System for reducing by-products and improving acetone purity

Abstract

The utility model relates to the technical field of acetone purification, in particular to a system for reducing byproducts and improving acetone purity, which comprises a flash tank, the top of the flash tank is connected with an acetone tank through a pipeline, and the discharge end of the acetone tank is respectively connected with the flash tank, a decomposition reactor and an acetone rectifying tower through pipelines. The discharge end of the decomposition reactor is respectively connected with the flash tank and the rectification feed tank through pipelines, a tower top cooler is arranged between the flash tank and the acetone tank, and a tower top deep freezer is also arranged at the top of the acetone tank and is connected with a steam jet pump. According to the device disclosed by the utility model, materials in the flash tank are cooled in a manner that acetone flows back to the flash tank, so that the temperature in the flash tank is maintained in a reasonable interval, and the generation of tar byproducts is reduced; the steam jet pump can reduce the pressure intensity in the flash tank, so that the temperature of evaporating acetone in the flash tank is reduced, the generation of byproducts such as tar in the flash tank is reduced, and the purity of acetone is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of acetone purification, in particular to a system for reducing by-products and improving acetone purity. Background Art

[0002] When chemical companies produce phenol and acetone, they need to use flash tanks to distill the acetone from the product for purification. However, as the flash tank ages, its internal temperature tends to rise significantly. This temperature increase provides favorable conditions for a series of side reactions within the flash tank. Tar, a complex byproduct mixture produced by the flash tank temperature increase, is mainly composed of high-molecular-weight organic matter. Its formation and presence have an impact on the yield of the acetone product, mainly in the following two aspects:

[0003] 1. Affecting product quality: the high viscosity and low volatility of tar make it difficult to effectively separate it from acetone, thereby reducing the purity and quality of acetone and affecting the market value of the product;

[0004] 2. Increase the difficulty of subsequent processing. Tar may also adhere to the inner wall and pipeline of the equipment, resulting in decreased heat transfer efficiency, increased energy consumption, reduced acetone production load in the device, and may even cause equipment failure and safety hazards. Utility Model Content

[0005] In order to solve the deficiencies in the prior art, the utility model provides a system for reducing by-products and improving the purity of acetone.

[0006] To achieve the above objectives, the technical solution of the present invention is: a system for reducing by-products and improving the purity of acetone, comprising a flash tank, the top of which is connected to an acetone tank via a pipeline, a discharge end of the acetone tank being respectively connected to the flash tank, a decomposition reactor, and an acetone distillation tower via pipelines, a discharge end of the decomposition reactor being respectively connected to the flash tank and a distillation feed tank via pipelines, a tower top cooler being provided between the flash tank and the acetone tank, and a tower top cryocooler being further provided at the top of the acetone tank, the tower top cryocooler being connected to a steam jet pump.

[0007] Furthermore, an acetone discharge pump is provided on the main pipeline at the discharge end of the acetone tank.

[0008] Furthermore, a branch line connected to the distillation feed tank is provided on the connecting pipe between the acetone tank and the decomposition reactor.

[0009] Furthermore, a neutralization tank is provided between the decomposition reactor and the distillation feed tank.

[0010] Furthermore, an acetone temperature-raising heat exchanger is provided on the connecting pipe between the acetone tank and the acetone distillation tower.

[0011] Furthermore, two connecting pipes are provided between the acetone temperature-raising heat exchanger and the acetone distillation tower, and the two connecting pipes are respectively connected to the distillation section and the stripping section of the acetone distillation tower.

[0012] The beneficial effects achieved by the utility model are:

[0013] 1. The utility model cools the material in the flash tank by refluxing acetone to the flash tank, thereby maintaining the temperature in the flash tank within a reasonable range and reducing the generation of tar by-products; the steam jet pump can reduce the pressure in the flash tank, thereby reducing the temperature at which the acetone evaporates from the flash tank, reducing the generation of by-products such as tar in the flash tank, and improving the purity of the acetone.

