An epoxidation catalyst, its preparation and use

Abstract

The present application relates to an epoxidation catalyst, a preparation method and use thereof, the epoxidation catalyst comprising a carrier and an epoxidation active catalytic layer supported on the carrier; the epoxidation active catalytic layer comprises a transition metal layer; the carrier comprises a support material and a magnetic heat-conductive layer coated outside the support material; the magnetic heat-conductive layer contains a magnetic material and a heat-conductive ceramic material; the magnetic material comprises a magnetic particle inner core and a porous oxide shell coated outside the magnetic particle inner core. The preparation method of the epoxidation catalyst provided by the present application is simple, the single-batch production capacity is large, the preparation efficiency is relatively high, and the obtained epoxidation catalyst has good catalytic effect for olefin epoxidation reaction.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of catalyst preparation, in particular to an epoxidation catalyst and a preparation method and use thereof. BACKGROUND

[0002] Ethylbenzene co-oxidation process (PO / SM) using ethylbenzene hydrogen peroxide (EBHP) as oxidant and cumene hydrogen peroxide (CHP) process using cumene hydrogen peroxide (CHP) as oxidant are two important processes for producing propylene oxide (PO), which overcome the shortcomings of chlorohydrination method such as severe corrosion and large amount of sewage, and have the advantages of low product cost and small environmental pollution. The catalysts used in the above two processes are Ti-Si molecular sieves or Ti-SiO2 composite oxides with a pore size of 3 nm or more. Research has found that the service life of the catalyst is ≤0.5 years, and the annual demand for catalyst for a set of industrial device with an annual output of 280,000 tons of PO is ≥200 tons, so the amount of catalyst used is very large.

[0003] CN1250775A discloses a method for producing propylene oxide, and CN1248579A discloses a method for preparing propylene oxide. In the above studies, ethylbenzene hydrogen peroxide is used as an oxidant, and Ti-MCM-41 molecular sieve is used as a catalyst for the process of propylene epoxidation to produce propylene oxide. US5783167A discloses a method for synthesizing Ti-MCM-41 mesoporous material containing titanium by hydrothermal method. CN106582809A discloses an olefin epoxidation catalyst and a preparation method thereof. The catalyst in the method is a modified titanium-silicon molecular sieve, and the pore size of the molecular sieve is 10 nm or more. However, the above methods all use hydrothermal method to synthesize the catalyst. The catalyst is prepared by using a template agent with a specific molecular weight and structure under high-temperature hydrothermal conditions in a reaction kettle. After the molecular sieve is synthesized by hydrothermal method, it needs to be dried, demolded and calcined to obtain the molecular sieve raw powder, and then the epoxidation catalyst is prepared by molding. The synthesis process of the above method is complex, a large amount of template agent is needed in the synthesis process, which leads to high preparation cost of the catalyst, and the molding process is complex, which limits its large-scale production and application in industry.

[0004] US4021454A and CN110252272A, etc. disclosed that using macroporous SiO2 as a carrier, a titanium source was loaded on the surface of the carrier by gas deposition or liquid immersion method, and a titanium-silicon catalyst was obtained through drying, calcination and silanization treatment. However, the above-mentioned researches have the following problems in the preparation of catalyst by gas deposition method: (1) the conventional fixed bed reactor is used for intermittent operation, and the bed temperature of the reactor needs to be frequently switched between steps. Since the macroporous SiO2 has low density and low thermal conductivity, the time for heating and cooling the carrier bed and reaching temperature balance is very long, which leads to long catalyst preparation time and limits its large-scale production; (2) the intermittent converter is used to prepare the catalyst, which has low space utilization of the converter reactor, serious corrosion at the rotating part, and the reactant vapor is easy to penetrate from the upper cavity of the converter, which leads to low raw material utilization, difficult treatment of tail gas and other problems.

[0005] In summary, the existing preparation method of epoxidation catalyst has the problems of complex preparation process, low preparation efficiency, low raw material utilization, and poor catalytic effect, etc. Therefore, it is of great significance to provide a method which can solve the above problems and realize industrial large-scale production. SUMMARY

[0006] In view of the above problems, the purpose of the present application is to provide an epoxidation catalyst and its preparation method and use. Compared with the prior art, the preparation method of the epoxidation catalyst provided by the present application is simple, has large single-batch production capacity, and has high preparation efficiency. The obtained epoxidation catalyst has good catalytic effect for olefin epoxidation reaction.

[0007] To achieve the purpose of the present application, the following technical solutions are adopted:

[0008] In a first aspect, the present application provides an epoxidation catalyst, which comprises a carrier and an epoxidation active catalytic layer loaded on the carrier.

[0009] The epoxidation active catalytic layer comprises a transition metal layer.

[0010] The carrier comprises a support material and a magnetic heat-conductive layer coated outside the support material.

[0011] The magnetic heat-conductive layer contains a magnetic material and a heat-conductive ceramic material.

[0012] The magnetic material comprises a magnetic particle core and a porous oxide shell coated outside the magnetic particle core.

[0013] In the present application, the outer cover of the carrier is coated with a magnetic heat-conductive layer, and the magnetic heat-conductive layer is designed to contain magnetic material and heat-conductive ceramic material. The magnetic material can make the carrier have good ferromagnetism, and can quickly raise and lower the temperature through its electromagnetic induction. At the same time, the heat-conductive ceramic material can further improve the heat conductivity of the carrier, solving the problem of slow temperature rising and falling rate of conventional porous oxide carrier due to low thermal conductivity, thereby improving the production efficiency of the catalyst. The porous oxide shell wrapped on the surface of the magnetic particle core can make the epoxy active catalytic layer more easily deposited. The epoxidation catalyst provided by the present application not only has high preparation efficiency, but also can realize efficient and uniform deposition of the epoxy active catalytic layer due to the uniform temperature distribution of the carrier bed during the preparation process. The obtained epoxidation catalyst has a high number and dispersion of active centers, thereby greatly improving the catalytic activity of the epoxidation catalyst.

[0014] Preferably, the magnetic particle core contains any one or a combination of at least two of Fe3O4, NbFeB alloy, AlNiCo alloy or AlFeCo alloy, wherein a typical but non-limiting combination includes a combination of Fe3O4 and NbFeB alloy or a combination of Fe3O4, NbFeB alloy and AlNiCo alloy.

[0015] In the present application, the magnetic particle core is preferably prepared by a gas atomization method, which can help to obtain a catalyst with uniform particle size.

[0016] Preferably, the porous oxide shell contains any one or a combination of at least two of silicon dioxide, aluminum sesquioxide or titanium dioxide, wherein a typical but non-limiting combination includes a combination of silicon dioxide and aluminum sesquioxide or a combination of aluminum sesquioxide and titanium dioxide.

[0017] Preferably, the heat-conductive ceramic material includes any one or a combination of at least two of beryllium oxide, aluminum nitride, silicon carbide, silicon nitride or polycrystalline diamond ceramic, wherein a typical but non-limiting combination includes a combination of beryllium oxide and aluminum nitride or a combination of silicon carbide and silicon nitride.

[0018] Preferably, the transition metal layer includes a titanium layer.

[0019] Preferably, the support material includes silica microspheres.

[0020] Preferably, the average diameter of the silica microspheres is 0.4-0.6mm, for example, it can be 0.4mm, 0.42mm, 0.46mm, 0.48mm, 0.5mm, 0.52mm, 0.54mm, 0.56mm, 0.58mm or 0.6mm, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0021] Preferably, the shape of the carrier comprises any one of a sphere, an ellipsoid, a cylinder or a torus, preferably a sphere or a torus.

[0022] Preferably, the diameter of the carrier is 2-5mm, for example, can be 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm, but not limited to the listed values, other values not listed in the value range are also applicable.

[0023] Preferably, the mass percentage of the heat-conducting ceramic material in the carrier is 15-30%, for example, can be 15%, 16%, 18%, 20%, 22%, 24%, 26%, 28% or 30%, but not limited to the listed values, other values not listed in the value range are also applicable.

[0024] In the present application, the mass percentage of the heat-conducting ceramic material in the carrier is preferably controlled within a certain range, which can greatly improve the thermal conductivity of the carrier, while avoiding the influence of the carrier strength due to the high addition ratio.

[0025] Preferably, the mass percentage of the magnetic particle core in the carrier is 15-25%, for example, can be 15%, 16%, 18%, 20%, 22%, 24% or 25%, but not limited to the listed values, other values not listed in the value range are also applicable.

[0026] In the present application, the mass percentage of the magnetic particle core in the carrier is preferably controlled within a certain range, which can realize the self-heating of the carrier under the condition of electromagnetic induction heating, and improve the heating rate of the carrier.

[0027] Preferably, the thermal conductivity of the carrier is 80-150W / (m·K), for example, can be 80W / (m·K), 85W / (m·K), 90W / (m·K), 95W / (m·K), 100W / (m·K), 105W / (m·K), 110W / (m·K), 115W / (m·K), 120W / (m·K), 125W / (m·K), 130W / (m·K), 135W / (m·K), 140W / (m·K), 145W / (m·K) or 150W / (m·K), but not limited to the listed values, other values not listed in the value range are also applicable.

