CN109369385B - Preparation method of ethyl trifluoroacetate - Google Patents
Preparation method of ethyl trifluoroacetate Download PDFInfo
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- CN109369385B CN109369385B CN201811337714.6A CN201811337714A CN109369385B CN 109369385 B CN109369385 B CN 109369385B CN 201811337714 A CN201811337714 A CN 201811337714A CN 109369385 B CN109369385 B CN 109369385B
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Abstract
The invention discloses a preparation method of ethyl trifluoroacetate, which comprises the following steps: 1) introducing sulfur trioxide and trifluorotrichloroethane into an oxo reaction kettle for two times; 2) allowing trifluoroacetyl chloride, byproducts and part of raw materials to enter a stripping kettle for stripping, condensing and separating; 3) conveying the separated trifluoroacetyl chloride to a hydrolysis absorption system, and condensing and refluxing part of raw materials to an oxo reaction kettle; 4) the rectified raw material returns to the oxo reaction kettle; sulfuryl chloride, pyrosulfuryl chloride and impurities are to be hydrolyzed; 5) obtaining a trifluoroacetic acid crude product, and rectifying to obtain trifluoroacetic acid; 6) adding trifluoroacetic acid into an esterification kettle; 7) obtaining the finished product of the trifluoroacetic acid ethyl ester. According to the invention, the reactants are added in several times, the reaction conversion rate is higher, a good reaction foundation is laid for the subsequent reaction, the reaction condition is mild, the consumption of concentrated sulfuric acid is greatly reduced, and the corrosivity to equipment is reduced; the efficiency of separating trifluoroacetyl chloride is higher by adding fibers into the frozen saline.
Description
Technical Field
The invention belongs to the technical field of preparation of ethyl trifluoroacetate, and particularly relates to a preparation method of ethyl trifluoroacetate.
Background
Ethyl trifluoroacetate is an important organic fluorine intermediate, and has wide application in synthesizing various fluorine-containing medicines, pesticides, liquid crystals, fuels and other products, such as the synthesis of a cardiovascular and cerebrovascular medicine, namely the laninopril.
The traditional method for preparing ethyl trifluoroacetate is obtained by using trifluoroacetic acid as a raw material and performing esterification reaction with ethanol under the catalysis of concentrated sulfuric acid, and due to unreasonable arrangement among reaction steps, the yield of synthesis in the whole process is low, the requirement on equipment is high, and adverse effects on environment can be generated.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides the preparation method of the ethyl trifluoroacetate, which has the advantages of high finished product yield, good finished product quality, low requirement on preparation equipment, environmental protection and energy conservation.
The technical scheme adopted by the invention for solving the technical problems is as follows: a preparation method of ethyl trifluoroacetate comprises the following steps:
1) introducing sulfur trioxide and trifluorotrichloroethane in a mass ratio of 1:1 into an oxo reaction kettle, controlling the temperature of the oxo reaction kettle to be 58-62 ℃, and reacting for 20-30 min;
2) introducing sulfur trioxide and trifluorotrichloroethane in a mass ratio of 1:2 into an oxo reaction kettle, controlling the temperature of the oxo reaction kettle to be 60-65 ℃, and reacting for 10-40 min;
3) the reaction products trifluoroacetyl chloride and by-products sulfuryl chloride and pyrosulfuryl chloride in the steps 1) and 2) enter a stripping kettle along with part of raw materials of sulfur trioxide and trifluorotrichloroethane from a gas phase outlet of the oxo reaction kettle, and are subjected to stripping condensation separation at the temperature of 63-65 ℃;
4) conveying trifluoroacetyl chloride separated from the stripping kettle to a hydrolysis absorption system from a top outlet, condensing and refluxing part of raw materials to an oxo reaction kettle, conveying sulfuryl chloride and pyrosulfuryl chloride to the bottom of a circulating distillation kettle, and placing the part of the liquid level in the circulating distillation kettle, which exceeds a lug, into a sulfuryl chloride intermediate tank;
5) sulfuryl chloride, pyrosulfuryl chloride, trichlorotrifluoroethane and sulfur trioxide in the sulfuryl chloride intermediate tank are pumped into a circulating distillation kettle, the circulating distillation kettle is controlled to be rectified at 48-52 ℃, and the rectified raw materials of sulfur trioxide and trichlorotrifluoroethane return to the oxo reaction kettle; sulfuryl chloride, pyrosulfuryl chloride and impurities in the sulfuryl chloride intermediate tank are cooled to normal temperature and then pumped into a sulfuryl chloride metering high-level tank to be hydrolyzed;
6) removing sulfur trioxide carried by trifluoroacetyl chloride gas through concentrated sulfuric acid, then, entering a water desorption system to obtain a crude product of trifluoroacetic acid, and rectifying the crude product of trifluoroacetic acid in a trifluoroacetic acid rectifying kettle at the kettle bottom temperature of 75-90 ℃ and the kettle top temperature of 68-74 ℃ to obtain trifluoroacetic acid;
7) adding the trifluoroacetic acid obtained in the step 6) into an esterification kettle, taking concentrated sulfuric acid as a catalyst and a dehydrating agent, slowly dropwise adding ethanol, controlling the reaction temperature to be less than 50 ℃, wherein the mass ratio of the trifluoroacetic acid to the ethanol is 3:0.3-1.6, and the mass ratio of the trifluoroacetic acid to the concentrated sulfuric acid is 6: 0.02-0.07;
8) rectifying and condensing the ethyl trifluoroacetate obtained in the step 7) at the conditions of the kettle bottom temperature of 65-90 ℃ and the kettle top temperature of 60-66 ℃ to obtain a finished product of the ethyl trifluoroacetate;
9) hot water is conveyed to a sulfuryl chloride hydrolysis absorption system from a sulfuryl chloride metering high-level tank, byproduct disulfoyl chloride is dripped to the sulfuryl chloride hydrolysis absorption system from the sulfuryl chloride metering high-level tank, the sulfuryl chloride hydrolysis absorption system is controlled to carry out hydrolysis reaction at 63-66 ℃, produced dilute sulfuric acid is collected into a sulfuric acid storage tank, hydrogen chloride gas generated in the hydrolysis process is absorbed by water through a falling film absorber, and obtained hydrochloric acid is collected into a hydrochloric acid storage tank.
