Energy-coupled butyl acrylate production system

Abstract

The utility model belongs to the field of fine chemical synthesis, and particularly relates to an energy-coupled butyl acrylate continuous production system. According to the specific technical scheme, the method comprises the steps of raw material preheating coupling in an esterification reaction system, energy coupling of a catalyst recovery material, energy coupling of a product refining system and evaporation recovery of heavy components. The energy in the production system is fully coupled, the energy consumption and material consumption in the butyl acrylate production process can be obviously reduced, the raw material consumption is reduced, and the production cost is further reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of fine chemical production, and particularly relates to a continuous production system for butyl acrylate with energy coupling. Background Art

[0002] Butyl acrylate is a very important fine chemical intermediate. Because it has α carbon-carbon double bond and ester bond, it has relatively strong activity and is widely used in homopolymerization and copolymerization reactions to produce synthetic resins, synthetic fibers, synthetic rubbers, plastics, coatings, adhesives, etc. The traditional production method of butyl acrylate is obtained by direct esterification of acrylic acid and n-butanol in the presence of a catalyst, and the final product is obtained mainly through steps such as reaction, catalyst recovery, neutralization and water washing, light component removal and heavy component removal. CN106278882A provides a production system and method for butyl acrylate without alkali neutralization. The system includes a first reaction kettle, a second reaction kettle, an extraction tower, an azeotropic distillation tower, a light component removal tower and a dehydration tower. Among them, the first reaction kettle, the second reaction kettle and the extraction tower are connected in sequence. The overhead material outlet of the extraction tower is connected to the material inlet of the azeotropic distillation tower. The overhead material outlet of the azeotropic distillation tower is connected to the material inlet of the light component removal tower. The bottom material outlet of the azeotropic distillation tower and the bottom material outlet of the extraction tower are connected to the material inlet of the first reaction kettle. The overhead material outlet of the light component removal tower is connected to the material inlet of the dehydration tower. The bottom material outlet of the light component removal tower is connected to a heavy component removal tower outside the system. The bottom material outlet of the dehydration tower is connected to the material inlet of the first reaction kettle. The present invention transforms the neutralization tower in the traditional acrylic acid production process into an azeotropic distillation tower, without neutralization operation, and will not produce salty wastewater, which is more environmentally friendly. CN102249913A completes the synthesis method of butyl acrylate in a reactive distillation column, and at the same time completes the separation of the product and the raw materials through azeotropic distillation. At the same time, the heavy components generated by the reaction are decomposed into raw materials and products in the stripping section and the tower kettle, and finally an organic phase rich in butyl acrylate with an acrylic acid content of 4 ppm is obtained at the top of the tower. CN111099998A discloses a batch production process system for butyl acrylate. Acrylic acid, n-butanol, hydroquinone and a catalyst are added to a reaction kettle, and the temperature is raised for esterification reaction; the water, butyl acrylate and raw materials acrylic acid and n-butanol generated in the reaction undergo azeotropy and are evaporated from the reaction kettle to a condenser. The liquefied mixed liquid enters the dehydration tower, and the liquid after dehydration is re-transported back to the reaction kettle; the reaction end point is judged by sampling and detecting the water content value of the mixed liquid after condensation; when the water content value is less than 0.05%, the reaction is stopped, and the obtained crude butyl acrylate is transferred to an extraction tower for the next step of production.

[0003] Either of these methods is either a batch process, or has excessive energy consumption and material consumption, increasing the carbon emission equivalent in the production process. Content of the Utility Model

[0004] The technical problem to be solved by the present utility model is to provide a continuous production method for butyl acrylate with energy coupling, which cascades the energy in the reaction and separation processes of butyl acrylate to reduce energy consumption.

[0005] The technical solution proposed by the present utility model is as follows:

[0006] A continuous production system for butyl acrylate with energy coupling, including a first esterification reactor, a second esterification reactor, a n-butanol dehydration tower, a dehydration tower condenser, a dehydration tower top reflux drum, an acrylic acid coupling preheater, a butanol coupling preheater, a reaction material cooler, a catalyst extraction and recovery tower, a neutralization and washing tower, a crude ester buffer tank, a crude ester coupling preheater, a light component removal tower, a light component removal tower condenser, a light component removal tower reflux drum, a heavy component removal tower, a heavy component removal tower condenser, a heavy component removal tower reflux drum, a heavy component evaporator, an alcohol recovery tower, an alcohol recovery tower condenser, an alcohol recovery tower reflux drum, a product tank and other main equipment, as well as pipelines connecting the equipment.