[0028] Preferably, the mass percentage of the carrier in the catalyst is 93-97%, for example, can be 93%, 94%, 95%, 96% or 97%, but not limited to the listed values, other values not listed in the value range are also applicable.

[0029] Preferably, the pore size of the carrier is 5-15 nm, for example, can be 5 nm, 6 nm, 8 nm, 10 nm, 12 nm or 15 nm, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0030] Preferably, the specific surface area of the carrier is 200-500 m 2 / g, for example, can be 200 m 2 / g, 250 m 2 / g, 300 m 2 / g, 350 m 2 / g, 400 m 2 / g, 450 m 2 / g, or 500 m 2 / g, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0031] Preferably, the water content of the carrier is ≤1 wt%, for example, can be 1 wt%, 0.9 wt% or 0.8 wt%, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0032] In a second aspect, the present application provides a preparation method of the epoxidation catalyst as described in the first aspect of the present application, the preparation method comprising the following steps:

[0033] (1) mixing a magnetic powder, ethanol, water and ammonia water to disperse, to obtain a dispersion liquid; then adding a porous oxide precursor dropwise to the dispersion liquid to react, and then separating to obtain a reaction product, and then sequentially washing, drying and calcining the reaction product to obtain a magnetic particle coated with a porous oxide:

[0034] (2) mixing the magnetic particle coated with a porous oxide obtained in step (1), a heat-conducting ceramic material and a binder to obtain a mixed powder; using the mixed powder to coat a support material, and then sequentially drying and calcining to obtain a carrier;

[0035] (3) packing the carrier obtained in step (2) into a carrier bed, and then sequentially performing active center vapor deposition, high-temperature treatment, water treatment and silanization treatment, and then cooling to obtain an epoxidation catalyst.

[0036] In the present application, firstly, the magnetic powder-containing dispersion liquid and the porous oxide precursor are reacted to obtain the porous oxide-coated magnetic particles; then, the porous oxide-coated magnetic particles and the heat-conducting ceramic material are used to coat the support material to obtain the carrier; and then, the active center vapor deposition, high-temperature treatment, water treatment and silanization treatment are used to deposit the epoxy active catalytic layer on the carrier, so that the obtained catalyst has higher efficiency of depositing the epoxy active catalytic layer and good catalytic activity.

[0037] In the present application, the magnetic powder is pretreated before mixing in step (1), and the purpose of the pretreatment is to form a rough surface on the magnetic powder to facilitate the hydrolysis and coating of the surface oxide. The pretreatment is generally acid treatment, mainly including: mixing the magnetic powder and the acid liquid for ultrasonic treatment, and then sequentially separating and washing; the acid liquid can be any acid liquid commonly used in the art for pretreating the magnetic powder, for example, it can be hydrochloric acid with a concentration of 0.1-0.3 mol / L, and the ultrasonic treatment time is generally ≥ 30 min.

[0038] In the present application, the separation is generally performed by magnetic separation.

[0039] In the present application, after the epoxidation catalyst is prepared, the catalyst bed is cooled to room temperature, the product is transferred from the reactor to the product bin by a negative pressure suction system, and the final epoxidation catalyst product is obtained after screening.

[0040] Preferably, the porous oxide precursor in step (1) includes any one or a combination of at least two of silicate, aluminate or titanate, for example, a combination of silicate and aluminate or a combination of aluminate and titanate.

[0041] Preferably, the magnetic powder includes any one or a combination of at least two of Fe3O4, NbFeB alloy, AlNiCo alloy or AlFeCo alloy, and a typical but non-limiting combination includes a combination of Fe3O4 and NbFeB alloy or a combination of AlNiCo alloy and AlFeCo alloy.

[0042] Preferably, the mass ratio of the porous oxide precursor to the magnetic powder is 1:(0.8-1), for example, it can be 1:0.8, 1:0.85, 1:0.9, 1:0.95 or 1:1, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0043] Preferably, the mass ratio of the ethanol to water is 1 : (3-5), for example, it can be 1 :3, 1 :3.2, 1 :3.4, 1 :3.5, 1 :3.8, 1 :4, 1 :4.2, 1 :4.4, 1 :4.6, 1 :4.8 or 1 :5, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0044] Preferably, the mass percentage of the magnetic powder in the dispersion is 1-2%, for example, it can be 1%, 1.2%, 1.4%, 1.6%, 1.8% or 2%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0045] Preferably, the dispersion time is 1-1.5h, for example, it can be 1h, 1.1h, 1.2h, 1.3h, 1.4h or 1.5h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0046] Preferably, the dispersion is carried out under the condition of ultrasonic.

[0047] Preferably, the pH value of the dispersion is 11-13, for example, it can be 11, 11.5, 12, 12.5 or 13, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0048] In the present application, the mass concentration of the ammonia water is generally 25%.

[0049] Preferably, the reaction time is 5-7h, for example, it can be 5h, 5.5h, 6h, 6.5h or 7h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0050] Preferably, the drying temperature in step (1) is 100-140℃, for example, it can be 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃ or 140℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0051] Preferably, the drying time in step (1) is 2-4h, for example, it can be 2h, 2.5h, 3h, 3.5h or 4h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0052] Preferably, the calcination temperature in step (1) is 500-600℃, for example, it can be 500℃, 520℃, 540℃, 560℃, 580℃ or 600℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0053] Preferably, the roasting in step (1) is performed for 3-5 hours, for example, it can be 3 hours, 3.5 hours, 4 hours, 4.5 hours or 5 hours, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0054] Preferably, the mass percentage of the heat-conducting ceramic material in the mixed powder in step (2) is 15-30%, for example, it can be 15%, 16%, 18%, 20%, 22%, 24%, 26%, 28% or 30%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0055] Preferably, the mass percentage of the binder in the mixed powder is 2-5%, for example, it can be 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0056] In the present application, the binder can be any binder used in the field for molding, for example, it can be any one of cellulose, PVA, PEG or gum arabic, or a combination of at least two thereof.

[0057] Preferably, the coating is performed in a coating machine.

[0058] Preferably, an auxiliary agent is added during the coating.

[0059] Preferably, the auxiliary agent comprises a water solution of silica gel.

[0060] Preferably, the mass percentage of SiO2 in the water solution of silica gel is 8-12%, for example, it can be 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5% or 12%, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0061] Preferably, the drying in step (2) is performed at a temperature of 100-120°C, for example, it can be 100°C, 102°C, 104°C, 106°C, 108°C, 110°C, 112°C, 114°C, 116°C, 118°C or 120°C, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0062] Preferably, the drying in step (2) is performed for 3-5 hours, for example, it can be 3 hours, 3.5 hours, 4 hours, 4.5 hours or 5 hours, but is not limited to the listed values, and other values not listed in the range are also applicable.

[0063] Preferably, the temperature of the calcination in step (2) is 500-700℃, for example, it can be 500℃, 520℃, 540℃, 560℃, 580℃, 600℃, 620℃, 640℃, 660℃, 680℃ or 700℃, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0064] Preferably, the time of the calcination in step (2) is 3-5h, for example, it can be 3h, 3.5h, 4h, 4.5h or 5h, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0065] Preferably, the process of the active center vapor deposition in step (3) comprises: first heating the carrier bed layer to a first reaction temperature, holding and introducing a first reaction gas to obtain a first carrier bed layer.

[0066] Preferably, the first reaction gas comprises a mixture of titanium compound vapor and nitrogen.

[0067] Preferably, the volume percentage of titanium compound vapor in the first reaction gas is 5-15%, for example, it can be 5%, 6%, 8%, 10%, 12%, 14% or 15%, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0068] Preferably, the titanium compound vapor comprises any one or a combination of at least two of titanium tetrafluoride, titanium tetrachloride, titanium tetrabromide, tetraethyl titanate, tetrapropyl titanate or tetrabutyl titanate, wherein a typical but non-limiting combination includes a combination of titanium tetrafluoride and titanium tetrachloride or a combination of titanium tetrabromide and tetraethyl titanate, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0069] Preferably, the first reaction temperature is 150-300℃, for example, it can be 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 240℃, 260℃, 280℃ or 300℃, but not limited to the listed values, other values not listed in the range of values are also applicable.

[0070] Preferably, the process of the high-temperature treatment comprises: second heating the first carrier bed layer to a second reaction temperature, holding and introducing a second reaction gas to obtain a second carrier bed layer.

[0071] Preferably, the second reaction gas comprises nitrogen.

[0072] Preferably, the purity of the second reaction gas is ≥ 99.5%, for example, it can be 99.95%, 99.96%, 99.97%, or 99.98%, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0073] Preferably, the second reaction temperature is 500-800℃, for example, it can be 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, or 800℃, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0074] Preferably, the process of water treatment includes: performing a first temperature reduction of the second carrier bed layer to a third reaction temperature, holding the temperature, and introducing a third reaction gas to obtain a third carrier bed layer.

[0075] Preferably, the third reaction gas includes a mixture of water vapor and nitrogen.

[0076] Preferably, the volume percentage content of water vapor in the third reaction gas is 5-10%, for example, it can be 5%, 6%, 7%, 8%, 9%, or 10%, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0077] Preferably, the third reaction temperature is 250-400℃, for example, it can be 250℃, 260℃, 280℃, 300℃, 320℃, 340℃, 360℃, 380℃, or 400℃, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0078] Preferably, the process of silylation treatment includes: performing a second temperature reduction of the third carrier bed layer to a fourth reaction temperature, holding the temperature, and introducing a fourth reaction gas to obtain an epoxidation catalyst.

