DINP hydrogenation catalyst based on carbon sphere carrier, preparation method and application thereof

Abstract

The application belongs to the field of catalysts, and particularly discloses a DINP hydrogenation catalyst based on carbon sphere carriers, a preparation method and application thereof. The nickel-based DINP hydrogenation catalyst based on hollow mesoporous carbon spheres is used for diisononyl phthalate hydrogenation reaction, and the DINP conversion rate can be as high as 99.2%, and the DINCH selectivity can be as high as 99.3%.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of catalysts, and particularly relates to a DINP hydrogenation catalyst based on a carbon sphere carrier and a preparation method and application thereof. BACKGROUND

[0002] The cyclohexane dicarboxylic acid dialkyl ester plasticizer has the characteristics of no environmental toxicity, no carcinogenicity, no peroxisome proliferation, no biological accumulation, and no reproductive toxicity, and can be applied to the production of children's toys, medical supplies, PVC plastic particles, and cable and wire materials. In industrial production, the cyclohexane dicarboxylic acid dialkyl ester plasticizer is mainly prepared by one-step hydrogenation of phthalate.

[0003] BASF (US6284917, US6248924, US7355084) first proposed using a Ru-loaded eggshell type hydrogenation catalyst to hydrogenate the benzene ring of diisononyl phthalate (DINP) under the condition of 20Mpa, realizing the industrial production of diisononyl cyclohexane dicarboxylate ((DINCH)) and becoming the largest enterprise producing diisononyl cyclohexane dicarboxylate ((DINCH)). At present, the production of cyclohexane dicarboxylic acid dialkyl ester in China is almost zero, and still mainly relies on import. The catalyst used for hydrogenation of the benzene ring of diisononyl phthalate (DINP) in the current technology is usually a noble metal-based catalyst, and the noble metal content in the catalyst is relatively large, which has a large production cost pressure. At present, some researchers use nickel-based catalysts to replace noble metal-based catalysts for hydrogenation reaction, but the hydrogenation activity of the nickel-based catalyst is relatively low, and thus a large load is required. However, under high load, the conventional carrier has the problem of insufficient accessible specific surface area, resulting in insufficient hydrogenation activity of the catalyst, and it is difficult to truly realize the effective replacement of noble metal-based catalysts in the field of hydrogenation. SUMMARY

[0004] In view of the defects of insufficient hydrogenation activity of the catalyst in the preparation of diisononyl cyclohexane dicarboxylate in the prior art, the present application provides a DINP hydrogenation catalyst based on a carbon sphere carrier and a preparation method and application thereof.

[0005] To achieve the above-mentioned purpose, the following technical solutions are specifically included:

[0006] A preparation method of a diisononyl phthalate hydrogenation catalyst, comprising the following steps:

[0007] (1) adding ammonia water, tetrapropoxysilane, formaldehyde and m-dihydroxybenzene in a solvent for reaction, collecting the solid, washing and drying to obtain a carrier precursor;

[0008] (2) calcining the carrier precursor in an inert gas atmosphere, and then etching with alkali, washing and drying to obtain a carbon sphere carrier;

[0009] (3) loading nickel salt on the carbon sphere carrier by impregnation, and then calcining under hydrogen gas atmosphere to obtain the diisobutyl phthalate hydrogenation catalyst.

[0010] Preferably, the mass percentage of nickel in the diisobutyl phthalate hydrogenation catalyst is 15-50%.

[0011] Further preferably, the mass percentage of nickel in the diisobutyl phthalate hydrogenation catalyst is 30-40%.

[0012] Preferably, the carrier is a hollow carbon sphere and has a mesoporous structure.

