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CN118949905A - Method and device for producing isophorone by folding reactor - Google Patents

Method and device for producing isophorone by folding reactor Download PDF

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Publication number
CN118949905A
CN118949905A CN202411016739.1A CN202411016739A CN118949905A CN 118949905 A CN118949905 A CN 118949905A CN 202411016739 A CN202411016739 A CN 202411016739A CN 118949905 A CN118949905 A CN 118949905A
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China
Prior art keywords
reaction
cavity
liquid
chamber
transition
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CN202411016739.1A
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Chinese (zh)
Inventor
齐鹏宇
王盛文
毛建拥
胡鹏翔
王会
杜倩倩
王启刚
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Shandong Nhu Vitamin Co ltd
Zhejiang NHU Co Ltd
Shandong Xinhecheng Fine Chemical Technology Co Ltd
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Shandong Nhu Vitamin Co ltd
Zhejiang NHU Co Ltd
Shandong Xinhecheng Fine Chemical Technology Co Ltd
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Application filed by Shandong Nhu Vitamin Co ltd, Zhejiang NHU Co Ltd, Shandong Xinhecheng Fine Chemical Technology Co Ltd filed Critical Shandong Nhu Vitamin Co ltd
Publication of CN118949905A publication Critical patent/CN118949905A/en
Pending legal-status Critical Current

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Abstract

The invention relates to a method and a device for producing isophorone by a folding reactor. The reactor comprises a reaction tube and a reaction cavity to form a folding reactor, wherein reaction liquid firstly reacts in the reaction tube, then folds back to the outer reaction cavity to continue reaction, meanwhile, noncondensable gas generated in a reaction system is separated through a first exhaust port in the reaction stage of the reaction tube, noncondensable gas generated in the reaction system is also separated through a second exhaust port in the reaction stage of the reaction cavity, and only one layer of tube wall is arranged between the reaction tube and the reaction cavity, so that full heat exchange can be performed. The method comprises the steps of enabling the reaction liquid to sequentially flow through a reaction tube, a second transition cavity and a reaction cavity to carry out condensation reaction, and enabling the reaction liquid to be exhausted through a first exhaust port and a second exhaust port. In the method, the acetone single pass conversion rate and the isophorone effective selectivity are both higher, the reaction condition is milder, and the equipment energy consumption is low.

Description

Method and device for producing isophorone by folding reactor
Technical Field
The invention particularly relates to a method and a device for producing isophorone by a folding reactor.
Background
Alpha-isophorone (3, 5-trimethyl-2-cyclohexen-1-one) is an important chemical product. The high-molecular-weight resin has strong dissolving capacity and good dispersion and leveling property, and is an excellent solvent for a plurality of high-molecular resins; meanwhile, the synthetic material is also an important fine chemical synthetic raw material, and can be used for synthesizing fine chemical products such as 3, 5-dimethylphenol, tea-flavor ketone and the like.
Isophorone is industrially produced mainly by the acetone condensation process. The method for preparing isophorone by acetone condensation can be divided into two types according to the contact state of reactants: one is a compression method of pressurizing liquid in an alkaline solution; the other is a vapor phase catalytic condensation process of gaseous acetone on the surface of a solid catalyst. The gas phase condensation method generally adopts solid acid/alkali as a catalyst, other impurities are easy to generate in the gas phase condensation method, so that the conversion rate of the alpha-isophorone is low, the solid catalyst is easy to poison and deactivate, and the industrialized cost and difficulty are increased. The liquid phase method process is an internationally mainstream industrial production method, and the liquid phase condensation method uses liquid acid/alkali as a catalyst, and the catalyst is easy to prepare, but because the condensation reaction is a typical continuous and parallel complex reaction network, more byproducts are generated, the selectivity of a target product isophorone is lower, and the single pass conversion rate of acetone is greatly limited in industry. Meanwhile, under the reaction condition, double liquid phases exist in the system and gas phase entrainment exists, so that high requirements are put forward on the mixing of the reaction liquid, the control of a flow field and the control of the product yield.
GB583863 takes 25% NaOH solution as a catalyst, a kettle reactor with strong stirring is adopted, reactants are fully contacted through the strong stirring effect, the reaction is carried out for 37 minutes at 170 ℃, the acetone conversion rate is 13.6%, the alpha-isophorone selectivity is 51%, but the acetone conversion rate and the alpha-isophorone selectivity of the process are still lower.
US3981918 discloses a process for preparing a-isophorone by reactive distillation. The reaction and the rectification are integrated into one reaction rectifying tower, the stirring effect is realized by utilizing the disturbance of gas phase, the acetone conversion rate is 10.4%, the alpha-isophorone selectivity is 82%, but the process has the defects that the residence time of reactants is not easy to control accurately, and the single pass conversion rate of the acetone is low; the internal structure of the tower is complex, the equipment investment is high, and meanwhile, a high equipment control level is required.
CN102516051B adopts a mixer and a microchannel reactor, the mass and heat transfer effect is good, the mass fraction of isophorone is 91.3%, the single pass conversion rate of acetone is 22.7%, but the acetone conversion rate of the process is still not ideal.
