Reaction system for producing phenol and cyclohexanone, method for producing phenol and cyclohexanone

Abstract

The present application relates to a kind of reaction system for preparing phenol and cyclohexanone, the preparation method of phenol and cyclohexanone.The reaction system includes several constant-temperature reactors and adiabatic reactor connected in sequence;Wherein, the constant-temperature reactor receives reaction raw materials or receives material from previous constant-temperature reactor to occur acidolysis reaction;The adiabatic reactor receives material from previous constant-temperature reactor to occur acidolysis reaction.The reaction system of the present application, several (one or more) constant-temperature reactors are arranged, and an adiabatic reactor is arranged after constant-temperature reactor, by such combination form setting, heat removal mode is reasonable, and the effect of controlling reaction temperature is remarkable;When used for preparing phenol and cyclohexanone, the reaction temperature rise in cyclohexylbenzene peroxide acidolysis reaction can be effectively solved, and cyclohexylbenzene hydrogen peroxide conversion rate and phenol and cyclohexanone selectivity can be improved.

Description

Technical Field

[0001] This invention relates to a reaction system for preparing phenol and cyclohexanone, and a method for preparing phenol and cyclohexanone. Background Technology

[0002] Phenol and cyclohexanone are important basic chemical raw materials used in the production of various high-performance synthetic materials. Besides producing phenolic resins, phenol can be further processed into polycarbonate and epoxy resins via bisphenol A. Cyclohexanone can be used to produce nylon 6 via caprolactam, and nylon 66 via adipic acid and hexamethylenediamine. High-performance synthetic materials such as polycarbonate, high-end epoxy resins, and nylon are widely used in electronics, automotive, and construction industries.

[0003] Currently, the main industrial methods for producing phenol include the toluene-benzoic acid process, the direct oxidation of benzene, and the cumene oxidation process, among which the cumene oxidation process is the most mainstream method. The main problem with industrial phenol production technology is the co-production of low-value-added acetone; the supply and demand imbalance in the phenol and acetone markets restricts the development of the cumene oxidation process. Currently, the main methods for producing cyclohexanone include the cyclohexene hydration method, the phenol hydrogenation method, and the cyclohexane oxidation method; however, all of these methods suffer from drawbacks such as high levels of waste, low conversion rates, and high energy consumption.

[0004] As is well known, phenol and cyclohexanone can be co-produced through a modification of the Hock method. Cyclohexylbenzene is oxidized to obtain cyclohexylbenzene hydrogen peroxide, and then oxidized again and decomposed by an acid catalyst to produce phenol and cyclohexanone. This process route can effectively solve the problem of excess acetone production from the cumene process, and also co-produces cyclohexanone, which has significant industrial value, thus possessing great industrial potential.

[0005] However, the process for oxidative acid hydrolysis of cyclohexylbenzene to produce phenol / cyclohexanone is still in the experimental research stage. Cyclohexylbenzene hydrogen peroxide can be prepared by reacting cyclohexylbenzene with an oxidant in the presence of N-hydroxyphthalimide (NHPI) catalyst. Due to the high boiling point of cyclohexylbenzene, it is difficult to concentrate the hydrogen peroxide using conventional distillation methods; the concentration of hydrogen peroxide in the oxidized product is usually below 30 wt%, which further limits the rate of subsequent acid hydrolysis. Furthermore, under acidic conditions, cyclohexanone undergoes aldol self-condensation more readily than acetone, resulting in a significant decrease in cyclohexanone selectivity. Therefore, it is necessary to optimize the process to improve the conversion rate of cyclohexylbenzene hydrogen peroxide and the selectivity of phenol and cyclohexanone.

