Preparation and recovery system applied to allyl acetate
By having multiple devices in the recycling system work together, the problem of recycling propylene and propane during the preparation of allyl acetate was solved, achieving a win-win situation for both economic and environmental benefits, improving the selectivity of the target product and reducing production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-06
- Publication Date
- 2026-03-27
AI Technical Summary
In the existing technology, unreacted inert gases such as propylene and propane cannot be effectively recovered and utilized during the preparation of allyl acetate, resulting in economic losses and environmental pollution. Furthermore, the accumulation of circulating gases affects the pressure balance and safety of the reaction system.
By employing the coordinated operation of a reactor, a first absorption tower, a first condenser, a first compressor, a second absorption tower, a crude product storage tank, a second compressor, a distillation tower, a gas-liquid separator, and a second condenser, propylene and propane are recovered and reused through distillation and the use of absorbent liquid, thereby reducing the propylene and propane content in the exhaust gas.
This approach enables the efficient recycling of propylene and propane, suppresses side reactions and reduces the heat of reaction, improves the selectivity of the target product allyl acetate, reduces production costs and carbon dioxide emissions.
Smart Images
Figure CN224040892U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of gas recycling, and particularly relates to a preparation and recovery system for allyl acetate. BACKGROUND
[0002] Allyl acetate is an important fine chemical product and has a wide range of uses. Allyl acetate is mainly obtained from propylene, acetic acid and oxygen as raw materials under the catalytic oxidation of metal pd.
[0003] The single-pass conversion rate of propylene in the acetyl oxidation reaction is less than 20%, so that the reaction material after the reaction includes a mixture of allyl acetate, propylene, oxygen, acetic acid, water, carbon dioxide and other inert gases. After the reaction mixture is separated by condensation and an absorption tower to remove heavy components, the light components contain unreacted propylene, oxygen, acetic acid, carbon dioxide and other inert gases. After the light components are pressurized by a compressor, most of them are returned to the reactor to continue to participate in the reaction.
[0004] Considering the process cost, both the raw material propylene and the oxygen are industrial raw materials, and there is no impurity gas separation process before the raw material gas enters the reactor. Generally, the purity of industrial polymerization-grade propylene is greater than >99.6%, and the main impurity is propane. The purity of industrial oxygen is greater than >99.5%, and the main impurity components are nitrogen and argon. The three kinds of inert gases in the circulating gas do not participate in the reaction, and if the above three gases are not discharged from the reaction system, they will continuously accumulate, seriously affecting the pressure balance and chemical equilibrium of the reaction system, and even cause explosion. Therefore, during the reaction, a part of the circulating gas is continuously discharged to a flare to remove the inert substances from the reaction system. Because the circulating gas contains a large amount of propylene, direct sending to the flare not only causes economic loss, but also produces a large amount of greenhouse gas, pollutes the environment and increases the environmental protection burden of the enterprise. SUMMARY
[0005] In order to overcome the shortcomings of the prior art, the purpose of the utility model is to provide a preparation and recovery system for allyl acetate. The preparation and recovery system provided by the present application is beneficial to simplify the process of recycling propylene and propane, and the recycled propylene and propane can be transported back to the reactor as a circulating gas stream to participate in the reaction, which on the one hand realizes the recycling of the reaction material propylene, and on the other hand is beneficial to inhibit the side reaction and reduce the reaction heat effect to increase the selectivity of the target product allyl acetate. Moreover, the system provided by the present application can also reduce the content ratio of propylene and propane in the exhaust gas, so that the preparation and recovery system provided by the present application is beneficial to reduce the production cost, improve the selectivity of the target product and reduce the carbon dioxide emission of the system.