CN101633610a discloses a process for preparing isophorone by supercritical method. The acetone and the catalyst solution are subjected to supercritical reaction in a tubular reactor under the conditions of high pressure of 8.0-20.0MPa and high temperature of 280-320 ℃, the reaction liquid is decompressed and enters a flash tower, unreacted acetone mixture is recovered from the top of the flash tower, and the tower bottom liquid enters a hydrolysis tower to hydrolyze polymers (C12 and C15) in the acetone mixture. The process has high acetone converting rate and high reaction selectivity, but utilizes supercritical condition to realize homogeneous reaction, and has harsh condition, high equipment investment and high power consumption. And the high temperature accelerates the degree and the rate of side reactions, which is unfavorable for the control of the reactions.
Disclosure of Invention
The invention aims to provide a method for producing isophorone, which adopts an acetone liquid phase condensation method, has higher acetone single pass conversion rate and isophorone effective selectivity, and has milder reaction conditions and low equipment energy consumption.
The invention also aims to provide a production device for the method for producing isophorone, by adopting the production device, when isophorone is synthesized by an acetone liquid phase condensation method, the equipment cost and the energy consumption are low, and the single pass conversion rate of acetone and the effective selectivity of isophorone can be improved.
In order to achieve the above purpose, the invention adopts the following technical scheme:
A process for producing isophorone by subjecting acetone in a liquid phase to a condensation reaction in the presence of a catalyst solution to produce isophorone, the condensation reaction being carried out in a condensation reaction vessel comprising a reaction tube, a reaction chamber, a first transition chamber and a second transition chamber;
The inlet of the reaction tube is communicated with the first transition cavity, and the outlet of the reaction tube is communicated with the second transition cavity;
At least part of the reaction tube is positioned in the reaction cavity, and the reaction liquid in the reaction tube exchanges heat with the reaction liquid in the reaction cavity;
The first transition chamber is provided with a liquid inlet, the second transition chamber is provided with a first exhaust port and a liquid outlet, and the reaction chamber is provided with a liquid inlet, a liquid outlet and a second exhaust port;
The liquid outlet of the second transition cavity is connected with the liquid inlet of the reaction cavity, so that the reaction liquid enters the first transition cavity from the liquid inlet of the first transition cavity, flows through the reaction tube to sequentially enter the second transition cavity, and then enters the reaction cavity through the liquid outlet of the second transition cavity and the liquid inlet of the reaction cavity;
the method comprises the steps of enabling the reaction liquid to sequentially flow through the reaction tube, the second transition cavity and the reaction cavity to carry out condensation reaction, and enabling the reaction liquid to be exhausted through the first exhaust port and the second exhaust port.
In the prior art, the liquid phase process for preparing the alpha-isophorone by taking the acetone as the raw material has the problems of uneven mixing among phases, poor mass transfer effect, high difficulty in reaction process control, high post-reaction treatment capacity, high energy consumption and running cost and the like in production. The inventor of the application discovers through research that by forming a reaction tube and a reaction cavity into a folding reactor, the reaction liquid firstly reacts in the reaction tube, then folds back to the outer reaction cavity to continue the reaction, meanwhile, the noncondensable gas generated in the reaction system is separated through a first exhaust port in the reaction stage of the reaction tube, and the noncondensable gas generated in the reaction system is also separated through a second exhaust port in the reaction stage of the reaction cavity, so that the mass transfer effect can be enhanced, the influence of the noncondensable gas generated in the reaction system on the acetone conversion rate and the alpha-isophorone reaction selectivity can be reduced, and the conversion rate and the reaction selectivity of the condensation reaction can be further improved. In addition, the acetone condensation reaction is exothermic, and the concentration of the reaction substrate is relatively high in the inner process of the condensation reaction kettle, namely the reaction tube, so that the reaction is accelerated along with the exothermic reaction, and the reaction materials have the tendency of temperature rise in the inner process. Meanwhile, as the reaction proceeds, after materials enter the outer course of the reactor, namely the reaction cavity, the concentration of raw material substrates in the reactor is gradually reduced, the reaction is slowed down, the heat release amount is gradually reduced, the heat release amount of the whole reactor is mainly concentrated in the outer course, the outer course temperature is gradually reduced under the condition of no heat source, the heat generated in the inner course reaction process can provide a heat source for the outer course, the materials of the outer course can cool the inner Cheng Wuliao, only one layer of reaction tube is arranged between the inner course and the outer course, and the heat exchange efficiency is high. The folding type reactor partition wall coupling heat exchange mode can maintain the reaction temperature of the system, can stably control the whole reaction, does not need an external heat source in the reaction process of the system, and can effectively solve the problems of large heat dissipation capacity and high post-treatment energy consumption of the traditional tubular reactor and tower type rectification reactor.
The non-condensable gases generated in the reaction system and required to be exhausted through the first exhaust port and the second exhaust port mainly comprise the following substances: 1) The byproduct methane is generated by a target product isophorone cracking isomerization process under high temperature conditions; 2) A byproduct ketene, which is produced by acetone as a reaction raw material under high temperature conditions; 3) The nitrogen, raw material acetone is extremely inflammable liquid, the flash point is low, and the raw material storage is usually protected by adopting nitrogen atmosphere, so that certain nitrogen exists in a feed liquid phase, the solubility of the nitrogen is reduced after the temperature is raised, and non-condensable gas nitrogen is generated.