[0006] CN201180070218 discloses a method for preparing phenol and cyclohexanone by acidolysis of cyclohexylbenzene with hydrogen peroxide in a FAU-type aluminosilicate catalyst. It was found that by adding 1 ppm to 15,000 ppm of water to the feedstock, the selectivity of cyclohexanone could be increased from 84%–88% to 93%–94%. It is speculated that the presence of water inhibits the byproducts of hexanophenone and phenylcyclohexanol produced by the hydrogen peroxide radical of cyclohexylbenzene. Since the cyclohexanone aldol condensation reaction is an equilibrium reaction, the addition of water can inhibit aldol condensation, thereby mitigating the yield loss of cyclohexanone caused by aldol condensation.

[0007] In the acid hydrolysis of cyclohexylbenzene to produce phenol and cyclohexanone, for solid acid hydrolysis catalysts, the reaction is exothermic, and the continuously released heat causes the catalyst bed temperature to gradually increase as the reaction proceeds. To improve reaction selectivity, a reasonable heat removal method is needed to lower the reaction temperature. Industrial reactors widely employ multi-stage feed quenching or external circulation heat removal to reduce the reaction temperature; however, these methods reduce the concentration of reactants, affecting the yield.

[0008] Another approach is the traditional tubular reactor, where solid catalysts are packed into the tubes. However, problems arise from catalyst swelling, which can easily lead to catalyst breakage and uneven pressure drop in the bed. Chinese patent application CN101279230A discloses a uniform-temperature liquid-solid phase catalytic reactor, primarily addressing the difficulties in removing heat from strongly exothermic reactions, the easy breakage of catalysts due to chemical swelling and thermal expansion, and the varying resistance drop across each tube in existing technologies. However, this invention employs an inverted U-shaped structure, which creates gaps between the disc-shaped distributor and the heat exchange tubes, causing catalyst breakage particles to deposit on the tube support plate.

[0009] Existing literature and reports rarely address the reaction process for the acid hydrolysis of cyclohexylbenzene to produce phenol and cyclohexanone, especially how to effectively reduce the reaction temperature rise, improve the hydrogen peroxide conversion rate of cyclohexylbenzene, and enhance the selectivity of phenol and cyclohexanone. Summary of the Invention

[0010] The reaction of cyclohexylbenzene to produce phenol and cyclohexanone via hydroperoxide is an exothermic reaction. The inventors of this application have discovered that when the reaction temperature exceeds 80°C, the side reactions of cyclohexylbenzene via hydroperoxide increase significantly, and the selectivity of phenol and cyclohexanone decreases significantly.

[0011] In view of the above background, the purpose of this invention is to solve the problems existing in the prior art and provide a reaction system and method for preparing phenol and cyclohexanone, so as to effectively reduce the reaction temperature rise, improve the hydrogen peroxide conversion rate of cyclohexylbenzene, and increase the selectivity of phenol and cyclohexanone. For example, one objective of this invention is to provide a reaction system for preparing phenol and cyclohexanone, which can be applied to the preparation of phenol and cyclohexanone and can better solve the problems of high reaction temperature, low hydrogen peroxide conversion rate of cyclohexylbenzene, and low selectivity of phenol and cyclohexanone in the acidolysis reaction of cyclohexylbenzene peroxide. Another objective of this invention is to provide a method for preparing phenol and cyclohexanone using the above reaction system.

[0012] To achieve the above objectives, a first aspect of the present invention provides a reaction system for preparing phenol and cyclohexanone, comprising a plurality of isothermal reactors and an adiabatic reactor connected in sequence; wherein...

[0013] The isothermal reactor receives reaction raw materials or materials from a previous isothermal reactor to undergo acidolysis.

[0014] The adiabatic reactor receives material from the preceding isothermal reactor for acidolysis.

[0015] In this invention, "a number of" refers to one or more, and the reaction system includes one or more isothermal reactors and one adiabatic reactor. For example, when the reaction system includes two isothermal reactors, the first isothermal reactor receives the reactants to undergo an acidolysis reaction; the second isothermal reactor receives the material from the first isothermal reactor (here, the first isothermal reactor is the aforementioned "previous isothermal reactor") to undergo an acidolysis reaction; and the adiabatic reactor receives the material from the second isothermal reactor (here, the second isothermal reactor is the aforementioned "previous isothermal reactor") to undergo an acidolysis reaction.