[0079] Preferably, the fourth reaction gas includes a mixture of an organic silane vapor and nitrogen.

[0080] Preferably, the organic silane vapor includes any one or a combination of at least two of hexamethyldisilazane, hexamethylchlorosilazane, heptamethylchlorosilazane, trimethylchlorosilane, dimethylchlorosilane, tetramethyldisilazane, dimethyldiethoxysilane, trimethylmethoxysilane, dimethyldimethoxysilane, or trimethylethoxysilane, for example, it can be a combination of hexamethyldisilazane and hexamethylchlorosilazane or a combination of trimethylchlorosilane and dimethylchlorosilane.

[0081] Preferably, the volume percentage of the organic silane vapor in the fourth reaction gas is 10-25%, for example, it can be 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24% or 25%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0082] Preferably, the fourth reaction temperature is 150-300℃, for example, it can be 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 240℃, 260℃, 280℃ or 300℃, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0083] Preferably, during the first temperature rise, the second temperature rise, the first temperature drop and the second temperature drop, the temperature change rate of the carrier bed is independently 2-5℃ / min, for example, it can be 2℃ / min, 2.5℃ / min, 3℃ / min, 3.5℃ / min, 4℃ / min, 4.5℃ / min or 5℃ / min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0084] In the present application, the temperature change rate of the carrier bed is preferably controlled within a certain range, which can achieve rapid temperature rise and drop and ensure the loading amount of the epoxy active catalytic layer.

[0085] Preferably, the temperature difference between different parts of the carrier bed during the holding is ≤8℃, for example, it can be 8℃, 7℃, 6℃, 5℃, 4℃, 3℃, 2℃ or 1℃, but is not limited to the listed values, and other values not listed in the value range are also applicable, preferably ≤5℃.

[0086] In the present application, taking center vapor deposition as an example, the temperature difference between different parts of the carrier bed during the holding is preferably controlled within a certain range, which can make the deposition reaction of the active center and the carrier proceed uniformly throughout the carrier bed, improve the uniformity of the epoxy active catalytic layer, and the number and dispersion of the active center are higher, thereby improving the catalytic activity of the catalyst.

[0087] Preferably, the holding time is 2-6h, for example, it can be 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h or 6h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0088] Preferably, the carrier bed in step (3) is filled in the reactor, generally at the bottom of the reactor.

[0089] Preferably, the packing volume of the carrier bed accounts for ≥80% of the reactor volume, for example, it can be 80%, 81%, 82%, 83%, 84% or 85%, but is not limited to the listed values, and other unlisted values within the value range are also applicable.

[0090] Preferably, the reactor comprises a kettle body; the kettle body is cylindrical; at least one set of baffles is arranged in the kettle body in a direction perpendicular to the axial direction of the kettle body; the baffles comprise at least two fins at the same height; at least two cooling medium channels are arranged in the kettle body in a direction parallel to the axial direction of the kettle body; the cooling medium channels pass through the inside of the fins; and an induction coil is arranged on the outer side wall of the kettle body in a circumferential direction.

[0091] In the present application, the structure of the reactor is preferably controlled to arrange a medium-frequency induction system on the outer side of the kettle body, including arranging an induction coil on the outer side wall of the kettle body in a circumferential direction, so as to control the heating rate of the kettle body shell, the internal baffles and the carrier bed by adjusting the power of the induction coil; and a separate circulating cooling system is arranged in the kettle, including a separate cooling medium channel, so as to realize rapid heat removal of the cooling medium (such as lithium bromide or freon) and rapid cooling of the internal baffles of the reactor.

[0092] Preferably, the top of the kettle body is provided with a tail gas pipeline.

[0093] Preferably, the bottom of the kettle body is provided with a gas phase inlet pipeline.

[0094] Preferably, the inlet of the cooling medium channel is connected with the outlet of the cooling circulating pump.

[0095] Preferably, the outlet of the cooling medium channel is connected with the inlet of the cooling circulating pump.

[0096] In the present application, the circulating cooling system is composed of the cooling circulating pump and the cooling medium channel, so as to realize rapid circulation and heat removal of the cooling medium in the kettle body, thereby realizing rapid cooling of the internal baffles of the reactor and rapid cooling of the carrier bed.

[0097] Preferably, the baffles and the kettle body are both ferromagnetic metal materials.

[0098] In the present application, by controlling the baffles and the kettle body to be ferromagnetic metal materials, the baffles are welded on the inner wall of the kettle body, so as to form a medium-frequency induction system with the induction coil, the kettle body shell and the baffles, and to achieve the effect of rapid heating of the carrier bed by controlling the power of the induction coil.

[0099] Preferably, the temperature change rate of the baffle and the kettle body during the first temperature rising, the second temperature rising, the first temperature falling and the second temperature falling is independently 2-5℃ / min, for example, it can be 2℃ / min, 3℃ / min, 4℃ / min or 5℃ / min, but is not limited to the listed values, other values not listed in the value range are also applicable, preferably 3-5℃ / min.

[0100] As a preferred technical scheme of the second aspect of the present application, the preparation method comprises the following steps:

[0101] (1) mixing the magnetic powder, ethanol, water and ammonia water, and dispersing under ultrasonic condition for 1-1.5h to obtain a dispersion liquid, the pH value of the dispersion liquid is 11-13; then adding porous oxide precursor dropwise into the dispersion liquid to react for 5-7h, the mass ratio of the porous oxide precursor to the magnetic powder is 1:(0.8-1), the mass ratio of the ethanol to the water is 1:(3-5), the mass percentage of the magnetic powder in the dispersion liquid is 1-2%, and then separating to obtain a reaction product; washing the reaction product, and then drying at 100-140℃, and then calcining at 500-600℃ for 3-5h to obtain the magnetic particles coated with porous oxide;

[0102] (2) mixing the magnetic particles coated with porous oxide obtained in step (1), the heat-conducting ceramic material and the binder to obtain a mixed powder, the mass percentage of the heat-conducting ceramic material in the mixed powder is 15-30%, and the mass percentage of the binder is 2-5%; using the mixed powder to coat the support material in a coating machine, adding SiO2 aqueous solution with a mass concentration of 8-12% in the coating process, and then drying at 100-120℃ for 3-5h, and then calcining at 500-700℃ for 3-5h to obtain a carrier;

[0103] (3) packing the carrier obtained in step (2) into a carrier bed layer, and performing first temperature rising of the carrier bed layer to 150-300℃, and then introducing the mixed gas of titanium compound vapor and nitrogen, wherein the volume percentage of the titanium compound vapor is 5-15%, and the titanium compound vapor includes any one or a combination of at least two of titanium tetrafluoride, titanium tetrachloride, titanium tetrabromide, tetraethyl titanate, tetrapropyl titanate or tetrabutyl titanate, to obtain a first carrier bed layer;

[0104] performing second temperature rising of the first carrier bed layer to 500-800℃, and then introducing nitrogen with a purity of ≥99.5% to obtain a second carrier bed layer;

[0105] the second carrier bed is subjected to a first temperature reduction to 250-400℃, and then is kept at the temperature and is fed with a mixed gas of water vapor and nitrogen, wherein the volume percentage of the water vapor is 5-10%, to obtain a third carrier bed;

[0106] the third carrier bed is subjected to a second temperature reduction to 150-300℃, and then is kept at the temperature and is fed with a mixed gas of organosilane vapor and nitrogen, wherein the volume percentage of the organosilane vapor is 10-25%, and the organosilane vapor includes any one or a combination of at least two of hexamethyldisilazane, hexamethylchlorosilazane, heptamethylchlorosilazane, trimethylchlorosilane, dimethylchlorosilane, tetramethyldisilazane, dimethyldiethoxysilane, trimethylmethoxysilane, dimethyldimethoxysilane or trimethylethoxysilane, to obtain an epoxidation catalyst;

[0107] In the process of the first temperature increase, the second temperature increase, the first temperature reduction and the second temperature reduction, the temperature change rate of the carrier bed is independently 2-5℃ / min, the temperature difference between different parts of the carrier bed is ≤8℃ in the process of keeping at the temperature, and the time of keeping at the temperature is 2-6h.

[0108] The carrier bed is filled in the bottom of a reactor, and the filling volume of the carrier bed accounts for ≥80% of the volume of the reactor, the reactor includes a kettle body, the kettle body is cylindrical, at least one set of baffles is arranged in the kettle body in a direction perpendicular to the axial direction of the kettle body, the baffles include at least two fins at the same height, at least two cooling medium channels are arranged in the kettle body in a direction parallel to the axial direction of the kettle body, the cooling medium channels penetrate the inside of the fins, an inductive coil is arranged on the outer side wall of the kettle body in a circumferential direction, a tail gas pipeline is arranged on the top of the kettle body, a gas phase inlet pipeline is arranged on the bottom of the kettle body, the inlet of the cooling medium channel is connected with the outlet of a cooling circulating pump, and the outlet of the cooling medium channel is connected with the inlet of the cooling circulating pump, the baffles and the kettle body are both made of a ferromagnetic metal material, and in the process of the first temperature increase, the second temperature increase, the first temperature reduction and the second temperature reduction, the temperature change rate of the baffles and the kettle body is independently 2-5℃ / min.

