Jet circulation system and preparation method of aromatic alcohol

Abstract

The invention provides a jet circulation system and a preparation method of aromatic alcohol, and belongs to the field of aromatic alcohol synthesis. The bottoms of the reaction kettle and the heat exchanger are conical, so that accumulation of a catalyst in the reaction kettle and the heat exchanger can be avoided, the reaction rate is increased, and the yield of a product is ensured; the catalyst can be efficiently recovered by adopting the hydrocyclone, and a sand settling opening in the bottom of the hydrocyclone is connected with a straight pipe section structure, so that the loss of the catalyst is reduced; the Venturi ejector is adopted, and the swirler is mounted at the upper part of the main flow nozzle of the ejector, so that the gas absorption coefficient is improved, the reaction rate is further improved, and meanwhile, the yield and purity of aromatic alcohol are improved. When the device provided by the invention is used for preparing the aromatic alcohol, the catalyst can be recycled, the conversion rate of the aromatic ketone is up to 99.8%, the yield of the aromatic alcohol can reach 97.5%, the yield of byproducts can be as low as 0.5% or below, and the device has high raw material conversion rate, product yield and purity.

Description

Technical Field

[0001] The present invention relates to the field of synthesis of aromatic alcohols, and particularly to an ejector loop system and a method for preparing aromatic alcohols. Background Art

[0002] Currently, the most advanced method for synthesizing aromatic alcohols is to prepare aromatic alcohols by catalytic hydrogenation of aromatic ketones. In industrial production, hydrogen is commonly used as the hydrogen source, and solid catalysts are used for catalysis. For gas-liquid-solid three-phase hydrogenation reactions, it is of great significance to select a suitable hydrogenation reactor. The stirred tank reactor (STR) is widely used as a traditional reactor and performs well in the treatment of reactions such as liquid, gas, and solid-liquid phases. However, when the gas-liquid-solid three-phase reaction is carried out in an industrial-scale STR, problems such as mass transfer limitations, solid-liquid separation, mechanical stirring difficulties, and low heat transfer efficiency are usually encountered. Therefore, the STR is not the first choice in industrial production.

[0003] Stirred reactors and fixed-bed reactors are commonly used reaction equipment in the industrial production of aromatic alcohols. Stirred reactors can provide good mixing effects, enabling the reactants to come into full contact and increasing the reaction rate. However, stirred reactors have high energy consumption, and for large-scale production, the equipment investment and maintenance costs are relatively high. Fixed-bed reactors have a simple structure and convenient operation and are suitable for continuous production. However, fixed-bed reactors have poor heat transfer effects, easily leading to local overheating, which affects the reaction stability and the quality of the products.

[0004] In related research, the main component of the catalyst used for the catalytic hydrogenation of aromatic ketones to prepare aromatic alcohols is Raney nickel. Raney nickel catalysts are prone to spontaneous combustion in the air, have certain dangers, and are also likely to deactivate the catalyst, resulting in a decrease in the reaction rate and a decline in the raw material conversion rate, product yield, and purity. Summary of the Invention

[0005] The purpose of the present invention is to provide an ejector loop system and a method for preparing aromatic alcohols. The ejector loop system provided by the present invention can increase the reaction rate when preparing aromatic alcohols, and can also increase the raw material conversion rate, product yield, and purity.

[0006] To achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0007] The present invention provides an ejector loop system, comprising a reaction kettle 1, a circulation pump 2, a heat exchanger 3, a hydrocyclone 4, a Venturi ejector 5, and a cyclone 6;

[0008] The top of the reactor 1 is respectively provided with a first feed inlet, a catalyst feed inlet and an injection feed inlet; the injection feed inlet is provided with a Venturi injector 5, and the bottom of the Venturi injector 5 is inserted into the interior of the reactor 1; a cyclone 6 is installed above the main nozzle of the Venturi injector 5;

[0009] The bottom of the reactor 1 is conical; the bottom of the reactor 1 is provided with a first discharge outlet;

[0010] The bottom of the heat exchanger 3 is conical; the bottom of the heat exchanger 3 is provided with a second feed inlet; the first discharge outlet and the second feed inlet are connected by a circulation pump 2;

[0011] The top of the heat exchanger 3 is provided with a second discharge outlet; the second discharge outlet is respectively connected to the feed inlet of the hydrocyclone 4 and the feed inlet of the Venturi injector 5; a first valve V-4 is provided between the second discharge outlet and the feed inlet of the hydrocyclone 4;

[0012] The top of the hydrocyclone 4 is provided with a third discharge outlet; the bottom of the hydrocyclone 4 is provided with a sand settling port, and the sand settling port is connected with a straight pipe section structure; the straight pipe section structure is connected to the catalyst feed inlet.

[0013] Preferably, the conical inclination angles of the bottoms of the reactor 1 and the heat exchanger 3 are independently 45 to 70°;

[0014] Preferably, the ratio of the diameter of the mixing section to the diameter of the nozzle in the Venturi injector 5 is (1.5 to 3):1;

[0015] The length-diameter ratio of the mixing section in the Venturi injector 5 is 8 to 15.

[0016] The present invention also provides a jet loop system device, including one or more sets of the jet loop systems described in the above technical solutions;

[0017] When the jet loop system device includes multiple sets of jet loop systems, the multiple sets of jet loop systems are connected in series;

[0018] The series connection method is: the third discharge outlet of the hydrocyclone in the upper-stage jet loop system is connected to the first feed inlet of the reactor in the lower-stage jet loop system.