[0006] To solve the above problems, the technical scheme adopted by the utility model is as follows:
[0007] A system for the preparation and recovery of allyl acetate comprising a reactor, a first absorption column and a first condenser, said reactor having a first duct for the introduction of gaseous material at its top, said first absorption column being connected to the bottom of said reactor by means of a second duct, said first condenser being installed in said second duct for condensing the material exiting from said reactor, said first absorption column having a third duct connected to said first duct at its top, said system for the preparation and recovery further comprising:
[0008] a first compressor installed in said third duct for pumping the gases exiting from said first absorption column;
[0009] a second absorption column, said second absorption column having a fourth duct connected to the portion of said third duct adjacent to said first duct, said fourth duct having a fifth duct for the removal of part of the material from the system;
[0010] a crude product tank, said crude product tank being connected to the bottom of said first absorption column by means of a sixth duct and to the lower middle portion of said first absorption column by means of a seventh duct, said second absorption column having an eighth duct connected to said crude product tank;
[0011] a second compressor installed in said seventh duct for pumping the flash gases from said crude product tank into said first absorption column;
[0012] a rectification column for the rectification separation of the material exiting from said crude product tank, said rectification column having a ninth duct connected to said crude product tank at its middle portion, said rectification column having a tenth duct for the removal of liquid at its bottom;
[0013] a gas-liquid separation tank connected to said rectification column by means of at least two eleventh ducts for the separation of the rectified material and for the reflux of said rectification column, said gas-liquid separation tank having a twelfth duct connected to the top of said second absorption column at its bottom; and
[0014] a second condenser installed in said twelfth duct for condensing the material exiting from said gas-liquid separation tank, said second absorption column having a thirteenth duct connected to said fifth duct at its top.
[0015] In some possible embodiments, said gas-liquid separation tank is connected to said crude product tank by means of a fourteenth duct for the introduction of the separated gases into said crude product tank.
[0016] In some possible embodiments, said first absorption column also has a fifteenth duct for the introduction of absorption liquid at its top, said absorption liquid being used for the absorption of the non-condensed material vapors.
[0017] In some possible implementation manners, the first compressor is a centrifugal compressor or an axial compressor.
[0018] In some possible implementation manners, the second compressor is one of a liquid ring compressor, a reciprocating compressor or a screw compressor.
[0019] In some possible implementation manners, the reactor is a shell-and-tube reactor.
[0020] In some possible implementation manners, the system further comprises:
[0021] A delivery pump is installed on the twelfth pipeline for delivering the material discharged from the gas-liquid separation tank, and the delivery pump is arranged between the second condenser and the gas-liquid separation tank.
[0022] In some possible implementation manners, the second absorption tower is one of a packed tower, a plate tower or a float valve tower.
[0023] In some possible implementation manners, the second absorption tower is arranged between the first absorption tower and the gas-liquid separation tank.
[0024] Compared with the prior art, the preparation and recovery system has the beneficial effects that:
[0025] In the present application, through the cooperation between the reactor, the first absorption tower, the first condenser, the first compressor, the second absorption tower, the crude product storage tank, the second compressor, the rectification tower, the gas-liquid separation tank and the second condenser, the oil phase component separated by the rectification tower is used as an absorption liquid for separating propylene, propane and other impurity gases, without introducing other organic components, which is beneficial to simplify the process of recovering propylene and propane, and the recovered propylene and propane can be transported into the reactor to participate in the reaction, on the one hand, the recovery and utilization of the reactant propylene are realized, and on the other hand, the selectivity of the target product allyl acetate is increased by inhibiting the side reaction and reducing the reaction heat effect. Therefore, the preparation and recovery system is beneficial to reduce the production cost and increase the selectivity of the target product.
[0026] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS
[0027] Figure 1 The preparation and recovery system provided by an embodiment of the present application is connected with an RTO.
[0028] DESCRIPTION OF THE DRAWINGS
[0029] 10 - reactor; 20 - first absorption column; 30 - first condenser; 40 - second absorption column; 50 - crude product tank; 60 - rectification column; 70 - gas-liquid separation tank; 80 - second condenser; 90 - delivery pump; 11 - first pipe; 12 - second pipe; 21 - third pipe; 22 - first compressor; 23 - fourth pipe; 24 - fifth pipe; 25 - sixth pipe; 26 - fifteenth pipe; 41 - eighth pipe; 42 - thirteenth pipe; 51 - seventh pipe; 52 - second compressor; 53 - ninth pipe; 61 - tenth pipe; 62 - eleventh pipe; 71 - twelfth pipe; 72 - fourteenth pipe. DETAILED DESCRIPTION
[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.