Preferably, the hydrolysis absorption system is a four-stage countercurrent hydrolysis absorption system, and comprises a first absorption tower, a second absorption tower, a third absorption tower and a fourth absorption tower, wherein the bottom of the second absorption tower is connected with the top of the first absorption tower, the absorption liquid in the fourth absorption tower is tap water, the absorption liquid in the third absorption tower is the absorption liquid from the fourth absorption tower, and the concentration of the absorption liquid is controlled to be 30-40%; the absorption liquid in the second absorption tower is from the absorption liquid in the third absorption tower, and the concentration of the absorption liquid is controlled to be 70-80%; the absorption liquid in the first absorption tower is from the absorption liquid in the second absorption tower, and the concentration of the absorption liquid is controlled to be 85-95%.
Preferably, the hydrolysis absorption system works intermittently, stays for 0.5 hour after hydrolysis treatment is carried out for 1.5 to 3 hours, and continues to operate circularly.
Preferably, the tail gas is hydrogen chloride gas, and the hydrogen chloride gas is washed by a first-stage water washing tower and a second-stage alkaline washing tower by using a 10% sodium hydroxide solution and then is discharged at high altitude.
Preferably, the stripping tower in the step 4) separates trifluoroacetyl chloride, sulfuryl chloride, pyrosulfuryl chloride and unreacted raw materials through primary water cooling and secondary freezing brine condensation.
Preferably, the freezing temperature of the secondary frozen brine is-5 to-45 ℃, and the freezing time is 20 to 40 min.
Preferably, the secondary frozen saline is added with poplar fiber and eucalyptus fiber, and the total mass of the poplar fiber and the eucalyptus fiber accounts for 2-4% of the frozen saline.
Preferably, the ratio of the poplar fiber to the eucalyptus fiber is 3:6-10, and the beating degree is 25-30SR degrees.
The invention has the beneficial effects that: 1) the structure of the existing equipment is not required to be changed to a great extent, and only a little change is needed to be made on the local process flow; 2) the reactants are added in a plurality of times, the process conditions of the two times are treated differently, the reaction conversion rate is higher, and a good reaction foundation is laid for the subsequent reaction; 3) the reaction condition is mild, the consumption of concentrated sulfuric acid is greatly reduced, and the corrosivity to equipment is reduced; 4) the hydrolysis flow of the hydrolysis absorption system is designed, the concentration of absorption liquid in each absorption tower is strictly controlled, and an intermittent treatment mode is adopted, so that the hydrolysis absorption efficiency is higher, the residual quantity is reduced to the minimum, meanwhile, a relatively long time area is provided for water desorption reaction due to the design of buffer time, and the energy consumption of equipment is reduced; 5) the fiber is added into the frozen brine, so that the efficiency of separating trifluoroacetyl chloride is higher, the temperature of the frozen brine can be kept lower under the condition that strict energy supply is not needed, the temperature can be accurately adjusted, the influence on the yield of the whole process is larger, and the addition amount of the fiber, the selection of the fiber and the beating degree of the fiber have auxiliary functions on the performance of the frozen brine.
Drawings
FIG. 1 is a schematic process flow diagram of the present invention.
