Ethylbenzene enhanced oxidation reaction system

Abstract

The utility model provides an ethylbenzene enhanced oxidation reaction system. The system comprises: an oxidation reactor, wherein the oxidation reactor is connected with a gas inlet pipeline for inputting a gas-phase raw material and a liquid inlet pipeline for inputting a liquid-phase raw material; a product outlet is formed in the side wall of the oxidation reactor; the first enhanced mass transfer unit is arranged in the oxidation reactor, the gas inlet pipeline is connected with the first enhanced mass transfer unit, and the gas-phase raw material in the gas inlet pipeline enters the oxidation reactor after being treated by the first enhanced mass transfer unit, so that the mass transfer effect between the gas-phase raw material and the liquid-phase raw material is enhanced; an inlet and an outlet of the heat exchange pipeline are both communicated with the oxidation reactor, and the inlet of the heat exchange pipeline is arranged below the outlet of the heat exchange pipeline in the vertical direction; a first heat exchanger is arranged on the heat exchange pipeline. According to the scheme, the reaction efficiency and the product yield of the ethylbenzene peroxidation reaction can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of ethylbenzene oxidation reaction, in particular to an ethylbenzene enhanced oxidation reaction system. Background Art

[0002] The propylene oxide-styrene (PO / SM) co-production process, also known as the co-oxidation process, is an important chemical production technology. The PO / SM co-production process technology route mainly uses propylene and ethylbenzene as raw materials and adopts the co-oxidation process to produce propylene oxide and styrene product monomers. The process first directly oxidizes ethylbenzene with air or oxygen to produce ethylbenzene hydroperoxide (EBHP), and then EBHP and propylene undergo epoxidation reaction under the action of a molybdenum-based catalyst to produce methylbenzyl alcohol (phenylethanol) and propylene oxide. The epoxidation reaction liquid is distilled to obtain propylene oxide (PO) products, and phenylethanol is dehydrated at 260°C and normal pressure to produce styrene (SM) products.

[0003] In the related art, ethylbenzene oxidation reaction is usually carried out in multiple (for example, two) non-catalytic, liquid-phase oxidation reactors in series. The concentration of EBHP in the reaction product obtained after passing through multiple oxidation reactors is usually only 8-10wt%, and the reaction efficiency is low.

[0004] In view of this, the present utility model is proposed. Utility Model Content

[0005] The first purpose of the utility model is to provide an ethylbenzene enhanced oxidation reaction system, which helps to improve the reaction efficiency and product yield of the ethylbenzene peroxidation reaction by arranging a first enhanced mass transfer unit in the oxidation reactor and arranging a heat exchange pipeline connected to the oxidation reactor. The concentration of ethylbenzene hydrogen peroxide in the reaction product is relatively high, which can meet the needs of downstream production.

[0006] The second purpose of the utility model is to provide an ethylbenzene enhanced oxidation reaction method, which can improve the reaction efficiency and product yield of the ethylbenzene peroxidation reaction by applying the above system to carry out the ethylbenzene peroxidation reaction.

[0007] In order to achieve the above-mentioned purpose of the utility model, the following technical solutions are adopted:

[0008] The utility model provides an ethylbenzene enhanced oxidation reaction system, comprising: an oxidation reactor, the oxidation reactor is connected with an air inlet pipeline for inputting gas phase raw materials and a liquid inlet pipeline for inputting liquid phase raw materials; a product outlet is arranged on the side wall of the oxidation reactor; a first enhanced mass transfer unit is arranged inside the oxidation reactor, the air inlet pipeline is connected to the first enhanced mass transfer unit, the gas phase raw materials in the air inlet pipeline enter the oxidation reactor after being processed by the first enhanced mass transfer unit, so as to enhance the mass transfer effect between the gas phase raw materials and the liquid phase raw materials; a heat exchange pipeline, the inlet and outlet of the heat exchange pipeline are both connected with the oxidation reactor, and the inlet of the heat exchange pipeline is arranged below the outlet of the heat exchange pipeline in the vertical direction; and a first heat exchanger is arranged on the heat exchange pipeline.

[0009] In the related art, ethylbenzene peroxidation is usually carried out in multiple (e.g., two) non-catalytic, liquid-phase series oxidation reactors, and the concentration of EBHP in the reaction product obtained after the multiple oxidation reactors is usually only 8-10wt%. On the one hand, this production system needs to use multiple oxidation reactors, resulting in a large overall space occupation; on the other hand, the concentration of EBHP in the reaction product obtained by this production system is low, the reaction efficiency is low, and due to the low concentration of EBHP, it cannot be directly applied to the downstream (e.g., ethylbenzene hydroperoxide epoxidation), and it is usually necessary to increase the concentration equipment to further concentrate it, which further increases the production cost. In addition, the utility model person has found through research that the reaction of ethylbenzene oxidation to generate hydrogen peroxide has the characteristics of slow reaction rate, temperature sensitivity, large influence of product concentration, medium reaction heat effect, etc., thus, the reactor of the reaction should meet the requirements of large liquid holding capacity, high heat transfer efficiency, stable operation, and easy control of reaction conditions. However, the inventors of the utility model have further found that the liquid phase back-mixing in the reactor with large liquid holding capacity (such as a bubble column reactor) is serious, and the ethylbenzene peroxidation reaction is very sensitive to the concentration of the product EBHP. The large liquid phase back-mixing will reduce the selectivity of the reaction and is not conducive to the control of the reaction. In addition, when the reactor has a large height-diameter ratio, bubbles will coalesce, the bubble dispersion effect will deteriorate, the gas-liquid contact area will be reduced, and the gas-liquid mass transfer efficiency will be affected. In view of the above research, the embodiment of the utility model provides an ethylbenzene enhanced oxidation reaction system, which uses only one oxidation reactor, can reduce the occupied area, and help reduce production costs; by setting a first enhanced mass transfer unit in the oxidation reactor, the gas phase raw material enters the oxidation reactor after being processed by the first enhanced mass transfer unit, thereby increasing the gas-liquid contact area between the gas phase raw material and the liquid phase raw material, improving the gas-liquid mass transfer efficiency, and thus improving the reaction efficiency; by setting a heat exchange pipeline, the first heat exchanger can be used to control the material temperature in the oxidation reactor, prevent the reaction temperature from fluctuating violently due to the heat release of the oxidation reaction, maintain the stability of the reaction temperature, thereby helping to improve the conversion rate and selectivity of the reaction, and improve the yield of the reaction product. In addition, the heat exchange pipeline can play a local stirring role on the material inside the oxidation reactor during the heat exchange process of the material, which helps to make the microbubbles output by the first enhanced mass transfer unit evenly distributed in the oxidation reactor, avoid bubble aggregation, and thus help to further improve the reaction efficiency and product yield. In conclusion, this scheme helps to improve the reaction efficiency and product yield of ethylbenzene peroxidation reaction, and the concentration of ethylbenzene hydroperoxide in the reaction product is relatively high, which can meet the needs of downstream production.

