CA1196345A - Process for the preparation of very pure partially fluorinated ethanes - Google Patents
Process for the preparation of very pure partially fluorinated ethanesInfo
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- CA1196345A CA1196345A CA000372965A CA372965A CA1196345A CA 1196345 A CA1196345 A CA 1196345A CA 000372965 A CA000372965 A CA 000372965A CA 372965 A CA372965 A CA 372965A CA 1196345 A CA1196345 A CA 1196345A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
- B01J27/06—Halogens; Compounds thereof
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/07—Preparation of halogenated hydrocarbons by addition of hydrogen halides
- C07C17/087—Preparation of halogenated hydrocarbons by addition of hydrogen halides to unsaturated halogenated hydrocarbons
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Abstract
Abstract:
Process for the preparation of very pure partially fluorinated ethanes The reaction of fluorine-containing ethylenes of the formula CF2=CXY, in which X denotes H or F and Y denotes H, F, C1, Br or iodine, with hydrogen fluoride to form fluorine-containing ethanes of the formula CF3-CHXY is carried out, according to the invention, at temperatures of 20 - 200°C and in the presence of a chromium oxyfluoride catalyst which has been treated with hydrogen fluoride. Only a small amount of by-products is formed in this process.
Process for the preparation of very pure partially fluorinated ethanes The reaction of fluorine-containing ethylenes of the formula CF2=CXY, in which X denotes H or F and Y denotes H, F, C1, Br or iodine, with hydrogen fluoride to form fluorine-containing ethanes of the formula CF3-CHXY is carried out, according to the invention, at temperatures of 20 - 200°C and in the presence of a chromium oxyfluoride catalyst which has been treated with hydrogen fluoride. Only a small amount of by-products is formed in this process.
Description
The present invention relates to a process for the preparation of very pure partially fluorinated ethanes by the hydro~luorination of fluorine-con-tair~ng ethylenes.
Because of ~heir particular chemical and phvsical properties, partially fluorinated ethanes of the general formula , CF3-CHXY
in whi~-h X denotes H or F and Y denotes H, F~ r or I, are suitable for use in nwmerous fields of applica tion, ~or ex~mple as additi~res in gaseous analgesics and ~esthetics~ as heat exchan~e media or as componeIlts of propellanis, Simple and economical proces~es ior the preparation o representatives of this cizss of cQ~pcunds are therefore of interest.
The said partially fluorinated ethanes ~e in ~hemselve~ known and can be prepared by several, gene.ally laboratory-scale, processes. If ~rery pure fluorine-containing ethylenes of th~ general formula CF2=CXY are available in sufficient a~ourlt, hydrofluorination in the gas phase, in the presence of a solid caialyst, is a possible method~
~ he addition of hydrogen fluoride onto fluorine-containing ethylenes, in the gas phase, with the forma-tion of partially fluorinated ethanes in accordance withthe equation ~X X
~C=C ~ f HF ~ F3 CH
63~S
has alr~ady been described for some compounds However, all known fluorination processes in the gas phase require relatively high temperatures~ ge~erally above 250C and in some cases even above 400C. At these temperatures, 5 undesired side reactions necessarily result. For example, in the case of ethylenes which contain chlorine, bromine or iodine atoms, the halogen can be substituted by fluorine. Even in the partially fluorinated athane formed, the halogen ca~ be dis~laced by the fluorine of the hydroge~ fluoride at the high temperatures mentioned.
This reacti~rity ca~ be used diractly for the ~r~paration of F-substituted co~pounds. For exa~ple, aocording to U.S Patent ~pecification 2,951,102, the compound ÇF3CHClF is prepared from CF2BrCHClF by react on wich HF, at 300C, cn a chromium oxyfluoride catalyst.
The hydrofluorination of trifluGroethylQne at reaction temperatures of 350C is described in Germarl ~ffenlegungsschrift 2,837,515 This proce s uses a chromium oxyfluoride catalyst which was prepared accord-ing to British Pa-tent ~pecification 1,307,2~4. The yields of 1,1,1,2-tetrafluorGethane are 90 to 95% o~
theory. The possible residence 'imes lie within narrow limits and the proportion of fluorinated by-products is high Again on a chromium oxyfluoride catalyst, chloro-trifluoroethylene can be reacted at 320C, according to U.S Patent Specification 3,755,477, to give a mixture which inter alia con~ains 2-chloro-1,1,1,2-tetrafluoro-ethane (13% of theory) The sarne hydrofluorination process is carried ou-t at 350 to 400C according -to Canadian Patent Specification 849,024; in this process, a considerable part oE the starting material is not converted.
In attempts by the Appliaan~ Company to apply the known gas-phase hydrofluorination processes to the said fluorine-containing ethylenes, the following side reactions were observed: isomeriz-ations, disproportionations, oligomerizations, polymerizations, fragmentation of the C-C bonds and also substitution, for example of chlorine or hydrogen by fluorine. These side reactions reduce the yields and lead to by-products which must then be separated off, frequently at considerable expense. On the other hand, the reaction temperatures in the known processes are uneconomically high. Thus, the life of the catalysts employed is also limited to a considerable extent, in particular when employing ethylenes which contain hydrogen, bromine or iodine and which are therefore capable of poisoning the catalyst at high temperatures.
The object was therefore to provide a simple, productive and environmentally harmless process for the preparation of very pure partially fluorinated ethanes, which can be carried out at the lowest possible temperatures, which proceeds with high selectivity and with high yields, that is to say in which the known side reactions are not involved, and which can easily be applied continuously.
