A catalyst for preparing cyclopentene by selective hydrogenation of cyclopentadiene and a preparation method and application thereof

Abstract

The application discloses a catalyst for preparing cyclopentene by selectively hydrogenating cyclopentadiene and a preparation method and application thereof. The catalyst is composed of an active component, a cocatalyst and a catalyst carrier. The catalyst preparation process is simple and easy to scale up. The prepared catalyst has the characteristics of high cyclopentadiene conversion rate, high cyclopentene selectivity, simple preparation process, low cost and long running period.

Description

TECHNICAL FIELD

[0001] The present application relates to a catalyst for preparing cyclopentene by hydrogenation of cyclopentadiene and its preparation method and application, belonging to the field of energy chemical industry, and particularly relates to a novel catalyst for preparing cyclopentene by hydrogenation of cyclopentadiene obtained by conversion of carbon five fraction byproduct of ethylene cracking device in petroleum chemical industry and its preparation method and application. BACKGROUND

[0002] Cyclopentene is a five-ring olefin containing one unsaturated double bond, which is active and easy to undergo oxidation, addition, polymerization and other reactions, and is an important organic chemical raw material, widely used in pharmaceutical industry, organic synthesis and synthetic rubber fields, and can be used to produce a variety of high-value fine chemicals, such as cyclopentanol, cyclopentanone, glutaraldehyde, glutaric acid, etc. At present, the main production process is to use cyclopentadiene obtained by conversion of carbon five fraction byproduct of ethylene cracking device as raw material, and to prepare cyclopentene by selective hydrogenation.

[0003] The research on selective hydrogenation of cyclopentadiene to prepare cyclopentene started in the 1960s and 1970s, and its preparation route includes: obtaining dicyclopentadiene by separation of carbon five fraction; then pyrolyzing and polymerizing the separated dicyclopentadiene to generate cyclopentadiene; and finally selectively hydrogenating the cyclopentadiene on Ni, Pd, Ru and other catalysts to obtain cyclopentene. In the reaction process, a small amount of cyclopentadiene will also polymerize to generate dicyclopentadiene, and its hydrogenation products dihydrodicyclopentadiene and tetrahydrodicyclopentadiene.

[0004] The key step of the route for producing cyclopentene from carbon five fraction is the selective hydrogenation of cyclopentadiene, that is, one of the two unsaturated double bonds of cyclopentadiene is saturated by hydrogenation, and the other is not hydrogenated. After the two double bonds of cyclopentadiene are completely saturated by hydrogenation, the obtained product is cyclopentane with lower value.

[0005] CN109745985B discloses a catalyst for preparing cyclopentene by hydrogenation of cyclopentadiene, which uses TiO2-Al2O3 composite oxide as a carrier, loads main active metal Ni and auxiliary active components Ag and Fe, is activated by H2 before use, and is passivated by an organic alkaline compound. CN110721681A discloses a Pd catalyst supported by a γ-Al2O3 carrier, which is prepared by spraying technology or impregnation method, uses metal promoters Sn, Mn, Ce or Zn to occupy active sites, inhibits excessive activity of single Pd particle clusters, and improves the selectivity of cyclopentene. CN1417179A discloses a method for preparing cyclopentene by catalytic hydrogenation of cyclopentadiene, which uses granular activated carbon as a carrier, uses palladium as an active component, and uses t-butyl alcohol as an auxiliary catalyst.

[0006] The currently disclosed supported catalyst has the characteristics of large carrier particles and high mechanical strength, and the product and the catalyst are easy to separate, which is suitable for use in a fixed bed reactor, but has the disadvantages of poor hydrogenation selectivity and large catalyst consumption. CN111085269A discloses a catalyst for preparing cyclopentene by hydrogenation of cyclopentadiene, which is prepared by aging reaction of organic metal compounds and / or metal complexes containing iron, cobalt, nickel and palladium, and alkyl metal compounds of aluminum or lithium. The catalyst prepared from the organic metal compound has the characteristics of small amount, high activity and good selectivity, which improves the above problems to a certain extent, but can only be applied to intermittent slurry bed hydrogenation mode, and is difficult to separate and recover after use.