[0019] The present invention also provides a method for preparing an aromatic alcohol. Using the device described in the above technical solution, when the jet circulation system device includes a set of jet circulation systems, the method for preparing the aromatic alcohol includes: introducing a raw material and a catalyst into a reaction kettle through a first feed port to obtain a reaction solution; the liquid level of the reaction solution is higher than the bottom of the Venturi ejector; closing the first valve, under the action of a circulation pump, the reaction solution enters a heat exchanger through a first discharge port and a second feed port for heating, and then enters the Venturi ejector through a second discharge port. At the same time, hydrogen is introduced into the Venturi ejector and reacts with the reaction solution entering the Venturi ejector. Under the action of a cyclone, the mixture is sprayed into the reaction kettle to form a jet circulation for a reduction reaction; after the reduction reaction is completed, the first valve is opened, and the obtained product enters a hydrocyclone for solid-liquid separation to obtain a liquid-phase product aromatic alcohol and a solid-phase catalyst; the liquid-phase product aromatic alcohol is discharged through a third discharge port to obtain the aromatic alcohol; the raw material is an aromatic ketone; the solid-phase catalyst enters a straight pipe section structure through a sand settling port, and then enters the reaction kettle through a catalyst feed port for recycling;

[0020] When the jet circulation system device includes multiple sets of jet circulation systems, the method for preparing the aromatic alcohol includes: introducing a raw material and a catalyst into a reaction kettle through a first feed port of a first-stage jet circulation system to obtain a reaction solution; opening the first valve, under the action of a circulation pump, the reaction solution enters a heat exchanger through a first discharge port and a second feed port for heating, and then enters a hydrocyclone and a Venturi ejector respectively through a second discharge port. At the same time, hydrogen is introduced into the Venturi ejector and reacts with the reaction solution entering the Venturi ejector. Under the action of a cyclone, the mixture is sprayed into the reaction kettle to form a jet circulation for a reduction reaction; the reaction solution entering the hydrocyclone is subjected to solid-liquid separation in the hydrocyclone to obtain a liquid phase and a solid-phase catalyst; the obtained solid-phase catalyst enters a straight pipe section structure through a sand settling port, and then enters the reaction kettle through a catalyst feed port for recycling; the obtained liquid phase is discharged through a third discharge port and used as a raw material. Together with the catalyst, it is introduced into the reaction kettle through a first feed port of the next-stage jet circulation system to obtain a reaction solution, and the operation in the first-stage jet circulation system is repeated to form a circulation for a reduction reaction; the last-stage jet circulation system adopts the same operation as that of the jet circulation system device with a set of jet circulation systems to obtain the aromatic alcohol; the liquid level of the reaction solution in each stage of the jet circulation system is higher than the bottom of the corresponding Venturi ejector.

[0021] Preferably, the addition amount of the catalyst in each stage of the jet circulation system is independently 1-10% of the mass of the raw material.

[0022] Preferably, the jet velocity of the jet circulation in each stage of the jet circulation system is independently 15-60 m / s.

[0023] Preferably, when the jet circulation system device includes a set of jet circulation systems, the volume ratio of the circulation amount of the jet circulation in the jet circulation system to the volume of the raw material is (20 - 100):1;

[0024] When the jet circulation system device includes multiple sets of jet circulation systems, the volume ratio of the circulation amount of the jet circulation in the last-stage jet circulation system to the volume of the raw material is (20 - 100):1.

[0025] Preferably, the temperature of the reduction reaction in each stage of the jet circulation system is independently 40 - 80 °C, and the pressure of the reduction reaction is independently 1.0 - 2.5 MPa.

[0026] Preferably, the filling rate of the reaction liquid in the reaction kettle in each stage of the jet circulation system is independently 40 - 70%.

[0027] The present invention provides an injection circulation system, which includes a reaction kettle 1, a circulation pump 2, a heat exchanger 3, a hydrocyclone 4, a Venturi injector 5 and a cyclone 6; the top of the reaction kettle 1 is respectively provided with a first feed inlet, a catalyst feed inlet and an injection feed inlet; the injection feed inlet is provided with a Venturi injector 5, and the bottom of the Venturi injector 5 is inserted into the interior of the reaction kettle 1; a cyclone 6 is installed above the main nozzle of the Venturi injector 5; the bottom of the reaction kettle 1 is conical; the bottom of the reaction kettle 1 is provided with a first discharge outlet; the bottom of the heat exchanger 3 is conical; the bottom of the heat exchanger 3 is provided with a second feed inlet; the first discharge outlet and the second feed inlet are connected through a circulation pump 2; the top of the heat exchanger 3 is provided with a second discharge outlet; the second discharge outlet is respectively connected to the feed inlet of the hydrocyclone 4 and the feed inlet of the Venturi injector 5; a first valve V-4 is provided between the second discharge outlet and the feed inlet of the hydrocyclone 4; the top of the hydrocyclone 4 is provided with a third discharge outlet; the bottom of the hydrocyclone 4 is provided with a sand settling port, and the sand settling port is connected with a straight pipe section structure; the straight pipe section structure is connected to the catalyst feed inlet. In the present invention, the bottoms of the reaction kettle 1 and the heat exchanger 3 are set to be conical, which can avoid the accumulation of the catalyst in the reaction kettle and the heat exchanger, thereby fully utilizing the catalyst, increasing the reaction rate and ensuring the product yield; the hydrocyclone is used to efficiently recover the catalyst, and connecting the sand settling port at the bottom of the hydrocyclone 4 with a straight pipe section structure can ensure that the catalyst particles are completely covered by the liquid, avoid spontaneous combustion caused by contact with air, and reduce the loss of the catalyst; by using a Venturi injector and installing a cyclone above the main nozzle of the injector, the gas absorption coefficient can be increased, thereby increasing the reaction rate, and at the same time increasing the yield and purity of the aromatic alcohol. The results of the examples show that using the device provided by the present invention to prepare aromatic alcohol can recycle the catalyst, and the conversion rate of aromatic ketone can be as high as 99.8%, the yield of aromatic alcohol can reach 97.5%, and the yield of by-products can be as low as less than 0.5%, having high raw material conversion rate, product yield and purity. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic structural diagram of the injection circulation system device in Example 4 of the present invention; wherein, 1 is a reaction kettle, 2 is a circulation pump, 3 is a heat exchanger, 4 is a hydrocyclone, 5 is a Venturi injector, 6 is a cyclone, V-1 is the third valve, V-2 is the fourth valve, V-3 is the second valve, V-4 is the first valve, V-5 is the fifth valve;

[0029] Figure 2Schematic structural diagram of the jet loop system device according to Embodiment 5 of the present invention; wherein, 1 and 7 are reaction kettles, 2 and 8 are circulation pumps, 3 and 9 are heat exchangers, 4 and 10 are hydrocyclones, 5 and 11 are Venturi injectors, 6 and 12 are cyclones, V-1 and V-6 are the third valves, V-2 and V-7 are the fourth valves, V-3 and V-8 are the second valves, V-4 and V-9 are the first valves, and V-5 and V-10 are the fifth valves. Detailed implementation manners

[0030] The present invention provides a jet loop system device, including a reaction kettle 1, a circulation pump 2, a heat exchanger 3, a hydrocyclone 4, a Venturi injector 5, and a cyclone 6.

