A cumene oxidation reaction system and method

Abstract

The present invention relates to the technical field of cumene oxidation, and specifically to a cumene oxidation reaction system and method, comprising an oxidation tower and a gas-liquid separator; the oxidation tower is sequentially provided with a bubbling reactor and a microbubble generator from top to bottom; the bottom of the oxidation tower is connected to a gas supply device and a liquid supply device, respectively, and the top is connected to the gas-liquid separator; the top of the gas-liquid separator is connected to a condensing device and the gas supply device, respectively, and the condensing device is connected to an oxygen analysis device; a liquid circulation device is provided between the bottom of the gas-liquid separator and the bottom of the oxidation tower, for circulating the liquid inside the gas-liquid separator to the inside of the microbubble generator. Utilizing this system, the efficiency of cumene oxidation to produce cumene hydroperoxide can be effectively improved, and the system has the advantages of high cumene hydroperoxide production rate, high selectivity, and high safety.

Description

Technical Field

[0001] The present invention relates to the technical field of cumene oxidation, and in particular to a cumene oxidation reaction system and method. Background Art

[0002] Phenol, as an important chemical raw material, is commonly used in the preparation of chemical intermediates and various fine chemicals, such as epoxy resins, phenolic resins, polycarbonates, salicylic acid, etc. At present, more than 90% of phenol in industry is synthesized through the cumene oxidation process, with the co-production of acetone. The main production steps are as follows: (1) Benzene and propylene undergo alkylation reaction to produce cumene; (2) Cumene is oxidized by air to form cumene hydroperoxide (CHP); (3) CHP is decomposed under acidic conditions to produce equimolar amounts of phenol and acetone. Among them, the cumene oxidation process is the key step affecting the purity and yield of phenol. However, the traditional cumene oxidation process has many defects, such as slow reaction rate and low selectivity of the target product. In recent years, research on the cumene oxidation process at home and abroad has mainly focused on improving the conversion rate and selectivity. However, the reaction temperature and pressure are high, the cost is also high, and because the cumene oxidation reaction mechanism is relatively complex and is essentially a slow reaction process, the effect of improving the process conditions is also very limited.

[0003] While existing technologies employ catalysts, while these can significantly improve oxidation efficiency, they also complicate the process and present numerous challenges in catalyst separation and reuse. Furthermore, non-catalytic oxidation is widely used in industrial applications, but it suffers from a slow initial reaction rate, a long induction period, and low selectivity and formation rate for the target product, CHP, making it unsuitable for large-scale production.

[0004] Patent publication number CN106588734A discloses a method and apparatus for producing cumene hydroperoxide by oxidizing cumene. Specifically, cumene and an initiator are introduced into a microreactor array consisting of one or more microreactors connected in series. A continuous flow oxidation reaction is then performed recursively until the reaction product flows into the final microreactor for oxidation, followed by flash distillation and purification. During each oxidation reaction, oxygen is introduced into all microreactors, and the molar ratio of cumene introduced into the first microreactor to the total oxygen introduced into all microreactors is 0.1:5. This solution addresses the issues of large reaction temperature fluctuations, low production efficiency, and low yield associated with traditional processes. However, microreactor technology is a forward-looking technology and currently faces significant challenges in industrial implementation.

[0005] Therefore, there is an urgent need for a cumene oxidation reaction system and method. Summary of the Invention

[0006] The present invention provides a cumene oxidation reaction system and method to solve the problems of low efficiency of cumene oxidation to cumene hydroperoxide and low selectivity of target product CHP in conventional cumene oxidation reaction equipment in the prior art.

[0007] In order to achieve the above-mentioned object, the present invention provides a cumene oxidation reaction system in a first aspect, the system comprising an oxidation tower and a gas-liquid separator;

[0008] The interior of the oxidation tower is sequentially provided with a bubbling reactor and a microbubble generator from top to bottom. The bottom of the oxidation tower is respectively connected to the gas supply equipment and the liquid supply equipment, and the top is connected to the gas-liquid separator. The top of the gas-liquid separator is respectively connected to the condensation equipment and the gas supply equipment. The condensation equipment is connected to an oxygen analysis device. A liquid circulation device is provided between the bottom of the gas-liquid separator and the bottom of the oxidation tower, for circulating the liquid inside the gas-liquid separator to the interior of the microbubble generator.

[0009] Preferably, the microbubble generator is a ceramic membrane microbubble generator.

[0010] Preferably, the average pore size of the ceramic membrane of the ceramic membrane microbubble generator is 10 nm to 10 μm, the porosity is 30 to 35%, and the transmembrane pressure difference is 0.2 to 0.5 MPa.

[0011] Preferably, the oxidation tower further comprises a first heating device for maintaining the temperature inside the oxidation tower at 90-130° C. during the cumene oxidation reaction.

[0012] Preferably, the gas-liquid separator further comprises a second heating device for maintaining the temperature inside the gas-liquid separator at 90-130° C. during the cumene oxidation reaction.