[0010] Preferably, it also includes a circulation pipeline; the inlet of the circulation pipeline is connected to the bottom of the oxidation reactor; the outlet of the circulation pipeline is connected to the oxidation reactor, the outlet of the circulation pipeline is higher than the inlet of the circulation pipeline in the vertical direction and the outlet of the circulation pipeline is lower than the liquid level of the oxidation reactor in the vertical direction; the liquid inlet pipeline is connected to the circulation pipeline, and the liquid raw material in the liquid inlet pipeline enters the oxidation reactor through the circulation pipeline; a second enhanced mass transfer unit is arranged in the circulation pipeline near the outlet of the circulation pipeline, the second enhanced mass transfer unit is connected to the air inlet pipeline, and the gaseous raw material in the air inlet pipeline enters the circulation pipeline after being processed by the second enhanced mass transfer unit, so as to enhance the mass transfer effect between the gaseous raw material and the liquid raw material; the product outlet is higher than the outlet of the circulation pipeline in the vertical direction, and the product outlet is located below the liquid level of the oxidation reactor in the vertical direction.

[0011] In the above preferred solution, the material at the bottom of the oxidation reactor can be extracted by a circulation pipeline and transported back to the oxidation reactor through the outlet of the circulation pipeline, thereby stirring the material in the oxidation reactor, promoting the uniformity of the distribution of microbubbles in the material inside the oxidation reactor, and thus helping to further improve the reaction efficiency and product yield. And by arranging a second enhanced mass transfer unit in the circulation pipeline, the gas phase raw material can be dispersed and crushed by using the conveying power of the gas phase raw material in the air inlet pipeline and the conveying power of the material in the circulation pipeline at the same time, thereby improving the dispersion and crushing effect of the gas phase raw material; the microbubbles output by the second enhanced mass transfer unit can flow back to the oxidation reactor together with the circulating material under the impact of the material in the circulation pipeline, and the microbubbles can be further dispersed and crushed under this impact, and the microbubbles can be more evenly distributed in the circulating material under the impact of the material, avoiding the occurrence of bubble aggregation, thereby helping to further improve the gas-liquid contact area, thereby helping to further improve the reaction efficiency and reaction yield.

[0012] Preferably, a baffle is provided in the oxidation reactor, the top of the baffle is higher than the liquid level of the oxidation reactor in the vertical direction, and the distance between the bottom of the baffle and the bottom of the inner cavity of the oxidation reactor is a preset distance; a circulation channel is formed between the baffle and the side wall of the oxidation reactor, and the outlet of the circulation pipe is connected to the circulation channel.

[0013] In the above preferred embodiment, by setting a baffle, it is possible to prevent the materials circulating back in the circulation pipeline from impacting the materials that have completed the reaction in the oxidation reactor, thereby avoiding back mixing and ensuring that the reaction in the oxidation reactor proceeds in an orderly manner. The circulating materials can flow into the bottom of the oxidation reactor along the circulation channel, which helps to extend the reaction path of this part of the materials, thereby helping to improve the conversion rate of the reaction raw materials.

[0014] Preferably, the distance between the second enhanced mass transfer unit and the inner wall of the oxidation reactor is smaller than the distance between the baffle and the inner wall of the oxidation reactor, and the distance between the baffle and the inner wall of the oxidation reactor is smaller than the distance between the baffle and the first enhanced mass transfer unit; preferably, the second enhanced mass transfer unit is arranged at the outlet of the circulation pipeline; preferably, a side of the baffle close to the side wall of the oxidation reactor is provided with a plurality of protrusions from top to bottom. In this scheme, considering that the material flows faster in the circulation pipeline, some microbubbles in the second enhanced mass transfer unit may not have time to break smaller before being sent to the circulation pipeline, resulting in poor consistency of the microbubble scale of the microbubbles output by the second enhanced mass transfer unit (which can be referred to as the first microbubble flow), and bubbles may coalesce in the process of entering the circulation channel through the circulation pipeline, affecting the contact area between gas and liquid. And because the scale of some microbubbles output by the second enhanced mass transfer unit is greater than the scale of the microbubbles output by the first enhanced mass transfer unit, after these microbubbles enter the inside of the oxidation reactor (here mainly refers to the chamber in the oxidation reactor except the circulation channel), the scale of microbubbles in the oxidation reactor may be inconsistent, and then the gas distribution in the oxidation reactor is uneven, affecting the reaction efficiency. In addition, the rising speed of microbubbles of different scales in the oxidation reactor is different, which may cause the microbubbles of different scales to gather and then further affect the reaction efficiency of ethylbenzene peroxidation. In the scheme of the present embodiment, by specifically setting the relative position relationship between the second enhanced mass transfer unit, the baffle and the first enhanced mass transfer unit, the first microbubble flow can be made to quickly enter the circulation channel, and in the process of the first microbubble flow entering the circulation channel, it collides with the baffle, so that the microbubbles in the first microbubble flow can be further dispersed and broken, avoiding bubble aggregation. At the same time, the microbubbles in the first microbubble flow gradually decrease during the process of entering the oxidation reactor along the circulation channel, and when the microbubbles output by the second enhanced mass transfer unit flow to the vicinity of the first enhanced mass transfer unit, the scale of the microbubbles in the first microbubble flow is almost the same as the scale of the microbubbles output by the first enhanced mass transfer unit, thereby avoiding the reaction efficiency of the ethylbenzene peroxidation reaction being affected by the different scales of the microbubbles. In a further preferred embodiment, the second enhanced mass transfer unit is arranged at the outlet of the circulation pipeline. Thus, the first microbubble flow can be directly input into the circulation channel to avoid the occurrence of bubble aggregation during the flow of the first microbubble flow in the circulation pipeline. In a further preferred embodiment, a plurality of protrusions are sequentially arranged on the baffle from top to bottom, thereby, when the microbubbles output by the second enhanced mass transfer unit flow in the circulation channel, they can collide with these protrusions, so that the microbubbles are further broken, which helps to further reduce the scale difference between the microbubbles output by the second enhanced mass transfer unit and the microbubbles output by the first enhanced mass transfer unit.

[0015] Preferably, a second heat exchanger is provided on the circulation pipeline, and the material in the circulation pipeline is circulated to the oxidation reactor after heat exchange in the second heat exchanger; preferably, a circulation pump is provided on the circulation pipeline, and the circulation pump is located in front of the second heat exchanger along the liquid flow direction in the circulation pipeline.

[0016] The above scheme can control the temperature of the material in the oxidation reactor and maintain the stability of the reaction temperature by arranging a second heat exchanger on the circulation pipeline, thereby helping to further improve the conversion rate and selectivity of the reaction and increase the yield of the reaction product.

