A process for the preparation of epoxy stilbene

Abstract

The present application relates to a method for preparing epoxy styrene, which comprises: (1) contacting ethylbenzene, a first oxidizing agent containing oxygen and nanocarbon material to carry out an oxidative dehydrogenation reaction, carrying out gas-liquid separation on the obtained reaction mixture to obtain a gas phase product and a liquid phase product, and then separating the liquid phase product to obtain an oil phase product and an aqueous phase product; (2) mixing the oil phase product with a second oxidizing agent containing oxygen and hydrogen in the presence of an optional solvent, and then contacting with a bifunctional titanium-silicon catalyst to carry out a direct epoxidation reaction. The method of the present application has a high selectivity of epoxy styrene.

Description

TECHNICAL FIELD

[0001] The application relates to a method for preparing epoxy styrene. BACKGROUND

[0002] Epoxides such as epoxy styrene are chemically very active and have a wide range of uses, mainly for producing polyether, non-polyether polyol, surfactant, etc., and are widely used in chemical industry, light industry, medicine, food, textile and other industries, and have a profound influence on the development of chemical industry and national economy. However, there are problems such as low conversion rate and poor selectivity in the prior art, and improvement is urgently needed. SUMMARY

[0003] The purpose of the present application is to provide a method for preparing epoxy styrene, which has high selectivity of epoxy styrene.

[0004] In order to achieve the above-mentioned purpose, the present application provides a method for preparing epoxy styrene, which comprises:

[0005] (1) contacting ethylbenzene, a first oxidizing agent containing oxygen and a nano-carbon material to perform an oxidative dehydrogenation reaction, performing gas-liquid separation on the obtained reaction mixture to obtain a gas phase product and a liquid phase product, and then separating the liquid phase product to obtain an oil phase product and an aqueous phase product;

[0006] (2) mixing the oil phase product with a second oxidizing agent containing oxygen and hydrogen in the presence of an optional solvent, and then contacting with a bifunctional titanium-silicon catalyst to perform a direct epoxidation reaction.

[0007] Optionally, in step (1), the conditions of the oxidative dehydrogenation reaction include: temperature is 300-600 DEG C, pressure is 0.1-5 MPa, time is 1-10 hours, and the molar ratio of ethylbenzene to oxygen in the first oxidizing agent containing oxygen is 1:(0.2-5).

[0008] Optionally, the nano-carbon material is prepared by a method comprising the following steps: calcining a biomass carbon material at 800-1300 DEG C for 2-10 hours under an ammonia atmosphere to obtain the nano-carbon material.

[0009] The carbon content of the nano-carbon material is 80-99.9 wt%, the nitrogen content is 0.1-10 wt%, and the balance is oxygen, based on the total weight of the nano-carbon material; preferably, the carbon content of the nano-carbon material is 90-98 wt%, and the nitrogen content is 0.2-5 wt%.

[0010] The ammonia atmosphere contains ammonia and nitrogen, and the content of ammonia is 0.1-10 vol%; the biomass carbon material is selected from one or more of cellulose, hemicellulose, lignin, sucrose and starch.

[0011] Optionally, in step (1), the oil phase product contains styrene and unreacted ethylbenzene, the content of styrene is 10-90% by weight, preferably 15-75% by weight, and the balance is ethylbenzene, based on the total weight of the oil phase product.

[0012] Optionally, in step (2), the conditions of the direct epoxidation reaction include: temperature is 10-70℃, pressure is 0.1-5MPa, and time is 1-18 hours.

[0013] Optionally, in step (2), the molar ratio of the oil phase product, the second oxidant containing oxygen and hydrogen is 1:(0.1-10):(0.1-10), preferably 1:(0.2-5):(0.2-5), the oil phase product is calculated based on styrene, and the oxidant containing oxygen is calculated based on oxygen.

[0014] Optionally, in step (2), the weight ratio of the oil phase product to the bifunctional titanium-silicon catalyst is 100:(1-20), preferably 100:(2-15).

[0015] The weight ratio of the amount of the solvent to the bifunctional titanium-silicon catalyst is (0-1000):1, preferably (20-500):1.

