Backpack tower internal reaction rectification device and method of using same

Abstract

The application discloses a backpack type reaction rectification device in a tower and a use method thereof, and relates to the field of chemical production equipment. The device comprises a reaction rectification tower, a separation heating component, a liquid buffer component, a reboiler, an evaporator, a cooling fractionating tower, a steam permeation membrane unit and a condenser. The separation heating component is horizontally arranged in the middle part of the reaction rectification tower, and the heating side is located at the upper part. The upper reaction section is connected with the liquid buffer component, the lower reaction section and the evaporator in sequence through pipelines. The lower reaction section is connected with the steam permeation membrane unit, the cooling fractionating tower, the evaporator and the upper reaction section in sequence through pipelines. The rectification section is connected with the condenser through a pipeline. The reboiler is connected with the rectification section through a pipeline. The cooling fractionating tower and the membrane equipment are coupled in the reaction rectification process. The product is continuously removed to break the original chemical equilibrium, promote the forward movement of the equilibrium and improve the conversion degree of the reaction.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical production equipment, in particular to a backpack type in-tower reaction rectification device and a use method thereof. BACKGROUND

[0002] Reaction rectification is a special field in distillation technology, which combines chemical reaction process and rectification through a reaction rectification tower, has the advantages of good selectivity, high yield, low energy consumption and less equipment investment, and so far, reaction rectification operation has been widely used in petroleum chemical production, and some substances such as MEBE and ETBE are synthesized by using reaction rectification method, which has been completely industrialized. This technology is suitable for various types of reactions, such as consecutive reactions, reversible reactions, etc., but is mainly applied to reaction systems whose conversion rate is limited by chemical equilibrium.

[0003] Vapor permeation process is a new type of membrane separation technology, which realizes separation by using the difference in solubility and diffusion rate of vapor mixture or vapor and non-condensable gas mixture in dense membrane. Due to the limitations of process capacity and membrane life of membrane separation technology, there are certain limitations in using vapor permeation technology alone to separate mixtures, so it is considered to integrate with other separation technologies to fully exert the technical advantages of each other and complement each other's advantages, so as to improve the overall economy of the process. The integrated process of reaction rectification and membrane separation is one of the important applications.

[0004] However, many important chemical systems have problems such as azeotropy, concentration pinch point, relative volatility, etc., and it is difficult to achieve high conversion rate in ordinary reaction rectification process, and the product cannot be effectively separated. Although the out-of-tower coupling of reaction rectification and membrane solves this problem to some extent, the out-of-tower coupling of membrane does not fundamentally solve the separation problem existing in the reaction rectification tower, and the factors limiting the reaction still exist in the reaction rectification process.

[0005] Therefore, how to provide a backpack type in-tower reaction rectification device, which couples a cooling fractionation tower and a membrane device together in the process of reaction rectification, continuously removes the product while reacting to break the original chemical equilibrium, promotes the positive movement of the equilibrium, and improves the conversion degree of the reaction, has become a technical problem to be solved by the person skilled in the art. SUMMARY

[0006] The purpose of the present application is to provide a backpack type in-tower reaction rectification device, which couples a cooling fractionation tower and a membrane device together in the process of reaction rectification, continuously removes the product while reacting to break the original chemical equilibrium, promotes the positive movement of the equilibrium, and improves the conversion degree of the reaction.

[0007] To solve the above technical problems, the present application adopts the following technical scheme:

[0008] The present application is a backpack type reaction rectification device in tower, including reaction rectification tower, separation heating component, liquid buffer component, reboiler, evaporator, cooling fractionating tower, steam permeation membrane unit and condenser, the reaction rectification tower is provided with rectification section, upper reaction section, lower reaction section and stripping section from top to bottom respectively, the separation heating component horizontally arranged in the middle of the reaction rectification tower separates the upper reaction section and lower reaction section into two independent chambers, and the heating side of the separation heating component is located at the bottom end of the upper reaction section;

[0009] The upper reaction section is connected with the liquid buffer component, lower reaction section in turn through pipeline, and the liquid accumulated at the bottom of the upper reaction section flows back to the stripping section through the liquid buffer component and lower reaction section in turn.

