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CN-224220756-U - Continuous production system for diethyl maleate

CN224220756UCN 224220756 UCN224220756 UCN 224220756UCN-224220756-U

Abstract

The utility model discloses a continuous production system of diethyl maleate, which comprises a reaction rectifying tower, a benzene-water separation tank, a vacuum rectifying tower, a benzene removal tower and an ethanol rectifying tower. The utility model comprises a vacuum rectifying tower, a benzene removal tower and an ethanol rectifying tower, wherein the vacuum rectifying tower is used for purifying tower kettle materials in the reaction rectifying tower to improve the purity of products, the benzene removal tower is used for removing reboiling agent benzene in water phase materials in a benzene-water separation tank, the reboiling agent benzene is recycled to the benzene-water separation tank for reuse, and the ethanol rectifying tower is used for separating ethanol from water in the materials in the benzene-water separation tank to recycle the ethanol, so that the utilization rate of the raw materials is effectively improved.

Inventors

  • ZHANG LIN

Assignees

  • 上海福沌工程技术有限公司

Dates

Publication Date
20260512
Application Date
20250427

Claims (6)

  1. 1. The continuous production system of diethyl maleate is characterized by comprising a reaction rectifying tower (1), a benzene-water separation tank (2), a vacuum rectifying tower (3), a benzene removal tower (4) and an ethanol rectifying tower (5); The upper feed inlet of the reaction rectifying tower body is connected with a lateral line feed pipeline (6), the top discharge outlet of the reaction rectifying tower body is connected with a first condenser (7), the discharge outlet of the first condenser is connected with the feed inlet of the benzene-water separation tank through a pipeline, and the bottom discharge outlet of the reaction rectifying tower body is connected with the middle feed inlet of the vacuum rectifying tower body through a pipeline; The benzene phase outlet on the benzene-water separation tank is connected with the top reflux port of the reaction rectifying tower through a pipeline, and the water phase outlet on the benzene-water separation tank is connected with the middle feed inlet of the tower body of the debenzolization tower through a pipeline; The top light component discharge port of the vacuum rectifying tower is connected with a second condenser (8), the discharge port of the second condenser is connected with a light component discharge pipeline (9), the bottom discharge port of the vacuum rectifying tower is connected with a heavy component discharge pipeline (10), and the middle part of the tower body of the vacuum rectifying tower is connected with a lateral line discharge pipeline (11); The tower top discharge port of the benzene removal tower is connected with a third condenser (12), the discharge port of the third condenser is connected with the feed port of the benzene-water separation tank through a pipeline, and the tower bottom discharge port of the benzene removal tower is connected with the feed port in the middle of the tower body of the ethanol rectifying tower through a pipeline; the top of the tower discharge gate of ethanol rectifying column is connected with fourth condenser (13), the discharge gate of fourth condenser is connected with ethanol discharging pipe (14), and the top of the tower discharge gate of ethanol rectifying column is connected with waste pipe (15).
  2. 2. The continuous production system of diethyl maleate according to claim 1, further comprising a lateral line buffer tank (16), wherein the feed inlet of the lateral line buffer tank is connected with the middle discharge outlet of the tower body of the reactive distillation tower through a pipeline, and the discharge outlet of the lateral line buffer tank is respectively connected with the upper feed inlet and the lower feed inlet of the tower body of the reactive distillation tower through pipelines.
  3. 3. The continuous production system of diethyl maleate according to claim 1, wherein the outlet of the second condenser is further connected to the top reflux port of the vacuum rectifying tower through a pipeline.
  4. 4. The continuous production system of diethyl maleate according to claim 1, wherein the outlet of the third condenser is further connected to the top reflux of the debenzolization column via a pipeline.
  5. 5. The continuous production system of diethyl maleate according to claim 1, wherein the outlet of the fourth condenser is further connected to the top reflux port of the ethanol rectifying tower through a pipeline.
  6. 6. The continuous production system of diethyl maleate according to claim 1, wherein at least four layers of packing are arranged in the reaction rectifying tower, at least three layers of packing are arranged in the vacuum rectifying tower, and at least three layers of packing are arranged in the debenzolization tower and the ethanol rectifying tower.