[0109] In a third aspect, the present application provides a use of the epoxidation catalyst as described in the first aspect of the present application in a liquid phase epoxidation reaction of an olefin and an oxidant.

[0110] The epoxidation catalyst provided by the present application has high catalytic activity in the liquid phase epoxidation reaction of an olefin and an oxidant, and can be used in the reaction of propylene and an oxidant to prepare propylene oxide.

[0111] In the present application, the temperature, pressure, molar ratio of propylene to oxidant, mass space velocity of oxidant, purity of propylene, moisture content of the system, etc. of the reaction for preparing propylene oxide can adopt the common conditions for preparing propylene oxide reaction in the art, for example, the temperature of the reaction is controlled to be 40-120℃, the pressure is 2-4.5 MPa, the molar ratio of propylene to oxidant is (3-10):1, the mass space velocity of oxidant is 1-5 h -1 , the purity of propylene is >99.5%, and the moisture content of the system is <100 ppm.

[0112] Preferably, the olefins include any one or a combination of at least two of C3-C 10 linear olefins, C3-C 10 isoolefins, C6-C 16 cyclic olefins, or C6-C 16 aromatic olefins, wherein a typical but non-limiting combination includes C3-C 10 linear olefins and C3-C 10 isoolefins, or C3-C 10 isoolefins and C6-C 16 cyclic olefins.

[0113] Preferably, the oxidant includes an organic peroxide.

[0114] Preferably, the organic peroxide includes any one or a combination of at least two of t-butyl hydroperoxide, ethylbenzene hydroperoxide, or cumyl hydroperoxide.

[0115] Compared with the prior art, the present application has the following beneficial effects:

[0116] (1) The epoxidation catalyst provided by the present application can make the carrier itself heat up through electromagnetic induction by controlling the carrier to have ferromagnetism and good thermal conductivity, solving the problem of slow heating and cooling rate of the conventional porous oxide carrier due to low thermal conductivity, thereby greatly improving the production efficiency of the process of depositing the active catalytic layer of the catalyst, and the catalytic activity of the catalyst can also be greatly improved.

[0117] (2) The preparation method provided by the present application can achieve rapid heating of the carrier bed layer by controlling the power of the induction coil to control the rapid heating of the carrier bed layer, and can achieve rapid cooling of the reactor partition plate and the carrier bed layer by designing a circulating cooling system composed of a cooling circulating pump and a cooling medium channel to realize rapid circulation of the cooling medium in the kettle body to remove heat, thereby not only improving the preparation efficiency of the catalyst, but also improving the catalytic activity of the catalyst.

[0118] (3) The epoxidation catalyst provided by the application has high catalytic activity in liquid phase epoxidation reaction of olefins and oxidants. Taking the preparation of propylene oxide by propylene epoxidation as an example, when EBHP is used as the oxidant, the conversion rate of EBHP can reach 92.6% or more, and the selectivity of propylene oxide can reach 84.2% or more; when CHP is used as the oxidant, the conversion rate of CHP can reach 93.6% or more, and the selectivity of propylene oxide can reach 85.5% or more; under the more optimal conditions, when EBHP is used as the oxidant, the conversion rate of EBHP can reach 98.9% or more, and the selectivity of propylene oxide can reach 93.6% or more; when CHP is used as the oxidant, the conversion rate of CHP can reach 99.3% or more, and the selectivity of propylene oxide can reach 94.2% or more. BRIEF DESCRIPTION OF DRAWINGS

[0119] Figure 1 The structure diagram of the reactor and the carrier bed layer filled in the reactor according to the embodiment 1 of the application is shown in the figure.

[0120] Figure 2 The top view of the reactor and the carrier bed layer filled in the reactor according to the embodiment 1 of the application is shown in the figure.

[0121] In the figure, 1 is an induction coil, 2 is a carrier bed layer, 3 is a partition, 4 is a cooling medium channel, 5 is a gas phase inlet pipeline, 6 is a tail gas pipeline, 7 is a cooling circulating pump, 8 is a kettle body, and 9 is a fin. DETAILED DESCRIPTION

[0122] The technical solutions of the application will be further described by specific embodiments. It should be understood by those skilled in the art that the embodiments are only used to help understand the application and should not be regarded as specific limitations to the application.

[0123] In one specific embodiment, the preparation method of the epoxidation catalyst provided by the application includes the following steps: (1) mixing magnetic powder, ethanol, water and ammonia water to disperse, to obtain a dispersion liquid; then adding porous oxide precursors dropwise into the dispersion liquid to react, and then separating to obtain a reaction product, and then sequentially washing, drying and calcining the reaction product to obtain magnetic particles coated with porous oxides; (2) mixing the magnetic particles coated with porous oxides obtained in step (1), a heat-conducting ceramic material and a binder to obtain a mixed powder; using the mixed powder to coat a support material to obtain a carrier; (3) filling the carrier obtained in step (2) into a carrier bed layer 2, and then sequentially performing active center vapor deposition, high-temperature treatment, water treatment and silanization treatment, and then cooling to obtain an epoxidation catalyst.

[0124] In step (3), the carrier bed layer 2 is filled in a reactor, and the structure diagram of the reactor and the carrier bed layer is shown in the figure. Figure 1As shown, the top view is as shown in the figure Figure 2 As shown, the reactor comprises a kettle body 8, the kettle body 8 is cylindrical, 5 groups of baffles 3 are arranged in the kettle body 8 in the direction perpendicular to the axial direction of the kettle body 8, the baffle 3 comprises 4 fins 9 at the same height, 4 cooling medium channels 4 are arranged in the kettle body 8 in the direction parallel to the axial direction of the kettle body 8, the cooling medium channels 4 pass through the inside of the fin 9, and an induction coil 1 is arranged on the outer wall of the kettle body 8 in a circumferential direction; the baffle 3 and the kettle body 8 are both ferromagnetic metal materials, and are specifically 2205 alloy.

[0125] In the application, by controlling that the baffle 3 and the kettle body 8 are both ferromagnetic metal materials, the baffle 3 is welded on the inner wall of the kettle body 8, the induction coil 1, the shell of the kettle body 8 and the baffle 3 form a medium frequency induction system, and the power of the induction coil 1 is controlled to achieve the effect of rapidly heating the carrier bed layer 2.

[0126] The kettle body 8 is provided with a tail gas pipeline 6 at the top, the kettle body 8 is provided with a gas phase inlet pipeline 5 at the bottom, the inlet of the cooling medium channel 4 is connected with the outlet of the cooling circulating pump 7, and the outlet of the cooling medium channel 4 is connected with the inlet of the cooling circulating pump 7.

[0127] In the application, the cooling circulating pump 7 and the cooling medium channel 4 form a circulating cooling system, the cooling medium can be rapidly circulated and removed in the kettle body 8, so that the baffle 3 in the reactor can be rapidly cooled, and the carrier bed layer 2 can be rapidly cooled.

[0128] In the application, the power of the induction coil 1 is controlled by a medium frequency induction device, the medium frequency induction device used in the following embodiment is produced by Xi'an Lan Hui Electromechanical Co., Ltd., and the model is LH-02, and the coating machine used in the following embodiment is produced by Zibo Shike Pharmaceutical Co., Ltd., and the instrument model is WKY-600.

[0129] Example 1

[0130] The embodiment provides an epoxidation catalyst, which comprises a carrier and an epoxidation active catalytic layer supported on the carrier, the epoxidation active catalytic layer is a titanium layer, the carrier comprises a support material and a magnetic heat-conductive layer coated outside the support material, the magnetic heat-conductive layer contains a magnetic material and a heat-conductive ceramic material, the magnetic material comprises a magnetic particle inner core and a porous oxide shell coated outside the magnetic particle inner core, the magnetic particle inner core is an Fe3O4 and NbFeB alloy, the porous oxide shell is silicon dioxide, the support material is a silicon dioxide microsphere, and the heat-conductive ceramic material is beryllium oxide; the mass percentage of the beryllium oxide in the carrier is 20%, the mass percentage of the Fe3O4 and NbFeB alloy in the carrier is 15%, and the thermal conductivity of the carrier is 82 W / (m·K).

