Acetaldehyde rectification device

Abstract

The utility model discloses an acetaldehyde rectification device, which belongs to the technical field of tail gas treatment and comprises an absorption tower, the absorption tower is connected with a dilute acetaldehyde storage tank through a pipeline, the dilute acetaldehyde storage tank is connected with a primary condenser through a pipeline, and the primary condenser is connected with a rectification tower through a pipeline and further connected with a primary return tank through a pipeline. The first-stage reflux tank is connected with the second-stage condenser through a pipeline; and the second-stage condenser is connected with the second-stage reflux tank through a pipeline. The acetaldehyde rectification device can solve the problems of high energy consumption, complex operation, low product purity and the like in the existing acetaldehyde rectification process, and the problems of environmental pollution, energy waste and limitation on the economic benefit and the product quality of acetaldehyde production due to the fact that a large amount of heat energy is consumed in the whole acetaldehyde rectification process and the rectified acetaldehyde gas is not fully utilized. The acetaldehyde recycling device can effectively improve acetaldehyde recycling efficiency, reduce acetaldehyde waste, reduce steam consumption, comprehensively utilize heat energy and reduce environmental pollution.

Description

Technical Field

[0001] The utility model relates to the technical field of tail gas treatment, in particular to an acetaldehyde distillation device. Background Art

[0002] Acetaldehyde, also known as acetic acid aldehyde, is a colorless, free-flowing liquid with a pungent odor. It has a melting point of -121°C, a boiling point of 20.8°C, and a relative density of less than 1. It is miscible with some organic substances such as water and ethanol, and is flammable and volatile. Acetaldehyde is an important organic chemical intermediate and has a wide range of uses in pesticides, medicines, food and feed additives, and other fields.

[0003] In existing industrial production, ethanol oxidation is commonly used to produce acetaldehyde. In the production process, distillation is a key step in purifying acetaldehyde. The energy consumption of distillation accounts for 50%-70% of the energy consumption of the entire separation process. However, the effective utilization rate of energy is very low. About 95% of the heat energy supplied to the distillation tower is converted into waste heat from the condensation phase change of the overhead steam.

[0004] The traditional acetaldehyde distillation process has problems such as high energy consumption, complex operation, and low product purity. The entire acetaldehyde distillation process consumes a large amount of heat energy, and the acetaldehyde gas after distillation is not fully utilized, causing environmental pollution and energy waste, limiting the economic benefits and product quality of acetaldehyde production. Utility Model Content

[0005] The purpose of the utility model is to provide an acetaldehyde distillation device, which can not only effectively improve the acetaldehyde recovery efficiency, reduce acetaldehyde waste, reduce steam consumption, and comprehensively utilize heat energy, but also reduce environmental pollution and solve the problems in the prior art.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] An acetaldehyde distillation device comprises an absorption tower, wherein the absorption tower is connected to a dilute acetaldehyde storage tank via a pipeline, the dilute acetaldehyde storage tank is connected to a primary condenser via a pipeline, the primary condenser is connected to a distillation tower via a pipeline, the primary condenser is also connected to a primary reflux tank via a pipeline, the primary reflux tank is connected to a secondary condenser via a pipeline, the secondary condenser is connected to a secondary reflux tank via a pipeline, and both the primary reflux tank and the secondary reflux tank are connected to a finished product tank via pipelines.

[0008] Preferably, the tail gas outlet of the dilute acetaldehyde storage tank is connected to the inlet of the absorption tower through a pipeline, and the acetaldehyde tail gas is circulated and absorbed again, wherein the absorption tower adopts a rotary nozzle for spraying to completely absorb the acetaldehyde gas from all directions.

[0009] Preferably, the top steam of the distillation tower enters the first reflux tank after heat exchange through the first condenser, the first reflux tank is connected to the second condenser, the incompletely liquefied acetaldehyde gas is condensed by the second condenser and stored in the second reflux tank.

[0010] Preferably, the primary condenser is a spiral tube heat exchanger, the secondary condenser is a cryogenic condensation heat exchanger, and the medium used is chilled brine.

[0011] Preferably, the primary reflux tank is a main reflux tank, and a liquid level meter is provided in the secondary reflux tank. When a certain amount is collected, the valve is opened and the liquid is pumped into the distillation tower through a pipeline for reflux.

[0012] Preferably, before entering the dilute acetaldehyde storage tank, the liquid first enters a primary condenser to exchange heat with the overhead steam of the distillation tower to increase its temperature, and then enters the distillation tower for vaporization.

[0013] Preferably, a circulation pump is provided on the side of the absorption tower, the water inlet of the circulation pump is connected to the bottom end of the absorption tower through a pipe, and the water outlet of the circulation pump is connected to the spray plate through a pipe. The spray plate is located on the inner side of the absorption tower, and the spray plate is located above the packing layer. The spray plate is provided with evenly distributed nozzles, and the nozzles completely absorb acetaldehyde gas from all directions through rotary spraying.

