;

[0038] S2. 1 g of the intermediate product W / HNT, 10 mL of cyclohexane and 1 μL of hexadecyltrimethoxysilane were mixed and stirred at 25° C. for 24 hours, and vacuum dried at 100° C. to obtain modified halloysite (ie, W / HNT / M).

[0039] Combination Figure 1 It can be seen that Figure 1 In (a), the raw HNT is a rod-shaped structure. Figure 1 (b) is the W / HNT / M catalyst after loading and modification. Its rod-shaped structural characteristics have not changed. Figure 1 (c) and Figure 1 (d) It can be seen that both raw HNT and W / HNT / M have hollow structures, and loading and modification do not destroy their unique structures. Figure 1 (e) It can be seen that W / HNT / M contains Si, O, Al and W elements.

[0040] The test using ICP (inductively coupled plasma emission spectrometer) showed that the loading amount of tungsten in the modified halloysite of this embodiment was 0.36%.

[0041] Example 2

[0042] This embodiment provides a modified halloysite, which is prepared by the following steps:

[0043] S1, 1 g of halloysite, 0.02 g of sodium tungstate and 15 mL of water were mixed and stirred at 35° C. for 20 hours, and then washed and dried with deionized water to obtain a white powder intermediate product W / HNT;

[0044] S2. 1 g of the intermediate product W / HNT, 15 mL of cyclohexane and 2 μL of hexadecyltrimethoxysilane were mixed and stirred at 35° C. for 20 hours, and vacuum dried at 100° C. to obtain modified halloysite.

[0045] The test using ICP (inductively coupled plasma emission spectrometer) showed that the loading amount of tungsten in the modified halloysite of this embodiment was 0.42%.

[0046] Example 3

[0047] This embodiment provides a modified halloysite, which is prepared by the following steps:

[0048] S1, 1 g of halloysite, 0.01 g of sodium tungstate and 12 mL of water were mixed and stirred at 20° C. for 22 hours, and then washed and dried with deionized water to obtain a white powder intermediate product W / HNT;

[0049] S2. 1 g of the intermediate product W / HNT, 12 mL of cyclohexane and 3 μL of hexadecyltrimethoxysilane were mixed and stirred at 20° C. for 22 hours, and vacuum dried at 100° C. to obtain modified halloysite.

[0050] The test using ICP (inductively coupled plasma emission spectrometer) showed that the loading amount of tungsten in the modified halloysite of this embodiment was 0.48%.

[0051] Example 4

[0052] This embodiment provides a modified halloysite, which is prepared by the following steps:

[0053] S1, 1 g of halloysite, 0.02 g of sodium tungstate and 10 mL of water were mixed and stirred at 30° C. for 24 hours, and then washed and dried with deionized water to obtain a white powder intermediate product W / HNT;

[0054] S2. 1 g of the intermediate product W / HNT, 10 mL of cyclohexane and 2 μL of hexadecyltrimethoxysilane were mixed and stirred at 30° C. for 24 hours, and vacuum dried at 100° C. to obtain modified halloysite.

[0055] The test using ICP (inductively coupled plasma emission spectrometer) showed that the loading amount of tungsten in the modified halloysite of this embodiment was 0.48%.

[0056] Related applications

[0057] Type of fuel used:

[0058] The model oil is prepared by adding thiophene, dibenzothiophene and 4,6-dimethyldibenzothiophene into n-octane to prepare a 500 ppm model oil.

[0059] Testing and calculation method of desulfurization rate:

[0060] In a round-bottom flask equipped with magnetic stirring, catalyst-modified halloysite is added to the model oil. After reaching the reaction temperature, an oxidant is added. The model oil is taken out at regular intervals, and then the sulfur content in the oil is detected by gas chromatography (GC-FID). The desulfurization rate is calculated:

[0061]

[0062] Configure simulated sulfur fuel:

[0063] 1 g of dibenzothiophene (DBT) and 0.7 g of tetradecane were added to 500 mL of n-octane and ultrasonicated for 30 min to prepare a 500 ppm simulated sulfur-containing fuel.