[0017] Preferably, there are multiple first intensified mass transfer units, and the multiple first intensified mass transfer units are all lower than the product outlet in the vertical direction; preferably, the multiple first intensified mass transfer units are arranged in sequence from top to bottom in the vertical direction; preferably, the outlets of the multiple first intensified mass transfer units face downward.

[0018] In the above scheme, by setting up a plurality of first enhanced mass transfer units, the efficiency of dispersion and crushing of gas-phase raw materials can be improved; by setting up a plurality of first enhanced mass transfer units in sequence from top to bottom in the vertical direction, it is helpful to improve the uniformity of microbubble distribution in the oxidation reactor, thereby further increasing the gas-liquid contact area. In addition, in one of the above preferred schemes, the outlets of the plurality of first enhanced mass transfer units are downward. It can be understood that in this scheme, the flow direction of the reaction raw materials is from bottom to top, and the final reaction product is discharged from the product outlet above. Therefore, compared with the upper part of the first enhanced mass transfer unit, the concentration of liquid-phase raw materials below the first enhanced mass transfer unit is higher. By adding the microbubbles after the dispersion and crushing of the gas-phase raw materials to the lower part of the first enhanced mass transfer unit, it is helpful to make the liquid-phase raw materials below react more fully with the gas-phase raw materials, thereby further improving the reaction efficiency and product yield.

[0019] Preferably, the product outlet is arranged at the lower part of the oxidation reactor, the liquid inlet pipe is connected to the upper part of the oxidation reactor and the liquid inlet pipe is lower than the liquid level of the oxidation reactor in the vertical direction; the number of the first enhanced mass transfer units is multiple, and the multiple first enhanced mass transfer units are arranged in sequence between the liquid inlet pipe and the product outlet in the vertical direction.

[0020] In the above scheme, by setting up multiple first enhanced mass transfer units, the dispersion and crushing efficiency of the gas phase raw material can be improved; by arranging multiple first enhanced mass transfer units in sequence from top to bottom in the vertical direction, it helps to improve the uniformity of microbubble distribution in the oxidation reactor, thereby further increasing the gas-liquid contact area.

[0021] Preferably, the outlets of the plurality of first enhanced mass transfer units face upward. It is understood that in this solution, the flow direction of the reaction raw materials is from top to bottom, and the final reaction product is discharged from the product outlet at the bottom. Therefore, compared with the bottom of the first enhanced mass transfer unit, the concentration of the liquid raw material at the top of the first enhanced mass transfer unit is higher. By adding the microbubbles after the gas phase raw material is dispersed and crushed to the top of the first enhanced mass transfer unit, it is helpful to make the liquid raw material at the top react more fully with the gas phase raw material, thereby further improving the reaction efficiency and product yield.

[0022] Preferably, there are multiple heat exchange pipes, and the multiple heat exchange pipes are arranged sequentially from top to bottom. By arranging multiple heat exchange pipes sequentially from top to bottom, the solution can more accurately control the reaction temperature in the oxidation reactor, thereby helping to further improve the conversion rate and selectivity of the reaction. In addition, the multiple heat exchange pipes can stir different positions in the oxidation reactor, thereby further improving the uniformity of the microbubble distribution in the oxidation reactor, thereby helping to further improve the reaction efficiency and product yield.

[0023] Preferably, multiple layers of barriers are staggered from top to bottom in the oxidation reactor, and the multiple layers of barriers are located below the liquid surface of the oxidation reactor. This solution can avoid the occurrence of liquid phase backmixing as much as possible by staggering multiple layers of barriers from top to bottom in the oxidation reactor, so that the reaction can proceed more orderly.

[0024] Those skilled in the art can understand that the enhanced mass transfer reactor adopted in the present invention has been embodied in the prior patents of the present invention, such as patents with application numbers CN201610641119.6, CN201610641251.7, CN201710766435.0, CN106187660, CN105903425A, CN109437390A, CN205833127U and CN207581700U. The prior patent CN201610641119.6 describes in detail the specific product structure and working principle of the micron bubble generator (i.e., bubble breaker). The application document states that "the micron bubble generator includes a main body and a secondary crushing member, a cavity is provided in the main body, an inlet connected to the cavity is provided on the main body, the first and second opposite ends of the cavity are open, wherein the cross-sectional area of ​​the cavity decreases from the middle of the cavity to the first and second ends of the cavity; the secondary crushing member is provided at at least one of the first and second ends of the cavity, a part of the secondary crushing member is provided in the cavity, and an annular channel is formed between the secondary crushing member and the through holes open at both ends of the cavity. The micron bubble generator also includes an air inlet pipe and a liquid inlet pipe." From the specific structure disclosed in the application document, it can be known that its specific working principle is: the liquid enters the micron bubble generator tangentially through the liquid inlet pipe, rotates at ultra-high speed and cuts the gas, so that the gas bubbles are broken into micron-level microbubbles, thereby increasing the mass transfer area between the liquid phase and the gas phase, and the micron bubble generator in the patent is a pneumatic bubble breaker.

[0025] In addition, the prior patent 201610641251.7 records that the primary bubble breaker has a circulating liquid inlet, a circulating gas inlet and a gas-liquid mixture outlet, and the secondary bubble breaker connects the feed port with the gas-liquid mixture outlet, indicating that the bubble breaker requires gas-liquid mixture to enter. In addition, it can be seen from the following figures that the primary bubble breaker mainly uses circulating liquid as power, so the primary bubble breaker actually belongs to a hydraulic enhanced reactor, and the secondary bubble breaker simultaneously passes the gas-liquid mixture into an elliptical rotating ball for rotation, thereby achieving bubble breaking during the rotation process, so the secondary bubble breaker actually belongs to a gas-liquid linkage type bubble breaker. In fact, whether it is a hydraulic bubble breaker or a gas-liquid linkage type bubble breaker, it is a specific form of a bubble breaker. However, the enhanced mass transfer reactor adopted by the utility model is not limited to the above-mentioned forms. The specific structure of the bubble breaker recorded in the prior patent is only one of the forms that can be adopted by the utility model.

[0026] In addition, the prior patent 201710766435.0 records that "the principle of the bubble breaker is a high-speed jet to achieve mutual collision of gases"; and the prior patent CN106187660 also has relevant records on the specific structure of the bubble breaker, see paragraphs

[0031] -

[0041] in the specification, and the drawings, which explain in detail the specific working principle of the bubble breaker S-2. The top of the bubble breaker is a liquid phase inlet, and the side is a gas phase inlet. The liquid phase coming in from the top provides suction power, thereby achieving the effect of crushing into ultrafine bubbles. It can also be seen in the drawings that the bubble breaker has a conical structure, and the diameter of the upper part is larger than that of the lower part, so that the liquid phase can better provide suction power.