[0013] The present application adopts a hard template method, uses a silica core as a sacrificial template, uses phenolic resin as a carbon material precursor, converts the resin into a carbon shell through calcination, and removes the silica template by using alkali etching treatment to obtain a hollow mesoporous carbon sphere carrier. Then, through processes such as impregnation, calcination and reduction, the active ingredients are loaded on the carrier to obtain a supported catalyst loaded with nickel metal. The hollow mesoporous carbon sphere carrier has abundant edge defect sites, a super-large specific surface area and stable physicochemical properties. The use of the carrier to disperse and load nickel metal can make up for the problems of insufficient specific surface area and blocked pores of the existing carrier after loading nickel, which leads to insufficient reaction activity of the catalyst. The catalyst of the present application is a nickel-based non-noble metal catalyst, has a large specific surface area, high hydrogenation catalytic activity, high product yield and few by-products, and can not use noble metals, so that high conversion rate and high target product selectivity can be achieved, and production cost can be reduced.

[0014] Preferably, in step (1), the reaction time is 12-48h.

[0015] Preferably, in step (1), the solvent is an alcohol aqueous solution, and the volume ratio of alcohol to water is (60-120):(10-30), and the alcohol includes ethanol.

[0016] Preferably, in step (1), the mass ratio of ammonia water to tetrapropyl silane is 1:(2-8).

[0017] Preferably, in step (1), the mass ratio of formaldehyde to tetrapropyl silane is 1:(6-10).

[0018] Preferably, in step (1), the mass ratio of formaldehyde to resorcinol is 1:(0.8-2).

[0019] Preferably, in step (2), the calcination temperature is 700-900℃, and the calcination time is 1-5h.

[0020] Preferably, in steps (1) and (2), the drying temperature is 60-80℃, and the drying time is 12-48h.

[0021] Preferably, in step (2), the etching temperature is 80-110℃, and the etching time is 12-18h.

[0022] Preferably, in step (2), the alkali solution includes sodium hydroxide, potassium hydroxide solution, and the concentration of the alkali solution is 1-5mol / L.

[0023] Preferably, in step (3), the calcination temperature is 150-350℃, and the calcination time is 5-12h.

[0024] Preferably, in step (3), the impregnation temperature is 90-120℃, and the impregnation time is 2-48h.

[0025] Preferably, in step (3), during the impregnation, the concentration of the nickel salt is 10-20mol / L, and the mass ratio of the nickel salt to the carbon sphere carrier is (0.5-5):1.

[0026] Preferably, in step (3), the nickel salt is a corresponding water-soluble nickel salt.

[0027] Preferably, the water-soluble nickel salt includes but is not limited to a corresponding chloride salt, nitrate salt or sulfate salt, such as nickel nitrate, etc.

[0028] The application also provides an application of the diisononyl phthalate hydrogenation catalyst, and the diisononyl phthalate hydrogenation catalyst is used as a catalyst for preparing diisononyl cyclohexanedicarboxylate by hydrogenation reaction of diisononyl phthalate.

[0029] Preferably, the temperature of the hydrogenation reaction is 140-170℃; further preferably, the temperature of the hydrogenation reaction is 150-160℃.

[0030] Preferably, the pressure of the hydrogenation reaction is 4-7MPa; further preferably, the pressure of the hydrogenation reaction is 5-6MPa.

[0031] Preferably, the liquid space velocity of the raw material of the hydrogenation reaction is 0.1-0.45h -1 ; further preferably, the liquid space velocity of the raw material of the hydrogenation reaction is 0.2-0.3h -1 .

[0032] Preferably, the volume ratio of hydrogen to diisononyl phthalate in the hydrogenation reaction is (10-35):1; further preferably, the volume ratio of hydrogen to diisononyl phthalate in the hydrogenation reaction is (25-30):1.

[0033] Preferably, the hydrogenation reaction is carried out using a fixed-bed continuous hydrogenation reactor.

[0034] The present application uses a nickel-based DINP hydrogenation catalyst based on hollow mesoporous carbon spheres as a carrier to carry out the hydrogenation reaction of diisononyl phthalate, and the DINP conversion rate can be as high as 99.2%, and the DINCH selectivity can be as high as 99.3%.

