Method for preparing adamantane

Abstract

A continuous method for producing adamantane, comprising: 1) supplying a liquid feed stream containing end-tetrahydrodicyclopentadiene; and 2) passing the liquid feed stream sequentially through a first reaction zone filled with a hydrogenation protecting agent and a second reaction zone filled with an isomerization catalyst to carry out a hydroisomerization reaction to obtain the adamantane. The method has a simple process operation, has no contamination, can realize long-term continuous preparation of adamantane, and has prospects for practical industrial applications.

Description

Detailed Description of the Invention

[0001] 〔Technical Field〕 The present application relates to the field of hydrocarbon preparation, particularly to a method for producing adamantane.

[0002] 〔Background〕 Adamantane (ADH) is a highly symmetric polycyclic cage-type hydrocarbon compound with the molecular formula of C 10 H 16 and has characteristics such as high density, good thermal stability, and liposolubility. The hydrogen atoms on its ring can undergo substitution reactions and oxidation reactions such as halogenation reaction, nitration reaction, and sulfonation reaction. Adamantane has a very wide range of applications in fields such as the synthesis of pharmaceutical intermediates, the development of new materials, and the preparation of lubricating oils and high-density liquid fuels.

[0003] Currently, the methods for synthesizing adamantane mainly include the aluminum trichloride method, the molecular sieve method, the superacid method, the ionic liquid method, etc. In these methods, adamantane is mainly prepared by taking endo-tetrahydrodicyclopentadiene (endo-THDCPD) as the starting material and performing an isomerization reaction. The main products of the substances involved in the reaction process are adamantane and its isomer exo-tetrahydrodicyclopentadiene (exo-THDCPD). The specific reaction process is shown in the following figure.

[0004]

Chemical Formula

[0005] The reaction mechanism for preparing adamantane is a carbonium ion reaction catalyzed by an acid. An acid is necessary as a catalyst. During the reaction process, an olefin intermediate may be generated. The olefin intermediate is likely to generate excessive tar by-products under the action of a strong acid catalyst, forming a competitive reaction with the formation of adamantane. This leads to a low selectivity of adamantane and significant material waste. However, if the acid is not strong enough or the reaction conditions are too mild, the formation of adamantane cannot be promoted, and the product mainly contains slightly isomerized products, i.e., exo-tetrahydrodicyclopentadiene. The selectivity of adamantane is also low.

[0006] Among the above methods, the aluminum trichloride method has the characteristics of high conversion rate and high selectivity. The conversion rate can reach over 95%, the selectivity can reach 50%, and the residue is mainly tar products. The aluminum trichloride method is currently used for industrial production of adamantane. However, this method is a batch production method of adamantane by regarding the reaction kettle as a reactor, and there are problems such as high toxicity, complex post-treatment, impossibility of recycling the catalyst, and a large amount of tar generation in this method. Therefore, the technology for producing adamantane has low total production volume, high cost, and serious pollution, and cannot meet the future development trend of green and low-carbon chemical industry. The paper "Synthesis of adamantane on commercially available zeolitic catalysts, Applied Catalysis A: General, 2000, 127 - 132." studies the preparation of adamantane by isomerization of end-THDCPD with different molecular sieve catalysts. When using Hβ as the catalyst, the yield of adamantane is 15.9%, but a large amount of tar is generated at a yield of 60% in the process, and it has no possibility for industrial application. The paper "Synthesis of adamantane on PW / USY composite catalyst, high-grade chemical engineering report, 2007, 127 - 132" discloses that a PW / USY catalyst supported with 10% phosphotungstic acid is used for the isomerization of end-THDCPD to adamantane, and a yield of 28.3% is obtained. However, this reaction is carried out in a reaction kettle. After each reaction, carbon deposits are formed on the surface of the PW / USY catalyst. High-temperature calcination regeneration is required. Its regeneration is frequent and does not bring continuous production capacity. Patent CN1398245A discloses a catalyst for producing adamantane, and the catalyst is prepared with Y-type molecular sieve by an ion exchange process for supporting Group VIII metals. The continuous reaction occurs in a stainless steel reaction tube.When the conversion rate of propylene norbornane (i.e., endo-THDCPD) reaches 95.2% at 350 °C, the selectivity of adamantane is 12.8%. There is still room for further improvement in the conversion rate and selectivity.

[0007] The continuous production of adamantane has not been realized in the literature reported in the prior art. In particular, the problem that the catalyst is prone to coking and deactivation has not been solved, and there is still a need to develop a suitable catalyst and the corresponding method.

[0008] 〔Disclosure of the Invention〕 The object of the present application is to provide a method for producing adamantane that enables the production of adamantane with a high conversion rate and high selectivity from endo-tetrahydrodicyclopentadiene as a raw material and is suitable for the continuous long-term stable production of adamantane.

[0009] In order to achieve the above object, in one aspect, the present application provides a continuous method for producing adamantane, comprising: 1) a step of supplying a liquid feed stream containing endo-tetrahydrodicyclopentadiene; 2) passing the liquid feed stream through a first reaction zone filled with a hydrogenation protective agent and a second reaction zone filled with an isomerization catalyst in sequence, and performing a hydroisomerization reaction to obtain adamantane; wherein the reaction temperature in the first reaction zone is 120 - 300 °C, the reaction temperature in the second reaction zone is 181 - 300 °C, the hydrogenation protective agent is a supported metal hydrogenation catalyst, and the isomerization catalyst is a metal-modified molecular sieve catalyst.

[0010] Preferably, step 1) further comprises a step of pretreating the liquid feed stream containing endo-tetrahydrodicyclopentadiene with an adsorbent.

[0011] In another aspect, the present application is a method for producing adamantane, comprising: a step of bringing a liquid feed stream containing end-tetrahydrodicyclopentadiene into contact with an isomerization catalyst in a hydrogen atmosphere to carry out an isomerization reaction; wherein the isomerization catalyst has a specific surface area of 450 to 900 m 2 / g, a pore volume of 0.25 to 0.5 cm 3 / g, a mesopore volume of 0.02 to 0.10 cm 3 / g, an amount of strong acid of 150 to 850 μmol / g, a reaction temperature of 181 to 300 °C, and a reaction pressure of 0.1 to 3.0 MPa, and is a metal-modified molecular sieve catalyst. A method is provided.

[0012] On the one hand, in the present application, the end-tetrahydrodicyclopentadiene reaction raw material can pass through a first reaction zone filled with a hydrogenation protecting agent and a second reaction zone filled with an isomerization catalyst in sequence, and preferably, after adsorption pretreatment, a hydroisomerization reaction is carried out. This can greatly improve the service life of the isomerization catalyst and the stability of the process, and achieve green and continuous stable production of adamantane. Without generating tar, the conversion rate can reach 99%, and the selectivity of the target product adamantane can reach 15.9%. Its atom utilization rate is high. The method can achieve continuous operation for more than 500 hours and has prospects for industrial application.

[0013] In addition, on the other hand, in the present application, the hydroisomerization reaction of endo - tetrahydrodicyclopentadiene is carried out in the presence of a metal / molecular sieve - supported dual - function catalyst having specific characteristics. As a result, the activity and stability of the catalyst in the reaction process can be improved, the coking and deactivation of the catalyst can be significantly suppressed, the reaction conversion rate and selectivity are further improved, and the method is suitable for the continuous long - term stable production of adamantane.

[0014] Additional features and advantages of the present application are set forth in the following detailed description.

[0015] 〔Detailed Description〕 Embodiments of the present application are described in detail below. It should be understood that the embodiments herein are used only to illustrate and describe the present application without any limitation to the present application.

[0016] It should be understood that any specific value disclosed herein (including the endpoints of the range of values) is not limited to the exact value of that value, but also includes all possible values close to the exact value, for example, all values within ±5% of the exact value. Also, for the disclosed range of values, any combination between the endpoints of the range, between the endpoints of the range and a specific point within the range, and between specific points can result in one or more new ranges of values, and such new ranges of values should also be considered as specifically disclosed herein.

[0017] Unless otherwise defined, the terms used herein have the same meaning as commonly understood by those skilled in the art. If a term is defined herein and its definition is different from the definition commonly understood in the art, the definition herein shall prevail.

[0018] In this application, unless otherwise specified, anything not mentioned is directly applicable to what is known in the art without any modification, except for what is explicitly described. Further, any embodiment described in this document may be freely combined with one or more other embodiments described in this document, and the technical solutions or ideas formed thereby shall be regarded as part of the original disclosure or original record of this application, and shall not be regarded as new content not disclosed or expected in this document, unless those skilled in the art consider the combination to be clearly unreasonable.