The present invention provides a process for the preparation of very pure fluorine-containing ethanes of the general formula CF3-CEIXY, in which X denotes H or F and Y
denotes H, F, Cl, Br or iodine, from fluorine-containing ethylenes of the general formula CF2=CXY, in which X and Y
d'--''~ -- D~ --have the meaning indicated above, with at least the equimolar amount of hydrogen fluoride, in the gas phase, which process comprises carrying out -the reaction at temperatures of 20-200C and in the presence o a chromium oxyfluoride catalyst which has been treated with hydrogen fluoride and elemental fluorine.
The chromium oxyfluoride catalyst, treated with hydrogen fluoride, which is employed in the process accordiny to the invention can be prepared, for example, by reacting hydrated chromium oxides with hydrogen fluoride (according to German Auslegescnrift 1,252,182) or by heating hydrated chromium trifluoride in the presence of oxygen (United States Patent Specification
Because of ~heir particular chemical and phvsical properties, partially fluorinated ethanes of the general formula , CF3-CHXY
in whi~-h X denotes H or F and Y denotes H, F~ r or I, are suitable for use in nwmerous fields of applica tion, ~or ex~mple as additi~res in gaseous analgesics and ~esthetics~ as heat exchan~e media or as componeIlts of propellanis, Simple and economical proces~es ior the preparation o representatives of this cizss of cQ~pcunds are therefore of interest.
The said partially fluorinated ethanes ~e in ~hemselve~ known and can be prepared by several, gene.ally laboratory-scale, processes. If ~rery pure fluorine-containing ethylenes of th~ general formula CF2=CXY are available in sufficient a~ourlt, hydrofluorination in the gas phase, in the presence of a solid caialyst, is a possible method~
~ he addition of hydrogen fluoride onto fluorine-containing ethylenes, in the gas phase, with the forma-tion of partially fluorinated ethanes in accordance withthe equation ~X X
~C=C ~ f HF ~ F3 CH
63~S
has alr~ady been described for some compounds However, all known fluorination processes in the gas phase require relatively high temperatures~ ge~erally above 250C and in some cases even above 400C. At these temperatures, 5 undesired side reactions necessarily result. For example, in the case of ethylenes which contain chlorine, bromine or iodine atoms, the halogen can be substituted by fluorine. Even in the partially fluorinated athane formed, the halogen ca~ be dis~laced by the fluorine of the hydroge~ fluoride at the high temperatures mentioned.
This reacti~rity ca~ be used diractly for the ~r~paration of F-substituted co~pounds. For exa~ple, aocording to U.S Patent ~pecification 2,951,102, the compound ÇF3CHClF is prepared from CF2BrCHClF by react on wich HF, at 300C, cn a chromium oxyfluoride catalyst.
The hydrofluorination of trifluGroethylQne at reaction temperatures of 350C is described in Germarl ~ffenlegungsschrift 2,837,515 This proce s uses a chromium oxyfluoride catalyst which was prepared accord-ing to British Pa-tent ~pecification 1,307,2~4. The yields of 1,1,1,2-tetrafluorGethane are 90 to 95% o~
theory. The possible residence 'imes lie within narrow limits and the proportion of fluorinated by-products is high Again on a chromium oxyfluoride catalyst, chloro-trifluoroethylene can be reacted at 320C, according to U.S Patent Specification 3,755,477, to give a mixture which inter alia con~ains 2-chloro-1,1,1,2-tetrafluoro-ethane (13% of theory) The sarne hydrofluorination process is carried ou-t at 350 to 400C according -to Canadian Patent Specification 849,024; in this process, a considerable part oE the starting material is not converted.
In attempts by the Appliaan~ Company to apply the known gas-phase hydrofluorination processes to the said fluorine-containing ethylenes, the following side reactions were observed: isomeriz-ations, disproportionations, oligomerizations, polymerizations, fragmentation of the C-C bonds and also substitution, for example of chlorine or hydrogen by fluorine. These side reactions reduce the yields and lead to by-products which must then be separated off, frequently at considerable expense. On the other hand, the reaction temperatures in the known processes are uneconomically high. Thus, the life of the catalysts employed is also limited to a considerable extent, in particular when employing ethylenes which contain hydrogen, bromine or iodine and which are therefore capable of poisoning the catalyst at high temperatures.
The object was therefore to provide a simple, productive and environmentally harmless process for the preparation of very pure partially fluorinated ethanes, which can be carried out at the lowest possible temperatures, which proceeds with high selectivity and with high yields, that is to say in which the known side reactions are not involved, and which can easily be applied continuously.
The present invention provides a process for the preparation of very pure fluorine-containing ethanes of the general formula CF3-CEIXY, in which X denotes H or F and Y
denotes H, F, Cl, Br or iodine, from fluorine-containing ethylenes of the general formula CF2=CXY, in which X and Y
d'--''~ -- D~ --have the meaning indicated above, with at least the equimolar amount of hydrogen fluoride, in the gas phase, which process comprises carrying out -the reaction at temperatures of 20-200C and in the presence o a chromium oxyfluoride catalyst which has been treated with hydrogen fluoride and elemental fluorine.
The chromium oxyfluoride catalyst, treated with hydrogen fluoride, which is employed in the process accordiny to the invention can be prepared, for example, by reacting hydrated chromium oxides with hydrogen fluoride (according to German Auslegescnrift 1,252,182) or by heating hydrated chromium trifluoride in the presence of oxygen (United States Patent Specification
2,745,886).
