CN106431861B - The method and apparatus of styrene oxidation coproduction benzaldehyde, styrene oxide and Styrene carbonate - Google Patents

Abstract

The invention discloses a method and a device for oxidizing styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate. The method for the oxidation of styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate comprises the following steps: A) mixing styrene, a solvent and a catalyst, and adding an oxidizing agent to carry out the oxidation reaction to obtain a reaction feed liquid and Mixed gas, the reaction feed liquid contains benzaldehyde and styrene oxide, and the mixed gas contains formaldehyde; B) Separation of the reaction feed liquid to obtain benzaldehyde and styrene oxide; C) Catalytic oxidation treatment of the mixed gas to convert formaldehyde being carbon dioxide and water; and D) reacting a mixed gas containing carbon dioxide with a portion of styrene oxide to produce styrene cyclic carbonate. The method for oxidizing styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate according to the embodiment of the present invention has the advantages of high economic benefit, environmental protection and the like.

Description

Styrene oxidation co-production of benzaldehyde, styrene oxide and styrene cyclic carbonate method and device

technical field

The invention relates to the field of chemistry, in particular to a method and a device for oxidizing styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate.

Background technique

The main products of oxygen oxidation of styrene are styrene oxide and benzaldehyde, both of which are widely used as intermediates in the synthesis of fine chemicals. Among them, due to the presence of active epoxy groups, styrene oxide can react with various substances to form high value-added compounds, which are used in the fields of fragrance production and drug preparation, such as the preparation of fragrance β-phenylethanol and simidazole; benzaldehyde It can be used to synthesize food additives such as L-phenylalanine. In recent years, with the sharp increase in demand for such fine chemical products, styrene oxide and benzaldehyde have attracted much attention no matter in terms of industrial production or organic synthesis. At present, the method of industrially synthesizing styrene oxide mainly contains the chlorohydrin method. Although the method is simple in process and high in yield, it has serious environmental pollution, many by-products, difficult operation for separation, and high material consumption and energy consumption; while the benzaldehyde production process The toluene chlorination hydrolysis method is mostly used, which consumes a large amount of chlorine, acid and alkali, and the discharge seriously pollutes the environment, and the obtained benzaldehyde contains a small amount of chlorine, so its application in perfumery, medicine and other industries is limited. Chlorine-free benzaldehyde is usually obtained as a by-product of benzoic acid prepared by oxidation of toluene, and its production capacity is far from meeting market demand. In addition, cyclic carbonate is also a very important chemical product. It has good biodegradability, solubility and other physical properties. It is a good clean polar solvent and can be used in the production of phenolic resin and polycarbonate synthesis. , synthesis of thermosetting resins, synthesis of thermal recording materials, as well as electrolytes for high-energy density batteries (such as lithium-ion batteries) and capacitors, metal extractants, cosmetic additives and chemical intermediates, etc., and are expensive.

Contents of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art. For this reason, an object of the present invention is to propose a kind of styrene oxidation co-production method of benzaldehyde, styrene oxide and styrene cyclic carbonate.

Another object of the present invention is to propose a device for the oxidation of styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate.

According to the embodiment of the first aspect of the present invention, the method for oxidizing styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate comprises the following steps: A) mixing styrene, a solvent and a catalyst, and adding an oxidizing agent for oxidation react to obtain a reaction feed liquid and a mixed gas, the reaction feed liquid contains benzaldehyde and styrene oxide, and the mixed gas contains formaldehyde; B) separate the reaction feed liquid to obtain benzaldehyde and styrene oxide; C) subjecting the mixed gas to catalytic oxidation treatment to convert formaldehyde into carbon dioxide and water; and D) reacting the mixed gas containing carbon dioxide with a part of styrene oxide to produce styrene cyclic carbonate.

The method for oxidizing styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate according to the embodiment of the present invention has the advantages of high economic benefit and no environmental pollution.

In addition, the method for oxidizing styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate according to the embodiment of the present invention may also have the following additional technical features:

According to one embodiment of the present invention, styrene, solvent, catalyst and oxidant are added into the jet reactor and sprayed circularly in the jet reactor, so as to carry out the oxidation reaction in the jet reactor, preferably Preferably, the solvent is selected from at least one of DMF, cyclohexanone, 1,3-dioxane and 1,4-dioxane, and the catalyst is selected from cobalt acetate, cobalt naphthenate, acetic acid At least one of manganese, Co-ZSM-5, and Mn-X, and the oxidizing agent is selected from at least one of oxygen, oxygen-enriched air and air.

