Method for preparing succinic anhydride and application thereof

Abstract

The invention relates to the technical field of butanedioic anhydride preparation, and discloses a method for preparing butanedioic anhydride and application thereof. According to the method provided by the invention, succinic anhydride can be prepared through maleic anhydride hydrogenation reaction at near room temperature, and the effects of high maleic anhydride conversion rate and high succinic anhydride selectivity are achieved. Therefore, compared with the existing maleic anhydride hydrogenation method, the method provided by the invention not only has an excellent reaction effect, but also can omit the heating operation in the reaction process and reduce the reaction energy consumption, and is more in line with the requirements of green and sustainable industrial production.

Description

Technical Field

[0001] This invention relates to the field of succinic anhydride preparation technology, specifically to a method for preparing succinic anhydride and its application. Background Technology

[0002] Succinic anhydride is an important intermediate for organic compounds with wide applications in pharmaceuticals, pesticides, and materials. In particular, with the widespread use of biodegradable materials (PBS, PBAT, etc.), the demand for succinic acid, as one of the monomers in these materials, is increasing year by year.

[0003] The main industrial methods for producing succinic anhydride include bio-fermentation, succinic acid dehydration, and maleic anhydride catalytic hydrogenation. Among these, maleic anhydride hydrogenation is the most promising succinic anhydride production process due to its advantages of simple process flow, convenient operation, high equipment utilization, low operating cost, and high product purity.

[0004] For example, CN103769117A discloses a method for synthesizing succinic anhydride by hydrogenation of maleic anhydride using a cobalt-nickel catalyst supported on activated carbon as the active component; however, this method requires a high reaction temperature during the hydrogenation reaction. CN105833863A discloses a supported catalyst using palladium as the active component, and a method for preparing succinic anhydride by hydrogenation of maleic anhydride based on this catalyst; however, the use of precious metals makes this method costly. CN117983268A discloses a method for preparing succinic anhydride by hydrogenation of maleic anhydride using a catalyst modified with N and C elements, with a reaction temperature of 50-80℃ for maleic anhydride hydrogenation.

[0005] Therefore, it is evident that in existing methods for preparing succinic anhydride by hydrogenation of maleic anhydride, although researchers have made various improvements to the catalysts, the reaction temperature remains high, resulting in high energy consumption and failing to meet the "energy saving and carbon reduction" requirements of green and sustainable industrial production. Therefore, there is an urgent need to develop methods that can further reduce the reaction temperature of maleic anhydride hydrogenation while ensuring reactivity. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of high reaction temperatures in the hydrogenation of maleic anhydride in existing technologies, and to provide a method for preparing succinic anhydride and its application. The method provided by this invention enables the preparation of succinic anhydride by hydrogenation of maleic anhydride at room temperature with high conversion and high selectivity.

[0007] To achieve the above objectives, a first aspect of the present invention provides a method for preparing succinic anhydride, the method comprising contacting maleic anhydride with a thin-film nickel-based catalyst and converting maleic anhydride into succinic anhydride under catalytic hydrogenation conditions.

[0008] The thin-film nickel-based catalyst includes a dispersant and an active component Ni, wherein the dispersant is alumina and the most probable pore size of the thin-film nickel-based catalyst is 35-100 nm.

[0009] The second aspect of the present invention provides a sheet-like nickel-based catalyst used in the method described in the first aspect.

[0010] A third aspect of the present invention provides a method for preparing a sheet-like nickel-based catalyst for catalytic hydrogenation of maleic anhydride, the method comprising: contacting a nickel source with a mixed base in a solution system to obtain a suspension for reaction;

[0011] The nickel source is provided in the form of solution A, and the mixed alkali is provided in the form of solution B, wherein solution B contains an alkaline compound.

[0012] A fourth aspect of the present invention provides a catalyst prepared according to the method described in the third aspect.

[0013] The fifth aspect of the present invention provides the use of the method of the first aspect, and / or the catalyst of the second or fourth aspect, and / or the method of the third aspect in at least one of the following:

[0014] (1) Application in reducing the reaction temperature of maleic anhydride hydrogenation to prepare succinic anhydride;

[0015] (2) Application in improving the conversion rate and / or selectivity of maleic anhydride hydrogenation to succinic anhydride.

[0016] Through the above technical solution, the present invention can achieve at least the following beneficial effects:

[0017] (1) The method provided by the present invention uses a catalyst with excellent catalytic activity and a large most probable pore size, which is beneficial to the mass transfer process in the reaction and has a high maleic anhydride conversion rate and succinic anhydride selectivity.

[0018] (2) The method provided by the present invention can be carried out at a lower temperature (e.g., at room temperature), which reduces the energy consumption of maleic anhydride hydrogenation reaction, reduces carbon emissions, and is more green and environmentally friendly, which can meet the needs of sustainable industrial production.

[0019] (3) The method provided by the present invention does not require additional heating during the reaction process, which reduces the investment in equipment construction and can also improve the safety of the reaction device, making it suitable for large-scale production and promotion. Attached Figure Description

[0020] Figure 1 The images show the XRD patterns of the catalysts prepared in Preparation Examples 1-5 and Comparative Preparation Examples 1-3.