The above-mentioned several non-condensable gases are all gaseous under the reaction condition, and the interior of condensation reaction kettle is normally liquid-liquid mass transfer, and the gas is existed in the system, so that it can affect liquid-liquid mass transfer process and further can affect reaction conversion rate. The production process of pyrolysis accessory substance is mostly endothermic process, can consume system's heat and noncondensable gas heat transfer coefficient is less than liquid, and can't carry out heat transfer through the phase change heat, can influence the system heat transfer. The generation of gaseous byproducts, if not removed from the reaction system, can promote more side reactions, affecting yield and selectivity. In addition, for continuous devices, such as a reaction system in which non-condensable gas is not discharged for a long time, the non-condensable gas gradually occupies the space of the reaction system, which is equivalent to the reduction of the liquid phase space of the reaction system, the residence time is shortened, and the reaction conversion rate is affected. According to the invention, the first exhaust port and the second exhaust port are arranged to timely discharge the noncondensable gas in the reaction system such as the reaction tube and the reaction cavity out of the reaction system, so that the conversion rate and the reaction selectivity of acetone can be improved.
In some embodiments, a plurality of baffles for changing the flowing direction of the reaction liquid are arranged in the reaction cavity at intervals, and the baffles are arranged in a staggered and opposite mode.
In some embodiments, the reaction chamber comprises a partition, an upper chamber, and a lower chamber, the partition for isolating the upper chamber and the lower chamber; the reaction liquid flows through the upper chamber and the lower chamber from the liquid inlet of the reaction chamber and flows out from the liquid outlet of the reaction chamber; a plurality of baffles used for changing the flowing direction of the reaction liquid are arranged in the upper chamber and the lower chamber at intervals, and the baffles are arranged in a staggered and opposite mode. Multiple baffles may enhance the mixing effect and further promote the reaction.
In some embodiments, the upper chamber and the lower chamber are provided with 4 to 1000 baffles in total.
In some embodiments, two adjacent baffles in the upper chamber are disposed on the upper wall and the partition, respectively, of the upper chamber and two adjacent baffles in the lower chamber are disposed on the lower wall and the partition, respectively, of the lower chamber.
In some embodiments, the heights of the upper chamber and the lower chamber are the same, and the heights of the plurality of baffles of the upper chamber and the lower chamber are the same.
In some embodiments, the height of the plurality of baffles of the upper chamber is 20% to 80% of the height of the upper chamber; the height of the baffles of the lower chamber is 20% -80% of the height of the lower chamber.
In some embodiments, the second transition chamber is located above the first transition chamber; the first exhaust port is positioned at the upper part of the second transition cavity; the second exhaust port is positioned at the upper part of the reaction cavity.
In some embodiments, the condensation reaction vessel is a horizontal reaction vessel, the liquid inlet of the reaction chamber is located at the front end of the reaction chamber, and the second exhaust port is located at the upper portion of the rear end of the reaction chamber.
In some embodiments, the length of the barrel of the horizontal reaction kettle is 3000-50000 mm, and the diameter is 300-5000 mm.
In the invention, the front and the rear are defined according to the flow sequence of the reaction liquid, the flowing direction of the reaction liquid is the front end, and the flowing direction of the reaction liquid is the rear end.
In some embodiments, the reaction tube is a U-shaped reaction tube.
In some embodiments, the condensation reaction vessel further comprises a support plate for supporting the reaction tube, the support plate being fixedly connected to the vessel wall of the condensation reaction vessel.
In some embodiments, the plane of the support plate is a vertical plane, and the support plate is provided with a through hole for the reaction tube to pass through.
In some embodiments, the number of reaction tubes is 1 to 1000. When the number of the reaction tubes is large, the reaction tubes may be tube bundles. The feeding and reaction are carried out in parallel between the different bundles.
In some embodiments, the tube diameter of the reaction tube is 8 to 60mm.
In some embodiments, the method further comprises the step of mixing the acetone and the catalyst solution in a mixer to obtain the reaction solution.
In some embodiments, the mixer is a static mixer.
In some embodiments, the method further comprises the step of preheating the acetone and catalyst solution.
In some embodiments, the method further comprises condensing the gas exiting the first and second vents prior to the step of gas-liquid separation. The condensation may be carried out in, for example, a condenser. The gas-liquid separation may be performed, for example, in a gas-liquid separation tank.
In some embodiments, the method further comprises the step of rectifying the reaction solution after the condensation reaction. The liquid phase after gas-liquid separation and the reaction liquid enter a subsequent rectification treatment system together for separation, which is beneficial to the recovery of isophorone entrained by gas phase.
In some embodiments, the temperature of the reaction solution as it enters the reactor is 120 to 220 ℃, preferably 130 to 190 ℃.
In some embodiments, the condensation reaction is carried out at a pressure of 0.5 to 10MPa, preferably 2.0 to 3.0 MPa.