According to an embodiment of the present invention, the step B) includes: B-1) standing the reaction feed liquid to allow the catalyst to precipitate, and separating the precipitated catalyst from the reaction feed liquid; and B-2) The reaction feed liquid is rectified to obtain benzaldehyde, styrene oxide, solvent and unreacted styrene respectively.

According to an embodiment of the present invention, in the step B-2), the rectification is vacuum rectification, the operating pressure of the vacuum rectification is 100mmHg-200mmHg, and the temperature of the tower bottom is 130°C-140°C ℃, the reflux ratio is 8.0-13.0, and the number of theoretical plates is 40-60. Among them, the solvent and unreacted styrene are extracted from the top of the rectification tower, and benzaldehyde is extracted from the side line of the rectification tower to oxidize benzene Ethylene is withdrawn from the side draw of the rectification column.

According to an embodiment of the present invention, the step D) includes: D-1) removing water in the mixed gas containing carbon dioxide; and D-2) combining the water-removed mixed gas containing carbon dioxide with a part Styrene oxidation reacts to form styrene cyclic carbonate and obtains an oxygen-containing gas.

According to an embodiment of the present invention, the oxygen-containing gas obtained from the step D-2) is used as an oxidant to participate in the oxidation reaction of the step A).

According to one embodiment of the present invention, the mixed gas containing carbon dioxide and a part of styrene oxide are added to the jet reactor and sprayed in a cycle in the jet reactor, so as to react in the jet reactor and Formation of styrene cyclic carbonate.

According to the embodiment of the second aspect of the present invention, the device for the co-production of benzaldehyde, styrene oxide and styrene cyclic carbonate by oxidation of styrene comprises: a first reactor, and the first reactor has a feed port and a discharge port and the first exhaust port; a rectification tower, the rectification tower has a feed port, a tower top discharge port, a first side discharge port and a second side discharge port, the feed port of the rectification tower Communicated with the discharge port of the first reactor; catalytic oxidation reactor, the catalytic oxidation reactor has a feed port and a discharge port, the feed port of the catalytic oxidation reactor is connected to the first reactor The first exhaust port of the rectification tower is communicated; With the second reactor, the second reactor has a feed port, a discharge port and a second exhaust port, and the first side discharge port of the rectification tower and the second One of the side discharge ports communicates with the feed port of the second reactor, and the discharge port of the catalytic oxidation reactor communicates with the feed port of the second reactor.

The device for oxidizing styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate according to the embodiment of the present invention has the advantages of high economic benefit and no environmental pollution.

According to an embodiment of the present invention, the first reactor is a first jet reactor, and the first jet reactor includes: a first body having a first reaction chamber inside the first body, the first The wall of the reaction chamber is provided with a feed inlet, a feed outlet, a circulation outlet and a first exhaust port; and a first injector, at least a part of the first injector extends into the first reaction chamber Inside, the first injector has a circulation feed port, an oxygen-containing gas inlet, and an injection port located in the first reaction chamber, and the circulation feed port of the first injector and the circulation of the first body The outlets are connected through a first pipeline, wherein a circulation pump, a flow meter and a first heat exchanger are arranged on the first pipeline.

According to an embodiment of the present invention, the second reactor is a second jet reactor, and the second jet reactor includes: a second body, a second reaction chamber inside the second body, and a second reaction chamber inside the second body. The wall of the reaction chamber is provided with a styrene oxide inlet, a discharge port, a circulation discharge port and a second exhaust port; and a second injector, at least a part of which extends into the second reaction chamber. In the cavity, the second injector has a circulation feed port, a gas inlet and an injection port located in the second reaction chamber, the circulation feed port of the second injector is connected with the circulation outlet of the second body The feed port is connected to each other through a second pipeline, wherein a circulation pump, a flow meter and a second heat exchanger are arranged on the second pipeline, and the styrene oxide inlet is connected to the first side discharge port and the first side outlet of the rectifying tower. One of the second side outlets is connected, the gas inlet is connected with the outlet of the catalytic oxidation reactor, preferably, the second exhaust port is connected with the oxygen-containing gas inlet.

According to an embodiment of the present invention, the device for the co-production of benzaldehyde, styrene oxide and styrene cyclic carbonate by the oxidation of styrene further includes: a separation tank, the separation tank has a feed inlet, a first discharge outlet and the second discharge port, the feed port of the separation tank is communicated with the discharge port of the first reactor, and the first discharge port of the separation tank is communicated with the feed port of the rectification tower; The third heat exchanger, the third heat exchanger has a feed port and a feed port, the feed port of the third heat exchanger communicates with the first exhaust port of the first reactor, the The discharge port of the third heat exchanger communicates with the feed port of the catalytic oxidation reactor; It communicates with the feed port of the catalytic oxidation reactor, and the feed port of the water eliminator communicates with the feed port of the second reactor.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and comprehensible from the description of the embodiments in conjunction with the following drawings, wherein:

Fig. 1 is a schematic structural view of a device for oxidizing styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate according to an embodiment of the present invention.