[0010] The lower reaction section is connected with the steam permeation membrane unit, cooling fractionating tower, evaporator, upper reaction section in turn through pipeline, and the steam accumulated at the top of the lower reaction section enters the stripping section through the steam permeation membrane unit, cooling fractionating tower, evaporator and upper reaction section in turn, and the steam is separated into target product and water when passing through the steam permeation membrane unit and cooling fractionating tower respectively, which destroys the balance of chemical reaction and promotes the forward reaction.

[0011] The rectification section is connected with the condenser through pipeline, and the steam after rectification enters the condenser through pipeline to generate liquid, and part of the liquid flows back to the rectification section through pipeline, and the other part of the liquid is discharged and collected.

[0012] The reboiler is connected with the stripping section through pipeline, and completes the heating operation of the liquid in the stripping section.

[0013] Preferably, the liquid buffer component includes a buffer tank and a pump, the inlet end of the buffer tank is connected with the liquid outlet of the upper reaction section through pipeline, and the outlet end of the buffer tank is connected with the liquid inlet of the lower reaction section through pipeline and pump, which completes the storage and transportation of the liquid accumulated at the bottom of the upper reaction section back to the lower reaction section.

[0014] Preferably, the cooling fractionating tower, steam permeation membrane unit and evaporator are located outside the reaction rectification tower to form a backpack type structure, the steam inlet, retention side outlet and permeation side outlet are arranged on the steam permeation membrane unit, the steam inlet is connected with the steam outlet at the top of the lower reaction section through pipeline, the retention side outlet is connected with the inlet of the cooling fractionating tower through pipeline, the steam entering the steam permeation membrane unit is removed under the driving force of the pressure difference between the inside and outside of the membrane, the removed target component is output from the permeation side outlet for collection, and other components are output from the retention side outlet into the cooling fractionating tower.

[0015] Preferably, the cooling fractionating column is provided with a plurality of fractionating collection pipes for collecting liquid products condensed at different boiling points, and each of the fractionating collection pipes is provided with a temperature measuring module and a valve, and the fractionating collection pipe generating the corresponding secondary reaction product is connected to the evaporator through a pipeline.

[0016] Preferably, the outlet end of the evaporator is connected to the upper reaction section through a pipeline, and the liquid vaporized by the evaporator enters the upper reaction section through a pipeline.

[0017] Preferably, the separation heating assembly comprises a separation plate and a heating plate, and the separation plate is internally provided with an open-ended cavity, and the heating plate is embeddedly installed in the inner cavity of the separation plate.

[0018] Preferably, the reaction rectifying column is provided with at least one feed inlet.

[0019] Preferably, a method for using a backpack type in-tower reaction rectifying device comprises the following steps:

[0020] Step one: the raw material enters the reaction rectifying column through the feed inlet, and the raw material in the stripping section becomes a gas phase component after the stripping operation and rises into the lower reaction section to undergo a reversible chemical reaction;

[0021] Step two: the gas phase component after the reaction enters the vapor permeation membrane unit, and the target component is removed under the driving force of the pressure difference between the inside and outside of the membrane, thereby breaking the balance of the reversible chemical reaction and promoting the forward chemical reaction; at the same time, the removed target component is output from the permeation side outlet for collection, and other components are output from the retention side outlet into the cooling fractionating column;

[0022] Step three: the gas phase component entering the cooling fractionating column is cooled and condensed at different temperatures, and the mixed gaseous components are gradually separated into liquid phase products of different components, the fractionating collection pipe generating the corresponding secondary reaction product is connected to the inlet of the evaporator through a pipeline, and the generated condensed water is discharged from the corresponding fractionating collection pipe for collection, thereby further removing the chemical reaction products and promoting the forward chemical reaction;

[0023] Step four: the liquid phase product entering the evaporator becomes a gas phase component again at high temperature, and enters the upper reaction section together with the gaseous component not liquefied in the cooling fractionating column to continue the chemical reaction, wherein the heating plate in the separation heating assembly provides heat for the second chemical reaction, and the gaseous component after the reaction rises to the rectifying section to start rectifying separation, and is cooled into a liquid phase product by the condenser, part of the liquid phase product is refluxed into the upper reaction section, and the other part is collected as a tower top product.