[0031] As Figure 1 shown, the jet loop system device provided by the present invention includes a reaction kettle 1; a first feed inlet, a catalyst feed inlet, and a jet feed inlet are respectively provided at the top of the reaction kettle 1. In the present invention, the first feed inlet is used to introduce raw materials and an initial catalyst, the catalyst feed inlet is used to introduce a recycled catalyst, and the jet feed inlet is used for the jet of hydrogen and a circulating reaction liquid.

[0032] As Figure 1 shown, in the present invention, a Venturi injector 5 is provided at the jet feed inlet, and the bottom of the Venturi injector 5 is inserted into the interior of the reaction kettle 1. By providing the Venturi injector in the present invention, the characteristics of the Venturi injector can be utilized to improve the reaction efficiency of the system.

[0033] As an implementation manner of the present invention, the position where the bottom of the Venturi injector 5 is inserted into the interior of the reaction kettle 1 is calculated starting from the bottom of the cylindrical section of the reaction kettle, and it can be located at 10-50% of the total height of the cylindrical section of the reaction kettle, or it can also be 20-30%. Limiting the position where the bottom of the Venturi injector 5 is inserted into the interior of the reaction kettle 1 within the above range in the present invention can immerse the bottom of the Venturi injector 5 below the reaction liquid level in the reaction kettle.

[0034] As Figure 1 shown, in the present invention, a cyclone 6 is installed above the main nozzle of the Venturi injector 5. By installing a cyclone above the main nozzle of the Venturi injector in the present invention, the gas absorption coefficient can be improved, thereby increasing the reaction rate.

[0035] As an embodiment of the present invention, the ratio of the diameter of the mixing section to the diameter of the nozzle in the Venturi ejector 5 can be (1.5 - 3):1, or can also be (2 - 2.5):1; the aspect ratio of the mixing section in the Venturi ejector 5 can be 8 - 15, or can also be 10 - 13, or can also be 11 - 12. The present invention limits the ratio of the diameter of the mixing section to the diameter of the nozzle and the aspect ratio of the mixing section in the Venturi ejector within the above ranges to ensure that the liquid-solid-gas three can be fully and evenly mixed.

[0036] As Figure 1 shown, in the embodiment of the present invention, a first air inlet is further provided at the top of the reaction kettle 1; the present invention provides a first air inlet at the top of the reaction kettle 1 to introduce hydrogen, which can ensure that the reaction kettle maintains an appropriate pressure during the reduction reaction process.

[0037] As Figure 1 shown, in the present invention, the bottom of the reaction kettle 1 is conical; a first discharge port is provided at the bottom of the reaction kettle 1. As an embodiment of the present invention, the conical inclination angle at the bottom of the reaction kettle 1 can be 45 - 70°, or can also be 50 - 65°, or can also be 55 - 60°. The present invention sets the bottom of the reaction kettle 1 as conical and sets the conical inclination angle within the above range to avoid catalyst sedimentation, which is beneficial to the recycling of the catalyst and improves the reaction rate.

[0038] As Figure 1 shown, the jet loop system device provided by the present invention further includes a heat exchanger 3; the bottom of the heat exchanger 3 is conical; a second feed port is provided at the bottom of the heat exchanger 3. The present invention can heat the reaction liquid through the heat exchanger and ensure an appropriate reduction reaction temperature.

[0039] As Figure 1 shown, in the present invention, a second discharge port is provided at the top of the heat exchanger 3; the second discharge port is respectively communicated with the feed port of the hydrocyclone 4 and the feed port of the Venturi ejector 5; a fifth valve V-5 is provided between the second discharge port and the feed port of the Venturi ejector 5. The present invention can make all the products of the final reduction reaction enter the hydrocyclone 4 for separation by setting the fifth valve V-5.

[0040] As Figure 1 shown, the jet loop system device provided by the present invention further includes a circulation pump 2; the first discharge port and the second feed port are communicated through the circulation pump 2. The present invention can achieve jet circulation by setting the circulation pump.

[0041] The present invention has no special limitation on the connection mode between the first discharge port, the second feed port and the circulation pump, and a closed channel connection well-known to those skilled in the art can be adopted; in the embodiment of the present invention, it can be connected through a conduit.

[0042] As Figure 1 shown, the jet loop system device provided by the present invention further includes a hydrocyclone 4; the second discharge port is communicated with the feed port of the hydrocyclone 4; a first valve V-4 is provided between the second discharge port and the feed port of the hydrocyclone 4. In the present invention, the hydrocyclone can achieve solid-liquid separation; by setting the first valve V-4, the circulation path of the liquid phase before and after the reduction reaction is controlled.

[0043] As Figure 1 shown, in the present invention, a third discharge port is provided at the top of the hydrocyclone 4. In an embodiment of the present invention, a second valve V-3 is provided at the third discharge port. In the present invention, the second valve is opened when it is necessary to export the liquid phase product from the third discharge port of the jet loop system.

[0044] As Figure 1 shown, in the present invention, a sand settling port is provided at the bottom of the hydrocyclone 4, and the sand settling port is connected with a straight pipe section structure; the straight pipe section structure is communicated with the circulating feed port. In the present invention, the sand settling port can collect the solid catalyst to realize the recycling or recovery of the solid catalyst; by setting the straight pipe section structure, it can be ensured that the catalyst particles are completely covered by the liquid, avoiding spontaneous combustion caused by contact with air and reducing the loss of the catalyst.

[0045] As Figure 1 shown, in an embodiment of the present invention, a third valve V-1 is provided between the straight pipe section structure and the circulating feed port. The present invention can control the timing of adding the solid catalyst into the reaction kettle by setting the third valve.

[0046] As Figure 1 shown, in an embodiment of the present invention, a solid discharge port is further provided on the straight pipe section structure; a fourth valve V-2 is provided at the solid discharge port. The present invention can realize the recovery of the solid catalyst by setting the fourth valve.