[0031] The terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish different objects, rather than to describe a particular order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. It should be noted that when an element is referred to as "fixed to" another element, it can be directly on the other element or there can be a middle element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or there can be a middle element. When an element is referred to as "provided on" another element, it can be provided on the other element or there can be a middle element.
[0032] Reference Figure 1 An embodiment of the present application provides a preparation and recovery system for allyl acetate, hereinafter referred to as the preparation and recovery system. The preparation and recovery system comprises a reactor 10, a first absorption column 20, a first condenser 30, a first compressor 22, a second absorption column 40, a crude product tank 50, a second compressor 52, a rectification column 60, a gas-liquid separation tank 70, and a second condenser 80.
[0033] The top of the reactor 10 is connected to a first pipe 11 for introducing gas materials. Propylene, acetic acid, oxygen and inert gas can be introduced into the reactor 10 through the first pipe 11 for reaction, and a corresponding catalyst, such as a supported pd catalyst, can be provided in the reactor 10. The bottom of the first absorption tower 20 is connected to the bottom of the reactor 10 through a second pipe 12. A first condenser 30 is installed on the second pipe 12 for condensing materials discharged from the reactor 10, so that the product discharged from the bottom of the reactor 10 is introduced into the first absorption tower 20 in a liquid form, and the residual gas materials can be introduced into the first absorption tower 20 in a gas form. The gas materials introduced into the first absorption tower 20 include propylene, oxygen, uncondensed acetic acid propyl ester vapor and inert gas (including inert gas such as propane, nitrogen and argon).
[0034] The top of the first absorption tower 20 is connected to the first pipe 11 through a third pipe 21, so that the gas materials in the first absorption tower 20 can be circulated into the reactor 10. A first compressor 22 is installed on the third pipe 21 for pumping the gas discharged from the first absorption tower 20. The bottom of the second absorption tower 40 is connected to the portion of the third pipe 21 adjacent to the first pipe 11, i.e. the access point of the fourth pipe 23 to the third pipe 21 is located on the side of the first compressor 22 away from the first absorption tower 20, so that the first compressor 22 can serve as the driving source of the third pipe 21 and the fourth pipe 23, and it can be understood that a regulating valve can be provided on each of the third pipe 21 and the fourth pipe 23 to regulate the flow of the corresponding pipe. The fourth pipe 23 is provided so that a portion of the circulating gas stream in the third pipe 21 is discharged as a vent gas stream, and a portion of the vent gas stream enters the second absorption tower 40 through the fourth pipe 23. The fourth pipe 23 is connected to a fifth pipe 24 for discharging a portion of the materials from the system, i.e. another portion of the vent gas stream in the fourth pipe 23 is discharged from the system through the fifth pipe 24, and the vent gas stream discharged through the fifth pipe 24 can be introduced into a regenerative thermal oxidizer (RTO) for incineration treatment, for example. A regulating valve can be provided on each of the fourth pipe 23 and the fifth pipe 24, so as to regulate the flow into the second absorption tower 40 and the flow discharged from the system.
[0035] The crude product storage tank 50 is connected to the bottom of the first absorption tower 20 through the sixth pipeline 25 and to the middle-lower part of the first absorption tower 20 through the seventh pipeline 51, so that the access point of the seventh pipeline 51 to the first absorption tower 20 is higher than that of the sixth pipeline 25 to the first absorption tower 20, and the material discharged from the bottom of the first absorption tower 20 can flow into the crude product storage tank 50 through the sixth pipeline 25. The gas flashed in the crude product storage tank 50 can be introduced into the first absorption tower 20 through the seventh pipeline 51, and then pumped out of the first absorption tower 20 by the first compressor 22. For example, the access point of the seventh pipeline 51 can be above the liquid phase space and below the tower packing. For example, both the sixth pipeline 25 and the seventh pipeline 51 can access the top of the crude product storage tank 50. The bottom of the second absorption tower 40 is connected to the crude product storage tank 50 through the eighth pipeline 41, so that the rich liquid obtained after the treatment of the exhaust gas stream in the second absorption tower 40 is introduced into the crude product storage tank 50. The second compressor 52 is installed on the seventh pipeline 51 for pumping the flashed gas in the crude product storage tank 50 into the first absorption tower 20.