[0019] In this application, unless otherwise specified, pressure is given as gauge pressure.

[0020] In this application, unless otherwise specified, the metal content of the hydrogenation protecting agent and the isomerization catalyst is given as metal elements.

[0021] In this application, the term "volume ratio of hydrogen to liquid" refers to the volume ratio of hydrogen gas to liquid materials in the reaction system, and the unit is Nm 3 / m 3 .

[0022] In this application, the specific surface area of the catalyst and the pore volume (including the mesopore volume) are measured using the nitrogen isothermal physical adsorption and desorption process (BET).

[0023] In this application, the total acid amount and strong acid amount of the catalyst are measured by the pyridine absorption infrared spectroscopy process (Py-IR).

[0024] All patents and non-patent documents referred to in this specification, including but not limited to textbooks and magazine articles, are incorporated by reference in their entirety.

[0025] As described above, in the first aspect, this application is a continuous method for producing adamantane, 1) Supplying a liquid feed stream containing end - tetrahydrodicyclopentadiene; 2) Passing the liquid feed stream sequentially through a first reaction zone filled with a hydrogenation protecting agent and a second reaction zone filled with an isomerization catalyst to carry out a hydroisomerization reaction to obtain adamantane; comprising, the reaction temperature in the first reaction zone is 120 - 300 °C, preferably 151 - 250 °C, more preferably 171 - 220 °C, the reaction temperature in the second reaction zone is 181 - 300 °C, preferably 200 - 260 °C, the hydrogenation protecting agent is a metal - supported hydrogenation catalyst, the isomerization catalyst is a metal - modified molecular sieve catalyst, and provides a method.

[0026] According to the present application, there are no particular requirements for end - tetrahydrodicyclopentadiene as a starting material, and it may be prepared by various methods disclosed in the prior art or commercially available.

[0027] In a preferred embodiment, the liquid feed stream comprises end - tetrahydrodicyclopentadiene and a reaction solvent selected from hydrocarbons or halogenated hydrocarbons having a boiling point of 40 - 300 °C such as cyclohexane, methylcyclohexane, dichloromethane, exo - tetrahydrodicyclopentadiene, etc., the hydrocarbon or halogenated hydrocarbon solvent is preferably selected from C6 - C10 hydrocarbons, more preferably selected from cyclohexane, methylcyclohexane, exo - tetrahydrodicyclopentadiene, or combinations thereof. Preferably, the mass concentration of end - tetrahydrodicyclopentadiene in the feed stream is 10 - 80%, more preferably 30 - 60%.

[0028] In a preferred embodiment, step 1) further includes a step of pretreating the liquid feed stream containing endo-tetrahydrodicyclopentadiene with an adsorbent. Without being particularly limited by theory, the inventors of the present application have found that the removal of water, sulfides, nitrides, oxygen-containing compounds, etc. from the liquid feed stream by adsorption pretreatment can significantly improve the stability of the reaction system and facilitate the continuous long-term stable production of adamantane.

[0029] In a more preferred embodiment, the adsorbent is selected from activated clay, NaY molecular sieve, X-type molecular sieve, activated carbon, or a combination thereof, and more preferably, it is selected from activated clay, NaY molecular sieve, or a combination thereof.

[0030] In an even more preferred embodiment, the conditions of the pretreatment in step 1) are that the temperature is from room temperature to 60 °C, the pressure is 0.0 - 0.5 MPa, and the mass space velocity of the endo-tetrahydrodicyclopentadiene is 0.1 - 10.0 h -1 , preferably 0.2 - 1 h -1 .

[0031] In a specific embodiment, the pretreatment in step 1) is achieved by contacting the adsorbent with the reaction solvent in a pretreatment reactor that is not strictly limited, such as a fixed-bed reactor or a glass reaction tube.

[0032] Without being limited to a specific theory, the inventors of the present application have also found that by using a hydrogenation protecting agent in step 2), impurities such as trace olefins in the raw material endo-tetrahydrodicyclopentadiene can be removed by hydrogenation, hydrogen can be activated, the isomerization catalyst can be protected, its coking can be suppressed, and its lifespan can be extended.

[0033] In a preferred embodiment, the hydrogenation protecting agent includes a carrier and an active metal supported on the carrier. The active metal is selected from the group consisting of noble metals Pd, Pt, Ru, Rh, non-noble metal Ni, or a combination thereof, preferably selected from the group consisting of Ni, Pd, Pt, or a combination thereof. The carrier is selected from non-acidic carriers such as Al2O3, SiO2, ZrO2, TiO2, CeO2, activated carbon, or a combination thereof, preferably Al2O3, SiO2, or a combination thereof. In a more preferred embodiment, based on the total mass of the hydrogenation protective agent, the non-noble metal (Ni) content of the hydrogenation protective agent is 1 to 40%, preferably 5 to 30%, more preferably 10 to 20%. and / or the total content of noble metals (Pd, Pt, Ru, and Rh) is 0.1 to 10%, preferably 0.2 to 5%, more preferably 0.3 to 3%.

[0034] According to the present application, the hydrogenation protective agent may be prepared by a conventional process or is commercially available and is not strictly limited.

[0035] In the present application, the isomerization reaction in step 2) is carried out under the catalysis of a metal-modified molecular sieve catalyst (i.e., a metal / molecular sieve supported catalyst), and the catalyst has a dual function of isomerization and coking suppression. The molecular sieve exhibits stable isomerization activity by supporting a metal on the molecular sieve. The metal does not participate in the isomerization reaction, but suppresses the formation of coking precursors (such as olefin intermediates) in the reaction process, thereby improving the catalyst life.

[0036] In a preferred embodiment, the isomerization catalyst includes a molecular sieve and a modified metal supported on the molecular sieve. The modified metal is selected from noble metals Pd, Pt, Ru, Rh, Au, non-noble metal Ni, or a combination thereof, preferably selected from Pt, Pd, or a combination thereof. The molecular sieve is a Y-type molecular sieve, preferably selected from HY, USY, and REHY, or a combination thereof, more preferably selected from HY, HUSY, and REHY, or a combination thereof. Even more preferably, based on the total mass of the isomerization catalyst, the content of non-noble metal (Ni) in the isomerization catalyst is 1 to 20%, preferably 3 to 15%, more preferably 3 to 10%, and / or, the total content of noble metals (Pd, Pt, Au, Ru, and Rh) is 0.05 to 5.0%, preferably 0.1 to 1.0%, more preferably 0.2 to 0.5%. Even more preferably, the molecular sieve has a Na2O content of less than 0.5%, preferably less than 0.2%, based on the mass of the molecular sieve.

[0037] According to the present application, the isomerization catalyst is commercially available or may be prepared by a conventional process, such as an equivalent volume impregnation process, an excess volume impregnation process, etc. For example, a specific amount of a metal precursor solution is prepared according to the metal loading amount, and then the solution is impregnated into the molecular sieve, left standing at room temperature for more than 6 hours with intermittent stirring during the process, then dried at a temperature of 80 to 120°C for more than 12 hours, and calcined in an air atmosphere at a temperature of 450 to 550°C for 2 to 5 hours. Then, the calcined catalyst may be reduced in a reducing atmosphere such as hydrogen at 400 to 550°C for 2 to 5 hours to obtain an activated catalyst, thereby preparing the isomerization catalyst.

[0038] In a preferred embodiment, the isomerization catalyst has a specific surface area of 450 to 900 m 2 / g, preferably 600 to 800 m 2 / g, a pore volume of 0.25 to 0.5 cm 3 / g, preferably 0.35 to 0.45 cm 3 / g, 0.02 to 0.10 cm 3 / g, preferably 0.07 to 0.09 cm 3 / g of mesopore volume, 150 to 850 μmol / g, preferably 370 to 700 μmol / g of strong acid amount, and has.

[0039] In a more preferred embodiment, the isomerization catalyst is I) A step of modifying the Y-type molecular sieve by using an ammonium fluorosilicate solution, wherein the mass ratio of the ammonium fluorosilicate to the Y-type molecular sieve is 0.1 to 0.3, and the Y-type molecular sieve is preferably a hydrogen-type molecular sieve, more preferably selected from HY, HUSY, REHY, or combinations thereof; and, II) A step of supporting the modifying metal on the modified molecular sieve obtained in step I), calcining, and reducing in a reducing atmosphere to obtain the isomerization catalyst; is prepared by a method comprising.

[0040] In an even more preferred embodiment, the conditions of the modification treatment in step I) include a treatment temperature of 30 to 100 °C, preferably 50 to 80 °C, and a treatment time of 0.5 to 5 hours, preferably 0.5 to 3 hours. More preferably, the concentration of the ammonium fluorosilicate solution is 0.02 to 2 mol / L, preferably 0.05 to 0.3 mol / L.