[0035] Compared with the prior art, the present application has the following beneficial effects: the present application uses a DINP hydrogenation catalyst with a large specific surface area and hollow mesoporous carbon spheres as a carrier to load Ni active components, which can overcome the problems of catalyst channel blockage and small accessible specific surface area caused by high nickel loading, significantly improve the catalytic hydrogenation activity of the nickel-based catalyst, and has the characteristics of high selectivity and high activity, and has the potential to replace noble metal-based hydrogenation catalysts for the production of diisononyl cyclohexane dicarboxylate (DINCH) plasticizer. DETAILED DESCRIPTION

[0036] In order to better illustrate the purpose, technical scheme and advantages of the present application, the present application will be further described below through specific examples. Unless otherwise specified, the test methods used in the examples and / or comparative examples are conventional methods; and the materials, reagents, etc. used, unless otherwise specified, can be obtained from commercial channels.

[0037] Brief description of the following examples and comparative examples:

[0038] Example 1 is a preparation method of a nickel-based diisononyl phthalate hydrogenation catalyst using a hollow mesoporous carbon sphere with a large specific surface area as a carrier;

[0039] Examples 2-5 are catalyst process condition investigation experiments;

[0040] Example 6 is an investigation of the Ni loading amount in the catalyst;

[0041] Comparative examples 1-2 are nickel-based catalysts prepared using commercial carriers and commercially available noble metal-based catalysts, respectively;

[0042] The selectivity mentioned in the following examples and comparative examples is the selectivity of DINCH, and the conversion rate is the DINP conversion rate.

[0043] Example 1

[0044] The specific preparation steps of the hydrogenation catalyst are as follows:

[0045] (1) 90 mL of ethanol, 20 mL of deionized water and 4 mL of ammonia water (1.12 g) were uniformly mixed. Under the condition of continuous stirring, 4.46 mL (4 g) of tetrapropoxysilane was added, and then 0.66 mL of formaldehyde (0.53) and 0.5 g of resorcinol were added in sequence, and stirring was continued for 24 h. After centrifugation, deionized water washing, the solid product was collected and dried at 60°C for 24 h;

[0046] (2) The solid after crushing was calcined under a nitrogen atmosphere for 2 h at a temperature of 800°C, and then the calcined product was etched with a 2 mol / L sodium hydroxide solution at 95°C for 12 h to remove the silicon template. After washing and drying, a hollow mesoporous carbon sphere carrier was obtained;

[0047] (3) 9.6 g of nickel nitrate hexahydrate was weighed and completely dissolved in 20 mL of deionized water; 4.5 g of the carrier was put into the above impregnation solution, stirred for 3 h, and then refluxed at 110°C for 18 h in a reflux device. After the impregnation was completed, the catalyst precursor was dried in an oven at 70°C, and a catalyst precursor was obtained;

[0048] (4) Finally, the catalyst precursor was activated by calcination in a hydrogen atmosphere at a temperature of 150°C for 8 h, to obtain a diisononyl phthalate hydrogenation catalyst. In the diisononyl phthalate hydrogenation catalyst obtained in this embodiment, the Ni active ingredient accounts for 30% of the total mass (tested using ICP).

[0049] Example 2

[0050] Investigation of reaction temperature:

[0051] The catalytic properties of the catalyst were investigated using a tubular fixed bed reactor. The fixed bed reactor had a length of 1500 mm and an inner diameter of 32 mm. The upper and lower parts of the reactor were filled with quartz sand, and the catalyst prepared in Example 1 was placed in the middle. The catalyst loading was 200 mL. The reaction temperature, pressure, hydrogen and dihexyl phthalate feed amount were adjusted, and the catalytic reaction was carried out. The reaction material was cooled and sampled at regular intervals for analysis. Based on the area normalization method, the samples were qualitatively and quantitatively analyzed by liquid chromatography. The test instrument used was an American Agilent 1260 high performance liquid chromatograph. The chromatographic separation conditions were as follows: the chromatographic column was Agilent ZORBAX SB-C18 5 μm (4.6*150 mm), the mobile phase was HPLC methanol, the flow rate was 1.2 mL / min, the injection volume was 5 μL, the column temperature was 30°C, and the ultraviolet detection wavelength was 207 nm.