A device 100 for the oxidation of styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate;

First reactor F-01, first body 11, first reaction chamber 111, first injector 12, circulation pump P-01, flow meter L-01, first heat exchanger C-01, valve D-01 , The third heat exchanger E-01;

Rectification tower T, tower top condenser H-01, tower bottom reboiler H-02;

Catalytic oxidation reactor R-01;

Second reactor F-02, second body 21, second injector 22, second reaction chamber 211, circulation pump P-02, flow meter L-02, second heat exchanger C-02, valve D-02 ;

Water eliminator R-02;

Separation tank V-01;

Condenser E-02.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", " The orientations or positional relationships indicated by "vertical", "horizontal", "top", "bottom", "inner" and "outer" are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and Simplified descriptions, rather than indicating or implying that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and thus should not be construed as limiting the invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention in specific situations.

The invention provides a method for oxidizing styrene to co-produce benzaldehyde, oxidized styrene and styrene cyclic carbonate. The method for styrene oxidation co-production benzaldehyde, styrene oxide and styrene cyclic carbonate according to the embodiment of the present invention comprises the following steps:

A) mixing styrene, a solvent and a catalyst, and adding an oxidizing agent to carry out an oxidation reaction to obtain a reaction feed liquid and a mixed gas, the reaction feed liquid contains benzaldehyde and styrene oxide, and the mixed gas contains formaldehyde;

B) separating the reaction feed liquid to obtain benzaldehyde and styrene oxide;

C) catalytic oxidation of the gas mixture to convert formaldehyde into carbon dioxide and water; and

D) The mixed gas containing carbon dioxide is reacted with a part of styrene oxide to produce styrene cyclic carbonate.

At present, the research of styrene oxidation is mainly through the development of high-performance catalysts to improve the reaction conversion and selectivity. However, although many catalysts have good catalytic effects, the preparation process is complicated, the cost is high, and the industrialization is difficult. After in-depth research by the inventors, it is found that when styrene epoxidation is used to synthesize styrene oxide, different by-products, such as benzaldehyde and phenylacetaldehyde, will be produced due to different reaction conditions. Among them, the oxidation reaction of styrene as raw material It is very sensitive to oxygen, and the amount of oxygen and gas-liquid contact conditions have an important impact on the reaction process.

During the epoxidation of styrene to synthesize styrene oxide, formaldehyde, carbon dioxide and water are continuously generated during the reaction process, resulting in a decrease in the oxygen content in the gas phase and affecting the reaction process. Therefore, a certain amount of gas needs to be discharged regularly to increase the oxygen content in the gas phase. However, the emitted formaldehyde and the VOCs in it must be treated to avoid environmental pollution and explosion hazards.

According to the method of oxidation of styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate according to the embodiment of the present invention, formaldehyde is converted into carbon dioxide and water, and carbon dioxide is used to react with a part of styrene oxide so as to generate The value of styrene cyclic carbonate, that is, carbon dioxide is consumed by partial oxidation products to produce products with higher added value.

In this way, not only the generated formaldehyde and carbon dioxide can be removed, but also the tail gas containing formaldehyde can be effectively treated to avoid environmental pollution and explosion hazards, as well as to ensure the oxygen concentration required for the oxidation of styrene (that is, to increase the oxygen content in the gas phase), thereby reducing styrene By-products produced during the synthesis of styrene oxide by epoxidation, and styrene cyclic carbonate with higher added value can be obtained. Therefore, the co-production of styrene oxide, chlorine-free benzaldehyde and styrene cyclic carbonate by oxygen oxidation of styrene meets the requirements of green chemistry and has great industrial prospects. The whole reaction process is economical and green, and benzaldehyde with a purity of more than 98.50% (wt) and styrene oxide and styrene cyclic carbonate with a purity of more than 98.00% (wt) can be obtained.

Therefore, the method for oxidizing styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate according to the embodiment of the present invention has the advantages of high economic benefit and no environmental pollution.

Referring to FIG. 1 , a device 100 for oxidizing styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate according to an embodiment of the present invention will be described below. As shown in Figure 1 , the device 100 for the co-production of benzaldehyde, styrene oxide and styrene cyclic carbonate according to the embodiment of the present invention includes a first reactor F-01, a rectifying tower T, a catalytic oxidation reaction Reactor R-01 and the second reactor F-02.