Those catalysts which are obtained from hydrated chromium oxide by treatment with hydrogen fluoride only require an after-treatment with hydroyen fluoride when they are employed after a relatively long time, for example after a few months, for the process according to the invention. However, if the same catalysts are used immediately after they have been prepared, an after-treatment with hydrogen fluoride is unnecessary. In the case ofthe catalysts prepared from chromium trifluoride, however, the after-treatment with hydrogen fluoride is always necessary.
The after-treatment of the chromium oxyfluoride .,r~
c~t~lysts is carried ou-t either for a relatively long time (mo.re than 4~ hours) with hydrogen fluoride, at temperatures of 250 to 300C, or preferably .t'or a relatively short time (about 5 to 10 hours) with a gas mixture which contains hydrogen fluo~ide an~ elementary M uorine. In this process, elementary fluorine is generally diluted ~ith an inert gas and anhydrous hydro-ge.n fluoride and passed into a tube +'illed with the chl~omium oxyfluoride catalyst and heated to temperatures of 150 to 210C. The ac.tiva~ion time depends on the his~ry of the catalyst and is general'y 5 ~o 10 how~s.
Advantageously, the .low rate per licer of ca~alyst is 0.1 to 5.0 liters/hour for the fluorine me'ered iIl, ~.0 to 3.0 liters/hou~ for Ihe inert gas and 1~ to 5C g/
- 15 hour for the hydrcgen fluoride, Of course, t.he treatment with hydrogen fluoride~,luorir.e can be carried out bv passing the latter r.ot only ~imult~necusly but ~lso in succes.sion, The treatment of a chromium oxyfluo.~ide catalyst ~0 wi~h ~ mixtui~e of hydrogen fluoride and elementary fluorine is substantially known from German Offenlegungs-schrift 2,702,36~ and is used in this case fo. the re-activation of catalysts -~hich are employed for chlorine/
fluorine exchange reactions.
The process according to the invention is generally carried out in the manner of a customary cata-lytic gas/solid reaction by passing a gas mixture, con-sisting of the fluorine-containing ethylene to be reacted and of hydrogen fluoride, through a heatable reaction tube which ls filled with the a~ovementioned pre-treated chromium oxyfluorlde catalyst. The reaction tube is preferably arranged vertically The reaction tube consis-ts of a material, such as nickel, steel, copper or platinum, which is suffi_ ciently resistan+ towards hydrogen fluoride and elemen-tary fluorine, or is provided ~i-th a suitable lining, for ex3mple of pclytetrafluoroethyleile or another suit-able highly fluorinated polymer. The reaction gases 1~ which leave the reaction tube are freed of excess hydrogen fluoride by washing with wa-ter or by absorption in tower~ containing granular sodium fluoride The partially fluorinated ethane purif1ed beforehand ir th~s way is condensed in suitable cooling traps Tne sh~pe of the chrG~ium cxyfluoride catalyst ~mployed is not critical; sphere~, cubes or cylinders having a volllme of 0~01 to ;0 cc are customarily used The use of the compounds trifluoroethvlene, tetrafiuoroethyiene? chlorotrifluoroethylene, bromotri-fluoroethylene or trifluoroiodoethylene is preferredin the process according to the invention. This gives, res~ectively9 1,1,1,2-tetrafluoroethane, pentafluoro-ethane, 2-chloro-1,1,1,2-tetrafiuoroethane, l-bromo-19 2~2,2-tetrafluoroethane or 1,2,2,2-tetrafluoro-1-iodo-ethane in approximately quantitative yields~
To carry out the process according to the inven-tion, the fluorine-containing ethylenes,in the gaseous state, are first mixed with hydrogen fluoride and then passed in-to the reactor filled with the catalys-t.
1~96345 The boiling polnts of a few starting materials are listed in th~ following ~able:
Table 1 __.
Fluorine con~aining Formula Boiling 5 ethylene point/lbar l,l-Difluoroethylene CF2=CH2 -~2C
Trifiuoroethylene CF2=C~F -61C
2-Chloro-l,1-di-fluoroethylene CF2=CHCl -17.7~C
10 1-Bromo-2,2-di-fluoroethylene CF2=C B r + 6.1C
2,2-Difluoro-l~
iodo-ethylene CF~=CHI + ~4C
Tetrafluoroethylene CF2=CF2 76.3 C
15 Chlorotrifluoro-e~ ylene CF2-~FCl -27.95 Bromotriflu~rc- -ethylene ~F2=~FBr _ 4.5C
Trifluoroiodo-20 ethylene C~2=CFI . ~ 29C
- The fluorine-containing ethylenes generally used are o technical purity and are advantageously as ~hydrous as possible. These starting materials can be prepared in ~n easy manner by processes which are in themselves known; some representatives, such as, for ex~mple, tetrafluoroethylene, chlorotrifluoroe-thylene or 1,1-difluoroethylene, are also available on an industrial scale.
At atmospheric pressure, the throughput of fluorine-containing ethylenes is advantageously about 1 to 90 liters (about 0.04 to 4 moles) per liter of cata-. , .
- _ 9 _ lyst and per hour, At higher pressures, the through-put of fluorine-containing ethylenes can be correspondingly higher. Lower throughputs are possible but uneconomi-cal.
The process according to the invention generally takes place at normal pressure, but also permits the application of excess pressure or reduced pressure within wide limits. Thus, the reaction can be carried out at pressures o~ less than 1 bar or also at an excess pres-1" sure of 1 to 10 bars or more, preferably at 1 to 3 bars.