[0021] Figure 2These are pore size distribution diagrams of the catalysts prepared in Preparation Examples 1-5 and Comparative Preparation Examples 1-3;

[0022] Figure 3 This is a TEM image of the catalyst prepared in Preparation Example 1. Detailed Implementation

[0023] The endpoints and any values ​​of the ranges 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 endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0024] In this invention, unless otherwise specified, "sheet-like nickel-based catalyst" and "nickel-based catalyst" have the same meaning and both refer to the catalyst used in the method provided by this invention, which can also be called "the catalyst of this invention".

[0025] In this invention, unless otherwise specified, "room temperature" or "near room temperature" refers to the normal indoor temperature, which is usually 20-30℃.

[0026] The inventors of this invention ingeniously discovered during their research that when using a nickel-based catalyst to catalyze the hydrogenation of maleic anhydride to prepare succinic anhydride, a larger most probable pore size of the catalyst is more conducive to the mass transfer process in the reaction, thereby improving the conversion rate of maleic anhydride and the selectivity of succinic anhydride. Through further research, the inventors also found that when using a nickel-based catalyst with a larger most probable pore size for the hydrogenation reaction of maleic anhydride, increasing the nickel dispersion in the catalyst can further improve the reaction effect. Based on this, by further adjusting and coordinating the catalyst preparation process and the conditions of the maleic anhydride hydrogenation reaction, even better reaction results can be achieved.

[0027] Based on this, the first aspect of the present invention provides a method for preparing succinic anhydride, the method comprising contacting maleic anhydride with a thin-film nickel-based catalyst and converting maleic anhydride into succinic anhydride under catalytic hydrogenation conditions.

[0028] The thin-film nickel-based catalyst includes a dispersant and an active component Ni, wherein the dispersant is alumina, and the most probable pore size of the thin-film nickel-based catalyst is not less than 15 nm.

[0029] "Most probable pore size" refers to the pore size with the highest probability of occurrence in the pore size distribution, which is located at the peak position in the pore size distribution diagram. In this invention, the most probable pore size refers to the pore size value corresponding to the peak position of the curve in the pore size distribution diagram plotted by detecting the pore size distribution of the catalyst using the BET method.

[0030] According to a preferred embodiment of the present invention, the most probable pore size of the sheet-like nickel-based catalyst is 35-100 nm, preferably 40-70 nm.

[0031] For example, the most probable pore size of the sheet-like nickel-based catalyst can be 35nm, 40nm, 45nm, 50nm, 55nm, 60nm, 65nm, 70nm, 75nm, 80nm, 85nm, 90nm, 95nm, or 100nm, or it can be any range of any two of the above values, or any intermediate value in that range.

[0032] Preferably, based on the total weight of the nickel-based catalyst, the Ni content, in elemental terms, is not less than 20 wt.%, and more preferably 30-80 wt.%.

[0033] For example, based on the total weight of the nickel-based catalyst, the Ni content, in terms of elements, can be 20 wt.%, 25 wt.%, 30 wt.%, 35 wt.%, 40 wt.%, 45 wt.%, 50 wt.%, 55 wt.%, 60 wt.%, 65 wt.%, 70 wt.%, 75 wt.%, 80 wt.%, or a range consisting of any two of the above values, or any intermediate value within that range.

[0034] Preferably, the Ni dispersion in the nickel-based catalyst is 10-20%, more preferably 11-16%.

[0035] For example, in the nickel-based catalyst, the dispersion of Ni can be 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15%, 15.5%, 16%, 16.5%, 17%, 17.5%, 18%, 18.5%, 19%, 19.5%, or 20%, or it can be a range consisting of any two of the above values, or any intermediate value within that range.

[0036] In this invention, "dispersion degree" is a characterizing parameter of the degree of Ni dispersion in the catalyst. Typically, the amount of hydrogen adsorbed by the catalyst can be detected using hydrogen chemisorption, and the Ni dispersion degree of the catalyst can be calculated using the following formula (Equation I).

[0037]

[0038] In Formula I, D% is the Ni dispersion of the catalyst to be tested (in %), and V ad M is the saturated adsorption capacity of the catalyst to be tested for hydrogen. Ni It is the molar mass of nickel, m catThe mass of the catalyst being tested is measured, and wt% represents the nickel content in the catalyst being tested.

[0039] According to a preferred embodiment of the present invention, the catalytic hydrogenation conditions include: a reaction temperature not exceeding 45°C, preferably 20-30°C.

[0040] For example, the reaction temperature can be 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, 30℃, 32℃, 34℃, 36℃, 38℃, 40℃, 42℃, 44℃, or 45℃, or it can be a range consisting of any two of the above values, or any intermediate value within that range.

[0041] Preferably, the catalytic hydrogenation conditions further include a reaction pressure of 1-5 MPa.

[0042] For example, the reaction pressure can be 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa, 4.5 MPa, or 5 MPa, or it can be a range consisting of any two of the above values, or any intermediate value within that range.