[0007] In recent years, the scale of ethylene cracking device in China has been continuously expanding, and the yield of by-product C5 fraction has also increased substantially. At present, the cyclopentadiene product of C5 fraction conversion is mainly used for producing low-value materials such as unsaturated resin, while the production of high-value cyclopentene is limited by poor catalyst reaction activity, selectivity and service life, and there are few production enterprises with small scale, which increases the demand for high-activity, high-selectivity, long-life cyclopentadiene selective hydrogenation to cyclopentene catalyst with simple preparation process, low cost and wide applicability. SUMMARY

[0008] The application discloses a catalyst for preparing cyclopentene by selective hydrogenation of cyclopentadiene and a preparation method and application thereof. The catalyst preparation process is simple and easy to scale up. The catalyst has the characteristics of high cyclopentadiene conversion rate, high cyclopentene selectivity, low cost and long running period.

[0009] In one aspect, the application provides a preparation method of a catalyst for preparing cyclopentene by selective hydrogenation of cyclopentadiene, which comprises the following steps:

[0010] (S1): placing the carrier in an active component solution or an active component + promoter component solution for a certain period of time to obtain a catalyst precursor SA or SAP;

[0011] (S2): treating the catalyst precursor SA or SAP obtained in step (S1) by a heat treatment device 1 and a heat treatment device 2 to obtain a catalyst precursor SAD or SAPD;

[0012] The treatment of the catalyst precursor SAD is followed by step (S3);

[0013] The treatment of the catalyst precursor SAPD skips steps (S3) and (S4) and is followed by step (S5);

[0014] (S3): placing the catalyst precursor SAD obtained in step (S2) in a promoter component solution for a certain period of time to obtain a catalyst precursor SADP;

[0015] (S4): heat treating the catalyst precursor SADP obtained in step (S3) by heat processor 1 and heat processor 2 to obtain a catalyst precursor SADPD;

[0016] (S5): pretreating the catalyst precursor SADPD obtained in step (S4) or the catalyst precursor SAPD obtained in step (S2) to obtain a catalyst for selectively hydrogenating cyclopentadiene to prepare cyclopentene.

[0017] The catalyst for selectively hydrogenating cyclopentadiene to prepare cyclopentene comprises an active component, a promoter, and a catalyst carrier.

[0018] The catalyst carrier in step (S1) is one or more of TiO2, SiO2, Al2O3, ZrO2, activated carbon, and molecular sieve.

[0019] The active component in step (S1) is one or more of a nitrate, a sulfate, a chloride, and an organometallic salt of Pd, Pt, Ni, and Ru.

[0020] Preferably, the content of the active component in the catalyst is 0.005%-25% (based on the total mass of the catalyst, and calculated as active metal); wherein 0.005%-5% corresponds to the Pd, Pt, and Ru components (further preferably 0.005%-1%), and 1%-25% corresponds to the Ni component (further preferably 10%-25%).

[0021] The promoter in step (S1) is one or more of a nitrate, a chloride, a carbonate, a bicarbonate, and an organometallic salt of Fe, Pb, Na, Zn, K, Mn, Ag, and Ca.

[0022] Preferably, the content of the promoter in the catalyst is 0.005%-25% (based on the total mass of the catalyst, and calculated as oxide); preferably 0.05%-5%.

[0023] The solvent in the solution in step (S1) is one or more of water and an organic solvent; wherein the organic solvent is one or more of ethanol, methanol, benzene, toluene, xylene, and n-hexane.

[0024] In the method for preparing a catalyst for selectively hydrogenating cyclopentadiene to cyclopentene, the temperature of the solution in step (S1) is 20-85°C, preferably 20-50°C, and the residence time is 0.5-48h, preferably 6-36h.

[0025] In the method for preparing a catalyst for selectively hydrogenating cyclopentadiene to cyclopentene, the temperature of the heat treatment device 1 in step (S2) is 80-180°C, preferably 100-150°C, and the treatment time is 0.5-48h, preferably 12-36h; the temperature of the heat treatment device 2 is 200-650°C, preferably 250-550°C, and the treatment time is 0.5-24h, preferably 2-12h.

[0026] In the method for preparing a catalyst for selectively hydrogenating cyclopentadiene to cyclopentene, the promoter in step (S3) is one or more of nitrates, chlorides, carbonates, bicarbonates, and organometallic salts of Fe, Pb, Na, Zn, K, Mn, Ag, and Ca.

[0027] Preferably, the temperature of the promoter solution in step (S3) is 20-60°C, preferably 20-40°C, and the residence time is 3-24h, preferably 3-12h.

[0028] In the method for preparing a catalyst for selectively hydrogenating cyclopentadiene to cyclopentene, the temperature of the heat treatment device 1 in step (S4) is 120-150°C, and the treatment time is 18-36h; the temperature of the heat treatment device 2 is 250-500°C, and the treatment time is 0.5-12h.