[0047] In the present invention, setting the bottoms of the reaction kettle 1 and the heat exchanger 3 to be conical can avoid the accumulation of the catalyst in the reaction kettle and the heat exchanger, thereby fully utilizing the catalyst, increasing the reaction rate and ensuring the product yield; adopting a hydrocyclone can efficiently recycle the catalyst, and connecting the sand settling port at the bottom of the hydrocyclone 4 with a straight pipe section structure can ensure that the catalyst particles are completely covered by the liquid, avoiding spontaneous combustion caused by contact with air and reducing the loss of the catalyst; by adopting a Venturi ejector and installing a cyclone above the main nozzle of the ejector, the gas absorption coefficient can be increased, thereby increasing the reaction rate and simultaneously increasing the yield and purity of the aromatic alcohol.

[0048] The present invention provides a jet loop system device, including one or more groups of the jet loop systems described in the above technical solutions.

[0049] As an embodiment of the present invention, the multiple sets of jet circulation systems may be 2 to 4 sets, may also be 2 to 3 sets, or may also be 2 sets. By setting multiple sets of jet circulation systems, the purity of the product can be further improved in the present invention.

[0050] In the present invention, when the jet circulation system device includes multiple sets of jet circulation systems, the multiple sets of jet circulation systems are connected in series; the connection mode is: the third discharge port of the hydrocyclone in the upper-stage jet circulation system is communicated with the first feed port of the reaction kettle in the lower-stage jet circulation system.

[0051] The present invention also provides a method for preparing an aromatic alcohol. Using the device described in the above technical solution, when the jet circulation system device includes a set of jet circulation systems, the method for preparing the aromatic alcohol includes: introducing a raw material and a catalyst into the reaction kettle through the first feed port to obtain a reaction solution; the liquid level of the reaction solution is higher than the bottom of the Venturi injector; closing the first valve, under the action of a circulation pump, the reaction solution enters the heat exchanger through the first discharge port and the second feed port for heating, and then enters the Venturi injector through the second discharge port. At the same time, hydrogen is introduced into the Venturi injector and reacts with the reaction solution entering the Venturi injector to be sprayed into the reaction kettle under the action of a cyclone to form a jet circulation for a reduction reaction; after the reduction reaction ends, the first valve is opened to enable the obtained product to enter the hydrocyclone for solid-liquid separation to obtain a liquid-phase product aromatic alcohol and a solid-phase catalyst; the liquid-phase product aromatic alcohol is discharged through the third discharge port to obtain the aromatic alcohol; the raw material is an aromatic ketone; the solid-phase catalyst enters the straight pipe section structure through the sand settling port, and then enters the reaction kettle through the catalyst feed port for recycling;

[0052] When the jet circulation system device includes multiple groups of jet circulation systems, the method for preparing the aromatic alcohol includes: feeding raw materials and a catalyst into a reaction kettle through a first feed port of a first-stage jet circulation system to obtain a reaction solution; opening a first valve, and under the action of a circulation pump, feeding the reaction solution into a heat exchanger through a first discharge port and a second feed port for heating, and then feeding the reaction solution into a hydrocyclone and a Venturi injector through a second discharge port. Meanwhile, hydrogen is fed into the Venturi injector, and the reaction solution entering the Venturi injector is ejected into the reaction kettle under the action of a cyclone together with the hydrogen to form a jet circulation for a reduction reaction; the reaction solution entering the hydrocyclone is subjected to solid-liquid separation in the hydrocyclone to obtain a liquid phase and a solid-phase catalyst; the obtained solid-phase catalyst enters a straight pipe section structure through a sand settling port, and then enters the reaction kettle through a catalyst feed port for recycling; the obtained liquid phase is discharged through a third discharge port, and is used as a raw material and a catalyst to be fed into the reaction kettle through a first feed port of a next-stage jet circulation system to obtain a reaction solution, and the operations in the first-stage jet circulation system are repeated to form a circulation for a reduction reaction; the last-stage jet circulation system adopts the same operations as a group of jet circulation systems of the jet circulation system device to obtain the aromatic alcohol; the liquid level of the reaction solution in each stage of the jet circulation system is higher than the bottom of the corresponding Venturi injector.

[0053] As an embodiment of the present invention, the aromatic ketone may be 4-isobutylacetophenone, acetophenone, p-methoxyacetophenone, α-arylacetone or benzophenone.

[0054] As an embodiment of the present invention, the feeding flow rate of the raw materials may be 0.04 - 0.06 m 3 / h, or may also be 0.05 m 3 / h.

[0055] As an embodiment of the present invention, the filling rate of the reaction solution in the reaction kettle in each stage of the jet circulation system may independently be 40 - 70%, or may also independently be 50 - 60%. Limiting the filling rate of the reaction solution in the reaction kettle in each stage of the jet circulation system within the above range in the present invention can improve the reaction efficiency of the whole system.

[0056] In the present invention, the addition amount of the catalyst in each stage of the jet circulation system is preferably independently 1 - 10% of the mass of the raw materials, more preferably independently 3 - 8%, and further preferably 5% on average. Setting the addition amount of the catalyst in each stage of the jet circulation system within the above range in the present invention can ensure that there is enough catalyst to catalyze the reaction and improve the reaction rate.

[0057] In the present invention, the injection velocity of the injection circulation in each stage of the injection circulation system is preferably independently 15 to 60 m / s, more preferably independently 20 to 40 m / s. As an embodiment of the present invention, the injection velocity of the injection circulation in each stage of the injection circulation system can also be independently 25 to 35 m / s, or can also be 30 m / s for all. If the injection velocity of the injection circulation in the present invention is too small, the suction volume will be relatively low and the reaction rate will decrease. If the velocity is too high, the energy consumption of the pump will be too high, which is not conducive to energy saving. By limiting the injection velocity of the injection circulation in each stage of the injection circulation system within the above range, the reaction rate can be increased in the present invention.

[0058] As an embodiment of the present invention, the flow rate of hydrogen gas introduced into the Venturi injector 5 can be 250 to 350 mL / min, or can also be 300 mL / min; the hydrogen gas can also be introduced into the reaction kettle 1 through the first gas inlet provided at the top of the reaction kettle 1. The present invention does not have a special limitation on the flow rate of hydrogen gas introduced into the reaction kettle 1, as long as the pressure in the reaction kettle can be maintained at 1.0 to 2.5 MPa.