[0043] According to some preferred embodiments of the present invention, the catalytic hydrogenation conditions include: a reaction temperature of 20-25°C and a reaction pressure of 3-5 MPa.

[0044] According to a preferred embodiment of the present invention, the method further includes a step of reducing the sheet-like nickel-based catalyst before the reaction.

[0045] Any method used in the art for reducing nickel-based catalysts, especially nickel-based catalysts used in the hydrogenation of maleic anhydride to prepare succinic anhydride, is applicable to this invention. Preferably, the method for reducing the sheet-like nickel-based catalyst includes: reducing the sheet-like catalyst at 400-600°C in a hydrogen atmosphere.

[0046] A second aspect of the present invention provides a sheet-like nickel-based catalyst used in the method described in the first aspect. The characteristics of this sheet-like nickel-based catalyst are as previously described and will not be repeated here.

[0047] A third aspect of the present invention provides a method for preparing a sheet-like nickel-based catalyst for catalytic hydrogenation of maleic anhydride, the method comprising: contacting a nickel source with a mixed base in a solution system to obtain a suspension for reaction;

[0048] The nickel source is provided in the form of solution A, and the mixed alkali is provided in the form of solution B, wherein solution B contains an alkaline compound.

[0049] In this invention, solution A is an aqueous solution containing Ni. According to a preferred embodiment of the invention, solution A is an aqueous solution of an inorganic nickel salt. Preferably, the inorganic nickel salt is selected from at least one of nickel carbonate, nickel nitrate, and nickel sulfate.

[0050] Preferably, the concentration of nickel salt in solution A is 0.05-4M, more preferably 0.1-3M.

[0051] For example, in solution A, the concentration of the nickel salt can be 0.05M, 0.1M, 0.15M, 0.2M, 0.25M, 0.3M, 0.4M, 0.5M, 0.6M, 0.7M, 0.8M, 0.9M, 1M, 1.2M, 1.4M, 1.6M, 1.8M, 2M, 2.2M, 2.4M, 2.6M, 2.8M, or 3M, or a range consisting of any two of the above values, or any intermediate value within that range. According to some preferred embodiments of the present invention, in solution A, the concentration of the nickel salt is 0.1-1.5M.

[0052] According to a preferred embodiment of the present invention, solution B comprises an alkaline compound, an aluminate, and a polymer containing nitrogen-containing heterocyclic side groups.

[0053] Preferably, the alkaline compound is selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate.

[0054] More preferably, the concentration of the alkaline compound in solution B is 0.01-4M, and even more preferably 0.1-2M.

[0055] For example, the concentration of the alkaline compound in solution B can be 0.01M, 0.05M, 0.1M, 0.15M, 0.2M, 0.25M, 0.3M, 0.35M, 0.4M, 0.45M, 0.5M, 0.6M, 0.7M, 0.8M, 0.9M, 1M, 1.2M, 1.4M, 1.6M, 1.8M, 2M, 2.5M, 3M, 3.5M, or 4M, or a range consisting of any two of the above values, or any intermediate value within that range. According to some preferred embodiments of the present invention, the concentration of the alkaline compound in solution B is 0.1-1M.

[0056] Preferably, the aluminate is selected from at least one of sodium aluminate and potassium aluminate.

[0057] More preferably, the concentration of aluminate in solution B is 0.01-2M, and even more preferably 0.05-1M.

[0058] For example, the concentration of aluminate in solution B can be 0.01M, 0.05M, 0.1M, 0.15M, 0.2M, 0.25M, 0.3M, 0.35M, 0.4M, 0.45M, 0.5M, 0.6M, 0.7M, 0.8M, 0.9M, 1M, 1.2M, 1.4M, 1.6M, 1.8M, or 2M, or a range consisting of any two of the above values, or any intermediate value within that range. According to some preferred embodiments of the present invention, the concentration of aluminate in solution B is 0.1-0.5M.

[0059] Preferably, the polymer containing nitrogen-containing heterocyclic side groups is polyvinylimidazole.

[0060] More preferably, the concentration of the high molecular weight polymer (e.g., polyvinylimidazole) containing nitrogen-containing heterocyclic side groups in solution B is 0.01-0.5 M, more preferably 0.01-0.1 M.

[0061] For example, the concentration of polyvinylimidazole in solution B can be 0.01M, 0.02M, 0.03M, 0.04M, 0.05M, 0.06M, 0.07M, 0.08M, 0.09M, 0.1M, 0.15M, 0.2M, 0.22M, 0.24M, 0.26M, 0.28M, 0.3M, 0.35M, 0.4M, 0.42M, 0.44M, 0.46M, 0.48M, or 0.5M, or a range consisting of any two of the above values, or any intermediate value within that range. According to some preferred embodiments of the present invention, the concentration of aluminate in solution B is 0.1-0.5M.