The first reactor F-01 has a feed port, a feed port and a first exhaust port. The rectification tower T has a feed inlet, a tower top outlet, a first side outlet and a second side outlet, and the feed inlet of the rectification tower T communicates with the outlet of the first reactor F-01 . The catalytic oxidation reactor R-01 has a feed port and a discharge port, and the feed port of the catalytic oxidation reactor R-01 communicates with the first exhaust port of the first reactor F-01. The second reactor F-02 has a feed port, a discharge port and a second exhaust port, and one of the first side discharge port and the second side discharge port of the rectification tower T is connected with the second reactor F-02 The feed port of the catalytic oxidation reactor R-01 is communicated with the feed port of the second reactor F-02.

The device 100 for oxidizing styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate according to an embodiment of the present invention is provided with a catalytic oxidation reactor R communicated with the first exhaust port of the first reactor F-01 -01, so that the formaldehyde generated by the reaction can be decomposed into carbon dioxide and water, and by setting the second reactor F-02 in cooperation with the rectification tower T and the catalytic oxidation reactor R-01, carbon dioxide and styrene oxide can be made reaction in order to obtain styrene cyclic carbonate with higher added value.

In this way, not only the generated formaldehyde and carbon dioxide can be removed, but also the tail gas containing formaldehyde can be effectively treated to avoid environmental pollution and explosion hazards, as well as to ensure the oxygen concentration required for the oxidation of styrene (that is, to increase the oxygen content in the gas phase), thereby reducing styrene By-products produced during the synthesis of styrene oxide by epoxidation, and styrene cyclic carbonate with higher added value can be obtained.

Therefore, the device 100 for oxidizing styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate according to the embodiment of the present invention has the advantages of high economic benefit and no environmental pollution.

As shown in Fig. 1, the device 100 of styrene oxidation co-production benzaldehyde, styrene oxide and styrene cyclic carbonate according to some embodiments of the present invention includes a separation tank, a first reactor F-01, a separation tank V -01, rectification tower T, catalytic oxidation reactor R-01, second reactor F-02 and water remover R-02.

The first reactor F-01 is a first jet reactor, which includes a first body 11 and a first injector 12 . The first body 11 has a first reaction chamber 111 inside, and the wall of the first reaction chamber 111 is provided with a feed inlet, a feed outlet, a circulation outlet and a first exhaust outlet. At least a part of the first injector 12 protrudes into the first reaction chamber 111 , and the first injector 12 has a circulation feed port, an oxygen-containing gas inlet and an injection port located in the first reaction chamber 111 . Wherein, the circulation inlet of the first ejector 12 is connected with the circulation outlet of the first body 11 through the first pipeline 3, and the first pipeline 3 is provided with a circulation pump P-01, a flow meter L-01 and The first heat exchanger C-01.

Styrene, solvent and catalyst (or its load) are mixed and sent to the first reactor F-01 along the pipeline 1, and then the raw materials are sent to the first reactor F-01 through the first pipeline 3 under the action of the circulation pump P-01 In an injector 12, the reaction gas (oxygen-containing gas) is input into the pipeline 2, and the flow rate of the circulating liquid is regulated by the flow meter L-01 and the valve D-01 arranged on the first pipeline 3, and the first heat exchange Device C-01 is used to control the temperature of the circulating liquid. Advantageously, a sampling point is provided on the first pipeline 3 for detecting the reaction condition. The reacted gas is discharged from the first reactor F-01 through the pipeline 4, and the organic matter in the gas is liquefied and returned to the first reactor F-01 through the third heat exchanger E-01 (condenser).

That is, styrene, solvent, catalyst, and oxidant are added to the injection reactor (the first reactor F-01) and cyclic injection is performed in the first reactor F-01 so that in the first reactor F-01 01 to carry out the oxidation reaction. Advantageously, the discharge port of the first body 11 and the circulation discharge port are the same opening, and the first heat exchanger C-01 is a condenser.

The existing styrene oxidation reaction to prepare styrene oxide is carried out in a stirred reactor, a bubbling reactor or a stirred bubbling reactor. Stirred reactors, bubble reactors, and stirred bubble reactors have limited gas-liquid contact areas, resulting in long reaction times, high energy consumption, high oxygen consumption, and poor safety. In contrast, the first reactor F-01 is liquid phase-driven mixing, without rigid friction, and has high safety. The gas phase above the liquid surface can be sent to the bottom of the first reaction chamber 111 for repeated reactions, and the oxygen utilization rate High, and the mixing effect of material and liquid is good, which is beneficial to enhance mass transfer and heat transfer, speed up the reaction rate, improve the concentration and temperature distribution, reduce the occurrence of side reactions, and improve the selectivity of the reaction.