[0041] In an even more preferred embodiment, the step of supporting in step II) is achieved by impregnating the modified molecular sieve with a solution of the precursor of the modifying metal and optionally drying. Preferably, the precursor is a salt of the modifying metal.

[0042] In a preferred embodiment, the first and second reaction zones in step 2) are under a hydrogen atmosphere, and the reaction pressure is 0.1 to 3 MPa, preferably 0.5 to 1.0 MPa. More preferably, the mass space velocity of the endo - tetrahydrodicyclopentadiene in the first and second reaction zones is 0.5 to 5 h -1 , preferably 0.5 to 2 h -1 , and the volume ratio of hydrogen to the liquid is 100 to 1600, preferably 600 to 1200.

[0043] In some specific embodiments, the exo - tetrahydrodicyclopentadiene and the reaction solvent are separated as intermediate products from the material after the reaction in step 2), whereby an adamantane concentrated solution can be obtained. The concentrated solution is cooled and crystallized to obtain a crude adamantane product, and an adamantane product with higher purity can be obtained by recrystallization. The exo - tetrahydrodicyclopentadiene and the reaction solvent can be reused. The atom utilization rate in the whole process is high.

[0044] In a preferred embodiment, step 2) is carried out using a fixed - bed reactor, and the first reaction zone is arranged above the second reaction zone. Preferably, the first reaction zone and the second reaction zone are separated by an inert material.

[0045] In a more preferred embodiment, the inert material may be selected from SiO2, Al2O3, carbon materials, quartz sand, etc., and preferably may be quartz sand.

[0046] In a specific preferred embodiment, the method of the present application is 1) a step of introducing endo - tetrahydrodicyclopentadiene and a reaction solvent into a pretreatment reactor filled with an adsorbent for pretreatment; and, 2) a step of introducing the effluent obtained in step 1) into a fixed - bed reactor for hydroisomerization reaction to obtain adamantane; It includes. Here, in the fixed-bed reactor, the upper first reaction zone is filled with a hydrogenation protective agent, and the lower second reaction zone is filled with an isomerization catalyst.

[0047] In a particular preferred embodiment, the method of the present application 1) The step of uniformly mixing end-tetrahydrodicyclopentadiene with a reaction solvent, introducing it into a pretreatment reactor, and adsorbing and removing impurities with adsorbents such as activated clay, NaY, and others; and 2) The step of flowing the effluent in step 1) into the upper end of a fixed-bed reactor and flowing it out from the lower end of the fixed-bed reactor; It includes. Here, in the fixed-bed reactor, a hydrogenation protective agent is filled in the upper first reaction zone, an isomerization catalyst is filled in the lower second reaction zone, and an inert material is arranged between them for separation. Here, the upper hydrogenation reaction temperature is 120 - 300 °C, the lower isomerization reaction temperature is 181 - 300 °C, the reaction pressure of the whole fixed bed is hydrogen at 0.1 - 3 MPa, the mass space velocity of end-tetrahydrodicyclopentadiene is 0.5 - 5 h -1 -1, and the volume ratio of hydrogen to the liquid is 100 - 1600.

[0048] According to the present application, in some embodiments, end-tetrahydrodicyclopentadiene and the reaction solvent are preliminarily mixed uniformly in a raw material tank, and then, under normal temperature and pressure, they are allowed to flow into a pretreatment reactor filled with an adsorbent from the upper end. The material without impurities flows out from the lower end, and then is fed into the upper end of a fixed-bed reactor, and passes through a hydrogenation protective agent, an inert material, and an isomerization catalyst reaction bed layer together with hydrogen. The reaction product flows out from the lower end of the fixed bed. The product includes exo-tetrahydrodicyclopentadiene, adamantane, and other ring-opening by-products. Adamantane can be obtained after separation.

[0049] According to the present application, gas chromatographic analysis is performed on the sample taken in step 2). The reactant conversion rate and the product selectivity are calculated according to the area normalization method.

[0050] According to the method of the first aspect of the present application, endo - tetrahydrodicyclopentadiene is used as a reaction raw material, and it passes through a first reaction zone filled with a hydrogenation protecting agent and a second reaction zone filled with an isomerization catalyst (for example, a fixed - bed reactor with the upper part filled with a hydrogenation protecting agent and the lower part filled with an isomerization catalyst) in sequence to carry out a hydroisomerization reaction. Preferably, after the adsorption pretreatment, the service life and process stability of the isomerization catalyst can be significantly improved. Green, continuous, and stable production of adamantane is realized. The conversion rate may reach 99%, and the selectivity of the target product, adamantane, may reach 15.9%. There is no tar generated, and the atom utilization rate is high. Continuous operation for more than 500 hours can be realized, and the said method has prospects for industrial application.

[0051] In a second aspect, the present application provides an isomerization catalyst for producing adamantane by isomerization of tetrahydrodicyclopentadiene, comprising a Y - type molecular sieve and a modified metal supported on the molecular sieve, I) a step of modifying the Y - type molecular sieve by using an ammonium fluorosilicate solution, wherein the mass ratio of the ammonium fluorosilicate to the Y - type molecular sieve is 0.1 - 0.3; and, II) a step of supporting the modified metal on the modified molecular sieve obtained in step I), calcining, and reducing in a reducing atmosphere to obtain the isomerization catalyst; An isomerization catalyst prepared by a method comprising the above is provided.

[0052] In a preferred embodiment, the Y - type molecular sieve is a hydrogen - type molecular sieve, more preferably selected from HY, HUSY, REHY, or a combination thereof.

[0053] In a preferred embodiment, the Y-type molecular sieve has an Na2O content of less than 0.5%, preferably less than 0.2%, based on the mass of the molecular sieve.

[0054] In a preferred embodiment, the modifying metal is selected from Pt, Pd, Au, Ru, Rh, Ni, or combinations thereof. More preferably, when the modifying metal is Pt, Pd, Au, Ru, and / or Rh, the loading amount of the modifying metal is 0.05 to 5.0%, preferably 0.2 to 0.5%, based on the total mass of the catalyst; when the modifying metal is Ni, it is 1.0 to 10%, preferably 3 to 6%.

[0055] In a preferred embodiment, the modification treatment in step I) is carried out by mixing the Y-type molecular sieve with water, stirring uniformly to form a slurry, adding an ammonium fluorosilicate solution into the slurry of the Y-type molecular sieve according to the requirement that the mass ratio of ammonium fluorosilicate to the molecular sieve is 0.1 to 0.3, treating at a temperature of 30 to 100 °C, preferably 50 to 80 °C, for 0.5 to 5 hours, preferably 0.5 to 3 hours, and then filtering and drying. More preferably, the mass ratio of the Y-type molecular sieve to water is 1:1 to 1:30, preferably 1:5 to 1:15, thereby forming a slurry.

[0056] In a preferred embodiment, the concentration of the ammonium fluorosilicate solution used in step I) is 0.02 to 2 mol / L, preferably 0.05 to 0.3 mol / L.

[0057] In a preferred embodiment, the step of loading in step II) is achieved by impregnating the modified molecular sieve into a solution of the precursor of the modifying metal and optionally drying. Preferably, the precursor of the modifying metal is a salt of the modifying metal.

[0058] In a preferred embodiment, in step II), the firing step includes firing at 350 to 600 ° C, preferably 400 to 500 ° C, for 1 to 6 hours, preferably 2 to 4 hours, and / or the reduction step includes reducing in a hydrogen atmosphere at 150 to 600 ° C, preferably 250 to 500 ° C, for more than 1 hour, for example, 2 to 5 hours.

[0059] According to the isomerization catalyst of the second aspect of the present application, the molecular sieve is first treated with an ammonium fluorosilicate solution, and as a result, the pores of the catalyst can be enlarged, and the effects of increasing the acid content and acid strength can be achieved. The activity and stability of the catalyst are improved. The dual-functional catalyst is prepared by further impregnating the metal onto the molecular sieve. The dual-functional catalyst has a remarkable effect of suppressing the coking and deactivation of the catalyst and can be used for producing adamantane by isomerization of tetrahydrodicyclopentadiene.

