Acrylic acid oxidation device

Abstract

The utility model belongs to the technical field of chemical equipment, and particularly relates to an acrylic acid oxidation device. The acrylic acid oxidation device comprises a propylene evaporator, a first oxidation reactor, a second oxidation reactor and a quenching absorption tower, the propylene evaporator is connected with a mixer a, the mixer a is connected with the first oxidation reactor, the first oxidation reactor is connected with a mixer c, and the mixer c is connected with the second oxidation reactor. The second oxidation reactor is connected with a quenching absorption tower, the first oxidation reactor is connected with a heat exchanger a through a fused salt circulating pump, the heat exchanger a is connected with a high-pressure steam buffer tank, the second oxidation reactor is connected with a heat exchanger d through a heat medium oil circulating pump, and the heat exchanger d is connected with the high-pressure steam buffer tank. According to the acrylic acid oxidation device provided by the utility model, the yield and the purity of acrylic acid can be improved, and meanwhile, energy consumption and environmental pollution are reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical equipment, and specifically relates to an acrylic acid oxidation device. Background Art

[0002] Acrylic acid is an unsaturated organic acid with a carbon-carbon double bond and a carboxyl structure in the molecule, from which various products are derived. Acrylic acid plays an important role in industrial development. It not only has excellent polymerization and esterification capabilities, but also can provide important intermediates for the synthesis of fine chemicals.

[0003] At present, the more traditional production methods of acrylic acid mainly include the chlorohydrin method, the cyanohydrin method, the high-pressure method, and the direct oxidation method of propylene. The direct oxidation method is to catalyze the reaction raw materials containing propylene, water vapor and air to generate acrolein and part of acrylic acid, acetaldehyde and COX, and then acrolein is further converted into acrylic acid. Acrylic acid can be absorbed and distilled to obtain crude acrylic acid, and then refined to obtain high-purity acrylic acid. However, the traditional acrylic acid oxidation device has problems such as low reaction efficiency, high energy consumption, and serious environmental pollution.

[0004] CN214991236U discloses a complete set of acrylic acid production equipment by circulating propylene oxidation method, including a feed oxidation reaction unit, a circulating quenching absorption unit and a product refining unit. The liquid phase of the feed oxidation reaction unit is connected to the circulating quenching absorption unit through a pipeline, the gas phase at the top of the circulating quenching absorption unit is connected to the feed oxidation reaction unit through a pipeline, the liquid phase of the circulating quenching absorption unit is connected to the product refining unit through a pipeline, the product refining unit is provided with a discharge pipeline connected to the acrylic acid product tank area and outputs finished products, and the tail gas of the product refining unit is removed from the waste gas incineration treatment system. The utility model adopts a reactor for continuous reaction, and the tail gas realizes a circulating reaction, which increases the reaction depth and improves the product yield, but the heat energy is seriously wasted and the energy consumption is high. Utility Model Content

[0005] The technical problem to be solved by the utility model is to overcome the above-mentioned defects in the prior art and provide an acrylic acid oxidation device, which can improve the yield and purity of acrylic acid and reduce energy consumption and environmental pollution.

[0006] The acrylic acid oxidation device described in the utility model comprises a propylene evaporator, a first oxidation reactor, a second oxidation reactor, and a quenching absorption tower. The propylene evaporator is connected to a mixer a, the mixer a is connected to the first oxidation reactor, the first oxidation reactor is connected to a mixer c, the mixer c is connected to the second oxidation reactor, the second oxidation reactor is connected to the quenching absorption tower, the first oxidation reactor is connected to a heat exchanger a through a molten salt circulation pump, the heat exchanger a is connected to a high-pressure steam buffer tank, the second oxidation reactor is connected to a heat exchanger d through a heat medium oil circulation pump, and the heat exchanger d is connected to a high-pressure steam buffer tank. The propylene evaporator is mainly a kettle heat exchanger, which is used to gasify liquid propylene. The high-pressure steam buffer tank is a container for buffering the high-pressure steam generated by the device. The molten salt circulation pump is used to circulate the molten salt of the system through the heat removal medium of the system in the system to transfer the heat generated by the oxidation reaction. The heat exchanger a is a device for exchanging the heat brought out by the molten salt in the system with boiler water. The heat medium oil circulation pump is used to circulate the heat transfer oil of the system through the heat removal medium of the system in the system to transfer the heat generated by the oxidation reaction. Heat exchanger d is used to exchange heat brought out by the heat transfer oil in the second oxidation reactor system with boiler water.

