Cheap high-stability hydroquinone hydrogenation catalyst and preparation method thereof

Abstract

The invention discloses a low-cost high-stability hydroquinone hydrogenation catalyst and a preparation method thereof. The catalyst comprises the following components: an active component, a carrier, a sintering aid, a pore forming agent and a lubricant, the active component is any one of Ni, Co, Zn, Fe and Cu; the carrier is SiC; the sintering aid is any one or more of Al2O3 (aluminum oxide), SiO2 (silicon dioxide), Y2O3 (yttrium oxide) and silicon-aluminum-based clay; the pore-forming agent is any one or more of bamboo charcoal, silica sol, starch and carboxymethyl cellulose; and the lubricant is glycerol. The invention also provides a preparation method of the low-cost high-stability hydroquinone hydrogenation catalyst. According to the catalyst and the preparation method thereof provided by the invention, the prepared silicon carbide loaded multi-metal catalyst has good thermal conductivity, good chemical stability and excellent mechanical properties, and the problems of carbonization and sintering caused by loss of active components of the catalyst and slow heat transfer of the catalyst are greatly reduced.

Description

Technical Field

[0001] The present invention relates to a cheap and highly stable hydroquinone hydrogenation catalyst for use in the chemical industry and a synthesis method thereof, and in particular to a cheap and highly stable hydroquinone hydrogenation catalyst and a preparation method thereof. Background Art

[0002] 1,4-cyclohexanediol is an important organic intermediate and plays a vital role in the fields of medicine and material monomers. In the field of medicine, it is an indispensable component of some drugs. For example, HMGCoA reductase is a key component in the synthesis of cholesterol, which is inseparable from 1,4-cyclohexanediol as an important intermediate. In addition, 1,4-cyclohexanediol is also an important intermediate for some antibiotics, such as sulfamethoxazole. At the same time, due to its special stereo conformation, 1,4-cyclohexanediol promotes the skin permeability of some drugs, such as metronidazole, and provides strong support for the synthesis and optimization of drugs, effectively improving the efficacy and pertinence of drugs. In the field of new material development, spectrally pure 1,4-cyclohexanediol also plays a pivotal role. It is one of the core raw materials for the successful synthesis of cutting-edge innovative materials such as liquid crystal materials, organic electrical materials, and biocontroller markers. Taking organic electrical materials as an example, the purity and chemical properties of 1,4-cyclohexanediol directly determine the performance and application range of organic electrical materials.

[0003] The synthesis method of 1,4-cyclohexanediol generally uses hydroquinone as raw material and adopts the method of catalytic benzene ring hydrogenation. At present, most catalysts are used in autoclave reactors. The autoclave reaction system has problems such as poor operation continuity and cumbersome separation operation. Applying the hydroquinone hydrogenation process to a continuously operated fixed bed system is a key means to simplify the production process and promote industrialization. On the other hand, given that Ru-based catalysts have poor selectivity and Ru species are expensive, and Raney Ni catalysts generally require the addition of alkaline species to cause serious environmental pollution, the development and design of cheap Ni-based hydrogenation catalysts for hydroquinone to 1,4-cyclohexanediol is of great significance and is another key issue.

[0004] The synthesis of 1,4-cyclohexanediol is generally carried out by hydrogenation reaction in a reactor or fixed bed reactor using hydroquinone as raw material. The cost of the reactor reaction is high because of the expensive catalyst, complicated separation process and lack of continuity.

[0005] In the fixed bed reactor hydrogenation, CN113292396A uses γ-Al2O3 and inorganic carbon as carriers, loaded with transition metals as catalysts; CN115487821B uses inorganic oxides as carriers, loaded with multimetals as catalysts; CN113292397B uses composite oxides as carriers, double transition metals as catalysts, all of which can achieve high conversion rates and high selectivity in the synthesis of 1,4-cyclohexanediol. However, the alumina carrier has active chemical properties and poor thermal conductivity, and the activated carbon carrier has poor antioxidant properties and low mechanical strength. After a long reaction, the structure is prone to deformation, and the active components are seriously lost, which greatly affects the stability and regeneration activity of the catalyst. Summary of the invention

[0006] The purpose of the present invention is to provide a catalyst for the hydrogenation of hydroquinone to synthesize 1,4-cyclohexanediol and a preparation method thereof, which can reduce the loss of active components of the catalyst and the carbonization and sintering problems caused by slow heat transfer of the catalyst, thereby providing a possibility for expanding production.