[0013] Preferably, the condensation equipment includes a condensation tank and a circulation cooler provided on the condensation tank, and the circulation cooler is used to maintain the temperature inside the condensation tank at 20-40°C.

[0014] Preferably, the bottom of the condensation tank is connected to the top of the gas-liquid separator, and the top is connected to the oxygen analysis equipment. The interior of the condensation tank is provided with a metal wire mesh corrugated packing.

[0015] Preferably, the system further comprises a reaction pressure control device for maintaining the gauge pressure inside the oxidation tower at 0-0.4 MPa during the cumene oxidation reaction.

[0016] Preferably, the circulating the liquid in the gas-liquid separator to the interior of the microbubble generator specifically includes:

[0017] During the cumene oxidation reaction, the liquid inside the gas-liquid separator is circulated and transported to the inside of the microbubble generator at a rate of 0-20 L / min, and the liquid level inside the gas-liquid separator is maintained at 30-65%.

[0018] Preferably, the gas supply device is used to deliver protective gas and / or reaction gas to the interior of the microbubble generator, and to deliver protective gas to the top of the gas-liquid separator.

[0019] Preferably, the gas supply device is used to introduce reaction gas into the interior of the microbubble generator at a rate of 0-5 L / min during the cumene oxidation reaction.

[0020] Preferably, the protective gas is an inert gas, and the reactive gas is air.

[0021] Preferably, a preheater is provided between the gas supply equipment and the oxidation tower.

[0022] Preferably, the liquid supply device is used to introduce a reaction liquid into the interior of the microbubble generator, and the reaction liquid is a cumene mixed liquid containing 0-15% cumene hydroperoxide.

[0023] A second aspect of the present invention provides a cumene oxidation reaction method, which is implemented using the above-mentioned cumene oxidation reaction system, and the method comprises the following steps:

[0024] S1, the liquid supply device transports the reaction liquid into the oxidation tower, and when the interior of the oxidation tower is filled with the reaction liquid and the liquid level of the reaction liquid in the gas-liquid separator reaches 20-30%, the reaction liquid is stopped from being transported into the oxidation tower;

[0025] S2, the liquid circulation device circulates the liquid inside the gas-liquid separator to the oxidation tower, and maintains the liquid level inside the gas-liquid separator at 20-60%;

[0026] S3, passing the protective gas preheated to 80-90° C. by the preheater into the oxidation tower, the first heating device maintains the temperature inside the oxidation tower at 80-90° C., the second heating device maintains the temperature inside the gas-liquid separator at 80-90° C., and the circulating cooler maintains the temperature inside the condensation tank at 20-40° C.;

[0027] S4, after the bubble flow in the oxidation tower is stable, the temperature inside the oxidation tower and the temperature inside the gas-liquid separator are both stable at 80-90° C., and the liquid level inside the gas-liquid separator is stable at 20-60%, raising the temperature inside the oxidation tower and the temperature inside the gas-liquid separator to 90-130° C.;

[0028] S5. The reaction pressure control device is used to maintain the gauge pressure inside the oxidation tower at 0-0.4 MPa; the reaction gas preheated to 80-90° C. in the preheater is introduced into the oxidation tower at a rate of 0-5 L / min, and the feed rate of the protective gas is gradually reduced to zero. At the same time, the liquid inside the gas-liquid separator is circulated into the oxidation tower at a rate of 0-20 L / min, and the liquid level inside the gas-liquid separator is maintained at 30-65%; wherein, during the oxidation reaction, the reading of the oxygen analysis device is controlled to always remain at 6-9.5%.

[0029] According to the above technical solution, based on the isopropylbenzene oxidation reaction system, in actual application, the isopropylbenzene is first oxidized by the oxidation tower, and then the gas and liquid are separated by the gas-liquid separator, and the isopropylbenzene component in the gas is recovered by the condensing equipment, and the liquid is circulated to the oxidation tower by the liquid circulation equipment, which can effectively improve the oxidation efficiency of the isopropylbenzene, and has the advantages of high isopropylbenzene hydroperoxide generation rate, high selectivity and high safety. Furthermore, by cooperating with the oxygen analysis equipment and the gas supply equipment, it can further effectively prevent the oxygen concentration at the top of the gas-liquid separator from being too high and from combusting and exploding with the isopropylbenzene gas component, which has the advantage of higher safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the isopropylbenzene oxidation reaction system.

[0031] Description of Reference Numerals

[0032] Oxidation tower 1; microbubble generator 11; bubbling reactor 12; first heating device 13;

[0033] Gas-liquid separator 2; second heating device 21; reaction liquid storage tank 3; preheater 4;

[0034] Condensation equipment 5; condensation tank 51; wire mesh corrugated filler 511; circulation cooler 52;

[0035] Oxygen analysis equipment 6. DETAILED DESCRIPTION

[0036] The following describes the specific implementation of the embodiment of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiment of the present invention and is not used to limit the embodiment of the present invention.