[0016] In this invention, when phenol and cyclohexanone are prepared in the reaction system, the reaction raw material is a solution containing cyclohexylbenzene hydrogen peroxide.

[0017] In this invention, the solution containing cyclohexylbenzene hydrogen peroxide is a reaction raw material for the preparation of phenol and cyclohexanone, and can be obtained by contacting cyclohexylbenzene with an oxidant. The solution containing cyclohexylbenzene hydrogen peroxide may include 40 wt% to 99 wt% alkylbenzene and 1 wt% to 60 wt% cyclohexylbenzene hydrogen peroxide; wherein the alkylbenzene is selected from at least one of ethylbenzene, cumene, butadiene, and cyclohexylbenzene.

[0018] In this invention, phenol and cyclohexanone can be co-produced using the reaction system by using a solution containing cyclohexylbenzene hydrogen peroxide as a raw material.

[0019] In this invention, acid hydrolysis can be carried out after acidic solid catalysts (such as acidic resin catalysts and / or aluminosilicate catalysts) are loaded into a constant temperature reactor and an adiabatic reactor.

[0020] In some embodiments of the present invention, the isothermal reactor comprises a plurality of tubular reactors and / or a plurality of fixed-bed reactors with internal heat exchange tubes connected in sequence. That is, each isothermal reactor connected in sequence may be a tubular reactor or a fixed-bed reactor with internal heat exchange tubes (through which a heat dissipation medium, such as cooling water or low-temperature hot water, can be introduced).

[0021] The tubular reactor and the fixed-bed reactor with internal heat exchange tubes of the present invention are both isothermal reactors known in the art, and will not be described in detail here.

[0022] In some embodiments of the present invention, the number of isothermal reactors in the reaction system can be determined based on the amount of catalyst loaded and the throughput. The present invention does not impose a strict limit on the specific number of isothermal reactors.

[0023] The inventors of this invention discovered that the acidolysis reaction of cyclohexylbenzene peroxide is a moderately exothermic reaction. When the temperature exceeds 80°C, it leads to an increase in side reactions and a decrease in product selectivity. When the temperature is too low, it leads to a lower reaction rate and an increase in catalyst loading. The reaction system of this invention, however, sets up several (or more) isothermal reactors, with an adiabatic reactor following each isothermal reactor. This combination allows the isothermal reactors to process over 90% of the reactants, ensuring product selectivity, while the adiabatic reactor processes the remaining reactants, ensuring the conversion rate of the reactants. The combination of these two systems significantly improves the conversion rate of the reaction raw materials (a solution containing cyclohexylbenzene hydrogen peroxide) and the selectivity of phenol and cyclohexanone. Furthermore, the heat removal method is reasonable and effectively controls the reaction temperature.

[0024] A second aspect of the present invention provides a method for preparing phenol and cyclohexanone, comprising the steps of: continuously passing a solution containing cyclohexylbenzene hydrogen peroxide through a reaction system described in the first aspect above, which is packed with an acidic solid catalyst, to produce phenol and cyclohexanone.

[0025] In some embodiments of the present invention, the solution containing cyclohexylbenzene hydrogen peroxide comprises 40 wt% to 99 wt% alkylbenzene and 1 wt% to 60 wt% cyclohexylbenzene hydrogen peroxide; wherein the alkylbenzene is selected from at least one of ethylbenzene, cumene, butadiene, and cyclohexylbenzene. The solution containing cyclohexylbenzene hydrogen peroxide can be prepared by contacting cyclohexylbenzene with an oxidizing agent.

[0026] In some embodiments of the present invention, the acidic solid catalyst is an acidic resin catalyst (acidic ion exchange resin catalyst) and / or an aluminosilicate catalyst.