[0007] More specifically, the dehydration tower, the first esterification reactor, the second esterification reactor, the butanol coupling preheater, the acrylic acid coupling preheater, the catalyst extraction and recovery tower, the neutralization and washing tower, the light component removal tower and the heavy component removal tower are connected in sequence through pipelines; the raw material acrylic acid is connected to the inlet of the first esterification reactor through a pipeline after passing through the acrylic acid coupling preheater, and the raw material n-butanol enters the n-butanol dehydration tower through a pipeline after passing through the butanol coupling preheater; the top of the n-butanol dehydration tower is connected to its condenser and reflux drum in sequence through a pipeline, the light phase outlet of the reflux drum is connected to the n-butanol dehydration tower through a pipeline to form a reflux, and the heavy phase outlet is connected to the upper inlet of the catalyst extraction and recovery tower and the inlet of the alcohol recovery tower in sequence through a pipeline, and a waste water outlet pipeline is provided at the bottom of the alcohol recovery tower; the bottom heavy phase outlet of the catalyst extraction and recovery tower is connected to the first esterification reactor through a pipeline; a softened water inlet pipeline is provided at the upper part of the neutralization and washing tower, and the bottom of the neutralization and washing tower is connected to the inlet of the alcohol recovery tower through a pipeline; the upper outlet of the neutralization and washing tower, the crude ester buffer tank, the crude ester coupling preheater and the light component removal tower are connected through pipelines; condensers corresponding to the tops of the light component removal tower and the heavy component removal tower and reflux drums corresponding to the tops are connected respectively, and the butyl acrylate product from the reflux drum at the top of the heavy component removal tower is connected to the product tank through a pipeline; the bottom outlet of the heavy component removal tower is connected to the inlet of the heavy component evaporator through a pipeline, the top outlet of the heavy component evaporator is connected to the lower gas phase inlet of the heavy component removal tower through a pipeline, and the heavy component evaporator is connected with a heat transfer oil heating pipeline.

[0008] Preferably, a sodium hydroxide solution inlet pipeline is provided in the middle of the neutralization and washing tower.

[0009] Preferably, a steam condensate inlet pipeline is provided for the crude ester coupling preheater.

[0010] Preferably, as environmental protection facilities, each top condenser of the n-butanol dehydration tower, light component removal tower and heavy component removal tower is provided with an exhaust gas outlet pipe, which is connected to the exhaust gas treatment facility through the main exhaust gas pipe.

[0011] Preferably, the pipeline between the crude ester buffer tank and the crude ester coupling preheater is directly connected. By utilizing the elevation difference and pressure difference between the crude ester buffer tank and the light component removal tower, there is no need to set up a pump, saving power consumption.

[0012] Preferably, the pipeline between the first esterification reactor and the second esterification reactor is directly connected, and there is no need to set up a pump.

[0013] Preferably, pumps are added to other pipelines that cannot rely on the gravity difference or pressure difference to achieve material transportation.

[0014] Compared with the prior art, the utility model has the following beneficial effects:

[0015] By setting up the n-butanol coupling preheater and the acrylic acid coupling preheater, heat exchange is carried out between the discharged materials of the second esterification reactor and the raw materials n-butanol and acrylic acid respectively, realizing the comprehensive utilization of low-quality reaction heat, and ensuring that the preheated acrylic acid does not exceed the temperature, which not only reduces the energy consumption of the device production, but also reduces the risk of acrylic acid polymerization; 2. By setting up the crude ester coupling preheater, heat exchange is carried out with the condensed water of the heating steam of the reboiler at the bottom of each distillation column, ensuring that the crude ester does not undergo a phase change during the preheating period and reducing polymerization, and at the same time, the heat of the condensed water can be comprehensively utilized, reducing the reboiler heat load of the light component removal tower and reducing the energy consumption of the device; 3. By setting up the heavy component evaporator, the butyl acrylate component in the rectified heavy component is further separated and stripped, reducing the heavy component discharge amount, thereby reducing the raw material consumption of butyl acrylate production.

[0016] Taking a 100,000-ton / year butyl acrylate production device as an example, through the setting of the utility model, acrylic acid and butanol can be heated from the normal temperature (20°C) to 50°C, saving 4,400 tons of steam per year; by setting up the crude ester coupling preheater and utilizing the waste heat of the condensate, the crude ester can be heated from 25°C to 75°C, saving 5,400 tons of steam per year. By setting up the heavy component evaporator, 2,000 tons of butyl acrylate products can be recovered every year, reducing the discharge and carbon emissions of heavy components. Brief Description of the Drawings

[0017] Attached Figure 1 is a schematic structural diagram of the continuous production system of butyl acrylate with energy coupling of the utility model.