[0016] Optionally, the bifunctional titanium-silicon catalyst contains noble metal and titanium-silicon molecular sieve;

[0017] The content of the noble metal is 0.05-10% by weight, and the content of the titanium-silicon molecular sieve is 90-99.95% by weight, based on the total weight of the bifunctional titanium-silicon catalyst.

[0018] The noble metal includes one and several of palladium, palladium, osmium, iridium, platinum, gold, ruthenium, rhodium and silver.

[0019] The silicon-titanium molar ratio of the titanium-silicon molecular sieve is 15-100.

[0020] Optionally, the gas-liquid separation of the obtained reaction mixture includes: exchanging heat between the oxidation dehydrogenation reaction mixture in step (1) and the reaction product obtained from the direct epoxidation reaction in step (2).

[0021] Optionally, the method is a continuous operation, in step (1), the volume space velocity of the ethylbenzene is 0.1-1000h -1 , the total volume space velocity of the epoxidation reaction is 0.1-500h -1 , preferably 1-200h -1 .

[0022] By the technical scheme, the method of the present application makes styrene obtained after the oxidation dehydrogenation reaction of ethylbenzene mixed with an oxidant containing oxygen, and a peroxide species is formed in the process of contacting with a bifunctional titanium-silicon catalyst, and then the styrene is epoxidized to prepare epoxyphenylmethane, and the selectivity of the epoxyphenylmethane is high.

[0023] Other features and advantages of the present application will be described in detail in the following specific embodiments. DETAILED DESCRIPTION

[0024] The specific embodiments of the present application are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0025] The first aspect of the present application provides a method for preparing epoxyphenylmethane, which comprises:

[0026] (1) performing an oxidation dehydrogenation reaction on ethylbenzene, a first oxidant containing oxygen and nano-carbon material in contact, performing gas-liquid separation on the obtained reaction mixture to obtain a gas phase product and a liquid phase product, and then separating the liquid phase product to obtain an oil phase product and an aqueous phase product;

[0027] (2) mixing the oil phase product with a second oxidant containing oxygen and hydrogen in the presence of an optional solvent, and then contacting with a bifunctional titanium-silicon catalyst to perform a direct epoxidation reaction.

[0028] The method of the present application has a simple process, does not need to purify the intermediate styrene product, and has a higher selectivity of epoxyphenylmethane.

[0029] According to the present application, the method for separating the liquid phase product in step (2) is well known to those skilled in the art, for example, the liquid phase product can be separated by sedimentation to obtain an oil phase product and an aqueous phase product.

[0030] According to the present application, the oxidation dehydrogenation reaction is well known to those skilled in the art. In one specific embodiment of the present application, in step (1), the conditions of the oxidation dehydrogenation reaction include: temperature of 300-600℃, pressure of 0.1-5MPa, time of 1-10 hours, and molar ratio of oxygen in ethylbenzene to the first oxidant containing oxygen of 1:(0.2-5); preferably, temperature of 350-550℃, pressure of 0.2-2.5MPa, time of 2-5 hours, and molar ratio of oxygen in ethylbenzene to the first oxidant containing oxygen of 1:(0.2-2).

[0031] According to the present application, the first oxidant containing oxygen contains oxygen and optionally one or more of nitrogen, carbon dioxide and other inert gases, and the second oxidant containing oxygen contains oxygen and optionally one or more of nitrogen, carbon dioxide and other inert gases, preferably, the first oxidant is oxygen and the second oxidant is oxygen.

[0032] According to the present application, the oil phase product contains styrene and unreacted ethylbenzene, the content of styrene can be 10-90 wt%, preferably 15-75 wt%, based on the total weight of the oil phase product, and the balance is ethylbenzene; the water phase product mainly contains water produced by the oxidative dehydrogenation reaction, and the water can be 90-100 wt%, and the balance is the mixed ethylbenzene and styrene.

