CN-116510335-B - Trichloroethylene rectification separation device and method

CN116510335BCN 116510335 BCN116510335 BCN 116510335BCN-116510335-B

Abstract

The invention relates to the technical field of trichloroethylene and discloses a trichloroethylene rectification separation device and method, wherein the device comprises a desorption tower kettle liquid tank, the output end of the desorption tower kettle liquid tank is connected with a low-boiling tower, the output end of the low-boiling tower is respectively connected with a low-boiling tower reflux tank and a trichloroethylene tower, the output end of the low-boiling tower reflux tank is communicated with the input end of the low-boiling tower, and the output end of the trichloroethylene tower is connected with a TCE tower reflux tank and a TCE intermediate tank. According to the method, in the trichloroethylene rectification separation method, the TCE stirring tank is designed, and the silver ammonia solution and the allochroic silica gel are added into the stirring tank, so that acidic impurities contained in the trichloroethylene in the rectification process can be removed, secondary purification of the trichloroethylene after the rectification process is realized, and phenomena of easy decomposition and instability of the trichloroethylene in the later period in actual use are reduced, so that the surface of a cleaned device is corroded, cleaning equipment is corroded, and the performance of the device and the condition of the cleaning equipment are directly damaged.

Inventors

TIAN SHIJING
LI BIN
YANG FUGUO
GUAN WEI
WANG QIANG
HOU XINYU

Assignees

重庆市映天辉氯碱化工有限公司

Dates

Publication Date: 20260505
Application Date: 20230427

Claims (4)

1. The utility model provides a trichloroethylene rectification separator, includes analytic tower cauldron fluid reservoir, its characterized in that: the output end of the liquid tank of the resolving tower kettle is connected with a low-boiling tower, the output end of the low-boiling tower is respectively connected with a low-boiling tower reflux tank and a trichloroethylene tower, the output end of the low-boiling tower reflux tank is communicated with the input end of the low-boiling tower, the output end of the trichloroethylene tower is connected with a TCE tower reflux tank and a TCE intermediate tank, the output end of the TCE tower reflux tank is communicated with the input end of the trichloroethylene tower, the output end of the TCE intermediate tank is connected with a TCE finished product tank and a TCE stirring tank, the output end of the TCE stirring tank is communicated with the input end of the trichloroethylene tower, the resolving tower kettle tank is used for storing the resolving tower kettle tank condensed by a resolving tower cooler, a low-boiling tower feed pump is arranged between the low-boiling tower and the resolving tower kettle tank, a low-boiling tower reboiler and a low-boiling tower Quan Ning device is arranged on the low-boiling tower, the low-boiling tower is used for extracting low-boiling matters in the kettle liquid tank of the resolving tower, a trichloroethylene tower feeding pump is arranged between the trichloroethylene tower and the low-boiling tower, a trichloroethylene tower reboiler, a trichloroethylene tower total condenser, a trichloroethylene tower tail cooler, a tail gas fan and an activated carbon filter are arranged on the trichloroethylene tower, wherein the trichloroethylene tower tail cooler, the tail gas fan and the activated carbon filter can discharge waste gas which is not condensed when being condensed by the trichloroethylene tower Quan Ning, the TCE tower reflux tank is used for temporarily storing the low-boiling tower liquid condensed after the waste gas is discharged, a TCE tower reflux pump is arranged between the TCE tower reflux tank and the trichloroethylene tower, the TCE tower reflux pump can reflux the internal low-boiling tower liquid to the trichloroethylene tower to form the trichloroethylene tower liquid, a TCE cooler is arranged between the TCE middle tank and the trichloroethylene tower, the TCE cooler can inject trichloroethylene tower kettle liquid into the TCE intermediate tank, a TCE stirring tank reflux pump is arranged between the TCE stirring tank and the trichloroethylene tower, and the TCE stirring tank is used for removing impurities in the trichloroethylene tower kettle liquid and purifying.
2. The trichloroethylene rectification and separation device according to claim 1, wherein the TCE finished product tank is used for storing the trichloroethylene after rectification and purification for later sale.
3. The trichloroethylene rectifying and separating device according to claim 1, further comprising an intermediate tower, wherein the input end of the intermediate tower is connected with the output end of the trichloroethylene tower, the output end of the intermediate tower is connected with an intermediate tower reflux tank and a PCE tower, and the output end of the PCE tower is connected with a PCE tower reflux tank and a tetrachloroethylene storage tank.
4. A trichloroethylene rectification separation method, which comprises the trichloroethylene rectification separation device as defined in any one of claims 1 to 3, and is characterized by comprising the following specific steps: injecting the tower bottom liquid in the resolving tower into a tower bottom liquid tank of the resolving tower, then feeding the tower bottom liquid into a low-boiling tower for low boiling, injecting low-boiling matters extracted from the tower top of the low-boiling tower into a low-boiling tower reflux tank, and refluxing the tower bottom liquid into the low-boiling tower through the low-boiling tower reflux tank to obtain the tower bottom liquid of the low-boiling tower; Injecting the internal kettle liquid of the low-boiling tower into a trichloroethylene tower, heating, controlling the temperature of an outlet of the tower top to be 83-84 ℃, passing through a TCE tower Quan Ning, entering a TCE tower reflux tank, and discharging the non-condensable part into the atmosphere; Injecting trichloroethylene in the reflux tank in the step two into a TCE intermediate tank, then purifying the trichloroethylene in the TCE intermediate tank for one time, mechanically stirring the trichloroethylene and distilled water for 2 hours, wherein the distilled water contains 2% -5% of silver-ammonia solution, standing for 30 minutes for layering, sucking the upper water, repeating the above operation for several times, and then checking the silver-ammonia reduction object index until the silver-ammonia reduction object reaches the qualification of clarification without turbidity; Adding a certain amount of 1/10 volume ratio of color-changing silica gel into the trichloroethylene after primary purification, enabling the silica gel to be blue, fully shaking for 2 hours, enabling trace water to be adsorbed by the silica gel, standing and filtering, taking out the trichloroethylene, checking whether the trichloroethylene meets the index, transferring the trichloroethylene into a TCE tower again for heating, controlling the outlet temperature of the tower top to be 83-84 ℃, then passing through a TCE tower Quan Ning device, enabling condensate to enter a TCE tower reflux tank, enabling 99.99% of trichloroethylene product in the TCE tower reflux tank to enter a trichloroethylene metering tank after being subjected to acid removal through a TCE cooler and an active alumina filter, adding a stabilizer into the metering tank, and sending the trichloroethylene into a TCE intermediate tank and a TCE finished product tank after being uniformly mixed.