That is to say, according to the device 100 of styrene oxidation co-production of benzaldehyde, styrene oxide and styrene cyclic carbonate according to the embodiment of the present invention, the first reactor F-01 is the first injection reactor, so that not only can Promote the gas-liquid reaction, speed up the reaction rate, reduce side reactions, improve concentration and temperature distribution, simplify operation, improve safety, and increase product yield.

Advantageously, the solvent is selected from at least one of DMF, cyclohexanone, 1,3-dioxane and 1,4-dioxane, and the catalyst may be a metal salt catalyst selected from At least one of cobalt acetate, cobalt naphthenate, manganese acetate, Co-ZSM-5, and Mn-X, and the oxidizing agent is selected from at least one of oxygen, oxygen-enriched air and air.

The separation tank V-01 has a feed port, a first discharge port and a second discharge port, the feed port of the separation tank V-01 communicates with the discharge port of the first reactor F-01, and the separation tank V-01 The first discharge port of the first outlet communicates with the feed port of the rectifying tower T. After the reaction, the reaction feed liquid (styrene, solvent, catalyst, benzaldehyde, styrene oxide, etc.) enters the separation tank V-01 through the pipeline 5, and the reaction feed liquid is left in the separation tank V-01 to make the catalyst precipitate , separating the precipitated catalyst from the reaction feed liquid so as to recover and reuse the precipitated catalyst. Wherein, the second outlet of the separation tank V-01 can be used to remove the precipitated catalyst.

The reaction feed liquid that will remove this catalyzer is transported in rectification tower T, so that this reaction feed liquid is rectified in rectification tower T, and obtain benzaldehyde, styrene oxide, solvent and unreacted styrene respectively . Specifically, the separated tank V-01 enters the rectifying tower T along the pipeline 6 after standing still in the separated tank V-01. The rectification tower T operates under reduced pressure, that is, the rectification is vacuum rectification. The operating pressure of the vacuum distillation is controlled at 100mmHg-200mmHg, the temperature of the bottom of the rectification tower T is 130°C-140°C, the number of theoretical plates of the rectification tower T is 40-60, and the reflux of the rectification tower T The ratio is 8.0-13.0. The solvent and unreacted styrene are extracted from the top of the rectifying tower T and returned to the first reactor F-01 along the pipeline 7, and the benzaldehyde is extracted from the side line of the rectifying tower T along the pipeline 8, and oxidized Styrene is extracted from the side line of rectification tower T along pipeline 9. Catalysts, solvents and unreacted styrene can be recycled and reused after separation, which greatly saves costs and increases the yield per unit of raw materials. Specifically, the outlet at the top of the rectifying tower T communicates with the feed port of the first reactor F-01.

As shown in Figure 1, the rectifying column T is equipped with a top condenser H-01 and a bottom reboiler H-02.

In some examples of the present invention, as shown in FIG. 1 , the second reactor F- 02 is a second jet reactor, and the second jet reactor includes a second body 21 and a second injector 22 . The second body 21 has a second reaction chamber 211 inside, and the wall of the second reaction chamber 211 is provided with a styrene oxide inlet, a discharge port, a circulation discharge port and a second exhaust port. At least a part of the second ejector 22 stretches into the second reaction chamber 211, the second ejector 22 has a circulation feed port, a gas inlet and an injection port positioned at the second reaction chamber 211, the circulation of the second ejector 22 The feed port is connected with the circulation discharge port of the second body 21 through the second pipeline 13 . Wherein, the second pipeline 13 is provided with a circulating pump P-02, a flow meter L-02 and a second heat exchanger C-02, the styrene oxide inlet of the second reactor F-02 is connected with the first One side outlet is connected with one of the second side outlet, and the gas inlet of the second reactor F-02 is connected with the outlet of the catalytic oxidation reactor R-01.

A part of the styrene oxide in the pipeline 9 enters the second reactor F-02 through the pipeline 12 to react with carbon dioxide to produce styrene cyclic carbonate, and the rest of the styrene oxide in the pipeline 9 is sent from the pipeline to the storage tank. Can. Advantageously, an appropriate amount of solvent and catalyst is replenished from the pipeline 12 into the second reactor F-02. Styrene oxide, solvent and catalyst in the second reactor F-02 are sent into the second injector 22 through the second pipeline 13 under the effect of the circulation pump P-02, and the The flow meter L-02 and the valve D-02 are used to regulate the flow of the circulating liquid, and the second heat exchanger C-02 is used to control the temperature of the circulating liquid.