[0029] In the method for preparing a catalyst for selectively hydrogenating cyclopentadiene to cyclopentene, the pretreatment in step (S5) is carried out in a pretreatment atmosphere, which is selected from H2 atmosphere, H2 mixed with H2S, CO, and NH3 atmosphere, H2 atmosphere followed by H2 mixed with H2S, CO, and NH3 atmosphere, or H2 mixed with H2S, CO, and NH3 atmosphere followed by H2 atmosphere. The mixed atmosphere can be a mixture of H2 with one of H2S, CO, and NH3, or a mixture of H2 with two or three of H2S, CO, and NH3. Preferably, the volume concentration of H2S, CO, and NH3 in the mixed atmosphere is 0.005%-5%, preferably 0.005%, 0.01%, 0.02%, 0.05%, 0.1%, 0.2%, 0.5%, 1%, 2%, 3%, 4%, or 5%. Preferably, the total volume concentration of H2S, CO, and NH3 in the mixed atmosphere is less than 5%.

[0030] In the method for preparing the catalyst for selectively hydrogenating cyclopentadiene to cyclopentene, the pretreatment temperature in step (S5) is 100-350°C (preferably 100-250°C), the pressure is 0.1-3 MPa (preferably 1-3 MPa), and the time is 0.5-24 h (preferably 3-24 h). Preferably, the temperature is controlled by programmed temperature rising, and the temperature rising rate is 0.1-5°C / min.

[0031] In the second aspect, the application provides the catalyst for selectively hydrogenating cyclopentadiene to cyclopentene prepared by the method.

[0032] In the third aspect, the application provides the application of the catalyst for selectively hydrogenating cyclopentadiene to cyclopentene. The application of the catalyst is characterized in that, under the assistance of auxiliary materials, the catalyst guides the selective hydrogenation reaction of cyclopentadiene and H2 to generate cyclopentene.

[0033] In the fourth aspect, the application provides a method for selectively hydrogenating cyclopentadiene and H2. The method comprises: under the assistance of auxiliary materials, the catalyst for selectively hydrogenating cyclopentadiene to cyclopentene guides the selective hydrogenation reaction of cyclopentadiene and H2 to generate cyclopentene.

[0034] In the application and the method, the reaction temperature is 30-250°C, and the reaction pressure is 0.1-3 MPa. Preferably, the reaction temperature is 40-150°C, and the reaction pressure is 0.1-1.5 MPa.

[0035] In the application and the method, the molar ratio of H2 to cyclopentadiene is 1:0.1-2, preferably 1:0.1-1, and more preferably 1:0.5-1.

[0036] In the application and the method, the auxiliary material is one or more of benzene, n-hexane, toluene, n-pentane, dimethylbenzene, and tetrahydrofuran. The mass ratio of cyclopentadiene to the auxiliary material is 1:1-30, and preferably 1:1-20.

[0037] In the application and the method, the hydrogenation reaction further comprises the assistance of auxiliary gas.

[0038] Preferably, the auxiliary gas is one or more of N2, Ar, and He. The volume ratio of the auxiliary gas to H2 is 0.1-8:1, and preferably 1-5:1.

[0039] In the application and the method, when the catalyst is pretreated without being treated in a mixed gas atmosphere, the hydrogenation reaction needs to be performed under the assistance of auxiliary materials and auxiliary gas.

[0040] In the application and method of the present application, the reactor for the selective hydrogenation reaction is optionally one or more of a combination of a fixed bed reactor, a batch slurry bed reactor, a continuous slurry bed reactor, a suspended bed reactor, and an expanded bed reactor.

[0041] Advantages of the present application

[0042] The preparation method of the present application is simple. By means of multi-stage heat treatment, the dispersion of active metals is improved. By introducing preferred reaction conditions such as mixed atmosphere pretreatment, auxiliary materials, and / or auxiliary gas, the catalytic efficiency can be maximized, the amount of catalyst used can be reduced, and the production cost of cyclopentene can be effectively controlled. The active sites can be moderate, the cyclopentene has high selectivity, the generation and accumulation of dimers and polymers are effectively inhibited, and the service life of the catalyst is effectively prolonged. The catalyst has wide applicability and can be used in various reactors and various hydrogenation processes. The preparation and use method of the catalyst is simple and convenient for industrial application. Examples

[0043] The technical solutions of the present application are further described below in combination with the following examples. However, it should be understood that the protection scope of the present application is not limited to these examples.