Detailed Description
In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example one
1) 2kg of sulfur trioxide passes through an oxo reaction kettle from a storage tank through internal pressure, 2kg of trifluorotrichloroethane passes through the oxo reaction kettle, wherein the sulfur trioxide is heated by introducing hot water at about 70 ℃ into a jacket, the temperature in the oxo reaction kettle is controlled to be 58 ℃, and the reaction is carried out for 20 minutes;
2) 3kg of sulfur trioxide passes through an oxo reaction kettle from a storage tank through internal pressure, 6kg of trifluorotrichloroethane passes through the oxo reaction kettle, the temperature in the oxo reaction kettle is controlled to be 60 ℃, and the reaction is carried out for 10 minutes;
3) the reaction products trifluoroacetyl chloride and by-products sulfuryl chloride and pyrosulfuryl chloride in the steps 1) and 2) enter a stripping kettle along with part of raw materials of sulfur trioxide and trifluorotrichloroethane from a gas phase outlet of the oxo reaction kettle, and are stripped, condensed and separated at 63 ℃;
4) conveying trifluoroacetyl chloride separated from the stripping kettle to a hydrolysis absorption system from a top outlet, condensing and refluxing part of raw materials to an oxo reaction kettle, conveying sulfuryl chloride and pyrosulfuryl chloride to the bottom of a circulating distillation kettle, and placing the part of the liquid level in the circulating distillation kettle, which exceeds a lug, into a sulfuryl chloride intermediate tank;
the hydrolysis absorption system is a four-stage countercurrent hydrolysis absorption system and comprises a first absorption tower, a second absorption tower, a third absorption tower and a fourth absorption tower, wherein the bottom of the second absorption tower is connected with the top of the first absorption tower, the bottom of the third absorption tower is connected with the top of the second absorption tower, the bottom of the fourth absorption tower is connected with the top of the third absorption tower, an absorption liquid in the fourth absorption tower is tap water, the absorption liquid in the third absorption tower is a trifluoroacetic acid solution from the fourth absorption tower, and the concentration of the trifluoroacetic acid solution is controlled to be 30%; the absorption liquid in the second absorption tower is from the absorption liquid in the third absorption tower, and the concentration of the absorption liquid is controlled to be 70%; the absorption liquid in the first absorption tower is from the absorption liquid in the second absorption tower, and the concentration of the absorption liquid is controlled to be 85 percent;
the tail gas discharged from the top of the fourth absorption tower is mainly hydrogen chloride gas, and the hydrogen chloride gas is absorbed by water by adopting a falling film absorption method to prepare hydrochloric acid;
the hydrolysis absorption system works intermittently, the operation is stopped for 0.5 hour after the hydrolysis treatment is carried out for 1.5 hours, the operation is stopped for 0.5 hour after the hydrolysis treatment is continuously carried out for 1.5 hours, and the operation is repeated in a circulating way;
the method comprises the following steps that trifluoroacetyl chloride, sulfuryl chloride, pyrosulfuryl chloride and unreacted raw materials are separated from a stripping tower through primary water cooling and secondary freezing brine condensation, the freezing temperature of the secondary freezing brine is-5 ℃, the freezing time is 20min, poplar fibers and eucalyptus fibers are added into the secondary freezing brine, the total mass of the poplar fibers and the eucalyptus fibers accounts for 2% of the freezing brine, the ratio of the poplar fibers to the eucalyptus fibers is 3:7, and the beating degree of the poplar fibers and the eucalyptus fibers is 25SR degrees;
5) sulfuryl chloride, pyrosulfuryl chloride, trichlorotrifluoroethane and sulfur trioxide in the sulfuryl chloride intermediate tank are pumped into a circulating distillation kettle, the circulating distillation kettle is controlled to be rectified at 48 ℃, and the rectified raw materials of sulfur trioxide and trichlorotrifluoroethane return to the oxo reaction kettle; sulfuryl chloride, pyrosulfuryl chloride and impurities in the sulfuryl chloride intermediate tank are cooled to normal temperature and then pumped into a sulfuryl chloride metering high-level tank to be hydrolyzed;
6) removing sulfur trioxide carried by trifluoroacetyl chloride gas through concentrated sulfuric acid, then, entering a water desorption system to obtain a trifluoroacetic acid crude product, and rectifying the trifluoroacetic acid crude product in a trifluoroacetic acid rectifying kettle under the conditions that the kettle bottom temperature is 85 ℃ and the kettle top temperature is 72 ℃ to obtain trifluoroacetic acid;
7) adding the trifluoroacetic acid obtained in the step 6) into an esterification kettle, taking concentrated sulfuric acid as a catalyst and a dehydrating agent, slowly dropwise adding ethanol, controlling the reaction temperature to be less than 50 ℃, wherein the mass ratio of the trifluoroacetic acid to the ethanol is 3:0.3, and the mass ratio of the trifluoroacetic acid to the concentrated sulfuric acid is 6: 0.02;
8) rectifying and condensing the ethyl trifluoroacetate obtained in the step 7) at the conditions of the kettle bottom temperature of 80 ℃ and the kettle top temperature of 62 ℃ to obtain a finished product of the ethyl trifluoroacetate;
9) hot water is conveyed to a sulfuryl chloride hydrolysis absorption system from a sulfuryl chloride metering high-level tank, byproduct disulfoyl chloride is dripped to the sulfuryl chloride hydrolysis absorption system from the sulfuryl chloride metering high-level tank, the sulfuryl chloride water desorption system is controlled to carry out hydrolysis reaction at 63 ℃, produced dilute sulfuric acid is collected into a sulfuric acid storage tank, hydrogen chloride gas generated in the hydrolysis process is absorbed by water through a falling film absorber, and obtained hydrochloric acid is collected into a hydrochloric acid storage tank.
The purity of the obtained ethyl trifluoroacetate finished product reaches over 99.2 percent, and the yield is about 95 percent.