[0037] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate relative importance or implicitly specify the quantity of the technical features indicated. Therefore, unless otherwise specified, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features; "plurality" means two or more. The term "comprising" and any variations thereof are intended to imply the non-exclusive inclusion, possible presence, or addition of one or more other features, units, components, and / or combinations thereof.

[0038] Furthermore, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly, and may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0039] The first aspect of the present invention provides a cumene oxidation reaction system, such as Figure 1 As shown, the cumene oxidation reaction system includes an oxidation tower 1 and a gas-liquid separator 2;

[0040] The interior of the oxidation tower 1 is sequentially provided with a bubbling reactor 12 and a microbubble generator 11 from top to bottom. The bottom of the oxidation tower 1 is respectively connected to the gas supply equipment and the liquid supply equipment, and the top is connected to the gas-liquid separator 2. The top of the gas-liquid separator 2 is respectively connected to the condensation equipment 5 and the gas supply equipment. The condensation equipment 5 is connected to the oxygen analysis equipment 6. A liquid circulation device is provided between the bottom of the gas-liquid separator 2 and the bottom of the oxidation tower 1, which is used to circulate the liquid inside the gas-liquid separator 2 to the interior of the microbubble generator 11.

[0041] According to the above technical solution, based on the isopropylbenzene oxidation reaction system, in actual application, the isopropylbenzene is first oxidized by the oxidation tower, and then the gas and liquid are separated by the gas-liquid separator, and the isopropylbenzene component in the gas is recovered by the condensing equipment, and the liquid is circulated to the oxidation tower by the liquid circulation equipment, which can effectively improve the oxidation efficiency of the isopropylbenzene, and has the advantages of high isopropylbenzene hydroperoxide generation rate, high selectivity and high safety. Furthermore, by cooperating with the oxygen analysis equipment and the gas supply equipment, it can further effectively prevent the oxygen concentration at the top of the gas-liquid separator from being too high and from combusting and exploding with the isopropylbenzene gas component, which has the advantage of higher safety.

[0042] In the cumene oxidation reaction system of the present invention, in a preferred embodiment, the microbubble generator 11 is a ceramic membrane microbubble generator, which can effectively improve the efficiency of the cumene oxidation reaction and further improve the generation rate and selectivity of cumene hydroperoxide.

[0043] In a more preferred embodiment, the ceramic membrane of the ceramic membrane microbubble generator has an average pore size of 10 nm to 10 μm, a porosity of 30% to 35%, and a transmembrane pressure difference of 0.2 to 0.5 MPa. In practical applications, this can significantly improve the efficiency of the cumene oxidation reaction, thereby increasing the production rate and selectivity of cumene hydroperoxide.

[0044] In a preferred embodiment of the cumene oxidation reaction system of the present invention, the oxidation tower 1 further comprises a first heating device 13 for maintaining the temperature within the oxidation tower 1 at 90-130°C during the cumene oxidation reaction. Preferably, the first heating device 13 is used to maintain the temperature within the oxidation tower 1 at 90-110°C. Most preferably, the first heating device 13 is used to maintain the temperature within the oxidation tower 1 at 100°C during the cumene oxidation reaction. This effectively improves the efficiency of the cumene oxidation reaction at the temperature level and achieves optimal cumene hydroperoxide production rate and selectivity. In a specific embodiment, the first heating device 13 comprises a thermal oil generator and a hot oil pump. In actual use, the thermal oil generator is used to heat the thermal oil, which is then circulated by the hot oil pump to heat the oxidation tower 1 and stabilize it at a set temperature.

[0045] In a preferred embodiment of the cumene oxidation reaction system of the present invention, the gas-liquid separator 2 further comprises a second heating device 21 for maintaining the temperature inside the gas-liquid separator 2 at 90-130°C during the cumene oxidation reaction. Preferably, the second heating device 21 is used to maintain the temperature inside the gas-liquid separator 2 at 90-110°C during the cumene oxidation reaction. Most preferably, the second heating device 21 is used to maintain the temperature inside the gas-liquid separator 2 at 100°C during the cumene oxidation reaction. This, in conjunction with the oxidation tower 1, effectively improves the efficiency of the cumene oxidation reaction at the temperature level and achieves optimal values ​​for the cumene hydroperoxide production rate and selectivity. In a specific embodiment, the second heating device 21 is an electric heating furnace.

[0046] In a preferred embodiment of the cumene oxidation reaction system of the present invention, the condensation device 5 includes a condensation tank 51 and a circulating cooler 52 disposed on the condensation tank 51. The circulating cooler 52 maintains the temperature inside the condensation tank 51 at 20-40°C. Furthermore, a wire mesh corrugated packing 511 is disposed inside the condensation tank 51 to effectively recover the cumene component in the gas and effectively prevent explosion.

[0047] Furthermore, in a preferred embodiment, the bottom of the condensation tank 51 is connected to the top of the gas-liquid separator 2 , and the top is connected to the oxygen analysis equipment 6 .