[0052] The effect of different reaction temperatures on the catalytic hydrogenation of dihexyl phthalate was investigated by changing only the reaction temperature. The other reaction conditions were as follows: pressure 6 MPa, space velocity 0.30 h -1The molar ratio of hydrogen to ester was 25:1, and the results are shown in Table 1 below.

[0053] Table 1

[0054] Temperature / °C Conversion / % Selectivity / % 140 88.0 89.1 150 99.2 99.0 160 99.2 99.3 170 99.0 98.6

[0055] The hydrogenation reaction of dihexyl naphthalene-1,2-dicarboxylate is an exothermic reaction, but appropriately increasing the temperature within a certain range is beneficial to the catalytic hydrogenation reaction. It can be found that when the temperature is increased to 160°C, the catalytic reaction effect reaches the optimum, and when the temperature is further increased to 170°C, the conversion rate and selectivity of hydrogenation decrease.

[0056] Example 3

[0057] Investigation of reaction pressure:

[0058] Compared with Example 2, the variable of this example is the reaction pressure, and the influence of different reaction pressures on the catalytic hydrogenation of dihexyl naphthalene-1,2-dicarboxylate is investigated. The reaction conditions are: temperature 160°C, space velocity 0.30h -1 , molar ratio of hydrogen to ester 25:1, and the results are shown in Table 2 below.

[0059] Table 2

[0060]

[0061]

[0062] It can be found from the above results that as the pressure increases, the catalytic effect improves, and when the pressure reaches 6 MPa, the catalytic effect reaches the optimum, and further increasing the pressure basically does not change the catalytic effect. This is because when the system pressure becomes large, the concentration of hydrogen in the reaction medium increases, and the amount of hydrogen adsorbed by the catalyst increases, thereby increasing the reaction rate of the system. When the pressure increases to a certain extent, the amount of hydrogen on the surface of the catalyst reaches saturation, and the conversion rate of the raw material is no longer affected, but too high pressure increases the cost of the reaction.

[0063] Example 4

[0064] Investigation of space velocity of raw material liquid:

[0065] Compared with Example 2, the variable of this example is the space velocity of the raw material liquid, and the influence of different space velocities of the raw material liquid on the catalytic hydrogenation of dihexyl naphthalene-1,2-dicarboxylate is investigated. The reaction conditions are: temperature 160°C, molar ratio of hydrogen to ester 25:1, pressure 6 MPa, and the results are shown in Table 3 below.

[0066] Table 3

[0067] airspeed / h -1 ]] Conversion / % Selectivity / % 0.20 98.7 99.1 0.30 99.2 99.3 0.40 98.9 95.1 0.45 91.6 90.5

[0068] From the above results, it can be found that with the increase of raw material liquid space velocity, the conversion rate of dihexyl naphthalene dicarboxylate first increases and then decreases. When the space velocity is low, the reaction heat is less, the reaction temperature rise is low, the internal temperature of the catalyst is low, the reaction conversion is incomplete, with the increase of the raw material liquid space velocity, the reaction heat increases, the reaction temperature rise is lower, the conversion rate rises. With the further increase of liquid space velocity, the contact time of material and catalyst is reduced, which leads to the decrease of reaction conversion rate and the appearance of hydrogenation intermediate product.

[0069] Example 5

[0070] Investigation of hydrogen-ester ratio:

[0071] Compared with Example 2, the variable of this embodiment is hydrogen-ester ratio, and the influence of different hydrogen-ester ratios on the catalytic hydrogenation of dihexyl naphthalene dicarboxylate is investigated. The reaction conditions are: temperature 160℃, space velocity 0.30h -1 , pressure 6MPa, and the results are shown in Table 4.