The appiication of excess pressure is preferable, especially for achieving hi~h space-ti~e yields If the starting compounds ~e not an~ydrous, side reaçtion~ (formation of oxygen-con~aining products) can 15 result.
Hydrogen fluoride is generally added w~thout dilution. The amount of hydrogen fluoride metered in in ~le gaseous s~ate is generally between 0,8 and 250 g (3.04 and 12.5 moles respectively) per liter of catalyst and per hour. It should be at least equivalent to, b~t preferably greater than, the amount of the particular fluorine-containing ethyiene e~ployed. The molar ratio of fluorine-~ontaining ethylene to hydrogen fluoride is generally between 1:3 and 1:1, preferably between 1:2 and 1:1 1 and especially between 1:1 5 and 1:1.1. The total amount of hydrogen fluoride passed in is not criti-cal provided that only an excess (relative to the fluorine-containing ethylene employed) is usod. An excess of hydrogen fluoride is favorable inasmuch as a quantitative 3L 3.~;3'~5 conversion of the fluorine-containing ethylene is thereby achieved, Relatively large excesses of hydrogen ~luoride are also possible; however, this increases -the expense involved in the working-up. Excess hydrogen fluoride is either removed from the reaction-gas by washing with water or dilute sodium hydroxide solution or is absorbed at room temperature in towers containing granular sodium fluoride. Because the hydrogen fluoride can be thermally desorbed again after absorption on sodium fluoride and can be re-employed, the losses of hydrogen fluoride remain very small with this procedure.
Working-up by fractional distillation is also possible.
In general, the reaction is carried out without the addition of an inert gas. Although dilution, for example with nitrogen or another inert gas, is possible, it only brings about a minimal increase in the yield.
The reactions are carried out at te~peratures of 20 to 200C, advantageously at 40 to 190 C and espe-cially at 60 to 180C, The residence time of fluorine-containing ethylene, or of the fluorine-containing ethane formed therefrom, in the reactor is not critical. In both cases, it can vary between a few seconds and a few minutes; it only has an upper limit as a result of economic considerations. It is to be regarded as a particular advantage of the process according to the invention that the residence time can be varied within wide limits without the composition of the reaction pro-duct being influenced thereby.
ti 345 With the process according to the inventlon, a continuous procedure, that is to say continuous passage o~ the st~rting materials, continuous recycling of the excess hydrogen fluoride and also continuous isolation of the partially fluorinated ethane formed, is easily possible~ Particular advantages of the continuous procedure lie in the good utilization of the starting materials employed and in the small amount of effluent an~ of~-gas formed.
'~ith the process according to the invention, the con~ersion of the ~lucrine-containing ethylenesemplo-yed ~s generally more than 95%, but fre~uently 9~ - 100%.
Beca~se of the high selectivity of the proce~s acc~r~ing to the invention, the yields of p&-ti~lly fluori.nated ~thanes ar~ likewise more than 95%, but fre-quently more than 9~%. The ethanes are thus obtained in high !urity. ThQ ~r~cess àccording to the inven~
tion prove~ advantageous aboYe all insofar as s~de reactions are virtually completely suppressed and the working-up conse~uently proves exceptionally simple.
The ollowing table shows the boiling points of the partially fluorinated ethanes which can be prepared - fro~. the iluorine-containing etnylenes of Table 1.
i345 Table 2: Ethanes Name Formula Boilin~
point/lbar l,l,l-Trifluoroethane ~F~-CH3 _47,8C
1,1,1,2-Tetrafluoroethane CF3-CH2F -26.5C
2-Chloro-l,l,l-trifluoroethane CF3-CH2Cl + 6 1 C
l-Bromo-2,2,2-trifluoroethane CF3-CH2Br +26C
2,2,2-Trifluoro-l~iodo~ethane CF~-CH2I +55C
Pentafluoroethane CF3 CHF2 _48 5C
2-Chloro-1,1,1?2-tetrafluoro-ethane CF3-CHClF -12C
l-Bromo-1,2,2,2-tetrafluoro-ethane CF3-CHBrF ~ 7C
1,2,2,2-Tetrafluoro-l-iodo-15 ethane CF3-CHFI ~39C
It is known from German Offenlegungsschrift 2,712,732 that perfluoropropylene reacts with hydrogen t ' fluoride at temperatures of 100 to 350C, in the pre-sence of chromium oxyfluoride catalysts. In this reac-20 tion, the yields of 2H-heptafluoropropane, at reaction temperatures below 200C, are only moderate. For example, at 160 to 170C, they are only 82% of theory.
Moreover~ the significance of the pre~treatment of the catalyst with hydrogen fluoride is not evident from this 25 literature reference.
It is surprising that, in the presence of the chromium oxyfluoride catalysts subjected to an after-treatment with HF, the hydrofluorination of fluorine-containing ethylenes proceeds with high conversions9 30 which are frequently quantitative, and with exceptionally 6~5 high selectivity It is particul~ ly surprising -that the reaction temperatures of the process according to the invention are unexpectedly low, in comparison with the state of the art, The process according to the i~vention represents a considerable technical advance because it permits the preparation of partially fluorinated ethanes in yields of more than 95%, in some cases up to 99%, starting from the ~luorine-containing ethylenesj which are either obtainable industrially or are readily accessible via other industrial intermediates, with optimum utilization of the starting materials, without substantial formation of the customary isomerization products, disproportiona-tion products, oligomerization products, polymerization products, fragmentation products or substitution products As a consequence of -this, working-up is simple and a high degree of purity of the end products can easily be achieved. Furthermore, the process according to the in~ention is of great interest because of the low reac- -tion temperatures and the consequent long life of the catalysts employed.