Example two
1) 4kg of sulfur trioxide passes through an oxo reaction kettle from a storage tank through internal pressure, 4kg of trifluorotrichloroethane passes through the oxo reaction kettle, wherein the sulfur trioxide is heated by introducing hot water at about 70 ℃ into a jacket, the temperature in the oxo reaction kettle is controlled to be 60 ℃, and the reaction is carried out for 25 minutes;
2) 2kg of sulfur trioxide passes through an oxo reaction kettle from a storage tank through internal pressure, 4kg of trifluorotrichloroethane passes through the oxo reaction kettle, the temperature in the oxo reaction kettle is controlled to be 62 ℃, and the reaction is carried out for 15 minutes;
3) the reaction products trifluoroacetyl chloride and by-products sulfuryl chloride and pyrosulfuryl chloride in the steps 1) and 2) enter a stripping kettle along with part of raw materials of sulfur trioxide and trifluorotrichloroethane from a gas phase outlet of the oxo reaction kettle, and are stripped, condensed and separated at 64 ℃;
4) conveying trifluoroacetyl chloride separated from the stripping kettle to a hydrolysis absorption system from a top outlet, condensing and refluxing part of raw materials to an oxo reaction kettle, conveying sulfuryl chloride and pyrosulfuryl chloride to the bottom of a circulating distillation kettle, and placing the part of the liquid level in the circulating distillation kettle, which exceeds a lug, into a sulfuryl chloride intermediate tank;
the hydrolysis absorption system is a four-stage countercurrent hydrolysis absorption system and comprises a first absorption tower, a second absorption tower, a third absorption tower and a fourth absorption tower, wherein the bottom of the second absorption tower is connected with the top of the first absorption tower, the bottom of the third absorption tower is connected with the top of the second absorption tower, the bottom of the fourth absorption tower is connected with the top of the third absorption tower, an absorption liquid in the fourth absorption tower is tap water, the absorption liquid in the third absorption tower is a trifluoroacetic acid solution from the fourth absorption tower, and the concentration of the trifluoroacetic acid solution is controlled to be 35%; the absorption liquid in the second absorption tower is from the absorption liquid in the third absorption tower, and the concentration of the absorption liquid is controlled to be 76%; the absorption liquid in the first absorption tower is from the absorption liquid in the second absorption tower, and the concentration of the absorption liquid is controlled to be 87%;
the tail gas discharged from the top of the fourth absorption tower is mainly hydrogen chloride gas, and the hydrogen chloride gas is absorbed by water by adopting a falling film absorption method to prepare hydrochloric acid;
the hydrolysis absorption system works intermittently, the operation is stopped for 0.5 hour after the hydrolysis treatment is carried out for 2 hours, the operation is stopped for 0.5 hour after the hydrolysis treatment is continuously carried out for 2 hours, and the operation is repeated in a circulating way;
the method comprises the following steps that trifluoroacetyl chloride, sulfuryl chloride, pyrosulfuryl chloride and unreacted raw materials are separated from a stripping tower through primary water cooling and secondary freezing brine condensation, the freezing temperature of the secondary freezing brine is-20 ℃, the freezing time is 30min, poplar fibers and eucalyptus fibers are added into the secondary freezing brine, the total mass of the poplar fibers and the eucalyptus fibers accounts for 2% of the freezing brine, the ratio of the poplar fibers to the eucalyptus fibers is 3:6, and the beating degree of the poplar fibers and the eucalyptus fibers is 28SR degrees;
5) sulfuryl chloride, pyrosulfuryl chloride, trichlorotrifluoroethane and sulfur trioxide in the sulfuryl chloride intermediate tank are pumped into a circulating distillation kettle, rectification is carried out at the temperature of 50 ℃, and the rectified raw materials of sulfur trioxide and trichlorotrifluoroethane return to an oxo reaction kettle; sulfuryl chloride, pyrosulfuryl chloride and impurities in the sulfuryl chloride intermediate tank are cooled to normal temperature and then pumped into a sulfuryl chloride metering high-level tank to be hydrolyzed;
6) removing sulfur trioxide carried by trifluoroacetyl chloride gas through concentrated sulfuric acid, then, entering a water desorption system to obtain a trifluoroacetic acid crude product, and rectifying the trifluoroacetic acid crude product in a trifluoroacetic acid rectifying kettle under the conditions that the kettle bottom temperature is 85 ℃ and the kettle top temperature is 72 ℃ to obtain trifluoroacetic acid;
7) adding the trifluoroacetic acid obtained in the step 6) into an esterification kettle, taking concentrated sulfuric acid as a catalyst and a dehydrating agent, slowly dropwise adding ethanol, controlling the reaction temperature to be less than 50 ℃, wherein the mass ratio of the trifluoroacetic acid to the ethanol is 3:0.5, and the mass ratio of the trifluoroacetic acid to the concentrated sulfuric acid is 6: 0.06;
8) rectifying and condensing the ethyl trifluoroacetate obtained in the step 7) at the conditions of the kettle bottom temperature of 80 ℃ and the kettle top temperature of 62 ℃ to obtain a finished product of the ethyl trifluoroacetate;
9) hot water is conveyed to a sulfuryl chloride hydrolysis absorption system from a sulfuryl chloride metering high-level tank, byproduct disulfoyl chloride is dripped to the sulfuryl chloride hydrolysis absorption system from the sulfuryl chloride metering high-level tank, the sulfuryl chloride water desorption system is controlled to carry out hydrolysis reaction at 64 ℃, produced dilute sulfuric acid is collected into a sulfuric acid storage tank, hydrogen chloride gas generated in the hydrolysis process is absorbed by water through a falling film absorber, and obtained hydrochloric acid is collected into a hydrochloric acid storage tank.
The purity of the obtained ethyl trifluoroacetate finished product reaches more than 98.7 percent, and the yield is about 96 percent.