[0007] In order to achieve the above-mentioned object, the present invention provides a low-cost and high-stability hydroquinone hydrogenation catalyst, wherein the components of the catalyst include: an active component, a carrier, a sintering aid, a pore-forming agent, and a lubricant; the active component is any one of Ni, Co, Zn, Fe, and Cu; the carrier is SiC; the sintering aid is any one or more of Al2O3, SiO2, Y2O3, and silica-aluminum-based clay; the pore-forming agent is any one or more of bamboo charcoal and silica sol, starch, and carboxymethyl cellulose; and the lubricant is glycerol.

[0008] The above-mentioned cheap and high-stability hydroquinone hydrogenation catalyst, wherein the carrier is SiC, and the models include: W10 with d50 of 9.50 μm, W14 with d50 of 14.05 μm, W20 with d50 of 19.85 μm, W28 with d50 of 28.12 μm, W40 with d50 of 39.01 μm, F220 with d50 of 57.35 μm, F240 with d50 of 48.08 μm, and F1200 with d50 of 3.82 μm.

[0009] The above-mentioned cheap and highly stable hydroquinone hydrogenation catalyst, wherein the components of the catalyst, by mass percentage, include: 1%-10% active component, 60%-85% carrier, 5%-20% sintering aid, 1%-20% pore former, and 1%-8% lubricant.

[0010] The above-mentioned cheap and highly stable hydroquinone hydrogenation catalyst, wherein the components of the catalyst, by mass percentage, include: 2%-5% active component, 75%-80% carrier, 8%-13% sintering aid, 9%-12% pore former, and 1%-2% lubricant.

[0011] The above-mentioned cheap and highly stable hydroquinone hydrogenation catalyst, wherein the sintering aid is obtained by uniformly mixing Al2O3 and Y2O3 in a mass ratio of 44:56.

[0012] The present invention also provides a method for preparing the above-mentioned cheap and highly stable hydroquinone hydrogenation catalyst, wherein the method comprises: step 1, mixing a carrier, a sintering aid, and a pore-forming agent uniformly; step 2, adding a mixed solution of a lubricant and water to the mixture obtained in step 1, extruding after treatment, and then heating and drying; step 3, adding a compound containing an active component to water, mixing uniformly, and obtaining a mixed solution; step 4, adding the composite carrier obtained in step 2 to the mixed solution obtained in step 3, impregnating it, and then heating and evaporating to remove water, and then drying and calcining it; step 5, reducing the catalyst obtained in step 4 before use; and step 6, using the catalyst obtained in step 5 to carry out a hydrogenation reaction of hydroquinone.

[0013] The above-mentioned method for preparing the inexpensive and highly stable hydroquinone hydrogenation catalyst, wherein, in the step 2, a mixture of glycerol and deionized water is slowly added dropwise to a mixture of a carrier, a sintering aid and a pore-forming agent, and then the mixture is successively subjected to the processes of mud kneading, aging and extrusion, and then the obtained product is dried at a temperature of 80°C for 12 hours, and then degreased and sintered to obtain a uniform SiC composite carrier.

[0014] The above-mentioned method for preparing the inexpensive and highly stable hydroquinone hydrogenation catalyst, wherein, in the step 4, a SiC composite carrier is added to a mixed solution consisting of a compound containing an active component and deionized water, fully impregnated and stirred for 2 hours, then rotary evaporated at a temperature of 60°C, then dried at a temperature of 110°C for 12 hours, and then calcined at a temperature of 500°C for 6 hours to obtain a catalyst.

[0015] The preparation method of the above-mentioned cheap and high-stability hydroquinone hydrogenation catalyst, wherein, in the step 5, the reduction conditions of the catalyst are pressure 1-2MPa, reduction temperature 200-500°C, heating rate 10°C / min, reduction time 4-6h, the reducing gas used is H2, and the gas space velocity is 2500h -1 .

[0016] The preparation method of the above-mentioned cheap and high-stability hydroquinone hydrogenation catalyst, wherein, in the step 6, the reduced catalyst is used to carry out the reaction of hydroquinone hydrogenation to synthesize 1,4-cyclohexanediol, the catalyst loading is 5-10ml, the reaction temperature is 140-180°C, the reaction pressure is 2-4MPa, the mass concentration of hydroquinone is 1%-15%, the solvent is any one of ethanol, isopropanol, and n-butanol, the molar ratio of hydrogen to hydroquinone is 5-20:1, and the weight hourly space velocity of hydroquinone is 0.05-1h -1 .