[0062] More preferably, the weight-average molecular weight of the polyvinylimidazole is 10. 3 -10 6 g / mol, preferably 10 g / mol 4 -10 5 g / mol. "10" 3 -10 6 "g / mol" refers to the weight-average molecular weight of the polyvinylimidazole used in this invention, which can be 10 g / mol. 3 -10 6 Within the g / mol level range. "10 3 "g / mol level" refers to a weight-average molecular weight on the order of 10. 3 For example, 1×10 3 g / mol, 5×10 3 g / mol, 9.9×10 3 g / mol and similar values ​​belong to "10". 3 "g / mol level". Therefore, the weight-average molecular weight of the polyvinylimidazole used in this invention can be greater than or equal to 1×10⁻⁶ g / mol.3 g / mol to less than 1×10 7 Within the range of g / mol, preferably greater than or equal to 1×10 4 g / mol to less than 1×10 6 Within the range of g / mol.

[0063] For example, the weight-average molecular weight of the polyvinylimidazole can be 1 × 10⁻⁶. 3 g / mol, 5×10 3 g / mol, 9.9×10 3 g / mol, 1×10 4 g / mol, 2×10 4 g / mol, 3×10 4 g / mol, 4×10 4 g / mol, 5×10 4 g / mol, 6×10 4 g / mol, 7×10 4 g / mol, 8×10 4 g / mol, 9×10 4 g / mol, 9.9×10 4 g / mol, 1×10 5 g / mol, 2×10 5 g / mol, 3×10 5 g / mol, 4×10 5 g / mol, 5×10 5 g / mol, 6×10 5 g / mol, 7×10 5 g / mol, 8×10 5 g / mol, 9×10 5 g / mol, 9.9×10 5 g / mol, 1×10 6 g / mol, 5×10 6 g / mol, 9.9×10 6 g / mol, or it can be any range of the two values ​​mentioned above, or any intermediate value within that range.

[0064] According to a preferred embodiment of the present invention, the reaction conditions include: pH 8-12, preferably 9-11; temperature 20-120°C; and time 10-360 min.

[0065] For example, the reaction pH can be 8, 9, 10, 11, or 12, or it can be any range of any two of the above values, or any intermediate value within that range.

[0066] For example, the reaction temperature can be 20℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, or 120℃, or it can be a range consisting of any two of the above values, or any intermediate value in that range.

[0067] For example, the reaction time can be 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 120 min, 150 min, 180 min, 200 min, 220 min, 250 min, 280 min, 300 min, 320 min, 340 min, or 360 min, or it can be a range consisting of any two of the above values, or any intermediate value within that range.

[0068] According to some preferred embodiments of the present invention, the reaction conditions include: pH 8-11; temperature 60-120°C; time 10-360 min.

[0069] According to a preferred embodiment of the present invention, the method further includes the steps of sequentially filtering, washing, and drying the reaction products after the reaction is completed. The purpose of these steps is to filter out the solids (i.e., the obtained catalyst) from the reaction products, remove the residual reaction system components on their surface, and dry them to obtain a usable catalyst.

[0070] A fourth aspect of the present invention provides a catalyst prepared according to the method described in the third aspect.

[0071] The fifth aspect of the present invention provides the use of the method of the first aspect, and / or the catalyst of the second or fourth aspect, and / or the method of the third aspect in at least one of the following:

[0072] (1) Application in reducing the reaction temperature of maleic anhydride hydrogenation to prepare succinic anhydride;

[0073] (2) Application in improving the conversion rate and / or selectivity of maleic anhydride hydrogenation to succinic anhydride.

[0074] According to some preferred embodiments of the present invention, the method for preparing succinic anhydride according to the first aspect may include a process of providing the sheet-like nickel-based catalyst.

[0075] Preferably, the method for preparing succinic anhydride according to the first aspect includes a process for preparing a sheet-like nickel-based catalyst using the method described in the third aspect.

[0076] The specific methods and conditions for preparing thin-film nickel-based catalysts and the methods for preparing succinic anhydride have been described in detail above and will not be repeated here.

[0077] The present invention will be described in detail below through embodiments. It should be understood that the following embodiments are only for illustrative purposes to further explain and illustrate the content of the present invention, and are not intended to limit the present invention.

[0078] Unless otherwise specified, all reagents and materials used in the following examples were commercially available products from reputable chemical reagent / material suppliers, and all reagents were of analytical grade. The polyvinylimidazole used in the following examples was purchased from Inocare, with a weight-average molecular weight of approximately 1 × 10⁻⁶. 4 -1×10 5 g / mol.

[0079] In the following examples, unless otherwise specified, X-ray fluorescence spectrometry (XRF) was used to analyze and determine the elemental content in the prepared catalysts; the dispersion of nickel in the catalysts was detected by hydrogen chemisorption, and the specific method is as follows:

[0080] Using a Micron Autochem 2920 instrument, the catalyst was treated at 500℃ for 2 hours in a pure hydrogen atmosphere, followed by purging with high-purity argon at 500℃ for 1 hour. The temperature was then lowered to 45℃, and high-purity hydrogen pulse adsorption was switched until adsorption saturation. Based on the test results, the nickel dispersion (D%) was calculated using the following formula:

[0081]

[0082] Where V ad M is the saturated adsorption capacity of hydrogen. Ni It is the molar mass of nickel, m cat It refers to the mass of the catalyst packed, and wt% is the nickel content in the catalyst.