[0027] In some embodiments of the present invention, the acidic solid catalyst is disposed on the shell side of the isothermal reactor and the adiabatic reactor (e.g., Figure 1 (8) Catalyst bed. In this invention, by placing the catalyst on the shell side of the reactor, the swelling and breakage of the catalyst can be effectively prevented. For example, acidic resin catalysts, due to their swelling characteristics, can have a swelling rate of up to 50%, and placing them on the shell side of the reactor can effectively prevent swelling and breakage.

[0028] In some embodiments of the present invention, the material containing the cyclohexylbenzene hydrogen peroxide solution and / or the material from the preceding isothermal reactor passes through several isothermal reactors and the adiabatic reactor from bottom to top. In the present invention, the material containing the cyclohexylbenzene hydrogen peroxide solution and / or the material from the preceding isothermal reactor may also pass through several isothermal reactors and the adiabatic reactor from top to bottom; however, using a bottom-up flow method reduces bed pressure drop and prevents catalyst breakage.

[0029] In some embodiments of the present invention, the conditions for the acidolysis reaction to occur in the reaction system include: a temperature of 20°C to 150°C, preferably 50°C to 80°C; and a pressure of 100 kPa to 2000 kPa, preferably 100 kPa to 300 kPa.

[0030] In some embodiments of the present invention, in several of the constant temperature reactors, the inlet material temperature is higher than 50°C and the outlet material temperature is lower than 80°C; preferably, the inlet material temperature and the outlet material temperature are 60°C to 70°C, respectively.

[0031] In some embodiments of the present invention, in the adiabatic reactor, the inlet material temperature is higher than 40°C and the outlet material temperature is lower than 100°C; preferably, the inlet material temperature is higher than 60°C and the outlet material temperature is lower than 80°C.

[0032] This invention does not impose strict limitations on the mass hourly space velocity (MHV) of cyclohexylbenzene peroxide (i.e., cyclohexylbenzene peroxide in a solution containing cyclohexylbenzene peroxide). Those skilled in the art can define the MHV based on the type of catalyst. For example, when using an acidic resin catalyst, the MHV of cyclohexylbenzene peroxide relative to the catalyst loading should not exceed 0.8 h⁻¹. -1 This achieves the technical effects corresponding to the acid hydrolysis reaction.

[0033] Compared with the prior art, the beneficial effects of the present invention include:

[0034] (1) The reaction system for preparing phenol and cyclohexanone provided by the present invention is provided with several (one or more) constant temperature reactors, and an adiabatic reactor is set after the constant temperature reactors. With such a combination, the constant temperature reactor can process more than 90% of the reactants to ensure the selectivity of the products, and the adiabatic reactor can process the remaining reactants to ensure the conversion rate of the reactants. The combination of the two can significantly improve the conversion rate of the reactants and the selectivity of phenol and cyclohexanone; and the heat removal method is reasonable and effectively controls the reaction temperature.

[0035] (2) The method for preparing phenol and cyclohexanone provided by the present invention is a combination of several constant temperature reactors and adiabatic reactors. In the constant temperature reactor, the conversion rate of cyclohexylbenzene hydrogen peroxide is ≥70%, and the remaining cyclohexylbenzene hydrogen peroxide is further converted in the adiabatic reactor.

[0036] (3) The preparation method of phenol and cyclohexanone provided by the present invention can effectively solve the problem of reaction temperature rise in the acid hydrolysis reaction of cyclohexylbenzene peroxide, and can improve the hydrogen peroxide conversion rate of cyclohexylbenzene and the selectivity of phenol and cyclohexanone. Attached Figure Description

[0037] The present invention will now be described in further detail with reference to the accompanying drawings.

[0038] Figure 1 This is a schematic diagram of the reaction system and material flow direction in an embodiment of the present invention.