Description

Trichloroethylene rectification separation device and method Technical Field The invention relates to the technical field of trichloroethylene, in particular to a trichloroethylene rectification separation device and a trichloroethylene rectification separation method. Background Trichloroethylene (TCE) is an important chemical raw material, is a solvent with extremely strong dissolving capacity, is industrially used for metal cleaning (degreasing thoroughly) and fiber degreasing and cleaning of electronic elements, can be used as a raw material intermediate for producing tetrachloroethylene, chloroacetic acid, dichloroacetyl chloride, octachlorodipropyl ether, HCFC-123, HCFC-124, HFC-125, HFC-134a and the like, and is also used as an extractant, a solvent and a low-temperature heat conducting oil medium. With the rapid development of the electronic industry and the metal processing industry in recent years, the demand of trichloroethylene is continuously increased, the annual import amount of trichloroethylene is more than 4 ten thousand tons, 90% of the trichloroethylene is used as cleaning agents, in addition, an important factor for pulling the continuous growth of the demand of trichloroethylene is that the trichloroethylene is used as an important raw material of an environment-friendly refrigerant HFC-134a, the HFC-134a is used as an environment-friendly refrigerant to become the best substitute for the current ODS in the United states and Europe, and in recent years, the industry standard of the application of the HFC-134a in an automobile air conditioner, a refrigerator and a foaming agent is determined by industry standard and regulations in China, so that the demand of the trichloroethylene is required to be changed according to the development of the production technology of the HFC-134a and the popularization of the market range in China, in general, and the trichloroethylene has good market prospect in China no matter being used as an organic solvent or an intermediate product, and belongs to a chlorine product which is in shortage and needs to develop in the market. At present, the trichloroethylene process technology is fully mature, the improvement and maturation of the new technology provides powerful guarantee for the construction of trichloroethylene devices, but some crude trichloroethylene, such as high-grade pure and chemically pure trichloroethylene, contains a certain amount of water, free chlorine and silver ammonia reducing substances, so that the trichloroethylene is decomposed rapidly to generate hydrogen chloride which is acidic, and is easy to decompose and unstable in practical use, further has corrosion effect on the surface of cleaned devices, and corrodes cleaning equipment to directly damage the performance of the devices and the cleaning equipment, and although a plurality of methods exist in the method for producing the trichloroethylene, any manufacturing method has the problems that various byproducts with different chlorinations are contained in the crude trichloroethylene, so that the cleaning of the trichloroethylene in the electronic industry is influenced, and meanwhile, the bottom of a resolution tower of the trichloroethylene can generate kettle liquid containing the trichloroethylene in the production process, and the external environment can be polluted if the trichloroethylene is directly discharged. Therefore, we propose a trichloroethylene rectification separation device and method for solving the above problems. Disclosure of Invention (One) solving the technical problems Aiming at the defects of the prior art, the invention designs the TCE stirring tank in the trichloroethylene rectification separation device and method, and adds silver ammonia solution and allochroic silica gel into the stirring tank to remove acidic impurities contained in the trichloroethylene in the rectification process, so as to realize secondary purification of the trichloroethylene after the rectification process, reduce the phenomena of easy decomposition and instability of the trichloroethylene in the later period when in actual use, further have corrosion effect on the surface of a cleaned device, corrode the cleaning device, directly damage the performance of the device and the advantages of the cleaning device, solve the problems that the prior trichloroethylene technology is completely mature, the improvement and the maturity of the new technology provide powerful guarantee for the construction of the trichloroethylene device, but some crude trichloroethylene, such as high-grade pure and chemically pure trichloroethylene, has a certain amount of water, free chlorine and silver ammonia reducing substances, accelerates the decomposition of the trichloroethylene, generates hydrogen chloride, is acidic, is easy to decompose and unstable in the actual use, further has corrosion effect on the surface of the cleaned device, corrodes the cleaning device, directly damages the perfor