A system for removing light components in the production of epichlorohydrin

Abstract

The utility model discloses an epoxy chloropropane production light component removal's system, including the primary distillation tower, the primary distillation liquid tank and the cyclization tower, the primary distillation tower top is connected with the primary distillation tower feed pipe, gas phase pipe II and oil phase reflux pipe, its bottom is connected with the tower bottom material discharge pipe of the removal rectifying tower, the primary distillation liquid tank, top is equipped with with the gas inlet I of gas phase pipe II of the primary distillation tower's interface, its lower part is equipped with with the oil phase reflux pipe of the primary distillation tower's interface oil phase reflux mouth, its lower part still is equipped with with the light component recovery pipe of the cyclization tower's intercommunication, the cyclization tower upper portion is connected with dichloropropanol feeding pipe, liquid alkali feeding pipe, gas phase pipe I, water phase reflux pipe, its upper portion still is equipped with with a plurality of with the liquid inlet of light component recovery pipe's connection, and the liquid inlet is established at the different height place of cyclization tower, installs the valve at every liquid inlet, its bottom is connected with the tower bottom waste water pipe. Compared with the production device that does not remove light component, the system has realized material reuse, reduced raw material waste, improved product yield and purity.

Description

Technical Field

[0001] This utility model relates to the field of epichlorohydrin preparation technology, specifically a system for removing light components in epichlorohydrin production. Background Technology

[0002] Epichlorohydrin is an important organic chemical raw material and fine chemical product. It is mainly used to produce epoxy resins. In addition, it can also be used to produce nitroglycerin explosives, chlorohydrin rubber, glycidyl ether, surfactants, paper wet strength enhancers (amide epichlorohydrin resin), water treatment agents, flame retardants, quaternary ammonium salts, ion exchange resins, plasticizers and many other products. It also has a certain consumption in the fields of pharmaceuticals, pesticides, solvents and specialty adhesives.

[0003] The glycerol method for preparing epichlorohydrin uses dichloropropanol, produced by the reaction of glycerol and hydrogen chloride, as a raw material. This dichloropropanol then undergoes a cyclization reaction with sodium hydroxide or calcium oxide to ultimately produce epichlorohydrin. During the entire reaction process, a certain amount of light components are produced as byproducts. These light components can affect the color and purity of the product, resulting in substandard product color.

[0004] To separate the light components from the product, the original process used a primary distillation column. However, the light components contained some of the finished product, leading to product loss. To improve product yield and reduce loss, the original process returned the light components to the cyclization column separator. However, this operation prevented the light components from being completely separated from the system, and some of them continued to circulate in the reaction system. When the amount of light components exceeded a certain level, the process had to be stopped for cleaning. Utility Model Content

[0005] The technical problem this invention aims to solve is to address the shortcomings of existing technologies by providing a system for removing light components generated during the production of epichlorohydrin via the glycerol method. This system reduces raw material waste and improves product yield and purity.

[0006] The technical problem to be solved by this utility model is achieved through the following technical solution: a system for removing light components in the production of epichlorohydrin, characterized in that it includes a primary distillation tower, a primary distillation separator, and a cyclization tower. The primary distillation column is connected to the primary distillation column feed pipe, vapor phase pipe II and oil phase reflux pipe I at the top, and to the bottom of the distillation column discharge pipe at the bottom. The primary distillation separator is used to achieve automatic stratification and preliminary separation of oil and water. Its top is equipped with an air inlet I connected to the vapor phase pipe II of the primary distillation column, and its lower part is equipped with an oil phase reflux port connected to the oil phase reflux pipe of the primary distillation column. Its lower part is also equipped with a light component recovery pipe connected to the circulator column. The light component recovery pipe is equipped with a liquid power control element, which can be a hydraulic pump, oil pump or other power device. The cyclone tower is used to remove light components. Its upper part is connected to a dichloropropanol feed pipe, a liquid alkali feed pipe, a gas phase pipe I, and a water phase reflux pipe. The upper part is also equipped with several liquid inlets connected to the light component recovery pipe. The liquid inlets are located at different heights of the cyclone tower. Each liquid inlet is equipped with a liquid flow control element. Its bottom is connected to a wastewater pipe at the bottom of the tower. The liquid flow control element can be a pressure valve, a flow valve, or a directional valve.

[0007] The technical problem to be solved by this utility model can also be achieved through the following technical solution: the system for removing light components in epichlorohydrin production described above, the system further includes a cyclization separator and a crude product buffer tank. The circulating separator has an air inlet II at the top that is connected to the gas phase pipe I of the circulating tower, a water phase reflux port at the bottom that is connected to the water phase reflux pipe, and an oil phase transfer pipe at the bottom that is connected to the crude product buffer tank. The crude product buffer tank is connected at the top to the oil phase transfer pipe of the cyclic separator and at the bottom to the feed pipe of the primary distillation column.

[0008] The technical problem to be solved by this utility model can also be achieved through the following technical solution: the system for removing light components in the production of epichlorohydrin described above, wherein the cyclization separator and the initial distillation separator are oil-water separators.