[0017] The low-cost and high-stability hydroquinone hydrogenation catalyst and the preparation method thereof provided by the present invention have the following advantages:

[0018] The present invention provides a multi-metal catalyst loaded with SiC as a main carrier and a preparation method thereof, which is used in the reaction of hydrogenating hydroquinone to synthesize 1,4-cyclohexanediol. The prepared silicon carbide-loaded multi-metal catalyst has good thermal conductivity, good chemical stability and excellent mechanical properties, greatly reduces the loss of active components of the catalyst and the carbonization and sintering problems caused by slow heat transfer of the catalyst, can improve product quality and yield, reduce production costs, and reduce impact on the environment, and has important practical significance and broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The graph is a graph showing the change in hydroquinone conversion rate over time in the embodiments and comparative examples of the present invention. DETAILED DESCRIPTION

[0020] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0021] The invention provides a low-cost and high-stability hydroquinone hydrogenation catalyst, and the components of the catalyst include: an active component, a carrier, a sintering aid, a pore-forming agent, and a lubricant; the active component is any one of Ni, Co, Zn, Fe, and Cu; the carrier is SiC; the sintering aid is any one or more of Al2O3, SiO2, Y2O3, and silica-aluminum-based clay; the pore-forming agent is any one or more of bamboo charcoal and silica sol, starch, and carboxymethyl cellulose; and the lubricant is glycerol.

[0022] Preferably, the carrier is SiC, and the models include: W10 with d50 (median diameter or median particle size) of 9.50 μm, W14 with d50 of 14.05 μm, W20 with d50 of 19.85 μm, W28 with d50 of 28.12 μm, W40 with d50 of 39.01 μm, F220 with d50 of 57.35 μm, F240 with d50 of 48.08 μm, and F1200 with d50 of 3.82 μm.

[0023] The components of the catalyst include, by mass percentage, 1%-10% of active components, 60%-85% of carriers, 5%-20% of sintering aids, 1%-20% of pore formers, and 1%-8% of lubricants.

[0024] More preferably, the components of the catalyst include, by mass percentage: 2%-5% active component, 75%-80% carrier, 8%-13% sintering aid, 9%-12% pore former, and 1%-2% lubricant.

[0025] The sintering aid is prepared by uniformly mixing Al2O3 and Y2O3 (yttrium trioxide) in a mass ratio of 44:56.

[0026] The present invention also provides a preparation method of the cheap and high-stability hydroquinone hydrogenation catalyst, which comprises: step 1, uniformly mixing a carrier, a sintering aid and a pore-forming agent; step 2, adding a mixed solution of a lubricant and water to the mixture obtained in step 1, extruding after treatment, and then heating and drying; step 3, adding a compound containing an active component to water, mixing evenly to obtain a mixed solution; step 4, adding the composite carrier obtained in step 2 to the mixed solution obtained in step 3, impregnating it, heating and evaporating to remove water, and then drying and calcining it; step 5, reducing the catalyst obtained in step 4 before use; and step 6, using the catalyst obtained in step 5 to carry out a hydrogenation reaction of hydroquinone.

[0027] Preferably, step 2 is to slowly add a mixture of glycerol and deionized water to the mixture of the carrier, sintering aid and pore-forming agent, and then sequentially go through the processes of mud kneading, aging and extrusion, and then dry the obtained product at a temperature of 80°C for 12 hours, and then degrease and sinter to obtain a uniform SiC composite carrier.

[0028] Clay kneading is to stir the solid-liquid mixture evenly to make mud blocks or mud slurry. Aging is to place the kneaded mud in an environment that is not light-transmitting, not ventilated, and has a certain temperature and humidity to allow the mud to ferment naturally.

[0029] Degreasing is the process of putting the prepared mixed powder into a mold, and after pressing and forming, it enters a degreasing furnace, where the mixed powder in the mold is heated to a high temperature so that the organic matter in the powder decomposes and evaporates. This step is called degreasing.

[0030] Sintering is the process of heating the powder in the mold to a high temperature after degreasing, so that the particles in the powder combine with each other to form a dense solid.

[0031] Step 4 is to add the SiC composite carrier to the mixed solution of the compound containing the active component and deionized water, fully impregnate and stir for 2 hours, then rotary evaporate to dryness at 60°C, then dry at 110°C for 12 hours, and then calcine at 500°C for 6 hours to obtain the catalyst.