[0060] In a third aspect, the present application is a method for producing adamantane, including the step of contacting a liquid feed stream containing tetrahydrodicyclopentadiene, particularly endo-tetrahydrodicyclopentadiene, with an isomerization catalyst in a hydrogen atmosphere to carry out an isomerization reaction, wherein the isomerization catalyst has a specific surface area of 450 to 900 m 2 / g, preferably 600 to 800 m 2 / g, a pore volume of 0.25 to 0.5 cm 3 / g, preferably 0.35 to 0.45 cm 3 / g, a mesopore volume of 0.02 to 0.10 cm 3 / g, preferably 0.07 to 0.09 cm 3 / g, an amount of strong acid of 150 to 850 μmol / g, preferably 370 to 700 μmol / g, a reaction temperature of 181 to 300 ° C, preferably 200 to 260 ° C, and a reaction pressure of 0.1 to 3.0 MPa, preferably 0.5 to 1.0 MPa. Provided is a method using a metal-modified molecular sieve catalyst having

[0061] In a preferred embodiment, the mass space velocity of the end-tetrahydrodicyclopentadiene in the isomerization reaction is 0.2 to 5 h -1 , preferably 0.5 to 2 h -1 and the volume ratio of hydrogen to the liquid is 100 to 3000, preferably 600 to 1200.

[0062] In a preferred embodiment, the isomerization catalyst includes a molecular sieve and a modified metal supported on the molecular sieve, wherein the modified metal is selected from Pd, Pt, Au, Ru, Rh, Ni, or a combination thereof. The molecular sieve is a Y-type molecular sieve, preferably selected from HY, USY, REHY, or a combination thereof, more preferably selected from HY, HUSY, REHY, or a combination thereof. Even more preferably, based on the total mass of the isomerization catalyst, the content of Ni in the isomerization catalyst is 1 to 20%, preferably 3 to 15%, more preferably 3 to 10%, and / or the total content of Pd, Pt, Au, Ru, and Rh is 0.05 to 5.0%, preferably 0.1 to 1.0%, more preferably 0.2 to 0.5%. Even more preferably, the molecular sieve has a Na2O content of less than 0.5%, preferably less than 0.2%, based on the mass of the molecular sieve.

[0063] In a particularly preferred embodiment, the isomerization catalyst I) a step of modifying the Y-type molecular sieve by using an ammonium fluorosilicate solution, The mass ratio of the ammonium fluorosilicate to the Y-type molecular sieve is 0.1 to 0.3. The Y-type molecular sieve is preferably a hydrogen-type molecular sieve, more preferably selected from HY, HUSY, REHY, or a combination thereof, step; and, II) Supporting a reforming metal on the reformed molecular sieve obtained in step I), firing, and reducing in a reducing atmosphere to obtain the isomerization catalyst; is prepared by a method comprising.

[0064] In a more preferred embodiment, the conditions of the reforming treatment in step I) include a treatment temperature of 30 to 100°C, preferably 50 to 80°C, and a treatment time of 0.5 to 5 hours, preferably 0.5 to 3 hours. More preferably, the concentration of the ammonium fluorosilicate solution is 0.02 to 2 mol / L, preferably 0.05 to 0.3 mol / L.

[0065] In a more preferred embodiment, the supporting step in step II) is achieved by impregnating the reformed molecular sieve with a solution of a precursor of the reforming metal and optionally drying. Preferably, the precursor is a salt of the reforming metal.

[0066] In a preferred embodiment, the feed stream comprises endo-tetrahydrodicyclopentadiene and a reaction solvent selected from a hydrocarbon or halogenated hydrocarbon solvent having a boiling point of 40 to 300°C. The hydrocarbon or halogenated hydrocarbon solvent is preferably selected from C6 - C10 hydrocarbons, more preferably selected from cyclohexane, methylcyclohexane, exo-tetrahydrodicyclopentadiene, or a combination thereof. More preferably, the mass concentration of the endo-tetrahydrodicyclopentadiene in the feed stream is 10 to 80%, more preferably 30 to 60%.

[0067] In a preferred embodiment, the isomerization reaction is carried out in a reactor selected from a fixed bed, a moving bed, a fluidized bed, a slurry bed, or a combination thereof, preferably in a fixed bed reactor.

[0068] In a preferred embodiment, the method further comprises a step of pretreating the liquid feed stream containing tetrahydrodicyclopentadiene with an adsorbent before the isomerization reaction.

[0069] In a more preferred embodiment, the adsorbent is selected from activated clay, NaY molecular sieve, X-type molecular sieve, activated carbon, or a combination thereof, and more preferably, it is selected from activated clay, NaY molecular sieve, or a combination thereof.

[0070] In an even more preferred embodiment, the conditions of the pretreatment include a temperature from room temperature to 60 °C, a pressure of 0.0 - 0.5 MPa, and a mass space velocity of endo-tetrahydrodicyclopentadiene of 0.1 - 10.0 h -1 , preferably 0.2 - 1 h -1 . The other features of the pretreatment step are as described in the first aspect of the present application and will not be described again herein.

[0071] In a specific preferred embodiment, the present application provides the following.

[0072] A1. A continuous method for continuously and stably producing adamantane, comprising: introducing endo-tetrahydrodicyclopentadiene and a reaction solvent into a pretreatment reactor filled with an adsorbent for pretreatment, and introducing the effluent into a fixed bed reactor for hydroisomerization reaction to obtain adamantane; including in the fixed bed reactor, the upper part is filled with a hydrogenation protective agent and the lower part is filled with an isomerization catalyst, wherein the temperature of the upper hydrogenation reaction is 120 - 300 °C and the temperature of the lower isomerization reaction is 181 - 300 °C.

[0073] A2. The upper hydrogenation reaction temperature in the method according to item A1 is 151 to 250 °C, and the temperature of the lower isomerization reaction is 200 to 260 °C.

[0074] A3. The reaction solvent in the method according to item A1 is selected from solvents having a boiling point of 40 to 300 °C, preferably selected from C6 - C10 hydrocarbons such as cyclohexane, methylcyclohexane, and exo - tetrahydrodicyclopentadiene.

[0075] A4. In the method according to item A1, after the endo - tetrahydrodicyclopentadiene is mixed with the reaction solvent, it has a mass concentration of 10 to 80%, preferably 30 to 60%.

[0076] A5. The pretreatment reactor in the method according to item A1 includes, but is not limited to, a fixed - bed reactor or a glass reaction tube.

[0077] A6. The adsorbent in the method according to item A1 is selected from activated clay, NaY molecular sieve, X - type molecular sieve, and activated carbon, preferably selected from activated clay and NaY molecular sieve.

[0078] A7. The pretreatment temperature ranges from room temperature to 60 °C, the pretreatment pressure is 0.0 to 0.5 MPa, and the mass space velocity of the endo - tetrahydrodicyclopentadiene is 0.1 to 10.0 h -1 , preferably 0.2 to 1 h -1 in the method according to item A1.

[0079] A8. The active metal of the hydrogenation protective agent is selected from one or more of noble metals Pd, Pt, Ru, Rh, and non - noble metal Ni, preferably selected from one or more of Ni, Pd, Pt. The carrier is a non - acidic carrier and is selected from Al2O3, SiO2, ZrO2, TiO2, CeO2, and activated carbon, preferably selected from Al2O3 and SiO2, etc. in the method according to item A1.

[0080] A9. Based on the total mass of the hydrogenation protecting agent, the supported amount of the non-noble metal is 1 to 40%, preferably 5 to 30%, more preferably 10 to 20%, the supported amount of the noble metal is 0.1 to 10%, preferably 0.2 to 5%, more preferably 0.3 to 3% in the method of clause A8.

[0081] A10. The isomerization catalyst is a metal-modified molecular sieve catalyst, the modifying metal is selected from one or more of the noble metals Pd, Pt, Ru, Rh, and the non-noble metal Ni, the molecular sieve is selected from HY, USY, REHY, NTY, and SSY, preferably a Y-type molecular sieve selected from HY, USY, and REHY in the method of clause A1.

[0082] A11. Based on the total mass of the isomerization catalyst, the supported amount of the non-noble metal is 1 to 20%, preferably 3 to 15%, more preferably 5 to 10%, the supported amount of the noble metal is 0.05 to 3%, preferably 0.1 to 1.0%, more preferably 0.2 to 0.5% in the method of clause A10.

[0083] A12. In the fixed bed reactor, the reaction pressure of the system is hydrogen at 0.1 to 3 MPa, preferably hydrogen at 0.5 to 1.0 MPa in the method of clause A1.

[0084] A13. In the fixed bed reactor, the endo-tetrahydrodicyclopentadiene has a mass space velocity of 0.5 to 5 h -1 , preferably 0.5 to 2 h -1 and the volume ratio of hydrogen to the liquid is 100 to 1600, preferably 600 to 1200 in the method of clause A1.