In other words, the mixed gas containing carbon dioxide and a part of styrene oxide are fed into the injection reactor (the second reactor F-02) and cyclically injected in the second reactor F-02, so that in the second reactor F -02 to react and generate styrene cyclic carbonate.

Advantageously, the discharge port of the second body 21 and the circulation discharge port are the same opening, the second heat exchanger C-02 is a condenser, and the second exhaust port of the second reactor F-02 is connected to the first reactor The oxygen-containing gas inlet of F-01 is connected. Thus, the gas containing higher concentration of oxygen obtained after the reaction in the second reactor F-02 can circulate along the pipeline 14 into the first reactor F-01 to continue to participate in the styrene oxidation reaction. More advantageously, the pipeline 14 is provided with a condenser E-02, and the gas containing a relatively high concentration of oxygen enters the first reactor F-01 after being cooled by the condenser E-02.

As shown in Fig. 1, in one embodiment of the present invention, the device 100 of styrene oxidation co-production benzaldehyde, styrene oxide and styrene cyclic carbonate further includes the third heat exchanger E-01, the third heat exchanger Heater E-01 has a feed port and a feed port, the feed port of the third heat exchanger E-01 communicates with the first exhaust port of the first reactor F-01, and the third heat exchanger E-01 The outlet of the feed port communicates with the feed port of the catalytic oxidation reactor R-01. The gas discharged from the first reactor F-01 can thus be cooled by means of the third heat exchanger E-01. Wherein the gas discharged from the first reactor F-01 mainly contains oxygen, carbon dioxide, a small amount of formaldehyde and water.

After being cooled, the gas discharged from the first reactor F-01 enters the catalytic oxidation reactor R-01, and undergoes catalytic oxidation treatment in the catalytic oxidation reactor R-01 to remove formaldehyde.

As shown in Figure 1, the water eliminator R-02 has a feed port and a feed port, the feed port of the water eliminator R-02 communicates with the discharge port of the catalytic oxidation reactor R-01, and the water eliminator R- The discharge port of 02 is connected with the feed port of the second reactor F-02, so that the water in the mixed gas containing carbon dioxide discharged from the catalytic oxidation reactor R-01 is removed by the water eliminator R-02. The gas discharged from the water eliminator R-02 enters the second reactor F-02 through the pipeline 11, and in the second reactor F-02, the mixed gas containing carbon dioxide after dehydration and a part of the oxidized benzene Ethylene reacts to produce styrene cyclic carbonate and an oxygen-containing gas.

Specifically, the outlet of the water eliminator R-02 communicates with the gas inlet of the second injector 22 of the second reactor F-02. In other words, the feed port of the second reactor F-02 includes the gas inlet of the second injector 22 and the styrene oxide inlet of the second body 21 . In the second reactor F-02, carbon dioxide reacts with styrene oxide to form styrene cyclic carbonate. Wherein, a sampling point is provided on the pipeline 13 for detecting the reaction condition, and the fully reacted cyclic carbonate is extracted from the pipeline 15 .

In a specific example of the present invention, styrene, DMF, and catalyst cobalt naphthenate are sent into the first reactor F-01 along pipeline 1, mixed and heated to 90°C. Feed oxygen-containing gas into the first reactor F-01, after the oxygen-containing gas fills the entire first reactor F-01, turn on the circulation pump P-01, and control the circulation through the valve D-01 and the flow meter L-01 flow of liquid.

Oxygen-containing gas continuously enters the first reactor F-01 and is discharged from the first exhaust port of the first reactor F-01. oxygen gas. After a period of time, take a sample from the sampling port of pipeline 3 and check the reaction situation. After the reaction is completed, the reaction feed liquid enters the separation tank V-01 through pipeline 5, and the catalyst precipitates after standing so that it can be recycled and reused. The reaction feed liquid after standing contains 3.8wt% styrene, 2.4wt% DMF, benzaldehyde 11.9wt%, styrene oxide 15.7wt%, other components 6.2wt%.

The reaction feed liquid after standing still is sent into rectifying tower T along pipeline 6 with the flow rate of 10000kg/h. The rectification tower T is a decompression operation, the operating pressure of the rectification tower T is controlled at 140mmHg, the temperature of the bottom of the rectification tower T is controlled at about 138°C, and the number of theoretical plates of the rectification tower T is 54. The tower diameter of T is 2.1m, and the feeding position is at the 22nd tray. After separation, DMF and unreacted styrene enter the first reactor F-01 again from the top of the tower along the pipeline 7, and partial reflux is realized at the top of the tower with a reflux ratio of 8.0. Benzaldehyde and styrene oxide are extracted from the side stream respectively. Among them, benzaldehyde is extracted from the 46th tray with a flow rate of 1059.6kg/h, and the purity of benzaldehyde reaches 98.6%. Styrene oxide is extracted from the 35th tray with a flow rate of 1459.3kg/h. The purity reaches 98.07%.