[0032] In step 5, the reduction conditions of the catalyst are pressure 1-2MPa, reduction temperature 200-500°C, heating rate 10°C / min, reduction time 4-6h, the reducing gas used is H2, and the gas space velocity is 2500h -1 .

[0033] In step 6, the reduced catalyst is used to carry out a reaction of hydrogenating hydroquinone to synthesize 1,4-cyclohexanediol, the catalyst loading is 5-10 ml, the reaction temperature is 140-180° C., the reaction pressure is 2-4 MPa, the mass concentration of hydroquinone is 1%-15%, the solvent is any one of ethanol, isopropanol, and n-butanol, the molar ratio of hydrogen to hydroquinone is 5-20:1, and the weight hourly space velocity of hydroquinone is 0.05-1h -1 .

[0034] The inexpensive and highly stable hydroquinone hydrogenation catalyst and the preparation method thereof provided by the present invention are further described below in conjunction with the embodiments.

[0035] It should be noted that these embodiments are merely illustrative and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, conventional experimental conditions or conditions recommended in the manufacturer's instructions are used. Where the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially, and substitutes with the same or similar effects can be used for equivalent replacement.

[0036] Example 1

[0037] Weigh 40g of SiC powder of model W10 (d50: 9.50μm), 2.2g of Al2O3, 2.8g of Y2O3, and 6g of carboxymethyl cellulose, mix them evenly in a kneader, and then slowly add a mixture of 20g of deionized water and 4g of glycerol. After kneading, aging, and extrusion, the product is dried at 80°C for 12h, and then degreased and sintered to obtain a uniform SiC composite carrier.

[0038] Weigh 0.99 g of Ni(NO3)2·6H2O, dissolve it in 10 g of deionized water to obtain a Ni(NO3)2 solution, then weigh 10 g of a SiC composite carrier, immerse it in the Ni(NO3)2 solution, stir for 2 h, then rotary evaporate to dryness at 60°C, then dry at 110°C for 12 h, and finally calcine at 500°C for 6 h.

[0039] Example 2

[0040] Weigh 40g of SiC powder of model W14 (d50: 14.05μm), 2.2g of Al2O3, 2.8g of Y2O3, and 6g of carboxymethyl cellulose, mix them evenly in a kneader, and then slowly add a mixture of 20g of deionized water and 4g of glycerol. After kneading, aging, and extrusion, the resulting product is dried at 80°C for 12h, and then degreased and sintered to obtain a uniform SiC composite carrier.

[0041] Weigh 0.99 g of Ni(NO3)2·6H2O, dissolve it in 10 g of deionized water to obtain a Ni(NO3)2 solution, then weigh 10 g of a SiC composite carrier, immerse it in the Ni(NO3)2 solution, stir for 2 h, then rotary evaporate to dryness at 60°C, then dry at 110°C for 12 h, and finally calcine at 500°C for 6 h.

[0042] Example 3

[0043] Weigh 40g of SiC powder of model W20 (d50: 19.85μm), 2.2g of Al2O3, 2.8g of Y2O3, and 6g of carboxymethyl cellulose, mix them evenly in a kneader, and then slowly add a mixture of 20g of deionized water and 4g of glycerol. After kneading, aging, and extrusion, the resulting product is dried at 80°C for 12h, and then degreased and sintered to obtain a uniform SiC composite carrier.

[0044] Weigh 0.99 g of Ni(NO3)2·6H2O, dissolve it in 10 g of deionized water to obtain a Ni(NO3)2 solution, then weigh 10 g of a SiC composite carrier, immerse it in the Ni(NO3)2 solution, stir for 2 h, then rotary evaporate to dryness at 60°C, then dry at 110°C for 12 h, and finally calcine at 500°C for 6 h.

[0045] Example 4

[0046] Weigh 40g of SiC powder of model W28 (d50: 28.12μm), 2.2g of Al2O3, 2.8g of Y2O3, and 6g of carboxymethyl cellulose, mix them evenly in a kneader, and then slowly add a mixture of 20g of deionized water and 4g of glycerol. After kneading, aging, and extrusion, the product is dried at 80°C for 12h, and then degreased and sintered to obtain a uniform SiC composite carrier.

[0047] Weigh 0.99 g of Ni(NO3)2·6H2O, dissolve it in 10 g of deionized water to obtain a Ni(NO3)2 solution, then weigh 10 g of a SiC composite carrier, immerse it in the Ni(NO3)2 solution, stir for 2 h, then rotary evaporate to dryness at 60°C, then dry at 110°C for 12 h, and finally calcine at 500°C for 6 h.