[0007] Preferably, mixer a is connected to mixer b, and mixer b is connected to an air compressor. Mixer a is a device for mixing humidified air with gaseous propylene. Mixer b is used to mix air delivered by a blower with medium-pressure steam to form humidified air.

[0008] Preferably, the air compressor is connected to a driving turbine. The air compressor is a device that provides air for the reaction, and is usually a centrifugal blower. The driving turbine uses steam to drive a turbine to provide power for the air compressor.

[0009] Preferably, the outlet pipeline of the air compressor is connected to the mixer c. The mixer c is a device for mixing the outlet reaction gas of the first oxidation reactor with air.

[0010] Preferably, a water circulation pump is provided at the bottom of the first oxidation reactor, and the water circulation pump is connected to a cooler. A catalyst is provided in the first oxidation reactor, and under the action of the catalyst, propylene reacts with air to produce acrolein. The water circulation pump circulates boiler water of the outlet fin cooler of the first oxidation reactor. The cooler uses boiler water to exchange heat with the reaction gas at the outlet of the first oxidation reactor, and cools the reaction gas of the first oxidation reactor to a suitable temperature.

[0011] Preferably, a molten salt electric heater is provided on the first oxidation reactor. The molten salt electric heater is a molten salt electric heater of the first oxidation reactor, which is used to heat the molten salt in the system before starting to reach the start-up conditions.

[0012] Preferably, an electric heater is provided on the second oxidation reactor. The second oxidation reactor is used to mix the reaction gas from the first oxidation reactor with air and then pass through the catalyst bed to catalyze the reaction to produce acrylic acid. The electric heater is a device used to heat the heat transfer oil in the second oxidation reactor system before starting.

[0013] Preferably, a heat exchanger C is provided on the pipeline connecting the second oxidation reactor and the quenching absorption tower. The heat exchanger C is a shell-and-tube heat exchanger, which cools down the outlet reaction gas of the second oxidation reactor.

[0014] The quenching absorption tower cools and absorbs the reacted gas in the second oxidation reactor.

[0015] Preferably, a centrifugal pump is provided at the bottom of the quenching absorption tower, and the centrifugal pump is connected to the heat exchanger B. The centrifugal pump transports the material of the quenching absorption tower.

[0016] Preferably, the heat exchanger b is a spiral plate heat exchanger to cool the materials in the bottom of the tower.

[0017] The acrylic acid oxidation device of the utility model, when working, utilizes the propylene evaporator to gasify the liquid propylene, enters the mixer a for humidification, is mixed with the steam compressed by the air compressor and then mixed with the steam of the mixer b for humidification, enters the mixer a for mixing, enters the first oxidation reactor, the propylene reacts with the air under the action of the catalyst to generate acrolein, the generated acrolein enters the mixer c to mix with the air, and after mixing, enters the second oxidation reactor to continue to react, generates acrylic acid under the action of the catalyst, and enters the quenching absorption tower for cooling and absorption after heat exchange in the heat exchanger c, the heat generated by the reaction in the first oxidation reactor is removed by the molten salt circulation pump, the heat brought out is exchanged with the boiler water through the heat exchanger a, the generated high-pressure steam enters the high-pressure steam buffer tank for buffering, and similarly, the high-pressure steam generated in the second oxidation reactor is also entered into the high-pressure steam buffer tank for buffering after the heat exchange.

[0018] Compared with the prior art, the utility model has the following beneficial effects:

[0019] The acrylic acid oxidation device of the utility model recycles the heat energy generated by the first oxidation reactor and the second oxidation reactor, and the whole system has stable reaction, heat energy circulation, reduced energy consumption and improved benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the acrylic acid oxidation device of the utility model.