[0036] The rectification tower 60 is used for rectification separation of the material discharged from the crude product storage tank 50. The middle part of the rectification tower 60 is connected to the crude product storage tank 50 through the ninth pipeline 53, and the bottom of the rectification tower 60 is provided with the tenth pipeline 61 for discharging liquid. The gas-liquid separation tank 70 is connected to the rectification tower 60 through at least two eleventh pipelines 62 for separating the rectified material and realizing reflux of the rectification tower 60. The bottom of the gas-liquid separation tank 70 is connected to the top of the second absorption tower 40 through the twelfth pipeline 71. The second condenser 80 is installed on the twelfth pipeline 71 for condensing the material discharged from the gas-liquid separation tank 70, so that part of the material discharged from the gas-liquid separation tank 70 is condensed as the overhead feed of the second absorption tower 40 to absorb propylene and propane. The absorbed propylene and propane are introduced into the crude product storage tank 50 through the eighth pipeline 41, then flashed, and the flashed propylene and propane are re-pumped into the circulating gas stream, so as to increase the content ratio of propylene and propane in the circulating gas stream, thereby inhibiting the generation of the 10 side reactions in the reactor and reducing the heat effect of the reaction, so as to increase the selectivity of the target product allyl acetate. The top of the second absorption tower 40 is connected to the fifth pipeline 24 through the thirteenth pipeline 42, so that the waste gas removed of propylene and propane and another stream separated from the exhaust gas stream are combined into one gas stream and discharged to the outside of the system. For example, they can be discharged into the RTO for incineration.
[0037] In the present application, through the cooperation between the reactor 10, the first absorption tower 20, the first condenser 30, the first compressor 22, the second absorption tower 40, the crude product storage tank 50, the second compressor 52, the rectification tower 60, the gas-liquid separation tank 70 and the second condenser 80, the oil phase component separated by the rectification tower 60 is used as an absorption liquid for separating propylene, propane and other impurity gases, without introducing other organic components, which is conducive to simplifying the process of recovering propylene and propane, and the recovered propylene and propane can be transported back to the reactor 10 to participate in the reaction, which on the one hand realizes the recycling of the reactant propylene, and on the other hand is conducive to inhibiting side reactions and reducing the heat effect of the reaction to increase the selectivity of the target product allyl acetate. Moreover, the system provided by the present application can also reduce the content ratio of propylene and propane in the exhaust gas. Therefore, the preparation and recovery system provided by the present application is conducive to reducing production costs, improving the selectivity of the target product and reducing the amount of carbon dioxide emissions.
[0038] In some embodiments, the gas-liquid separation tank 70 is communicated with the crude product storage tank 50 through a fourteenth pipeline 72 for guiding the separated gas into the crude product storage tank 50, thereby further improving the recovery ratio of propylene and propane. For example, the fourteenth pipeline 72 can be communicated with the top of the gas-liquid separation tank 70 and the top of the crude product storage tank 50.
[0039] In some embodiments, the top of the first absorption tower 20 is also communicated with a fifteenth pipeline 26 for feeding an absorption liquid, which is used to absorb the uncondensed material vapor. For example, the absorption liquid can be an aqueous acetic acid solution.
[0040] In some embodiments, the first compressor 22 is a centrifugal compressor or an axial flow compressor.
[0041] In some embodiments, the second compressor 52 is one of a liquid ring compressor, a reciprocating compressor or a screw compressor. The types of the first compressor 22 and the second compressor 52 are selected to have the advantages of low equipment cost and high pumping efficiency, thereby also being conducive to further reducing production costs.
[0042] In some embodiments, the reactor 10 is a shell-and-tube reactor, which has the advantages of good heat transfer performance and good mixing performance.
