High purity alkyl tertiary amine crude product rectification system

Abstract

The utility model relates to the field of chemical production provides a kind of high purity alkyl tertiary amine crude product rectification system. Including membrane evaporation unit, rectifying column and cooler unit, membrane evaporation unit includes feed pump, heat exchanger, membrane evaporator and transfer tank, the vapor outlet of the top of rectifying column is connected the heat exchange passage of heat exchanger, and is connected cooler unit by heat exchange passage, cooler unit includes condenser and cooler, and cooler is connected with front distillation tank and finished product tank by pipeline and valve, by using membrane evaporator to heat crude product, improve the efficiency of evaporation, circulation can be formed between membrane evaporator and transfer tank, and finished product in crude product can be completely evaporated and sent into rectifying column, improve finished product yield, avoid waste. By heat exchanger, crude product is preheated using the steam in rectifying column, can save the energy consumption of evaporation end, simultaneously relieve the condensing pressure of condensing section, reduce the dosage of condensate.

Description

Technical Field

[0001] This utility model relates to the field of chemical production, specifically to a high-purity alkyl tertiary amine crude distillation system. Background Technology

[0002] Alkyl tertiary amine products are generally produced by reacting alcohols and dimethylamines in a reactor with the addition of a catalyst and under certain temperature and pressure settings. By controlling the process conditions, the content of the finished product in the crude product obtained in the reactor can reach about 92%. In addition to the finished product, the crude product in the reactor also contains unreacted raw material alcohols and substances with relatively high boiling points such as primary amines and secondary amines produced by side reactions.

[0003] Alkyl tertiary amines are commonly used in cosmetics, detergents, and other fields. During use, their purity needs to reach over 99%, so further distillation of the crude product is necessary to improve its purity. Conventional distillation typically uses a distillation column with condensation, but this method is inefficient and the final product does not meet the high-purity requirements. Summary of the Invention

[0004] To improve the purity of alkyl tertiary amine products, this invention provides a high-purity alkyl tertiary amine crude distillation system.

[0005] The technical solution adopted by this utility model is as follows: A high-purity alkyl tertiary amine crude product distillation system includes a thin-film evaporation unit, a distillation column, and a cooler unit. The thin-film evaporation unit includes a feed pump, a heat exchanger, a thin-film evaporator, and a transfer tank. The crude product is fed into the heat exchanger from the feed pump via a pipeline. After heat exchange in the heat exchanger, the crude product enters the thin-film evaporator for evaporation. The gas outlet of the thin-film evaporator is connected to the gas inlet of the distillation column. The bottom of the thin-film evaporator and the bottom of the distillation column are connected to the transfer tank via pipelines and valves. The vapor outlet at the top of the distillation column is connected to the heat exchange channel of the heat exchanger and then to the cooler unit. The cooler unit includes a condenser and a cooler. The condenser is connected to the heat exchange channel of the heat exchanger. The bottom of the condenser is connected to the reflux port of the distillation column and the cooler via a three-way control valve and a pipeline, respectively. The cooler is connected to a fore-distillation tank and a finished product tank via pipelines and valves. The bottom of the fore-distillation tank is connected to the transfer tank via a pipeline.

[0006] Furthermore, the cooler unit includes two condensers connected in series, and circulating cooling water flows through the condensers.

[0007] Furthermore, the vapor in the heat exchanger enters the first-stage condenser, and the liquefied product in the heat exchanger enters the reflux port of the distillation column or the cooler through the pipeline and the three-way control valve.

[0008] Furthermore, a circulation pump is installed on the outside of the transfer tank, which draws high-boiling-point substances from the transfer tank and circulates them into the thin-film evaporator.

[0009] Furthermore, the transfer tank is provided with a jacket on its outer side, and circulating hot water flows through the jacket.

[0010] Furthermore, it includes one or two thin-film evaporators connected in series, wherein the heat exchange medium of the thin-film evaporator is heat transfer oil.

[0011] Furthermore, the foredistillation tank, the finished product tank, and the second-stage condenser are each connected to a negative pressure pipeline.

[0012] Furthermore, the foredistillation tank is located above the transfer tank.

[0013] Furthermore, the cooler's output port is equipped with an online sampling port.

[0014] After adopting the above technical solution, the beneficial effects of this utility model are as follows: By using a thin-film evaporator to heat the crude product, the evaporation efficiency is improved. A circulation system can be formed between the thin-film evaporator and the transfer tank, ensuring that the finished product from the crude product is completely evaporated and sent into the distillation column, thereby increasing the product yield and avoiding waste. Preheating the crude product with steam from the distillation column via a heat exchanger saves energy consumption at the evaporation end, while also relieving condensation pressure in the condensation section and reducing condensate consumption.

[0015] In the initial stage of the reaction, before reaching equilibrium, the purity of the distilled product does not meet the requirements. This is addressed by setting up a foredistillation tank to collect the product and returning it to the transfer tank for recirculation and distillation until the product meets the standards. Once this is achieved, a valve controls the transfer of the product to the finished product tank for collection, ensuring the final high purity. A two-stage condenser series condenser condenses the vapor, ensuring that all the product is fully condensed. Furthermore, a negative pressure pipeline connected to the second-stage condenser removes non-condensable gases, preventing any impact on the purity of the final product. Attached Figure Description

[0016] Figure 1 This is a system schematic diagram of the present invention.