[0009] The technical problem to be solved by this utility model can also be achieved through the following technical solution: In the above-described system for removing light components in epichlorohydrin production, the cyclone tower is provided with multiple layers of baffles fixedly arranged inside, with adjacent baffles staggered vertically to extend the liquid travel and improve processing efficiency.

[0010] The technical problem to be solved by this utility model can also be achieved through the following technical solution: In the above-mentioned system for removing light components in the production of epichlorohydrin, a self-cleaning filter is installed on the wastewater pipe at the bottom of the cyclization tower to prevent polymer from clogging the cyclization equipment and ensure continuous production.

[0011] Compared with the prior art, the beneficial technical effects of this utility model are: First, by setting up a primary distillation tank, preliminary separation is achieved through automatic oil-water stratification. The oil phase is returned to the primary distillation tower, while the aqueous phase (containing more light components) is transferred into the circulator tower through pipelines. Second, by setting up a cyclization tower, the glycerol carried in the raw material and the glycerol produced by the reverse reaction in the cyclization tower are used for preliminary reaction. The reaction products are polymerized under the action of alkali, thereby achieving the removal of light components.

[0012] Third, by setting inlet ports at different heights in the cyclization tower, and combining them with pumps and valves, the different locations for adding the alkali can be determined according to the different alkali concentrations at different locations in the cyclization tower. This can reduce the hydrolysis of epichlorohydrin and thus increase the yield of epichlorohydrin. Fourth, by installing a bottom wastewater pipe at the bottom of the cyclone tower, the acrolein polymer is discharged from the bottom wastewater pipe through the aqueous phase, eliminating the need to stop the machine to remove light components and improving the recovery rate of epichlorohydrin.

[0013] Compared to production devices that do not remove light components, the system described in this invention enables material reuse, reduces raw material waste, and improves product yield and purity. Compared to light component separation devices used in the market, it replaces diethanolamine or diethylamine in polymerization with glycerol and liquid alkali, avoiding the introduction of new components into the reaction system and reducing the types of impurities. This invention modifies the light component return pipeline, achieving complete removal of acrolein from the light components while minimizing epichlorohydrin loss. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the process flow of this utility model.

[0015] Figure label: 1. Circulation tower; 2. Dichloropropanol feed pipe; 3. Liquid alkali feed pipe; 4. Aqueous phase reflux pipe; 5. Bottom wastewater pipe; 6. Multi-layer baffle plate; 7. Circulation separator; 8. Gas phase pipe I; 9. Oil phase transfer pipe; 10. Crude product buffer tank; 11. Primary distillation tower; 12. Primary distillation tower feed pipe; 13. Oil phase reflux pipe; 14. Bottom product discharge pipe; 15. Primary distillation separator; 16. Gas phase pipe II; 17. Light component recovery pipe; 18. Liquid inlet. Detailed Implementation

[0016] The specific technical solutions of this utility model are further described below with reference to the accompanying drawings, so as to enable those skilled in the art to further understand this utility model, without constituting a limitation on its rights.

[0017] Reference Figure 1 A system for removing light components in epichlorohydrin production includes a primary distillation column 11, a primary distillation separator 15, a cyclization column 1, a cyclization separator 7, and a crude product buffer tank 10. The primary distillation column 11 is connected to the primary distillation column feed pipe 12, the gas phase pipe II 16 and the oil phase reflux pipe 13 at its top, and to the bottom of the column, the bottom material discharge pipe 14, which leads to the rectification column, at its bottom. The primary distillation separator 15 is used to achieve automatic stratification and preliminary separation of oil and water. Its top is provided with an air inlet I connected to the gas phase pipe II 16 of the primary distillation column 11, and its lower part is provided with an oil phase reflux port connected to the oil phase reflux pipe 13 of the primary distillation column 11. Its lower part is also provided with a light component recovery pipe 17 connected to the circulator column 1. A pump body is installed on the light component recovery pipe 17. The cyclone tower 1 is used to remove light components. Its upper part is connected to a dichloropropanol feed pipe 1, a liquid alkali feed pipe 2, a gas phase pipe I 8, and an aqueous phase reflux pipe 4. Its upper part is also equipped with several liquid inlets 18 connected to the light component recovery pipe 17. The liquid inlets 18 are located at different heights of the cyclone tower 1. Each liquid inlet 18 is equipped with a valve, and its bottom is connected to the bottom wastewater pipe 5. The circulating separator 7 has an air inlet II at its upper part that is connected to the gas phase pipe I 8 of the circulating tower, and a water phase reflux port at its lower part that is connected to the water phase reflux pipe 4. It also has an oil phase transfer pipe 9 at its bottom that is connected to the crude product buffer tank 10. The oil phase transfer pipe 9 is connected to the top of the circulating separator 7. The crude product buffer tank 10 is connected at its top to the light component recovery pipe 4 of the cyclic separator 7, and at its bottom to the primary distillation column feed pipe 12 of the primary distillation column 11.