[0027] Since the bubble breaker was just developed in the early stage of the prior patent application, it was named micron bubble generator (CN201610641119.6) in the early stage. With the continuous technical improvement, it was later renamed as bubble breaker. Now the enhanced mass transfer reactor in the utility model is equivalent to the previous micron bubble generator, micro interface generator, etc., but the name is different. In summary, the enhanced mass transfer reactor of the utility model belongs to the prior art.

[0028] The utility model also provides an ethylbenzene enhanced oxidation reaction method, which adopts the above-mentioned system and comprises: breaking the gaseous raw material into micro-bubbles at the micron level through enhanced mass transfer, and then mixing it with the liquid raw material for oxidation reaction; wherein the gaseous raw material is air or oxygen, and the liquid raw material is ethylbenzene.

[0029] Compared with the prior art, the beneficial effects of the utility model are:

[0030] 1. The utility model uses only one oxidation reactor, which can reduce the occupied area and help reduce production costs.

[0031] 2. The utility model sets a first enhanced mass transfer unit in the oxidation reactor, and the gaseous raw material enters the oxidation reactor after being processed by the first enhanced mass transfer unit. As a result, the gas-liquid contact area between the gaseous raw material and the liquid raw material can be increased, the gas-liquid mass transfer efficiency can be improved, and thus the reaction efficiency can be improved.

[0032] 3. The utility model can control the temperature of the material in the oxidation reactor by setting a heat exchange pipe, using the first heat exchanger to prevent the reaction temperature from fluctuating violently due to the heat release of the oxidation reaction, and maintain the stability of the reaction temperature, thereby helping to improve the conversion rate and selectivity of the reaction and increase the yield of the reaction product.

[0033] 4. In the utility model, the heat exchange pipe can play a local stirring role on the material inside the oxidation reactor during the heat exchange process of the material, which helps to evenly distribute the microbubbles output by the first enhanced mass transfer unit in the oxidation reactor and avoid bubble aggregation, thereby helping to further improve the reaction efficiency and product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used for the purpose of illustrating the preferred embodiment and are not considered to be limiting of the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0035] Figure 1 A schematic diagram showing an ethylbenzene enhanced oxidation reaction system according to an embodiment of the utility model;

[0036] Figure 2 A schematic diagram of an ethylbenzene enhanced oxidation reaction system according to another embodiment of the utility model is shown.

[0037] Among them: 1. oxidation reactor; 101. product outlet; 102. tail gas outlet; 2. grille; 3. first enhanced mass transfer unit; 4. air inlet pipe; 5. heat exchange pump; 6. heat exchange pipe; 7. first heat exchanger; 8. circulation pipe; 9. second heat exchanger; 10. circulation pump; 11. liquid inlet pipe; 12. baffle; 13. second enhanced mass transfer unit; 14. protrusion. DETAILED DESCRIPTION

[0038] The technical solution of the utility model will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but those skilled in the art will understand that the embodiments described below are part of the embodiments of the utility model, rather than all of the embodiments, and are only used to illustrate the utility model, and should not be considered as limiting the scope of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the utility model. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0039] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In order to more clearly explain the technical solution of the present invention, it is described in the form of specific embodiments below.

[0042] Example 1

[0043] Figure 1 A schematic diagram of an ethylbenzene enhanced oxidation reaction system according to an embodiment of the present invention is shown. Figure 1 As shown, the ethylbenzene enhanced oxidation reaction system includes: an oxidation reactor 1, the oxidation reactor 1 is connected to an air inlet pipe 4 for inputting a gas phase raw material and a liquid inlet pipe 11 for inputting a liquid phase raw material; a product outlet 101 is arranged on the side wall of the oxidation reactor 1; a first enhanced mass transfer unit 3, the first enhanced mass transfer unit 3 is arranged inside the oxidation reactor 1, the air inlet pipe 4 is connected to the first enhanced mass transfer unit 3, and the gas phase raw material in the air inlet pipe 4 enters the oxidation reactor 1 after being processed by the first enhanced mass transfer unit 3, so as to enhance the mass transfer effect between the gas phase raw material and the liquid phase raw material; a heat exchange pipe 6, the inlet and outlet of the heat exchange pipe 6 are both connected to the oxidation reactor 1, and the inlet of the heat exchange pipe 6 is arranged below the outlet of the heat exchange pipe 6 in the vertical direction; a first heat exchanger 7 is arranged on the heat exchange pipe 6.

[0044] In the embodiment of the present invention, the liquid phase raw material is ethylbenzene, and the gas phase raw material can be air or oxygen. The reactor can be a bubble column reactor.

[0045] In the embodiment of the utility model, a first enhanced mass transfer unit 3 is provided inside the oxidation reactor 1. Optionally, the enhanced mass transfer unit can be composed of one or more enhanced mass transfer reactors. When the oxidation reactor 1 is working, the gaseous raw material can be dispersed and broken into micro-bubbles of micron level by the first enhanced mass transfer unit to increase the phase boundary mass transfer area between the gaseous raw material and the liquid raw material, thereby enhancing the mass transfer effect between the gaseous raw material and the liquid raw material. Figure 1 In the illustrated embodiment, the first intensified mass transfer unit 3 comprises an intensified mass transfer reactor.

[0046] Optionally, a heat exchange pump 5 may be provided on the heat exchange pipe 6. Figure 1 In the illustrated embodiment, the heat exchange pump 5 may be arranged in front of the first heat exchanger along the material flow direction in the heat exchange pipe 6 , thereby reducing the operating resistance of the heat exchange pump 5 .

[0047] Preferably, if Figure 1 As shown, the ethylbenzene enhanced oxidation reaction system also includes a circulation pipeline 8; the inlet of the circulation pipeline 8 is connected to the bottom of the oxidation reactor 1; the outlet of the circulation pipeline 8 is connected to the oxidation reactor 1, the outlet of the circulation pipeline 8 is higher than the inlet of the circulation pipeline 8 in the vertical direction and the outlet of the circulation pipeline 8 is lower than the liquid level of the oxidation reactor 1 in the vertical direction; the liquid inlet pipeline 11 is connected to the circulation pipeline 8, and the liquid raw material in the liquid inlet pipeline 11 enters the oxidation reactor 1 through the circulation pipeline 8; a second enhanced mass transfer unit 13 is arranged in the circulation pipeline 8 near the outlet of the circulation pipeline 8, and the second enhanced mass transfer unit 13 is connected to the air inlet pipeline 4, and the gaseous raw material in the air inlet pipeline 4 enters the circulation pipeline 8 after being processed by the second enhanced mass transfer unit 13, so as to enhance the mass transfer effect between the gaseous raw material and the liquid raw material; the product outlet 101 is higher than the outlet of the circulation pipeline 8 in the vertical direction, and the product outlet 101 is located below the liquid level of the oxidation reactor 1 in the vertical direction. Figure 1 In the illustrated embodiment, the second intensified mass transfer unit 13 comprises an intensified mass transfer reactor.