[0085] B1. A catalyst for producing adamantane by isomerization of tetrahydrodicyclopentadiene, Comprising a Y-type molecular sieve and a modified metal. The method for producing the catalyst comprises modifying the Y-type molecular sieve with an ammonium fluorosilicate solution, wherein the mass ratio of the ammonium fluorosilicate to the molecular sieve is 0.1 - 0.3, impregnating the treated molecular sieve with a metal precursor, drying, calcining, and reducing in a reducing atmosphere.

[0086] B2. The Y-type molecular sieve is a hydrogen-type molecular sieve, preferably one or more of HY, HUSY, and REHY, in the catalyst of clause B1.

[0087] B3. The Y-type molecular sieve contains less than 0.5% by mass, preferably less than 0.2% by mass of Na2O, in the catalyst of clause B1.

[0088] B4. The Y-type molecular sieve is modified with an ammonium fluorosilicate solution, and the modification conditions include mixing the Y-type molecular sieve with water, stirring uniformly to form a slurry, and adding the ammonium fluorosilicate solution into the slurry of the Y-type molecular sieve according to the requirement that the mass ratio of the ammonium fluorosilicate to the molecular sieve is 0.1 - 0.3, in the catalyst of clause B1.

[0089] B5. The modification treatment conditions include a treatment temperature of 30 - 100°C, preferably 50 - 80°C, a treatment pressure of 0.5 - 5 hours, preferably 0.5 - 3 hours, and filtering and drying after treatment, in the catalyst of clause B1.

[0090] B6. The metal is one or more selected from Pt, Pd, Au, Ru, Rh, and Ni, and the metal precursor is a salt of the metal, in the catalyst of clause B1.

[0091] B7. The metal is Pt, Pd, Au, Ru, or Rh, the metal loading is 0.05 to 5.0%, preferably 0.2 to 0.5%, and when the metal is Ni, the metal loading is 1.0 to 10%, preferably 3 to 6%, the catalyst in clause B1.

[0092] B8. The concentration of the ammonium fluorosilicate solution is 0.02 to 2 mol / L, preferably 0.05 to 0.3 mol / L, the catalyst in clause B1.

[0093] B9. The mass ratio of the Y-type molecular sieve to water is 1:1 to 1:30, preferably 1:5 to 1:15, the catalyst in clauses B1 and B4.

[0094] B10. A method for producing adamantane, comprising the step of mixing the tetrahydrodicyclopentadiene and a solvent in a reactor and reacting them in the presence of hydrogen and a catalyst according to any one of B1 to B9, the reaction temperature is 181 to 300 °C, preferably 200 to 260 °C, the pressure of the reaction hydrogen (gauge pressure) is 0.1 to 3.0 MPa, preferably 0.5 to 1.0 MPa, the method.

[0095] B11. The end-tetrahydrodicyclopentadiene has a mass space velocity of 0.2 to 5 h -1 preferably 0.5 to 2 h -1 and the volume ratio of hydrogen to the liquid is 100 to 3000, preferably 600 to 1200, the method in clause B10.

[0096] B12. The tetrahydrodicyclopentadiene is mixed with a solvent before the reaction, and the mass concentration of the tetrahydrodicyclopentadiene in the mixed solution is 10 to 80% by weight, preferably 30 to 60% by weight, the method in clause B10.

[0097] B13. The solvent is a hydrocarbon or halogenated hydrocarbon solvent having a boiling point of 40 to 300 °C, The hydrocarbon or halogenated hydrocarbon solvent in the method of Clause B10 is preferably a C6-C10 hydrocarbon, more preferably cyclohexane, methylcyclohexane, exo-tetrahydrodicyclopentadiene, or a combination thereof.

[0098] B14. In the method of Clause B10, the reactor may be a fixed-bed reactor, a moving-bed reactor, a fluidized bed, a slurry bed, preferably a fixed-bed reactor.

[0099] 〔Examples〕 This application will be further described below in connection with examples, but the application is not limited thereby.

[0100] [Example I Series] In the following series of Example I, the effects of different operating conditions on the method for producing adamantane of the first aspect of the present application in a fixed-bed reactor including a hydrogenation section (i.e., the first reaction zone) and an isomerization section (i.e., the second reaction zone) were tested. Here, endo-tetrahydrodicyclopentadiene is available from Beijing InnoChem Technology Co., Ltd., and quartz sand was filled as an inert material between the hydrogenation zone and the isomerization zone.

[0101]

Number

[0102] <Examples I-1 to I-7 and Comparative Examples I-1 to I-2 (Effect of Hydrogenation Protectant)> A methylcyclohexane solution containing 50% by weight of endo-tetrahydrodicyclopentadiene was used as the raw material. The raw material was uniformly mixed in advance and then passed through the hydrogenation section and the isomerization section in sequence.

[0103] In a fixed-bed reactor, 0.3 wt% of Pt / HY was used as an isomerization catalyst, and the reaction temperature in the isomerization section was 220°C. The composition of the hydrogenation protective agent and the temperature in the hydrogenation section are shown in Table I-1. The reaction pressure was 0.5 MPa of hydrogen. The mass space velocity of endo-tetrahydrodicyclopentadiene was 1 h -1 . The volume ratio of hydrogen to liquid was 1000. After 20 hours of reaction, sampling analysis was carried out to examine the effect of the hydrogenation protective agent on the reaction performance. The results are shown in Table I-1.

[0104]

Table 1

[0105] *The ring-opening by-products mainly refer to C10 hydrocarbons such as decalin and were calculated based on the molar amount of the C10 components (the same applies hereinafter).

[0106] As can be seen from the reaction results in Table I-1, the method of the present application can significantly improve the reaction conversion rate and adamantane selectivity by using a hydrogenation protective agent.

[0107] <Examples I-8 to I-9 and Comparative Examples I-3 to I-4 (Effect of the pretreatment process)> In a pretreatment reactor, a methylcyclohexane solution containing 50 wt% of endo-tetrahydrodicyclopentadiene was used as a raw material and passed through a pretreatment reactor filled with different adsorbents at normal temperature and pressure. Here, the mass space velocity of endo-tetrahydrodicyclopentadiene was 0.5 h -1 . Then, after pretreatment, the methylcyclohexane solution was fed into a fixed-bed reactor.

[0108] In a fixed-bed reactor, a methylcyclohexane solution containing 50 wt% of endo-tetrahydrodicyclopentadiene after different pretreatment processes was used as a raw material, and 20 wt% Ni / SiO2 was used as a hydrogenation protective agent. Here, the reaction temperature in the hydrogenation section was 200 °C. 0.3 wt% Pt / HY was used as an isomerization catalyst, the reaction temperature in the isomerization section was 220 °C, the reaction pressure for the entire fixed bed was 0.5 MPa of hydrogen, and the mass space velocity of endo-tetrahydrodicyclopentadiene was 1 h -1 -1, and the volume ratio of hydrogen to liquid was 1000. After 10 hours and 50 hours of reaction, sampling and analysis were carried out to investigate the influence of the pretreatment process on the reaction results. The results are shown in Table I-2.

[0109]

Table 2

[0110] As can be seen from the reaction results in Table I-2, the method of the present application can significantly improve the stability of the reaction system by using a pretreatment step.

[0111] <Examples I-10 to I-14 and Comparative Examples I-5 to I-6 (Effect of Isomerization Catalyst)> In a pretreatment reactor, a methylcyclohexane solution containing 50 wt% of endo-tetrahydrodicyclopentadiene was used as a raw material. After uniformly mixing the raw materials in advance, impurities were removed by NaY pretreatment.

[0112] In a fixed-bed reactor, 20 wt% Ni / SiO2 was used as a hydrogenation protection catalyst. The reaction temperature of the hydrogenation protection agent was 200 °C. The temperature in the isomerization section was 220 °C. The composition of the isomerization catalyst is shown in Table I-3. The reaction pressure was 0.5 MPa of hydrogen. The mass space velocity of endo-tetrahydrodicyclopentadiene was 1 h -1It was. The volume ratio of hydrogen to the liquid was 1000. After the reaction for 50 hours, sampling and analysis were carried out to examine the influence of the composition of the isomerization catalyst on the reaction performance. The results are shown in Table I-3.

[0113]

Table 3

[0114] <Examples I-15 to I-17 and Comparative Example I-7 (Effect of Isomerization Reaction Temperature)> A methylcyclohexane solution containing 50 wt% of endo-tetrahydrodicyclopentadiene was used as the raw material. After uniformly mixing the raw materials in advance, impurities were removed by NaY pretreatment. 20 wt% Ni / SiO2 was used as the hydrogenation protective agent. The temperature of the hydrogenation section was 200 °C. 0.3 wt% of Pt / HY was used as the isomerization catalyst. The reaction pressure of the entire fixed bed was 0.5 MPa of hydrogen. The mass space velocity of endo-tetrahydrodicyclopentadiene was 1 h -1 It was. The volume ratio of hydrogen to the liquid was 1000. After the reaction for 10 hours, sampling and analysis were carried out to examine the influence of the isomerization reaction temperature. The results are shown in Table I-4.