[0083] Preparation Example 1

[0084] This preparation example illustrates the preparation of the sheet-like nickel-based catalyst S-1 used in this invention.

[0085] (1) Prepare a 0.75M nickel nitrate aqueous solution as solution A; prepare a mixed solution of sodium aluminate, sodium carbonate and polyvinyl imidazole with concentrations of 0.25M, 0.5M and 0.05M as solution B;

[0086] (2) Under the conditions of 50℃ and stirring, solution A and solution B were mixed. During the mixing process, the pH of the system was kept at 11. When the volume of the mixed solution reached 200mL, the mixing was stopped and the mixed solution was transferred to a hydrothermal reactor. The reaction was carried out at 120℃ for 10min. The reaction product was filtered and the filtered solid material was washed with deionized water. The product was then dried at 60℃ for 4h to obtain thin-film nickel-based catalyst S-1.

[0087] Analysis revealed that catalyst S-1 contained 71 wt.% Ni and 29 wt.% alumina. The elemental composition of catalyst S-1 was determined using XRD, and the resulting XRD pattern is shown below. Figure 1 As shown in the figure, the peak around 17° on the horizontal axis indicates that no nickel hydroxide impurity is formed in catalyst S-1. Its pore size distribution is as follows... Figure 2 As shown in the figure, the most probable pore size of catalyst S-1 is 40 nm. The catalyst S-1 was examined using TEM (transmission electron microscopy), and the resulting TEM image is shown below. Figure 3 As shown, catalyst S-1 has a sheet-like structure. Hydrogen chemisorption analysis revealed that the nickel dispersion in S-1 was 12.4%.

[0088] Preparation Example 2

[0089] This preparation example illustrates the preparation of the sheet-like nickel-based catalyst S-2 used in this invention.

[0090] (1) Prepare a 0.75M nickel nitrate aqueous solution as solution A; prepare a mixed solution of sodium aluminate, sodium carbonate and polyvinyl imidazole with concentrations of 0.25M, 0.5M and 0.05M as solution B;

[0091] (2) Under the conditions of 50℃ and stirring, solution A and solution B were mixed. During the mixing process, the pH of the system was kept at 10. When the volume of the mixed solution reached 200mL, the mixing was stopped and the mixed solution was transferred to a hydrothermal reactor. The reaction was carried out at 80℃ for 120min. The reaction product was filtered and the filtered solid material was washed with deionized water. The product was then dried at 60℃ for 10h to obtain thin-film nickel-based catalyst S-2.

[0092] Analysis revealed that catalyst S-2 contained 66 wt.% Ni and 34 wt.% alumina. The elemental composition of catalyst S-2 was determined using XRD, and the resulting XRD pattern is shown below. Figure 1 As shown in the figure, the peak around 17° on the horizontal axis indicates that no nickel hydroxide impurity is formed in catalyst S-2. Its pore size distribution is as follows... Figure 2 As shown, from Figure 2 It is known that the most probable pore size of catalyst S-1 is 49 nm. Catalyst S-1 was examined using TEM (transmission electron microscopy), and the obtained TEM image is consistent with... Figure 3 Similarly, it can be seen that catalyst S-2 has a sheet-like structure. Furthermore, hydrogen chemisorption analysis revealed that the nickel dispersion in S-1 was 14.2%.

[0093] Preparation Example 3

[0094] This preparation example illustrates the preparation of the sheet-like nickel-based catalyst S-3 used in this invention.

[0095] (1) Prepare a 0.75M nickel nitrate aqueous solution as solution A; prepare a mixed solution of sodium aluminate, sodium carbonate and polyvinyl imidazole with concentrations of 0.25M, 0.5M and 0.05M as solution B;

[0096] (2) Under the conditions of 50℃ and stirring, solution A and solution B were mixed. During the mixing process, the pH of the system was kept at 9. When the volume of the mixed solution reached 200mL, the mixing was stopped and the mixed solution was transferred to a hydrothermal reactor and reacted at 60℃ for 360min. The reaction product was filtered and the filtered solid material was washed with deionized water and dried at 60℃ for 12h to obtain thin-film nickel-based catalyst S-3.

[0097] Analysis revealed that catalyst S-3 contained 58 wt.% Ni and 42 wt.% alumina. The elemental composition of catalyst S-3 was determined using XRD, and the resulting XRD pattern is shown below. Figure 1 As shown in the figure, the peak around 17° on the horizontal axis indicates that no nickel hydroxide impurity is formed in catalyst S-3. Its pore size distribution is as follows... Figure 2 As shown, from Figure 2 It is known that the most probable pore size of catalyst S-3 is 70 nm. The catalyst S-3 was examined using TEM (transmission electron microscopy), and the obtained TEM image is consistent with... Figure 3 Similarly, it can be seen that catalyst S-3 has a sheet-like structure. Furthermore, hydrogen chemisorption analysis revealed that the nickel dispersion in S-3 was 15.1%.