[0039] Figure 1 In this diagram, R1 is a constant-temperature U-shaped tubular reactor; R2 is an adiabatic fixed-bed reactor; E1 is a feed preheater; E2 is an interstage cooler; S1 and S2 are heat transfer media; S3 and S4 are heat removal media; S5 and S6 are coolant; 1 is cyclohexylbenzene hydrogen peroxide solution; 2 is the inlet material of constant-temperature reactor R1; 3 is the outlet material of constant-temperature reactor R1; 4 is the inlet material of adiabatic reactor R2; 5 is the outlet material of adiabatic reactor R2; 6 is a U-shaped heat exchange tube; 7 is a feed distribution plate; and 8 is a catalyst bed. Detailed Implementation

[0040] To make the present invention easier to understand, the present invention will be described in detail below with reference to embodiments and accompanying drawings. These embodiments are for illustrative purposes only and are not limited to the scope of application of the present invention.

[0041] In the following examples, the catalyst packed in each reactor is an acidic ion exchange resin catalyst, brand name Amberlyst-15.

[0042] In the following embodiments, the product selectivity and feed conversion rate are calculated using the following methods:

[0043] (1) Conversion rate of cyclohexylbenzene peroxide:

[0044]

[0045] In the formula, x CHBHP The conversion rate of cyclohexylbenzene peroxide is expressed in %; The mass fraction of cyclohexylbenzene peroxide at the reactor inlet is expressed in wt%. The mass fraction of cyclohexylbenzene peroxide at the reactor outlet, in wt%.

[0046] (2) Phenol selectivity:

[0047]

[0048] In the formula, S PH Selectivity for phenol, in %; and Molar flow rates of phenol at reactor outlet and inlet, in kmol / h; and Molar flow rates of cyclohexylbenzene peroxide at the reactor inlet and outlet, in kmol / h;

[0049] (3) Cyclohexanone selectivity:

[0050]

[0051] In the formula, S CYC Selectivity of cyclohexanone, in %; and The molar flow rates of cyclohexanone at the reactor outlet and inlet are expressed in kmol / h. and Molar flow rates of cyclohexylbenzene peroxide at the reactor inlet and outlet, in kmol / h;

[0052] Example 1

[0053] like Figure 1 As shown, Example 1 provides a reaction system for preparing phenol and cyclohexanone, comprising a feed preheater E1, a constant-temperature U-shaped tubular reactor R1, an interstage cooler E2, and an adiabatic fixed-bed reactor R2 connected in sequence.

[0054] In this process, the feed preheater E1 uses S1 and S2 as heat transfer media to preheat the cyclohexylbenzene hydrogen peroxide solution 1, which is called the inlet material 2 of the constant temperature reactor R1. The inlet material 2 of the constant temperature reactor R1 is introduced into the constant temperature reactor R1, and after being distributed by the feed distribution plate 7, it comes into contact with the catalyst bed 8 packed on the shell side for reaction. The U-shaped heat exchange tube 6 uses heat removal media S3 and S4 to remove heat and control the temperature of the outlet material 3 of the constant temperature reactor R1.

[0055] Interstage cooler E2 cools the outlet material 3 of isothermal reactor R1 through refrigerants S5 and S6 to obtain inlet material 4 of adiabatic reactor R2, which is then introduced into adiabatic reactor R2 with catalyst bed 8 packed on the shell side, and finally obtains outlet material 5 of adiabatic reactor R2.

[0056] Example 2

[0057] Example 2 uses the reaction system of Example 1 to prepare phenol and cyclohexanone.

[0058] The preparation method of phenol and cyclohexanone in this embodiment includes the following steps:

[0059] A solution containing 26 wt% cyclohexylbenzene hydrogen peroxide (the remaining 84 wt% being cyclohexylbenzene) was fed at a rate of 12 kg / h into an acidolysis system consisting of a isothermal U-tube reactor R1 and an adiabatic fixed-bed reactor R2 connected in series to prepare phenol and cyclohexanone. The catalyst loading in the isothermal U-tube reactor R1 was 3.5 kg, and the catalyst loading in the adiabatic fixed-bed reactor R2 was 1 kg. The mass hourly space velocity (WHSV) of the cyclohexylbenzene peroxide relative to the total catalyst loading was 0.69 h⁻¹. -1 .