[0048] It can be understood that the air intake pipe 4 connected to the first enhanced mass transfer unit 3 and the air intake pipe 4 connected to the second enhanced mass transfer unit 13 can be the same air intake pipe. In this case, the air intake pipe 4 can be provided with a plurality of branch pipes to be respectively connected to different enhanced mass transfer units. Of course, the air intake pipe 4 connected to the first enhanced mass transfer unit 3 and the air intake pipe 4 connected to the second enhanced mass transfer unit 13 can also be independent air intake pipes, which will not be described in detail.

[0049] Preferably, if Figure 1As shown, a baffle 12 is provided in the oxidation reactor 1, the top of the baffle 12 is higher than the liquid level of the oxidation reactor 1 in the vertical direction, and the distance between the bottom of the baffle 12 and the bottom of the inner cavity of the oxidation reactor 1 is a preset distance; a circulation channel is formed between the baffle 12 and the side wall of the oxidation reactor 1, and the outlet of the circulation pipe 8 is connected to the circulation channel. The preset distance can be set according to actual needs, so that the material in the circulation channel flows out between the bottom of the baffle 12 and the bottom of the inner cavity of the oxidation reactor 1.

[0050] Preferably, if Figure 1 As shown, the distance between the second enhanced mass transfer unit 13 and the inner wall of the oxidation reactor 1 is smaller than the distance between the baffle 12 and the inner wall of the oxidation reactor 1 , and the distance between the baffle 12 and the inner wall of the oxidation reactor 1 is smaller than the distance between the baffle 12 and the first enhanced mass transfer unit 3 .

[0051] Preferably, if Figure 1 As shown, the second enhanced mass transfer unit 13 is arranged at the outlet of the circulation pipeline.

[0052] Preferably, if Figure 1 As shown, a plurality of protrusions 14 are sequentially arranged from top to bottom on one side of the baffle 12 close to the side wall of the oxidation reactor 1 .

[0053] Preferably, if Figure 1 As shown, a second heat exchanger 9 is provided on the circulation pipeline 8 , and the material in the circulation pipeline 8 is circulated to the oxidation reactor 1 after heat exchange in the second heat exchanger 9 .

[0054] Preferably, if Figure 1 As shown, a circulation pump 10 is provided on the circulation pipeline 8 , and the circulation pump 10 is located in front of the second heat exchanger 9 along the liquid flow direction in the circulation pipeline 8 .

[0055] Preferably, if Figure 1 As shown, there are multiple first intensified mass transfer units 3, and the multiple first intensified mass transfer units 3 are all lower than the product outlet 101 in the vertical direction.

[0056] Preferably, if Figure 1 As shown, a plurality of first enhanced mass transfer units 3 are arranged in sequence from top to bottom along the vertical direction.

[0057] Preferably, if Figure 1 As shown, the outlets of the plurality of first intensified mass transfer units 3 face downward.

[0058] Preferably, see Figure 1 The number of heat exchange pipes 6 is multiple, and the multiple heat exchange pipes 6 are arranged in sequence from top to bottom. The number of heat exchange pipes 6 can be selected according to the height of the oxidation reactor 1, which will not be described in detail. Figure 1 In the illustrated embodiment, the number of the heat exchange pipes 6 is two.

[0059] Preferably, see Figure 1 A plurality of layers of grilles 2 are staggered from top to bottom in the oxidation reactor 1 , and the plurality of layers of grilles 2 are located below the liquid surface of the oxidation reactor 1 .

[0060] This embodiment also provides an ethylbenzene enhanced oxidation reaction method, which adopts the above-mentioned ethylbenzene enhanced oxidation reaction system, and the method includes: breaking the gas phase raw material into micro-bubbles of micron level through enhanced mass transfer, and then mixing it with the liquid phase raw material for oxidation reaction; wherein the gas phase raw material is air or oxygen, and the liquid phase raw material is ethylbenzene. The reaction product can be extracted from the product outlet 101, and the tail gas in the reaction process is discharged through the tail gas outlet 102.

[0061] Example 2

[0062] The difference between this embodiment and embodiment 1 is that the circulation pipeline 8 is not provided in this embodiment, the second enhanced mass transfer unit 13 is provided in the circulation channel, and the liquid inlet pipeline 11 is directly connected to the circulation channel.

[0063] Example 3

[0064] The only difference between this embodiment and embodiment 1 is that the second enhanced mass transfer unit 13 is not provided in this embodiment.

[0065] Example 4

[0066] The only difference between this embodiment and Embodiment 1 is that the baffle 12 is not provided in this embodiment.

[0067] Example 5

[0068] The only difference between this embodiment and embodiment 1 is that the second heat exchanger 9 is not provided in this embodiment.

[0069] Example 6

[0070] The difference between this embodiment and embodiment 1 is that in this embodiment, a plurality of first enhanced mass transfer units 3 are arranged in sequence along the horizontal direction.

[0071] Example 7

[0072] The difference between this embodiment and the first embodiment is that the grille 2 is not provided in this embodiment.

[0073] Example 8

[0074] The only difference between this embodiment and Embodiment 1 is that in this embodiment, a plurality of heat exchange pipes 6 are arranged in sequence along the horizontal direction.

[0075] Example 9

[0076] The only difference between this embodiment and embodiment 1 is that in this embodiment, the distance between the baffle and the inner wall of the oxidation reactor is greater than the distance between the baffle and the first enhanced mass transfer unit.

[0077] Example 10

[0078] The only difference between this embodiment and embodiment 1 is that in this embodiment, the distance between the baffle and the inner wall of the oxidation reactor is greater than the distance between the second enhanced mass transfer unit and the inner wall of the oxidation reactor.

[0079] Embodiment 11

[0080] Figure 2 A schematic diagram of an ethylbenzene enhanced oxidation reaction system according to another embodiment of the present invention is shown. Figure 2 As shown, the ethylbenzene enhanced oxidation reaction system includes: an oxidation reactor 1, the oxidation reactor 1 is connected to an air inlet pipe 4 for inputting a gas phase raw material and a liquid inlet pipe 11 for inputting a liquid phase raw material; a product outlet 101 is arranged on the side wall of the oxidation reactor 1; a first enhanced mass transfer unit 3, the first enhanced mass transfer unit 3 is arranged inside the oxidation reactor 1, the air inlet pipe 4 is connected to the first enhanced mass transfer unit 3, and the gas phase raw material in the air inlet pipe 4 enters the oxidation reactor 1 after being processed by the first enhanced mass transfer unit 3, so as to enhance the mass transfer effect between the gas phase raw material and the liquid phase raw material; a heat exchange pipe 6, the inlet and outlet of the heat exchange pipe 6 are both connected to the oxidation reactor 1, and the inlet of the heat exchange pipe 6 is arranged below the outlet of the heat exchange pipe 6 in the vertical direction; a first heat exchanger 7 is arranged on the heat exchange pipe 6.