[0044] Example 1

[0045] 86.5 kg of nickel acetate tetrahydrate was dissolved in a mixed solvent of ethanol and n-hexane to obtain an active metal solution. 100 kg of SiO2-Al2O3 carrier was placed in the active metal solution, and after staying at 25℃ for 24 h, a catalyst precursor SA was obtained. The catalyst precursor SA was treated by a heat treatment device 1 at 120℃ for 18 h and by a heat treatment device 2 at 350℃ for 6 h to obtain a catalyst precursor SAD.

[0046] 24.86 kg of zinc nitrate hexahydrate and 8.95 kg of sodium nitrate were dissolved in water to obtain a catalyst promoter solution. The catalyst precursor SAD was placed in the catalyst promoter solution and stayed for 6 h to obtain a catalyst precursor SADP. The catalyst precursor SADP was treated by a heat treatment device 1 at 150℃ for 24 h and by a heat treatment device 2 at 550℃ for 12 h to obtain a catalyst precursor SADPD.

[0047] The catalyst precursor SADPD and benzene were added to a batch high-pressure reaction kettle, and after reduction at 1.5 MPa, 0.1℃ / min to 250℃, and H2 atmosphere for 6 h, the catalyst for the hydrogenation of cyclopentadiene to cyclopentene was obtained by pretreatment with H2 / H2S mixed gas with a volume concentration of 0.005% H2S for 6 h.

[0048] A mixture solution of cyclopentadiene and adjuvant was added into a batch autoclave, the mass ratio of cyclopentadiene to adjuvant was 1:1, and the adjuvant was dimethylbenzene. H2 was introduced, the molar ratio of H2 to cyclopentadiene was 1:0.8, the reaction pressure was 1.0 MPa, the reaction temperature was 60 ℃, and the reaction time was 2 h. The reaction was terminated, and the sample was analyzed to calculate the conversion rate of cyclopentadiene and the selectivity of cyclopentene. The results are shown in Table 1.

[0049] Example 2

[0050] 0.004 g of palladium nitrate and 0.007 g of lead nitrate were dissolved in water to obtain a mixed solution. 10 g of Al2O3 carrier was placed in the mixed solution, and after staying at 45 ℃ for 20 h, catalyst precursor SA was obtained. Catalyst precursor SA was treated by heat treatment device 1 at 80 ℃ for 24 h and by heat treatment device 2 at 350 ℃ for 5 h to obtain catalyst precursor SAD.

[0051] 0.07 g of potassium carbonate was dissolved in water to obtain a promoter solution. Catalyst precursor SAD was placed in the promoter solution and stayed at 35 ℃ for 6 h to obtain catalyst precursor SADP. Catalyst precursor C was treated by heat treatment device 1 at 100 ℃ for 24 h and by heat treatment device 2 at 500 ℃ for 8 h to obtain catalyst precursor SADPD.

[0052] Catalyst precursor SADPD was pressed into a tablet, crushed, and then loaded into a fixed bed reactor. The temperature was raised to 150 ℃ at a rate of 0.1 ℃ / min, and the catalyst was pretreated in an H2 atmosphere at 3.0 MPa for 6 h to obtain a catalyst for the hydrogenation of cyclopentadiene to cyclopentene.

[0053] A mixture solution of cyclopentadiene and adjuvant was pumped into a fixed bed reactor, the mass ratio of cyclopentadiene to adjuvant was 1:20, and the adjuvant was n-hexane. H2 (the molar ratio of H2 to cyclopentadiene was 1:0.5), auxiliary gas N2 (the volume ratio of N2 to H2 was 5:1), and the reaction pressure were introduced, and the reaction temperature was 130 ℃. The reaction process was sampled and analyzed to calculate the conversion rate of cyclopentadiene and the selectivity of cyclopentene. The results are shown in Table 1.

[0054] Example 3

[0055] 51 kg of platinum chloride, 14 kg of iron nitrate, and 17 kg of silver nitrate were dissolved in water to obtain a mixed solution. 1000 kg of Al2O3-ZrO2 carrier was placed in the mixed solution, and after staying at 80 ℃ for 12 h, catalyst precursor SAP was obtained. Catalyst precursor SAP was treated by heat treatment device 1 at 150 ℃ for 16 h and by heat treatment device 2 at 250 ℃ for 16 h to obtain catalyst precursor SAPD.