[0060] Solution 1 is preheated to 60°C by feed preheater E1 (through heat mediums S1 and S2) to obtain inlet material 2 of constant temperature reactor R1. Inlet material 2 of constant temperature reactor R1 is introduced from the bottom of constant temperature U-shaped tubular reactor R1, and after being distributed by feed distribution plate 7, it comes into contact with the catalyst bed 8 packed on the shell side for reaction. The heat released by the reaction is removed through U-shaped heat exchange tube 6.

[0061] By controlling the flow rate and temperature of the heat removal medium (heat removal media S3 and S4) in the U-shaped heat exchanger tube 6, the temperature of the material 3 at the outlet of the isothermal reactor R1 is kept to approximately 70°C. Subsequently, the material 3 at the outlet of the isothermal reactor R1 is cooled to 60°C by the interstage cooler E2 (through refrigerants S5 and S6) to obtain the material 4 at the inlet of the adiabatic reactor R2. The material 4 at the inlet of the adiabatic reactor R2 is introduced from the bottom of the adiabatic fixed-bed reactor R2 into the adiabatic fixed-bed reactor R2 filled with catalyst, and flows and reacts from bottom to top. Finally, the material 5 at the outlet of the adiabatic reactor R2 flows out from the top of the reactor at a temperature of 65°C.

[0062] The conversion rate of cyclohexylbenzene to hydrogen peroxide was determined to be 99.1%, the selectivity for phenol was 91.2%, and the selectivity for cyclohexanone was 88%.

[0063] Example 3

[0064] Example 3 is basically the same as Example 2, except that: the feed preheater E1 (through heat mediums S1 and S2) preheats to 50°C; the temperature of the material 3 at the outlet of the constant temperature reactor R1 is about 70°C by controlling the flow rate and temperature of the heat removal medium (heat removal mediums S3 and S4) in the U-shaped heat exchange tube 6.

[0065] The conversion rate of cyclohexylbenzene to hydrogen peroxide was determined to be 98.3%, the selectivity for phenol was 91.7%, and the selectivity for cyclohexanone was 88.6%.

[0066] Example 4

[0067] Example 4 is basically the same as Example 2, except that: the feed preheater E1 (through heat mediums S1 and S2) preheats to 70°C; the temperature of the material 3 at the outlet of the constant temperature reactor R1 is about 80°C by controlling the flow rate and temperature of the heat removal medium in the U-shaped heat exchange tube 6.

[0068] The conversion rate of cyclohexylbenzene to hydrogen peroxide was determined to be 99.6%, the selectivity for phenol was 90.3%, and the selectivity for cyclohexanone was 86.5%.

[0069] Example 5

[0070] Example 5 is basically the same as Example 2, except that the interstage cooler E2 (through refrigerants S5 and S6) is not activated for the outlet material 3 of the isothermal reactor R1, meaning the temperature of the inlet material 4 of the adiabatic fixed-bed reactor R2 is 70°C. Finally, the outlet material 5 of the adiabatic reactor R2 flows out from the top outlet of the reactor at a temperature of approximately 75°C.

[0071] The conversion rate of cyclohexylbenzene to hydrogen peroxide was determined to be 99.3%, the selectivity for phenol was 90.7%, and the selectivity for cyclohexanone was 86.8%.

[0072] Comparative Example 1

[0073] Comparative Example 1 is basically the same as Example 1, except that the reaction system of Comparative Example 1 does not include the interstage cooler E2 and the adiabatic fixed-bed reactor R2.

[0074] Comparative Example 2

[0075] Comparative Example 2 uses the reaction system of Comparative Example 1 to prepare phenol and cyclohexanone.

[0076] The preparation method of Comparative Example 2 is basically the same as that of Example 2, except that the reactants pass through the isothermal reactor R1 only and not through the adiabatic fixed-bed reactor R2; the temperature of the material 2 at the inlet of the isothermal reactor R1 is about 60°C and the temperature of the material 3 at the outlet of the isothermal reactor R1 is about 75°C.