[0033] According to the present application, the source of the nanocarbon material is not specifically limited, and can be obtained by commercial purchase or self-preparation. In one specific embodiment of the present application, the nanocarbon material is an ammonia-nitrogen modified biomass carbon particle, and the nanocarbon material is prepared by a method comprising the following steps: calcining a biomass carbon material at 800-1300°C for 2-10h under an ammonia atmosphere to obtain the nanocarbon material. The carbon content of the nanocarbon material is 80-99.9 wt%, the nitrogen content is 0.1-10 wt%, and the balance is oxygen, based on the total weight of the nanocarbon material; preferably, the carbon content of the nanocarbon material is 90-98 wt%, the nitrogen content is 0.2-5 wt%, and the balance is oxygen. The biomass carbon material is well known to those skilled in the art, and preferably the biomass carbon material is selected from one or more of cellulose, hemicellulose, lignin, sucrose and starch.

[0034] According to the present application, in order to prepare a nanocarbon material with good physical and chemical properties, the ammonia atmosphere contains nitrogen as a balancing gas, and the content of ammonia can vary within a wide range. In one specific embodiment of the present application, the content of ammonia is 0.1-10 vol%, preferably 0.5-2 vol%.

[0035] In one specific embodiment of the present application, in step (1), the amount of the nanocarbon material is 0.01-10g, preferably 0.1-5g, relative to 100mL of ethylbenzene.

[0036] In one specific embodiment of the present application, in step (2), the conditions of the direct epoxidation reaction include a temperature of 10-70°C, a pressure of 0.1-5MPa, and a time of 1-18 hours; preferably, the temperature is 20-60°C, the pressure is 0.5-3MPa, and the time is 3-8 hours.

[0037] In one embodiment of the present application, in step (2), the molar ratio of the oil phase product, the second oxidant containing oxygen and hydrogen is 1:(0.1-10):(0.1-10), preferably 1:(0.2-5):(0.2-5), the oil phase product is calculated based on styrene, the second oxidant containing oxygen is calculated based on oxygen; the weight ratio of the oil phase product to the bifunctional titanium silicalite catalyst is 100:(1-20), preferably 100:(2-15); the weight ratio of the solvent to the bifunctional titanium silicalite catalyst is (0-1000):1, preferably (20-500):1. The solvent can be selected from one or more of water, alcohol, ketone and nitrile; preferably, the alcohol is selected from one or more of methanol, ethanol, n-propanol, isopropanol, t-butanol and isobutanol; the ketone can be acetone and / or butanone; the nitrile can be acetonitrile. Preferably, the solvent is acetone.

[0038] According to the present application, the second oxidant containing oxygen can include, but is not limited to, air. Using air as the oxygen source can greatly reduce the production cost.

[0039] In one embodiment of the present application, the bifunctional titanium silicalite catalyst contains noble metal and titanium silicalite. The present application does not specifically limit the form of the noble metal, which, in one embodiment, is supported on the surface and internal pores of the titanium silicalite. The titanium silicalite is well known to those skilled in the art, for example, can be one or more of molecular sieves with MFI structure, MOR structure, BEA structure, etc. The content of the noble metal is 0.05-10% by weight, preferably 0.1-4% by weight, based on the total weight of the bifunctional titanium silicalite catalyst; the content of the titanium silicalite is 90-99.95% by weight, preferably 92-98% by weight; the noble metal includes one or more of palladium, osmium, iridium, platinum, gold, ruthenium, rhodium and silver, preferably one or more of palladium, platinum, gold and silver; the silicon-titanium molar ratio of the titanium silicalite can vary in a wide range, preferably 15-100, more preferably 20-50. The bifunctional titanium silicalite catalyst used in the method of the present application can directly in situ react the styrene obtained by oxidizing dehydrogenating ethylbenzene with the second oxidant containing oxygen and hydrogen to obtain the target product, epoxyphenylcyclohexane.

[0040] In one embodiment of the present application, the gas-liquid separation of the obtained reaction mixture includes: exchanging heat between the oxidizing dehydrogenation reaction mixture in step (1) and the reaction product obtained by the direct epoxidation reaction in step (2).

[0041] In one embodiment of the present application, the method is a continuous operation, in step (1), the volume space velocity of the ethylbenzene is 0.1-1000 h -1The total volume hourly space velocity of the epoxidation reaction can vary within a wide range, for example, it can be from 0.1 to 500 h -1 , preferably from 1 to 200 h -1 .