In some embodiments, the reaction solution has a feed mass flow rate of 5 to 3000kg/min, preferably 10 to 50kg/min.
In some embodiments, the mass ratio of catalyst to acetone in the catalyst solution is from 0.0001 to 0.01:1, preferably from 0.0004 to 0.001:1. The catalyst solution is NaOH solution, etc.
In some embodiments, the mass concentration of the catalyst solution is 1% to 30%; preferably 3% to 5%.
The invention also provides a production device for the method for producing isophorone, which comprises a mixer and a condensation reaction kettle which are connected in sequence;
the mixer is used for mixing acetone and a catalyst solution to obtain a reaction solution;
the condensation reaction kettle comprises a reaction tube, a reaction cavity, a first transition cavity and a second transition cavity;
The inlet of the reaction tube is communicated with the first transition cavity, and the outlet of the reaction tube is communicated with the second transition cavity;
At least part of the reaction tube is positioned in the reaction cavity, and the reaction liquid in the reaction tube exchanges heat with the reaction liquid in the reaction cavity;
The first transition chamber is provided with a liquid inlet, the second transition chamber is provided with a first exhaust port and a liquid outlet, and the reaction chamber is provided with a liquid inlet, a liquid outlet and a second exhaust port;
The liquid outlet of the second transition cavity is connected with the liquid inlet of the reaction cavity, so that the reaction liquid enters the first transition cavity from the liquid inlet of the first transition cavity, flows through the reaction tube to sequentially enter the second transition cavity, and then enters the reaction cavity through the liquid outlet of the second transition cavity and the liquid inlet of the reaction cavity;
the first exhaust port and the second exhaust port are used for exhausting the reaction liquid.
In some embodiments, a plurality of baffles for changing the flowing direction of the reaction liquid are arranged in the reaction cavity at intervals, and the baffles are arranged in a staggered and opposite mode.
In some embodiments, the reaction chamber comprises a partition, an upper chamber, and a lower chamber, the partition for isolating the upper chamber and the lower chamber; the reaction liquid flows through the upper chamber and the lower chamber from the liquid inlet of the reaction chamber and flows out from the liquid outlet of the reaction chamber; a plurality of baffles used for changing the flowing direction of the reaction liquid are arranged in the upper chamber and the lower chamber at intervals, and the baffles are arranged in a staggered and opposite mode.
In some embodiments, the upper chamber and the lower chamber are provided with 4 to 1000 baffles in total.
In some embodiments, two adjacent baffles in the upper chamber are disposed on the upper wall and the partition, respectively, of the upper chamber and two adjacent baffles in the lower chamber are disposed on the lower wall and the partition, respectively, of the lower chamber.
In some embodiments, the heights of the upper chamber and the lower chamber are the same, and the heights of the plurality of baffles of the upper chamber and the lower chamber are the same.
In some embodiments, the height of the plurality of baffles of the upper chamber is 20% to 80% of the height of the upper chamber; the height of the baffles of the lower chamber is 20% -80% of the height of the lower chamber.
In some embodiments, the second transition chamber is located above the first transition chamber; the first exhaust port is positioned at the upper part of the second transition cavity; the second exhaust port is positioned at the upper part of the reaction cavity.
In some embodiments, the condensation reaction vessel is a horizontal reaction vessel, the liquid inlet of the reaction chamber is located at one end of the reaction chamber, and the second exhaust port is located at an upper portion of the other end of the reaction chamber.
In some embodiments, the length of the barrel of the horizontal reaction kettle is 3000-50000 mm, and the diameter is 300-5000 mm.
In some embodiments, the reaction tube is a U-shaped reaction tube.
In some embodiments, the condensation reaction vessel further comprises a support plate for supporting the reaction tube, the support plate being fixedly connected to the vessel wall of the condensation reaction vessel.
In some embodiments, the plane of the support plate is a vertical plane, and the support plate is provided with a through hole for the reaction tube to pass through.
In some embodiments, the number of reaction tubes is 1 to 1000.
In some embodiments, the tube diameter of the reaction tube is 8 to 60mm.
In some embodiments, the mixer is a static mixer.
In some embodiments, the production apparatus further comprises an acetone storage tank and a catalyst solution storage tank.
In some embodiments, the production apparatus further comprises an acetone preheater located between the acetone storage tank and the mixer.
In some embodiments, the production apparatus further comprises a catalyst solution preheater located between the catalyst solution storage tank and the mixer.
In some embodiments, the production apparatus further comprises a gas-liquid separation tank located at the rear end of the condensation reaction vessel.
In some embodiments, the production apparatus further comprises a condenser located between the condensation reaction vessel and the vapor-liquid separation tank.
Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages:
According to the invention, through developing the folding condensation reaction kettle, gas-liquid separation in the reaction process is realized by arranging the first exhaust port and the second exhaust port, non-condensable gas influencing the product quality is separated, the mass transfer effect is enhanced, the reaction yield and the product quality are improved, and the acetone conversion rate and the reaction selectivity are improved; meanwhile, the multi-layer folding reactor can effectively solve the problems of large heat dissipation capacity and high post-treatment energy consumption of the traditional tubular reactor and the tower rectifying reactor through self-coupling heat exchange of the reaction tube and the reaction cavity and almost no heat source.