[0014] Preferably, a rotating shaft is provided on the spray disc, the rotating shaft is mounted on the absorption tower via a bearing, and the rotating shaft is rotated by a motor, wherein the motor is mounted on the outer wall of the absorption tower.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] The entire device of the utility model has a reasonable method, a simple structure, low cost and is easy to operate. The absorption tower can reduce the pollution of acetaldehyde tail gas to the environment and improve the acetaldehyde absorption efficiency. A two-stage condensing device is adopted to condense the tower top steam step by step, thereby improving the condensation efficiency and reducing energy consumption. A two-stage reflux device is adopted to improve the acetaldehyde recovery rate, which can not only effectively improve the acetaldehyde recovery efficiency, reduce acetaldehyde waste, reduce steam consumption, and comprehensively utilize heat energy, but also reduce environmental pollution. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic structural diagram of an acetaldehyde distillation device of the present invention;

[0018] Figure 2 This is a structural cross-sectional view of the absorption tower of the present utility model;

[0019] Figure 3 It is a partial enlarged view of the absorption tower of the present utility model;

[0020] Figure 4 This is a top cross-sectional view of the rotating shaft connected to the spray disc of the present invention.

[0021] In the figure: 1. Absorption tower; 11. Circulation pump; 12. Spray plate; 13. Nozzle; 14. Rotating shaft; 15. Packing layer; 2. Dilute acetaldehyde storage tank; 3. Distillation tower; 4. Primary condenser; 5. Primary reflux tank; 6. Secondary condenser; 7. Secondary reflux tank; 8. Finished product tank. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] In order to solve the problems of high energy consumption, complex operation and low product purity in the existing acetaldehyde distillation process, the entire acetaldehyde distillation process consumes a lot of heat energy and the acetaldehyde gas after distillation is not fully utilized, causing environmental pollution and energy waste, which limits the economic benefits of acetaldehyde production and product quality. Figure 1-Figure 4 , this embodiment provides the following technical solutions:

[0024] An acetaldehyde distillation device comprises an absorption tower 1, wherein the absorption tower 1 is connected to a dilute acetaldehyde storage tank 2 through a pipeline.

[0025] In this embodiment, the tail gas outlet of the dilute acetaldehyde storage tank 2 is connected to the inlet of the absorption tower 1 through a pipeline, so that the acetaldehyde tail gas is circulated and absorbed again.

[0026] Absorption tower 1 uses a rotary nozzle for spraying to completely absorb acetaldehyde gas from all directions.

[0027] A circulation pump 11 is provided on the side of the absorption tower 1. The water inlet of the circulation pump 11 is connected to the bottom end of the absorption tower 1 through a pipe, and the water outlet of the circulation pump 11 is connected to the spray plate 12 through a pipe. The spray plate 12 is located on the inner side of the absorption tower 1, and the spray plate 12 is located above the packing layer 15. The spray plate 12 is provided with evenly distributed nozzles 13. The nozzles 13 completely absorb acetaldehyde gas from all directions through rotary spraying.

[0028] The spray disc 12 is provided with a rotating shaft 14 , which is mounted on the absorption tower 1 via a bearing. The rotating shaft 14 is rotated by a motor, wherein the motor is mounted on the outer wall of the absorption tower 1 .

[0029] It should be noted that when the motor is started, the motor drives the rotating shaft 14 to rotate, causing the spray disc 12 to rotate as well. During the rotation of the spray disc 12, the nozzle 13 provided on the spray disc 12 can also be driven to rotate. The nozzle 13 can completely absorb acetaldehyde gas from all directions through a rotary spraying method, which can effectively solve the problem that most existing fixed nozzles cannot completely absorb acetaldehyde gas.

[0030] The dilute acetaldehyde storage tank 2 is connected to the primary condenser 4 through a pipeline, and the primary condenser 4 is connected to the distillation tower 3 through a pipeline.

[0031] In this embodiment, before entering the dilute acetaldehyde storage tank 2, the liquid first enters the primary condenser 4 to exchange heat with the top steam of the distillation tower 3 to increase its temperature, and then enters the distillation tower 3 for vaporization, making it easier to vaporize when entering the distillation tower 3, thereby improving the distillation efficiency of the distillation tower 3 and reducing the amount of steam consumed by the distillation tower 3.

[0032] The primary condenser 4 is also connected to the primary reflux tank 5 through a pipeline, the primary reflux tank 5 is connected to the secondary condenser 6 through a pipeline, and the secondary condenser 6 is connected to the secondary reflux tank 7 through a pipeline.

[0033] In this embodiment, the primary condenser 4 is a spiral tube heat exchanger, the secondary condenser 6 is a cryogenic condensation heat exchanger, and the medium used is refrigerated brine.

[0034] In this embodiment, the top steam of the distillation tower 3 enters the first-level reflux tank 5 after heat exchange through the first-level condenser 4, and the first-level reflux tank 5 is connected to the second-level condenser 6. The acetaldehyde gas that is not completely liquefied is condensed by the second-level condenser 6 and stored in the second-level reflux tank 7, thereby improving the acetaldehyde production efficiency.