Pass a part of styrene oxide into the second reactor F-02, and add imidazole-type ionic liquid. The formaldehyde-containing gas discharged from the first reactor F-01 is catalytically decomposed to generate CO ₂ and H ₂ O, wherein H ₂ O is removed. The treated mixed gas (containing O ₂ and CO ₂ ) enters the second reactor F-02 to participate in the reaction. Under the action of ionic liquid, styrene oxide and CO ₂ are added to form styrene cyclic carbonate. This process consumes a certain amount of CO ₂ . After a period of time, the reaction can be monitored through the sampling port until the reaction is complete. The O2 in the gas discharged from the second reactor F- ₀₂ increases, and is recycled to the first reactor F-01 to continue to participate in the oxidation reaction.

According to the embodiment of the present invention, the device 100 and method for the co-production of benzaldehyde, styrene oxide and styrene cyclic carbonate by oxidation of styrene have the following advantages: the oxidation reaction raw material of styrene is easy to obtain, and the cost is low; Process intensification of the reactor, simple operation, good safety, high product yield; unreacted oxidizing gas can be continuously recycled, and _CO2 obtained from formaldehyde oxidation can be consumed by partial oxidation products to generate higher value-added The product, the whole reaction process is economical and green; the catalyst, solvent and unreacted styrene can be recycled and reused after separation, which greatly saves costs and improves the yield of unit raw materials; the target product is obtained through vacuum distillation separation, and benzaldehyde with a purity of more than 98.50wt% and styrene oxide and styrene cyclic carbonate with a purity of more than 98.00wt% can be obtained.

In the description of this specification, references to the terms "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific examples," or "some examples" are intended to mean that the implementation A specific feature, structure, material, or characteristic described by an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications, substitutions and modifications can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the invention is defined by the claims and their equivalents.

Claims (13)