According to the application, the first exhaust port and the second exhaust port are arranged to timely discharge the noncondensable gas in the reaction system such as the reaction tube and the reaction cavity out of the reaction system, so that the conversion rate and the reaction selectivity of acetone can be improved. The conversion rate of the application reaches more than 37%, and the reaction selectivity can reach more than 85%.
Drawings
FIG. 1 is a schematic view of a production apparatus for a process for producing isophorone in an embodiment of the present invention;
FIG. 2 is a schematic flow diagram of a reaction solution in a condensation reactor according to an embodiment of the present invention;
FIG. 3 is a schematic flow diagram of a reaction solution in a reaction chamber of a condensation reactor according to an embodiment of the present invention;
wherein, 1, an acetone storage tank; 2. a catalyst solution storage tank; 3. a catalyst solution preheater; 4. an acetone preheater; 5. a catalyst solution feed pump; 6. an acetone feed pump; 7. a mixer; 8. a condensation reaction kettle; 9. a condenser; 10. a gas-liquid separation tank; 11. a reaction tube; 12. a reaction chamber; 13. a first transition chamber; 14. a second transition chamber; 15. a liquid inlet; 16. a first exhaust port; 17. a liquid outlet; 18. a second exhaust port; 19-a baffle; 20. a partition plate; 21. an upper chamber; 22-a lower chamber; 23. and a support plate.
Detailed Description
In the present invention, "front end" and "rear end" are defined in terms of the flow order of the reaction liquid, and the direction in which the reaction liquid flows first is the front end and the direction in which the reaction liquid flows later is the rear end.
The production device of the invention can be embodied as follows:
As shown in fig. 1, the production apparatus includes an acetone storage tank 1 for recovering acetone and a mixing buffer tank for replenishing fresh acetone, a catalyst solution storage tank 2 for storing a catalyst solution, and a catalyst solution preheater 3 and an acetone preheater 4, and the catalyst solution and the acetone are preheated by the catalyst solution preheater 3 and the acetone preheater 4, respectively. The production device also comprises a catalyst solution feeding pump 5 and an acetone feeding pump 6, and acetone and the catalyst solution are mixed together through the two pumps and then enter a condensation reaction kettle 8 after passing through a static mixer 7.
As shown in fig. 2, the condensation reaction kettle 8 is formed by an inner process and an outer process, wherein the inner process is a reaction tube 11, for example, a folding U-shaped tube bundle, and is provided with a first transition cavity 13 and a second transition cavity 14, a liquid inlet 15 is arranged in the first transition cavity 13, and a liquid outlet 15 and a first exhaust port 16 are arranged in the second transition cavity 14. The outer course is a reaction cavity 12, and most of the reaction tube 11 is in the reaction cavity 12.
As shown in fig. 3, a plurality of baffles 19 are provided on the outer periphery of the condensation reaction kettle 8, i.e., in the reaction chamber 12, and the baffles 19 can change the flow direction of the reaction liquid. The reaction chamber 12 has a liquid inlet 15 at the upper part of the front end, a liquid outlet 17 at the bottom, and a second exhaust port 18 at the upper part of the rear end of the reaction chamber 12. An exhaust valve may be provided at a suitable position in the duct at the rear end of the second exhaust port 18. The gas discharged from the first and second gas discharge ports 16 and 18 may be transferred to the condenser 9 through necessary pipes for condensation. The condensed system may be further separated in the gas-liquid separation tank 10, the gas is separated from the upper portion of the gas-liquid separation tank 10, and the liquid is discharged from the lower portion, and is usually subjected to further rectification treatment or the like. As shown in fig. 1, the first exhaust port 16 and the second exhaust port 18 are controlled to be opened and closed by exhaust valves on the respective pipes.
The reaction liquid is conveyed from the mixer 7 to the liquid inlet 15 below the condensation reaction kettle 8, enters the reaction tube 11 through the first transition cavity 13, performs condensation reaction in the reaction tube 11, then passes through the second transition cavity 14, and is exhausted through the first exhaust port 16 at the moment, meanwhile, the reaction liquid is discharged from the liquid outlet 17 of the second transition cavity 14, enters the outer-range reaction cavity 12 again through the necessary pipeline from the liquid inlet 15 of the reaction cavity 12, and continues to perform condensation reaction in the reaction cavity 12, and the heat released by the reaction of the reaction tube 11 can be subjected to heat exchange with the reaction liquid in the reaction cavity 12, only the tube wall of the reaction tube 11 is separated between the reaction tube 11, the heat exchange effect is excellent, the whole production device can be realized, and a heat source is not required to be independently arranged except for preheating raw materials.
Further, as shown in FIGS. 2 to 3, the reaction chamber 12 includes a partition 20, an upper chamber 21, and a lower chamber 22, the partition 20 serving to isolate the upper chamber 21 and the lower chamber 22; the reaction liquid flows through the upper chamber 21 and the lower chamber 22 from the liquid inlet 15 of the reaction chamber 12, and flows out from the liquid outlet 17 of the reaction chamber 12; a plurality of baffles 19 for changing the flowing direction of the reaction liquid are arranged in the upper chamber 21 and the lower chamber 22 at intervals, and the baffles 19 are arranged in a staggered and opposite mode. The upper chamber 21 and the lower chamber 22 are the same in height. The height of the plurality of baffles 19 of the upper chamber 21 is 50-80% of the height of the upper chamber 21; the height of the plurality of baffles 19 of the lower chamber 22 is 50-80% of the height of the lower chamber 22.