[0017] In the diagram: 1. Feed pump; 2. Heat exchanger; 3. Thin-film evaporator; 4. Transfer tank; 5. Circulation pump; 6. Distillation column; 7. First condenser; 8. Second condenser; 9. Cooler; 10. Fore-distillation tank; 11. Finished product tank; 12. Negative pressure pipeline; 13. Online sampling port. Detailed Implementation

[0018] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings: like Figure 1As shown, a high-purity alkyl tertiary amine crude product distillation system consists of a feed pump 1, a heat exchanger 2, a thin-film evaporator 3, a transfer tank 4, a circulation pump 5, a distillation column 6, a first condenser 7, a second condenser 8, a cooler 9, a fore-distillation tank 10, a finished product tank 11, and related pipes and valves, etc., and is used for the distillation of alkyl tertiary amine crude product.

[0019] Crude alkyl tertiary amines are fed from the reactor into the material channel of heat exchanger 2 via feed pump 1. After preheating in heat exchanger 2, the crude product enters thin-film evaporator 3 for evaporation. Preheating reduces energy consumption during evaporation. Thin-film evaporator 3 uses heat transfer oil for heat exchange. The evaporated product then enters distillation column 6 for further distillation. As the product and evaporated high-boiling-point substances rise in distillation column 6, alcohols and other high-boiling-point substances, along with some of the product, condense and reflux to the bottom of the column. The vapor from the product enters the heat exchange medium channel of heat exchanger 2 from the top of the column to preheat the crude product fed by feed pump 1. The preheated vapor enters the first condenser 7 for condensation and liquefaction. Non-condensable gases in the first condenser 7 enter the second condenser 8 for further condensation. The condensed product from heat exchanger 2 and both condensers refluxes back to the reflux port of distillation column 6 via a three-way control valve, with a portion sent to cooler 9 for further cooling. Non-condensable gases in the second condenser 8 are discharged and collected through negative pressure pipe 12.

[0020] After being cooled by cooler 9, the finished product flows to the forerunner 10 or the finished product tank 11 through pipes and valves. In the early stages of the reaction, because the system has not yet reached equilibrium, the purity of the distilled product does not yet meet high-purity requirements. Therefore, the initial distillate is sent to the forerunner 10 for collection via valves. The forerunner 10 is located above the intermediate tank 4, and the finished product in the forerunner 10 returns directly to the intermediate tank 4 through pipes. After a period of distillation, once the sampling results from the online sampling port 13 at the bottom of cooler 9 meet the standards, the finished product is sent to the finished product tank 11 for collection. The forerunner 10 and the finished product tank 11 are also connected to negative pressure pipes 12 to promptly remove internal gases and ensure unobstructed gas flow throughout the system.

[0021] The transfer tank 4 is used to collect the residual liquid at the bottom of the thin-film evaporator 3 and the distillation column 6 and re-evaporate it, ensuring that the finished product is completely collected. The transfer tank 4 is equipped with a jacket and circulated with hot water for insulation. A circulation pump 5 is installed on the outside of the transfer tank 4, which circulates the liquid inside into the thin-film evaporator 3 for evaporation. After distillation, the residual liquid in the transfer tank is sent to the slag discharge vessel for treatment by the circulation pump 5. The feed pump sends the finished product in the finished product tank 11 to the storage tank.

Claims

1. A high-purity alkyl tertiary amine crude product distillation system, comprising a thin-film evaporation unit, a distillation column, and a cooler unit, characterized in that, The thin-film evaporation unit includes a feed pump, a heat exchanger, a thin-film evaporator, and a transfer tank. The crude product is fed into the heat exchanger via a pipeline from the feed pump. After heat exchange in the heat exchanger, the crude product enters the thin-film evaporator for evaporation. The gas outlet of the thin-film evaporator is connected to the gas inlet of the distillation column. The bottom of the thin-film evaporator and the bottom of the distillation column are connected to the transfer tank via pipelines and valves. The vapor outlet at the top of the distillation column is connected to the heat exchange channel of the heat exchanger and, through the heat exchange channel, to a cooler unit. The cooler unit includes a condenser and a cooler. The condenser is connected to the heat exchange channel of the heat exchanger. The bottom of the condenser is connected to the reflux port of the distillation column and the cooler via a three-way control valve and pipelines. The cooler is connected to a fore-distillation tank and a finished product tank via pipelines and valves. The bottom of the fore-distillation tank is connected to the transfer tank via a pipeline.

2. The high-purity alkyl tertiary amine crude distillation system according to claim 1, characterized in that, The cooler unit includes two condensers connected in series, and circulating cooling water flows through the condensers.

3. The high-purity alkyl tertiary amine crude distillation system according to claim 2, characterized in that, The vapor in the heat exchanger enters the first-stage condenser, and the liquefied product in the heat exchanger enters the reflux port of the distillation column or the cooler through the pipeline and the three-way control valve.

4. The high-purity alkyl tertiary amine crude distillation system according to claim 1, characterized in that, A circulation pump is installed on the outside of the transfer tank. The circulation pump draws high-boiling-point substances from the transfer tank and circulates them into the thin-film evaporator.

5. The high-purity alkyl tertiary amine crude distillation system according to claim 4, characterized in that, The transfer tank is equipped with a jacket on its outside, and circulating hot water flows through the jacket.

6. The high-purity alkyl tertiary amine crude distillation system according to claim 1, characterized in that, It includes one or two thin-film evaporators connected in series, wherein the heat exchange medium of the thin-film evaporator is heat transfer oil.

7. The high-purity alkyl tertiary amine crude distillation system according to claim 1, characterized in that, The foredistillation tank, the finished product tank, and the second-stage condenser are each connected to a negative pressure pipeline.

8. The high-purity alkyl tertiary amine crude distillation system according to claim 1, characterized in that, The foredistillation tank is located above the transfer tank.

9. The high-purity alkyl tertiary amine crude distillation system according to claim 1, characterized in that, The cooler's output port is equipped with an online sampling port.

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