[0072] Table 4

[0073] Hydroester ratio Conversion / % Selectivity / % 10:1 99.1 99.0 15:1 98.9 99.2 25:1 99.2 99.3 30:1 99.1 99.0 35:1 99.0 99.2

[0074] From the above results, it can be found that when the hydrogen-ester ratio is 10:1, there is an intermediate in the reaction, and when the hydrogen-ester volume ratio is 25:1, the conversion rate of dihexyl naphthalene dicarboxylate and the selectivity of dihexyl cyclohexane dicarboxylate are higher.

[0075] Example 6

[0076] Investigation of Ni loading in hydrogenation catalyst:

[0077] Compared with Example 1, this embodiment appropriately increases or decreases the addition of nickel nitrate hexahydrate and the carrier, and the rest of the conditions remain unchanged. A series of catalysts with different nickel loadings are prepared, and finally various catalysts are prepared. The active components in the catalyst samples are quantitatively analyzed by inductively coupled plasma analysis (ICP). From the test results, the catalysts with Ni accounting for 15%, 40%, and 50% of the total mass of the catalyst are selected, and the catalyst with Ni accounting for 30% of the total mass of the catalyst in Example 1 is selected, a total of four catalysts, to investigate the influence of catalysts with different Ni loadings on the hydrogenation of dihexyl naphthalene dicarboxylate.

[0078] The catalysts with Ni contents of 15%, 30%, 40%, and 50% are subjected to dihexyl naphthalene dicarboxylate hydrogenation reaction to analyze the influence of catalysts with different Ni loadings on the hydrogenation of dihexyl naphthalene dicarboxylate. The conditions of the hydrogenation catalytic reaction are: temperature 160℃, pressure 6MPa, space velocity 0.30h -1 , hydrogen-ester molar ratio 25:1, and the rest of the conditions are as shown in Example 2. The results are shown in Table 5.

[0079] Table 5

[0080] Ru mass fraction / % Conversion / % Selectivity / % 15 95.6 97.1 30 99.2 99.3 40 99.1 99.0 50 97.2 95.1

[0081] The above results show that, within a certain range, increasing the loading of catalyst Ni can improve the hydrogenation catalytic activity of the catalyst, but excessive Ni loading can block the pores of the carrier, reduce the contact efficiency of the active substances of the catalyst with the reaction liquid, and further reduce the catalytic activity. Considering the cost of metal use, the catalyst proposed in the present application is relatively optimal when the Ni loading is 30%.

[0082] Comparative Example 1

[0083] Compared with Example 1, the difference of the present comparative example is that the commonly used commercial catalyst carrier mesoporous γ-Al2O3 is used to replace the hollow mesoporous carbon sphere carrier prepared in Example 1, and the same method is used to load Ni as a control material, which is denoted as γ-Al2O3-Ni catalyst.

[0084] Meanwhile, the prepared γ-Al2O3-Ni catalyst is subjected to hydrogenation catalytic reaction under the conditions of temperature 160℃, pressure 6MPa, space velocity 0.30h -1 , hydrogen ester molar ratio 25:1, and other steps are the same as those in Example 2.

[0085] Comparative Example 2

[0086] In the present example, a commercially available Ru-based catalyst: Al2O3 / 3%Ru is purchased as a catalyst for hydrogenation reaction, and the reaction conditions are temperature 160℃, pressure 6MPa, space velocity 0.30h -1 , hydrogen ester molar ratio 25:1, and other steps are the same as those in Example 2.

[0087] The Brunauer-Emmett-Teller (BET) specific surface area, pore volume and pore diameter of the carriers of Example 1 and Comparative Example 1 and the catalysts prepared after loading Ni are characterized by ASAP 2020V4.02 (V4.02J) physical adsorption instrument (Micromeritics, USA), and the results are shown in Table 7 below:

[0088] Table 7

[0089]

[0090] The specific surface area and pore diameter of the common commercially available carrier are small after loading a large amount of Ni, which is not conducive to the hydrogenation reaction. After 30% Ni is loaded on the hollow mesoporous carbon sphere carrier, the catalyst still has a large specific surface area and pore structure, still has the characteristics of mesoporous structure and super large specific surface area, can expose more catalytically active sites, and provides conditions for the full contact of the catalyst and the reaction liquid. The hollow mesoporous carbon sphere carrier has a large hydrogenation catalytic advantage for the nickel-based catalyst loaded thereon, specifically in that the raw material conversion rate and the selectivity of the target product are significantly improved. The catalyst has a catalytic effect comparable to that of the mainstream noble metal hydrogenation catalyst in the market, does not need to use noble metal, saves noble metal resources, and has market application potential.