[0064] 0.046 g of 4,6-dimethyldibenzothiophene (4,6-DMDBT) and 0.0367 mL of tetradecane were added to 20 mL of n-octane and ultrasonicated for 30 min to prepare a 500 ppm simulated sulfur-containing fuel.

[0065] 0.0184 g of thiophene (BT) and 0.0367 mL of tetradecane were added to 20 mL of n-octane and ultrasonicated for 30 min to prepare a 500 ppm simulated sulfur-containing fuel.

[0066] The volume concentration of H2O2 in the following application examples is 30%. The modified halloysite prepared in Example 1 is used as a catalyst in the following application examples.

[0067] Application Example 1

[0068] The model oil (DBT) was heated to 40°C and maintained for 20 minutes, then 0.06 g of catalyst and 55 μL of H2O2 were added and reacted for 120 minutes. The sulfur content was measured and the desulfurization rate was calculated to be 76.7%.

[0069] Application Example 2

[0070] The model oil (DBT) was heated to 50°C and maintained for 20 minutes, then 0.06 g of catalyst and 55 μL of H2O2 were added and reacted for 120 minutes. The sulfur content was measured and the desulfurization rate was calculated to be 78.95%.

[0071] Application Example 3

[0072] The model oil (DBT) was heated to 60°C and maintained for 20 minutes, then 0.06 g of catalyst and 55 μL of H2O2 were added, and the reaction was carried out for 90 minutes. The sulfur content was measured and the desulfurization rate was calculated to be 100%.

[0073] Application Example 4

[0074] The model oil (DBT) was heated to 70°C and maintained for 20 minutes, then 0.06 g of catalyst and 55 μL of H2O2 were added and reacted for 60 minutes. The sulfur content was measured and the desulfurization rate was calculated to be 100%.

[0075] Application Example 5

[0076] The simulated oil (DBT) was heated to 60°C and maintained for 20 minutes, then 0.06 g of catalyst and 33 μL of H2O2 were added and reacted for 120 minutes. The sulfur content was measured and the desulfurization rate was calculated to be 88.68%.

[0077] Application Example 6

[0078] The simulated oil (DBT) was heated to 60°C and maintained for 20 minutes, and then 0.06 g of catalyst and 44 μL of H2O2 were added. The reaction was carried out for 120 minutes, and the sulfur content was measured and the desulfurization rate was calculated to be 100%.

[0079] Application Example 7

[0080] The simulated oil (DBT) was heated to 60°C and maintained for 20 minutes, and then 0.06 g of catalyst and 55 μL of H2O2 were added. The reaction was carried out for 75 minutes, and the sulfur content was measured and the desulfurization rate was calculated to be 100%.

[0081] Application Example 8

[0082] The simulated oil (DBT) was heated to 60°C and maintained for 20 minutes, and then 0.06 g of catalyst and 66 μL of H2O2 were added. The reaction was carried out for 90 minutes, and the sulfur content was measured and the desulfurization rate was calculated to be 100%.

[0083] Application Example 9

[0084] The simulated oil (DBT) was heated to 60°C and maintained for 20 minutes, then 0.06 g of catalyst and 77 μL of H2O2 were added and reacted for 90 minutes. The sulfur content was measured and the desulfurization rate was calculated to be 100%.

[0085] Application Example 10

[0086] The simulated oil (BT) was heated to 60°C and maintained for 20 minutes, then 0.06 g of catalyst and 55 μL of H2O2 were added and reacted for 120 minutes. The sulfur content was measured and the desulfurization rate was calculated to be 77.2%.

[0087] Application Example 11

[0088] The simulated oil (4,6-DMDBT) was heated to 60°C and maintained for 20 minutes, then 0.06 g of catalyst and 55 μL of H2O2 were added and reacted for 120 minutes. The sulfur content was measured and the desulfurization rate was calculated to be 90.01%.

