Ethylene oxide dealdehyding refining system

Abstract

The utility model discloses an ethylene oxide dealdehyding and refining system, which relates to the technical field of ethylene oxide dealdehyding and refining, and comprises a rectifying tower and 71 layers of tower trays arranged in the rectifying tower, an acetaldehyde discharge outlet is arranged on the outer side of a tower body between the 21st layer of tower tray to the 61st layer of tower tray in the rectifying tower, an acetaldehyde discharge pipe is arranged on the acetaldehyde discharge outlet, and an acetaldehyde discharge pipe is arranged on the acetaldehyde discharge pipe. The top of the rectifying tower is connected with a heat exchanger through a pipeline, and the heat exchanger is connected with a return tank through a pipeline. Through the desalted water pipe, the acetaldehyde discharge pipe, the reflux tank, the nitrogen pipe and the formaldehyde discharge pipe, the desalted water pipe is used for washing aldehydes on the inner side of the rectifying tower by using desalted water, the acetaldehyde discharge pipe can be used for discharging acetaldehyde so as to reduce acetaldehyde aggregation in the tower, a gas phase at the top of the tower is condensed by the heat exchanger, and non-condensable gas is discharged to a rear system. A small amount of condensate is discharged and returns to the feed after light hydrocarbon removal, so that the content of aldehyde in ethylene oxide is reduced, and the production requirements are met.

Description

Technical Field

[0001] The utility model relates to the technical field of ethylene oxide dealdehyde refining, in particular to an ethylene oxide dealdehyde refining system. Background Technique

[0002] Ethylene oxide is an organic compound with the chemical formula C2H4O. It is a toxic carcinogen and was previously used to make fungicides. Ethylene oxide is flammable and explosive and not easy to transport over long distances, so it has strong regionality. It is widely used in industries such as washing, pharmaceuticals, and printing and dyeing. In the chemical-related industries, it can be used as the starting agent for detergents. During the manufacturing process of ethylene oxide, formaldehyde and acetaldehyde will be produced, so a refining system is needed to carry out rectification and purification treatment on ethylene oxide.

[0003] During the high-load operation of the existing ethylene oxide refining tower, the aldehyde content in the ethylene oxide product continuously rises. Especially at the end of the catalyst use period, the reaction temperature gradually increases, resulting in more side reactions and an increase in the amount of aldehydes generated by the reaction, which will further lead to an increase in the aldehyde content in the feed of the ethylene oxide refining tower. Aldehydes have an inhibitory effect on the downstream polyether reaction and will also darken the color of the polyether. Therefore, a new type of refining system is needed to solve the existing problems. Summary of the Invention

[0004] The technical problem to be solved by the utility model is to overcome the existing defects and provide an ethylene oxide dealdehyde refining system. By setting a desalting water pipe, an acetaldehyde discharge pipe, a reflux tank, a nitrogen gas pipe, and a formaldehyde discharge pipe, the aldehyde content in ethylene oxide is reduced to meet the production requirements, and the problems in the background technique can be effectively solved.

[0005] To achieve the above purpose, the utility model provides the following technical scheme: an ethylene oxide dealdehyde refining system, including a rectification tower and 71 trays installed in the rectification tower. An acetaldehyde discharge outlet is arranged on the outer side of the tower body between the 21st and 61st trays in the rectification tower. An acetaldehyde discharge pipe is installed on the acetaldehyde discharge outlet. The top of the rectification tower is connected to a heat exchanger through a pipeline. The heat exchanger is connected to a reflux tank through a pipeline. The gas outlet end of the reflux tank is connected to a nitrogen gas pipe. The reflux tank is connected to the position of the 71st tray in the rectification tower through a reflux pump and a pipeline. An outlet pipe is installed on the outer side of the tower body at the position of the 61st tray. A reflux pump is installed on the reflux pipeline between the reflux tank and the rectification tower. A desalting water pipe is installed on the outer side of the tower body at the position of the 21st tray in the rectification tower. A formaldehyde discharge pipe is installed on the gas outlet pipeline of the reflux tank.