[0056] The catalyst precursor SAPD was loaded into an expanded bed reactor, and heated to 100°C at a rate of 0.1°C / min, and then pretreated in a H2 / NH3 mixed gas atmosphere with a NH3 volume concentration of 1% at 3.0 MPa for 24 h to obtain a catalyst for the hydrogenation of cyclopentadiene to cyclopentene.

[0057] The cyclopentadiene was mixed with a solvent, and the mass ratio of cyclopentadiene to solvent was 1:5. The mixed solution was fed into an expanded bed reactor, and hydrogenation was carried out by feeding in H2 (the molar ratio of H2 to cyclopentadiene was 1:0.9), auxiliary gas Ar (the volume ratio of Ar to H2 was 3:1), and the reaction pressure was 2.0 MPa and the reaction temperature was 90°C. During the reaction, samples were taken for analysis, and the conversion of cyclopentadiene and the selectivity of cyclopentene were calculated. The results are shown in Table 1.

[0058] Example 4

[0059] 0.05 g of ruthenium carbonyl chloride was dissolved in ethanol to obtain an active metal solution. 100 g of TiO2 carrier was placed in the active solution, and after staying at 50°C for 2 h, a catalyst precursor SA was obtained. The catalyst precursor SA was treated by heat treatment device 1 at 110°C for 12 h and by heat treatment device 2 at 450°C for 3 h to obtain a catalyst precursor SAD.

[0060] 0.13 g of zinc nitrate and 0.016 g of manganese sulfate were dissolved in water to obtain a promoter solution. The catalyst precursor SAD was placed in the promoter solution, and after staying at 50°C for 18 h, a catalyst precursor SADP was obtained. The catalyst precursor SADP was treated by heat treatment device 1 at 50°C for 24 h and by heat treatment device 2 at 300°C for 6 h to obtain a catalyst precursor SADPD.

[0061] The catalyst precursor SADPD was loaded into a continuous slurry / suspension bed reactor, and heated to 200°C at a rate of 5°C / min, and then pretreated in a H2 mixed gas atmosphere with a total volume concentration of 5% of NH3 and CO (the volume ratio was 1:1) at 1.20 MPa for 9 h to obtain a catalyst for the hydrogenation of cyclopentadiene to cyclopentene.

[0062] A mixed solution of cyclopentadiene and a solvent (the solvent was a mixed solution of benzene / dimethylbenzene, and the mass ratio of cyclopentadiene, benzene, and dimethylbenzene was 1:1:2) was fed into a continuous slurry bed reactor, and hydrogenation was carried out by feeding in H2 (the molar ratio of H2 to cyclopentadiene was 1:1), auxiliary gas N2 (the volume ratio of N2 to H2 was 3:1), and the reaction pressure was 1.8.0 MPa and the reaction temperature was 50°C. During the reaction, samples were taken for analysis, and the conversion of cyclopentadiene and the selectivity of cyclopentene were calculated. The results are shown in Table 1.

[0063] Example 5

[0064] 7g of palladium chloride was dissolved in water to obtain an active metal solution. 5kg of activated carbon carrier was placed in the active solution, and after staying at 75℃ for 22h, catalyst precursor SA was obtained. Catalyst precursor SA was treated by heat treatment device 1 at 150℃ for 12h to obtain catalyst precursor SAD.

[0065] 7g of silver nitrate and 2g of calcium acetate were dissolved in water to obtain a promoter solution. Catalyst precursor SAD was placed in the promoter solution, and after staying at 60℃ for 16h, catalyst precursor SADP was obtained. Catalyst precursor SADP was treated by heat treatment device 1 at 120℃ for 24h and by heat treatment device 2 at 350℃ for 6h to obtain catalyst precursor SADPD.

[0066] Catalyst precursor SADPD was loaded into a fluidized bed reactor, and after heating at 0.1℃ / min to 120℃, it was pretreated at 2.5MPa in a H2 atmosphere for 3h to obtain a catalyst for hydrogenation of cyclopentadiene to cyclopentene.

[0067] Cyclopentadiene and adjuvant (the adjuvant was a mixed solution of tetrahydrofuran / toluene, and the mass ratio of cyclopentadiene, tetrahydrofuran and toluene was 1:1:10) were fed into the fluidized bed reactor, and hydrogen (the amount-of-substance ratio of H2 to cyclopentadiene was 1:0.9), auxiliary gas N2 (the volume ratio of N2 to H2 was 2:1) and reaction pressure 0.5MPa were introduced, and the reaction temperature was 90℃. During the reaction, samples were taken for analysis, and the conversion rate of cyclopentadiene and the selectivity of cyclopentene were calculated. The results are shown in Table 1.