[0081] In the embodiment of the present invention, the liquid phase raw material is ethylbenzene, and the gas phase raw material can be air or oxygen. The reactor can be a bubble column reactor.

[0082] In the embodiment of the utility model, a first enhanced mass transfer unit 3 is provided inside the oxidation reactor 1. Optionally, the enhanced mass transfer unit can be composed of one or more enhanced mass transfer reactors. When the reactor is working, the gaseous raw material can be dispersed and broken into micro-bubbles of micron level by the enhanced mass transfer unit to increase the phase boundary mass transfer area between the gaseous raw material and the liquid raw material, thereby enhancing the mass transfer effect between the gaseous raw material and the liquid raw material. Figure 2 In the illustrated embodiment, the first intensified mass transfer unit 3 comprises an intensified mass transfer reactor.

[0083] Optionally, a heat exchange pump 5 may be provided on the heat exchange pipe 6. Figure 2 In the illustrated embodiment, the heat exchange pump 5 may be arranged in front of the first heat exchanger along the material flow direction in the heat exchange pipe 6 , thereby reducing the operating resistance of the heat exchange pump 5 .

[0084] Preferably, if Figure 2As shown, the product outlet 101 is arranged at the lower part of the oxidation reactor 1, the liquid inlet pipe 11 is connected to the upper part of the oxidation reactor 1, and the liquid inlet pipe 11 is lower than the liquid level of the oxidation reactor 1 in the vertical direction; there are multiple first enhanced mass transfer units 3, and the multiple first enhanced mass transfer units 3 are sequentially arranged between the liquid inlet pipe 11 and the product outlet 101 in the vertical direction.

[0085] Preferably, if Figure 2 As shown, the outlets of the plurality of first intensified mass transfer units 3 face upward.

[0086] Preferably, if Figure 2 As shown, there are multiple heat exchange pipes 6, and the multiple heat exchange pipes 6 are arranged in sequence from top to bottom. Figure 2 In the illustrated embodiment, the number of the heat exchange pipes 6 is two.

[0087] Preferably, if Figure 2 As shown, multiple layers of grilles 2 are alternately arranged from top to bottom in the oxidation reactor 1 , and the multiple layers of grilles 2 are located below the liquid surface of the oxidation reactor 1 .

[0088] This embodiment also provides an ethylbenzene enhanced oxidation reaction method, which adopts the above-mentioned ethylbenzene enhanced oxidation reaction system, and the method includes: breaking the gas phase raw material into micro-bubbles of micron level through enhanced mass transfer, and then mixing it with the liquid phase raw material for oxidation reaction; wherein the gas phase raw material is air or oxygen, and the liquid phase raw material is ethylbenzene. The reaction product can be extracted from the product outlet 101, and the tail gas in the reaction process is discharged through the tail gas outlet 102.

[0089] Example 12

[0090] The only difference between this embodiment and embodiment 11 is that in this embodiment, a plurality of first enhanced mass transfer units 3 are arranged in sequence along the horizontal direction.

[0091] Embodiment 13

[0092] The only difference between this embodiment and embodiment 11 is that the grille 2 is not provided in this embodiment.

[0093] Embodiment 14

[0094] The only difference between this embodiment and embodiment 11 is that in this embodiment, a plurality of heat exchange pipes 6 are arranged in sequence along the horizontal direction.

[0095] Comparative Example 1

[0096] The only difference between this embodiment and embodiment 1 is that the first enhanced mass transfer unit 3 is not provided.

[0097] Comparative Example 2

[0098] The only difference between this embodiment and Embodiment 1 is that the first heat exchanger 7 is not provided.

[0099] Comparative Example 3

[0100] The only difference between this embodiment and embodiment 1 is that the heat exchange pipe 6 is not provided.

[0101] Comparative Example 4

[0102] The only difference between this embodiment and embodiment 11 is that the first enhanced mass transfer unit 3 is not provided.

[0103] Comparative Example 5

[0104] The only difference between this embodiment and Embodiment 11 is that the first heat exchanger 7 is not provided.

[0105] Comparative Example 6

[0106] The only difference between this embodiment and embodiment 11 is that the heat exchange pipe 6 is not provided.

[0107] Comparative Example 7

[0108] In this embodiment, two non-catalytic, liquid-phase oxidation reactors connected in series are used as reactors for the ethylbenzene peroxidation reaction.

[0109] Experimental example

[0110] Ethylbenzene hydrogen peroxide was prepared by the ethylbenzene enhanced oxidation systems of Examples 1-14 and Comparative Examples 1-7, respectively. The gas phase raw material was air, the liquid phase raw material was ethylbenzene, the reaction temperature in the oxidation reactor was 145° C., and the pressure was 0.24 MPa. The concentration of ethylbenzene hydrogen peroxide in the product of each ethylbenzene enhanced oxidation system was detected, and the detection results are shown in Table 1.

[0111] Table 1 Concentration of ethylbenzene hydroperoxide in the product

[0112]

[0113]

[0114] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained by Example 1 with the concentration of ethylbenzene hydroperoxide in the product obtained by Example 2, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 1 is significantly higher than that of Example 2. This is because Example 1 can stir the materials in the oxidation reactor by setting a circulation pipeline, thereby improving the uniformity of the distribution of microbubbles in the materials inside the oxidation reactor, and the microbubbles output by the second enhanced mass transfer unit can flow back to the oxidation reactor with the circulating materials under the impact of the materials in the circulation pipeline, and the microbubbles can be further dispersed and broken under this impact, and the microbubbles can be more evenly distributed in the circulating materials under the impact of the materials, avoiding the occurrence of bubble aggregation, thereby helping to further improve the gas-liquid contact area, thereby helping to further improve the reaction efficiency and reaction yield. In short, the scheme of Example 1 helps to improve the concentration of ethylbenzene hydroperoxide in the product by combining the circulation pipeline with the second enhanced mass transfer unit.

[0115] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 1 with the concentration of ethylbenzene hydroperoxide in the product obtained in Example 3, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 1 is higher than that in Example 3. This may be because in the scheme of Example 1, a second enhanced mass transfer unit is set in the circulation pipeline, and the second enhanced mass transfer unit is used to enhance the dispersion and crushing effect of the gas phase raw material, thereby further increasing the concentration of ethylbenzene hydroperoxide in the product.

[0116] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 1 with the concentration of ethylbenzene hydroperoxide in the product obtained in Example 4, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 1 is higher than that in Example 4. This may be because the material circulating back to the oxidation reactor in the circulation pipeline in Example 4 impacts the reaction product in the oxidation reactor, causing the reaction product to be back-mixed, thereby inhibiting the occurrence of ethylbenzene peroxidation. As a result, the concentration of ethylbenzene hydroperoxide in the reaction product of the ethylbenzene peroxidation reaction is relatively low.