The process is illustrated in greater detail by the following examples:
~ ple 1 The activation of the chromium oxyfluoride catalysts with hydrogen fluoride or with a gas mixture of hydrogen fluoride and elementary fluorine, and the sub-sequent hydrofluorination of the fluorine-containing ethylenes, were carried out in the same pilot plant.
, ~ 14 -This consists of a vertlcally standing nickel tube having a length o~ 150 cm and an internal diameter of 5 cm, The reactor is heated externally with a heating mantle; a V~-steel tube having an external dia-meter of 0,6 cm, an internal diame-ter of 0.4 cm and a length of 145 cm, through which a thermocouple for measur-ing the internal temperature can be introduced at any desired level of the reac-tor, runs axially through the inside of the reactor tube.. The granular ca-talyst material is kept at the desired 'evel of the tube by means of a sieve part mounted inside the reaction tube, At the lower end ol tlle reaGtor, there is a nickel evaporation ~essel whiGh can be heated separately, into which the lines for gaseous hydrogen flucride, dilute~
- 15 o~ undil~ted .luorlne gas &nd the gaseous fluorine-co~taining ethylene (in Example 1~ difluoroethylene~
lead. The evaporation vessel is kept at a temperature between the bolling point of hydrogen fluoride (+20C~
and the reactor temperature, From the upper end of t.he nic~el reactor, a line leads intG a washing receiver filled with water, in which receiver hydrogen fluoride which has nct reacted in the hydrofluorination is trapped and sampledby titration. ~uring the activa-tion with ele~entary fluorine, a receiver containing hexafluoropropene trimer is inserted between the reactor outlet and the washing vessel. Excess fluorine can thus be absorbed without danger (compare German Offenlegungsschrift 2,3323097); additional fluorine t.ests are c.arried out during the activation with potassium 1~163f~5 .
- ~5 -iodiAe paper.
Elementary fluorine (F2) is -tc~ken from a commer-cially available steel cylinder, measured with a pre-calibrated differential pressure flowmeter~ diluted with nitrogen and passed into the reactor. A riser mano~
meter ~or observing the back pressure which develops ~s fitted upstream of the fiuorine flowmeter.and simll-taneously s~rves as a ~afe-ty valve The back-pressure meters are filled with per~luorinated polyether oils.
~0 The hydrogen fluori~e (H~) employed has the com~rcially available purity of more than 99~0 and is metered using a measuring arrangemen~ which is basically similar to tn~t described for the fluorine. Radiant hea~ers are addi' onally fit-ted in order t~ pre~e.it H~
from cGndensing in the lines up to ~r,e evaporaTor.
600 ml (bulk volume~ of a chromium cxyfluoride catalyst ~rhich has be~n prepared by fluorinating hydr~ted chromium sesquioxide with hydrogen fluoride according to German .~uslegeschrift 1,252,182 ~re init ally intro-duced i-nto the reactor tube. The catalyst initia'iy ntroduced is activated by treatment, at an nternal temperature of 150C, for 10 hours, with a gas mixture consisting of 0.35 liter/hour of fluorine, 0.5 liter/ho~lr of nitrogen and 15 g/hour of hydrogen fluoride; it is then flushed with 15 g/hour of hydrogen fluoride at the same internal temperature, for 5 hours.
The l,l-difluoroethylene is taken from a commer-cially available steel cylinder For hydrofluorination, a total of 420 g (6.56 moles) of C~2=CH2 and 237 g
Those catalysts which are obtained from hydrated chromium oxide by treatment with hydrogen fluoride only require an after-treatment with hydroyen fluoride when they are employed after a relatively long time, for example after a few months, for the process according to the invention. However, if the same catalysts are used immediately after they have been prepared, an after-treatment with hydrogen fluoride is unnecessary. In the case ofthe catalysts prepared from chromium trifluoride, however, the after-treatment with hydrogen fluoride is always necessary.
The after-treatment of the chromium oxyfluoride .,r~
c~t~lysts is carried ou-t either for a relatively long time (mo.re than 4~ hours) with hydrogen fluoride, at temperatures of 250 to 300C, or preferably .t'or a relatively short time (about 5 to 10 hours) with a gas mixture which contains hydrogen fluo~ide an~ elementary M uorine. In this process, elementary fluorine is generally diluted ~ith an inert gas and anhydrous hydro-ge.n fluoride and passed into a tube +'illed with the chl~omium oxyfluoride catalyst and heated to temperatures of 150 to 210C. The ac.tiva~ion time depends on the his~ry of the catalyst and is general'y 5 ~o 10 how~s.
Advantageously, the .low rate per licer of ca~alyst is 0.1 to 5.0 liters/hour for the fluorine me'ered iIl, ~.0 to 3.0 liters/hou~ for Ihe inert gas and 1~ to 5C g/
- 15 hour for the hydrcgen fluoride, Of course, t.he treatment with hydrogen fluoride~,luorir.e can be carried out bv passing the latter r.ot only ~imult~necusly but ~lso in succes.sion, The treatment of a chromium oxyfluo.~ide catalyst ~0 wi~h ~ mixtui~e of hydrogen fluoride and elementary fluorine is substantially known from German Offenlegungs-schrift 2,702,36~ and is used in this case fo. the re-activation of catalysts -~hich are employed for chlorine/
fluorine exchange reactions.