[0091] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A method for preparing a hydrogenation catalyst for diisononyl phthalate, characterized in that, Includes the following steps: (1) Ammonia, tetrapropoxysilane, formaldehyde and resorcinol are added to a solvent to react, and the solid is collected, washed and dried to obtain the carrier precursor; the solvent is an alcohol-water solution; (2) The carrier precursor is calcined in an inert gas atmosphere, and then etched, cleaned and dried by alkaline solution to obtain carbon ball carrier; the carbon ball carrier is a hollow carbon ball with a mesoporous structure. (3) The nickel salt is loaded onto the carbon ball support by impregnation and then calcined in a hydrogen atmosphere to obtain the diisononyl phthalate hydrogenation catalyst.

2. The method for preparing the diisononyl phthalate hydrogenation catalyst as described in claim 1, characterized in that, In step (2), the calcination temperature is 700-900℃ and the calcination time is 1-5h.

3. The method for preparing the diisononyl phthalate hydrogenation catalyst as described in claim 1, characterized in that, In step (3), the roasting temperature is 150-350℃ and the roasting time is 5-12h.

4. The method for preparing the diisononyl phthalate hydrogenation catalyst as described in claim 1, characterized in that, Includes at least one of the following: In step (1), the reaction time is 12-48 hours; In step (1), the volume ratio of alcohol to water in the alcohol-water solution is (60-120):(10-30), and the alcohol includes ethanol; In step (1), the mass ratio of ammonia to tetrapropoxysilane is 1:(2-8). In step (1), the mass ratio of formaldehyde to tetrapropoxysilane is 1:(6-10). In step (1), the mass ratio of formaldehyde to resorcinol is 1:(0.8-2). In steps (1) and (2), the drying temperature is 60-80℃ and the drying time is 12-48h. In step (2), the etching temperature is 80-110℃ and the etching time is 12-18h; In step (2), the alkaline solution includes sodium hydroxide and potassium hydroxide solutions, and the concentration of the alkaline solution is 1-5 mol / L; In step (3), the immersion temperature is 90-120℃, the immersion time is 2-48h, and the immersion is carried out by reflux immersion. In step (3), during the impregnation process, the concentration of the nickel salt is 10-20 mol / L, and the mass ratio of the nickel salt to the carbon ball carrier is (0.5-5):

1.

5. A catalyst prepared by the method for preparing the diisononyl phthalate hydrogenation catalyst according to any one of claims 1-4.

6. The catalyst as described in claim 5, characterized in that, The carbon sphere carrier is a hollow carbon sphere with a mesoporous structure.

7. The catalyst as described in claim 5, characterized in that, The nickel content in the diisononyl phthalate hydrogenation catalyst is 15-50% by mass.

8. The application of the catalyst according to any one of claims 5-7, characterized in that, The catalyst according to any one of claims 5-7 is used as a catalyst for the hydrogenation reaction of diisononyl phthalate to prepare diisononyl cyclohexanedicarboxylate.

9. The application of the catalyst as described in claim 8, characterized in that, Includes at least one of the following: The temperature of the hydrogenation reaction is 140~170℃; The pressure of the hydrogenation reaction is 4~7 MPa; The liquid space velocity (LHSV) of the feedstock for the hydrogenation reaction is 0.1–0.45 h⁻¹. -1 .

10. The application of the catalyst as described in claim 8, characterized in that, Includes at least one of the following: The volume ratio of hydrogen gas to diisononyl phthalate in the hydrogenation reaction is (10~35):1; The hydrogenation reaction is carried out in a fixed-bed continuous hydrogenation reactor.

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