EXAMPLE III
1) 2.5kg of sulfur trioxide passes through an oxo reaction kettle from a storage tank through internal pressure, 2.5kg of trifluorotrichloroethane passes through the oxo reaction kettle, wherein the sulfur trioxide is heated by introducing hot water at about 70 ℃ into a jacket, the temperature in the oxo reaction kettle is controlled to be 61 ℃, and the reaction is carried out for 28 minutes;
2) 2kg of sulfur trioxide passes through an oxo reaction kettle from a storage tank through internal pressure, 4kg of trifluorotrichloroethane passes through the oxo reaction kettle, the temperature in the oxo reaction kettle is controlled to be 64 ℃, and the reaction lasts 25 minutes;
3) the reaction products trifluoroacetyl chloride and by-products sulfuryl chloride and pyrosulfuryl chloride in the steps 1) and 2) enter a stripping kettle along with part of raw materials of sulfur trioxide and trifluorotrichloroethane from a gas phase outlet of the oxo reaction kettle, and are stripped, condensed and separated at 64 ℃;
4) conveying trifluoroacetyl chloride separated from the stripping kettle to a hydrolysis absorption system from a top outlet, condensing and refluxing part of raw materials to an oxo reaction kettle, conveying sulfuryl chloride and pyrosulfuryl chloride to the bottom of a circulating distillation kettle, and placing the part of the liquid level in the circulating distillation kettle, which exceeds a lug, into a sulfuryl chloride intermediate tank;
the hydrolysis absorption system is a four-stage countercurrent hydrolysis absorption system and comprises a first absorption tower, a second absorption tower, a third absorption tower and a fourth absorption tower, wherein the bottom of the second absorption tower is connected with the top of the first absorption tower, the bottom of the third absorption tower is connected with the top of the second absorption tower, the bottom of the fourth absorption tower is connected with the top of the third absorption tower, an absorption liquid in the fourth absorption tower is tap water, the absorption liquid in the third absorption tower is a trifluoroacetic acid solution from the fourth absorption tower, and the concentration of the trifluoroacetic acid solution is controlled to be 40%; the absorption liquid in the second absorption tower is from the absorption liquid in the third absorption tower, and the concentration of the absorption liquid is controlled to be 78%; the absorption liquid in the first absorption tower is the absorption liquid from the second absorption tower, and the concentration of the absorption liquid is controlled to be 90 percent;
the tail gas discharged from the top of the fourth absorption tower is mainly hydrogen chloride gas, and the hydrogen chloride gas is absorbed by water by adopting a falling film absorption method to prepare hydrochloric acid;
the hydrolysis absorption system works intermittently, the operation is stopped for 0.5 hour after the hydrolysis treatment is carried out for 3 hours, the operation is stopped for 0.5 hour after the hydrolysis treatment is continuously carried out for 3 hours, and the operation is repeated in a circulating way;
the method comprises the following steps that trifluoroacetyl chloride, sulfuryl chloride, pyrosulfuryl chloride and unreacted raw materials are separated from a stripping tower through primary water cooling and secondary freezing brine condensation, the freezing temperature of the secondary freezing brine is-35 ℃, the freezing time is 35min, poplar fibers and eucalyptus fibers are added into the secondary freezing brine, the total mass of the poplar fibers and the eucalyptus fibers accounts for 3% of the freezing brine, the ratio of the poplar fibers to the eucalyptus fibers is 3:9, and the beating degree of the poplar fibers and the eucalyptus fibers is 29SR degrees;
5) sulfuryl chloride, pyrosulfuryl chloride, trichlorotrifluoroethane and sulfur trioxide in the sulfuryl chloride intermediate tank are pumped into a circulating distillation kettle, the circulating distillation kettle is controlled to be rectified at 52 ℃, and the rectified raw materials of sulfur trioxide and trichlorotrifluoroethane return to the oxo reaction kettle; sulfuryl chloride, pyrosulfuryl chloride and impurities in the sulfuryl chloride intermediate tank are cooled to normal temperature and then pumped into a sulfuryl chloride metering high-level tank to be hydrolyzed;
6) removing sulfur trioxide carried by trifluoroacetyl chloride gas through concentrated sulfuric acid, then, entering a water desorption system to obtain a trifluoroacetic acid crude product, and rectifying the trifluoroacetic acid crude product in a trifluoroacetic acid rectifying kettle under the conditions that the kettle bottom temperature is 85 ℃ and the kettle top temperature is 72 ℃ to obtain trifluoroacetic acid;
7) adding the trifluoroacetic acid obtained in the step 6) into an esterification kettle, taking concentrated sulfuric acid as a catalyst and a dehydrating agent, slowly dropwise adding ethanol, controlling the reaction temperature to be less than 50 ℃, wherein the mass ratio of the trifluoroacetic acid to the ethanol is 3:1.5, and the mass ratio of the trifluoroacetic acid to the concentrated sulfuric acid is 6: 0.04;
8) rectifying and condensing the ethyl trifluoroacetate obtained in the step 7) at the conditions of the kettle bottom temperature of 80 ℃ and the kettle top temperature of 62 ℃ to obtain a finished product of the ethyl trifluoroacetate;
9) hot water is conveyed to a sulfuryl chloride hydrolysis absorption system from a sulfuryl chloride metering high-level tank, byproduct disulfoyl chloride is dripped to the sulfuryl chloride hydrolysis absorption system from the sulfuryl chloride metering high-level tank, the sulfuryl chloride water desorption system is controlled to carry out hydrolysis reaction at 65 ℃, produced dilute sulfuric acid is collected into a sulfuric acid storage tank, hydrogen chloride gas generated in the hydrolysis process is absorbed by water through a falling film absorber, and obtained hydrochloric acid is collected into a hydrochloric acid storage tank.