[0077] The conversion rate of cyclohexylbenzene to hydrogen peroxide was determined to be 96.1%, the selectivity for phenol was 90.5%, and the selectivity for cyclohexanone was 86.1%.

[0078] Comparative Example 3

[0079] Comparative Example 3 is basically the same as Example 2, except that the temperature of the material 3 at the outlet of the constant temperature reactor R1 is about 105°C by controlling the flow rate and temperature of the heat removal medium (heat removal medium S3 and S4) in the U-shaped heat exchange tube 6.

[0080] The conversion rate of cyclohexylbenzene to hydrogen peroxide was determined to be 99.8%, the selectivity for phenol was 78.3%, and the selectivity for cyclohexanone was 65.1%.

[0081] Comparative Example 4

[0082] Comparative Example 4 is basically the same as Example 2, except that: the temperature of the inlet material 2 of the isothermal reactor R1 is about 40°C (the reaction raw materials are preheated to about 40°C); the temperature of the outlet material 3 of the isothermal reactor R1 is about 50°C; the temperature of the inlet material 4 of the adiabatic fixed-bed reactor R2 is about 50°C; and finally, the outlet material 5 of the adiabatic reactor R2 flows out from the top outlet of the reactor at a temperature of about 83°C.

[0083] The conversion rate of cyclohexylbenzene to hydrogen peroxide was determined to be 95.3%, the selectivity for phenol was 88.3%, and the selectivity for cyclohexanone was 84.1%.

[0084] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A method for preparing phenol and cyclohexanone, comprising the steps of: continuously passing a solution containing cyclohexylbenzene hydrogen peroxide through a reaction system for preparing phenol and cyclohexanone packed with an acidic solid catalyst to undergo an acidolysis reaction, thereby generating phenol and cyclohexanone; the reaction system for preparing phenol and cyclohexanone comprises a plurality of isothermal reactors and an adiabatic reactor connected in sequence; wherein, The isothermal reactor receives reaction raw materials or materials from a previous isothermal reactor to undergo acidolysis. The adiabatic reactor receives material from the preceding isothermal reactor for acidolysis. In several of the aforementioned isothermal reactors, the inlet material temperature and the outlet material temperature are 60℃~70℃, respectively; In the adiabatic reactor, the inlet material temperature is greater than or equal to 60°C, and the outlet material temperature is less than 80°C. The acidic solid catalyst is an acidic resin catalyst and / or an aluminosilicate catalyst; the acidic solid catalyst is disposed on the shell side of the isothermal reactor and the adiabatic reactor.

2. The preparation method according to claim 1, characterized in that, The isothermal reactor comprises a number of tubular reactors and / or a number of fixed-bed reactors with internal heat exchange tubes connected in sequence.

3. The preparation method according to claim 1, characterized in that, The solution containing cyclohexylbenzene hydrogen peroxide comprises 40 wt% to 99 wt% alkylbenzene and 1 wt% to 60 wt% cyclohexylbenzene hydrogen peroxide; wherein the alkylbenzene is selected from at least one of ethylbenzene, cumene, butadiene, and cyclohexylbenzene.

4. The preparation method according to claim 1, characterized in that, The material containing a solution of cyclohexylbenzene hydrogen peroxide and / or the material from the previous isothermal reactor passes from bottom to top through several of the isothermal reactors and the adiabatic reactor.

5. The preparation method according to any one of claims 1-4, characterized in that, In the reaction system, the conditions for the acidolysis reaction to occur include: a temperature of 20°C to 150°C and a pressure of 100 kPa to 2000 kPa.

6. The preparation method according to claim 5, characterized in that, In the reaction system, the conditions for the acidolysis reaction to occur include: a temperature of 50°C to 80°C and a pressure of 100 kPa to 300 kPa.

7. The preparation method according to any one of claims 1-4, characterized in that, In the adiabatic reactor, the inlet material temperature is higher than 60°C.

Images