[0117] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 1 with the concentration of ethylbenzene hydroperoxide in the product obtained in Example 5, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 1 is higher than that in Example 5. This may be because a second heat exchanger is provided on the circulation pipeline of Example 1, which can better control the reaction temperature, making the reaction temperature in the oxidation reactor more stable, and thus the concentration of ethylbenzene hydroperoxide in the obtained product is higher.

[0118] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 1 with the concentration of ethylbenzene hydroperoxide in the product obtained in Example 6, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 1 is higher than that in Example 6. This may be because the microbubbles output by the horizontally arranged multiple first enhanced mass transfer units are all at the same height section of the oxidation reactor, causing the bubbles to coalesce, affecting the reaction efficiency and yield. As a result, the concentration of ethylbenzene hydroperoxide in the reaction product of the ethylbenzene peroxidation reaction in Example 6 is relatively low.

[0119] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 1 with the concentration of ethylbenzene hydroperoxide in the product obtained in Example 7, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 1 is higher than that in Example 7. This may be because in Example 1, by providing a barrier, liquid phase backmixing is further avoided, thereby ensuring the orderly progress of the ethylbenzene peroxidation reaction, and thus the concentration of ethylbenzene hydroperoxide in the obtained product is higher.

[0120] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 1 with the concentration of ethylbenzene hydroperoxide in the product obtained in Example 8, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 1 is higher than that in Example 8. This may be because in Example 1, multiple heat exchange pipes are respectively arranged at different heights, which has a better control effect on the temperature in the oxidation reactor, so the concentration of ethylbenzene hydroperoxide in the obtained product is higher.

[0121] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 1 with the concentration of ethylbenzene hydroperoxide in the product obtained in Example 9, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 1 is higher than that in Example 9. This may be because the distance between the baffle and the inner wall of the oxidation reactor in Example 9 is greater than the distance between the baffle and the first enhanced mass transfer unit. At this time, the width of the circulation channel is large, and the internal material flow rate is relatively slow. At this time, the microbubbles with inconsistent scales in the first microbubble flow may have bubble aggregation inside, generating microbubbles with larger scales. When these microbubbles flow to the vicinity of the first enhanced mass transfer unit, the microbubbles near the first enhanced mass transfer unit are unevenly distributed, affecting the reaction efficiency. At the same time, since the distance between the baffle and the first enhanced mass transfer unit is relatively close at this time, the first microbubble flow with uneven scales and containing larger microbubbles flowing out of the circulation channel directly flows to the vicinity of the first enhanced mass transfer unit, and may directly collide with the microbubble flow output by the first enhanced mass transfer unit, and gather and generate larger microbubbles, which further aggravates the uneven distribution of microbubbles near the first enhanced mass transfer unit. Based on the above reasons, the concentration of ethylbenzene hydroperoxide in the reaction product in the oxidation reactor in Example 9 is lower than that in Example 1.

[0122] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 1 with the concentration of ethylbenzene hydroperoxide in the product obtained in Example 10, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 1 is higher than that in Example 10. This may be because the distance between the baffle and the inner wall of the oxidation reactor in Example 10 is greater than the distance between the second enhanced mass transfer unit and the inner wall of the oxidation reactor. At this time, bubbles may have coalesced during the flow of the first microbubble flow in the circulation pipeline, generating larger microbubbles, thereby increasing the scale difference between the microbubbles in the first microbubble flow and the microbubbles output by the first enhanced mass transfer unit, resulting in uneven distribution of microbubbles near the first enhanced mass transfer unit, affecting the reaction efficiency. As a result, the concentration of ethylbenzene hydroperoxide in the reaction product in the oxidation reactor in Example 10 is lower than that in Example 1.

[0123] Combining the data of Example 1, Example 9 and Example 10, it can be seen that the solution of Example 1 of the utility model effectively improves the reaction efficiency of ethylbenzene peroxidation reaction by specifically setting the relative position relationship between the first enhanced mass transfer unit, the baffle and the second enhanced mass transfer unit.

[0124] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 1 with the concentration of ethylbenzene hydroperoxide in the product obtained in Comparative Example 1, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 1 is significantly higher than that of Comparative Example 1. This may be because Example 1 can increase the gas-liquid contact area by setting multiple first enhanced mass transfer units, and the air inlet pipeline can supplement the gas phase raw material to different height sections of the oxidation reactor through multiple first enhanced mass transfer units, ensuring that the gas phase raw material is always in excess, thereby improving the reaction yield and raw material conversion rate.

[0125] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 1 with the concentration of ethylbenzene hydroperoxide in the product obtained in Comparative Example 2, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 1 is significantly higher than that in Comparative Example 2. This may be because in Example 1, by providing the first heat exchanger, the temperature in the oxidation reactor can be more accurately controlled, making the temperature in the oxidation reactor more stable, and thus the concentration of ethylbenzene hydroperoxide in the obtained product is higher.

[0126] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 1 with the concentration of ethylbenzene hydroperoxide in the product obtained in Comparative Example 3, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 1 is significantly higher than that in Comparative Example 3. This may be because Example 1, by providing a heat exchange pipe, can stir the material on the one hand, thereby improving the uniformity of the distribution of microbubbles in the oxidation reactor, and on the other hand, the heat exchange pipe can maintain the reaction temperature in the oxidation reactor through the first heat exchanger to make the reaction more orderly. Therefore, the concentration of ethylbenzene hydroperoxide in the obtained product is higher.

[0127] Comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 11 with the concentration of ethylbenzene hydroperoxide in the product obtained in Example 12, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 11 is significantly higher than that in Example 12. This may be because the microbubbles output by the multiple horizontally arranged first enhanced mass transfer units are all at the same height section of the oxidation reactor, causing the bubbles to coalesce, affecting the reaction efficiency and yield.

[0128] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 11 with the concentration of ethylbenzene hydroperoxide in the product obtained in Example 13, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 11 is significantly higher than that in Example 13. This may be because in Example 11, by providing a barrier, liquid phase backmixing is further avoided, thereby ensuring the orderly progress of the ethylbenzene peroxidation reaction, and therefore the concentration of ethylbenzene hydroperoxide in the obtained product is higher.

[0129] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 11 with the concentration of ethylbenzene hydroperoxide in the product obtained in Example 14, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 11 is significantly higher than that in Example 14. This may be because in Example 11, multiple heat exchange pipes are respectively arranged at different heights, which has a better control effect on the temperature in the oxidation reactor, so the concentration of ethylbenzene hydroperoxide in the obtained product is higher.

[0130] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 11 with the concentration of ethylbenzene hydroperoxide in the product obtained in Comparative Example 4, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 11 is significantly higher than that in Comparative Example 4, and the concentration of ethylbenzene hydroperoxide in the product of Example 11 is close to 2.7 times that of Comparative Example 4. This may be because Example 11 can increase the gas-liquid contact area by providing multiple first enhanced mass transfer units, and the air inlet pipeline can supplement the gas phase raw material to different height sections of the oxidation reactor through multiple first enhanced mass transfer units, ensuring that the gas phase raw material is always in excess, thereby improving the reaction yield and raw material conversion rate.