[0042] The application will be further illustrated by the following examples, but the application is not limited in any way by the examples.

[0043] The reagents used in the examples and comparative examples are commercially available chemical reagents of chemical purity unless otherwise specified.

[0044] The nano-carbon material is biomass carbon particles modified by ammonia nitrogen. The specific preparation method is as follows: cellulose is calcined at 1100°C for 6h under an ammonia gas atmosphere of 2% by volume, and the balance gas is nitrogen. The content of carbon in the nano-carbon material is 93% by weight, the content of nitrogen is 2.1% by weight, and the balance is oxygen.

[0045] The titanium silicalite (TS-1) is a (TS-1) molecular sieve sample prepared according to the method described in the prior art Zeolites, 1992, Vol. 12, pages 943-950. The titanium silicalite (TS-1) has a silicon-titanium molar ratio of 27.

[0046] The preparation process of the bifunctional titanium silicalite catalyst is as follows: 10g of titanium silicalite is added to 20mL of an aqueous PdCl2 solution with a Pd concentration of 0.01g / mL, stirred at a temperature of 40°C for 24 hours, sealed appropriately during the stirring, and then naturally dried at room temperature for 48 hours to obtain the bifunctional titanium silicalite (2wt% Pd / TS) catalyst (which needs to be reduced and activated at a temperature of 300°C for 3 hours in a nitrogen-hydrogen mixed gas atmosphere before the reaction is carried out).

[0047] Example 1

[0048] (1) At a normal pressure of 400°C, a molar ratio of ethylbenzene to the first oxidant oxygen of 1:2, and a volume hourly space velocity of ethylbenzene of 25 h -1 , the ethylbenzene and the first oxidant oxygen are first subjected to an oxidative dehydrogenation reaction in a bed layer with the nano-carbon material as a catalyst for 6h, the obtained reaction mixture is heat-exchanged with the direct epoxidation reaction product, and then subjected to gas-liquid separation to obtain a gas phase product and a liquid phase product, and then the liquid phase product is settled to obtain an oil phase product and an aqueous phase product; the content of styrene in the oil phase product is 21% by weight, and the balance is ethylbenzene (the same below);

[0049] (2) The oil phase product is mixed with hydrogen, the second oxidant oxygen, and acetone, and then subjected to a reaction at a temperature of 40°C, a pressure of 2.5MPa, and a total volume hourly space velocity of 10 h -1The direct epoxidation reaction product was obtained by contacting the oil phase product with the bifunctional titanium silical catalyst at 300℃ for 3h. The molar ratio of the oil phase product, hydrogen and oxygen was 1:2:1, the weight ratio of the oil phase product to the bifunctional titanium silical catalyst was 1:0.01, and the weight ratio of the methanol to the bifunctional titanium silical catalyst was 20.

[0050] Example 2

[0051] (1) The oxidation dehydrogenation reaction was carried out by passing ethylbenzene and the first oxidant oxygen through a bed of the nanocarbon material catalyst at 500℃ under normal pressure for 4h. The molar ratio of ethylbenzene to the first oxidant oxygen was 1:0.5, and the volume space velocity of ethylbenzene was 100h -1 The oxidation dehydrogenation reaction was carried out by passing ethylbenzene and the first oxidant oxygen through a bed of the nanocarbon material catalyst at 500℃ under normal pressure for 4h. The molar ratio of ethylbenzene to the first oxidant oxygen was 1:0.5, and the volume space velocity of ethylbenzene was 100h

[0052] (2) The oil phase product was mixed with hydrogen, the second oxidant oxygen and methanol, and then the mixture was subjected to the direct epoxidation reaction at a temperature of 40℃ and a pressure of 2.5MPa under a total volume space velocity of 2h -1 The direct epoxidation reaction product was obtained by contacting the oil phase product with the bifunctional titanium silical catalyst at 300℃ for 3h. The molar ratio of the oil phase product, hydrogen and oxygen was 1:2:1, the weight ratio of the oil phase product to the bifunctional titanium silical catalyst was 1:0.01, and the weight ratio of the methanol to the bifunctional titanium silical catalyst was 20.