[0131] The embodiment further provides a preparation method of the epoxidation catalyst, which comprises the following steps:

[0132] (1) Fe3O4 and NbFeB alloy spherical powders prepared by an aerosol method are added into 0.2 mol / L hydrochloric acid for ultrasonic treatment for 30 min, then separated by a magnet, and washed with deionized water until neutral to obtain pretreated magnetic powders; the pretreated magnetic powders are added into a reaction bottle, then ethanol, deionized water and ammonia water (25% in mass) are sequentially added into the reaction bottle, and the mixture is dispersed under ultrasonic condition for 1 h to obtain a dispersion liquid, the pH value of the dispersion liquid is 13, the mass ratio of the ethanol to the water is 1:4, and the mass percentage of the magnetic powders (Fe3O4 and NbFeB alloy) in the dispersion liquid is 1.5%; then tetraethyl orthosilicate (TEOS) is slowly added into the dispersion liquid for stirring reaction for 6 h, the mass ratio of the TEOS to the magnetic powders is 1:1, then permanent magnets are used for separation to obtain a reaction product; the reaction product is washed with deionized water until neutral, then dried at 120 ℃ for 3 h, and then calcined at 550 ℃ for 4 h to obtain porous oxide coated magnetic particles;

[0133] (2) the porous oxide coated magnetic particles, beryllium oxide powder and cellulose obtained in step (1) are mixed to obtain mixed powders, the mass percentage of the beryllium oxide in the mixed powders is 15%, and the mass percentage of the cellulose is 2%; the mixed powders are used for coating of the support material, i.e., the silicon dioxide microspheres, in a coating machine, the silicon dioxide microspheres with an average diameter of 0.5 mm are added into the coating machine, and the mixed powders and a silicon glue aqueous solution with a SiO2 mass concentration of 10% are sprayed into the coating machine for coating; when the diameter of the carrier spheres reaches 2-3 mm, the product is discharged, then dried at 110 ℃ for 3 h, and calcined at 600 ℃ for 3 h to obtain the carrier;

[0134] (3) loading the carrier obtained in step (2) into a reactor to form a carrier bed layer 2, the loading volume of the carrier bed layer 2 accounting for 80% of the volume of the reactor, and the structural diagram of the reactor and the carrier bed layer 2 is shown in Figure 1 the top view is shown in Figure 2 During the heating process, the power of the induction coil 1 is controlled by the medium frequency induction device, and the kettle body 8 and the baffle 3 are inductively heated. During the cooling process, the cooling medium passes through the reactor from the cooling medium passage 4 to the cooling circulating pump 7, and then is injected into the reactor through the cooling circulating pump 7 to cool down. The specific reaction process of step (3) is as follows:

[0135] The carrier bed layer 2 is first heated to 200°C, and a mixed gas of titanium tetrachloride vapor and nitrogen is introduced, wherein the volume percentage of titanium tetrachloride vapor is 10%, to obtain a first carrier bed layer;

[0136] The first carrier bed layer is second heated to 600°C, and nitrogen gas with a purity of 99.5% is introduced to obtain a second carrier bed layer;

[0137] The second carrier bed layer is first cooled to 300°C, and a mixed gas of water vapor and nitrogen is introduced, wherein the volume percentage of water vapor is 7%, to obtain a third carrier bed layer;

[0138] The third carrier bed layer is second cooled to 180°C, and a mixed gas of hexamethyldisilazane vapor and nitrogen is introduced, wherein the volume percentage of hexamethyldisilazane is 16%, to obtain an epoxidation catalyst;

[0139] After the above process is completed, the reactor is cooled to <60°C, and the reactor is opened. The catalyst product is transferred to the catalyst bin by a negative pressure suction system to obtain an epoxidation catalyst product;

[0140] During the first heating, the second heating, the first cooling and the second cooling processes, the temperature change rate of the carrier bed layer 2 is independently 4°C / min, the temperature difference between different parts of the carrier bed layer 2 during the heating process is ≤8°C, the heating time is 4h, and the temperature change rate of the baffle 3 and the kettle body 8 during the heating process is independently 4°C / min.

[0141] Example 2

[0142] The embodiment provides an epoxidation catalyst, which comprises a carrier and an epoxidation active catalytic layer supported on the carrier, the epoxidation active catalytic layer is a titanium layer, the carrier comprises a support material and a magnetic heat-conductive layer coated outside the support material, the magnetic heat-conductive layer contains a magnetic material and a heat-conductive ceramic material, the magnetic material comprises a magnetic particle inner core and a porous oxide shell coated outside the magnetic particle inner core, the magnetic particle inner core is an AlNiCo alloy and an AlFeCo alloy, the porous oxide shell is silicon dioxide, the support material is a silicon dioxide microsphere, and the heat-conductive ceramic material is silicon nitride; the mass percentage of the silicon nitride in the carrier is 25%, the mass percentage of the AlNiCo alloy and the AlFeCo alloy in the carrier is 20%, and the heat conductivity coefficient of the carrier is 105 W / (m·K).

[0143] The embodiment further provides a preparation method of the epoxidation catalyst, which comprises the following steps:

[0144] (1) spherical powders of the AlNiCo alloy and the AlFeCo alloy prepared by a gas atomization method are added into 0.2 moL / L hydrochloric acid for ultrasonic treatment for 30 min, then separated by a magnet, and washed with deionized water until neutral to obtain pretreated magnetic powders; the pretreated magnetic powders are added into a reaction bottle, then ethanol, deionized water and ammonia water (25% in mass) are sequentially added into the reaction bottle, and the mixture is dispersed under ultrasonic condition for 1.5 h to obtain a dispersion liquid, wherein the pH value of the dispersion liquid is 13, the mass ratio of the ethanol to the water is 1:5, and the mass percentage of the magnetic powders (AlNiCo alloy and AlFeCo alloy) in the dispersion liquid is 1%; then tetraethyl orthosilicate (TEOS) is slowly added into the dispersion liquid for stirring reaction for 5 h, the mass ratio of the TEOS to the magnetic powders is 1:0.9, then permanent magnets are used for separation to obtain a reaction product; the reaction product is washed with deionized water until neutral, then dried at 100℃ for 4 h, and then calcined at 500℃ for 5 h to obtain magnetic particles coated with a porous oxide;

[0145] (2) the magnetic particles coated with the porous oxide obtained in step (1), silicon nitride powder and cellulose are mixed to obtain mixed powders, wherein the mass percentage of the silicon nitride in the mixed powders is 20%, and the mass percentage of the cellulose in the mixed powders is 2%; the mixed powders are used to coat a support material, i.e., a silicon dioxide microsphere, in a coating machine, the silicon dioxide microspheres with an average diameter of 0.5 mm are added into the coating machine, a silicon glue aqueous solution with a SiO2 mass concentration of 8% is sprayed into the coating machine, and the mixed powders are added into the coating machine at the same time for coating; when the diameter of the carrier spheres reaches 3-4 mm, the material is discharged, then dried at 120℃ for 4 h, and calcined at 600℃ for 5 h to obtain a carrier.

[0146] (3) loading the carrier obtained in step (2) into a reactor to form a carrier bed layer, the loading volume of the carrier bed layer accounting for 80% of the volume of the reactor;

[0147] carrying out first temperature rising of the carrier bed layer to 150°C, keeping the temperature and passing in a mixed gas of titanium tetrachloride vapor and nitrogen, wherein the volume percentage of titanium tetrachloride vapor is 15%, to obtain a first carrier bed layer;

[0148] carrying out second temperature rising of the first carrier bed layer to 500°C, keeping the temperature and passing in nitrogen with a purity of 99.5%, to obtain a second carrier bed layer;

[0149] carrying out first temperature falling of the second carrier bed layer to 400°C, keeping the temperature and passing in a mixed gas of water vapor and nitrogen, wherein the volume percentage of water vapor is 5%, to obtain a third carrier bed layer;

[0150] carrying out second temperature falling of the third carrier bed layer to 300°C, keeping the temperature and passing in a mixed gas of trimethylchlorosilane vapor and nitrogen, wherein the volume percentage of trimethylchlorosilane is 10%, to obtain an epoxidation catalyst;

[0151] After the above process is completed, the reactor is cooled to <60°C, then the reactor is opened, and the catalyst product is transferred to a catalyst warehouse by a negative pressure suction system to obtain an epoxidation catalyst product;

[0152] In the processes of the first temperature rising, the second temperature rising, the first temperature falling and the second temperature falling, the temperature change rate of the carrier bed layer is independently 5°C / min, the temperature difference of different parts of the carrier bed layer is ≤8°C in the process of keeping the temperature, the temperature keeping time is 6h, and the temperature change rate of the partition plate and the kettle body is independently 5°C / min in the processes of the first temperature rising, the second temperature rising, the first temperature falling and the second temperature falling.

[0153] Example 3

[0154] The embodiment provides an epoxidation catalyst, which comprises a carrier and an epoxidation active catalytic layer loaded on the carrier, the epoxidation active catalytic layer is a titanium layer, the carrier comprises a support material and a magnetic heat-conductive layer coated outside the support material, the magnetic heat-conductive layer contains a magnetic material and a heat-conductive ceramic material, the magnetic material comprises a magnetic particle inner core and a porous oxide shell coated outside the magnetic particle inner core, the magnetic particle inner core is Fe3O4 and NbFeB alloy, the porous oxide shell is titanium dioxide, the support material is silica microspheres, the heat-conductive ceramic material is polycrystalline diamond ceramic (PCD), the mass percentage of PCD in the carrier is 30%, the mass percentage of Fe3O4 and NbFeB alloy in the carrier is 15%, and the thermal conductivity of the carrier is 135 W / (m·K).