[0059] As an embodiment of the present invention, when the injection circulation system device includes a group of injection circulation systems, the volume ratio of the circulation amount of the injection circulation in the injection circulation system to the volume of the raw material can be (20 to 100):1, or can also be (30 to 60):1, or can also be (40 to 50):1; when the injection circulation system device includes multiple groups of injection circulation systems, the volume ratio of the circulation amount of the injection circulation in the last stage of the injection circulation system to the volume of the raw material can be (20 to 100):1, or can also be (30 to 60):1, or can also be (40 to 50):1. As an embodiment of the present invention, the circulation velocity of the circulation pump in each stage of the injection circulation system can be independently 2 to 5 m 3 / h, or can also be independently 3 to 4 m 3 / h, or can also be 4 m for all 3 / h. By limiting the volume ratio of the circulation amount of the injection circulation in the injection circulation system to the volume of the raw material and the circulation velocity of the circulation pump within the above range, the materials can be better mixed and fully reacted, and the conversion rate of the raw material and the yield of the product can be increased in the present invention.

[0060] In the present invention, the temperature of the reduction reaction in each stage of the jet loop system is preferably independently 40 to 80 °C, more preferably independently 50 to 70 °C, further preferably independently 55 to 65 °C, and most preferably all 60 °C; the pressure of the reduction reaction in each stage of the jet loop system is preferably independently 1.0 to 2.5 MPa, more preferably independently 1.5 to 2.2 MPa, further preferably independently 1.6 to 1.8 MPa, and most preferably all 1.6 MPa. Limiting the temperature and pressure of the reduction reaction in each stage of the jet loop system within the above ranges in the present invention can ensure the smooth and sufficient progress of the reduction reaction, and improve the yield and purity of the product.

[0061] As an embodiment of the present invention, when the jet loop system device includes a set of jet loop systems, in the preparation process of the aromatic alcohol, the first valve V-4 is first closed. After the reduction reaction is completed, the third valve V-1, the fourth valve V-2, and the fifth valve V-5 are closed, and the second valve V-3 and the first valve V-4 are opened. The product of the reduction reaction enters the hydrocyclone for solid-liquid separation to obtain the liquid-phase product aromatic alcohol and the solid-phase catalyst. The liquid-phase product aromatic alcohol is exported through the third discharge port. After obtaining the aromatic alcohol, the third valve V-1 is opened to enable the solid-phase catalyst to enter the reaction kettle through the catalyst feed port for recycling, or the fourth valve V-2 is opened to recover the solid-phase catalyst.

[0062] As an embodiment of the present invention, when the jet loop system device includes multiple sets of jet loop systems, in the preparation process of the aromatic alcohol, the fourth valve V-2 is closed in the first stage and all intermediate stages of the jet loop system, and the third valve V-1, the second valve V-3, the first valve V-4, and the fifth valve V-5 are opened. The first valve V-4 is closed in the last stage of the jet loop system. The reaction liquid entering the hydrocyclone is subjected to solid-liquid separation in the hydrocyclone to obtain a liquid phase and a solid-phase catalyst. The solid-phase catalyst enters the straight pipe section structure through the sand settling port, and then enters the reaction kettle through the catalyst feed port for recycling. The liquid phase is exported through the third discharge port and used as a raw material to enter the reaction kettle through the first feed port of the next stage of the jet loop system together with the catalyst to obtain a reaction liquid, and the operation in the first stage of the jet loop system is repeated to form a circulation for the reduction reaction; after the reduction reaction in the last stage of the jet loop system is completed, the third valve V-1, the fourth valve V-2, and the fifth valve V-5 in the last stage of the jet loop system are closed, and the second valve V-3 and the first valve V-4 are opened. The product of the reduction reaction enters the hydrocyclone for solid-liquid separation to obtain the liquid-phase product aromatic alcohol and the solid-phase catalyst. The liquid-phase product aromatic alcohol is exported through the third discharge port. After obtaining the aromatic alcohol, the third valve V-1 is opened to enable the solid-phase catalyst to enter the reaction kettle through the catalyst feed port for recycling, or the fourth valve V-2 is opened to recover the solid-phase catalyst.

[0063] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0064] Embodiment 1

[0065] A jet loop system, as Figure 1 shown, is composed of a reaction kettle 1, a circulation pump 2, a heat exchanger 3, a hydrocyclone 4, a Venturi injector 5 and a cyclone 6;

[0066] A first feed inlet, a catalyst feed inlet and a jet feed inlet are respectively provided at the top of the reaction kettle 1; the jet feed inlet is provided with a Venturi injector 5, and the bottom of the Venturi injector 5 is inserted into the interior of the reaction kettle 1; a cyclone 6 is installed above the main nozzle of the Venturi injector 5;

[0067] The bottom of the reaction kettle 1 is conical; a first discharge port is provided at the bottom of the reaction kettle 1;

[0068] The bottom of the heat exchanger 3 is conical; a second feed inlet is provided at the bottom of the heat exchanger 3; the first discharge port is communicated with the second feed inlet through a circulation pump 2;

[0069] A second discharge port is provided at the top of the heat exchanger 3; the second discharge port is respectively communicated with the feed inlet of the hydrocyclone 4 and the feed inlet of the Venturi injector 5; a first valve V-4 is provided between the second discharge port and the feed inlet of the hydrocyclone 4; a fifth valve V-5 is provided between the second discharge port and the feed inlet of the Venturi injector 5;

[0070] A third discharge port is provided at the top of the hydrocyclone 4; a second valve V-3 is provided at the third discharge port; a sand settling port is provided at the bottom of the hydrocyclone 4, and the sand settling port is connected with a straight pipe section structure; the straight pipe section structure is communicated with the catalyst feed inlet; a third valve V-1 is provided between the straight pipe section structure and the circulation feed inlet; a solid discharge port is further provided on the straight pipe section structure; a fourth valve V-2 is provided at the solid discharge port;

[0071] The conical inclination angle of the bottom of the reaction kettle 1 is 60°; the conical inclination angle of the bottom of the heat exchanger 3 is 60°;

[0072] A first air inlet is further provided at the top of the reaction kettle 1;

[0073] The ratio of the diameter of the mixing section to the diameter of the nozzle in the Venturi injector 5 is 1.5:1; the aspect ratio of the mixing section in the Venturi injector 5 is 10;

[0074] The position where the bottom of the Venturi ejector 5 is inserted into the reactor 1 is calculated starting from the bottom of the cylindrical section of the reactor, and is located at 30% of the total height of the cylindrical section of the reactor.