[0018] The circulatory tower 1 is equipped with multiple layers of baffles 6 fixedly arranged inside. The multiple layers of baffles 6 are composed of horizontal plate-shaped structures arranged alternately on the top and bottom and left and right. The wastewater pipe 5 at the bottom of the circulatory tower 1 is equipped with a self-cleaning filter. The self-cleaning filter is existing technology. Other types of filters can also be selected according to the usage requirements. The circulating separator 7 has its inlet end connected to the liquid phase reflux pipe 4 of the circulating tower 1. It also has a gas phase pipe 8 at the top and an oil phase transfer pipe 9 at the bottom. The gas phase pipe 8 is connected to the top of the circulating separator 7. The circulating separator 7 is an oil-water separator. Pumps (not shown) and valves (not shown) can be installed on the gas phase pipe 8 and the oil phase transfer pipe 9. These can be selected according to the usage requirements. The processing technology of the system for removing light components in the production of epichlorohydrin described in this utility model is as follows: Dichloropropanol enters the system through the dichloropropanol feed pipe 2 at the top of the cyclization tower 1, while liquid alkali is added to the cyclization tower 1 through the liquid alkali feed pipe 3. Inside the cyclization tower 1, dichloropropanol and alkali solution undergo a cyclization reaction to generate epichlorohydrin. During this process, a reaction mixture containing light components is generated. The vapor after the reaction enters the cyclization separator 7 from the vapor phase pipe I8 of the cyclization tower 1 to achieve condensation and preliminary oil-water separation. In the cyclization separator 7, the material is divided into an oil phase and a water phase. The water phase is returned to the cyclization tower for recycling through the water phase reflux pipe 4, while the oil phase enters the crude product buffer tank 10 for temporary storage through the oil phase transfer pipe 9. The oil phase in the crude product buffer tank 10 enters the primary distillation column 11 through the feed pipe 12 for rectification separation. In the primary distillation column 11, the light components distill out from the top of the column and enter the primary distillation separator 15 through the vapor phase pipe II 16, while the main product epichlorohydrin is sent from the bottom of the column to the subsequent rectification process through the bottom feed pipe 14. The primary distillation separator 15 further separates the light components into oil and water phases. The oil phase is returned to the top of the primary distillation column 11 for recycling through the oil phase reflux pipe 13, while the water phase is sent back to the top of the cyclization column 1 for reprocessing through the light component recovery pipe 17. The liquid alkali feed pipe installed on the light component recovery pipe 17 can replenish alkali as needed to ensure that the reaction system maintains a sufficient alkali concentration. The entire system extends the reaction time through multi-layer baffles 6, promoting the full polymerization of light components. The self-cleaning filter at the bottom of the cyclization tower 1 can effectively intercept polymer residues and prevent equipment blockage. Through material recycling and optimized separation process, the system achieves efficient removal of light components in the epichlorohydrin production process, significantly improving product purity and yield, while avoiding impurity problems caused by the introduction of external reagents.

Claims

1. A system for removing light components in epichlorohydrin production, characterized in that: The system includes a primary distillation column, a primary distillation separator, and a cyclic distillation column; The primary distillation column is connected to the primary distillation column feed pipe, vapor phase pipe II and oil phase reflux pipe at its top, and to the bottom material discharge pipe for the rectification column at its bottom. The primary distillation separator is used to achieve automatic stratification and preliminary separation of oil and water. Its top is equipped with an air inlet I connected to the gas phase pipe II of the primary distillation column, and its lower part is equipped with an oil phase reflux port connected to the oil phase reflux pipe of the primary distillation column. Its lower part is also equipped with a light component recovery pipe connected to the circulator column. The light component recovery pipe is equipped with a liquid dynamic control element. The cyclone tower is used to remove light components. Its upper part is connected to a dichloropropanol feed pipe, a liquid alkali feed pipe, a gas phase pipe I, and a water phase reflux pipe. Its upper part is also equipped with several liquid inlets connected to the light component recovery pipe. The liquid inlets are located at different heights of the cyclone tower. Each liquid inlet is equipped with a liquid flow control element. Its bottom is connected to the bottom wastewater pipe.

2. The system for removing light components in epichlorohydrin production according to claim 1, characterized in that: The system also includes a cyclization separator and a crude product buffer tank. The circulating separator has an air inlet II at the top that is connected to the gas phase pipe I of the circulating tower, a water phase reflux port at the bottom that is connected to the water phase reflux pipe, and an oil phase transfer pipe at the bottom that is connected to the crude product buffer tank. The crude product buffer tank is connected at the top to the oil phase transfer pipe of the cyclic separator and at the bottom to the feed pipe of the primary distillation column.

3. The system for removing light components in epichlorohydrin production according to claim 2, characterized in that: The aforementioned cyclic separator and primary distillation separator are oil-water separators.

4. The system for removing light components in epichlorohydrin production according to claim 1, characterized in that: The circulator tower is equipped with multiple layers of baffles fixed inside, with adjacent baffles staggered vertically.

5. A system for removing light components in epichlorohydrin production according to claim 1, characterized in that: A self-cleaning filter is installed on the wastewater pipe at the bottom of the circulatory tower.

Images