1. a method for styrene oxidation co-production benzaldehyde, styrene oxide and styrene cyclic carbonate, is characterized in that, comprises the following steps: A) mixing styrene, a solvent and a catalyst, and adding an oxidant to carry out an oxidation reaction to obtain a reaction feed liquid and a mixed gas, the reaction feed liquid contains benzaldehyde and styrene oxide, and the mixed gas contains formaldehyde; B) separating the reaction feed liquid to obtain benzaldehyde and styrene oxide; C) performing catalytic oxidation treatment on the mixed gas so as to convert formaldehyde into carbon dioxide and water; and D) The mixed gas containing carbon dioxide is reacted with a part of styrene oxide to produce styrene cyclic carbonate. 2. the method for styrene oxidation co-production benzaldehyde, styrene oxide and styrene cyclic carbonate according to claim 1, is characterized in that, styrene, solvent, catalyst and oxidizing agent are joined in jet reactor and Circular injection is carried out in the jet reactor in order to carry out the oxidation reaction in the jet reactor. 3. according to the method for the described styrene oxidation coproduction benzaldehyde of claim 2, styrene oxide and styrene cyclic carbonate, it is characterized in that, described solvent is selected from DMF, cyclohexanone, 1,3-diox At least one of pentacyclic and 1,4-dioxane, the catalyst is selected from at least one of cobalt acetate, cobalt naphthenate, manganese acetate, Co-ZSM-5, manganese halide, the oxidant At least one of oxygen, oxygen-enriched air and air is selected. 4. the method for styrene oxidation co-production benzaldehyde, styrene oxide and styrene cyclic carbonate according to claim 1, is characterized in that, described step B) comprises: B-1) standing the reaction feed liquid to allow the catalyst to precipitate, and separating the precipitated catalyst from the reaction feed liquid; and B-2) Rectifying the reaction feed liquid to obtain benzaldehyde, styrene oxide, solvent and unreacted styrene respectively. 5. the method for styrene oxidation co-production benzaldehyde, styrene oxide and styrene cyclic carbonate according to claim 4, is characterized in that, in described step B-2), described rectification is to reduce Pressure rectification, the operating pressure of the vacuum rectification is 100mmHg-200mmHg, the temperature of the tower bottom is 130°C-140°C, the reflux ratio is 8.0-13.0, and the number of theoretical plates is 40-60 pieces, wherein the solvent and unreacted The styrene is extracted from the top of the rectification tower, the benzaldehyde is extracted from the side line of the rectification tower, and the styrene oxide is extracted from the side line of the rectification tower. 6. the method for styrene oxidation co-production benzaldehyde, styrene oxide and styrene cyclic carbonate according to claim 1, is characterized in that, described step D) comprises: D-1) removing water from said gas mixture containing carbon dioxide; and D-2) The mixed gas containing carbon dioxide after water removal is reacted with a part of styrene oxide to generate styrene cyclic carbonate to obtain an oxygen-containing gas. 7. the method for styrene oxidation co-production benzaldehyde, styrene oxide and styrene cyclic carbonate according to claim 6, is characterized in that, by described step D-2) the gas containing oxygen obtained as oxidant Participate in the oxidation reaction of step A). 8. the method for styrene oxidation co-production benzaldehyde, styrene oxide and styrene cyclic carbonate according to claim 1, is characterized in that, the described mixed gas containing carbon dioxide and a part of styrene oxide are added to injection Circular injection is carried out in the reactor and in the injection reactor so that the reaction takes place in the injection reactor and produces styrene cyclic carbonate. 9. A device for the oxidation of styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate, characterized in that it comprises: A first reactor, the first reactor has a feed port, a feed port and a first exhaust port; A rectification tower, the rectification tower has a feed inlet, a tower top outlet, a first side outlet and a second side outlet, the feed inlet of the rectification tower is connected to the first reactor The discharge port is connected; a catalytic oxidation reactor, the catalytic oxidation reactor has a feed port and a discharge port, the feed port of the catalytic oxidation reactor communicates with the first exhaust port of the first reactor; and The second reactor, the second reactor has a feed port, a feed port and a second exhaust port, one of the first side discharge port and the second side discharge port of the rectification column is connected to the The feed port of the second reactor is connected, and the discharge port of the catalytic oxidation reactor is connected with the feed port of the second reactor. 10. the device of styrene oxidation co-production benzaldehyde, styrene oxide and styrene cyclic carbonate according to claim 9, is characterized in that, described first reactor is the first injection reactor, and described first A jet reactor comprising: A first body, the first body has a first reaction chamber inside, and the wall of the first reaction chamber is provided with a feed port, a discharge port, a circulation discharge port and a first exhaust port; and The first injector, at least a part of the first injector extends into the first reaction chamber, the first injector has a circulation feed port, an oxygen-containing gas inlet and is located in the first reaction chamber The injection port of the first injector is connected with the circulation outlet of the first body through a first pipeline, wherein a circulation pump, a flow meter and a first Heat Exchanger. 11. the device of styrene oxidation co-production benzaldehyde, styrene oxide and styrene cyclic carbonate according to claim 10, is characterized in that, described second reactor is the second injection reactor, and described second The two jet reactors consist of: A second body, the second body has a second reaction chamber, and the wall of the second reaction chamber is provided with a styrene oxide inlet, a discharge port, a circulation discharge port and a second exhaust port; and The second injector, at least a part of the second injector protrudes into the second reaction chamber, the second injector has a circulation feed port, a gas inlet, and an injection nozzle located in the second reaction chamber The circulation feed port of the second ejector is connected with the circulation discharge port of the second body through a second pipeline, wherein a circulation pump, a flow meter and a second heat exchanger are arranged on the second pipeline The styrene oxide inlet communicates with one of the first side outlet and the second side outlet of the rectification tower, and the gas inlet communicates with the outlet of the catalytic oxidation reactor. 12. The device for oxidizing styrene to co-produce benzaldehyde, styrene oxide and styrene cyclic carbonate according to claim 11, characterized in that, the second exhaust port communicates with the oxygen-containing gas inlet. 13. the device of styrene oxidation co-production benzaldehyde, styrene oxide and styrene cyclic carbonate according to claim 9, is characterized in that, further comprises: A separation tank, the separation tank has a feed port, a first discharge port and a second discharge port, the feed port of the separation tank communicates with the discharge port of the first reactor, the separation tank The first discharge port communicates with the feed port of the rectifying tower; The third heat exchanger, the third heat exchanger has a feed port and a feed port, the feed port of the third heat exchanger communicates with the first exhaust port of the first reactor, the The discharge port of the third heat exchanger communicates with the feed port of the catalytic oxidation reactor; and Water eliminator, the water eliminator has a feed port and a discharge port, the feed port of the water eliminator communicates with the discharge port of the catalytic oxidation reactor, and the discharge port of the water eliminator communicates with the discharge port of the catalytic oxidation reactor The feed port of the second reactor is connected.