[0075] Example 2

[0076] The difference between Example 2 and Example 1 is only that the position where the bottom of the Venturi ejector 5 is inserted into the reactor 1 is calculated starting from the bottom of the cylindrical section of the reactor, and is located at 45% of the total height of the cylindrical section of the reactor, and the others are the same as in Example 1.

[0077] Example 3

[0078] The difference between Example 3 and Example 1 is only that the position where the bottom of the Venturi ejector 5 is inserted into the reactor 1 is calculated starting from the bottom of the cylindrical section of the reactor, and is located at 15% of the total height of the cylindrical section of the reactor, and the others are the same as in Example 1.

[0079] Example 4

[0080] An injection circulating system device, such as Figure 1 shown, is composed of a group of injection circulating systems described in Example 1.

[0081] Example 5

[0082] An injection circulating system device, such as Figure 2 shown, is composed of two groups of injection circulating systems described in Example 1; among them, the first-stage injection circulating system is composed of a reactor 1, a circulation pump 2, a heat exchanger 3, a hydrocyclone 4, a Venturi ejector 5, and a cyclone 6, and the structure of the first-stage injection circulating system is the same as that of the injection circulating system described in Example 1; the second-stage injection circulating system is composed of a reactor 7, a circulation pump 8, a heat exchanger 9, a hydrocyclone 10, a Venturi ejector 11, and a cyclone 12, and the reactor 7 of the second-stage injection circulating system has the same structure as the reactor 1 in the injection circulating system described in Example 1, the circulation pump 8 has the same structure as the circulation pump 2 in the injection circulating system described in Example 1, the heat exchanger 9 has the same structure as the heat exchanger 3 in the injection circulating system described in Example 1, the hydrocyclone 10 has the same structure as the hydrocyclone 4 in the injection circulating system described in Example 1, the Venturi ejector 11 has the same structure as the Venturi ejector 5 in the injection circulating system described in Example 1, and the cyclone 12 has the same structure as the cyclone 6 in the injection circulating system described in Example 1;

[0083] The two groups of injection circulating systems are connected in series; the series connection method is: the third discharge port of the hydrocyclone in the upper-stage injection circulating system is communicated with the first feed port of the reactor in the lower-stage injection circulating system.

[0084] Example 6

[0085] An injection circulation system device, which is different from that of Embodiment 5 in that it is composed of two sets of injection circulation systems described in Embodiment 2;

[0086] The two sets of injection circulation systems are connected in series; the connection method is: the third discharge port of the hydrocyclone in the upper-stage injection circulation system is communicated with the first feed port of the reaction kettle in the lower-stage injection circulation system.

[0087] Embodiment 7

[0088] An injection circulation system device, which is different from that of Embodiment 5 in that it is composed of two sets of injection circulation systems described in Embodiment 3;

[0089] The two sets of injection circulation systems are connected in series; the connection method is: the third discharge port of the hydrocyclone in the upper-stage injection circulation system is communicated with the first feed port of the reaction kettle in the lower-stage injection circulation system.

[0090] Embodiment 8

[0091] A preparation method of 4-isobutylphenylethanol, using the device described in Embodiment 4, and the preparation method of 4-isobutylphenylethanol is as follows:

[0092] 150 kg of 4-isobutylacetophenone (60% of the total volume of Reactor 1) is fed into Reactor 1 through the first feed port at a flow rate of 0.05 m 3 / h and a catalyst (Raney nickel, 5% of the weight of 4-isobutylacetophenone) to obtain a reaction solution; the liquid level of the reaction solution is higher than the bottom of the venturi injector 5; the first valve V-4 is closed, and under the action of the circulation pump 2, the reaction solution enters the heat exchanger through the first discharge port and the second feed port for heating, and then enters the venturi injector 5 through the second discharge port. At the same time, hydrogen is introduced into Reactor 1 through the first gas feed port at the top of Reactor 1 at a flow rate of 300 mL / min and into the venturi injector 5 at a flow rate of 300 mL / min. The reaction solution entering the venturi injector 5 is sprayed into the reaction kettle under the action of the cyclone 6 to form an injection circulation (the injection speed of the injection circulation is 20 m / s, the volume ratio of the circulation amount to 4-isobutylacetophenone is 50:1, and the circulation speed of the circulation pump is 4 m 3 / h) to carry out a reduction reaction at 55 °C and 1.5 MPa; after the reduction reaction is completed, the first valve V-4 is opened to enable the obtained product to enter the hydrocyclone 4 for solid-liquid separation to obtain a liquid-phase product 4-isobutylphenylethanol and a solid-phase catalyst; the liquid-phase product 4-isobutylphenylethanol is discharged through the third discharge port to obtain 4-isobutylphenylethanol; the solid-phase catalyst enters the straight pipe section structure through the sand settling port, and then enters Reactor 1 through the catalyst feed port for recycling.

[0093] Example 9

[0094] A preparation method of 4-isobutylphenethyl alcohol, using the device described in Example 5. The preparation method of 4-isobutylphenethyl alcohol is as follows:

[0095] 150 kg of 4-isobutylacetophenone (60% of the total volume of Reactor 1) is fed into Reactor 1 through the first feed port of the first-stage jet-loop system at a flow rate of 0.05 m 3 / h and a catalyst (Raney nickel, 5% of the weight of 4-isobutylacetophenone) to obtain a reaction solution; the first-stage jet-loop system closes the fourth valve V-2, opens the third valve V-1, the second valve V-3 and the first valve V-4. Under the action of the circulation pump 2, the reaction solution enters the heat exchanger 3 through the first discharge port and the second feed port for heating, and then enters the hydrocyclone 4 and the Venturi injector 5 through the second discharge port. At the same time, hydrogen is introduced into the Venturi injector 5 and sprayed into Reactor 1 together with the reaction solution entering the Venturi injector 5 under the action of the cyclone 6 to form a jet-loop (the jet speed of the jet-loop is 20 m / s, the volume ratio of the circulation volume to 4-isobutylacetophenone is 50:1, and the circulation speed of the circulation pump is 4 m 3 / h). A reduction reaction is carried out at 60 °C and 1.6 MPa; the reaction solution entering the hydrocyclone is subjected to solid-liquid separation in the hydrocyclone to obtain a liquid phase and a solid-phase catalyst. The solid-phase catalyst enters the straight pipe section structure through the sand settling port, and then enters Reactor 1 through the catalyst feed port for recycling. The liquid phase is exported through the third discharge port and used as a raw material to enter Reactor 7 through the first feed port of the second-stage jet-loop system together with the catalyst to obtain a reaction solution; the second-stage jet-loop system closes the first valve V-8. Under the action of the circulation pump 8, the reaction solution enters the heat exchanger 9 through the first discharge port and the second feed port for heating, and then enters the Venturi injector 11 through the second discharge port. At the same time, hydrogen is introduced into Reactor 7 through the first gas feed port at the top of Reactor 7 at a flow rate of 300 mL / min and into the Venturi injector 11 at a flow rate of 300 mL / min. It is sprayed into Reactor 7 together with the reaction solution entering the Venturi injector 11 under the action of the cyclone 12 to form a jet-loop (the jet speed of the jet-loop is 20 m / s, the volume ratio of the circulation volume to 4-isobutylacetophenone is 50:1, and the circulation speed of the circulation pump is 4 m 3 / h) The reduction reaction is carried out at 60 °C and 1.6 MPa; after the reduction reaction is completed, the first valve V-8 is opened to allow the obtained product to enter the hydrocyclone 10 for solid-liquid separation to obtain the liquid-phase product 4-isobutylphenethyl alcohol and the solid-phase catalyst; the liquid-phase product 4-isobutylphenethyl alcohol is discharged through the third discharge port to obtain 4-isobutylphenethyl alcohol; the solid-phase catalyst enters the straight pipe section structure through the sand settling port and then enters the reaction kettle 7 through the catalyst feed port for recycling; the liquid level of the reaction liquid in each stage of the jet circulation system is higher than the bottom of the corresponding Venturi injector.

[0096] Example 10

[0097] The difference between Example 10 and Example 9 is that the device described in Example 6 is used, and the others are the same as Example 9.

[0098] Example 11

[0099] The difference between Example 11 and Example 9 is that the device described in Example 7 is used, and the others are the same as Example 9.

[0100] Example 12

[0101] The difference between Example 12 and Example 9 is that the circulation speed of the circulation pump is 2 m 3 / h, and the others are the same as Example 9.

[0102] Example 13

[0103] The difference between Example 13 and Example 9 is that the circulation speed of the circulation pump is 3 m 3 / h, and the others are the same as Example 9.

[0104] Example 14

[0105] The difference between Example 14 and Example 9 is that the temperature of the reduction reaction is 45 °C, and the others are the same as Example 9.

[0106] Example 15

[0107] The difference between Example 15 and Example 9 is that the temperature of the reduction reaction is 75 °C, and the others are the same as Example 9.

[0108] Example 16

[0109] The difference between Example 16 and Example 9 is that the pressure of the reduction reaction is 1.2 MPa, and the others are the same as Example 9.

[0110] Example 17

[0111] The difference between Example 17 and Example 9 is that the pressure of the reduction reaction is 1.4 MPa, and the others are the same as Example 9.

[0112] Example 18

[0113] The difference between Example 18 and Example 9 is that the addition amount of the catalyst is 4% of the weight of 4-isobutylacetophenone, and the others are the same as in Example 9.

[0114] Example 19

[0115] The difference between Example 19 and Example 9 is that the addition amount of the catalyst is 6% of the weight of 4-isobutylacetophenone, and the others are the same as in Example 9.

[0116] The conversion rate of 4-isobutylacetophenone (IBAP), the yield of 4-isobutylethylbenzene alcohol (IBPE), and the yield of by-product 1-ethyl-4-isobutylbenzene (IBEB) in the preparation methods of Examples 8 - 19 were tested and analyzed using a gas chromatograph, and the obtained data are shown in Table 1.

[0117] Table 1 Data of the conversion rate of 4-isobutylacetophenone (IBAP), the yield of 4-isobutylethylbenzene alcohol (IBPE), and the yield of 4-isobutylphenylethylbenzene (IBEB) in the preparation methods of Examples 8 - 19

[0118] Example IBAP conversion rate / % IBPE yield / % IBEB yield / % 8 99.35 97.18 0.29 9 99.8 97.6 0.41 10 78.3 76.2 0.63 11 91.5 88.6 1.2 12 83.1 81.3 0.49 13 93.2 91.4 0.39 14 81.7 80.3 0.28 15 99.7 93.2 5.68 16 90.5 88.7 0.71 17 93.7 92.5 0.34 18 87.3 85.1 0.59 19 99.7 93.8 4.63

[0119] As can be seen from Table 1, the data of Examples 9 - 11 show that when the position where the Venturi ejector 5 is inserted into the interior of the reaction kettle 1 is calculated starting from the bottom of the cylindrical section of the reaction kettle and is located at 30% of the total height of the cylindrical section of the reaction kettle, and the raw material is 60% of the total volume of the reaction kettle 1, the IBAP conversion rate and the IBPE yield are the best. This is because if the insertion is too deep or too shallow, the gas holdup in the reaction kettle is too low, reducing the contact area of the gas-liquid-solid three-phase and lowering the reaction rate;

[0120] The data of Example 9, Example 12, and Example 13 show that the greater the circulation speed of the circulation pump, the higher the IBAP conversion rate and the IBPE yield. Because the greater the circulation speed of the circulation pump, the higher the flow rate of the material at the ejector outlet, the greater the gas holdup in the reaction kettle, and the faster the reaction rate;

[0121] The data of Example 9, Example 14, and Example 15 show that the optimal reduction reaction temperature is 60 °C. When the temperature is low, the IBAP conversion rate is low; when the temperature is high, the concentration of by-product IBEB is too high. This is because as the reaction temperature increases, the IBAP conversion rate increases, but at the same time, the formation rate of by-product IBEB accelerates.

[0122] The data of Example 9, Example 16, and Example 17 show that the higher the reduction reaction pressure, the higher the IBAP conversion rate and the IBPE yield. This is because the greater the pressure, the higher the hydrogen concentration, and the faster the reaction rate.