[0155] The embodiment also provides a preparation method of the above-mentioned epoxidation catalyst, and the preparation method comprises the following steps:

[0156] (1) the spherical powder of Fe3O4 and NbFeB alloy prepared by the gas atomization method is added into 0.2 mol / L hydrochloric acid for ultrasonic treatment for 30 min, then separated by a magnet, and washed with deionized water until neutral to obtain a pretreated magnetic powder; the pretreated magnetic powder is added into a reaction bottle, then ethanol, deionized water and ammonia water (25% in mass) are sequentially added into the reaction bottle, and the mixture is dispersed under ultrasonic condition for 1.5 h to obtain a dispersion liquid, the pH value of the dispersion liquid is 12, the mass ratio of the ethanol to the water is 1:3, and the mass percentage of the magnetic powder (Fe3O4 and NbFeB alloy) in the dispersion liquid is 2%; then isopropyl titanate is slowly added into the dispersion liquid for stirring reaction for 7 h, the mass ratio of the isopropyl titanate to the magnetic powder is 1:0.8, then permanent magnet separation is adopted to obtain a reaction product; the reaction product is washed with deionized water until neutral, then dried at 140 ℃ for 2 h, and then calcined at 600 ℃ for 3 h to obtain a porous oxide coated magnetic particle;

[0157] (2) the porous oxide coated magnetic particle obtained in step (1), PCD powder and cellulose are mixed to obtain a mixed powder, the mass percentage of the PCD in the mixed powder is 30%, and the mass percentage of the cellulose in the mixed powder is 2%; the mixed powder is used to coat a support material of silica microspheres in a coating machine, the silica microspheres with an average diameter of 0.5 mm are added into the coating machine, a SiO2 aqueous solution with a mass concentration of 12% is sprayed into the coating machine at the same time, and the mixed powder is added into the coating machine to coat, when the diameter of the carrier spheres reaches 2-3 mm, the material is discharged, then dried at 120 ℃ for 5 h, and calcined at 550 ℃ for 5 h to obtain a carrier;

[0158] (3) the carrier obtained in step (2) is loaded into a reactor to form a carrier bed layer, and the loading volume of the carrier bed layer accounts for 80% of the volume of the reactor;

[0159] the carrier bed layer is subjected to first temperature rising to 300 ℃, and then the mixed gas of titanium tetrachloride vapor and nitrogen is introduced into the carrier bed layer, wherein the volume percentage of the titanium tetrachloride vapor is 8% to obtain a first carrier bed layer;

[0160] the first carrier bed layer is subjected to second temperature rising to 800 ℃, and then the nitrogen gas with a purity of 99.5% is introduced into the first carrier bed layer to obtain a second carrier bed layer;

[0161] the second carrier bed layer is subjected to first temperature lowering to 250 ℃, and then the mixed gas of water vapor and nitrogen is introduced into the second carrier bed layer, wherein the volume percentage of the water vapor is 10% to obtain a third carrier bed layer.

[0162] The third carrier bed is secondly cooled to 150℃, and a mixed gas of trimethylchlorosilane and nitrogen is introduced, wherein the volume percentage of trimethylchlorosilane is 25%, to obtain an epoxidation catalyst;

[0163] After the above process is completed, the reactor is cooled to <60℃, and the reactor is opened, and the catalyst product is transferred to a catalyst bin by a negative pressure suction system to obtain an epoxidation catalyst product.

[0164] In the processes of the first temperature rising, the second temperature rising, the first temperature falling and the second temperature falling, the temperature change rate of the carrier bed is independently 5℃ / min, the temperature difference of different parts of the carrier bed is ≤8℃ in the process of the temperature keeping, the time of the temperature keeping is 3h, and the temperature change rate of the baffle and the kettle body is independently 5℃ / min in the processes of the first temperature rising, the second temperature rising, the first temperature falling and the second temperature falling.

[0165] Example 4

[0166] The embodiment provides an epoxidation catalyst, and the difference between the epoxidation catalyst and the embodiment 1 is that the mass percentage of beryllium oxide in the carrier is 10%.

[0167] Example 5

[0168] The embodiment provides an epoxidation catalyst, and the difference between the epoxidation catalyst and the embodiment 1 is that the mass percentage of beryllium oxide in the carrier is 40%.

[0169] Example 6

[0170] The embodiment provides an epoxidation catalyst, and the difference between the epoxidation catalyst and the embodiment 1 is that the mass percentage of the core of the magnetic particle in the carrier is 10%.

[0171] Example 7

[0172] The embodiment provides an epoxidation catalyst, and the difference between the epoxidation catalyst and the embodiment 1 is that the mass percentage of the core of the magnetic particle in the carrier is 28%.

[0173] Example 8

[0174] The embodiment provides a preparation method of an epoxidation catalyst, and the difference between the preparation method and the embodiment 1 is that the temperature change rate of the carrier bed is independently 10℃ / min in the processes of the first temperature rising, the second temperature rising, the first temperature falling and the second temperature falling.

[0175] Example 9

[0176] The present example provides a preparation method of an epoxidation catalyst, which is different from example 1 only in that the temperature change rate of the carrier bed is 1℃ / min in the process of controlling the first temperature rise, the second temperature rise, the first temperature drop and the second temperature drop.

[0177] Comparative Example 1

[0178] The present comparative example provides an epoxidation catalyst, which is different from example 1 only in that the magnetic heat-conducting layer does not contain magnetic materials.

[0179] Comparative Example 2

[0180] The present comparative example provides an epoxidation catalyst, which is different from example 1 only in that the magnetic heat-conducting layer does not contain the heat-conducting ceramic material beryllium oxide.

[0181] Comparative Example 3

[0182] The present comparative example provides a preparation method of an epoxidation catalyst, which uses a commercially available silica carrier, and a conventional tubular reactor. The carrier is loaded into a tubular reactor with an inner diameter of 400mm, and the temperature of the heating furnace is set to 350℃ for 20h. After the temperature of the silica gel bed is balanced to 350℃, the process of preparing the epoxidation active catalyst layer is as follows: the carrier is sequentially subjected to active center vapor deposition, high temperature treatment, water treatment and silanization treatment in the tubular reactor to obtain an epoxidation catalyst, i.e.

[0183] First, the mixed gas of titanium tetrachloride vapor and nitrogen is introduced into the reactor to perform active center vapor deposition at 200℃ for 1h, and the amount of titanium tetrachloride vapor is 17kg. Then, high temperature treatment is performed at a temperature of 650℃ for 10h. Next, the mixed gas of nitrogen and water vapor is introduced into the reactor to perform water treatment at 300℃ for 1h, and the amount of water vapor is 20kg. Finally, the mixed gas of nitrogen and hexamethyldisilazane vapor is introduced into the reactor to perform silanization treatment at 180℃ for 1h, and the amount of hexamethyldisilazane vapor is 30kg. After the reaction is completed, the tubular reactor is cooled and disassembled to obtain an epoxidation catalyst.

[0184] Comparative Example 4

[0185] The comparative example provides a preparation method of an epoxidation catalyst, the preparation method uses a commercially available silica carrier, a conventional rotary reactor is used, the carrier is loaded into a rotary reactor with an inner diameter of 400 mm, the temperature of the heating furnace is set to 350℃, and the temperature is kept constant for 20 h. After the temperature of the silica gel bed is balanced to 350℃, the process of preparing an epoxidation active catalyst layer is carried out at 350℃ for 5 h. The process of preparing an epoxidation active catalyst layer is carried out by sequentially performing active center vapor deposition, high temperature treatment, water treatment and silanization treatment on the carrier in the rotary reactor, and the epoxidation catalyst is obtained, that is:

[0186] First, the mixed gas of titanium tetrachloride vapor and nitrogen is introduced into the reactor to perform active center vapor deposition at 200℃ and keep the reaction for 20 h, the amount of titanium tetrachloride vapor is 50 kg, then high temperature treatment is performed at a temperature of 650℃ and keeps the reaction for 20 h, then the mixed gas of nitrogen and water vapor is introduced into the reactor to perform water treatment at 300℃ and keep the reaction for 20 h, the amount of water vapor is 60 kg, finally, the mixed gas of nitrogen and hexamethyldisilazane vapor is introduced into the reactor to perform silanization treatment at 180℃ and keep the reaction for 20 h, the amount of hexamethyldisilazane vapor is 80 kg, after the reaction is completed, the rotary reactor is cooled and disassembled to obtain the epoxidation catalyst.

[0187] Comparative Example 5

[0188] The comparative example provides an epoxidation catalyst, which is a Ti-MCM-41 epoxidation catalyst prepared by a hydrothermal synthesis method, and a preparation method of the epoxidation catalyst is as follows:

[0189] (1) A 25wt% concentration of tetraethylammonium hydroxide (TEAOH) aqueous solution is prepared, 35.0g of tetraethyl orthosilicate (TEOS) is added dropwise into 29.7g of the tetraethylammonium hydroxide aqueous solution under stirring to form a mixed solution A;

[0190] (2) 1.2g of tetrabutyl titanate (TBOT) is added dropwise into 25.1g of triethanolamine (TEA) under stirring to form a mixed solution B;

[0191] (3) The mixed solution B is added dropwise into the mixed solution A under stirring, after stirring for 1h, 11.0g of deionized water (H2O) is added dropwise and stirred for 0.5h to form a homogeneous solution with a molar ratio of TEOS:TBOT:TEAOH:TEA:H2O of 1.0:0.02:0.3:1:11, the homogeneous solution is aged at 25℃ in the dark for 48h, and then air-dried at 100℃ for 24h to obtain dry white block-shaped particles;

[0192] (4) The dry white blocky particles were milled and then subjected to rotary heat treatment at 180°C for 4h in a homogeneous reactor, followed by calcination at 600°C for 10h in a muffle furnace at a temperature increase rate of 5°C / min to remove the template agent, thereby obtaining Ti-MCM-41 molecular sieve;

[0193] (5) The prepared Ti-MCM-41 molecular sieve was subjected to silanization treatment, i.e. the molecular sieve was loaded into a tubular reactor, a mixture of nitrogen and hexamethyldisilazane vapor was introduced into the reactor, and the silanization treatment was carried out at 180°C for 3h, after which the reaction product was added with silica sol for extrusion molding, thereby obtaining Ti-MCM-41 catalyst.