[0115]

Table 4

[0116] <Examples I-18 to I-21 (Effect of Reaction Pressure)> A methylcyclohexane solution containing 50 wt% of endo-tetrahydrodicyclopentadiene was used as the raw material. After uniformly mixing the raw materials in advance, impurities were removed by NaY pretreatment. 20 wt% Ni / SiO2 was taken as the hydrogenation protective agent. The temperature of the hydrogenation section was 200 °C. 0.3 wt% of Pt / HY was used as the isomerization catalyst. The reaction temperature of the isomerization section was 220 °C. The mass space velocity of endo-tetrahydrodicyclopentadiene was 1 h -1It was. The volume ratio of hydrogen to the liquid was 1000. After 10 hours of reaction, sampling and analysis were performed to examine the influence of the reaction pressure of the system in a hydrogen atmosphere. The results are shown in Table I-5.

[0117] [Table 5]

[0118] <Examples I-22 to I-25 (Effect of mass space velocity)> A methylcyclohexane solution containing 50 wt% endo-tetrahydrodicyclopentadiene was used as the raw material. After uniformly mixing the raw materials in advance, impurities were removed by NaY pretreatment. 20 wt% Ni / SiO2 was used as the hydrogenation protective agent. The temperature of the hydrogenation section was 200 °C. 0.3 wt% Pt / HY was used as the isomerization catalyst. The reaction temperature in the isomerization section was 220 °C. The reaction pressure of the entire fixed bed was 0.5 MPa of hydrogen. The volume ratio of hydrogen to the liquid was 1000. After 10 hours of reaction, sampling and analysis were performed to examine the influence of the mass space velocity of endo-tetrahydrodicyclopentadiene. The results are shown in Table I-6.

[0119] [Table 6]

[0120] <Examples I-26 to I-28 (Effect of volume ratio of hydrogen to liquid)> A methylcyclohexane solution containing 50 wt% endo-tetrahydrodicyclopentadiene was used as the raw material. After uniformly mixing the raw materials in advance, impurities were removed by NaY pretreatment. 20 wt% Ni / SiO2 was used as the hydrogenation protective agent. The temperature of the hydrogenation section was 200 °C. 0.3 wt% Pt / HY was used as the isomerization catalyst. The reaction temperature in the isomerization section was 220 °C. The reaction pressure of the entire fixed bed was 0.5 MPa of hydrogen. The mass space velocity of endo-tetrahydrodicyclopentadiene was 1 h -1It was. After 10 hours of reaction, sampling and analysis were carried out to examine the influence of the volume ratio of hydrogen to liquid. The results are shown in Table I-7.

[0121] [Table 7]

[0122] <Examples I-29 to I-32 and Comparative Example I-8 (Effect of Reaction Solvent and Raw Material Mass Concentration)> Endo-tetrahydrodicyclopentadiene solutions with different mass concentrations were used as raw materials. After uniformly mixing the raw materials in advance, impurities were removed by NaY pretreatment. 20 wt% Ni / SiO2 was used as a hydrogenation protective agent. The temperature of the hydrogenation section was 200 °C. 0.3 wt% Pt / HY was used as an isomerization catalyst. The reaction temperature of the isomerization section was 220 °C. The reaction pressure of the entire fixed bed was 0.5 MPa of hydrogen. The mass space velocity of endo-tetrahydrodicyclopentadiene was 1 h -1 It was. The volume ratio of hydrogen to liquid was 1000. After 10 hours of reaction, sampling and analysis were carried out to examine the influence of different reaction solvents and raw material mass concentrations. The results are shown in Table I-8.

[0123] [Table 8]

[0124] <Example I-33 (System Stability Test)> (With NaY pretreatment) The operating period of Example I-1 was further extended to 500 hours. The results show that the conversion rate of endo-THDCPD was 99%. The selectivity of exo-THDCPD was 71.2%. The selectivity of adamantane was 14.9%. The selectivity of ring-opening by-products was 13.9%. These results indicate that the system has better stability, effectively solves the problem of catalyst coking, and has the potential for industrial application.

[0125] [Example II Series] In the following series of Example II, the effects of different isomerization operating conditions on the process for the production of adamantane of the present application in a fixed-bed reactor were tested. Here, ammonium fluorosilicate and end-tetrahydrodicyclopentadiene are available from Beijing Innochem Science & Technology Co., Ltd.

[0126] The specific surface area of the catalyst and the pore volume (including the mesopore volume) were measured by the Quantachrome AS-3 type and AS-6 type static nitrogen adsorption apparatuses according to the nitrogen isothermal physical adsorption and desorption process (BET). The test conditions were as follows. The sample was placed in the sample treatment system, evacuated to 1.33×10 -2 Pa at 350 °C, and maintained at constant temperature and pressure for 15 hours to decontaminate the sample surface. At the liquid nitrogen temperature of -196 °C, the adsorption amount and desorption amount of N2 for the sample were measured under different relative pressures (p / p0) to obtain the adsorption-desorption isotherm curve. Then, the isothermal adsorption data of p / p0 from 0 to 0.25 in the linear part of the adsorption branch of the N2 adsorption-desorption curve were selected, and the specific surface area of the sample was calculated using the BET equation, and the adsorption amount at a relative pressure p / p0 < 0.98 was selected as the pore volume information of the sample.

[0127] The total acid content and strong acid content of the catalyst were determined by pyridine adsorption infrared spectroscopy (Py-IR) using the Bio-Rad FTS3000 Fourier transform infrared spectrometer of the United States. As the test conditions, a vacuum was applied to 1×10 -3 Pa at 350 °C, and the wave number range was set to 1400 - 1700 cm -1 . As the test process, the pressed sample was placed in the infrared in-situ cell and sealed. First, it was evacuated to 1×10 -3 Pa at 350 °C and maintained for 1 hour to completely desorb the impurity gas molecules adsorbed by the sample. Then, the sample was cooled to room temperature. Pyridine was introduced into the in-situ cell at a pressure of 2.67 Pa. The system was averaged for 30 minutes, heated to 200 °C, and evacuated to 1×10 -3 Pa again. The pyridine molecules that were not adsorbed were removed. The system was maintained for 30 minutes and cooled to room temperature again. The sample was measured in the range of 1300 - 3900 cm-1 Scan in the wavenumber range, record the pyridine adsorption infrared absorption spectrum at 200 °C, then move the in-situ infrared absorption cell to the heat treatment area, heat it to 350 °C, evacuate to 1×10 -3 Pa and keep it for 30 minutes, then cool it to room temperature. The pyridine adsorption infrared spectrum at 350 °C was recorded. As a result, information on the total acid content and strong acid content could be obtained.

[0128] <Examples II-1 to II-2 and Comparative Example II-1 (Effect of Na2O content in molecular sieve)> HY molecular sieves with different Na2O contents were dried and then impregnated with metallic platinum. The metal precursor was tetraammineplatinum chloride, with a loading of 0.3%. The incipient wetness impregnation process was used, and the impregnation was continued at room temperature for 6 hours. During the process, it was intermittently stirred. Then, it was dried at 80 °C, calcined at 450 °C for 3 hours, and reduced with hydrogen at 400 °C for 3 hours. Binary functional catalysts with different Na2O contents were obtained and their catalytic activities were evaluated (results after 10 hours of reaction). Here, in a fixed-bed reactor, a methylcyclohexane solution containing 50 wt% of endo-tetrahydrodicyclopentadiene (endo-THDCPD) was used as the raw material. The reaction temperature was 220 °C, the reaction pressure (gauge pressure) was 0.5 MPa H2, the mass space velocity of endo-THDCPD was 1 h -1 and the volume ratio of hydrogen to the liquid was 1000. The performance of the catalyst was investigated (results after 10 hours of reaction). The results are shown in Table II-1.