The process according to the invention is generally carried out in the manner of a customary cata-lytic gas/solid reaction by passing a gas mixture, con-sisting of the fluorine-containing ethylene to be reacted and of hydrogen fluoride, through a heatable reaction tube which ls filled with the a~ovementioned pre-treated chromium oxyfluorlde catalyst. The reaction tube is preferably arranged vertically The reaction tube consis-ts of a material, such as nickel, steel, copper or platinum, which is suffi_ ciently resistan+ towards hydrogen fluoride and elemen-tary fluorine, or is provided ~i-th a suitable lining, for ex3mple of pclytetrafluoroethyleile or another suit-able highly fluorinated polymer. The reaction gases 1~ which leave the reaction tube are freed of excess hydrogen fluoride by washing with wa-ter or by absorption in tower~ containing granular sodium fluoride The partially fluorinated ethane purif1ed beforehand ir th~s way is condensed in suitable cooling traps Tne sh~pe of the chrG~ium cxyfluoride catalyst ~mployed is not critical; sphere~, cubes or cylinders having a volllme of 0~01 to ;0 cc are customarily used The use of the compounds trifluoroethvlene, tetrafiuoroethyiene? chlorotrifluoroethylene, bromotri-fluoroethylene or trifluoroiodoethylene is preferredin the process according to the invention. This gives, res~ectively9 1,1,1,2-tetrafluoroethane, pentafluoro-ethane, 2-chloro-1,1,1,2-tetrafiuoroethane, l-bromo-19 2~2,2-tetrafluoroethane or 1,2,2,2-tetrafluoro-1-iodo-ethane in approximately quantitative yields~
To carry out the process according to the inven-tion, the fluorine-containing ethylenes,in the gaseous state, are first mixed with hydrogen fluoride and then passed in-to the reactor filled with the catalys-t.
1~96345 The boiling polnts of a few starting materials are listed in th~ following ~able:
Table 1 __.
Fluorine con~aining Formula Boiling 5 ethylene point/lbar l,l-Difluoroethylene CF2=CH2 -~2C
Trifiuoroethylene CF2=C~F -61C
2-Chloro-l,1-di-fluoroethylene CF2=CHCl -17.7~C
10 1-Bromo-2,2-di-fluoroethylene CF2=C B r + 6.1C
2,2-Difluoro-l~
iodo-ethylene CF~=CHI + ~4C
Tetrafluoroethylene CF2=CF2 76.3 C
15 Chlorotrifluoro-e~ ylene CF2-~FCl -27.95 Bromotriflu~rc- -ethylene ~F2=~FBr _ 4.5C
Trifluoroiodo-20 ethylene C~2=CFI . ~ 29C
- The fluorine-containing ethylenes generally used are o technical purity and are advantageously as ~hydrous as possible. These starting materials can be prepared in ~n easy manner by processes which are in themselves known; some representatives, such as, for ex~mple, tetrafluoroethylene, chlorotrifluoroe-thylene or 1,1-difluoroethylene, are also available on an industrial scale.
At atmospheric pressure, the throughput of fluorine-containing ethylenes is advantageously about 1 to 90 liters (about 0.04 to 4 moles) per liter of cata-. , .
- _ 9 _ lyst and per hour, At higher pressures, the through-put of fluorine-containing ethylenes can be correspondingly higher. Lower throughputs are possible but uneconomi-cal.
The process according to the invention generally takes place at normal pressure, but also permits the application of excess pressure or reduced pressure within wide limits. Thus, the reaction can be carried out at pressures o~ less than 1 bar or also at an excess pres-1" sure of 1 to 10 bars or more, preferably at 1 to 3 bars.
The appiication of excess pressure is preferable, especially for achieving hi~h space-ti~e yields If the starting compounds ~e not an~ydrous, side reaçtion~ (formation of oxygen-con~aining products) can 15 result.
Hydrogen fluoride is generally added w~thout dilution. The amount of hydrogen fluoride metered in in ~le gaseous s~ate is generally between 0,8 and 250 g (3.04 and 12.5 moles respectively) per liter of catalyst and per hour. It should be at least equivalent to, b~t preferably greater than, the amount of the particular fluorine-containing ethyiene e~ployed. The molar ratio of fluorine-~ontaining ethylene to hydrogen fluoride is generally between 1:3 and 1:1, preferably between 1:2 and 1:1 1 and especially between 1:1 5 and 1:1.1. The total amount of hydrogen fluoride passed in is not criti-cal provided that only an excess (relative to the fluorine-containing ethylene employed) is usod. An excess of hydrogen fluoride is favorable inasmuch as a quantitative 3L 3.~;3'~5 conversion of the fluorine-containing ethylene is thereby achieved, Relatively large excesses of hydrogen ~luoride are also possible; however, this increases -the expense involved in the working-up. Excess hydrogen fluoride is either removed from the reaction-gas by washing with water or dilute sodium hydroxide solution or is absorbed at room temperature in towers containing granular sodium fluoride. Because the hydrogen fluoride can be thermally desorbed again after absorption on sodium fluoride and can be re-employed, the losses of hydrogen fluoride remain very small with this procedure.
Working-up by fractional distillation is also possible.
In general, the reaction is carried out without the addition of an inert gas. Although dilution, for example with nitrogen or another inert gas, is possible, it only brings about a minimal increase in the yield.