[0048] Example 5

[0049] Weigh 40g of SiC powder of model W40 (d50: 39.01μm), 2.2g of Al2O3, 2.8g of Y2O3, and 6g of carboxymethyl cellulose, mix them evenly in a kneader, and then slowly add a mixture of 20g of deionized water and 4g of glycerol. After kneading, aging, and extrusion, the resulting product is dried at 80°C for 12h, and then degreased and sintered to obtain a uniform SiC composite carrier.

[0050] Weigh 0.99 g of Ni(NO3)2·6H2O, dissolve it in 10 g of deionized water to obtain a Ni(NO3)2 solution, then weigh 10 g of a SiC composite carrier, immerse it in the Ni(NO3)2 solution, stir for 2 h, then rotary evaporate to dryness at 60°C, then dry at 110°C for 12 h, and finally calcine at 500°C for 6 h.

[0051] Example 6

[0052] Weigh 40g of SiC powder of model F220 (d50: 57.35μm), 2.2g of Al2O3, 2.8g of Y2O3, and 6g of carboxymethyl cellulose, mix them evenly in a kneader, and then slowly add a mixture of 20g of deionized water and 4g of glycerol. After kneading, aging, and extrusion, the product is dried at 80°C for 12h, and then degreased and sintered to obtain a uniform SiC composite carrier.

[0053] Weigh 0.99 g of Ni(NO3)2·6H2O, dissolve it in 10 g of deionized water to obtain a Ni(NO3)2 solution, then weigh 10 g of a SiC composite carrier, immerse it in the Ni(NO3)2 solution, stir for 2 h, then rotary evaporate to dryness at 60°C, then dry at 110°C for 12 h, and finally calcine at 500°C for 6 h.

[0054] Example 7

[0055] Weigh 40g of SiC powder of model F240 (d50: 48.08μm), 2.2g of Al2O3, 2.8g of Y2O3, and 6g of carboxymethyl cellulose, mix them evenly in a kneader, and then slowly add a mixture of 20g of deionized water and 4g of glycerol. After kneading, aging, and extrusion, the product is dried at 80°C for 12h, and then degreased and sintered to obtain a uniform SiC composite carrier.

[0056] Weigh 0.99 g of Ni(NO3)2·6H2O, dissolve it in 10 g of deionized water to obtain a Ni(NO3)2 solution, then weigh 10 g of a SiC composite carrier, immerse it in the Ni(NO3)2 solution, stir for 2 h, then rotary evaporate to dryness at 60°C, then dry at 110°C for 12 h, and finally calcine at 500°C for 6 h.

[0057] Example 8

[0058] Weigh 40g of SiC powder of model F1200 (d50: 3.82μm), 2.2g of SiO2, 2.8g of silica-alumina clay, and 6g of carboxymethyl cellulose, mix them evenly in a kneader, and then slowly add a mixture of 20g of deionized water and 4g of glycerol. After kneading, aging, and extrusion, the resulting product is dried at 80°C for 12h, and then degreased and sintered to obtain a uniform SiC composite carrier.

[0059] Weigh 0.99 g of Ni(NO3)2·6H2O, dissolve it in 10 g of deionized water to obtain a Ni(NO3)2 solution, then weigh 10 g of a SiC composite carrier, immerse it in the Ni(NO3)2 solution, stir for 2 h, then rotary evaporate to dryness at 60°C, then dry at 110°C for 12 h, and finally calcine at 500°C for 6 h.

[0060] Example 9

[0061] Weigh 40g of SiC powder of model W14 (d50: 14.05μm), 2.2g of Al2O3, 2.8g of Y2O3, and 6g of carboxymethyl cellulose, mix them evenly in a kneader, and then slowly add a mixture of 20g of deionized water and 4g of glycerol. After kneading, aging, and extrusion, the resulting product is dried at 80°C for 12h, and then degreased and sintered to obtain a uniform SiC composite carrier.

[0062] Weigh 0.82g of Co(NO3)2·6H2O and dissolve it in 10g of deionized water to obtain a Co(NO3)2 solution. Then weigh 10g of the SiC composite carrier and immerse it in the Co(NO3)2 solution. Stir for 2h, then rotary evaporate at 60°C, then dry at 110°C for 12h, and finally calcine at 500°C for 6h.