[0014] 2. The utility model provides a branch line connected to a distillation feed tank on the connecting pipe between the acetone tank and the decomposition reactor. When the flash tank evaporates acetone too quickly and there is too much acetone in the acetone tank, the excess acetone will flow into the distillation feed tank through the pipe directly connecting the acetone tank and the distillation feed tank. The distillation feed tank buffers the excess acetone and reduces the acetone load of the entire device.

[0015] 3. Two connecting pipes are provided between the acetone distillation tower and the acetone heating heat exchanger of the utility model. The two connecting pipes are respectively connected to the distillation section and the stripping section of the acetone distillation tower. The staff can adjust the feed according to the quality of the acetone product so that the acetone flows into the appropriate stage of the acetone distillation tower, thereby improving the purity of the final acetone. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0017] Explanation of the markings in the figure: 1. Flash tank; 2. Tower top cooler; 3. Acetone tank; 4. Tower top deep freezer; 5. Steam jet pump; 6. Acetone discharge pump; 7. Acetone heating heat exchanger; 8. Acetone distillation tower; 9. Decomposition reactor; 10. Distillation feed tank; 11. Neutralization tank. DETAILED DESCRIPTION

[0018] In order to better understand the purpose, structure and function of the present invention, the following is a further detailed description of a system for reducing by-products and improving acetone purity of the present invention in conjunction with the accompanying drawings.

[0019] like Figure 1As shown, a system for reducing by-products and improving acetone purity includes a flash tank 1 containing a mixture of phenol, acetone, etc. The top of the flash tank 1 is connected to an acetone tank 3 via a connecting pipe. A tower top cooler 2 is provided between the acetone tank 3 and the flash tank 1. A tower top cryocooler 4 is also provided on the top of the acetone tank 3. The tower top cryocooler 4 is connected to a steam jet pump 5 via a connecting pipe. When the steam jet pump 5 is started, the steam jet pump 5 can reduce the pressure in the acetone tank 3 and the flash tank 1, thereby reducing the temperature at which the acetone in the flash tank 1 evaporates. Under the condition of a lower evaporation temperature, the generation of by-products such as tar in the flash tank 1 can be reduced.

[0020] An acetone discharge pump 6 is provided on the main pipeline at the discharge end of the acetone tank 3. The discharge end of the acetone tank 3 is respectively connected to the flash tank 1, the decomposition reactor 9 and the acetone distillation tower 8 through connecting pipes. The acetone in the acetone tank 3 is transported to different devices according to different working conditions. The decomposition reactor 9 is respectively connected to the flash tank 1 and the distillation feed tank 10 through connecting pipes. A neutralization tank 11 is provided between the decomposition reactor 9 and the distillation feed tank 10. The neutralization tank 11 is filled with water-oil two-phase substances. The oil phase is a mixture of phenol and acetone and some heavy component impurities, and the water phase is an acidic sodium sulfate solution. The connecting pipe between the acetone tank 3 and the decomposition reactor 9 A branch pipe is provided directly connected to the distillation feed tank 10. The connecting pipe between the acetone tank 3 and the acetone distillation tower 8 is equipped with an acetone heating heat exchanger 7. The acetone heating heat exchanger 7 heats the medium, raising the temperature of the acetone in the acetone heating heat exchanger 7 to 50°C before entering the acetone distillation tower 8. Two connecting pipes are provided between the acetone distillation tower 8 and the acetone heating heat exchanger 7. The two connecting pipes are respectively connected to the distillation section and stripping section of the acetone distillation tower 8. The staff can adjust the feed according to the quality of the acetone product to ensure that the acetone flows into the appropriate stage of the acetone distillation tower 8, thereby improving the purity of the final acetone. Valves are installed on each connecting pipe in this system. The opening and closing of the valves and the size of the opening and closing control the flow direction and flow rate of the material in the system.