The reactions are carried out at te~peratures of 20 to 200C, advantageously at 40 to 190 C and espe-cially at 60 to 180C, The residence time of fluorine-containing ethylene, or of the fluorine-containing ethane formed therefrom, in the reactor is not critical. In both cases, it can vary between a few seconds and a few minutes; it only has an upper limit as a result of economic considerations. It is to be regarded as a particular advantage of the process according to the invention that the residence time can be varied within wide limits without the composition of the reaction pro-duct being influenced thereby.
ti 345 With the process according to the inventlon, a continuous procedure, that is to say continuous passage o~ the st~rting materials, continuous recycling of the excess hydrogen fluoride and also continuous isolation of the partially fluorinated ethane formed, is easily possible~ Particular advantages of the continuous procedure lie in the good utilization of the starting materials employed and in the small amount of effluent an~ of~-gas formed.
'~ith the process according to the invention, the con~ersion of the ~lucrine-containing ethylenesemplo-yed ~s generally more than 95%, but fre~uently 9~ - 100%.
Beca~se of the high selectivity of the proce~s acc~r~ing to the invention, the yields of p&-ti~lly fluori.nated ~thanes ar~ likewise more than 95%, but fre-quently more than 9~%. The ethanes are thus obtained in high !urity. ThQ ~r~cess àccording to the inven~
tion prove~ advantageous aboYe all insofar as s~de reactions are virtually completely suppressed and the working-up conse~uently proves exceptionally simple.
The ollowing table shows the boiling points of the partially fluorinated ethanes which can be prepared - fro~. the iluorine-containing etnylenes of Table 1.
i345 Table 2: Ethanes Name Formula Boilin~
point/lbar l,l,l-Trifluoroethane ~F~-CH3 _47,8C
1,1,1,2-Tetrafluoroethane CF3-CH2F -26.5C
2-Chloro-l,l,l-trifluoroethane CF3-CH2Cl + 6 1 C
l-Bromo-2,2,2-trifluoroethane CF3-CH2Br +26C
2,2,2-Trifluoro-l~iodo~ethane CF~-CH2I +55C
Pentafluoroethane CF3 CHF2 _48 5C
2-Chloro-1,1,1?2-tetrafluoro-ethane CF3-CHClF -12C
l-Bromo-1,2,2,2-tetrafluoro-ethane CF3-CHBrF ~ 7C
1,2,2,2-Tetrafluoro-l-iodo-15 ethane CF3-CHFI ~39C
It is known from German Offenlegungsschrift 2,712,732 that perfluoropropylene reacts with hydrogen t ' fluoride at temperatures of 100 to 350C, in the pre-sence of chromium oxyfluoride catalysts. In this reac-20 tion, the yields of 2H-heptafluoropropane, at reaction temperatures below 200C, are only moderate. For example, at 160 to 170C, they are only 82% of theory.
Moreover~ the significance of the pre~treatment of the catalyst with hydrogen fluoride is not evident from this 25 literature reference.
It is surprising that, in the presence of the chromium oxyfluoride catalysts subjected to an after-treatment with HF, the hydrofluorination of fluorine-containing ethylenes proceeds with high conversions9 30 which are frequently quantitative, and with exceptionally 6~5 high selectivity It is particul~ ly surprising -that the reaction temperatures of the process according to the invention are unexpectedly low, in comparison with the state of the art, The process according to the i~vention represents a considerable technical advance because it permits the preparation of partially fluorinated ethanes in yields of more than 95%, in some cases up to 99%, starting from the ~luorine-containing ethylenesj which are either obtainable industrially or are readily accessible via other industrial intermediates, with optimum utilization of the starting materials, without substantial formation of the customary isomerization products, disproportiona-tion products, oligomerization products, polymerization products, fragmentation products or substitution products As a consequence of -this, working-up is simple and a high degree of purity of the end products can easily be achieved. Furthermore, the process according to the in~ention is of great interest because of the low reac- -tion temperatures and the consequent long life of the catalysts employed.
The process is illustrated in greater detail by the following examples:
~ ple 1 The activation of the chromium oxyfluoride catalysts with hydrogen fluoride or with a gas mixture of hydrogen fluoride and elementary fluorine, and the sub-sequent hydrofluorination of the fluorine-containing ethylenes, were carried out in the same pilot plant.
, ~ 14 -This consists of a vertlcally standing nickel tube having a length o~ 150 cm and an internal diameter of 5 cm, The reactor is heated externally with a heating mantle; a V~-steel tube having an external dia-meter of 0,6 cm, an internal diame-ter of 0.4 cm and a length of 145 cm, through which a thermocouple for measur-ing the internal temperature can be introduced at any desired level of the reac-tor, runs axially through the inside of the reactor tube.. The granular ca-talyst material is kept at the desired 'evel of the tube by means of a sieve part mounted inside the reaction tube, At the lower end ol tlle reaGtor, there is a nickel evaporation ~essel whiGh can be heated separately, into which the lines for gaseous hydrogen flucride, dilute~
- 15 o~ undil~ted .luorlne gas &nd the gaseous fluorine-co~taining ethylene (in Example 1~ difluoroethylene~
lead. The evaporation vessel is kept at a temperature between the bolling point of hydrogen fluoride (+20C~
and the reactor temperature, From the upper end of t.he nic~el reactor, a line leads intG a washing receiver filled with water, in which receiver hydrogen fluoride which has nct reacted in the hydrofluorination is trapped and sampledby titration. ~uring the activa-tion with ele~entary fluorine, a receiver containing hexafluoropropene trimer is inserted between the reactor outlet and the washing vessel. Excess fluorine can thus be absorbed without danger (compare German Offenlegungsschrift 2,3323097); additional fluorine t.ests are c.arried out during the activation with potassium 1~163f~5 .