[0024] Step five, the liquid flowing back to the upper reaction section flows through the buffer tank and the pump to the stripping section, and part of the liquid in the stripping section becomes the bottom product, and the other part is vaporized by the reboiler to flow back.

[0025] Compared with the prior art, the present application has the beneficial technical effects of:

[0026] 1) The present application realizes the removal operation of target components and chemical products by coupling the steam permeation membrane unit with the cooling fractionation tower outside the reaction distillation tower, thereby breaking the equilibrium state of the reversible chemical reaction, promoting the forward progress of the chemical reaction, and improving the yield of the target product.

[0027] 2) The setting of the cooling fractionation tower realizes the classification collection and removal of chemical reaction products with different boiling points, thereby improving the content of the reaction components while reducing the content of the reaction products.

[0028] 3) The setting of the separation heating assembly provides the required heat for the chemical reaction of the upper reaction section, effectively promoting the forward progress of the chemical reaction.

[0029] Overall, the present application couples the cooling fractionation tower and the membrane equipment together in the reaction distillation process, continuously removes the products during the reaction to break the original chemical equilibrium, promotes the positive movement of the equilibrium, and improves the conversion degree of the reaction. BRIEF DESCRIPTION OF DRAWINGS

[0030] The present application will be further described below in conjunction with the drawings.

[0031] Figure 1 It is a schematic diagram of a backpack type in-tower reaction distillation device.

[0032] Marked as follows: 1, reaction distillation tower; 11, distillation section; 12, upper reaction section; 13, lower reaction section; 14, stripping section; 15, feed inlet; 2, separation heating assembly; 3, liquid buffer assembly; 31, buffer tank; 32, pump; 4, reboiler; 5, evaporator; 6, cooling fractionation tower; 61, fractionation collection pipe; 62, temperature measurement module; 63, valve; 7, steam permeation membrane unit; 71, vapor inlet; 72, retention side outlet; 73, permeation side outlet; 8, condenser. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical solutions and beneficial effects of the present application clearer, the present application will be further described in detail below in conjunction with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0034] As Figure 1As shown, a backpack type of reaction rectification column device, comprising a reaction rectification column 1, a partition heating assembly 2, a liquid buffer assembly 3, a reboiler 4, an evaporator 5, a cooling fractionating column 6, a steam permeation membrane unit 7 and a condenser 8, the reaction rectification column 1 is provided with a rectification section 11, an upper reaction section 12, a lower reaction section 13 and a stripping section 14 from top to bottom, the partition heating assembly 2 horizontally arranged in the middle of the reaction rectification column 1 separates the upper reaction section 12 and the lower reaction section 13 into two independent chambers, and the heating side of the partition heating assembly 2 is located at the bottom end of the upper reaction section 12;

[0035] The upper reaction section 12 is connected with the liquid buffer assembly 3 and the lower reaction section 13 in sequence through pipelines, and the liquid accumulated at the bottom of the upper reaction section 12 flows back to the stripping section 14 through the liquid buffer assembly 3 and the lower reaction section 13 in sequence;

[0036] The lower reaction section 13 is connected with the steam permeation membrane unit 7, the cooling fractionating column 6, the evaporator 5 and the upper reaction section 12 in sequence through pipelines, and the steam accumulated at the top of the lower reaction section 13 enters the stripping section 14 through the steam permeation membrane unit 7, the cooling fractionating column 6, the evaporator 5 and the upper reaction section 12 in sequence, and the target product and water are separated from the steam when the steam passes through the steam permeation membrane unit 7 and the cooling fractionating column 6 respectively, which destroys the balance of chemical reaction and promotes the forward progress of reaction;

[0037] The rectification section 11 is connected with the condenser 8 through a pipeline, and the steam after rectification enters the condenser 8 to generate liquid through a pipeline, and part of the liquid flows back to the rectification section 11 through a pipeline, and the other part of the liquid is discharged for collection;

[0038] The reboiler 4 is connected with the stripping section 14 through a pipeline, and completes the heating operation of the liquid in the stripping section 14.