[0006] Further, feed pipes are installed on the outer side of the tower body at the positions of the 1st, 2nd, and 3rd trays of the rectification tower.

[0007] Further, a bottom reboiler of the distillation column is installed on the lower side of the feed pipe, and a steam pipe is installed inside the distillation column where the bottom reboiler extends.

[0008] Further, the tray is connected to the inside of the distillation column by bolts. A heat exchanger and a reflux pump are installed on the pipeline of the discharge pipe, and the discharge port of the reflux pump on the discharge pipe is connected to the upper part of the discharge pipe through a pipeline.

[0009] Further, a pipeline on the reflux pipeline of the reflux tank flows into the reflux tank through a pipeline, and there are two heat exchangers on the gas outlet pipeline at the top of the distillation column.

[0010] Further, the bottom of the distillation column and a reflux pump form a reflux pipeline through a pipeline.

[0011] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0012] Through the desalination water pipe, acetaldehyde discharge pipe, reflux tank, nitrogen pipe and formaldehyde discharge pipe provided by the utility model, the desalination water pipe flushes aldehydes inside the distillation column with desalinated water, and the acetaldehyde discharge pipe can lead out acetaldehyde for discharge to reduce the accumulation of acetaldehyde in the tower. After the gas phase at the top of the tower is condensed by the heat exchanger, the non-condensable gas is discharged to the subsequent system, and a small amount of the condensed liquid returns to the feed after light hydrocarbon removal, so that the aldehyde content in ethylene oxide is reduced to meet the production requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic structural diagram of the production process of the present utility model;

[0014] Figure 2 is a schematic main sectional view structure diagram of the distillation column in the present utility model.

[0015] In the figure: 1. Desalination water pipe; 2. Feed pipe; 3. Bottom reboiler; 4. Acetaldehyde discharge pipe; 5. Discharge pipe; 6. Formaldehyde discharge pipe; 7. Distillation column; 8. Nitrogen pipe; 9. Heat exchanger; 10. Reflux tank; 11. Steam pipe; 12. Tray. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0017] Please refer to Figure 1-2, this embodiment provides a technical solution: an ethylene oxide dealdehyde refining system, including a distillation column 7 and 71 trays 12 installed in the distillation column 7. An acetaldehyde discharge outlet is provided on the outer side of the column body between the 21st and 61st trays 12 in the distillation column 7. A acetaldehyde discharge pipe 4 is installed on the acetaldehyde discharge outlet. The top of the distillation column 7 is connected to a heat exchanger 9 through a pipeline. The heat exchanger 9 is connected to a reflux drum 10 through a pipeline. The gas outlet end of the reflux drum 10 is connected to a nitrogen pipe 8. The reflux drum 10 is connected to the position of the 71st tray 12 in the distillation column 7 through a reflux pump and a pipeline. A discharge pipe 5 is installed on the outer side of the column body at the position of the 61st tray 12. A reflux pump is installed on the reflux pipeline between the reflux drum 10 and the distillation column 7. A formaldehyde discharge pipe 6 is installed on the gas outlet pipeline of the reflux drum 10. A desalinated water pipe 1 is installed on the outer side of the column body at the position of the 21st tray 12 in the distillation column 7.

[0018] Feeding pipes 2 are installed on the outer side of the column body at the positions of the 1st, 2nd and 3rd trays 12 in the distillation column 7.

[0019] A bottom reboiler 3 is installed below the feeding pipe 2. The bottom reboiler 3 extends into the distillation column 7 and a steam pipe 11 is installed inside.

[0020] The trays 12 are connected to the inside of the distillation column 7 by bolts. A heat exchanger 9 and a reflux pump are installed on the pipeline of the discharge pipe 5. The discharge outlet of the reflux pump on the discharge pipe 5 is connected to the upper part of the discharge pipe 5 through a pipeline.