[0048] In a preferred embodiment, the cumene oxidation reaction system of the present invention further comprises a reaction pressure control device for maintaining the gauge pressure within the oxidation tower 1 at 0-0.4 MPa during the cumene oxidation reaction. Preferably, the reaction pressure control device is used to maintain the gauge pressure within the oxidation tower 1 at 0.2-0.4 MPa during the cumene oxidation reaction. Most preferably, the gauge pressure within the oxidation tower 1 is maintained at 0.3 MPa. This further improves the cumene oxidation efficiency at the gauge pressure level within the oxidation tower 1 and achieves optimal values ​​for the cumene hydroperoxide production rate and selectivity.

[0049] In a preferred embodiment of the cumene oxidation reaction system of the present invention, the circulating of the liquid inside the gas-liquid separator 2 to the inside of the microbubble generator 11 specifically includes:

[0050] During the cumene oxidation reaction, the liquid within the gas-liquid separator 2 is circulated to the interior of the microbubble generator 11 at a rate of 0-20 L / min, and the liquid level within the gas-liquid separator 2 is maintained at 30-65%, which can effectively improve the cumene oxidation efficiency. Preferably, the liquid within the gas-liquid separator 2 is circulated to the interior of the microbubble generator 11 at a rate of 2-8 L / min, and the liquid level within the gas-liquid separator 2 is maintained at 40-60%.

[0051] In a preferred embodiment of the cumene oxidation reaction system of the present invention, the gas supply device is used to deliver protective gas and / or reaction gas to the interior of the microbubble generator 11, and to deliver protective gas to the top of the gas-liquid separator 2.

[0052] In an embodiment of the present invention, in actual application, preferably, the gas supply device is used to pass the reaction gas into the interior of the microbubble generator 11 at a rate of 0-5L / min during the oxidation reaction of isopropylbenzene. More preferably, the gas supply device is used to pass the reaction gas into the interior of the microbubble generator 11 at a rate of 2-4L / min during the oxidation reaction of isopropylbenzene, thereby further improving the oxidation efficiency of isopropylbenzene. Wherein, the gas supply device is used to deliver protective gas to the top of the gas-liquid separator 2, specifically, according to the oxygen concentration at the top of the gas-liquid separator 2 measured by the oxygen analysis device 6, the amount of protective gas passed is controlled, thereby achieving the effect of diluting the oxygen concentration, and then by maintaining the oxygen concentration at the top of the gas-liquid separator 2 below the limit oxygen concentration, thereby effectively preventing the occurrence of combustion and explosion. Specifically, the protective gas is an inert gas, preferably nitrogen, and the reaction gas is air, preferably oxygen-enriched air; the oxygen concentration in the tail gas is controlled to be 6-9.5%, preferably 6-8%; the oxygen analysis equipment 6 can be an oxygen analyzer, or other equipment with the same function.

[0053] Furthermore, in a preferred embodiment, a preheater 4 is provided between the gas supply equipment and the oxidation tower 1, so that in actual application, the oxidation efficiency of isopropylbenzene can be improved by first heating the protective gas and / or reaction gas to a preset temperature and then introducing the protective gas and / or reaction gas into the oxidation tower 1 for reaction.

[0054] In the cumene oxidation reaction system of the present invention, in a preferred embodiment, the liquid supply device is used to pass the reaction liquid into the interior of the microbubble generator 11, and the reaction liquid is a cumene mixed liquid containing 0-15% cumene hydroperoxide. Preferably, the reaction liquid is a cumene mixed liquid containing 5-10% cumene hydroperoxide. Most preferably, the reaction liquid is a cumene mixed liquid containing 8% cumene hydroperoxide. Thereby, at the level of initiator (CHP) concentration, the oxidation efficiency of cumene is further improved, and the optimal values ​​of cumene hydroperoxide generation rate and selectivity are obtained. In a specific embodiment, as Figure 1 As shown, the reaction liquid is stored in a reaction liquid storage tank 3 and transported to the oxidation tower 1 by pumping.

[0055] A second aspect of the present invention further provides a cumene oxidation reaction method, which is implemented using the above-mentioned cumene oxidation reaction system, and the method comprises the following steps:

[0056] S1, the liquid supply device transports the reaction liquid into the oxidation tower 1, and when the interior of the oxidation tower 1 is filled with the reaction liquid and the liquid level of the reaction liquid in the gas-liquid separator 2 reaches 20-30%, the reaction liquid is stopped from being transported into the oxidation tower 1;

[0057] In step S1 , preferably, when the liquid level of the reaction liquid in the gas-liquid separator 2 reaches 20%, the transportation of the reaction liquid into the oxidation tower 1 is stopped.

[0058] S2, the liquid circulation device circulates the liquid inside the gas-liquid separator 2 to the oxidation tower 1, and maintains the liquid level inside the gas-liquid separator 2 at 20-60%;

[0059] S3, the protective gas preheated to 80-90° C. by the preheater 4 is introduced into the oxidation tower 1, the first heating device 13 maintains the temperature inside the oxidation tower 1 at 80-90° C., the second heating device 21 maintains the temperature inside the gas-liquid separator 2 at 80-90° C., and the circulating cooler 52 maintains the internal temperature of the condensation tank 51 at 20-40° C.;

[0060] In step S3, preferably, the protective gas preheated to 80°C by the preheater 4 is introduced into the oxidation tower 1, so that the temperature inside the oxidation tower 1 is maintained at 80°C, the temperature inside the gas-liquid separator 2 is maintained at 80°C, and the internal temperature of the condensation tank 51 is maintained at 20°C.

