Background technology
Fluoroform sulfonic acid fluoride is the important intermediate of field of fine chemical, can as important source material such as organic synthesis, agricultural chemicals medicine, ionic liquid and lithium-ion electrolytes.Under fluoroform sulfonic acid fluoride normal pressure, boiling point is-21.7 DEG C, and be have faint odor under normal temperature, liquescent gas, does not react with hydrogen, is insoluble to cold water, hydrogen fluoride etc., facile hydrolysis under hot water and alkaline condition.
In prior art, the method preparing fluoroform sulfonic acid fluoride has photodissociation method, chemical direct fluorination, electrolytic process and fluoridizes the method for trifluoromethanesulfchloride chloride with Potassium monofluoride, current industrial most widely used be electrolytic process.Described electrolytic process is with methanesulfonyl fluoride (CH
3sO
2or Methanesulfonyl chloride (CH F)
3sO
2cl) be raw material, and excessive liquid-fluorination hydrogen (HF) carries out electrochemical fluorination reaction in a cell, produce the method for fluoroform sulfonic acid fluoride.The electrolysate of described electrolytic process is gaseous mixture, main containing fluoroform sulfonic acid fluoride, hydrogen (H
2), tetrafluoro-methane (CF
4), difluoro sulfoxide (SOF
2), carbonic acid gas (CO
2) and oxygen difluoride (OF
2); Because hydrogen fluoride is excessive, and its saturated vapor pressure is higher, makes also to be mingled with a certain amount of hydrogen fluoride gas in described electrolysate.In described electrolysate, except hydrogen, all the other foreign gas content are not high, but affect the use of fluoroform sulfonic acid fluoride, therefore must purify to electrolysate described in it.
At present, less for the purification process of fluoroform sulfonic acid fluoride in the electrolysate of electrolytic process, non-patent literature 1 (model spring thunder, Liu Changyuan. the study on the synthesis [J] of Trifluoromethanesulfonic anhydride. organic fluorine industry, 2005 (4): 6.) report electrolysate is drawn from electrolyzer outlet, make wherein to be returned to electrolyzer by the hydrogen fluoride cooling for reflux carried under one's arms out through condenser, remaining gas enters water resorber through snubber and alkali cleaning resorber removes whole hydrogenchloride and hydrogen fluoride, gas-holder is entered again through a gas-liquid separator, gas passes through mole sieve drier after being introduced into lyophilization device by hydrogen gas compressor extraction, to remove washing and the moisture content brought into of alkaline cleaning procedure, dried gas flows into trifluoromethane sulfonic acid fluoride storage tank through cryogenic liquefying, be not condensed the hydrogen gas automatic blow down liquefied.
The method of the fluoroform sulfonic acid fluoride separation and purification that patent documentation 1 (Chinese patent CN200810243626.X) is reported comprises following content: methanesulfonyl fluoride electrochemical fluorination gas-phase product is carried out cooling condensation, hydrogen fluoride is wherein made to be condensed into liquid phase, afterwards after gas-liquid separation, by gaseous phase materials by carbonate aqueous solution water absorption removing hydrogen fluoride, again through gas-liquid separation, then gaseous phase materials is added dewatering agent, dehydrate, again after gas solid separation, gaseous phase materials is carried out deep cooling, finally it is carried out to gas-liquid separation is refining obtains product fluoroform sulfonic acid fluoride gas.