[0068] Comparative Example 1

[0069] 86.5kg of nickel acetate tetrahydrate was dissolved in a mixed solvent of ethanol and n-hexane to obtain an active metal solution. 100kg of SiO2-Al2O3 carrier was placed in the active metal solution, and after staying at 25℃ for 24h, catalyst precursor SA was obtained. Catalyst precursor SA was treated by heat treatment device 1 at 120℃ for 18h and by heat treatment device 2 at 350℃ for 6h to obtain catalyst precursor SAD.

[0070] 24.86kg of zinc nitrate hexahydrate and 8.95kg of sodium nitrate were dissolved in water to obtain a promoter solution. Catalyst precursor SAD was placed in the promoter solution and stayed for 6h to obtain catalyst precursor SADP. Catalyst precursor C was treated by heat treatment device 1 at 150℃ for 24h and by heat treatment device 2 at 550℃ for 12h to obtain catalyst precursor SADPD.

[0071] The catalyst precursor SADPD and benzene were added into a batch high-pressure reactor, and the catalyst for preparing cyclopentene by hydrogenation of cyclopentadiene was obtained after pretreatment at 1.5 MPa, 0.1 ℃ / min to 250 ℃, H2 atmosphere for 6 h.

[0072] A mixed solution of cyclopentadiene and auxiliary material dimethylbenzene was added into a batch high-pressure reactor, the mass ratio of cyclopentadiene to auxiliary material was 1:1, H2 was introduced, the molar ratio of H2 to cyclopentadiene was 1:0.75, the reaction pressure was 1.0 MPa, the reaction temperature was 60 ℃, the reaction time was 2 h, the reaction was terminated, and sampling analysis was performed, the conversion rate of cyclopentadiene and the selectivity of cyclopentene were calculated, and the results are shown in Table 1.

[0073] Comparative Example 2

[0074] 0.004 g of palladium nitrate and 0.007 g of lead nitrate were dissolved in water to obtain a mixed solution. 10 g of Al2O3 carrier was placed in the above mixed solution, and after staying at 45 ℃ for 20 h, catalyst precursor SA was obtained. The catalyst precursor SA was treated by heat treatment device 1 at 80 ℃ for 24 h and by heat treatment device 2 at 350 ℃ for 5 h to obtain catalyst precursor SAD.

[0075] Potassium carbonate 0.07 g was dissolved in water to obtain a catalyst promoter solution, and the catalyst precursor SAD was placed in the catalyst promoter solution and stayed for 6 h to obtain catalyst precursor SADP. The catalyst precursor SADP was treated by heat treatment device 1 at 100 ℃ for 24 h and by heat treatment device 2 at 500 ℃ for 8 h to obtain catalyst precursor SADPD.

[0076] The catalyst precursor SADPD was pressed into tablets, crushed, and then loaded into a fixed bed reactor, and the temperature was raised to 150 ℃ at 0.1 ℃ / min. The catalyst for preparing cyclopentene by hydrogenation of cyclopentadiene was obtained after pretreatment at 3.0 MPa, H2 atmosphere for 6 h.

[0077] A mixed solution of cyclopentadiene and auxiliary material (the mass ratio of cyclopentadiene to auxiliary material was 1:20, and the auxiliary material was n-hexane) was pumped into a fixed bed reactor, H2 was introduced (the molar ratio of H2 to cyclopentadiene was 1:0.8), the reaction pressure was 0.5 MPa, and the reaction temperature was 130 ℃. Sampling analysis was performed during the reaction, and the conversion rate of cyclopentadiene and the selectivity of cyclopentene were calculated, and the results are shown in Table 1.

[0078] Comparative Example 3

[0079] 7 g of palladium chloride was dissolved in water to obtain an active metal solution. 5 kg of activated carbon carrier was placed in the above active solution, and after staying at 75 ℃ for 22 h, catalyst precursor SAP was obtained. The catalyst precursor SAP was treated by heat treatment device 1 at 150 ℃ for 12 h to obtain catalyst precursor SAPD.

[0080] The catalyst precursor SAPD is loaded into a boiling bed reactor, and pre-processed under H2 atmosphere at 2.5 MPa for 3 h at a temperature rising rate of 0.1 ℃ / min to 120 ℃ to obtain a catalyst for hydrogenation of cyclopentadiene to cyclopentene.