Description

Continuous production system for diethyl maleate Technical Field The utility model relates to the technical field of production of diethyl maleate, in particular to a continuous production system of diethyl maleate. Background The chemical formula of the diethyl maleate is C 8H12O4, is colorless transparent oily liquid, and can be used as a high molecular compound monomer and a pesticide intermediate. The maleic acid diethyl ester is synthesized by taking maleic anhydride and ethanol as raw materials through esterification reaction. The China patent with application publication number CN114570052A and application publication number 2022, 6 and 3 discloses a method and a device for continuously producing diethyl maleate, wherein the method comprises a maleic anhydride dissolution kettle, a material feeding dissolution kettle inlet is connected to the top end of the maleic anhydride dissolution kettle, a pipeline is arranged at the bottom end of the maleic anhydride dissolution kettle and connected with a conveying pump A, a rectifying tower body, one side of the rectifying tower body is provided with a pipeline which is connected and communicated with the conveying pump A, and four groups of feed inlets are arranged outside the rectifying tower body. The device has the following defects that (1) the product of the rectifying tower is not subjected to purification treatment, the purity of the obtained diethyl maleate is low (98.8 percent and 99.1 percent), and (2) condensate water layer wastewater in the condensate layering tower is discharged from a wastewater outlet and is sent to an environmental protection station, is sent to the next environmental protection station after harmless treatment, and is not recycled, so that raw materials (benzene and ethanol in the wastewater) are wasted. Disclosure of utility model The utility model aims to solve the problems of the prior art diethyl maleate production device, and provides a continuous production system of diethyl maleate, which has stable operation and good production continuity, can improve the purity of diethyl maleate and the utilization rate of raw materials, and is suitable for large-scale production. The technical scheme is that the continuous production system of the diethyl maleate comprises a reaction rectifying tower, a benzene-water separation tank, a vacuum rectifying tower, a benzene removal tower and an ethanol rectifying tower, wherein a side line feed pipeline is connected to a feed port at the upper part of a tower body of the reaction rectifying tower, a first condenser is connected to a discharge port at the top of the reaction rectifying tower, a discharge port of the first condenser is connected with a feed port of the benzene-water separation tank through a pipeline, a discharge port at a tower bottom of the reaction rectifying tower is connected with a feed port at the middle part of the tower body of the vacuum rectifying tower through a pipeline, a benzene phase outlet on the benzene-water separation tank is connected with a return port at the top of the reaction rectifying tower through a pipeline, a water phase outlet on the benzene-water separation tank is connected with a feed port at the middle part of the benzene removal tower through a pipeline, a second condenser is connected to a light component pipeline, a heavy component discharge pipeline is connected to a discharge port at the top of the vacuum rectifying tower, a discharge port at the middle part of the benzene removal tower is connected with a discharge port at the top of the four condenser, and an ethanol outlet at the top of the four condenser is connected with a discharge port at the top of the benzene removal tower through a condenser. The method comprises the steps of taking maleic anhydride and ethanol as raw materials, carrying out esterification reaction in a reaction rectifying tower, separating the product diethyl maleate from water, carrying out azeotropic distillation by introducing entrainer benzene, carrying water and a small amount of ethanol out of a reaction system, separating entrainer benzene by a benzene-water separation tank, re-refluxing the entrainer benzene into the tower, purifying tower bottom materials in the reaction rectifying tower by adopting a vacuum rectification technology (the vacuum degree in the tower is 2-2.1 kPa), and finally obtaining the product diethyl maleate with the purity of more than 99.9wt%, wherein the product purity is high. Preferably, the device further comprises a lateral line buffer tank, wherein a feed inlet of the lateral line buffer tank is connected with a discharge port in the middle of the tower body of the reactive distillation tower through a pipeline, and the discharge port of the lateral line buffer tank is respectively connected with a feed inlet in the upper part of the tower body and a feed inlet in the lower part of the tower body of the reactive distillation tower through pipelines. The side line bu