In described non-patent literature 1 and patent documentation 1, all following steps are comprised to the purification process of fluoroform sulfonic acid fluoride in the electrolysate of electrolysis methanesulfonyl fluoride or Methanesulfonyl chloride: condensation remove portion hydrogen fluoride, most of hydrogen fluoride is removed in carbonate water eccysis, dewatering agent is used to remove the moisture brought in fluorinated hydrogen process, comparatively pure fluoroform sulfonic acid fluoride is obtained again through deep cooling removing hydrogen, this kind of purification process has following problem: (1) purification step is many, the equipment needed is also more, need to walk the gas-liquid separation equipment of multistep, water removal device; (2) safety issue of technique, because the operational path adopted is longer, and hydrogen in the end a step just removes, the leakage explosion hazard of easy generation hydrogen, therefore higher to the sealing requirements of all purifier apparatus; (3) fluoroform sulfonic acid fluoride can be hydrolyzed in basic solution, carbonate solution is used to absorb removing hydrogen fluoride, meeting simultaneously stability part fluoroform sulfonic acid fluoride, cause the loss of purified product, fluoroform sulfonic acid fluoride and carbonate reaction can produce carbonic acid gas simultaneously, bring new impurity, affect the purity of purified product; (4) take first to introduce moisture, then through the method that dewatering agent dewaters, activation dewatering agent needs to consume rare gas element and electric energy, and the energy consumption of purifying is increased; (5) purified product finally just obtains through simple gas-liquid separation removing hydrogen, and light constituent impurity is as tetrafluoro-methane (CF
4), difluoro sulfoxide (SOF
2), carbonic acid gas (CO
2) and oxygen difluoride (OF
2) not through effective measure removing, the final purity of purified product fluoroform sulfonic acid fluoride is not all mentioned in described document.
Summary of the invention
For overcoming the defect that prior art exists, the object of the present invention is to provide a kind of purification process of fluoroform sulfonic acid fluoride, the fluoroform sulfonic acid fluoride purity obtained after described method purifying is improved, the purifier apparatus adopted is less, purifying flow process is simplified, and the security of production process effectively improves.
For realizing object of the present invention, provide following technical scheme.
A purification process for fluoroform sulfonic acid fluoride, the raw material to be purified of described purification process is the electrolysate preparing fluoroform sulfonic acid fluoride with electrolytic process; Described electrolytic process is with methanesulfonyl fluoride or Methanesulfonyl chloride for raw material, and excessive hydrogen fluoride carries out the method that fluoroform sulfonic acid fluoride is produced in electrochemical fluorination reaction in a cell; Described electrolysate is gaseous mixture, main containing fluoroform sulfonic acid fluoride, light constituent impurity: hydrogen, tetrafluoro-methane, difluoro sulfoxide, carbonic acid gas and oxygen difluoride, and heavy constituent impurity hydrogen fluoride gas; In the cumulative volume of described raw material to be purified for 100%, wherein, volume content >=15% of fluoroform sulfonic acid fluoride, hydrofluoric volume content≤2%, volume content≤80% of hydrogen, volume content≤1% of tetrafluoro-methane, volume content≤1% of difluoro sulfoxide, volume content≤0.4% of carbonic acid gas, volume content≤0.5% of oxygen difluoride;
Described purification process step is as follows:
Rectification and purification is carried out in rectifying still raw material to be purified being passed into rectifying tower, control rectifying condition as follows: rectifying still temperature is-15 DEG C ~ 40 DEG C, rectifying column temperature is-80 DEG C ~-20 DEG C, rectifying still pressure is 0MPa ~ 2.5MPa, preferred rectifying condition is as follows: rectifying still temperature is-10 DEG C ~ 20 DEG C, rectifying column temperature is-50 DEG C ~-20 DEG C, rectifying still pressure is 1.1MPa ~ 2.0MPa, make in rectifying fluoroform sulfonic acid fluoride seethe with excitement and at rectifying column internal reflux, mixed gas, at rectifying column apical enrichment, detects the volume content of each gaseous fraction in mixed gas:
When volume content≤0.1% of fluoroform sulfonic acid fluoride in mixed gas, the reflux ratio controlling fluoroform sulfonic acid fluoride in rectifying column is 31 ~ 45, is discharged by the mixed gas of rectifying column apical enrichment as waste gas;
As the volume content > 0.1% of fluoroform sulfonic acid fluoride in mixed gas, but when gas component volumes content does not reach index request, the reflux ratio controlling fluoroform sulfonic acid fluoride in rectifying column is 20 ~ 30, the mixed gas of rectifying column apical enrichment is discharged and is collected in crude product tank, can be used as raw material to be purified and recycle;
When in mixed gas, gas component volumes content reaches requirement index, the reflux ratio controlling fluoroform sulfonic acid fluoride in rectifying column is 9 ~ 15, is collected in fine work tank by the mixed gas of rectifying column apical enrichment, obtains the fluoroform sulfonic acid fluoride after purifying;
When volume content hydrofluoric in mixed gas is discontented with sufficient index request, stop the mixed gas collecting rectifying column apical enrichment, can discharge together with gas more with rectifying still bottom fluorochemical hydrogen for described mixed gas, provide hydrogen fluoride to recycle to electrolyzer;
Wherein, described index request is as follows: volume content >=99.5% of fluoroform sulfonic acid fluoride, moisture volume content≤0.01%, hydrofluoric volume content≤0.3%, volume content≤0.01% of tetrafluoro-methane, volume content≤0.01% of difluoro sulfoxide, volume content≤0.01% of carbonic acid gas, volume content≤0.01% of oxygen difluoride.