[0018] The serial numbers and codes in the figure correspond to the equipment and pipelines as follows:

[0019] Acrylic acid coupling preheater; 2-butanol coupling preheater; 3-first esterification reactor; 4-second esterification reactor; 5-butanol dehydration tower; 6-catalyst extraction and recovery tower; 7-neutralization and washing tower; 8-crude ester buffer tank; 9-crude ester coupling preheater; 10-light component removal tower; 11-heavy component removal tower; 12-butanol dehydration tower condenser; 13-butanol dehydration tower reflux drum; 14-alcohol recovery tower; 15-heavy component removal tower reflux drum; 16-product tank; 17-heavy component evaporator; 18-light component removal tower condenser; 19-light component removal tower reflux drum; 20-heavy component removal tower condenser; 21-light component removal tower reboiler.

[0020] S1-raw material acrylic acid pipeline; S2-raw material n-butanol pipeline; S3-sodium hydroxide solution pipeline; S4-softened water pipeline; S5-waste water outlet pipeline; S6-butanol dehydration tower condenser waste gas pipeline; S7-light component removal tower condenser waste gas pipeline; S8-heavy component removal tower condenser waste gas pipeline; S9-waste gas main pipeline; S10-heavy component discharge pipeline. Detailed implementation manners

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0022] Embodiment 1

[0023] As Figure 1As shown in the figure, this embodiment provides a continuous production system for butyl acrylate with energy coupling, which is characterized in that: the raw material acrylic acid passes through the acrylic acid coupling preheater (1) through a pipeline and then connects to the inlet of the first esterification reactor (3), and the raw material n-butanol enters the n-butanol dehydration tower (5) after passing through the n-butanol coupling preheater (2) through a pipeline; the n-butanol dehydration tower (5), the first esterification reactor (3), the second esterification reactor (4), the n-butanol coupling preheater (2), the acrylic acid coupling preheater (1), the catalyst extraction and recovery tower (6), the neutralization and washing tower (7), the crude ester buffer tank (8), the crude ester coupling preheater (9), the light component removal tower (10) and the heavy component removal tower (11) are connected in sequence through pipelines: the top of the n-butanol dehydration tower (5) is connected to the n-butanol dehydration tower condenser (12) and the n-butanol dehydration tower reflux tank (13) in sequence through a pipeline, the light phase outlet of the reflux tank (13) is connected to the n-butanol dehydration tower (5) through a pipeline to form a reflux, and the heavy phase outlet is connected to the catalyst extraction and recovery tower (6) and the alcohol recovery tower (14) in sequence through a pipeline, and a waste water outlet pipeline (S5) is provided at the bottom of the alcohol recovery tower (14); the bottom heavy phase outlet of the catalyst recovery tower (6) is connected to the first esterification reactor (3) through a pipeline; a softened water inlet pipeline (S4) is provided at the upper part of the neutralization and washing tower (7), and the bottom of the neutralization and washing tower (7) is connected to the inlet of the alcohol recovery tower (14) through a pipeline; the upper outlet of the neutralization and washing tower (7) is connected to the crude ester buffer tank (8), and the crude ester buffer tank (8), the crude ester coupling preheater (9) and the light component removal tower (10) are connected through a pipeline; condensers corresponding to the tops of the light component removal tower (10) and the heavy component removal tower (11) are connected respectively, and corresponding top reflux tanks are connected respectively. The butyl acrylate product of the top reflux tank (15) of the heavy component removal tower is connected to the product tank (16) through a pipeline; the bottom outlet of the heavy component removal tower is connected to the inlet of the heavy component evaporator (17) through a pipeline, and the top outlet of the heavy component evaporator (17) is connected to the lower gas phase inlet of the heavy component removal tower (11) through a pipeline.

[0024] Specific working process:

[0025] The raw material acrylic acid at normal temperature enters the first esterification reactor 3 after being preheated by the coupling preheater 1 (temperature 51°C). The raw material n-butanol at normal temperature enters the n-butanol dehydration tower 5 after being preheated by the coupling preheater 2 (temperature 52°C). Under the action of the alcohol, acrylic acid and the catalyst benzenesulfonic acid / p-toluenesulfonic acid in the bottom material of the dehydration tower 5, the esterification reaction is carried out successively in the first esterification reactor 3 (temperature 90 - 100°C) and the second esterification reactor 4 (temperature 90 - 100°C). The top of the n-butanol dehydration tower 5 passes through the n-butanol dehydration tower condenser 12 and the n-butanol dehydration tower reflux drum 13. The light-phase outlet of the reflux drum 13 is connected to the n-butanol dehydration tower 5 through a pipeline to form a reflux, and the heavy-phase outlet is connected to the catalyst extraction and recovery tower 6 and the alcohol recovery tower 14 in sequence through a pipeline; the material discharged from the second esterification reactor 4 enters the catalyst extraction and recovery tower 6 after passing through the n-butanol coupling preheater 2 and the acrylic acid coupling preheater 1; the bottom heavy-phase outlet of the catalyst recovery tower 6 is connected to the first esterification reactor 3 through a pipeline; the top of the catalyst recovery tower 6 goes to the neutralization and washing tower 7; the upper part of the neutralization and washing tower 7 is provided with a softened water inlet pipeline S4 and a sodium hydroxide inlet pipeline S3; the bottom liquid of the neutralization and washing tower 7 goes to the alcohol recovery tower 14; the bottom of the alcohol recovery tower 14 is provided with a waste water outlet pipeline S5; the upper outlet of the neutralization and washing tower 7 is connected to the crude ester buffer tank 8, and the crude ester coupling preheater 9 and the light component removal tower 10 are connected through a pipeline. The outlet temperature of the crude ester coupling preheater is controlled at 70 - 80°C; the tops of the light component removal tower 10 and the heavy component removal tower 11 are both connected with corresponding top condensers and corresponding top reflux drums; the bottom of the light component removal tower 10, the light component tower reboiler 21, uses steam condensate to return to the crude ester coupling preheater 9 for thermal coupling; the bottom material of the light component removal tower 10 enters the heavy component removal tower 11; the final product of butyl acrylate in the top reflux drum 15 of the heavy component removal tower is connected to the product tank 16 through a pipeline; the bottom outlet of the heavy component removal tower is connected to the inlet of the heavy component evaporator 17 through a pipeline, the top outlet of the heavy component evaporator 17 is connected to the lower gas-phase inlet of the heavy component removal tower 11 through a pipeline, and the bottom heavy components are discharged out of the battery limit.