[0194] In the present comparative example, the catalyst was prepared by batch preparation, and the total time required for each step was >100h, and since the hydrolysis reaction process needs to be accurately controlled, it is difficult to scale up the preparation amount of a single batch of catalyst.

[0195] The preparation of 50kg of epoxidation catalyst was taken as a batch production, and the time length for the preparation of the epoxidation active catalytic layer in a single batch in Examples 1-9 and Comparative Examples 1-4 included the sum of the holding time and the temperature increase and decrease time, as shown in Table 2, wherein step (3) in Examples 1-9 and Comparative Examples 1-2 was the step for preparing the epoxidation active catalytic layer.

[0196] Catalytic activity test of the propylene epoxidation reaction for preparing propylene oxide:

[0197] The epoxidation catalysts in Examples 1-9 and Comparative Example 1-5 were subjected to activity test for the catalytic propylene epoxidation reaction for preparing propylene oxide, and the conditions were as follows: the epoxidation catalyst was loaded into a fixed bed reactor with an inner diameter of 30mm, the loading amount of the catalyst was controlled to be 20g, propylene was used as the raw material, and EBHP and CHP were used as the oxidants respectively to test the catalytic activity, in the process of using EBHP oxidant, the molar ratio of propane to EBHP was controlled to be 6:1, the feed mass space velocity was 3h -1 , the reaction pressure was 4.0MPa, and the reaction temperature was 60°C, and the conversion rate of EBHP and the selectivity of propylene oxide were tested, and the results are shown in Table 2; in the process of using CHP oxidant, the molar ratio of propane to CHP was controlled to be 8:1, the feed mass space velocity was 5h -1 , the reaction pressure was 4.0MPa, and the reaction temperature was 80°C, and the conversion rate of CHP and the selectivity of propylene oxide were tested, and the results are shown in Table 2.

[0198] The conversion rate of EBHP or CHP was determined by iodometric method, the potential titrator used in the iodometric method was produced by Metrohm Company, Switzerland, and the model was 916Ti-Touch, and the calculation formula was as follows:

[0199]

[0200] wherein, V is the volume of the consumed Na2S203 solution, C is the molar concentration of the used Na2S203 solution;

[0201]

[0202] The selectivity of propylene oxide is determined by a gas chromatograph. The gas chromatograph is GC-2010 Plus of Shimadzu. The mass concentration of propylene oxide in the reaction product after the catalytic activity test is calculated by the gas chromatograph. The method is internal standard method. DMF (dimethylformamide) is used as the solvent, and DT (dioxane) is used as the internal standard. The operating parameters of the gas chromatograph are shown in Table 1. The calculation formula is as follows:

[0203]

[0204] Table 1

[0205]

[0206]

[0207] Table 2

[0208]

[0209] The following points can be seen from Table 2:

[0210] (1) From the data of Examples 1-9, it can be seen that the epoxidation catalyst provided by the present application can make the conversion rate of EBHP reach more than 92.6% and the selectivity of propylene oxide reach more than 84.2% when EBHP is used as the oxidant for preparing propylene oxide by propylene epoxidation; the conversion rate of CHP can reach more than 93.6% and the selectivity of propylene oxide can reach more than 85.5% when CHP is used as the oxidant; under the more optimal conditions, the conversion rate of EBHP can reach more than 98.9% and the selectivity of propylene oxide can reach more than 93.6% when EBHP is used as the oxidant; the conversion rate of CHP can reach more than 99.3% and the selectivity of propylene oxide can reach more than 94.2% when CHP is used as the oxidant.

[0211] (2) Comprehensive comparison of the data of Example 1 and Examples 4-7 shows that the only difference between Examples 4-5 and Example 1 is that the mass percentage of beryllium oxide is not within the preferred range of the present application, and the only difference between Examples 6-7 and Example 1 is that the mass percentage of the magnetic particle core is not within the preferred range of the present application, and the conversion rate and selectivity of Example 1 are obviously higher than those of Examples 4-7, thus it can be seen that the preferred control of the mass percentages of the thermally conductive ceramic material and the magnetic particle core of the present application can further improve the activity and selectivity of the catalyst.

[0212] (3) Comprehensive comparison of the data of Example 1 and Examples 8-9 shows that the only difference between Examples 8-9 and Example 1 is that the temperature change rate of the carrier bed is not within the preferred range of the present application, and the conversion rate and selectivity of Example 1 are obviously higher than those of Examples 4-7, and the time length for preparing the epoxy active catalytic layer in a single batch in Example 1 is obviously lower than that in Example 9, thus it can be seen that the preferred control of the temperature change rate of the carrier bed of the present application can further improve the activity and selectivity of the catalyst, and at the same time improve the production efficiency.

[0213] (4) Comprehensive comparison of the data of Example 1 and Comparative Examples 1-2 shows that the only difference between Comparative Examples 1-2 and Example 1 is that they do not contain magnetic materials and thermally conductive ceramic materials, respectively, and the conversion rate and selectivity of Example 1 are obviously higher than those of Comparative Examples 1-2, and the time length for preparing the epoxy active catalytic layer in a single batch in Example 1 is obviously lower than that in Comparative Examples 1-2, thus it can be seen that the use of the magnetic and thermally conductive layer containing magnetic materials and thermally conductive ceramic materials of the present application can further improve the activity and selectivity of the catalyst, and at the same time improve the production efficiency.

[0214] (5) Comprehensive comparison of the data of Example 1 and Comparative Examples 3-5 shows that the only difference between Comparative Example 3 and Example 1 is that a silica carrier is used and a conventional tubular reactor is used to prepare the epoxy active catalytic layer; the only difference between Comparative Example 4 and Example 1 is that a silica carrier is used and a conventional rotary kiln reactor is used to prepare the epoxy active catalytic layer; the only difference between Comparative Example 5 and Example 1 is that a Ti-MCM-41 epoxidation catalyst prepared by a hydrothermal synthesis method is used, and the conversion rate and selectivity of Example 1 are obviously higher than those of Comparative Examples 3-5, and the time length for preparing the epoxy active catalytic layer in a single batch in Example 1 is obviously lower than that in Comparative Examples 3-4, while the preparation process of Comparative Example 5 is intermittent preparation and the total time required for each step is >100 h, which is also much higher than the preparation time of Example 1, thus it can be seen that the use of the carrier and preparation method provided by the present application can improve the activity and selectivity of the catalyst, and at the same time improve the production efficiency.

[0215] To sum up, the application provides the epoxidation catalyst, the carrier has the ferrimagnetism and the good thermal conductivity by controlling, the carrier can be heated by the electromagnetic induction, the temperature uniformity of the carrier bed layer is good in the preparation process, the temperature is loaded fast, the active center is uniformly loaded and the stability is good, the production efficiency of the catalyst deposition epoxy active catalytic layer process can be greatly improved, and the catalytic activity of the catalyst can be greatly improved.

[0216] The applicant declares that the above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto, and those skilled in the art should understand that any change or replacement within the technical scope disclosed by the application can be easily thought of by those skilled in the art in the technical field, and falls within the protection scope and disclosure range of the application.

Claims

1. An epoxidation catalyst characterized in that, The epoxidation catalyst comprises a carrier and an epoxidation active catalytic layer supported on the carrier; The epoxidation active catalytic layer comprises a transition metal layer; The carrier comprises a support material and a magnetic heat-conductive layer coated outside the support material; The magnetic heat-conductive layer contains a magnetic material and a heat-conductive ceramic material; The magnetic material comprises a magnetic particle inner core and a porous oxide shell coated outside the magnetic particle inner core; The magnetic particle inner core contains any one or a combination of at least two of Fe3O4, NbFeB alloy, AlNiCo alloy or AlFeCo alloy; The porous oxide shell contains any one or a combination of at least two of silicon dioxide, aluminum oxide or titanium dioxide; The heat-conductive ceramic material comprises any one or a combination of at least two of beryllium oxide, aluminum nitride, silicon carbide, silicon nitride or polycrystalline diamond ceramic; The transition metal layer comprises a titanium layer; The support material comprises silicon dioxide microspheres; The mass percentage of the heat-conductive ceramic material in the carrier is 15-30%; The mass percentage of the magnetic particle inner core in the carrier is 15-25%.

2. The epoxidation catalyst according to claim 1, characterized in that, The average diameter of the silicon dioxide microspheres is 0.4-0.6 mm.

3. The epoxidation catalyst of claim 1, wherein The shape of the carrier comprises any one of a spherical shape, an ellipsoidal shape, a cylindrical shape or a circular ring shape.