Described rectifying tower is primarily of rectifying still and rectifying column composition, rectifying column is fixedly connected on above rectifying still, and be communicated with rectifying still, its mode of operation is batch fractionating, rectifying column internal diameter is 25mm ~ 100mm, be highly 800mm ~ 2500mm, rectifying column is the θ ring filler of 2mm ~ 8mm built with diameter; Rectifying tower is communicated with fine work tank with vacuum pump, crude product tank by pipeline, and above rectifying column top, pipeline is provided with under meter.
The material of described rectifying tower, filler, pipeline, crude product tank and fine work tank can be in stainless steel, nickel, Hastelloy or Monel metal more than one.
Beneficial effect
1. the invention provides a kind of purification process of fluoroform sulfonic acid fluoride, described purification process not only can remove the light constituent impurity in raw material to be purified by a step rectifying, and heavy constituent impurity can be controlled, obtain the fluoroform sulfonic acid fluoride of purity >=99.5%, equipment required for described method is few, simple to operate, process safety;
2. the invention provides a kind of purification process of fluoroform sulfonic acid fluoride, in described purification process when volume content≤0.1% of fluoroform sulfonic acid fluoride in mixed gas, due in now mixed gas containing most of hydrogen, a small amount of tetrafluoro-methane and oxygen difluoride, therefore the energy consumption reclaiming fluoroform sulfonic acid fluoride is large, production cost is higher, therefore, this part mixed gas is discharged as waste gas; As the volume content > 0.1% of fluoroform sulfonic acid fluoride in mixed gas, but when each gas component volumes content does not reach index request, mixed gas is discharged and is collected in crude product tank, can be used as raw material to be purified and recycle, fully reclaim fluoroform sulfonic acid fluoride; When volume content hydrofluoric in mixed gas is discontented with sufficient index request, can discharges together with gas more with rectifying still bottom fluorochemical hydrogen for mixed gas, provide hydrogen fluoride to recycle to electrolyzer.
Embodiment
In order to absolutely prove characteristic of the present invention and implement mode of the present invention, provide embodiment below.
In following examples:
Rectifier unit used as shown in Figure 1, forms primarily of rectifying still tower, rectifying column 2, vacuum pump 3, under meter 4, crude product tank 5 and fine work tank 6, and the mode of operation of described rectifying tower is batch fractionating, forms primarily of rectifying still 1 and rectifying column 2, wherein, raw material to be purified enters rectifying still 1 by the valve V1 on the pipeline that is communicated with rectifying still 1, rectifying column 2 is fixed on above rectifying still 1 and is also directly communicated with rectifying still 1, above rectifying column 2 top, pipeline is provided with under meter 4, under meter 4 rear pipeline is divided into 3 branch roads, Article 1, branch road connects vacuum pump 3 by valve V2, mixed gas when Article 2 branch road discharges volume content≤0.1% of fluoroform sulfonic acid fluoride by pipeline after valve V3, Article 3 branch road is divided into two branch roads by obtaining pipeline after valve V4, article one, branch road is communicated with crude product tank 5, another branch road is communicated with fine work tank 6.