The purity of the obtained ethyl trifluoroacetate finished product reaches more than 98.8 percent, and the yield is about 97.2 percent.
Example four
1) 3.2kg of sulfur trioxide passes through an oxo reaction kettle from a storage tank through internal pressure, 3.2kg of trifluorotrichloroethane passes through the oxo reaction kettle, wherein the sulfur trioxide is heated by introducing hot water at about 70 ℃ into a jacket, the temperature in the oxo reaction kettle is controlled to be 62 ℃, and the reaction is carried out for 30 minutes;
2) 2.5kg of sulfur trioxide passes through an oxo reaction kettle from a storage tank through internal pressure, 5kg of trifluorotrichloroethane passes through the oxo reaction kettle, the temperature in the oxo reaction kettle is controlled to be 65 ℃, and the reaction is carried out for 40 minutes;
3) the reaction products trifluoroacetyl chloride and by-products sulfuryl chloride and pyrosulfuryl chloride in the steps 1) and 2) enter a stripping kettle along with part of raw materials of sulfur trioxide and trifluorotrichloroethane from a gas phase outlet of the oxo reaction kettle, and are stripped, condensed and separated at the temperature of 65 ℃;
4) conveying trifluoroacetyl chloride separated from the stripping kettle to a hydrolysis absorption system from a top outlet, condensing and refluxing part of raw materials to an oxo reaction kettle, conveying sulfuryl chloride and pyrosulfuryl chloride to the bottom of a circulating distillation kettle, and placing the part of the liquid level in the circulating distillation kettle, which exceeds a lug, into a sulfuryl chloride intermediate tank;
the hydrolysis absorption system is a four-stage countercurrent hydrolysis absorption system and comprises a first absorption tower, a second absorption tower, a third absorption tower and a fourth absorption tower, wherein the bottom of the second absorption tower is connected with the top of the first absorption tower, the bottom of the third absorption tower is connected with the top of the second absorption tower, the bottom of the fourth absorption tower is connected with the top of the third absorption tower, an absorption liquid in the fourth absorption tower is tap water, the absorption liquid in the third absorption tower is a trifluoroacetic acid solution from the fourth absorption tower, and the concentration of the trifluoroacetic acid solution is controlled to be 38%; the absorption liquid in the second absorption tower is from the absorption liquid in the third absorption tower, and the concentration of the absorption liquid is controlled to be 80 percent; the absorption liquid in the first absorption tower is from the absorption liquid in the second absorption tower, and the concentration of the absorption liquid is controlled to be 95 percent;
the tail gas discharged from the top of the fourth absorption tower is mainly hydrogen chloride gas, and the hydrogen chloride gas is absorbed by water by adopting a falling film absorption method to prepare hydrochloric acid;
the hydrolysis absorption system works intermittently, the operation is stopped for 0.5 hour after the hydrolysis treatment is carried out for 2.8 hours, the operation is stopped for 0.5 hour after the hydrolysis treatment is continuously carried out for 2.8 hours, and the operation is repeated in a circulating way;
the method comprises the following steps that trifluoroacetyl chloride, sulfuryl chloride, pyrosulfuryl chloride and unreacted raw materials are separated from a stripping tower through primary water cooling and secondary freezing brine condensation, the freezing temperature of the secondary freezing brine is-45 ℃, the freezing time is 35min, poplar fibers and eucalyptus fibers are added into the secondary freezing brine, the total mass of the poplar fibers and the eucalyptus fibers accounts for 3% of the freezing brine, the ratio of the poplar fibers to the eucalyptus fibers is 3:10, and the beating degree of the poplar fibers and the eucalyptus fibers is 30SR degrees;
5) sulfuryl chloride, pyrosulfuryl chloride, trichlorotrifluoroethane and sulfur trioxide in the sulfuryl chloride intermediate tank are pumped into a circulating distillation kettle, the circulating distillation kettle is controlled to be rectified at 52 ℃, and the rectified raw materials of sulfur trioxide and trichlorotrifluoroethane return to the oxo reaction kettle; sulfuryl chloride, pyrosulfuryl chloride and impurities in the sulfuryl chloride intermediate tank are cooled to normal temperature and then pumped into a sulfuryl chloride metering high-level tank to be hydrolyzed;
6) removing sulfur trioxide carried by trifluoroacetyl chloride gas through concentrated sulfuric acid, then, entering a water desorption system to obtain a trifluoroacetic acid crude product, and rectifying the trifluoroacetic acid crude product in a trifluoroacetic acid rectifying kettle under the conditions that the kettle bottom temperature is 85 ℃ and the kettle top temperature is 72 ℃ to obtain trifluoroacetic acid;
7) adding the trifluoroacetic acid obtained in the step 6) into an esterification kettle, taking concentrated sulfuric acid as a catalyst and a dehydrating agent, slowly dropwise adding ethanol, controlling the reaction temperature to be less than 50 ℃, wherein the mass ratio of the trifluoroacetic acid to the ethanol is 3:1.6, and the mass ratio of the trifluoroacetic acid to the concentrated sulfuric acid is 6: 0.07;
8) rectifying and condensing the ethyl trifluoroacetate obtained in the step 7) at the conditions of the kettle bottom temperature of 80 ℃ and the kettle top temperature of 62 ℃ to obtain a finished product of the ethyl trifluoroacetate;
9) hot water is conveyed to a sulfuryl chloride hydrolysis absorption system from a sulfuryl chloride metering high-level tank, byproduct disulfoyl chloride is dripped to the sulfuryl chloride hydrolysis absorption system from the sulfuryl chloride metering high-level tank, the sulfuryl chloride water desorption system is controlled to carry out hydrolysis reaction at 66 ℃, produced dilute sulfuric acid is collected into a sulfuric acid storage tank, hydrogen chloride gas generated in the hydrolysis process is absorbed by water through a falling film absorber, and obtained hydrochloric acid is collected into a hydrochloric acid storage tank.