[0061] S4, after the bubble flow in the oxidation tower 1 is stable, the temperature inside the oxidation tower 1 and the temperature inside the gas-liquid separator 2 are both stable at 80-90° C., and the liquid level inside the gas-liquid separator 2 is stable at 20-60%, the temperature inside the oxidation tower 1 and the temperature inside the gas-liquid separator 2 are raised to 90-130° C.;

[0062] In step S4, preferably, after the temperature inside the oxidation tower 1 and the temperature inside the gas-liquid separator 2 are both stabilized at 80°C, and the liquid level inside the gas-liquid separator 2 is stabilized at 20-60%, the temperature inside the oxidation tower 1 and the temperature inside the gas-liquid separator 2 are raised to 90-110°C.

[0063] S5. The reaction pressure control device is used to maintain the gauge pressure inside the oxidation tower 1 at 0-0.4 MPa; the reaction gas preheated to 80-90° C. by the preheater 4 is introduced into the oxidation tower 1 at a rate of 0-5 L / min, and the rate of the protective gas is gradually reduced to zero. At the same time, the liquid inside the gas-liquid separator 2 is circulated to the oxidation tower 1 at a rate of 0-20 L / min, and the liquid level of the liquid inside the gas-liquid separator 2 is maintained at 30-65%; wherein, during the oxidation reaction, the reading of the oxygen analysis device is controlled to always remain at 6-9.5%.

[0064] In step S5, preferably, the gauge pressure inside the oxidation tower 1 is maintained at 0.2-0.4 MPa, and the reaction gas preheated to 80°C by the preheater 4 is introduced into the oxidation tower 1 at a rate of 2-4 L / min; the liquid inside the gas-liquid separator 2 is circulated to the oxidation tower 1 at a rate of 2-8 L / min, and the liquid level inside the gas-liquid separator 2 is maintained at 40-60%; during the oxidation reaction, the reading of the oxygen analysis equipment is controlled to always remain at 6-8%.

[0065] The cumene oxidation reaction method of the present invention, during actual application, first oxidizes cumene through the oxidation tower, then separates gas and liquid through the gas-liquid separator, recovers the cumene component in the gas through the condensing equipment, and circulates the liquid into the oxidation tower through the liquid circulation equipment. This can effectively improve the oxidation efficiency of cumene, and has the advantages of high cumene hydroperoxide generation rate, high selectivity and high safety. Furthermore, by cooperating with the oxygen analysis equipment and the gas supply equipment, it can further effectively prevent the oxygen concentration at the top of the gas-liquid separator from being too high and from combusting and exploding with the cumene gas component, thus having the advantage of higher safety.

[0066] The present invention will be described in detail below through examples, but the protection scope of the present invention is not limited thereto.

[0067] Use Figure 1 The cumene oxidation reaction system shown is implemented, specifically, the system includes an oxidation tower 1 and a gas-liquid separator 2;

[0068] The interior of the oxidation tower 1 is sequentially provided with a bubbling reactor 12 and a microbubble generator 11 from top to bottom. The bottom of the oxidation tower 1 is respectively connected to the gas supply equipment and the liquid supply equipment, and the top is connected to the gas-liquid separator 2. The top of the gas-liquid separator 2 is respectively connected to the condensation equipment 5 and the gas supply equipment. The condensation equipment 5 is connected to the oxygen analysis equipment 6. A liquid circulation device is provided between the bottom of the gas-liquid separator 2 and the bottom of the oxidation tower 1, which is used to circulate the liquid inside the gas-liquid separator 2 to the interior of the microbubble generator 11.

[0069] Specifically, the microbubble generator 11 is a ceramic membrane microbubble generator.

[0070] The ceramic membrane of the ceramic membrane microbubble generator has an average pore size of 300 nm, a porosity of 35%, and a transmembrane pressure difference of 0.3 MPa.

[0071] The oxidation tower 1 further includes a first heating device 13 for maintaining the temperature inside the oxidation tower 1 at 90-130° C. during the cumene oxidation reaction.

[0072] The gas-liquid separator 2 further includes a second heating device 21 for maintaining the temperature inside the gas-liquid separator 2 at 90-130° C. during the cumene oxidation reaction.

[0073] The condensation device 5 includes a condensation tank 51 and a circulation cooler 52 provided on the condensation tank 51 . The circulation cooler 52 is used to maintain the temperature inside the condensation tank 51 at 20-40° C.

[0074] The bottom of the condensation tank 51 is connected to the top of the gas-liquid separator 2 , and the top is connected to the oxygen analysis equipment 6 . A wire mesh corrugated filler 511 is provided inside the condensation tank 51 .