Used detection method is in table 1.
Detection method in table 1 embodiment
Test item |
Detection method |
Hydrogen fluoride |
Fluoride ion electrode method |
Water |
Phosphorus pentoxide electrolysis method |
Gaseous fraction |
Vapor-phase chromatography |
Note: in table 1, gaseous fraction is fluoroform sulfonic acid fluoride, hydrogen, tetrafluoro-methane, difluoro sulfoxide, carbonic acid gas and oxygen difluoride.
The volume content of nitrogen used is 99.999%.
Described index request is as follows: volume content >=99.5% of fluoroform sulfonic acid fluoride, moisture volume content≤0.01%, hydrofluoric volume content≤0.3%, volume content≤0.01% of tetrafluoro-methane, volume content≤0.01% of difluoro sulfoxide, volume content≤0.01% of carbonic acid gas, volume content≤0.01% of oxygen difluoride.
After bed blending purifying to be purified in mixed gas, each gaseous fraction and volume content thereof are in table 2.
Embodiment 1
In the present embodiment rectifier unit used, the loading height of rectifying still 1 is 650mm, and volume is 50L, the internal diameter of rectifying column 2 is 25mm, be highly the diameter of 800mm, θ ring filler be 2mm, the material of rectifying still, rectifying column, filler, pipeline, crude product tank and fine work tank is stainless steel.Described rectifier unit first deoils before use, dries, finds time, and with nitrogen replacement 3 times.
A purification process for fluoroform sulfonic acid fluoride, described purification process step is as follows:
Raw material to be purified for 10kg is passed in rectifying still, control rectifying still temperature and be-15 DEG C, rectifying column temperature is-80 DEG C, rectifying still pressure is 0MPa, make in rectifying fluoroform sulfonic acid fluoride seethe with excitement and at rectifying column internal reflux, mixed gas, at rectifying column apical enrichment, detects the volume content of each gaseous fraction in mixed gas:
When volume content≤0.1% of fluoroform sulfonic acid fluoride in mixed gas, the reflux ratio controlling fluoroform sulfonic acid fluoride in rectifying column is 31, is discharged by the mixed gas of rectifying column apical enrichment as waste gas;
As the volume content > 0.1% of fluoroform sulfonic acid fluoride in mixed gas, but when gas component volumes content does not reach index request, the reflux ratio controlling fluoroform sulfonic acid fluoride in rectifying column is 20, the mixed gas of rectifying column apical enrichment is discharged and is collected in crude product tank, can be used as raw material to be purified and recycle;
When in mixed gas, gas component volumes content reaches requirement index, the reflux ratio controlling fluoroform sulfonic acid fluoride in rectifying column is 9, is collected in by the mixed gas of rectifying column apical enrichment in fine work tank;
When volume content hydrofluoric in mixed gas is discontented with sufficient index request, stop the mixed gas collecting rectifying column apical enrichment, can discharge together with gas more with rectifying still bottom fluorochemical hydrogen for described mixed gas, provide hydrogen fluoride to recycle to electrolyzer;
After purifying completes, be collected in the gas mixture body weight 7.85kg in fine work tank, yield is 78.5%.
Embodiment 2
In the present embodiment rectifier unit used, the loading height of rectifying still 1 is 2300mm, and volume is 500L, the internal diameter of rectifying column 2 is 100mm, be highly the diameter of 2500mm, θ ring filler be 8mm, the material of rectifying still, rectifying column, filler, pipeline, crude product tank and fine work tank is stainless steel.Described rectifier unit first deoils before use, dries, finds time, and with nitrogen replacement 5 times.
