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CN-224208045-U - Byproduct hydrochloric acid filtering device for phosgenation product

CN224208045UCN 224208045 UCN224208045 UCN 224208045UCN-224208045-U

Abstract

The utility model discloses a device for filtering byproduct hydrochloric acid of a phosgenation product, and aims to solve the problems of high cost, high pollution risk, non-ideal treatment effect and the like in the traditional treatment method. The device comprises a first resin column and a second resin column, and adopts a specific resin combination technology to cooperatively remove sulfate radical, ferric ions and organic pollutants in byproduct hydrochloric acid through physical adsorption of resin, thereby remarkably improving the chromaticity and purity of the hydrochloric acid. The device adopts a PLC automatic control system, and the valve and the pump are automatically adjusted to start and stop according to the liquid level and the transparency of hydrochloric acid, so that the stability and the high efficiency of the purification process are ensured. In addition, through the COD on-line monitoring of backwash water, the environmental protection and the high efficiency of backwash process are ensured, and the backwash water can be recycled after being treated, thereby realizing zero discharge of wastewater. The utility model has simple structure, convenient operation and high energy efficiency, and is an effective solution for treating the byproduct hydrochloric acid in the phosgenation reaction process.

Inventors

  • CHEN BO
  • MA XIAOLONG
  • MA XIAOHONG
  • CHEN HUAWEI
  • WU JUNJUN

Assignees

  • 宁夏新安科技有限公司

Dates

Publication Date
20260508
Application Date
20250516

Claims (10)

  1. 1. The device for filtering byproduct hydrochloric acid of a phosgenation product comprises a first resin column (1) and a second resin column (2), and is characterized in that the first resin column (1) and the second resin column (2) have the same structure, a main body is a container with resin arranged inside, a feed inlet is arranged at the top of the container, and a discharge outlet is arranged on the peripheral surface of the lower end of the container; The feeding port of the first resin column (1) is communicated with the feeding pipeline (3), the feeding pipeline (3) is sequentially provided with an electromagnetic valve, a Y-shaped filter (7) and a hydrochloric acid pump (6) from the feeding direction, and the electromagnetic valve is arranged at the joint of the feeding pipeline (3) and the feeding port of the first resin column (1); The pumping direction of the hydrochloric acid pump (6) is from the feeding direction to the first resin column (1); the second resin column (2) is communicated and connected with the first resin column (1) through a lifting pipeline (4), one end of the lifting pipeline (4) is connected with a discharge port of the first resin column (1), and the other end of the lifting pipeline is communicated and connected with a feed port of the second resin column (2), and electromagnetic valves are respectively arranged at the connection positions of the lifting pipeline (4) and the first resin column (1) and the second resin column (2); The discharge port of the second resin column (2) is communicated and connected with a discharge pipeline (5), and an electromagnetic valve is arranged on the discharge pipeline (5).
  2. 2. The apparatus for filtering hydrochloric acid as recited in claim 1, wherein said first resin column (1) comprises: A resin container (11) in a can; A resin layer (12) fixedly connected to the inside of the resin container (11) and radially filling the container, and having spaces with the upper and lower ends of the resin container (11) respectively; The discharge hole of the first resin column (1) or the second resin column (2) is positioned at the lower end position of the resin layer (12).
  3. 3. The device for filtering byproduct hydrochloric acid of a phosgenation product according to claim 2 is characterized in that fixed gauze (13) is respectively arranged on the upper end face and the lower end face of the resin layer (12), the fixed gauze (13) is fixedly connected to the inner wall of the resin container (11), and the outline of the outer edge of the fixed gauze (13) is identical to the cross section of the resin layer (12).
  4. 4. The filtering device for the byproduct hydrochloric acid of the phosgenation product according to claim 2, wherein a liquid distributor (14) is fixed in the resin container (11), and the liquid distributor (14) is positioned at the upper end of the resin layer (12) and at the lower end of the feed inlet.
  5. 5. The device for filtering byproduct hydrochloric acid of phosgenation products according to claim 2 is characterized in that a discharging filter plate (15) is fixedly connected to the inside of the resin container (11), the discharging filter plate (15) is a plate-shaped piece with a plurality of through holes formed in the plate-shaped piece, the discharging filter plate (15) is located below the resin layer (12), and the edge outline of the discharging filter plate (15) is identical to the cross section shape of the inner wall of the resin container (11).
  6. 6. A filtration device for the byproduct hydrochloric acid of a phosgenation product according to any one of claims 2 to 5, wherein a liquid level sensor (16) is provided in each of the first resin column (1) and the second resin column (2).
  7. 7. The device for filtering byproduct hydrochloric acid of a phosgenation product according to claim 6, wherein backwash water inlets are respectively arranged at the lower end positions of the first resin column (1) and the second resin column (2), backwash water outlets are respectively arranged on the peripheral surface of the upper end, and the backwash water outlets are positioned at the upper end position of the resin layer (12); The backwash water outlet and backwash water inlet of the first resin column (1) and the second resin column (2) are communicated and connected with a backwash system (8).
  8. 8. The apparatus for filtering hydrochloric acid as recited in claim 7, wherein said back flushing system (8) comprises: the device comprises a backwash pump (81) communicated and connected with a backwash water source, wherein the pumping direction of the backwash pump (81) is opposite to that of a hydrochloric acid pump (6), and an electromagnetic valve is arranged at the water inlet end of the backwash pump (81); One end of the backwash water inlet pipe (82) is communicated and connected with a backwash water inlet of the second resin column (2), and the other end of the backwash water inlet pipe is connected with a water outlet end of the backwash pump (81); One end of the backwash lifting pipe (83) is communicated and connected with a backwash water outlet of the second resin column (2), and the other end of the backwash lifting pipe is communicated and connected with a backwash water inlet of the first resin column (1), and electromagnetic valves are respectively arranged at the joints of the backwash lifting pipe (83) and the first resin column (1) and the second resin column (2); A backwash outlet pipe (84) with one end communicated with a backwash outlet of the first resin column (1), wherein an electromagnetic valve is arranged on the backwash outlet pipe (84); and a COD on-line monitor (85) arranged on the backwashing water outlet pipe (84).
  9. 9. The device for filtering byproduct hydrochloric acid of a phosgenation product according to claim 8, wherein a backwash water source of the backwash pump (81) is a backwash water tank (86), the backwash pump (81) is connected with the backwash water tank (86) in a communicating way through a pipeline, and the tail end of the pipeline extends into the bottom of the backwash water tank (86).
  10. 10. The device for filtering byproduct hydrochloric acid of a phosgenation product according to claim 9, wherein one end of the backwash water outlet pipe (84) which is not connected with the first resin column (1) is connected with the backwash water tank (86) in a communicating way, the tail end of the backwash water outlet pipe (84) is positioned at the top position of the backwash water tank (86), and a second COD on-line monitor (87) is arranged in the backwash water tank (86).