[0129]

Table 9

[0130] <Examples II-3 to II-5 and Comparative Examples II-2 to II-3 (Effect of ammonium fluorosilicate treatment)> The HY molecular sieve (with a Na2O content of 0.07%) was dried, and then the HY molecular sieve and water were mixed and stirred uniformly to form a slurry. Subsequently, the slurry was treated with ammonium fluorosilicate. According to the requirement that the mass ratio of ammonium fluorosilicate to the HY molecular sieve was 0, 0.1, 0.2, 0.3, and 0.4, a 0.1 mol / L ammonium fluorosilicate solution was slowly added dropwise to the HY molecular sieve slurry, and then it was left standing at 60 °C for 1 hour. Finally, after washing and drying, HY molecular sieves modified with different amounts of ammonium fluorosilicate were obtained. The specific surface area, pore volume, mesopore volume, acid content, etc. of the catalyst were further characterized and analyzed. At the same time, metal loading and catalyst activity evaluation (results after 10 hours of reaction) were carried out according to the process described in Example II-1. The results are shown in Table II-2.

[0131]

Table 10

[0132] <Examples II-6 to II-12 and Comparative Example II-4 (effects of ammonium fluorosilicate concentration, treatment temperature, and time)> The HY molecular sieve (with a Na2O content of 0.07%) was dried, and then the HY molecular sieve was mixed with water and stirred uniformly to form a slurry. The ammonium fluorosilicate treatment was carried out according to the steps and ratios of Example II-3, but the concentration of the ammonium fluorosilicate solution was adjusted to 0.05 mol / L or 0.3 mol / L. In addition, the treatment temperature of ammonium fluorosilicate was adjusted to 50 °C or 80 °C, and the treatment time was adjusted to 0.5 hours or 3 hours. Metal loading and catalyst activity evaluation were carried out according to the process described in Example II-1 (results after 10 hours of reaction). The results are shown in Table II-3.

[0133]

Table 11

[0134] <Examples II-13 to II-16 and Comparative Examples II-5 to II-7 (Effect of Supported Metal)> HY molecular sieve (with a Na2O content of 0.07%) was dried and then treated with ammonium fluorosilicate. According to the process of Example II-3, the ammonium fluorosilicate solution was slowly added dropwise to the HY molecular sieve slurry according to the requirement that the mass ratio of ammonium fluorosilicate to the HY molecular sieve was 0.1. Then, the HY molecular sieve slurry was allowed to stand at 60°C for 1 hour and finally washed and dried to obtain an HY molecular sieve modified with ammonium fluorosilicate. Thereafter, the raw material was pretreated by adsorption using NaY according to the process in Example I-1. Then, metal loading and catalytic activity evaluation (results after 50 hours of reaction) were carried out according to the process described in Example II-1, but the type and loading amount of the supported metal were adjusted, and the results are shown in Table II-4.

[0135]

Table 12

[0136] <Examples II-17 to II-20 and Comparative Example II-8 (Effect of Reaction Temperature)> HY molecular sieve (with a Na2O content of 0.07%) was dried and then treated with ammonium fluorosilicate. According to the process of Example II-3, the ammonium fluorosilicate solution was slowly added dropwise to the HY molecular sieve slurry according to the requirement that the mass ratio of ammonium fluorosilicate to the HY molecular sieve was 0.1. Then, the HY molecular sieve slurry was allowed to stand at 60°C for 1 hour and finally washed and dried to obtain an HY molecular sieve modified with ammonium fluorosilicate. Thereafter, metal loading and catalytic activity evaluation (results after 10 hours of reaction) were carried out according to the process described in Example II-1, but the reaction temperature was adjusted to 180°C, 260°C, and 300°C, respectively. The results are shown in Table II-5.

[0137]

Table 13

[0138] <Examples II-21 to II-23 and Comparative Example II-9 (Effect of reaction pressure)> HY molecular sieve (Na2O content of 0.07%) was dried and then treated with ammonium fluorosilicate. According to the process of Example II-3, an ammonium fluorosilicate solution was slowly added dropwise to the HY molecular sieve slurry according to the requirement that the mass ratio of ammonium fluorosilicate to HY molecular sieve was 0.1, and then left standing at 60 °C for 1 hour. Finally, it was washed and dried to obtain an HY molecular sieve modified with ammonium fluorosilicate. Then, metal loading and catalytic activity evaluation (results after 10 hours of reaction) were carried out according to the process described in Example II-1, but the reaction hydrogen pressure (gauge pressure) was adjusted to 0 MPa, 0.5 MPa, 1.0 MPa, and 2.0 MPa. The results are shown in Table II-6.

[0139]

Table 14

[0140] <Examples II-24 to II-27 (Effect of mass space velocity)> The HY molecular sieve (with a Na2O content of 0.07%) was dried and then treated with ammonium fluorosilicate. According to the procedure of Example II-3, the ammonium fluorosilicate solution was slowly added dropwise to the HY molecular sieve slurry according to the requirement that the mass ratio of ammonium fluorosilicate to the HY molecular sieve was 0.1, then left standing at 60 °C for 1 hour, and finally washed and dried to obtain an HY molecular sieve modified with ammonium fluorosilicate. Thereafter, metal loading and catalytic activity evaluation (results after 10 hours of reaction) were carried out according to the process described in Example II-1, but the mass space velocity of endo-tetrahydrodicyclopentadiene was adjusted to 0.5 h -1 , 1.0 h -1 , 2.0 h -1 , 4.0 h -1 . The results are shown in Table II-7.

[0141]

Table 15

[0142] <Examples II-28 to II-30 and Comparative Example II-10 (Effect of Reaction Solvent)> The HY molecular sieve (with a Na2O content of 0.07%) was dried and then treated with ammonium fluorosilicate. According to the procedure of Example II-3, the ammonium fluorosilicate solution was slowly added dropwise to the HY molecular sieve slurry according to the requirement that the mass ratio of ammonium fluorosilicate to the HY molecular sieve was 0.1, then left standing at 60 °C for 1 hour, and finally washed and dried to obtain an HY molecular sieve modified with ammonium fluorosilicate. Thereafter, metal loading and catalytic activity evaluation (results after 10 hours of reaction) were carried out according to the process described in Example II-1, but the reaction solvent was replaced with exo-tetrahydrodicyclopentadiene, dichloromethane, and isopropanol. The results are shown in Table II-8.

[0143]

Table 16

[0144] Although the preferred embodiments of the present application have been described in detail above, the present application is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present application, the technical solutions of the present application may be subjected to various simple modifications, and all of these simple modifications belong to the protection scope of the present application.

[0145] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. To avoid unnecessary repetition, the present application will not describe various possible combinations any further.

[0146] In addition, various different implementations of the present application may be arbitrarily combined, and as long as they do not conflict with the idea of the present application, they should also be regarded as the content invented in the present application.

Claims

1. A continuous process for producing adamantane, comprising: 1) Supplying a liquid feed stream containing endo - tetrahydrodicyclopentadiene; 2) Passing the liquid feed stream successively through a first reaction zone filled with a hydrogenation protecting agent and a second reaction zone filled with an isomerization catalyst to carry out a hydroisomerization reaction to obtain adamantane; wherein the reaction temperature in the first reaction zone is 120 - 300 °C, preferably 151 - 250 °C, the reaction temperature in the second reaction zone is 181 - 300 °C, preferably 200 - 260 °C, the hydrogenation protecting agent is a supported metal hydrogenation catalyst, and the isomerization catalyst is a metal - modified molecular sieve catalyst.

2. The liquid feed stream contains endo - tetrahydrodicyclopentadiene and a reaction solvent selected from hydrocarbons or halogenated hydrocarbon solvents having a boiling point of 40 - 300 °C, the hydrocarbon or halogenated hydrocarbon solvent is preferably selected from C6 - C10 hydrocarbons, more preferably selected from cyclohexane, methylcyclohexane, exo - tetrahydrodicyclopentadiene, or combinations thereof, preferably, the mass concentration of endo - tetrahydrodicyclopentadiene in the feed stream is 10 - 80%, more preferably 30 - 60%. The method according to claim 1.

3. Step 1) further comprises a step of pretreating the liquid feed stream containing endo - tetrahydrodicyclopentadiene with an adsorbent, preferably, the adsorbent is selected from activated clay, NaY molecular sieve, X - type molecular sieve, activated carbon, or combinations thereof, preferably selected from activated clay, NaY molecular sieve, or combinations thereof. More preferably, the conditions of the pretreatment in step 1) are a temperature from normal temperature to 60°C, a pressure of 0.0 to 0.5 MPa, and a mass space velocity of the end-tetrahydrodicyclopentadiene of 0.1 to 10.0 h －１ , preferably 0.2 to 1 h －１ , and the method according to claim 1 or 2, comprising the mass space velocity of the end-tetrahydrodicyclopentadiene as described above.