[0053] Example 3

[0054] (1) The oxidation dehydrogenation reaction was carried out by passing ethylbenzene and the first oxidant air (calculated by the oxygen therein) through a bed of the nanocarbon material catalyst at 300℃ under normal pressure for 10h. The molar ratio of ethylbenzene to the first oxidant air (calculated by the oxygen therein) was 1:5, and the volume space velocity of ethylbenzene was 12h -1 The oxidation dehydrogenation reaction was carried out by passing ethylbenzene and the first oxidant air (calculated by the oxygen therein) through a bed of the nanocarbon material catalyst at 300℃ under normal pressure for 10h. The molar ratio of ethylbenzene to the first oxidant air (calculated by the oxygen therein) was 1:5, and the volume space velocity of ethylbenzene was 12h

[0055] (2) The oil phase product was mixed with hydrogen, the second oxidant air and tert-butyl alcohol, and then the mixture was subjected to the direct epoxidation reaction at a temperature of 50℃ and a pressure of 1.5MPa under a total volume space velocity of 100h -1The direct epoxidation reaction product was obtained by contacting the oil phase product with the bifunctional titanium silical catalyst for 2 h. The molar ratio of the oil phase product, hydrogen, and the second oxidant air (calculated based on the oxygen therein) was 1:1:2, the weight ratio of the oil phase product to the bifunctional titanium silical catalyst was 1:0.1, and the weight ratio of the t-butyl alcohol to the bifunctional titanium silical catalyst was 50.

[0056] Example 4

[0057] The epoxystyrene was prepared by the same method as in Example 1, except that the nano-carbon material used in step (1) was prepared by the following method:

[0058] The cellulose was calcined at 800℃ for 12 h under an atmosphere of 0.1% ammonia by volume, with nitrogen as the balance gas. The nano-carbon material contained 85% carbon by weight and 0.1% nitrogen by weight, with the balance being oxygen.

[0059] Example 5

[0060] The epoxystyrene was prepared by the same method as in Example 1, except that the conditions for the oxidative dehydrogenation reaction in step (1) included a temperature of 300℃, a pressure of 0.1 MPa, a time of 6 hours, and a molar ratio of ethylbenzene to oxygen of 1:3.

[0061] Example 6

[0062] The epoxystyrene was prepared by the same method as in Example 1, except that the molar ratio of the oil phase product, the second oxidant oxygen, and hydrogen in step (2) was 1:5.5:6.

[0063] Comparative Example 1

[0064] The epoxystyrene was prepared by the same method as in Example 1, except that no nano-carbon material was used in step (1).

[0065] Comparative Example 2

[0066] The epoxystyrene was prepared by the same method as in Example 1, except that no bifunctional titanium silical catalyst was used in step (2).

[0067] Comparative Example 3

[0068] The epoxystyrene was prepared by the same method as in Example 1, except that no nano-carbon material was used in step (1) and no bifunctional titanium silical catalyst was used in step (2).

[0069] Comparative Example 4

[0070] The same method as in Example 1 was used to prepare the epoxystyrene, except that in step (2) titanium silicalite (TS-1) was used instead of the bifunctional titanium silicalite catalyst.

[0071] Table 1

[0072]

[0073]

[0074] As can be seen from Table 1, the method provided by the present application can be used to prepare epoxystyrene from ethylbenzene, and has a high ethylbenzene conversion rate and epoxystyrene selectivity.

[0075] The above describes preferred embodiments of the present application in detail, but the present application is not limited to the specific details in the above-described embodiments, and within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, and these simple modifications all belong to the protection scope of the present application.

[0076] In addition, it should be noted that each specific technical feature described in the above-described specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present application will not describe various possible combinations again.

[0077] In addition, various different embodiments of the present application can also be combined in any manner, as long as it does not deviate from the idea of the present application, and it should also be considered as disclosed by the present application.