[0075] The system also includes a reaction pressure control device for maintaining the pressure inside the oxidation tower 1 at 0-0.4 MPa during the cumene oxidation reaction.

[0076] The circulating and transporting of the liquid inside the gas-liquid separator 2 to the inside of the microbubble generator 11 specifically includes:

[0077] During the cumene oxidation reaction, the liquid in the gas-liquid separator 2 is circulated and transported to the inside of the microbubble generator 11 at a rate of 0-20 L / min, and the liquid level in the gas-liquid separator 2 is maintained at 30-65%.

[0078] The gas supply device is used to deliver protective gas and / or reaction gas to the interior of the microbubble generator 11 , and to deliver protective gas to the top of the gas-liquid separator 2 .

[0079] The gas supply device is used to introduce reaction gas into the interior of the microbubble generator 11 at a rate of 0-5 L / min during the cumene oxidation reaction.

[0080] The protective gas is nitrogen, and the reaction gas is air.

[0081] A preheater 4 is provided between the gas supply equipment and the oxidation tower 1 .

[0082] The liquid supply device is used to introduce a reaction liquid into the interior of the microbubble generator 11 , wherein the reaction liquid is a cumene mixed liquid containing 0-15% cumene hydroperoxide.

[0083] In actual application, S1, the liquid supply device transports the reaction liquid into the oxidation tower 1, and when the interior of the oxidation tower 1 is filled with the reaction liquid and the liquid level of the reaction liquid in the gas-liquid separator 2 reaches 20%, the reaction liquid is stopped from being transported into the oxidation tower 1;

[0084] S2, the liquid circulation device circulates the liquid inside the gas-liquid separator 2 into the oxidation tower 1, and maintains the liquid level inside the gas-liquid separator 2 at 50%;

[0085] S3, the protective gas preheated to 80°C by the preheater 4 is introduced into the oxidation tower 1, the first heating device 13 maintains the temperature inside the oxidation tower 1 at 80°C, the second heating device 21 maintains the temperature inside the gas-liquid separator 2 at 80°C, and the circulating cooler 52 maintains the internal temperature of the condensation tank 51 at 20°C;

[0086] S4, after the bubble flow in the oxidation tower 1 is stable, the temperature inside the oxidation tower 1 and the temperature inside the gas-liquid separator 2 are both stable at 80° C., and the liquid level inside the gas-liquid separator 2 is stable at 50%, the temperature inside the oxidation tower 1 and the temperature inside the gas-liquid separator 2 are raised to 90-130° C.;

[0087] S5. The reaction pressure control device is used to maintain the pressure inside the oxidation tower 1 at 0-0.4 MPa, and the reaction gas preheated to 80° C. by the preheater 4 is introduced into the oxidation tower 1 at a rate of 0-5 L / min, and the rate of the protective gas is reduced to zero; at the same time, the liquid inside the gas-liquid separator 2 is circulated to the oxidation tower 1 at a rate of 0-20 L / min, and the liquid level of the liquid inside the gas-liquid separator 2 is maintained at 30-65%; wherein, the reading of the oxygen analysis device is controlled to be maintained at 6-8% during the oxidation reaction.

[0088] Example 1

[0089] Based on the above-mentioned isopropylbenzene oxidation reaction system and implementation method, the reaction liquid is an isopropylbenzene mixed liquid containing 3% isopropylbenzene hydroperoxide, the temperature inside the oxidation tower 1 and the temperature inside the gas-liquid separator 2 are raised to 90°C, the gauge pressure inside the oxidation tower 1 is maintained at 0, air is introduced into the oxidation tower 1 at a rate of 2 L / min, and the liquid inside the gas-liquid separator is circulated into the oxidation tower 1 at a rate of 2 L / min. After the reaction continues for 6 hours, the liquid sample is analyzed by liquid chromatography and indirect iodine titration.

[0090] According to the test, the generation rate of CHP was 1.45% / h and the selectivity was 95.5%.

[0091] Example 2

[0092] The process was carried out with reference to Example 1, except that the reaction solution was a cumene mixture containing 5% cumene hydroperoxide.

[0093] According to the test, the generation rate of CHP was 1.55% / h and the selectivity was 95.2%.

[0094] Example 3

[0095] The process was carried out with reference to Example 1, except that the reaction solution was a cumene mixture containing 8% cumene hydroperoxide.

[0096] The results showed that the generation rate of CHP was 1.68% / h and the selectivity was 95.2%.

[0097] Example 4

[0098] The process was carried out with reference to Example 1, except that the reaction solution was a cumene mixture containing 10% cumene hydroperoxide.

[0099] The results showed that the generation rate of CHP was 1.72% / h and the selectivity was 95.0%.

[0100] Example 5

[0101] The process was carried out with reference to Example 1, except that the reaction solution was a cumene mixture containing 15% cumene hydroperoxide.

[0102] According to the test, the generation rate of CHP was 1.75% / h and the selectivity was 94.5%.