[0098] Preparation Example 4

[0099] This preparation example illustrates the preparation of the sheet-like nickel-based catalyst S-4 used in this invention.

[0100] (1) Prepare a 0.1M nickel nitrate aqueous solution as solution A; prepare a mixed solution of sodium aluminate, sodium carbonate and polyvinyl imidazole with concentrations of 0.25M, 0.5M and 0.05M as solution B;

[0101] (2) Under the conditions of 50℃ and stirring, solution A and solution B were mixed. During the mixing process, the pH of the system was kept at 8. When the volume of the mixed solution reached 200mL, the mixing was stopped and the mixed solution was transferred to a hydrothermal reactor and reacted at 60℃ for 120min. The reaction product was filtered and the filtered solid material was washed with deionized water and dried at 60℃ for 12h to obtain thin-film nickel-based catalyst S-4.

[0102] Analysis revealed that catalyst S-4 contained 31 wt.% Ni and 69 wt.% alumina. The elemental composition of catalyst S-4 was determined using XRD, and the resulting XRD pattern is shown below. Figure 1As shown in the figure, the peak around 17° on the horizontal axis indicates that no nickel hydroxide impurity is formed in catalyst S-4. Its pore size distribution is as follows... Figure 2 As shown, from Figure 2 It is known that the most probable pore size of catalyst S-4 is 50 nm. TEM transmission electron microscopy was used to examine catalyst S-4, and the obtained TEM image is consistent with... Figure 3 Similarly, it can be seen that catalyst S-4 has a sheet-like structure. Furthermore, hydrogen chemisorption analysis revealed that the nickel dispersion in S-4 was 12.2%.

[0103] Preparation Example 5

[0104] This preparation example illustrates the preparation of the sheet-like nickel-based catalyst S-5 used in this invention.

[0105] (1) Prepare a 1.5M nickel nitrate aqueous solution as solution A; prepare a mixed solution of sodium aluminate, sodium carbonate and polyvinyl imidazole with concentrations of 0.5M, 0.1M and 0.1M respectively as solution B;

[0106] (2) Under the conditions of 50℃ and stirring, solution A and solution B were mixed. During the mixing process, the pH of the system was kept at 9. When the volume of the mixed solution reached 200mL, the mixing was stopped and the mixed solution was transferred to a hydrothermal reactor. The reaction was carried out at 60℃ for 120min. The reaction product was filtered and the filtered solid material was washed with deionized water. The product was then dried at 150℃ for 12h to obtain the thin-film nickel-based catalyst S-5.

[0107] Analysis revealed that catalyst S-5 contained 62 wt.% Ni and 38 wt.% alumina. The elemental composition of catalyst S-5 was determined using XRD, and the resulting XRD pattern is shown below. Figure 1 As shown in the figure, the peak around 17° on the horizontal axis indicates that no nickel hydroxide impurity is formed in catalyst S-5. Its pore size distribution is as follows... Figure 2 As shown, from Figure 2 It is known that the most probable pore size of catalyst S-5 is 53 nm. The catalyst S-5 was examined using TEM (transmission electron microscopy), and the obtained TEM image is consistent with... Figure 3 Similarly, it can be seen that catalyst S-5 has a sheet-like structure. Furthermore, hydrogen chemisorption analysis revealed that the nickel dispersion in S-5 was 13.1%.

[0108] Comparative Preparation Example 1

[0109] The control Ni catalyst D-1 was prepared by the conventional coprecipitation method.

[0110] (1) Prepare a mixed aqueous solution of nickel nitrate and aluminum nitrate with concentrations of 0.75M and 0.25M respectively as solution A; prepare a mixed aqueous solution of sodium hydroxide and sodium carbonate with concentrations of 1.2M and 0.8M respectively as solution B;

[0111] (2) Under the conditions of 50℃ and stirring, solution A and solution B were mixed. During the mixing process, the pH of the system was kept at 9. When the volume of the mixed solution reached 200mL, the mixing was stopped and the mixture was transferred to a hydrothermal reactor. The reaction was carried out at 60℃ for 120min. The reaction product was filtered and the filtered solid material was washed with deionized water. The product was then dried at 60℃ for 12h to obtain catalyst D-1.

[0112] The Ni content in catalyst D-1 was found to be 63 wt.%. The elemental composition of catalyst D-1 was determined using XRD, and the resulting XRD pattern is shown below. Figure 1 As shown in the figure, the peak around 17° on the horizontal axis indicates that nickel hydroxide, an impurity, was formed in catalyst D-1. Its pore size distribution is as follows... Figure 2 As shown, from Figure 2 It is known that the most probable pore size of catalyst D-1 is 10 nm. Furthermore, hydrogen chemisorption analysis revealed that the nickel dispersion in D-1 is 6.9%.

[0113] Comparative Preparation Example 2

[0114] The nickel-based catalyst was prepared using the same method as in Example 1, except that sodium aluminate was not added to solution B. All other operations and conditions were the same as in Example 1, yielding basic nickel carbonate catalyst D-2.