Claims

1. A method for preparing epoxide phenylene oxide, the method comprising: (1) ethylbenzene, oxygen-containing first oxidant and nano carbon material are brought into contact to carry out oxidative dehydrogenation reaction, and the resulting reaction mixture is separated into gas and liquid phase products to obtain gas phase products and liquid phase products. The liquid phase products are then separated to obtain oil phase products and aqueous phase products. The nano-carbon material is prepared by a method comprising the following steps: calcining biomass carbon material at 800-1300°C for 2-10 hours under an ammonia atmosphere to obtain the nano-carbon material; based on the total weight of the nano-carbon material, the carbon content of the nano-carbon material is 90-98% by weight, and the nitrogen content is 0.2-5% by weight; the ammonia atmosphere contains ammonia and nitrogen, and the ammonia content is 0.1-10% by volume; the conditions for the oxidative dehydrogenation reaction include: a temperature of 300-600°C, a pressure of 0.1-5 MPa, a time of 1-10 hours, and a molar ratio of ethylbenzene to oxygen in the oxygen-containing first oxidant of 1:(0.2-5). (2) In the presence of an optional solvent, the oil phase product is mixed with an oxygen-containing second oxidant and hydrogen, and then contacted with a bifunctional titanium-silicon catalyst to carry out a direct epoxidation reaction. The bifunctional titanium-silicon catalyst contains noble metals and titanium-silicon molecular sieves; based on the total weight of the bifunctional titanium-silicon catalyst, the content of the noble metals is 0.1-4% by weight, and the content of the titanium-silicon molecular sieves is 82-98% by weight; the silicon-titanium molar ratio of the titanium-silicon molecular sieves is 15-100; the conditions for the direct epoxidation reaction include: a temperature of 10-70℃, a pressure of 0.1-5MPa, and a time of 1-18 hours.

2. The method according to claim 1, wherein, The biomass carbon material is selected from one or more of cellulose, hemicellulose, lignin, sucrose, and starch.

3. The method according to claim 1 or 2, wherein, In step (1), the oil phase product contains styrene and unreacted ethylbenzene. Based on the total weight of the oil phase product, the styrene content is 10-90% by weight, with the remainder being ethylbenzene.

4. The method according to claim 3, wherein, In step (1), based on the total weight of the oil phase product, the styrene content is 15-75% by weight, with the remainder being ethylbenzene.

5. The method according to claim 1, wherein, In step (2), the molar ratio of the oil phase product, the oxygen-containing second oxidant, and the amount of hydrogen is 1:(0.1-10):(0.1-10), the oil phase product is based on styrene, and the oxygen-containing oxidant is based on oxygen.

6. The method according to claim 5, wherein, In step (2), the molar ratio of the oil phase product, the oxygen-containing second oxidant, and the amount of hydrogen is 1:(0.2-5):(0.2-5), the oil phase product is based on styrene, and the oxygen-containing oxidant is based on oxygen.

7. The method according to claim 1, wherein, In step (2), the weight ratio of the oil phase product to the bifunctional titanium-silicon catalyst is 100:(1-20). The weight ratio of the solvent to the bifunctional titanium-silicon catalyst is (0-1000):

1.

8. The method according to claim 7, wherein, In step (2), the weight ratio of the oil phase product to the bifunctional titanium-silicon catalyst is 100:(2-15). The weight ratio of the solvent to the bifunctional titanium-silicon catalyst is (20-500):

1.

9. The method according to claim 1, wherein, The precious metals include one or more of palladium, palladium, osmium, iridium, platinum, gold, ruthenium, rhodium, and silver.

10. The method according to claim 1, wherein, The gas-liquid separation of the obtained reaction mixture includes: exchanging heat between the reaction mixture in step (1) and the reaction product obtained from the direct epoxidation reaction in step (2).

11. The method according to claim 1, wherein, This method is a continuous operation. In step (1), the volume hourly space velocity (VHSV) of the ethylbenzene is 0.1-1000 h⁻¹. -1 The total volume hourly space velocity (VHSV) of the epoxidation reaction is 0.1-500 h⁻¹. -1 .

12. The method according to claim 11, wherein, The total volume hourly space velocity of the epoxidation reaction is 1-200 h⁻¹. -1 .

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