Further, two adjacent baffles 19 in the upper chamber 21 are provided on the upper wall of the upper chamber 21 and the partition 20, respectively, and two adjacent baffles 19 in the lower chamber 22 are provided on the lower wall of the lower chamber 21 and the partition 20, respectively. The upper chamber 21 and the lower chamber 22 are provided with 4 to 1000 baffles in total. 16 baffles are shown in fig. 3, but the number of baffles representing the present invention is not so limited.
Further, the reaction tube 11 may be a U-shaped reaction tube. 1 to 1000 reaction tubes 11. For example, a U-shaped reactor tube bundle commonly used in industry may be employed. The tube diameter of the U-shaped reaction tube bundle can be 8-60 mm.
Further, the condensation reaction kettle 8 further comprises a supporting plate 23 for supporting the reaction tube 11, and the supporting plate 23 is fixedly connected to the kettle wall of the condensation reaction kettle 8.
Further, the plane in which the support plate 23 is located is a vertical plane, and the support plate 23 is provided with a through hole for passing the reaction tube 11 therethrough. This arrangement makes it possible to fix the support plate 23 in the condensation reactor 8 and thus the reaction tube 11.
The following detailed description of the present invention is provided in connection with specific embodiments so that those skilled in the art may better understand and practice the present invention, but is not intended to limit the scope of the present invention.
In the following specific examples, the conversion (C) of acetone and the reaction selectivity (S) of α -isophorone were calculated by the following formulas, respectively:
C% = 100% × (amount of acetone before reaction-amount of acetone after reaction)/amount of acetone before reaction S% = 100% × amount of condensation reaction to form α -isophorone x 3/(amount of acetone before reaction-amount of acetone after reaction)
Example 1
The embodiment provides a method for producing isophorone by an acetone liquid condensation method, which adopts the production device and comprises the following specific steps:
As shown in fig. 1-3, a horizontal condensation reaction kettle is selected, wherein the length of a cylinder body of the horizontal condensation reaction kettle is 5000mm, the diameter of the cylinder body of the horizontal condensation reaction kettle is 400mm, the pipe diameter of a pipe bundle in which a U-shaped reaction pipe is arranged is 16mm, the number of the pipe bundles is 100, and the pipe bundles are uniformly distributed in an inner range; the upper chamber and the lower chamber are respectively provided with 16 baffles, the baffles are arranged in a staggered manner, and the heights of the baffles are respectively 80% of the heights of the upper chamber and the lower chamber. Under continuous steady-state operation conditions, 80kg of KOH aqueous solution (catalyst solution) with the mass concentration of 3% and 4000kg of acetone are taken as catalyst solution and reactant, the catalyst and reactant are fed in proportion (the mass ratio of the catalyst to the reactant is 0.0006:1, the catalyst is calculated as solute) and are preheated to 150 ℃ respectively through a catalyst preheater 3 and an acetone preheater 4, the catalyst and the acetone preheater are fully mixed together through a static mixer 7 and enter a condensation reaction kettle 8, condensation reaction is carried out in the condensation reaction kettle 8 under the reaction pressure of 2.0MPa (gauge pressure), the reaction feeding speed is 30kg/min flow (the sum of the acetone and the KOH aqueous solution), the exhaust is carried out at small flow through a control exhaust valve of a first exhaust port 16 and a second exhaust port 18 in the reaction process, the reaction liquid in the condensation reaction kettle 8 is cooled after the condensation reaction is finished, sampling is detected by GC, and the acetone conversion rate is calculated to be 40.1%, and the selectivity of alpha-isophorone is 92.3%.
Examples 2 to 15
Examples 2-15 provide a process for producing isophorone by acetone liquid phase condensation, the specific steps are basically the same as in example 1, except that: based on acetone, the mass of the acetone is unchanged, the mass ratio of the catalyst to the acetone is adjusted, and the reaction conditions (catalyst type, catalyst mass concentration, catalyst/acetone mass ratio, preheating temperature, reaction pressure (gauge pressure), feeding mass flow rate, length of a reaction kettle) and the like in the acetone polycondensation reaction are adjusted, wherein the specific conditions and the reaction results are shown in the following table 1.
Table 1 reaction conditions and results for each example
Comparative example 1
Comparative example 1 provides a process for producing isophorone by an acetone liquid phase condensation method, which uses a production apparatus substantially the same as that of example 1, except that: the condensation reaction kettle 8 is not provided with a first exhaust port 16 and a second exhaust port 18. The same procedure as in example 1 was followed. The result shows that: with the progress of the reaction, the gas generated in the reaction kettle can not be discharged, the pressure in the reactor fluctuates within the range of 1.5-3.0 MPa, the fluctuation of the discharge flow of the reaction kettle is difficult to control stably, the reaction liquid in the condensation reaction kettle 8 is cooled after the polycondensation reaction is finished, the reaction liquid is subjected to GC detection, and the acetone conversion rate is 33.6% and the selectivity of alpha-isophorone is 75.2% obtained through calculation.