[0115] The Ni content in catalyst D-2 was found to be 80 wt.%. The elemental composition of catalyst D-2 was determined using XRD, and the resulting XRD pattern is shown below. Figure 1 As shown in the figure, catalyst D-2 is basic nickel carbonate. Its pore size distribution is as follows. Figure 2 As shown, from Figure 2 It can be seen that catalyst D-2 lacks pore distribution characteristics. Furthermore, hydrogen chemisorption analysis revealed that the nickel dispersion in D-2 was 0.03%.

[0116] Comparative preparation example 3

[0117] The nickel-based catalyst was prepared using the same method as in Example 1, except that polyvinylimidazole was not added to solution B. All other operations and conditions were the same as in Example 1, yielding catalyst D-3.

[0118] The Ni content in catalyst D-3 was determined to be 70 wt.%. The elemental composition of catalyst D-3 was analyzed using XRD, and the resulting XRD pattern is shown below. Figure 1As shown in the figure, the peak around 17° on the horizontal axis indicates that nickel hydroxide, an impurity, was formed in catalyst D-3. Its pore size distribution is as follows... Figure 2 As shown, from Figure 2 It is known that the most probable pore size of catalyst D-3 is 3.5 nm. Furthermore, hydrogen chemisorption analysis revealed that the nickel dispersion in D-3 is 6.7%.

[0119] Example 1

[0120] The catalyst obtained in Preparation Example 1 was used to carry out the hydrogenation reaction of maleic anhydride to prepare succinic anhydride. The specific method is as follows:

[0121] (1) Catalyst activation: Catalyst S-1 is loaded into a quartz tube, high-purity hydrogen is introduced at a flow rate of 300 mL / min, and the temperature is raised to 500 °C to reduce the catalyst for 4 hours; then high-purity nitrogen is switched at a flow rate of 300 mL / min, and the catalyst is taken out when the temperature drops to the set temperature to obtain the activated catalyst.

[0122] (2) Catalyst Evaluation: 5g of activated catalyst, 5g of maleic anhydride, and 95g of tetrahydrofuran were loaded into a high-pressure reactor. The system was adjusted to the required pressure using hydrogen gas to bring the hydrogen and maleic anhydride into contact with the catalyst. The maleic anhydride hydrogenation reaction was carried out under the conditions shown in Table 1. The composition of the solution after the reaction was analyzed using gas chromatography with an FID detector. Based on the detection results, the maleic anhydride conversion and succinic anhydride selectivity were calculated using the following formulas:

[0123]

[0124]

[0125] For detailed results, please refer to Table 1.

[0126] Example 2

[0127] The maleic anhydride hydrogenation reaction was carried out in the same manner as in Example 1 to prepare succinic anhydride. The difference was that the catalyst was replaced with the sheet-like nickel-based catalyst S-2 obtained in Preparation Example 2; the reaction conditions are shown in Table 1.

[0128] The solution composition after the reaction was analyzed and the maleic anhydride conversion and succinic anhydride selectivity were calculated using the method described in Example 1. The specific results are detailed in Table 1.

[0129] Example 3

[0130] The maleic anhydride hydrogenation reaction was carried out in the same manner as in Example 1 to prepare succinic anhydride. The difference was that the catalyst was replaced with the sheet-like nickel-based catalyst S-3 obtained in Preparation Example 3; the reaction conditions are shown in Table 1.

[0131] The solution composition after the reaction was analyzed and the maleic anhydride conversion and succinic anhydride selectivity were calculated using the method described in Example 1. The specific results are detailed in Table 1.

[0132] Example 4

[0133] The maleic anhydride hydrogenation reaction was carried out in the same manner as in Example 1 to prepare succinic anhydride. The difference was that the catalyst was replaced with the sheet-like nickel-based catalyst S-4 obtained in Preparation Example 4; the reaction conditions are shown in Table 1.

[0134] The solution composition after the reaction was analyzed and the maleic anhydride conversion and succinic anhydride selectivity were calculated using the method described in Example 1. The specific results are detailed in Table 1.

[0135] Example 5

[0136] The maleic anhydride hydrogenation reaction was carried out in the same manner as in Example 1 to prepare succinic anhydride. The difference was that the catalyst was replaced with the sheet-like nickel-based catalyst S-5 obtained in Preparation Example 5; the reaction conditions are shown in Table 1.

[0137] The solution composition after the reaction was analyzed and the maleic anhydride conversion and succinic anhydride selectivity were calculated using the method described in Example 1. The specific results are detailed in Table 1.

[0138] Comparative Example 1

[0139] Succinic anhydride was prepared by hydrogenation of maleic anhydride using the same method as in Example 1. The difference was that the catalyst was replaced with catalyst D-1 obtained in Comparative Preparation Example 1; the reaction conditions are shown in Table 1.

[0140] The solution composition after the reaction was analyzed and the maleic anhydride conversion and succinic anhydride selectivity were calculated using the method described in Example 1. The specific results are detailed in Table 1.