[0081] A mixed solution of cyclopentadiene and adjuvant tetrahydrofuran / toluene (mass ratio of cyclopentadiene to adjuvant is 1:1:10) is fed into the boiling bed reactor, and hydrogenation is carried out under the conditions of H2 (molar ratio of H2 to cyclopentadiene is 1:0.6), auxiliary gas N2 (volume ratio of N2 to H2 is 2:1), reaction pressure 0.5 MPa, and reaction temperature 90 ℃. During the reaction, sampling analysis is carried out, and the conversion rate of cyclopentadiene and the selectivity of cyclopentene are calculated. The results are shown in Table 1.

[0082] Table 1. Results of selective catalytic hydrogenation of cyclopentadiene in examples and comparative examples

[0083]

[0084]

[0085] As can be seen from the above examples and their reaction performances, the active metal and the promoter of the cyclopentadiene hydrogenation to cyclopentene catalyst provided by the present application are uniformly dispersed on the surface of the carrier, which significantly improves the catalytic efficiency of the active metal, and has a high cyclopentadiene conversion rate and a high cyclopentene selectivity. As can be seen from the reaction results of the above comparative examples, the cyclopentadiene hydrogenation to cyclopentene catalyst provided by the present application eliminates the excessively high active center on the surface of the catalyst by adding a promoter and introducing a mixed gas atmosphere for pre-treatment or an auxiliary gas, thereby avoiding excessive hydrogenation and improving the selectivity of cyclopentene. The preparation method of the cyclopentadiene hydrogenation to cyclopentene catalyst provided by the present application is simple in process, low in cost, and convenient for industrial application. The method for cyclopentadiene hydrogenation to cyclopentene provided by the present application has wide applicability and can be applied to various reactors and various hydrogenation processes.

[0086] It should be noted that the examples in the present application and the features in the examples can be combined with each other without conflict. The specific examples are further descriptions of the present application, but not as a limitation of the present application. Some non-essential improvements and adjustments made by the person skilled in the art according to the content of the present application still belong to the protection scope of the present application.

Claims

1. A method for preparing a catalyst for the selective hydrogenation of cyclopentadiene to cyclopentene, the method comprising the following steps: (S1): The support is placed in the solution of the active component or the solution of the active component and the co-catalyst component for a certain period of time to obtain the catalyst precursor SA or SAP; (S2): The catalyst precursor SA or SAP obtained in step (S1) is processed by heat processor 1 and heat processor 2 to obtain catalyst precursor SAD or SAPD; the temperature of heat processor 1 is 80-180℃ and the temperature of heat processor 2 is 200-650℃. Treatment of the catalyst precursor SAD, proceeding to step (S3). For the treatment of the catalyst precursor SAPD, skip steps (S3) and (S4) and proceed to step (S5). (S3): Place the catalyst precursor SAD obtained in step (S2) in the co-catalyst component solution for a certain period of time to obtain the catalyst precursor SADP; (S4): The catalyst precursor SADP obtained in step (S3) is processed by heat processor 1 and heat processor 2 to obtain catalyst precursor SADPD; the temperature of heat processor 1 is 120-150℃ and the temperature of heat processor 2 is 250-500℃. (S5): Pretreatment of the catalyst precursor SADPD obtained in step (S4) or the catalyst precursor SAPD obtained in step (S2) yields a catalyst for the selective hydrogenation of cyclopentadiene to cyclopentene. The catalyst support mentioned in step (S1) is one or more of TiO2, SiO2, Al2O3, ZrO2, activated carbon, and molecular sieve; the active component mentioned in step (S1) is one or more of nitrates, sulfates, chlorides, and organometallic salts of Pd, Pt, Ni, and Ru; the co-catalyst component mentioned in step (S1) is one or more of nitrates, chlorides, carbonates, bicarbonates, and organometallic salts of Fe, Pb, Na, Zn, K, Mn, Ag, and Ca; the co-catalyst component mentioned in step (S3) is one or more of nitrates, chlorides, carbonates, bicarbonates, and organometallic salts of Fe, Pb, Na, Zn, K, Mn, Ag, and Ca. The pretreatment in step (S5) is carried out in a pretreatment atmosphere at a temperature of 100-350°C. The pretreatment atmosphere is selected as a mixture of H2, H2S, and NH3; or H2 atmosphere is used first, followed by a mixture of H2, H2S, and NH3. The volume concentrations of H2S and NH3 in the mixture are 0.005%-5% respectively.