[0063] Example 10

[0064] Weigh 40g of SiC powder of model W14 (d50: 14.05μm), 2.2g of Al2O3, 2.8g of Y2O3, and 6g of carboxymethyl cellulose, mix them evenly in a kneader, and then slowly add a mixture of 20g of deionized water and 4g of glycerol. After kneading, aging, and extrusion, the resulting product is dried at 80°C for 12h, and then degreased and sintered to obtain a uniform SiC composite carrier.

[0065] Weigh 0.88 g of Zn(NO3)2·6H2O and dissolve it in 10 g of deionized water to obtain a Zn(NO3)2 solution. Then weigh 10 g of SiC composite carrier and immerse it in the Zn(NO3)2 solution. Stir for 2 h, then rotary evaporate at 60°C, then dry at 110°C for 12 h, and finally calcine at 500°C for 6 h.

[0066] Embodiment 11

[0067] Weigh 40g of SiC powder of model W14 (d50: 14.05μm), 2.2g of Al2O3, 2.8g of Y2O3, and 6g of carboxymethyl cellulose, mix them evenly in a kneader, and then slowly add a mixture of 20g of deionized water and 4g of glycerol. After kneading, aging, and extrusion, the resulting product is dried at 80°C for 12h, and then degreased and sintered to obtain a uniform SiC composite carrier.

[0068] Weigh 1.45g of Fe(NO3)3·9H2O and dissolve it in 10g of deionized water to obtain a Fe(NO3)3 solution. Then weigh 10g of SiC composite support and immerse it in the Fe(NO3)3 solution. Stir for 2h, then rotary evaporate at 60℃, then dry at 110℃ for 12h, and finally calcine at 500℃ for 6h.

[0069] Example 12

[0070] Weigh 40g of SiC powder of model W14 (d50: 14.05μm), 2.2g of Al2O3, 2.8g of Y2O3, and 6g of carboxymethyl cellulose, mix them evenly in a kneader, and then slowly add a mixture of 20g of deionized water and 4g of glycerol. After kneading, aging, and extrusion, the resulting product is dried at 80°C for 12h, and then degreased and sintered to obtain a uniform SiC composite carrier.

[0071] Weigh 0.79 g of Cu(NO3)2·3H2O and dissolve it in 10 g of deionized water to obtain a Cu(NO3)2 solution. Then weigh 10 g of a SiC composite carrier and immerse it in the Cu(NO3)2 solution. Stir for 2 h, then rotary evaporate to dryness at 60°C, then dry at 110°C for 12 h, and finally calcine at 500°C for 6 h.

[0072] Embodiment 13

[0073] Weigh 40g of SiC powder of model W14 (d50: 14.05μm), 2.2g of Al2O3, 2.8g of Y2O3, 2g of bamboo charcoal and 4g of silica sol, mix them evenly in a kneader, and then slowly add a mixture of 20g of deionized water and 4g of glycerol. After kneading, aging and extrusion, the product is dried at 80°C for 12h, and then degreased and sintered to obtain a uniform SiC composite carrier.

[0074] Weigh 0.99 g of Ni(NO3)2·6H2O, dissolve it in 10 g of deionized water to obtain a Ni(NO3)2 solution, then weigh 10 g of a SiC composite carrier, immerse it in the Ni(NO3)2 solution, stir for 2 h, then rotary evaporate to dryness at 60°C, then dry at 110°C for 12 h, and finally calcine at 500°C for 6 h.

[0075] Embodiment 14

[0076] Weigh 40g of SiC powder of model W14 (d50: 14.05μm), 2.2g of Al2O3, 2.8g of Y2O3, and 6g of starch, mix them evenly in a kneader, and then slowly add a mixture of 20g of deionized water and 4g of glycerol. After kneading, aging, and extrusion, the product is dried at 80°C for 12h, and then degreased and sintered to obtain a uniform SiC composite carrier.

[0077] Weigh 0.99 g of Ni(NO3)2·6H2O, dissolve it in 10 g of deionized water to obtain a Ni(NO3)2 solution, then weigh 10 g of a SiC composite carrier, immerse it in the Ni(NO3)2 solution, stir for 2 h, then rotary evaporate to dryness at 60°C, then dry at 110°C for 12 h, and finally calcine at 500°C for 6 h.