[0131] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 11 with the concentration of ethylbenzene hydroperoxide in the product obtained in Comparative Example 5, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 11 is significantly higher than that in Comparative Example 5, and the concentration of ethylbenzene hydroperoxide in the product of Example 11 is close to 1.7 times that of Comparative Example 5. This may be because in Example 11, by providing the first heat exchanger, the temperature in the oxidation reactor can be more accurately controlled, making the temperature in the oxidation reactor more stable, and thus the concentration of ethylbenzene hydroperoxide in the obtained product is higher.

[0132] By comparing the concentration of ethylbenzene hydroperoxide in the product obtained in Example 11 with the concentration of ethylbenzene hydroperoxide in the product obtained in Comparative Example 6, it can be seen that the concentration of ethylbenzene hydroperoxide in the product of Example 11 is significantly higher than that in Comparative Example 6, and the concentration of ethylbenzene hydroperoxide in the product of Comparative Example 6 is only half of that in Example 11. This may be because Example 11 can stir the material by setting a heat exchange pipe, thereby improving the uniformity of the distribution of microbubbles in the oxidation reactor, and on the other hand, the heat exchange pipe can maintain the reaction temperature in the oxidation reactor through the first heat exchanger to make the reaction more orderly. Therefore, the concentration of ethylbenzene hydroperoxide in the product obtained is significantly improved compared with Comparative Example 6.

[0133] Comparative Example 7 is a solution adopted in the related art. By comparing Examples 1-14 with Comparative Example 7, it can be seen that the concentration of ethylbenzene hydroperoxide in the reaction products in Examples 1-14 is significantly higher than that in Comparative Example 7. This shows that the ethylbenzene enhanced oxidation reaction system of the utility model can significantly improve the reaction efficiency and product yield of the ethylbenzene peroxidation reaction, and the concentration of ethylbenzene hydroperoxide in Examples 1-14 basically meets the requirements of the downstream epoxidation reaction (i.e., the concentration of ethylbenzene hydroperoxide in the product reaches about 40wt%). Therefore, when the system of the utility model is applied to the PO / SM co-production process, there is no need to set a concentration unit to further concentrate the product, and the reaction product of the reactor can be directly sent to the epoxidation reactor, which can reduce the occupied area of ​​the production system adopted by the PO / SM co-production process and reduce the production cost.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. An ethylbenzene enhanced oxidation reaction system, characterized in that: include: An oxidation reactor, wherein the oxidation reactor is connected to an air inlet pipeline for inputting gaseous raw materials and a liquid inlet pipeline for inputting liquid raw materials; a product outlet is arranged on a side wall of the oxidation reactor; a first enhanced mass transfer unit, wherein the first enhanced mass transfer unit is arranged inside the oxidation reactor, the air inlet pipeline is connected to the first enhanced mass transfer unit, and the gaseous raw material in the air inlet pipeline enters the oxidation reactor after being processed by the first enhanced mass transfer unit, so as to enhance the mass transfer effect between the gaseous raw material and the liquid raw material; A heat exchange pipe, the inlet and outlet of the heat exchange pipe are both connected to the oxidation reactor, and the inlet of the heat exchange pipe is arranged below the outlet of the heat exchange pipe in the vertical direction; a first heat exchanger is arranged on the heat exchange pipe.

2. The ethylbenzene enhanced oxidation reaction system according to claim 1, characterized in that: It also includes a circulation pipeline; the inlet of the circulation pipeline is connected to the bottom of the oxidation reactor; the outlet of the circulation pipeline is connected to the oxidation reactor, the outlet of the circulation pipeline is higher than the inlet of the circulation pipeline in the vertical direction and the outlet of the circulation pipeline is lower than the liquid level of the oxidation reactor in the vertical direction; The liquid inlet pipeline is in communication with the circulation pipeline, and the liquid raw material in the liquid inlet pipeline enters the oxidation reactor through the circulation pipeline; A second enhanced mass transfer unit is arranged in the circulation pipeline near the outlet of the circulation pipeline, and the second enhanced mass transfer unit is connected to the air inlet pipeline. The gaseous raw material in the air inlet pipeline enters the circulation pipeline after being processed by the second enhanced mass transfer unit, so as to enhance the mass transfer effect between the gaseous raw material and the liquid raw material; The product outlet is higher than the outlet of the circulation pipeline in the vertical direction, and the product outlet is located below the liquid surface of the oxidation reactor in the vertical direction.

3. The ethylbenzene enhanced oxidation reaction system according to claim 2, characterized in that: A baffle is arranged in the oxidation reactor, the top of the baffle is higher than the liquid level of the oxidation reactor in the vertical direction, and the distance between the bottom of the baffle and the bottom of the inner cavity of the oxidation reactor is a preset distance; a circulation channel is formed between the baffle and the side wall of the oxidation reactor, and the outlet of the circulation pipe is connected to the circulation channel.

4. The ethylbenzene enhanced oxidation reaction system according to claim 3, characterized in that: The distance between the second enhanced mass transfer unit and the inner wall of the oxidation reactor is smaller than the distance between the baffle and the inner wall of the oxidation reactor, and the distance between the baffle and the inner wall of the oxidation reactor is smaller than the distance between the baffle and the first enhanced mass transfer unit.

5. The ethylbenzene enhanced oxidation reaction system according to claim 2, characterized in that: There are multiple first intensified mass transfer units, and the multiple first intensified mass transfer units are all lower than the product outlet in the vertical direction.

6. The ethylbenzene enhanced oxidation reaction system according to claim 2, characterized in that: The circulation pipeline is provided with a second heat exchanger, and the material in the circulation pipeline is circulated to the oxidation reactor after heat exchange in the second heat exchanger.

7. The ethylbenzene enhanced oxidation reaction system according to claim 1, characterized in that: The product outlet is arranged at the lower part of the oxidation reactor, the liquid inlet pipeline is communicated with the upper part of the oxidation reactor and the liquid inlet pipeline is lower than the liquid level of the oxidation reactor in the vertical direction.

8. The ethylbenzene enhanced oxidation reaction system according to claim 7, characterized in that: There are multiple first intensified mass transfer units, and the multiple first intensified mass transfer units are sequentially arranged between the liquid inlet pipeline and the product outlet along the vertical direction.

9. The ethylbenzene enhanced oxidation reaction system according to any one of claims 1 to 8, characterized in that: There are multiple heat exchange pipes, and the multiple heat exchange pipes are arranged in sequence from top to bottom.

10. The ethylbenzene enhanced oxidation reaction system according to any one of claims 1 to 8, characterized in that: Multiple layers of grilles are staggered from top to bottom in the oxidation reactor, and the multiple layers of grilles are located below the liquid surface of the oxidation reactor.

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