[0043] In some embodiments, the preparation and recovery system further comprises a delivery pump 90 installed on the twelfth pipeline 71 for delivering the material discharged from the gas-liquid separation tank 70. The delivery pump 90 is arranged between the second condenser 80 and the gas-liquid separation tank 70, and the delivery of the material by the delivery pump 90 is conducive to improving the delivery efficiency.
[0044] In some embodiments, the second absorption tower 40 is one of a packed tower, a plate tower or a float valve tower.
[0045] In some embodiments, the second absorption tower 40 is arranged between the first absorption tower 20 and the gas-liquid separation tank 70, so as to facilitate ensuring that the absorption liquid in the second absorption tower 40 can timely absorb the propylene and the propane, and also facilitating reducing the conveying power consumption of the materials.
[0046] In some embodiments, the first absorption tower 20 can be one of a packed tower, a plate tower or a float valve tower.
[0047] The above-mentioned embodiments are only preferred embodiments of the present application, and cannot be used to limit the scope of protection of the present application. Any non-essential changes and replacements made by those skilled in the art on the basis of the present application shall fall within the scope of protection of the present application.
Claims
1. A system for recovering allyl acetate, comprising a reactor, a first absorption tower, and a first condenser, a first pipe for introducing a gaseous material into the top of the reactor, a second pipe for connecting the bottom of the reactor to the bottom of the first absorption tower, and the first condenser installed in the second pipe for condensing the material discharged from the reactor, characterized in that, The top of the first absorption tower is communicated with the first pipeline through a third pipeline, and the preparation recovery system further comprises: a first compressor installed on the third pipeline for pumping the gas discharged from the first absorption tower; a second absorption tower, the bottom of which is communicated with the part of the third pipeline adjacent to the first pipeline through a fourth pipeline, and the fourth pipeline is communicated with a fifth pipeline for discharging part of the material from the system; a crude product storage tank communicated with the bottom of the first absorption tower through a sixth pipeline and with the middle and lower part of the first absorption tower through a seventh pipeline, and the bottom of the second absorption tower is communicated with the crude product storage tank through an eighth pipeline; a second compressor installed on the seventh pipeline for pumping the flash gas in the crude product storage tank into the first absorption tower; a rectifying tower for rectifying and separating the material discharged from the crude product storage tank, the middle part of which is communicated with the crude product storage tank through a ninth pipeline, and the bottom of which is provided with a tenth pipeline for discharging liquid; a gas-liquid separation tank communicated with the rectifying tower through at least two eleventh pipelines for separating the material after rectification and realizing reflux of the rectifying tower, and the bottom of which is communicated with the top of the second absorption tower through a twelfth pipeline; and a second condenser installed on the twelfth pipeline for condensing the material discharged from the gas-liquid separation tank, and the top of the second absorption tower is communicated with the fifth pipeline through a thirteenth pipeline.
2. The manufacturing recovery system of claim 1, wherein, The gas-liquid separation tank is communicated with the crude product storage tank through a fourteenth pipeline for guiding the separated gas into the crude product storage tank.
3. The manufacturing recovery system of claim 1, wherein, The top of the first absorption tower is further communicated with a fifteenth pipeline for feeding absorption liquid, which is used for absorbing the uncondensed material vapor.
4. The manufacturing recovery system of claim 1, wherein, The first compressor is a centrifugal compressor or an axial flow compressor.
5. The manufacturing recovery system of claim 1, wherein, The second compressor is one of a liquid ring compressor, a reciprocating compressor or a screw compressor.
6. The manufacturing recovery system of claim 1, wherein, The reactor is a tubular reactor.
7. The manufacturing recovery system of claim 1, wherein, Further comprising: a delivery pump installed on the twelfth pipeline for delivering the material discharged from the gas-liquid separation tank, which is arranged between the second condenser and the gas-liquid separation tank.
8. The manufacturing recovery system of claim 1, wherein, The second absorption tower is one of a packed tower, a plate tower or a float valve tower.
9. The manufacturing recovery system of claim 1, wherein, The second absorption tower is arranged between the first absorption tower and the gas-liquid separation tank.