[0021] In the figure: 1. propylene evaporator; 2. mixer a; 3. mixer b; 4. high-pressure steam buffer tank; 5. molten salt circulation pump; 6. heat exchanger a; 7. first oxidation reactor; 8. molten salt electric heater; 9. mixer c; 10. heat medium oil circulation pump; 11. second oxidation reactor; 12. quenching absorption tower; 13. electric heater; 14. heat exchanger b; 15. centrifugal pump; 16. heat exchanger c; 17. heat exchanger d; 18. water circulation pump; 19. cooler; 20. air compressor; 21. drive turbine. DETAILED DESCRIPTION

[0022] The utility model is further described below in conjunction with specific embodiments.

[0023] like Figure 1 As shown, the acrylic acid oxidation device described in the utility model comprises a propylene evaporator 1, a first oxidation reactor 7, a second oxidation reactor 11, and a quenching absorption tower 12. The propylene evaporator 1 is connected to the mixer a2, the mixer a2 is connected to the first oxidation reactor 7, the first oxidation reactor 7 is connected to the mixer c9, the mixer c9 is connected to the second oxidation reactor 11, the second oxidation reactor 11 is connected to the quenching absorption tower 12, the first oxidation reactor 7 is connected to the heat exchanger a6 through the molten salt circulation pump 5, the heat exchanger a6 is connected to the high-pressure steam buffer tank 4, the second oxidation reactor 11 is connected to the heat exchanger d17 through the heat medium oil circulation pump 10, and the heat exchanger d17 is connected to the high-pressure steam buffer tank 4. The propylene evaporator 1 is mainly a kettle heat exchanger used to gasify liquid propylene. The high-pressure steam buffer tank 4 is used as a container for buffering the high-pressure steam generated by the device. The molten salt circulation pump 5 is used to circulate the heat removal medium molten salt in the system to transfer the heat generated by the oxidation reaction. Heat exchanger a6 is used to exchange heat brought out by the molten salt in the system with boiler water. Heat medium oil circulation pump 10 is used to circulate the heat transfer oil in the system through the heat removal medium of the system to transfer the heat generated by the oxidation reaction. Heat exchanger d17 is used to exchange heat brought out by the heat transfer oil in the oxidation second reactor 11 system with boiler water.

[0024] The mixer a2 is connected to the mixer b3, and the mixer b3 is connected to the air compressor 20. The mixer a2 is a device for mixing humidified air with gaseous propylene. The mixer b3 is a device for mixing air delivered by the fan with medium-pressure steam to form humidified air.

[0025] The air compressor 20 is connected to a driving turbine 21. The air compressor 20 is a device for providing air for the reaction, and is usually a centrifugal blower. The driving turbine 21 utilizes steam to drive a turbine to provide power for the air compressor.

[0026] The outlet pipeline of the air compressor 20 is connected to the mixer c9. The mixer c9 is a device for mixing the outlet reaction gas of the first oxidation reactor 7 with air.

[0027] A water circulation pump 18 is provided at the bottom of the first oxidation reactor 7, and the water circulation pump 18 is connected to a cooler 19. A catalyst is provided in the first oxidation reactor 7, and under the action of the catalyst, propylene reacts with air to produce acrolein. The water circulation pump 18 circulates the boiler water of the outlet fin cooler of the first oxidation reactor 7. The cooler 19 uses the boiler water to exchange heat with the reaction gas at the outlet of the first oxidation reactor 7, and cools the reaction gas of the first oxidation reactor 7 to a suitable temperature.

[0028] The first oxidation reactor 7 is provided with a molten salt electric heater 8. The molten salt electric heater 8 is a molten salt electric heater of the first oxidation reactor, and is a device used to heat the molten salt in the system before starting to reach the start-up conditions.

[0029] The second oxidation reactor 11 is provided with an electric heater 13. The second oxidation reactor 11 is used to mix the reaction gas from the first oxidation reactor 7 with air and then pass through the catalyst bed to catalyze the reaction to produce acrylic acid. The electric heater 13 is a device used to heat the heat transfer oil in the second oxidation reactor 11 system before starting.