[0039] Specifically, the liquid buffer assembly 3 comprises a buffer tank 31 and a pump 32, the inlet end of the buffer tank 31 is connected with the liquid outlet of the upper reaction section 12 through a pipeline, and the outlet end of the buffer tank 31 is connected with the liquid inlet of the lower reaction section 13 through a pipeline and the pump 32, which completes the storage and transportation of the liquid accumulated at the bottom of the upper reaction section 12 back to the lower reaction section 13.

[0040] Specifically, the cooling fractionating column 6, the steam permeation membrane unit 7 and the evaporator 5 are located outside the reaction rectifying column 1 to form a backpack type structure, the steam permeation membrane unit 7 is provided with a steam inlet 71, a retentate outlet 72 and a permeate outlet 73, the steam inlet 71 is connected with the steam outlet at the top of the lower reaction section 13 through a pipeline, the retentate outlet 72 is connected with the inlet of the cooling fractionating column 6 through a pipeline, the steam entering the steam permeation membrane unit 7 removes the target components under the driving force of the pressure difference between the inside and outside of the membrane, the removed target components are output from the permeate outlet 73 for collection, and other components are output through the retentate outlet 72 into the cooling fractionating column 6.

[0041] Specifically, the steam permeation membrane unit 7 adopts a steam permeation membrane, and the steam permeation membrane component is filled with a tubular, hollow fiber or plate and frame type membrane, and the material is selected from a molecular sieve membrane, amorphous silica membrane, chitosan membrane, PVA membrane or sodium alginate membrane.

[0042] Specifically, the steam permeation membrane unit is composed of 1 to 100 steam permeation membrane separators connected in series, in parallel or in a mixed manner.

[0043] Specifically, the cooling fractionating column 6 is provided with a plurality of fractionating collection pipes 61 for collecting liquid products condensed at different boiling points, and each fractionating collection pipe 61 is provided with a temperature measuring module 62 and a valve 63, the fractionating collection pipe 61 generating the corresponding secondary reaction product is connected with the evaporator 5 through a pipeline, and the generated condensed water is discharged from the corresponding fractionating collection pipe 61 for collection.

[0044] Specifically, the outlet end of the evaporator 5 is connected with the upper reaction section 12 through a pipeline, and the liquid vaporized through the evaporator 5 enters the upper reaction section 12 through a pipeline.

[0045] Specifically, the separation heating component 2 includes a separation plate and a heating plate, the inside of the separation plate is provided with an open cavity, and the heating plate is embeddedly installed in the inner cavity of the separation plate.

[0046] Specifically, the reaction rectifying column 1 is provided with at least one feed inlet 15. Specifically, a plurality of feed inlets 15 are uniformly arranged on the reaction rectifying column 1, when multiple raw materials are fed separately, the positions of the feed inlets should be determined according to the light and heavy components, and the heavy components are fed into the feed inlets above the reaction rectifying column 1, and the light components are fed into the feed inlets below the reaction rectifying column 1.

[0047] Specifically, a use method of a backpack type in-tower reaction rectifying device includes the following steps:

[0048] Step one, the raw material enters into the reaction rectification tower 1 through the feeding port 15, and the raw material in the stripping section 14 is changed into the gas phase component after the stripping operation and rises into the lower reaction section 13 to occur the reversible chemical reaction;

[0049] Step two, the gas phase component after the reaction enters into the vapor permeation membrane unit 7, and the target component is removed under the driving force of the pressure difference between the inside and outside of the membrane, thereby breaking the balance of the reversible chemical reaction and promoting the forward chemical reaction; at the same time, the removed target component is output and collected from the permeation side outlet 73, and other components are output into the cooling fractionation tower 6 through the retentate side outlet 72;