2. The production method according to claim 1, characterized by, The content of active components in the catalyst, based on the total mass of the catalyst and calculated as active metals, is 0.005%-25%; the content of co-catalyst in the catalyst, based on the total mass of the catalyst and calculated as oxides, is 0.005%-25%.

3. A catalyst for the selective hydrogenation of cyclopentadiene to prepare cyclopentene, prepared by the method described in any one of claims 1-2.

4. A process for the selective hydrogenation of cyclopentadiene with H2 comprising: The catalyst for the selective hydrogenation of cyclopentadiene to cyclopentene according to claim 3, with the assistance of an excipient, guides the selective hydrogenation reaction of cyclopentadiene with H2 to generate cyclopentene; the excipient is one or more of benzene, n-hexane, toluene, n-pentane, xylene, and tetrahydrofuran; the mass ratio of cyclopentadiene to excipient is 1:1-30.

5. The method of claim 4, wherein, The mass ratio of cyclopentadiene to excipients is 1:1-20.

6. The method of claim 4, wherein, The hydrogenation reaction also includes the assistance of an auxiliary gas; the auxiliary gas is one or more of N2, Ar, and He; the volume ratio of the auxiliary gas to H2 is 0.1-8:

1.

7. The method of claim 6, wherein, The volume ratio of auxiliary gas to H2 is 1-5:

1.

8. A process for the selective hydrogenation of cyclopentadiene with H2 comprising: A catalyst for the selective hydrogenation of cyclopentadiene to cyclopentene, with the assistance of excipients, guides the selective hydrogenation reaction of cyclopentadiene with H2 to generate cyclopentene. The preparation method of the catalyst for the selective hydrogenation of cyclopentadiene to cyclopentene includes the following steps: (S1): The support is placed in the solution of the active component or the solution of the active component and the co-catalyst component for a certain period of time to obtain the catalyst precursor SA or SAP; (S2): The catalyst precursor SA or SAP obtained in step (S1) is processed by heat processor 1 and heat processor 2 to obtain catalyst precursor SAD or SAPD; the temperature of heat processor 1 is 80-180℃ and the temperature of heat processor 2 is 200-650℃. Treatment of the catalyst precursor SAD, proceeding to step (S3). For the treatment of the catalyst precursor SAPD, skip steps (S3) and (S4) and proceed to step (S5). (S3): Place the catalyst precursor SAD obtained in step (S2) in the co-catalyst component solution for a certain period of time to obtain the catalyst precursor SADP; (S4): The catalyst precursor SADP obtained in step (S3) is processed by heat processor 1 and heat processor 2 to obtain catalyst precursor SADPD; the temperature of heat processor 1 is 120-150℃ and the temperature of heat processor 2 is 250-500℃. (S5): Pretreatment of the catalyst precursor SADPD obtained in step (S4) or the catalyst precursor SAPD obtained in step (S2) yields a catalyst for the selective hydrogenation of cyclopentadiene to cyclopentene. The catalyst support mentioned in step (S1) is one or more of TiO2, SiO2, Al2O3, ZrO2, activated carbon, and molecular sieve; the active component mentioned in step (S1) is one or more of nitrates, sulfates, chlorides, and organometallic salts of Pd, Pt, Ni, and Ru; the co-catalyst component mentioned in step (S1) is one or more of nitrates, chlorides, carbonates, bicarbonates, and organometallic salts of Fe, Pb, Na, Zn, K, Mn, Ag, and Ca; the co-catalyst component mentioned in step (S3) is one or more of nitrates, chlorides, carbonates, bicarbonates, and organometallic salts of Fe, Pb, Na, Zn, K, Mn, Ag, and Ca. The pretreatment in step (S5) is carried out in a pretreatment atmosphere at a temperature of 100-350°C. The pretreatment atmosphere is selected as H2 atmosphere. The excipient is one or more of benzene, n-hexane, toluene, n-pentane, xylene, and tetrahydrofuran; the mass ratio of cyclopentadiene to the excipient is 1:1-30; The hydrogenation reaction also includes the assistance of an auxiliary gas; the auxiliary gas is one or more of N2, Ar, and He; the volume ratio of the auxiliary gas to H2 is 0.1-8:

1.

9. The method according to claim 8, characterized in that, The mass ratio of cyclopentadiene to excipients is 1:1-20.

10. The method according to claim 8, characterized in that, The volume ratio of auxiliary gas to H2 is 1-5:1.

Images