Description

Byproduct hydrochloric acid filtering device for phosgenation product Technical Field The utility model relates to the field of chemical industry, in particular to a device for filtering byproduct hydrochloric acid of a phosgenation product. Background The phosgenation reaction is an important synthesis process widely applied to the production of high polymer and fine chemical products such as polycarbonate, isocyanate and the like. The reaction is usually carried out by taking phosgene (generated by reacting carbon monoxide with chlorine) as raw material, respectively reacting with hydroxyl-containing compounds (such as phenols and alcohols) or amino-containing compounds (such as amines) under liquid phase or gas phase conditions, and generating corresponding target products such as carbonic esters and isocyanates. During this reaction, phosgene acts as an active intermediate, with the addition or substitution reaction being accompanied by the release of a large amount of hydrogen chloride gas. In order to control the pressure of the device and improve the safety of the reaction, the generated hydrogen chloride gas is usually subjected to water absorption through a tail gas absorption tower to form byproduct hydrochloric acid with a concentration in the range of ten to thirty percent. Although the byproduct hydrochloric acid has higher acidity and certain utilization value, the byproduct hydrochloric acid often contains various impurities due to factors such as complex reaction system, various raw materials, equipment materials and the like. The main pollutants comprise organic matters (such as benzene, toluene, aniline and the like) remained in the reaction, sulfides (forming sulfate impurities) entrained in the raw materials and iron ions (ferrous ions and ferric ions) introduced by equipment corrosion. Among these, the presence of ferric ions often results in hydrochloric acid exhibiting a yellow to tan appearance, making it unusable for downstream applications such as electronic grade, pharmaceutical grade, etc. where acid purity and color are critical. In addition, the sulfate radical content in the byproduct hydrochloric acid often exceeds the industrial grade use standard, and the popularization and the use of the byproduct hydrochloric acid serving as raw material acid are further limited. The traditional byproduct hydrochloric acid purifying treatment process, such as filtration, oxidation, adsorption, sedimentation and the like, can remove particles, ferric oxide ions or partial organic impurities to a certain extent, but has the defects that firstly, a large amount of chemical reagents (such as barium chloride) are needed to precipitate sulfate radicals and ferric ions, the hidden danger of secondary pollution and the high treatment cost exist, secondly, colloidal ferric hydroxide in the precipitate is difficult to thoroughly remove through common filtration, so that the residual iron content still possibly exceeds the standard, and finally, the process is complex, the energy consumption is high, the automation degree is low, the industrialization continuous operation is not facilitated, and finally, the chromaticity improvement is limited, and the removing capability of the adsorption material on low-concentration dissolved aromatic organic matters is not strong. Therefore, aiming at the deep purification requirement of byproduct hydrochloric acid generated in the phosgenation reaction process, development of a purification device which has simple structure, automatic control, high operation efficiency, remarkable purification effect and avoids the use of chemical agents is needed to realize the cooperative removal of metal ions, sulfate radicals and organic pollutants in the byproduct hydrochloric acid, and simultaneously improve the color quality and the recycling value of the byproduct hydrochloric acid. Disclosure of utility model In order to solve the problems, the utility model provides a filtering device for the byproduct hydrochloric acid of the phosgenation product. The utility model is realized by the following technical scheme: The utility model relates to a byproduct hydrochloric acid filtering device for a phosgenation product, which comprises a first resin column and a second resin column, wherein the first resin column and the second resin column have the same structure, a main body is a container with resin arranged inside, a feed inlet is arranged at the top of the container, and a discharge outlet is arranged on the peripheral surface of the lower end position of the container; The feeding port of the first resin column is communicated with a feeding pipeline, the feeding pipeline is sequentially provided with an electromagnetic valve, a Y-type filter and a hydrochloric acid pump from the feeding direction, and the electromagnetic valve is arranged at the joint of the feeding pipeline and the feeding port of the first resin column; the pumping direction of the hydrochloric aci