[0078] Comparative Example 1

[0079] Weigh 40g of γ-Al2O3, 0.64g of sesbania powder, and 0.52g of citric acid, mix them evenly, then weigh 1.1g of HNO3 with a mass concentration of 8%, slowly drop it into the mixture, extrude it, and then dry it at 80℃ for 12h, and then calcine it at 550℃ for 6h to make an Al2O3 composite carrier. Weigh 2.53g of Ni(NO3)2·6H2O, dissolve it in 20g of deionized water, then weigh 10g of the Al2O3 composite carrier and immerse it in the Ni(NO3)2 solution, stir it for 2h, then rotary evaporate it at 60℃ until there is no liquid, then dry it at 110℃ for 12h, and finally calcine it at 500℃ for 4h.

[0080] Comparative Example 2

[0081] Weigh 40g of ZMS-5 molecular sieve, 0.64g of sesbania powder, and 2.6g of citric acid, mix them evenly, then weigh 1.1g of HNO3 with a mass concentration of 8%, slowly drop it into the mixture, extrude it, then dry it at 80℃ for 12h, and then calcine it at 550℃ for 6h to make a molecular sieve composite carrier. Weigh 2.53g of Ni(NO3)2·6H2O, dissolve it in 20g of deionized water, then weigh 10g of the molecular sieve composite carrier and immerse it in the Ni(NO3)2 solution, stir it for 2h, then rotary evaporate it at 60℃ until there is no liquid, then dry it at 110℃ for 12h, and finally calcine it at 500℃ for 4h.

[0082] The catalysts prepared in Examples 1 to 14 and Comparative Examples 1 to 2 were used in the hydrogenation reaction of hydroquinone.

[0083] The catalyst is reduced before use. The preferred reduction conditions are: pressure 1-2MPa, reduction temperature 200-500°C, heating rate 10°C / min, reduction time 4-6h, H2 as the reducing gas, gas space velocity 2500h -1 .

[0084] More preferably, the reduction conditions are: pressure 1 MPa, reduction temperature 500°C, heating rate 10°C / min, reduction time 6h, reducing gas is H2, gas hourly space velocity, i.e., gas space velocity GHSV = 2500h-1 .

[0085] Gas Hourly Space Velocity (GHSV), also known as volumetric space velocity, is a parameter that characterizes catalyst performance, especially in catalytic reactions. It is defined as the volume flowing through the catalyst surface area per unit time.

[0086] The reduced catalyst is used to carry out the reaction of hydrogenating hydroquinone to synthesize 1,4-cyclohexanediol.

[0087] Preferably, the loading amount of the catalyst is 5-10 ml, the reaction temperature is 140-180° C., the reaction pressure is 2-4 MPa, the mass concentration of hydroquinone is 1%-15%, the solvent is any one of ethanol, isopropanol, and n-butanol, the molar ratio of hydrogen to hydroquinone is 5-20:1, and the weight hourly space velocity of hydroquinone is 0.05-1h -1 .

[0088] More preferably, the reaction conditions are: catalyst loading 5 ml, reaction temperature 160°C, reaction pressure 2 MPa, mass concentration of hydroquinone 5%, solvent ethanol, molar ratio of H2 to hydroquinone 15:1, weight hourly space velocity of hydroquinone 0.5 h -1 .

[0089] The liquid products were analyzed by gas chromatography using an Agilent Poroshell 120 chiral column and a FID detector, and the chromatograms were processed by area percentage normalization.

[0090] After a period of reaction, the catalyst is regenerated: when the conversion rate of hydroquinone is lower than 80%, the reactor and the catalyst bed are cleaned with 10 ml / h of ethanol, and the temperature is maintained at 40°C and the pressure is maintained at 0.1 MPa. When the ethanol content in the liquid product is greater than 99.9%, the regeneration is stopped, and then the above hydroquinone hydrogenation reaction is repeated.

[0091] The obtained hydroquinone hydrogenation reaction results are shown in Table 1 below.

[0092] Table 1. Results of the reaction of using the catalysts of various examples and comparative examples for hydrogenation of hydroquinone to synthesize 1,4-cyclohexanediol.

[0093]

[0094]

[0095] The curves of the hydroquinone conversion rate changes with time in Examples 1 to 3 and Comparative Examples 1 to 2 are as follows: Figure 1 shown.

[0096] The invention provides a low-cost and high-stability hydroquinone hydrogenation catalyst and a preparation method thereof. A multi-metal catalyst with SiC as a main carrier is prepared and applied in the reaction of hydroquinone hydrogenation to synthesize 1,4-cyclohexanediol, which greatly reduces the loss of active components of the catalyst and the carbonization and sintering problems caused by slow heat transfer of the catalyst, has high reaction efficiency and yield, can improve product quality and yield, reduce production costs, reduce environmental impact, and greatly improve the practical applicability of the production process.