[0141] Comparative Example 2

[0142] Maleic anhydride was hydrogenated using the same method as in Example 1 to prepare succinic anhydride. The difference was that the catalyst was replaced with catalyst D-2 obtained in Comparative Preparation Example 2; the reaction conditions are shown in Table 1.

[0143] The solution composition after the reaction was analyzed and the maleic anhydride conversion and succinic anhydride selectivity were calculated using the method described in Example 1. The specific results are detailed in Table 1.

[0144] Comparative Example 3

[0145] Maleic anhydride was hydrogenated using the same method as in Example 1 to prepare succinic anhydride. The difference was that the catalyst was replaced with catalyst D-3 obtained in Comparative Preparation Example 3; the reaction conditions are shown in Table 1.

[0146] The solution composition after the reaction was analyzed and the maleic anhydride conversion and succinic anhydride selectivity were calculated using the method described in Example 1. The specific results are detailed in Table 1.

[0147] Table 1

[0148]

[0151] The test results in Table 1 show that the catalyst selected in this invention can achieve high conversion and high selectivity in the hydrogenation of maleic anhydride at room temperature (20-30℃). Furthermore, with specific reaction conditions, the conversion and selectivity of maleic anhydride can be further improved. A comparison of the results from Experiments 1 and 15 shows that changes in the choice of raw materials affect the catalytic activity of the final catalyst, leading to a decrease in conversion and selectivity. A comparison of Experiments 3-7 and 8-12 demonstrates that using the same catalyst, adjusting the reaction conditions can further enhance the reaction activity.

[0152] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing succinic anhydride, characterized in that, The method involves contacting maleic anhydride with a thin-film nickel-based catalyst and converting the maleic anhydride into succinic anhydride under catalytic hydrogenation conditions. The thin-film nickel-based catalyst includes a dispersant and an active component Ni, wherein the dispersant is alumina, and the most probable pore size of the thin-film nickel-based catalyst is not less than 15 nm.

2. The method according to claim 1, wherein, The most probable pore size of the sheet-like nickel-based catalyst is 35-100 nm, preferably 40-70 nm; Preferably, based on the total weight of the nickel-based catalyst, the Ni content, in elemental terms, is not less than 20 wt.%, and more preferably 30-80 wt.%. Preferably, the Ni dispersion in the nickel-based catalyst is 10-20%, more preferably 11-16%.

3. The method according to claim 1, wherein, The catalytic hydrogenation conditions include: a reaction temperature not exceeding 45°C, preferably 20-30°C; Preferably, the catalytic hydrogenation conditions further include a reaction pressure of 1-5 MPa.

4. The method according to any one of claims 1-3, wherein, The method further includes a step of reducing the sheet-like nickel-based catalyst before the reaction; Preferably, the method for reducing the sheet-like nickel-based catalyst includes: reducing the sheet-like catalyst at 400-600°C in a hydrogen atmosphere.

5. The sheet-like nickel-based catalyst used in the method of any one of claims 1-4.

6. A method for preparing a sheet-like nickel-based catalyst for catalytic hydrogenation of maleic anhydride, characterized in that, The method includes: contacting a nickel source with a mixed alkali in a solution system to obtain a suspension for reaction; The nickel source is provided in the form of solution A, and the mixed alkali is provided in the form of solution B, wherein solution B contains an alkaline compound.

7. The method according to claim 6, wherein, Solution A is an aqueous solution of an inorganic nickel salt, preferably selected from at least one of nickel carbonate, nickel nitrate, and nickel sulfate; Preferably, the concentration of nickel salt in solution A is 0.05-4M, more preferably 0.1-3M; And / or, solution B includes basic compounds, aluminates, and polymers containing nitrogen-containing heterocyclic side groups; Preferably, the alkaline compound is selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate, and preferably the concentration of the alkaline compound in solution B is 0.01-4M, more preferably 0.1-2M; Preferably, the aluminate is selected from at least one of sodium aluminate and potassium aluminate, and more preferably the concentration of aluminate in solution B is 0.01-2M, more preferably 0.05-1M; Preferably, the polymer containing nitrogen-containing heterocyclic side groups is polyvinylimidazole, and more preferably, the concentration of the polymer containing nitrogen-containing heterocyclic side groups in solution B is 0.01-0.5M, more preferably 0.01-0.1M; More preferably, the weight-average molecular weight of the polyvinylimidazole is 10. 3 -10 6 g / mol, preferably 10 g / mol 4 -10 5 g / mol.

8. The method according to claim 6, wherein, The reaction conditions include: pH 8-12, preferably 9-11; temperature 20-120℃; time 10-360 min; And / or, the method further includes the steps of sequentially filtering, washing and drying the reaction products after the reaction is completed.

9. The catalyst prepared by any one of claims 6-8.

10. The method of any one of claims 1-4, and / or the catalyst of claim 5 or 9, and / or the method of any one of claims 6-8, in at least one of the following: (1) Application in reducing the reaction temperature of maleic anhydride hydrogenation to prepare succinic anhydride; (2) Application in improving the conversion rate and / or selectivity of maleic anhydride hydrogenation to succinic anhydride.

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