[0123] The data of Example 9, Example 18 and Example 19 show that the optimal catalyst mass content is 5%. When the catalyst content is low, the conversion rate of IBAP is low; when the catalyst concentration is high, the concentration of by-product IBEB is too high.

[0124] Using the device provided by the present invention to prepare aromatic alcohols can recycle the catalyst, and the conversion rate of aromatic ketones can be as high as 99.8%, the yield of aromatic alcohols can reach 97.5%, and the yield of by-products can be as low as below 0.5%. It has high raw material conversion rate, product yield and purity.

[0125] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A jet circulation system, comprising a reactor (1), a circulation pump (2), a heat exchanger (3), a hydrocyclone (4), a venturi ejector (5) and a cyclone (6); The top of the reactor (1) is respectively provided with a first feed port, a catalyst feed port and a jet feed port; the jet feed port is provided with a venturi injector (5), the bottom of the venturi injector (5) is inserted into the interior of the reactor (1); a swirler (6) is installed on the upper part of the mainstream nozzle of the venturi injector (5); The bottom of the reaction kettle (1) is conical; the bottom of the reaction kettle (1) is provided with a first discharge port; The bottom of the heat exchanger (3) is conical; a second feed port is provided at the bottom of the heat exchanger (3); the first discharge port and the second feed port are connected via a circulation pump (2); A second discharge port is provided at the top of the heat exchanger (3); the second discharge port is respectively connected to the feed port of the hydrocyclone (4) and the feed port of the venturi ejector (5); a first valve (V-4) is provided between the second discharge port and the feed port of the hydrocyclone (4); The top of the hydrocyclone (4) is provided with a third discharge port; the bottom of the hydrocyclone (4) is provided with a sand settling port, the sand settling port is connected to a straight pipe section structure; the straight pipe section structure is connected to the catalyst feed port.

2. The jet circulation system according to claim 1, characterized in that: The conical inclination angles of the bottoms of the reactor (1) and the heat exchanger (3) are independently 45 to 70 degrees.

3. The jet circulation system according to claim 1, characterized in that: The ratio of the diameter of the mixing section to the diameter of the nozzle in the Venturi ejector (5) is (1.5-3):1; The length-to-diameter ratio of the mixing section in the Venturi ejector (5) is 8-15.

4. A jet circulation system device, characterized in that: A jet circulation system comprising one or more groups of the jet circulation systems according to any one of claims 1 to 3; When the jet circulation system device includes multiple sets of jet circulation systems, the multiple sets of jet circulation systems are connected in series; The series connection mode is that the third discharge port of the hydrocyclone in the upper-stage jet circulation system is connected with the first feed port of the reactor in the lower-stage jet circulation system.

5. A method for preparing aromatic alcohol, using the device according to claim 4, when the jet circulation system device comprises a set of jet circulation systems, the method for preparing aromatic alcohol comprises: Feeding the raw materials and the catalyst into the reaction kettle through the first feed port to obtain a reaction solution; The liquid level of the reaction liquid is higher than the bottom of the venturi ejector; Close the first valve, and under the action of the circulation pump, allow the reaction liquid to enter the heat exchanger through the first discharge port and the second feed port for heating, and then enter the venturi ejector through the second discharge port, and at the same time, allow hydrogen to pass into the venturi ejector and, together with the reaction liquid entering the venturi ejector, be ejected into the reactor under the action of the cyclone to form a jet circulation for reduction reaction; After the reduction reaction is completed, the first valve is opened to allow the obtained product to enter the hydrocyclone for solid-liquid separation to obtain a liquid phase product, aromatic alcohol, and a solid phase catalyst; the liquid phase product, aromatic alcohol, is discharged through the third discharge port to obtain aromatic alcohol; the raw material is aromatic ketone; the solid phase catalyst enters the straight pipe section structure through the sand settling port, and then enters the reactor through the catalyst feed port for recycling; When the jet circulation system device includes multiple jet circulation systems, the preparation method of the aromatic alcohol includes: introducing the raw materials and the catalyst into the reactor through the first feed port of the first-stage jet circulation system to obtain a reaction liquid; opening the first valve, and under the action of a circulation pump, the reaction liquid enters the heat exchanger through the first discharge port and the second feed port for heating, and then enters the hydrocyclone and the venturi injector respectively through the second discharge port, and at the same time, hydrogen is introduced into the venturi injector and sprayed into the reactor together with the reaction liquid entering the venturi injector under the action of the cyclone to form a jet circulation for reduction reaction; the reaction liquid entering the hydrocyclone Solid-liquid separation is carried out in a hydrocyclone to obtain a liquid phase and a solid phase catalyst; the obtained solid phase catalyst enters a straight pipe section structure through a sand settling port, and then enters a reactor through a catalyst feed port for recycling; the obtained liquid phase is discharged through a third discharge port, and is introduced into a reactor as a raw material and a catalyst through a first feed port of a next-stage jet circulation system to obtain a reaction liquid, and the operation in the first-stage jet circulation system is repeated to form a circulation for reduction reaction; the last-stage jet circulation system adopts the same operation as the jet circulation system device as a group of jet circulation systems to obtain aromatic alcohol; the liquid level of the reaction liquid in each stage of the jet circulation system is higher than the bottom of the corresponding venturi injector.

6. The preparation method according to claim 5, characterized in that: The amount of catalyst added to each stage of the injection circulation system is independently 1-10% of the mass of the raw material.

7. The preparation method according to claim 4, characterized in that: The jet velocity of the jet circulation in each stage of the jet circulation system is independently 15 to 60 m / s.

8. The preparation method according to claim 4, characterized in that: When the jet circulation system device includes a set of jet circulation systems, the volume ratio of the circulation volume of the jet circulation in the jet circulation system to the raw material is (20-100):1; When the jet circulation system device includes multiple sets of jet circulation systems, the volume ratio of the circulation amount of the jet circulation in the last stage of the jet circulation system to the raw material is (20-100):

1.

9. The preparation method according to claim 4, characterized in that: The temperature of the reduction reaction in each stage of the jet circulation system is independently 40-80° C., and the pressure of the reduction reaction is independently 1.0-2.5 MPa.

10. The preparation method according to claim 4, characterized in that: The filling rate of the reaction liquid in the reaction kettle in each stage of the jet circulation system is independently 40-70%.

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