Comparative example 2
Comparative example 2 provides a process for producing isophorone by an acetone liquid phase condensation method, which employs a general tubular reactor for reaction under supercritical conditions. The tube length of the tube reactor was 50000mm and the diameter was 120mm. The specific operation is as follows:
2kg of 3% by mass KOH aqueous solution and 100kg of acetone (the mass ratio of 0.0006:1, the catalyst based on solute) were uniformly mixed to obtain a suspension, and the suspension was subjected to polycondensation reaction in a tubular reactor under supercritical conditions of 8MPa at 270℃and injected into the tubular reactor at a flow rate of 30 kg/min. After the polycondensation reaction was completed, the reaction liquid in the tubular reactor was cooled, sampled and detected by GC, and the acetone conversion was calculated to be 38.2%, and the selectivity of α -isophorone was 88.7%.
Comparative example 3
Comparative example 3 provides a method for producing isophorone by an acetone liquid phase condensation method, which uses a common U-tube heat exchanger for reaction. Other reaction conditions were the same as in example 1. The method is characterized in that as the reaction proceeds, non-condensable gas generated by the reaction in the U-shaped tube heat exchanger cannot be discharged, the acetone feed pump and the catalyst solution feed pump are severely vibrated, the pressure in the reactor is difficult to control stably, the coupling heat exchange effect is poor due to gas accumulation, the reaction outlet temperature is difficult to maintain as the reaction proceeds for 20min, the reaction outlet temperature is in a descending trend, and the reaction is stopped at the moment due to safety. GC detection was performed on the reaction solution in the same manner, and the acetone conversion was calculated to be 28.5% and the selectivity to alpha-isophorone was 67.3%.
The above embodiments are provided to illustrate the technical concept and features of the present invention and are intended to enable those skilled in the art to understand the content of the present invention and implement the same, and are not intended to limit the scope of the present invention. All equivalent changes or modifications made in accordance with the spirit of the present invention should be construed to be included in the scope of the present invention.

Claims (14)

1. A process for producing isophorone by condensing acetone in the liquid phase in the presence of a catalyst solution to produce isophorone, characterized in that: the condensation reaction is carried out in a condensation reaction kettle, and the condensation reaction kettle comprises a reaction tube, a reaction cavity, a first transition cavity and a second transition cavity;
The inlet of the reaction tube is communicated with the first transition cavity, and the outlet of the reaction tube is communicated with the second transition cavity;
At least part of the reaction tube is positioned in the reaction cavity, and the reaction liquid in the reaction tube exchanges heat with the reaction liquid in the reaction cavity;
The first transition chamber is provided with a liquid inlet, the second transition chamber is provided with a first exhaust port and a liquid outlet, and the reaction chamber is provided with a liquid inlet, a liquid outlet and a second exhaust port;
The liquid outlet of the second transition cavity is connected with the liquid inlet of the reaction cavity, so that the reaction liquid enters the first transition cavity from the liquid inlet of the first transition cavity, flows through the reaction tube to sequentially enter the second transition cavity, and then enters the reaction cavity through the liquid outlet of the second transition cavity and the liquid inlet of the reaction cavity;
the method comprises the steps of enabling the reaction liquid to sequentially flow through the reaction tube, the second transition cavity and the reaction cavity to carry out condensation reaction, and enabling the reaction liquid to be exhausted through the first exhaust port and the second exhaust port.
2. The process for producing isophorone according to claim 1, wherein: a plurality of baffles used for changing the flowing direction of the reaction liquid are arranged in the reaction cavity at intervals, and the baffles are arranged in a staggered and opposite mode.
3. The process for producing isophorone according to claim 1, wherein: the reaction cavity comprises a baffle plate, an upper cavity and a lower cavity, wherein the baffle plate is used for isolating the upper cavity from the lower cavity; the reaction liquid flows through the upper chamber and the lower chamber from the liquid inlet of the reaction chamber and flows out from the liquid outlet of the reaction chamber; a plurality of baffles for changing the flowing direction of the reaction liquid are arranged in the upper chamber and the lower chamber at intervals, and the baffles are arranged in a staggered and opposite way; preferably, 4-1000 baffles are arranged in the upper chamber and the lower chamber.
4. A process for producing isophorone according to claim 3, wherein: two adjacent baffles in the upper chamber are respectively arranged on the upper wall and the partition plate of the upper chamber, and two adjacent baffles in the lower chamber are respectively arranged on the lower wall and the partition plate of the lower chamber.
5. A process for producing isophorone according to claim 3, wherein: the heights of the upper chamber and the lower chamber are the same, and the heights of the plurality of baffles of the upper chamber and the lower chamber are the same; and/or the heights of the baffles of the upper chamber are 20% -80% of the height of the upper chamber; the height of the baffles of the lower chamber is 20% -80% of the height of the lower chamber.