4. The epoxidation catalyst of claim 3, wherein The shape of the carrier is a spherical shape or a circular ring shape.

5. The epoxidation catalyst of claim 1, wherein The diameter of the carrier is 2-5 mm.

6. The epoxidation catalyst of claim 1, wherein The thermal conductivity of the carrier is 80-150 W / (m·K).

7. The epoxidation catalyst of claim 1, wherein The mass percentage of the carrier in the catalyst is 93-97%.

8. A process for the preparation of the epoxidation catalyst according to any one of claims 1 to 7, characterized in that The preparation method comprises the following steps: (1) mixing a magnetic powder, ethanol, water and ammonia water to obtain a dispersion liquid; then adding a porous oxide precursor dropwise into the dispersion liquid to react, and then separating to obtain a reaction product, and then sequentially washing, drying and calcining the reaction product to obtain a porous oxide coated magnetic particle; (2) mixing the porous oxide coated magnetic particle obtained in step (1), a heat-conductive ceramic material and a binder to obtain a mixed powder; coating the support material with the mixed powder, and then sequentially drying and calcining to obtain a carrier; (3) packing the carrier obtained in step (2) into a carrier bed layer, and then sequentially performing active center vapor deposition, high temperature treatment, water treatment and silanization treatment, and then cooling to obtain an epoxidation catalyst.

9. The production method according to claim 8, characterized by, The porous oxide precursor in step (1) comprises any one or a combination of at least two of silicate, aluminate or titanate.

10. The method of claim 8, wherein, The magnetic powder comprises any one or a combination of at least two of Fe3O4, NbFeB alloy, AlNiCo alloy or AlFeCo alloy.

11. The preparation method according to claim 8, characterized in that, The mass ratio of the porous oxide precursor to the magnetic powder is 1:(0.8-1).

12. The method of claim 8, wherein, The mass ratio of the ethanol to the water is 1:(3-5).

13. The preparation method according to claim 8, characterized in that, The mass percentage of the magnetic powder in the dispersion liquid is 1-2%.

14. The preparation method according to claim 8, characterized in that, The dispersion time is 1-1.5 h.

15. The method of claim 8, wherein the method further comprises, The dispersion is performed under ultrasonic condition.

16. The preparation method according to claim 8, characterized in that, The pH value of the dispersion liquid is 11-13.

17. The method of claim 8, wherein the method further comprises, The reaction time is 5-7 h.

18. The method of claim 8, wherein, The drying temperature in step (1) is 100-140℃.

19. The method of claim 8, wherein, The drying time of step (1) is 2-4h.

20. The method of claim 8, wherein, The calcination temperature of step (1) is 500-600℃.

21. The method of claim 8, wherein, The calcination time of step (1) is 3-5h.

22. The preparation method according to claim 8, characterized in that, The mass percentage of the heat-conducting ceramic material in the mixed powder of step (2) is 15-30%.

23. The preparation method according to claim 8, characterized in that, The mass percentage of the binder in the mixed powder is 2-5%.

24. The method of claim 8, wherein, The coating is performed in a coating machine.

25. The method of claim 8, wherein the method further comprises, An additive is added during the coating.

26. The method of claim 25, wherein, The additive comprises a silica aqueous solution.

27. The method of claim 26, wherein, The mass percentage of SiO2 in the silica aqueous solution is 8-12%.

28. The method of claim 8, wherein the method further comprises, The drying temperature of step (2) is 100-120℃.

29. The method of claim 8, wherein the method further comprises, The drying time of step (2) is 3-5h.

30. The method of claim 8, wherein, The calcination temperature of step (2) is 500-700℃.

31. The method of claim 8, wherein the method further comprises, The calcination time of step (2) is 3-5h.

32. The method of claim 8, wherein the method is carried out at a temperature of about 20°C to about 30°C. The process of active center vapor deposition of step (3) comprises: first heating the carrier bed layer to a first reaction temperature, keeping the temperature and introducing a first reaction gas to obtain a first carrier bed layer; The process of high-temperature treatment comprises: second heating the first carrier bed layer to a second reaction temperature, keeping the temperature and introducing a second reaction gas to obtain a second carrier bed layer; The process of water treatment comprises: first cooling the second carrier bed layer to a third reaction temperature, keeping the temperature and introducing a third reaction gas to obtain a third carrier bed layer; The process of silanization treatment comprises: second cooling the third carrier bed layer to a fourth reaction temperature, keeping the temperature and introducing a fourth reaction gas to obtain an epoxidation catalyst.

33. The method of claim 32, wherein the method is performed in a single step. The first reaction gas comprises a mixture of titanium compound vapor and nitrogen.

34. The method of claim 33, wherein, The volume percentage of titanium compound vapor in the first reaction gas is 5-15%.

35. The preparation method according to claim 33, characterized in that, The titanium compound vapor comprises any one or a combination of at least two of titanium tetrafluoride, titanium tetrachloride, titanium tetrabromide, tetraethyl titanate, tetrapropyl titanate or tetrabutyl titanate.

36. The method of claim 32, wherein, The first reaction temperature is 150-300℃.

37. The method of claim 32, wherein the method is carried out at a temperature of about 20°C to about 30°C. The second reaction gas comprises nitrogen.

38. The method of claim 32, wherein, The purity of the second reaction gas is ≥99.5%.

39. The method of claim 32, wherein, The second reaction temperature is 500-800℃.

40. The method of claim 32, wherein, The third reaction gas comprises a mixture of water vapor and nitrogen.

41. The method of claim 40, wherein, The volume percentage of water vapor in the third reaction gas is 5-10%.

42. The method of claim 32, wherein, The third reaction temperature is 250-400℃.

43. The method of claim 32, wherein the method is carried out at a temperature of about 20°C to about 30°C. The fourth reaction gas comprises a mixture of organosilane vapor and nitrogen.

44. The method of claim 43, wherein the method further comprises, The organosilane vapor comprises any one or a combination of at least two of hexamethyldisilazane, hexamethylchlorosilazane, heptamethylchlorosilazane, trimethylchlorosilane, dimethylchlorosilane, tetramethyldisilazane, dimethyldiethoxysilane, trimethylmethoxysilane, dimethyldimethoxysilane or trimethylethoxysilane.

45. The preparation method according to claim 43, characterized in that, The volume percentage of organosilane vapor in the fourth reaction gas is 10-25%.

46. The method of claim 32, wherein, The fourth reaction temperature is 150-300℃.

47. The method of claim 32, wherein the method is carried out at a temperature of about 20°C to about 30°C. In the processes of first heating, second heating, first cooling and second cooling, the temperature change rate of the carrier bed layer is independently 2-5℃ / min.

48. The method of claim 32, wherein, The temperature difference between different parts of the carrier bed layer during the keeping temperature is ≤8℃.

49. The method of claim 48, wherein, The temperature difference between different parts of the carrier bed during the holding process is less than or equal to 5°C.

50. The method of claim 32, wherein, The holding time is 2-6 hours.

51. The method of claim 8, wherein, The carrier bed is filled in the reactor.

52. The method of claim 51, wherein, The filling volume of the carrier bed accounts for more than or equal to 80% of the volume of the reactor.

53. The method of claim 51, wherein, The reactor comprises a kettle body; the kettle body is cylindrical; at least one set of baffles is arranged in the kettle body in a direction perpendicular to the axial direction of the kettle body; the baffles comprise at least two fins at the same height; at least two cooling medium channels are arranged in the kettle body in a direction parallel to the axial direction of the kettle body; the cooling medium channels pass through the inside of the fins; an induction coil is arranged on the outer side wall of the kettle body.

54. The method of claim 53, wherein, The top of the kettle body is provided with a tail gas pipeline.

55. The preparation method according to claim 53, characterized in that, The bottom of the kettle body is provided with a gas phase inlet pipeline.

56. The preparation method according to claim 53, characterized in that, The inlet of the cooling medium channel is connected with the outlet of the cooling circulating pump.

57. The method of claim 53, wherein the method further comprises, The outlet of the cooling medium channel is connected with the inlet of the cooling circulating pump.

58. The method of claim 53, wherein, The baffles and the kettle body are both ferromagnetic metal materials.

59. The method of claim 32, wherein, During the first temperature rising, the second temperature rising, the first temperature falling and the second temperature falling, the temperature change rate of the baffles and the kettle body is independently 2-5°C / min.

60. The method of claim 59, wherein, During the first temperature rising, the second temperature rising, the first temperature falling and the second temperature falling, the temperature change rate of the baffles and the kettle body is independently 3-5°C / min.

61. Use of an epoxidation catalyst according to any one of claims 1 to 7, characterized in that The epoxidation catalyst is used for liquid phase epoxidation reaction of olefins and oxidants.

62. The use according to claim 61, characterized in that The olefins include any one or a combination of at least two of C3-C 10 linear olefins, C3-C 10 isomeric olefins, C6-C 16 cyclic olefins or C6-C 16 aromatic olefins.

63. The use of claim 61, wherein, The oxidant comprises organic peroxide.

64. The use of claim 63, wherein, The organic peroxide comprises any one or a combination of at least two of tert-butyl hydroperoxide, ethylbenzene hydroperoxide or cumyl hydroperoxide.

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