[0035] In this embodiment, the primary reflux tank 5 is the main reflux tank, and a liquid level meter is provided in the secondary reflux tank 7. When a certain amount of liquid is collected, the valve is opened and the liquid is pumped into the distillation tower 3 through a pipeline for reflux.

[0036] The primary reflux tank 5 and the secondary reflux tank 7 are both connected to the finished product tank 8 through pipelines.

[0037] Working principle: after the synthesized acetaldehyde gas is absorbed by the absorption tower 1, it enters the dilute acetaldehyde storage tank 2, and the tail gas from the dilute acetaldehyde storage tank 2 enters the absorption tower 1 for cyclic absorption. After the dilute acetaldehyde is heat exchanged with the primary condenser 4, it is pumped into the distillation tower 3 for distillation. The top gas of the distillation tower 3 is cooled by the primary condenser 4 and enters the primary reflux tank 5. The primary reflux tank 5 is connected to the secondary reflux tank 7. A secondary condenser 6 is provided in the middle of the pipeline. The condensed liquid in the primary reflux tank 5 and the secondary reflux tank 7 can be pumped into the distillation tower 3 through the pipeline for reflux. After the product is qualified, it is extracted and pumped into the finished product tank 8. The method in the whole device is reasonable, the structure is simple, the cost is low and the operation is convenient. The absorption tower 1 can reduce the pollution of acetaldehyde tail gas to the environment and improve the acetaldehyde absorption efficiency. A two-stage condensing device is adopted to condense the top steam step by step, improve the condensation efficiency, and reduce energy consumption. The two-stage reflux device is adopted to improve the acetaldehyde recovery rate, which can not only effectively improve the acetaldehyde recovery efficiency, reduce acetaldehyde waste, reduce steam consumption, and comprehensively utilize heat energy, but also reduce environmental pollution.

[0038] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0039] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An acetaldehyde distillation device, comprising an absorption tower (1), characterized in that: The absorption tower (1) is connected to a dilute acetaldehyde storage tank (2) through a pipeline, the dilute acetaldehyde storage tank (2) is connected to a primary condenser (4) through a pipeline, the primary condenser (4) is connected to a distillation tower (3) through a pipeline, the primary condenser (4) is also connected to a primary reflux tank (5) through a pipeline, the primary reflux tank (5) is connected to a secondary condenser (6) through a pipeline, the secondary condenser (6) is connected to a secondary reflux tank (7) through a pipeline, and both the primary reflux tank (5) and the secondary reflux tank (7) are connected to a finished product tank (8) through pipelines.

2. An acetaldehyde distillation device according to claim 1, characterized in that: The tail gas outlet of the dilute acetaldehyde storage tank (2) is connected to the inlet of the absorption tower (1) through a pipeline, and the acetaldehyde tail gas is circulated and absorbed again, wherein the absorption tower (1) adopts a rotary nozzle for spraying to completely absorb the acetaldehyde gas from all directions.

3. An acetaldehyde distillation device according to claim 1, characterized in that: The top steam of the distillation tower (3) enters the first-level reflux tank (5) after heat exchange through the first-level condenser (4). The first-level reflux tank (5) is connected to the second-level condenser (6). The acetaldehyde gas that is not completely liquefied is condensed by the second-level condenser (6) and stored in the second-level reflux tank (7).

4. An acetaldehyde distillation device according to claim 1, characterized in that: The first-stage condenser (4) is a spiral tube heat exchanger, and the second-stage condenser (6) is a cryogenic condensation heat exchanger, and the medium used is refrigerated brine.

5. An acetaldehyde distillation device according to claim 1, characterized in that: The first-level reflux tank (5) is the main reflux tank, and a liquid level meter is provided in the second-level reflux tank (7). When a certain amount of liquid is collected, the valve is opened and the liquid is pumped into the distillation tower (3) through the pipeline for reflux.

6. An acetaldehyde distillation device according to claim 1, characterized in that: Before entering the dilute acetaldehyde storage tank (2), the liquid first enters the primary condenser (4) to exchange heat with the top steam of the distillation tower (3) to increase its temperature, and then enters the distillation tower (3) for vaporization.

7. An acetaldehyde distillation device according to claim 1, characterized in that: A circulation pump (11) is provided on the side of the absorption tower (1), the water inlet of the circulation pump (11) is connected to the bottom end of the absorption tower (1) through a pipeline, and the water outlet of the circulation pump (11) is connected to a spray plate (12) through a pipeline. The spray plate (12) is located on the inner side of the absorption tower (1), and the spray plate (12) is located above the packing layer (15). The spray plate (12) is provided with uniformly distributed nozzles (13), and the nozzles (13) completely absorb acetaldehyde gas from all directions through rotary spraying.

8. An acetaldehyde distillation device according to claim 1, characterized in that: A rotating shaft (14) is provided on the spray plate (12), the rotating shaft (14) is mounted on the absorption tower (1) via a bearing, and the rotating shaft (14) is rotated by a motor, wherein the motor is mounted on the outer wall of the absorption tower (1).

Images