Claims

1. Energy-coupled butyl acrylate continuous production system, characterized by: The raw material acrylic acid passes through an acrylic acid coupling preheater (1) through a pipeline and is connected to the inlet of a first esterification reactor (3); the raw material n-butanol passes through an n-butanol coupling preheater (2) through a pipeline and enters an n-butanol dehydration tower (5); the n-butanol dehydration tower (5), the first esterification reactor (3), the second esterification reactor (4), the n-butanol coupling preheater (2), the acrylic acid coupling preheater (1), the catalyst extraction recovery tower (6), the neutralization washing tower (7), the crude ester buffer tank (8), the crude ester coupling preheater (9), the light component removal tower (10) and the heavy component removal tower (11) are sequentially connected through pipelines; the top of the n-butanol dehydration tower (5) is sequentially connected to an n-butanol dehydration tower condenser (12) and an n-butanol dehydration tower reflux tank (13) through a pipeline; the light phase outlet of the reflux tank (13) is connected to the n-butanol dehydration tower (5) through a pipeline to form a reflux, and the heavy phase outlet is sequentially connected to the catalyst extraction recovery tower (6) and the alcohol reflux tank (13) through a pipeline. The collection tower (14) and the alcohol recovery tower (14) are provided with a wastewater outlet pipeline at the bottom; the heavy phase outlet at the bottom of the catalyst extraction recovery tower (6) is connected to the first esterification reactor (3) through a pipeline; the upper part of the neutralization washing tower (7) is provided with a softened water inlet pipeline, and the bottom of the neutralization washing tower (7) is connected to the inlet of the alcohol recovery tower (14) through a pipeline; the upper outlet of the neutralization washing tower (7), the crude ester buffer tank (8), the crude ester coupling preheater (9) and the light component removal tower (10) are connected through a pipeline; the tops of the light component removal tower (10) and the heavy component removal tower (11) are both connected to corresponding tower top condensers and corresponding tower top reflux tanks, and the butyl acrylate product of the tower top reflux tank (15) of the heavy component removal tower is connected to the product tank (16) through a pipeline; the tower kettle outlet of the heavy component removal tower (11) is connected to the inlet of the heavy component evaporator (17) through a pipeline, and the top outlet of the heavy component evaporator (17) is connected to the lower gas phase inlet of the heavy component removal tower (11) through a pipeline.

2. The energy-coupled butyl acrylate continuous production system according to claim 1, characterized in that: The crude ester coupling preheater (9) is provided with a steam condensate inlet pipe.

3. The energy-coupled butyl acrylate continuous production system according to claim 2, characterized in that: The outlet pipeline of the second esterification reactor (4) is connected to the n-butanol coupling preheater (2) and the acrylic acid coupling preheater (1) in sequence.

4. The energy-coupled butyl acrylate continuous production system according to claim 3, characterized in that: The outlet pipeline of the kettle of the heavy component removal tower (11) is connected to the inlet of the heavy component evaporator (17), and the heavy component evaporator (17) is connected to a heat transfer oil heating pipeline.

5. The energy-coupled butyl acrylate continuous production system according to claim 2, characterized in that: A sodium hydroxide solution inlet pipe is arranged in the middle of the neutralization washing tower (7).

6. The energy-coupled butyl acrylate continuous production system according to claim 2, characterized in that: The crude ester buffer tank (8) and the crude ester coupling preheater (9) are directly connected by pipelines, and no pump is required.

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