The purity of the obtained ethyl trifluoroacetate finished product reaches more than 97.9 percent, and the yield is about 96 percent.
The foregoing detailed description is intended to illustrate and not limit the invention, which is intended to be within the spirit and scope of the appended claims, and any changes and modifications that fall within the true spirit and scope of the invention are intended to be covered by the following claims.
Claims (5)
1. A preparation method of ethyl trifluoroacetate is characterized by comprising the following steps:
1) introducing sulfur trioxide and trifluorotrichloroethane in a mass ratio of 1:1 into an oxo reaction kettle, controlling the temperature of the oxo reaction kettle to be 58-62 ℃, and reacting for 20-30 min;
2) introducing sulfur trioxide and trifluorotrichloroethane in a mass ratio of 1:2 into an oxo reaction kettle, controlling the temperature of the oxo reaction kettle to be 60-65 ℃, and reacting for 10-40 min;
3) the reaction products trifluoroacetyl chloride and by-products sulfuryl chloride and pyrosulfuryl chloride in the steps 1) and 2) enter a stripping kettle along with part of raw materials of sulfur trioxide and trifluorotrichloroethane from a gas phase outlet of the oxo reaction kettle, and are subjected to stripping condensation separation at the temperature of 63-65 ℃;
4) conveying trifluoroacetyl chloride separated from the stripping kettle to a hydrolysis absorption system from a top outlet, condensing and refluxing part of raw materials to an oxo reaction kettle, conveying sulfuryl chloride and pyrosulfuryl chloride to the bottom of a circulating distillation kettle, and placing the part of the liquid level in the circulating distillation kettle, which exceeds a lug, into a sulfuryl chloride intermediate tank; the stripping kettle is used for separating trifluoroacetyl chloride, sulfuryl chloride, pyrosulfuryl chloride and unreacted raw materials through primary water cooling and secondary freezing brine condensation; the secondary frozen saline is added with poplar fiber and eucalyptus fiber, and the total mass of the secondary frozen saline accounts for 2-4% of that of the frozen saline;
5) sulfuryl chloride, pyrosulfuryl chloride, trichlorotrifluoroethane and sulfur trioxide in the sulfuryl chloride intermediate tank are pumped into a circulating distillation kettle, the circulating distillation kettle is controlled to be rectified at 48-52 ℃, and the rectified raw materials of sulfur trioxide and trichlorotrifluoroethane return to the oxo reaction kettle; sulfuryl chloride, pyrosulfuryl chloride and impurities in the sulfuryl chloride intermediate tank are cooled to normal temperature and then pumped into a sulfuryl chloride metering high-level tank to be hydrolyzed;
6) removing sulfur trioxide carried by trifluoroacetyl chloride gas through concentrated sulfuric acid, then, entering a water desorption system to obtain a crude product of trifluoroacetic acid, and rectifying the crude product of trifluoroacetic acid in a trifluoroacetic acid rectifying kettle at the kettle bottom temperature of 75-90 ℃ and the kettle top temperature of 68-74 ℃ to obtain trifluoroacetic acid;
7) adding the trifluoroacetic acid obtained in the step 6) into an esterification kettle, taking concentrated sulfuric acid as a catalyst and a dehydrating agent, slowly dropwise adding ethanol, controlling the reaction temperature to be less than 50 ℃, wherein the mass ratio of the trifluoroacetic acid to the ethanol is 3:0.3-1.6, and the mass ratio of the trifluoroacetic acid to the concentrated sulfuric acid is 6: 0.02-0.07;
8) rectifying and condensing the ethyl trifluoroacetate obtained in the step 7) at the conditions of the kettle bottom temperature of 65-90 ℃ and the kettle top temperature of 60-66 ℃ to obtain a finished product of the ethyl trifluoroacetate;
9) hot water is conveyed to a sulfuryl chloride hydrolysis absorption system from a sulfuryl chloride metering high-level tank, by-products sulfuryl chloride, pyrosulfuryl chloride and impurities are dropwise added to the sulfuryl chloride hydrolysis absorption system from the sulfuryl chloride metering high-level tank, the sulfuryl chloride hydrolysis absorption system is controlled to carry out hydrolysis reaction at 63-66 ℃, produced dilute sulfuric acid is collected into a sulfuric acid storage tank, hydrogen chloride gas generated in the hydrolysis process is absorbed by water through a falling film absorber, and obtained hydrochloric acid is collected into a hydrochloric acid storage tank.