A purification process for fluoroform sulfonic acid fluoride, described purification process step is as follows:
Raw material to be purified for 200kg is passed in rectifying still, controlling rectifying still temperature is 40 DEG C, rectifying column temperature is-20 DEG C, rectifying still pressure is 2.5MPa, make in rectifying fluoroform sulfonic acid fluoride seethe with excitement and at rectifying column internal reflux, mixed gas, at rectifying column apical enrichment, detects the volume content of each gaseous fraction in mixed gas:
When volume content≤0.1% of fluoroform sulfonic acid fluoride in mixed gas, the reflux ratio controlling fluoroform sulfonic acid fluoride in rectifying column is 45, is discharged by the mixed gas of rectifying column apical enrichment as waste gas;
As the volume content > 0.1% of fluoroform sulfonic acid fluoride in mixed gas, but when gas component volumes content does not reach index request, the reflux ratio controlling fluoroform sulfonic acid fluoride in rectifying column is 30, the mixed gas of rectifying column apical enrichment is discharged and is collected in crude product tank, can be used as raw material to be purified and recycle;
When in mixed gas, gas component volumes content reaches requirement index, the reflux ratio controlling fluoroform sulfonic acid fluoride in rectifying column is 15, is collected in by the mixed gas of rectifying column apical enrichment in fine work tank;
When volume content hydrofluoric in mixed gas is discontented with sufficient index request, stop the mixed gas collecting rectifying column apical enrichment, can discharge together with gas more with rectifying still bottom fluorochemical hydrogen for described mixed gas, provide hydrogen fluoride to recycle to electrolyzer;
After purifying completes, be collected in the gas mixture body weight 158.30kg in fine work tank, yield is 79.15%.
Embodiment 3
In the present embodiment rectifier unit used, the loading height of rectifying still 1 is 1300mm, and volume is 300L, the internal diameter of rectifying column 2 is 100mm, be highly the diameter of 1500mm, θ ring filler be 5mm, the material of rectifying still, rectifying column, filler, pipeline, crude product tank and fine work tank is stainless steel.Described rectifier unit first deoils before use, dries, finds time, and with nitrogen replacement 4 times.
A purification process for fluoroform sulfonic acid fluoride, described purification process step is as follows:
Raw material to be purified for 100kg is passed in rectifying still, controlling rectifying still temperature is 10 DEG C, rectifying column temperature is-60 DEG C, rectifying still pressure is 1.2MPa, make in rectifying fluoroform sulfonic acid fluoride seethe with excitement and at rectifying column internal reflux, mixed gas, at rectifying column apical enrichment, detects the volume content of each gaseous fraction in mixed gas:
When volume content≤0.1% of fluoroform sulfonic acid fluoride in mixed gas, the reflux ratio controlling fluoroform sulfonic acid fluoride in rectifying column is 38, is discharged by the mixed gas of rectifying column apical enrichment as waste gas;
As the volume content > 0.1% of fluoroform sulfonic acid fluoride in mixed gas, but when gas component volumes content does not reach index request, the reflux ratio controlling fluoroform sulfonic acid fluoride in rectifying column is 26, the mixed gas of rectifying column apical enrichment is discharged and is collected in crude product tank, can be used as raw material to be purified and recycle;
When in mixed gas, gas component volumes content reaches requirement index, the reflux ratio controlling fluoroform sulfonic acid fluoride in rectifying column is 12, is collected in by the mixed gas of rectifying column apical enrichment in fine work tank;
When volume content hydrofluoric in mixed gas is discontented with sufficient index request, stop the mixed gas collecting rectifying column apical enrichment, can discharge together with gas more with rectifying still bottom fluorochemical hydrogen for described mixed gas, provide hydrogen fluoride to recycle to electrolyzer;
After purifying completes, be collected in the gas mixture body weight 80.35kg in fine work tank, yield is 80.35%.
Each gaseous fraction and volume content thereof in mixed gas after raw material to be purified and purifying in table 2 embodiment
The present invention includes but be not limited to above embodiment, every any equivalent replacement of carrying out under the principle of spirit of the present invention or local improvement, all will be considered as within protection scope of the present invention.