[0103] Example 6

[0104] The process was carried out with reference to Example 3, except that the temperature inside the oxidation tower 1 and the temperature inside the gas-liquid separator 2 were raised to 100°C.

[0105] According to the test, the generation rate of CHP was 1.83% / h and the selectivity was 95.3%.

[0106] Example 7

[0107] The process was carried out with reference to Example 6, except that the temperature inside the oxidation tower 1 and the temperature inside the gas-liquid separator 2 were raised to 110°C.

[0108] According to the test, the generation rate of CHP was 1.95% / h and the selectivity was 94.6%.

[0109] Example 8

[0110] The process was carried out with reference to Example 6, except that the temperature inside the oxidation tower 1 and the temperature inside the gas-liquid separator 2 were raised to 120°C.

[0111] The results showed that the generation rate of CHP was 1.90% / h and the selectivity was 94.0%.

[0112] Example 9

[0113] The process was carried out with reference to Example 6, except that the temperature inside the oxidation tower 1 and the temperature inside the gas-liquid separator 2 were raised to 130°C.

[0114] The results showed that the generation rate of CHP was 1.72% / h and the selectivity was 92.2%.

[0115] Example 10

[0116] The process was carried out with reference to Example 6, except that air was introduced into the oxidation tower 1 at a rate of 2 L / min, and the liquid in the gas-liquid separator was circulated into the oxidation tower 1 at a rate of 4 L / min.

[0117] According to the test, the generation rate of CHP was 1.87% / h and the selectivity was 95.0%.

[0118] Example 11

[0119] The method is implemented with reference to Example 6, except that the air is introduced into the oxidation tower 1 at a rate of 2 L / min, and the liquid inside the gas-liquid separator is circulated into the oxidation tower 1 at a rate of 1 L / min.

[0120] According to the test, the generation rate of CHP was 1.80% / h and the selectivity was 95.1%.

[0121] Example 12

[0122] The method was carried out with reference to Example 10, except that the gauge pressure inside the oxidation tower 1 was maintained at 0.2 MPa.

[0123] The results showed that the generation rate of CHP was 2.02% / h and the selectivity was 93.6%.

[0124] Example 13

[0125] The method was carried out with reference to Example 10, except that the gauge pressure inside the oxidation tower 1 was maintained at 0.3 MPa.

[0126] The results showed that the generation rate of CHP was 2.15% / h and the selectivity was 93.3%.

[0127] Example 14

[0128] The method was carried out with reference to Example 10, except that the gauge pressure inside the oxidation tower 1 was maintained at 0.4 MPa.

[0129] The results showed that the generation rate of CHP was 2.21% / h and the selectivity was 92.3%.

[0130] Furthermore, based on the above Examples 1-14, the data results are shown in Table 1 below.

[0131] Table 1

[0132]

[0133] As can be seen from Table 1 above, by adopting the system described in the present invention, by further optimizing the concentration of isopropyl benzene hydroperoxide in the reaction liquid (i.e., CHP initiator concentration), the temperature inside the oxidation tower and the gas-liquid separator (i.e., reaction temperature), the gauge pressure inside the oxidation tower (i.e., reaction gauge pressure), and the introduction rate of gas and reaction liquid (i.e., gas-liquid ratio), the oxidation efficiency of isopropyl benzene is effectively improved, and ultimately the optimal values ​​of CHP generation rate and selectivity are obtained, i.e., the CHP generation rate is 2.15% / h and the selectivity is 93.3%. Specifically, as shown in Example 13, at this time, the concentration of isopropyl benzene hydroperoxide in the reaction liquid is 8%, the temperature inside the oxidation tower and the gas-liquid separator is 100°C, the gauge pressure inside the oxidation tower is 0.3 MPa, and the gas-liquid ratio is 1:2.

[0134] The cumene oxidation reaction system and method provided by the present invention oxidizes cumene through the oxidation tower, separates gas and liquid through the gas-liquid separator, recovers the cumene component in the gas through the condensing equipment, and circulates the liquid into the oxidation tower through the circulation equipment. This can effectively improve the oxidation efficiency of cumene, and has the advantages of high cumene hydroperoxide generation rate, high selectivity and high safety. Furthermore, by cooperating with the oxygen analysis equipment and the gas supply equipment, it can further effectively prevent the oxygen concentration at the top of the gas-liquid separator from being too high and from combusting and exploding with the cumene gas component, thereby having the advantage of higher safety.

[0135] While the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited thereto. Within the technical scope of the present invention, various simple variations of the technical solution of the present invention may be made. To avoid unnecessary repetition, the present invention will not further describe various possible combinations. However, these simple variations and combinations should also be considered as disclosed herein and fall within the scope of protection of the present invention.