[0030] A heat exchanger c16 is provided on the pipeline connecting the second oxidation reactor 11 and the quenching absorption tower 12. The heat exchanger c16 is a shell-and-tube heat exchanger, which cools down the outlet reaction gas of the second oxidation reactor 11.

[0031] The quenching absorption tower 12 cools and absorbs the reacted gas in the second oxidation reactor 11.

[0032] A centrifugal pump 15 is provided at the bottom of the quenching absorption tower 12, and the centrifugal pump 15 is connected to the heat exchanger b14. The centrifugal pump 15 transports the material of the quenching absorption tower 12.

[0033] The heat exchanger b14 is a spiral plate heat exchanger, which cools the materials in the bottom of the tower.

[0034] The acrylic acid oxidation device of the utility model, when working, utilizes the propylene evaporator 1 to gasify the liquid propylene, enters the mixer a2 for humidification, and is mixed with the steam compressed by the air compressor 20 and then mixed with the steam of the mixer b for humidification, and then enters the mixer a2 for mixing, and enters the first oxidation reactor 7, where the propylene reacts with the air under the action of the catalyst to generate acrolein, and the generated acrolein enters the mixer c and is mixed with the air, and then enters the second oxidation reactor 11 for continuous reaction, and generates acrylic acid under the action of the catalyst, and enters the quenching absorption tower for cooling and absorption after heat exchange in the heat exchanger c16, and the heat generated by the reaction in the first oxidation reactor 7 is removed by the molten salt circulation pump, and the heat brought out is exchanged with the boiler water through the heat exchanger a6, and the generated high-pressure steam enters the high-pressure steam buffer tank 4 for buffering, and similarly, after the heat generated by the second oxidation reactor 11 is exchanged, the high-pressure steam also enters the high-pressure steam buffer tank 4 for buffering.

Claims

1. An acrylic acid oxidation device, characterized in that: The invention comprises a propylene evaporator (1), a first oxidation reactor (7), a second oxidation reactor (11), and a quenching absorption tower (12). The propylene evaporator (1) is connected to a mixer a (2), the mixer a (2) is connected to the first oxidation reactor (7), the first oxidation reactor (7) is connected to a mixer c (9), the mixer c (9) is connected to the second oxidation reactor (11), the second oxidation reactor (11) is connected to the quenching absorption tower (12), the first oxidation reactor (7) is connected to a heat exchanger a (6) via a molten salt circulation pump (5), the heat exchanger a (6) is connected to a high-pressure steam buffer tank (4), the second oxidation reactor (11) is connected to a heat exchanger d (17) via a heat medium oil circulation pump (10), and the heat exchanger d (17) is connected to the high-pressure steam buffer tank (4).

2. The acrylic acid oxidation device according to claim 1, characterized in that: The mixer a (2) is connected to the mixer b (3), and the mixer b (3) is connected to the air compressor (20).

3. The acrylic acid oxidation device according to claim 2, characterized in that: The air compressor (20) is connected to the driving turbine (21).

4. The acrylic acid oxidation device according to claim 2, characterized in that: The outlet pipeline of the air compressor (20) is connected to the mixer c (9).

5. The acrylic acid oxidation device according to claim 1, characterized in that: A water circulation pump (18) is provided at the bottom of the first oxidation reactor (7), and the water circulation pump (18) is connected to a cooler (19).

6. The acrylic acid oxidation device according to claim 1, characterized in that: A molten salt electric heater (8) is provided on the first oxidation reactor (7).

7. The acrylic acid oxidation device according to claim 1, characterized in that: The second oxidation reactor (11) is provided with an electric heater (13).

8. The acrylic acid oxidation device according to claim 1, characterized in that: A heat exchanger c (16) is provided on the pipeline connecting the second oxidation reactor (11) and the quenching absorption tower (12).

9. The acrylic acid oxidation device according to claim 1, characterized in that: A centrifugal pump (15) is provided at the bottom of the quench absorption tower (12), and the centrifugal pump (15) is connected to the heat exchanger b (14).

10. The acrylic acid oxidation device according to claim 9, characterized in that: The heat exchanger b (14) is a spiral plate heat exchanger.

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