[0050] Step three, the gas phase component entering into the cooling fractionation tower 6 is cooled and condensed at different temperatures, and the mixed gaseous component is gradually separated into liquid phase products of different components; the fractionation collection pipe 61 generating the secondary reaction product is connected with the inlet of the evaporator through the pipeline, and the generated condensed water is discharged and collected from the corresponding fractionation collection pipe 61, thereby further removing the chemical reaction product and promoting the forward chemical reaction;

[0051] Step four, the liquid phase product entering into the evaporator 5 is changed into the gas phase component again at high temperature and enters into the upper reaction section 12 together with the gaseous component not liquefied in the cooling fractionation tower 6 to continue the chemical reaction; the heating plate in the separation heating assembly 2 provides heat for the second chemical reaction, and the gaseous component after the reaction rises to the rectification section 11 to start the rectification separation and is cooled into the liquid phase product by the condenser 8; part of the liquid phase product is refluxed into the upper reaction section 12, and the other part is collected as the tower top product;

[0052] Step five, the liquid refluxed into the upper reaction section 12 is refluxed into the stripping section 14 through the buffer tank 31 and the pump 32; part of the liquid in the stripping section 14 becomes the tower bottom product, and the other part is vaporized by the reboiler 4 to be refluxed.

[0053] Specifically, the reaction system is suitable for the reaction limited by the balance and the reaction forming the azeotrope.

[0054] It should be noted that, in this text, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between the entities or operations. Moreover, the terms “include”, “contain” or any other variant thereof are intended to cover the non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment.

[0055] The above-described embodiments are merely intended to describe the preferred modes of the present application, and are not intended to limit the scope of the present application. Various modifications and improvements of the present application made by those skilled in the art based on the above-described embodiments should fall within the scope of the present application defined by the claims.

Claims

1. A backpack-type in-tower reactive distillation apparatus, characterized in that: The system includes a reactive distillation column (1), a partitioned heating assembly (2), a liquid buffer assembly (3), a reboiler (4), an evaporator (5), a cooling fractionation column (6), a vapor permeation membrane unit (7), and a condenser (8). The reactive distillation column (1) is provided with a rectification section (11), an upper reaction section (12), a lower reaction section (13), and a stripping section (14) from top to bottom. The partitioned heating assembly (2) is horizontally arranged in the middle of the reactive distillation column (1) to separate the upper reaction section (12) and the lower reaction section (13) into two independent chambers. The heating side of the partitioned heating assembly (2) is located at the bottom of the upper reaction section (12). The upper reaction section (12) is connected to the liquid buffer assembly (3) and the lower reaction section (13) in sequence through pipes. The liquid accumulated at the bottom of the upper reaction section (12) flows back to the stripping section (14) in sequence through the liquid buffer assembly (3) and the lower reaction section (13). The lower reaction section (13) is connected in sequence to the vapor permeation membrane unit (7), the cooling fractionation tower (6), the evaporator (5), and the upper reaction section (12) through pipelines. The gas accumulated at the top of the lower reaction section (13) passes through the vapor permeation membrane unit (7), the cooling fractionation tower (6), the evaporator (5), and the upper reaction section (12) in sequence to enter the rectification section (11). When the gas passes through the vapor permeation membrane unit (7) and the cooling fractionation tower (6), the target product and water are separated, which disrupts the chemical reaction balance and promotes the forward reaction. The rectification section (11) is connected to the condenser (8) through a pipe. The gas after rectification enters the condenser (8) through the pipe to generate liquid. A portion of the liquid flows back into the rectification section (11) through the pipe, and the other portion of the liquid is discharged and collected. The reboiler (4) is connected to the stripping section (14) via a pipe and performs the heating operation of the liquid in the stripping section (14); The cooling fractionation tower (6), the vapor permeation membrane unit (7), and the evaporator (5) are all located outside the reactive distillation tower (1) to form a backpack-like structure. The vapor permeation membrane unit (7) is provided with a gas inlet (71), a stagnation side outlet (72), and a permeation side outlet (73). The gas inlet (71) is connected to the gas outlet at the top of the lower reaction section (13) through a pipe. The stagnation side outlet (72) is connected to the inlet of the cooling fractionation tower (6) through a pipe. The gas entering the vapor permeation membrane unit (7) completes the removal of the target component under the driving force of the pressure difference inside and outside the membrane. The removed target component is output and collected from the permeation side outlet (73), and other components are output into the cooling fractionation tower (6) through the stagnation side outlet (72). The cooling distillation tower (6) is equipped with multiple distillation collection pipes (61) for collecting liquid products condensed at different boiling points. Each distillation collection pipe (61) is equipped with a temperature measuring module (62) and a valve (63). The distillation collection pipe (61) that generates the corresponding secondary reaction product is connected to the evaporator (5) through a pipe. The generated condensate is discharged from the corresponding distillation collection pipe (61) and collected. The outlet end of the evaporator (5) is connected to the upper reaction section (12) through a pipe, and the liquid vaporized by the evaporator (5) enters the upper reaction section (12) through the pipe.