6. The process for producing isophorone according to claim 1, wherein: the second transition cavity is positioned above the first transition cavity; the first exhaust port is positioned at the upper part of the second transition cavity; the second exhaust port is positioned at the upper part of the reaction cavity.
7. The process for producing isophorone according to claim 6, wherein: the condensation reaction kettle is a horizontal reaction kettle, the liquid inlet of the reaction cavity is positioned at the front end of the reaction cavity, the second exhaust port is positioned at the upper part of the rear end of the reaction cavity, and preferably, the length of a cylinder body of the horizontal reaction kettle is 3000-50000 mm, and the diameter of the cylinder body of the horizontal reaction kettle is 300-5000 mm; and/or the reaction tube is a U-shaped reaction tube.
8. The process for producing isophorone according to claim 1, wherein: the condensation reaction kettle further comprises a supporting plate for supporting the reaction tube, and the supporting plate is fixedly connected to the kettle wall of the condensation reaction kettle; preferably, the plane of the supporting plate is a vertical plane, and the supporting plate is provided with a through hole for the reaction tube to pass through; and/or 1-1000 reaction tubes; and/or the pipe diameter of the reaction pipe is 8-60 mm.
9. The process for producing isophorone according to claim 1, wherein: the method further comprises the step of mixing the acetone and the catalyst solution in a mixer to obtain the reaction liquid; preferably, the mixer is a static mixer; and/or, the method further comprises the step of preheating the acetone and catalyst solution; and/or the method further comprises the steps of condensing the gas discharged from the first exhaust port and the second exhaust port and then performing gas-liquid separation; and/or the method further comprises the step of rectifying the reaction liquid after the condensation reaction.
10. The process for producing isophorone according to claim 1, wherein: the temperature of the reaction liquid when entering the reactor is 120-220 ℃; and/or the condensation reaction is carried out at a pressure of 0.5 to 10 MPa; and/or the feeding mass flow rate of the reaction liquid is 5-3000 kg/min; and/or the mass ratio of the catalyst in the catalyst solution to the acetone is 0.0001-0.01:1; and/or the mass concentration of the catalyst solution is 1-30%.
11. A production apparatus for the process for producing isophorone according to any one of claims 1 to 10, wherein: the production device comprises a mixer and a condensation reaction kettle which are connected in sequence;
the mixer is used for mixing acetone and a catalyst solution to obtain a reaction solution;
the condensation reaction kettle comprises a reaction tube, a reaction cavity, a first transition cavity and a second transition cavity;
The inlet of the reaction tube is communicated with the first transition cavity, and the outlet of the reaction tube is communicated with the second transition cavity;
At least part of the reaction tube is positioned in the reaction cavity, and the reaction liquid in the reaction tube exchanges heat with the reaction liquid in the reaction cavity;
The first transition chamber is provided with a liquid inlet, the second transition chamber is provided with a first exhaust port and a liquid outlet, and the reaction chamber is provided with a liquid inlet, a liquid outlet and a second exhaust port;
The liquid outlet of the second transition cavity is connected with the liquid inlet of the reaction cavity, so that the reaction liquid enters the first transition cavity from the liquid inlet of the first transition cavity, flows through the reaction tube to sequentially enter the second transition cavity, and then enters the reaction cavity through the liquid outlet of the second transition cavity and the liquid inlet of the reaction cavity;
the first exhaust port and the second exhaust port are used for exhausting the reaction liquid.
12. The production device according to claim 11, wherein: the reaction cavity comprises a baffle plate, an upper cavity and a lower cavity, wherein the baffle plate is used for isolating the upper cavity from the lower cavity; the reaction liquid flows through the upper chamber and the lower chamber from the liquid inlet of the reaction chamber and flows out from the liquid outlet of the reaction chamber; a plurality of baffles for changing the flowing direction of the reaction liquid are arranged in the upper chamber and the lower chamber at intervals, and the baffles are arranged in a staggered and opposite way; preferably, 4-1000 baffles are arranged in the upper chamber and the lower chamber; and/or the second transition chamber is located above the first transition chamber; the first exhaust port is positioned at the upper part of the second transition cavity; the second exhaust port is positioned at the upper part of the reaction cavity.
13. The production device according to claim 12, wherein: two adjacent baffles in the upper chamber are respectively arranged on the upper wall and the partition plate of the upper chamber, and two adjacent baffles in the lower chamber are respectively arranged on the lower wall and the partition plate of the lower chamber.
14. The production device according to claim 12, wherein: the condensation reaction kettle is a horizontal reaction kettle, a liquid inlet of the reaction cavity is positioned at one end of the reaction cavity, and the second exhaust port is positioned at the upper part of the other end of the reaction cavity; preferably, the length of the cylinder body of the horizontal reaction kettle is 3000-50000 mm, and the diameter is 300-5000 mm; and/or the reaction tube is a U-shaped reaction tube, preferably, the tube diameter of the reaction tube is 8-60 mm, and the number of the reaction tubes is 1-1000.
CN202411016739.1A 2024-07-26 Method and device for producing isophorone by folding reactor Pending CN118949905A (en)

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CN118949905A true CN118949905A (en) 2024-11-15

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