[0089] Table 1 Test results of application examples 1-11

[0090]

[0091]

[0092] As can be seen from Table 1, the best reaction temperature selected from Application Examples 1, 2, 3, and 4 is 60°C. The best oxidant dosage required for the reaction selected from Application Examples 5, 6, 7, 8, and 9 is 55 μL, that is, the molar ratio of the oxidant to the sulfur content of the fuel is 5. In combination with Application Examples 10 and 11, BT is difficult to remove by oxidative desulfurization, and 4,6-DMDBT also has a relatively good removal rate.

[0093] Comparative Example

[0094] The raw material halloysite (ie, raw HNT) in Example 1 was calcined at 500° C. for 3 hours to obtain calcined halloysite, which was labeled as HNT-500.

[0095] The sodium tungstate of Example 1 was calcined at 500° C. for 3 hours to obtain calcined halloysite, which was labeled as W-500.

[0096] The raw materials of Example 1, namely, raw HNT, sodium tungstate (ie, Na2WO4·2H2O), HNT-500 and W-500, were used to replace the catalysts in Example 3 in equal amounts to conduct catalytic experiments, and the desulfurization rates were calculated. The results are as follows: Figure 2 As shown. Figure 2 It can be seen that the desulfurization rates of raw halloysite (raw HNT), sodium tungstate (Na2WO4·2H2O), HNT-500 and W-500 are all lower than 10%, which is significantly lower than that of the modified halloysite prepared in Example 1.

[0097] The catalyst after reaction was obtained by filtration, and the catalyst was dried to remove the water brought by H2O2, and new oil and H2O2 were added again. A cycle experiment was carried out. It was measured that the desulfurization rate did not decrease significantly after 4 reactions, and the desulfurization rate is shown in Table 2.

[0098] Table 2 Cycle test when the model oil is DBT

[0099]

[0100]

[0101] It can be seen from Table 2 that the catalyst after 5 cycles still has a high desulfurization rate for DBT.

[0102] It should be noted that the modified halloysite prepared in Examples 2-4 has a desulfurization performance comparable to that of the modified halloysite prepared in Example 1.

[0103] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for preparing modified halloysite, characterized in that: The following steps are involved: S1, mixing halloysite, sodium tungstate and water to obtain an intermediate product W / HNT; S2. Mix and stir the intermediate product W / HNT, cyclohexane and hexadecyltrimethoxysilane to obtain modified halloysite.

2. The method for preparing modified halloysite according to claim 1, characterized in that: In step S1, the material ratio of the halloysite, the sodium tungstate and water is 1 g: (0.01-0.05) g: (10-15) mL.

3. The method for preparing modified halloysite according to claim 1, characterized in that: In step S1, the temperature of the mixing and stirring is 20-35°C, and the time of the mixing and stirring is 20-24 hours.

4. The method for preparing modified halloysite according to claim 1, characterized in that: In step S2, the material ratio of the intermediate product W / HNT, the cyclohexane and the hexadecyltrimethoxysilane is 1 g:(10-15) mL:(1-3) μL.

5. The method for preparing modified halloysite according to claim 1, characterized in that: In step S2, the temperature of the mixing and stirring is 20-35°C, and the time of the mixing and stirring is 20-24 hours.

6. A modified halloysite, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 5.

7. An oxidative desulfurization catalyst, characterized in that: The invention comprises the modified halloysite prepared by the preparation method according to any one of claims 1 to 5 or the modified halloysite according to claim 6.

8. Use of the modified halloysite prepared by the preparation method according to any one of claims 1 to 5 or the modified halloysite according to claim 6 in oxidative desulfurization of fuel oil.

9. The use according to claim 8, characterized in that: include: The fuel, the oxidant and the modified halloysite are mixed and reacted.

10. The use according to claim 9, characterized in that: The oxidant is a hydrogen peroxide solution with a volume concentration of 25%-35%; and / or, the temperature of the mixed reaction is 40-70°C; and / or, the volume ratio of the oxidant to the fuel is (0.005-0.0055):1; and / or, the dosage ratio of the modified halloysite to the fuel is (0.004-0.005) g:1 mL.

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