Claims

1. A method for oxidation of cumene, characterized in that: The invention comprises an isopropylbenzene oxidation reaction system, wherein the system comprises an oxidation tower (1) and a gas-liquid separator (2); The interior of the oxidation tower (1) is sequentially provided with a bubbling reactor (12) and a micro-bubble generator (11) from top to bottom. The bottom of the oxidation tower (1) is connected to the gas supply device and the liquid supply device respectively, and the top is connected to the gas-liquid separator (2). The top of the gas-liquid separator (2) is connected to the condensation device (5) and the gas supply device respectively. The condensation device (5) is connected to the oxygen analysis device (6). A liquid circulation device is provided between the bottom of the gas-liquid separator (2) and the bottom of the oxidation tower (1) for circulating the liquid inside the gas-liquid separator (2) to the inside of the micro-bubble generator (11). The oxidation tower (1) also includes a first heating device (13) for heating the liquid inside the gas-liquid separator (2) to the inside of the micro-bubble generator (11) during the oxidation reaction of isopropylbenzene. The temperature inside the oxidation tower (1) is maintained at 90-130°C; the gas-liquid separator (2) further includes a second heating device (21) for maintaining the temperature inside the gas-liquid separator (2) at 90-130°C during the cumene oxidation reaction; the condensing device (5) includes a condensing tank (51) and a circulating cooler (52) arranged on the condensing tank (51), and the circulating cooler (52) is used to maintain the temperature inside the condensing tank (51) at 20-40°C; the system further includes a reaction pressure control device for maintaining the gauge pressure inside the oxidation tower (1) at 0-0.4MPa during the cumene oxidation reaction; a preheater (4) is provided between the gas supply device and the oxidation tower (1); The method is implemented based on the system and includes the following steps: S1, the liquid supply device transports the reaction liquid into the oxidation tower (1), and when the interior of the oxidation tower (1) is filled with the reaction liquid and the liquid level of the reaction liquid in the gas-liquid separator (2) reaches 20-30%, the reaction liquid is stopped from being transported into the oxidation tower (1); S2, the liquid circulation device circulates the liquid inside the gas-liquid separator (2) into the oxidation tower (1), and maintains the liquid level inside the gas-liquid separator (2) at 20-60%; S3, the protective gas preheated to 80-90°C by the preheater (4) is introduced into the oxidation tower (1), the first heating device (13) maintains the temperature inside the oxidation tower (1) at 80-90°C, the second heating device (21) maintains the temperature inside the gas-liquid separator (2) at 80-90°C, and the circulating cooler (52) maintains the temperature inside the condensation tank (51) at 20-40°C; S4, after the bubble flow in the oxidation tower (1) is stabilized, the temperature inside the oxidation tower (1) and the temperature inside the gas-liquid separator (2) are both stabilized at 80-90°C, and the liquid level inside the gas-liquid separator (2) is stabilized at 20-60%, the temperature inside the oxidation tower (1) and the temperature inside the gas-liquid separator (2) are raised to 90-130°C; S5. The reaction pressure control device is used to maintain the gauge pressure inside the oxidation tower (1) at 0-0.4 MPa; the reaction gas preheated to 80-90° C. in the preheater (4) is introduced into the oxidation tower (1) at a rate of 0-5 L / min, and the feed rate of the protective gas is reduced to zero. At the same time, the liquid inside the gas-liquid separator (2) is circulated into the oxidation tower (1) at a rate of 0-20 L / min, and the liquid level inside the gas-liquid separator (2) is maintained at 30-65%; wherein, during the oxidation reaction, the reading of the oxygen analysis device (6) is controlled to always be maintained at 6-9.5%.

2. The method according to claim 1, characterized in that The microbubble generator (11) is a ceramic membrane microbubble generator.

3. The method according to claim 2, characterized in that The ceramic membrane of the ceramic membrane microbubble generator has an average pore size of 10 nm to 10 μm, a porosity of 30 to 35%, and a transmembrane pressure difference of 0.2 to 0.5 MPa.

4. The method according to claim 1, wherein The bottom of the condensation tank (51) is connected to the top of the gas-liquid separator (2), and the top is connected to the oxygen analysis equipment (6). A metal wire mesh corrugated filler (511) is provided inside the condensation tank (51).

5. The method according to claim 1, wherein The circulating and transporting of the liquid inside the gas-liquid separator (2) to the inside of the microbubble generator (11) specifically includes: During the cumene oxidation reaction, the liquid inside the gas-liquid separator (2) is circulated and transported to the inside of the microbubble generator (11) at a rate of 0-20 L / min, and the liquid level inside the gas-liquid separator (2) is maintained at 30-65%.

6. The method according to claim 1 or 5, characterized in that The gas supply device is used to deliver protective gas and / or reaction gas to the interior of the microbubble generator (11), and to deliver protective gas to the top of the gas-liquid separator (2).

7. The method according to claim 6, characterized in that The gas supply device is used to introduce reaction gas into the interior of the microbubble generator (11) at a rate of 0-5 L / min during the cumene oxidation reaction.

8. The method according to claim 6, characterized in that The protective gas is an inert gas, and the reactive gas is air.

9. The method according to claim 1, characterized in that The liquid supply device is used to introduce a reaction liquid into the interior of the microbubble generator (11), wherein the reaction liquid is a cumene mixed liquid containing 0-15% cumene hydroperoxide.

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