4. The hydrogenation protecting agent contains a carrier and an active metal supported on the carrier, the active metal is selected from Pd, Pt, Ru, Rh, Ni, or combinations thereof, preferably selected from Ni, Pd, Pt, or combinations thereof, The carrier is Al ２ O ３ , SiO ２ , ZrO ２ , TiO ２ , CeO ２ , activated carbon, or a combination thereof, preferably, Al ２ O ３ , SiO ２ , or a non-acidic carrier selected from a combination thereof, preferably, based on the total mass of the hydrogenation protecting agent, the Ni content in the hydrogenation protecting agent is 1 - 40%, preferably 5 - 30%, more preferably 10 - 20%, and / or The total content of Pd, Pt, Ru, and Rh is 0.1 to 10%, preferably 0.2 to 5%, more preferably 0.3 to 3%. The method according to any one of claims 1 to 3.

5. The isomerization catalyst includes a molecular sieve and a reforming metal supported on the molecular sieve. The reforming metal is selected from Pd, Pt, Au, Ru, Rh, Ni, or a combination thereof. The molecular sieve is a Y-type molecular sieve, preferably selected from HY, USY, REHY, or a combination thereof, more preferably selected from HY, HUSY, REHY, or a combination thereof. Preferably, based on the total mass of the isomerization catalyst The content of Ni in the isomerization catalyst is 1 to 20%, preferably 3 to 15%, more preferably 3 to 10%. And / or The total content of Pd, Pt, Au, Ru, and Rh is 0.05 to 5.0%, preferably 0.1 to 1.0%, more preferably 0.2 to 0.5%. More preferably, the molecular sieve has an Na ２ O content of less than 0.5%, preferably less than 0.2%, based on the mass of the molecular sieve, according to any one of claims 1 to 4.

6. The isomerization catalyst 450 to 900 m ２ / g, preferably 600 to 800 m ２ / g of specific surface area, 0.25 to 0.5 cm ３ / g, preferably 0.35 to 0.45 cm ３ / g of pore volume, 0.02 to 0.10 cm ３ / g, preferably 0.07 to 0.09 cm ３ / g of mesopore volume, has an amount of strong acid of 150 to 850 μmol / g, preferably 370 to 700 μmol / g, The method according to claim 5.

7. The isomerization catalyst I) A step of modifying the Y-type molecular sieve by using an ammonium fluorosilicate solution, wherein the mass ratio of the ammonium fluorosilicate to the Y-type molecular sieve is 0.1 to 0.3, the Y-type molecular sieve is preferably a hydrogen-type molecular sieve, more preferably selected from HY, HUSY, REHY, or a combination thereof; and II) A step of supporting the reforming metal on the modified molecular sieve obtained in step I), calcining, and reducing in a reducing atmosphere to obtain the isomerization catalyst; is prepared by a method including Preferably, the supporting step in step II) is achieved by impregnating the modified molecular sieve with a solution of a precursor of the reforming metal and optionally drying. The precursor is preferably a salt of the reforming metal. The method according to claim 5 or 6.

8. The conditions of the modification treatment in step I) include a treatment temperature of 30 to 100°C, preferably 50 to 80°C, and a treatment time of 0.5 to 5 hours, preferably 0.5 to 3 hours. The method according to claim 7, wherein preferably, the concentration of the ammonium fluorosilicate solution is 0.02 to 2 mol / L, preferably 0.05 to 0.3 mol / L.

9. The first and second reaction zones are under a hydrogen atmosphere, and the reaction pressure is 0.1 to 3 MPa, preferably 0.5 to 1.0 MPa. Preferably, the mass space velocity of the end-tetrahydrodicyclopentadiene in the first and second reaction zones is 0.5 to 5 h －１ , preferably 0.5 to 2 h －１ and the volume ratio of hydrogen to the liquid is 100 to 1600, preferably 600 to 1200. The method according to any one of claims 1 to 8

10. Step 2) is carried out using a fixed-bed reactor, the first reaction zone is arranged above the second reaction zone, and preferably, the first reaction zone and the second reaction zone are separated by an inert material. The method according to any one of claims 1 to 9.

11. A method for producing adamantane, comprising: a step of subjecting a liquid feed stream containing tetrahydrodicyclopentadiene, especially endo-tetrahydrodicyclopentadiene, to an isomerization reaction by contacting it with an isomerization catalyst under a hydrogen atmosphere. The isomerization catalyst is 450 to 900 m ２ / g, preferably 600 to 800 m ２ / g of specific surface area, 0.25 to 0.5 cm ３ / g, preferably 0.35 to 0.45 cm ３ / g of pore volume, 0.02 to 0.10 cm ３ / g, preferably 0.07 to 0.09 cm ３ / g of mesopore volume, a metal-modified molecular sieve catalyst having an amount of strong acid of 150 to 850 μmol / g, preferably 370 to 700 μmol / g. a reaction temperature of 181 to 300 °C, preferably 200 to 260 °C. The reaction pressure is 0.1 to 3.0 MPa, preferably 0.5 to 1.0 MPa. Preferably, in the reaction, the mass space velocity of the end-tetrahydrodicyclopentadiene is 0.2 to 5 h －１ , preferably 0.5 to 2 h －１ and the volume ratio of hydrogen to the liquid is 100 to 3000, preferably 600 to 1200.

12. The isomerization catalyst includes a molecular sieve and a modified metal supported on the molecular sieve. The modified metal is selected from Pd, Pt, Au, Ru, Rh, Ni, or a combination thereof. The molecular sieve is a Y-type molecular sieve, preferably selected from HY, USY, REHY, or a combination thereof, more preferably selected from HY, HUSY, REHY, or a combination thereof. Preferably, based on the total mass of the isomerization catalyst, the content of Ni in the isomerization catalyst is 1 to 20%, preferably 3 to 15%, more preferably 3 to 10%. and / or the total content of Pd, Pt, Au, Ru, and Rh is 0.05 to 5.0%, preferably 0.1 to 1.0%, more preferably 0.2 to 0.5%. More preferably, the molecular sieve has an Na content of less than 0.5%, preferably less than 0.2%, based on the mass of the molecular sieve. ２ The method according to claim 11, having an O content.

13. The isomerization catalyst is I) a step of modifying the Y-type molecular sieve by using an ammonium fluorosilicate solution, wherein the mass ratio of the ammonium fluorosilicate to the Y-type molecular sieve is 0.1 to 0.

3. The Y-type molecular sieve is preferably a hydrogen-type molecular sieve, more preferably selected from HY, HUSY, REHY, or combinations thereof, step; and, II) supporting the reforming metal on the reformed molecular sieve obtained in step I), firing, and reducing in a reducing atmosphere to obtain the isomerization catalyst; prepared by a method comprising: Preferably, the supporting step in step II) is achieved by impregnating the reformed molecular sieve with a solution of a precursor of the reforming metal and optionally drying; The method according to claim 11 or 12, wherein the precursor is preferably a salt of the reforming metal.

14. The conditions of the reforming treatment in step I) include a treatment temperature of 30 to 100°C, preferably 50 to 80°C, and a treatment time of 0.5 to 5 hours, preferably 0.5 to 3 hours; Preferably, the concentration of the ammonium fluorosilicate solution is 0.02 to 2 mol / L, preferably 0.05 to 0.3 mol / L, according to the method of claim 13.

15. The feed stream includes end-tetrahydrodicyclopentadiene and a reaction solvent selected from hydrocarbons or halogenated hydrocarbon solvents having a boiling point of 40 to 300°C; The hydrocarbon or halogenated hydrocarbon solvent is preferably selected from C6-C10 hydrocarbons, more preferably selected from cyclohexane, methylcyclohexane, exo-tetrahydrodicyclopentadiene, or combinations thereof; Preferably, the mass concentration of end-tetrahydrodicyclopentadiene in the feed stream is 10 to 80%, more preferably 30 to 60%, according to any one of claims 11 to 14.

16. The isomerization reaction is preferably carried out in a fixed bed reactor within a reactor selected from a fixed bed, moving bed, fluidized bed, slurry bed, or combinations thereof, according to any one of claims 11 to 15.

17. Before performing the isomerization reaction, the method further includes a step of pretreating the liquid feed stream containing tetrahydrodicyclopentadiene with an adsorbent. Preferably, the adsorbent is selected from activated clay, NaY molecular sieve, X-type molecular sieve, activated carbon, or a combination thereof, and more preferably, it is selected from activated clay, NaY molecular sieve, or a combination thereof. More preferably, the conditions of the pretreatment are a temperature from normal temperature to 60°C, a pressure of 0.0 to 0.5 MPa, and an end-tetrahydrodicyclopentadiene mass space velocity of 0.1 to 10.0 h －１ , preferably 0.2 to 1 h －１ , and the method according to any one of claims 11 to 16.

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