[0097] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A low-cost and highly stable hydroquinone hydrogenation catalyst, characterized in that: The components of the catalyst include: active components, carriers, sintering aids, pore formers, and lubricants; The active component is any one of Ni, Co, Zn, Fe and Cu; The carrier is SiC; The sintering aid is any one or more of Al2O3, SiO2, Y2O3 and silicon-aluminum-based clay; The pore-forming agent is any one or more of bamboo charcoal, silica sol, starch, and carboxymethyl cellulose; The lubricant is glycerol.

2. The low-cost, high-stability hydroquinone hydrogenation catalyst according to claim 1, characterized in that: The carrier is SiC, and the models include: W10 with d50 of 9.50 μm, W14 with d50 of 14.05 μm, W20 with d50 of 19.85 μm, W28 with d50 of 28.12 μm, W40 with d50 of 39.01 μm, F220 with d50 of 57.35 μm, F240 with d50 of 48.08 μm, and F1200 with d50 of 3.82 μm.

3. The low-cost and highly stable hydroquinone hydrogenation catalyst according to claim 1, characterized in that: The components of the catalyst include, by mass percentage: 1%-10% of active component, 60%-85% of carrier, 5%-20% of sintering aid, 1%-20% of pore former, and 1%-8% of lubricant.

4. The low-cost and highly stable hydroquinone hydrogenation catalyst according to claim 3, characterized in that: The components of the catalyst include, by mass percentage, 2%-5% of active component, 75%-80% of carrier, 8%-13% of sintering aid, 9%-12% of pore former and 1%-2% of lubricant.

5. The low-cost and highly stable hydroquinone hydrogenation catalyst according to claim 4, characterized in that: The sintering aid is obtained by uniformly mixing Al2O3 and Y2O3 in a mass ratio of 44:

56.

6. A method for preparing a low-cost and highly stable hydroquinone hydrogenation catalyst as claimed in any one of claims 1 to 5, characterized in that: The method comprises: Step 1, uniformly mix the carrier, sintering aid and pore-forming agent; Step 2: adding a mixed solution of lubricant and water to the mixture obtained in step 1, extruding after treatment, and then heating and drying; Step 3, adding the compound containing the active ingredient into water, mixing evenly, to obtain a mixed solution; Step 4, adding the composite carrier obtained in step 2 to the mixed solution obtained in step 3 for impregnation, then heating and evaporating to remove water, and then drying and calcining; Step 5, reducing the catalyst obtained in step 4 before use; Step 6, using the catalyst obtained in step 5, to carry out hydrogenation reaction of hydroquinone.

7. The method for preparing a low-cost and highly stable hydroquinone hydrogenation catalyst as claimed in claim 6, characterized in that: In the step 2, a mixture of glycerol and deionized water is slowly added to the mixture of the carrier, sintering aid and pore-forming agent, and then the mixture is subjected to the processes of slurry kneading, aging and extrusion, and then the obtained product is dried at 80°C for 12 hours, and then degreased and sintered to obtain a uniform SiC composite carrier.

8. The method for preparing a low-cost and highly stable hydroquinone hydrogenation catalyst as claimed in claim 6, characterized in that: In the step 4, a SiC composite carrier is added to a mixed solution of a compound containing an active component and deionized water, which is fully impregnated and stirred for 2 hours, then rotary evaporated at 60°C, dried at 110°C for 12 hours, and then calcined at 500°C for 6 hours to obtain a catalyst.

9. The method for preparing a low-cost and highly stable hydroquinone hydrogenation catalyst according to claim 6, characterized in that: In step 5, the reduction conditions of the catalyst are as follows: pressure 1-2MPa, reduction temperature 200-500°C, heating rate 10°C / min, reduction time 4-6h, reduction gas H2, gas space velocity 2500h -1 .

10. The method for preparing a low-cost and highly stable hydroquinone hydrogenation catalyst according to claim 6, characterized in that: In step 6, the reduced catalyst is used to carry out a reaction of hydrogenating hydroquinone to synthesize 1,4-cyclohexanediol, the catalyst loading is 5-10 ml, the reaction temperature is 140-180° C., the reaction pressure is 2-4 MPa, the mass concentration of hydroquinone is 1%-15%, the solvent is any one of ethanol, isopropanol, and n-butanol, the molar ratio of hydrogen to hydroquinone is 5-20:1, and the weight hourly space velocity of hydroquinone is 0.05-1h -1 .

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