[0021] The reflux pipeline on the reflux drum 10 flows into the reflux drum 10 through a pipeline. There are two heat exchangers 9 on the gas outlet pipeline at the top of the distillation column 7.

[0022] The bottom of the distillation column 7 forms a reflux pipeline through a pipeline and a reflux pump.

[0023] The working principle of the ethylene oxide dealdehyde refining system provided by the present utility model is as follows: As Figure 1 - Figure 2 shown, during use, the feeding pipe 2 feeds through the first tray 12, the second tray 12, and the fourth tray 12. The feeding position can also be adjusted according to production needs. The bottom reboiler 3 heats. At the position of the 21st tray 12, the desalinated water conveyed through the desalinated water pipe 1 flushes the aldehydes in the refined ethylene oxide with desalinated water. The acetaldehyde concentration section between the 21st and 61st trays is led out and discharged through the acetaldehyde discharge pipe 4 to reduce the accumulation of acetaldehyde in the column. The dealdehyde ethylene oxide is discharged through the discharge pipe 5 outside the 61st tray 12. The gas phase at the top of the column is condensed by the heat exchanger 9, and the non-condensable gas is discharged to the subsequent system. The condensate flows back to the 71st tray 12 through the reflux drum 10. Sampling points are added to the column body to analyze the components of the trays 12 to facilitate the adjustment of the acetaldehyde discharge amount.

[0024] The above are only embodiments of the present utility model, and thus do not limit the patent scope of the present utility model. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of the present utility model, or directly or indirectly applied in other related technical fields, shall similarly be included within the patent protection scope of the present utility model.

Claims

1. An ethylene oxide dealdehyde refining system, comprising a distillation tower (7) and 71 layers of trays (12) installed in the distillation tower (7), characterized in that: An acetaldehyde discharge outlet is arranged on the outer side of the tower body between the 21st and 61st tower trays (12) in the distillation tower (7), and an acetaldehyde discharge pipe (4) is installed on the acetaldehyde discharge outlet. A heat exchanger (9) is connected to the top of the distillation tower (7) via a pipeline, and the heat exchanger (9) is connected to a reflux tank (10) via a pipeline. A nitrogen pipe (8) is connected to the gas outlet end of the reflux tank (10). The reflux tank (10) is connected to the position of the 71st tower tray (12) in the distillation tower (7) via a reflux pump and a pipeline. A discharge pipe (5) is installed on the outer side of the tower body at the position of the 61st tower tray (12). A reflux pump is installed on the reflux pipeline between the reflux tank (10) and the distillation tower (7). A formaldehyde discharge pipe (6) is installed on the gas outlet pipeline of the reflux tank (10). A desalted water pipe (1) is installed on the outer side of the tower body at the position of the 21st tower tray (12) of the distillation tower (7).

2. The ethylene oxide dealdehyde refining system according to claim 1, characterized in that: Feed pipes (2) are installed on the outside of the tower body at the positions of the first, second and third tower trays (12) of the distillation tower (7).

3. The ethylene oxide dealdehyde refining system according to claim 2, characterized in that: A tower bottom reboiler (3) is installed at the lower side of the feed pipe (2), and a steam pipe (11) is installed on the inner side of the tower bottom reboiler (3) extending into the distillation tower (7).

4. The ethylene oxide dealdehyde refining system according to claim 1, characterized in that: The tower plate (12) is connected to the inner side of the distillation tower (7) by bolts, a heat exchanger (9) and a reflux pump are installed on the discharge pipe (5), and the discharge port of the reflux pump on the discharge pipe (5) is connected to the upper part of the discharge pipe (5) by a pipeline.

5. The ethylene oxide dealdehyde refining system according to claim 1, characterized in that: The reflux pipeline on the reflux tank (10) flows into the reflux tank (10) through a pipeline, and there are two heat exchangers (9) on the gas outlet pipeline at the top of the distillation tower (7).

6. The ethylene oxide dealdehyde refining system according to claim 3, characterized in that: The bottom of the distillation tower (7) is provided with a reflux pipeline through a pipeline and a reflux pump.

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