2. The backpack-type in-tower reactive distillation apparatus according to claim 1, characterized in that: The liquid buffer assembly (3) includes a buffer tank (31) and a pump (32). The inlet end of the buffer tank (31) is connected to the liquid outlet of the upper reaction section (12) through a pipe. The outlet end of the buffer tank (31) is connected to the liquid inlet of the lower reaction section (13) through a pipe and the pump (32), thus completing the operation of storing the liquid accumulated at the bottom of the upper reaction section (12) and transporting it back to the lower reaction section (13).

3. The backpack-type in-tower reactive distillation apparatus according to claim 1, characterized in that: The partition heating assembly (2) includes a partition plate and a heating plate. The interior of the partition plate is configured as a cavity with one end open, and the heating plate is embedded in the cavity of the partition plate.

4. The backpack-type in-tower reactive distillation apparatus according to claim 1, characterized in that: The reactive distillation column (1) is provided with at least one feed inlet (15).

5. A method of using a backpack-type in-column reactive distillation apparatus, characterized in that: A backpack-type in-column reactive distillation apparatus according to any one of claims 1-4 includes the following steps: Step 1: The raw material enters the reactive distillation column (1) through the feed inlet (15). After the raw material in the stripping section (14) is stripped, it becomes a gaseous component and rises into the lower reaction section (13) where a reversible chemical reaction occurs. Step 2: After the reaction occurs, the gaseous components enter the vapor permeate membrane unit (7). Under the driving force of the pressure difference between the inside and outside of the membrane, the gaseous components complete the removal of the target components, thereby disrupting the equilibrium of the reversible chemical reaction and promoting the forward reaction. At the same time, the removed target components are output and collected from the permeate side outlet (73), while other components are output through the retention side outlet (72) and enter the cooling fractionation tower (6). Step 3: The gaseous components entering the cooling fractionation tower (6) are cooled and condensed at different temperatures. The mixed gaseous components are gradually separated into liquid products of different components. The fractionation collection pipe (61) that generates the corresponding secondary reaction products is connected to the inlet of the evaporator through a pipe. At the same time, the generated condensate is discharged from the corresponding fractionation collection pipe (61) for collection, further removing the products generated by the chemical reaction and promoting the forward progress of the chemical reaction. Step 4: The liquid product entering the evaporator (5) is converted back into a gaseous component at high temperature. It is then transported through a pipeline to the upper reaction section (12) along with the unliquefied gaseous component in the cooling fractionation tower (6) to continue the chemical reaction. The heating plate in the separating heating component (2) provides heat for the second chemical reaction. The gaseous component after the reaction rises to the rectification section (11) to begin rectification and separation. It is then cooled into a liquid product by the condenser (8). Part of the liquid product is returned to the upper reaction section (12), while the other part is collected to become the top product of the tower. Step 5: The liquid refluxed into the upper reaction section (12) is refluxed into the stripping section (14) through the buffer tank (31) and pump (32). Part of the liquid in the stripping section (14) becomes the bottom product of the tower, and the other part is vaporized and refluxed through the reboiler (4).

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