2. The process for the preparation of ethyl trifluoroacetate according to claim 1, characterized in that: the trifluoroacetyl chloride water desorption and absorption system is a four-stage countercurrent hydrolysis and absorption system and comprises a first absorption tower, a second absorption tower, a third absorption tower and a fourth absorption tower, wherein the bottom of the second absorption tower is connected with the top of the first absorption tower, absorption liquid in the fourth absorption tower is tap water, the absorption liquid in the third absorption tower is absorption liquid from the fourth absorption tower, and the concentration of the absorption liquid is controlled to be 30-40%; the absorption liquid in the second absorption tower is from the absorption liquid in the third absorption tower, and the concentration of the absorption liquid is controlled to be 70-80%; the absorption liquid in the first absorption tower is from the absorption liquid in the second absorption tower, and the concentration of the absorption liquid is controlled to be 85-95%.
3. The process for the preparation of ethyl trifluoroacetate according to claim 2, characterized in that: the hydrolysis absorption system works intermittently, the hydrolysis treatment is carried out for 1.5 to 3 hours, then the hydrolysis treatment is kept for 0.5 hour, and the circulation operation is continued.
4. The process for the preparation of ethyl trifluoroacetate according to claim 1, characterized in that: the freezing temperature of the secondary frozen brine is-5 to-45 ℃, and the freezing time is 20 to 40 min.
5. The process for the preparation of ethyl trifluoroacetate according to claim 1, characterized in that: the ratio of the poplar fiber to the eucalyptus fiber is 3:6-10, and the beating degrees of the poplar fiber and the eucalyptus fiber are both 25-30 DEG SR.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4382897A (en) * | 1981-07-23 | 1983-05-10 | Kali Chemie Ag | Process for the preparation of trifluoracetic acid derivatives |
| JPS60237040A (en) * | 1984-05-09 | 1985-11-25 | Daikin Ind Ltd | Preparation of perhalogenoalkanoic acid chloride |
| US4879407A (en) * | 1986-10-16 | 1989-11-07 | Rhone-Poulenc Chimie | Process for the preparation of ethyl trifluoroacetate |
| US4916256A (en) * | 1985-07-19 | 1990-04-10 | Ausimont, S.P.A. | Process for the production of alkyl trifluoroacetates |
| US5405991A (en) * | 1993-04-27 | 1995-04-11 | Solvay Fluor & Derivate | Process for producing carboxylic acid esters from carboxylic acid halides and alcohols |
| CN1281847A (en) * | 1999-07-21 | 2001-01-31 | 罗姆和哈斯公司 | Process for preparation of trifluoroacetate and trifluoroacetic thioester |
| CN102276463A (en) * | 2011-08-01 | 2011-12-14 | 海门瑞一医药科技有限公司 | Process for producing ethyl trifluoroacetate |
| CN102351681A (en) * | 2011-08-16 | 2012-02-15 | 浙江大学 | Method for continuously synthesizing trifluoroacetyl chloride and sulfuryl fluoride |
| CN102351694A (en) * | 2011-10-17 | 2012-02-15 | 三明市海斯福化工有限责任公司 | Preparation method of trifluoroacetic acid ethyl ester |
| CN102531896A (en) * | 2011-12-26 | 2012-07-04 | 田晓琴 | Production method of ethyl trifluoroacetate |
| CN103864615A (en) * | 2012-12-07 | 2014-06-18 | 中化蓝天集团有限公司 | Method for preparing ethyl trifluoroacetate through continuous non-catalytic method |
| CN106431908A (en) * | 2016-09-19 | 2017-02-22 | 南通宝凯化工有限公司 | Ethyl trifluoroacetate preparation method |
-
2018
- 2018-11-12 CN CN201811337714.6A patent/CN109369385B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4382897A (en) * | 1981-07-23 | 1983-05-10 | Kali Chemie Ag | Process for the preparation of trifluoracetic acid derivatives |
| JPS60237040A (en) * | 1984-05-09 | 1985-11-25 | Daikin Ind Ltd | Preparation of perhalogenoalkanoic acid chloride |
| US4916256A (en) * | 1985-07-19 | 1990-04-10 | Ausimont, S.P.A. | Process for the production of alkyl trifluoroacetates |
| US4879407A (en) * | 1986-10-16 | 1989-11-07 | Rhone-Poulenc Chimie | Process for the preparation of ethyl trifluoroacetate |
| US5405991A (en) * | 1993-04-27 | 1995-04-11 | Solvay Fluor & Derivate | Process for producing carboxylic acid esters from carboxylic acid halides and alcohols |
| CN1281847A (en) * | 1999-07-21 | 2001-01-31 | 罗姆和哈斯公司 | Process for preparation of trifluoroacetate and trifluoroacetic thioester |
| CN102276463A (en) * | 2011-08-01 | 2011-12-14 | 海门瑞一医药科技有限公司 | Process for producing ethyl trifluoroacetate |
| CN102351681A (en) * | 2011-08-16 | 2012-02-15 | 浙江大学 | Method for continuously synthesizing trifluoroacetyl chloride and sulfuryl fluoride |
| CN102351694A (en) * | 2011-10-17 | 2012-02-15 | 三明市海斯福化工有限责任公司 | Preparation method of trifluoroacetic acid ethyl ester |
| CN102531896A (en) * | 2011-12-26 | 2012-07-04 | 田晓琴 | Production method of ethyl trifluoroacetate |
| CN103864615A (en) * | 2012-12-07 | 2014-06-18 | 中化蓝天集团有限公司 | Method for preparing ethyl trifluoroacetate through continuous non-catalytic method |
| CN106431908A (en) * | 2016-09-19 | 2017-02-22 | 南通宝凯化工有限公司 | Ethyl trifluoroacetate preparation method |
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