[0021] When the utility model is working, the acetone in the decomposed feed in the flash tank 1 is evaporated into the acetone tank 3, the tower top cooler 2 at the top of the acetone tank 3 converts the gas phase acetone back into the liquid phase and enters the acetone tank 3, and the steam jet pump 5 discharges the gas in the acetone tank 3 and the flash tank 1, thereby reducing the pressure in the flash tank 1, thereby reducing the temperature at which the acetone in the flash tank 1 is evaporated, reducing the generation of by-products such as tar in the flash tank 1, and improving the purity of the acetone.

[0022] The acetone in acetone tank 3 is delivered to different devices via acetone discharge pump 6 depending on the operating conditions. Under normal operating conditions, the acetone is divided into three parts. The first part is returned to flash tank 1 as reflux to cool it; the second part is sent to decomposition reactor 9 for recycling; and the third part is sent to acetone rectification tower 8 for further purification to produce a high-quality product. If the acetone is distilled out of flash tank 1 too quickly, there will be too much acetone in acetone tank 3. This excess acetone will flow into rectification feed tank 10 through the pipeline directly connecting the acetone tank 3 and the rectification feed tank 10. Rectification feed tank 10 buffers the excess acetone, reducing the acetone load of the entire device.

[0023] Of the three acetone flow paths, acetone preferentially flows into acetone distillation column 8. Acetone heating heat exchanger 7 heats the acetone entering acetone distillation column 8 to approximately 50°C, bringing the temperature of the acetone into the feed inlet of acetone distillation column 8 to approximately the same level. This facilitates the removal of impurities from the acetone product while maintaining the overall operation of acetone distillation column 8 and resulting in a superior acetone product. The remaining acetone preferentially returns to flash tank 1, maintaining the temperature therein at no more than 78°C. This lowers the temperature, helps reduce the formation of byproducts such as tar, and improves acetone yield. Finally, the remaining acetone is transported to decomposition reactor 9 for thermal decomposition. The decomposed acetone refluxes back into flash tank 1, participating in the acetone cycle. Excess acetone passes through neutralization tank 11 and enters distillation feed tank 10.

[0024] It is understood that the present invention is described by way of certain embodiments, and those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. Furthermore, under the guidance of the present invention, these features and embodiments may be modified to suit specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. A system for reducing by-products and improving acetone purity, characterized by: The invention comprises a flash tank (1), wherein the top of the flash tank (1) is connected to an acetone tank (3) via a pipeline, the discharge end of the acetone tank (3) is respectively connected to the flash tank (1), a decomposition reactor (9) and an acetone distillation tower (8) via pipelines, the discharge end of the decomposition reactor (9) is respectively connected to the flash tank (1) and a distillation feed tank (10) via pipelines, a tower top cooler (2) is provided between the flash tank (1) and the acetone tank (3), and a tower top deep cooler (4) is further provided at the top of the acetone tank (3), and the tower top deep cooler (4) is connected to a steam jet pump (5).

2. The system for reducing by-products and improving acetone purity according to claim 1, characterized in that: An acetone discharge pump (6) is provided on the main pipeline at the discharge end of the acetone tank (3).

3. The system for reducing by-products and improving acetone purity according to claim 1, characterized in that: A branch line connected to the distillation feed tank (10) is provided on the connecting pipe between the acetone tank (3) and the decomposition reactor (9).

4. The system for reducing by-products and improving acetone purity according to claim 1, characterized in that: A neutralization tank (11) is provided between the decomposition reactor (9) and the rectification feed tank (10).

5. The system for reducing by-products and improving acetone purity according to claim 1, characterized in that: An acetone temperature-raising heat exchanger (7) is provided on the connecting pipe between the acetone tank (3) and the acetone distillation tower (8).

6. The system for reducing by-products and improving acetone purity according to claim 5, characterized in that: Two connecting pipes are provided between the acetone temperature-raising heat exchanger (7) and the acetone distillation tower (8), and the two connecting pipes are respectively connected to the distillation section and the stripping section of the acetone distillation tower (8).

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