- ~5 -iodiAe paper.
Elementary fluorine (F2) is -tc~ken from a commer-cially available steel cylinder, measured with a pre-calibrated differential pressure flowmeter~ diluted with nitrogen and passed into the reactor. A riser mano~
meter ~or observing the back pressure which develops ~s fitted upstream of the fiuorine flowmeter.and simll-taneously s~rves as a ~afe-ty valve The back-pressure meters are filled with per~luorinated polyether oils.
~0 The hydrogen fluori~e (H~) employed has the com~rcially available purity of more than 99~0 and is metered using a measuring arrangemen~ which is basically similar to tn~t described for the fluorine. Radiant hea~ers are addi' onally fit-ted in order t~ pre~e.it H~
from cGndensing in the lines up to ~r,e evaporaTor.
600 ml (bulk volume~ of a chromium cxyfluoride catalyst ~rhich has be~n prepared by fluorinating hydr~ted chromium sesquioxide with hydrogen fluoride according to German .~uslegeschrift 1,252,182 ~re init ally intro-duced i-nto the reactor tube. The catalyst initia'iy ntroduced is activated by treatment, at an nternal temperature of 150C, for 10 hours, with a gas mixture consisting of 0.35 liter/hour of fluorine, 0.5 liter/ho~lr of nitrogen and 15 g/hour of hydrogen fluoride; it is then flushed with 15 g/hour of hydrogen fluoride at the same internal temperature, for 5 hours.
The l,l-difluoroethylene is taken from a commer-cially available steel cylinder For hydrofluorination, a total of 420 g (6.56 moles) of C~2=CH2 and 237 g
3~5 ~ 16 -(11.85 moles) of HF, corresponding to a molar ra-tio CF2=CH~:HF of 1:1,81, are passed in over the activated chromium oxyfluoride catalyst, at reactor temperatures of 80C (at the start) to 98C (after commencement of the exother~ic add~'ion reaction), in the course of 6 hours.
5.23 moles of HF are trapped in the wash water.
For drying, the gaseous reaction product is passed through a CaC12 ~rying tower and ~hen condensed in a high-efficiency trap cooled with sol,d carbon dioxide.
Measurement of this crude product by gas chLromatograp'ny on a ~ PGR~ K column gi~esthe foll~ng com~osition:
CF3 CH3 ~9~5 %
CF2-C~2 o 3 %
3 ~0~05 o~
~H2F2 0~05 %
C~2~cH3 ~0.05 h The condensed crude produGt weighs 5~, g, ~he - yield of CF3-CH3 is thu~ 97.3% of theory, relative to the 20 CF2=C~I2 reacted. Further identification of 1,1,1-trlfluoroethane is carried out by means of infra-red9 9F ~nd lH N~R spectra. The boiling point of the pro-duct is -~8 to -47C.
Example 2 Using the experimental arrangement of Example (1), trifluoroethylene is hydrofluorinated by passing a total of 235 g (2.87 moles) of CF2=CHF, which has been prepared by dehalogenating CBrF2-CHClF, and 8~ g (4.15 moles) of HF~ corresponding to a molar ratio of CF2=CHF:HF of 1:1.45, over the chromium oxyfluoride catalyst used in Example (1)~
at temperatures of 124 to 143C, in the course of 3 hours.
In the wash water, 1.25 moles of HF are deter-mined by titration. The gas chromatographic recording of the crude product collected in the trap ~ives the following values:
C~3 CH2F 99.7 ~
CF2=CHF c 0.05 %
CHF3 ~ 0 05 %
3 3 ~ 05 %
The condensate weighs 2~6.5 g; the yield of 1,1,1,2-tetrafluoroeth~ne i~. thus 97.6% of theory, Iela-~ive to the CF2=CHF reacted. The characterization of 1,1,1,2-tetrafluoroe-thane ~s carried out by means of IR9 19F and lH NMR measurements; the ~oiling pcint is -27C
to -25C.
Comp&~ison Example 1 .. Using -the experimentai arrangemerlt of E~.ample (1), 600 ml (bulk volume) of a chromium oYyfluoride cata.Lyst which has been prepared according to German Auslegeschri.t 19 252,182 are initially introduced. In this case, the catalyst material i5 initially pre-treated only -~ith hydrogen fluoride; in this proc~ss, a total of 1,080 g of HF are passed over the catalyst initially introd~ced, . 25 at a rate of 15 g/hour~ at temperatures of 330C to 350C, in the course of 72 hours.
A total of 243 g (2 96 moles) of CF2=CHF and ~6 g (4.30 moles) of HF, corresponding to a molar ratio CF2=CHF:~ of 1:1.45, are passed over the catalyst prepared in the manner described3 a-t tempera-tures of 125 to 142C~ iIl the c~urse o~ 3 hours 1,45 ~oles of HF are trapped in the wash wa-ter.
The condensed crude product has the follo~ing composition according to measurement by gas chro~atography:
CF3-CH~F 95.8 %
~F2=CHF 4.0 ~
CHF3 0.05 %
~F3CH3 f 0 05 %
l~he crude product has a weight of 29~.5 g; the yield of CF3-CH2F is thus 97% of theory, relative to the CF2=CHF rèacted, but the conversion cf CF~=CHF only reaches about 960~.
Exani~le 3 Usin~ the experimental arrangemen' of F~ample (1)9 the catalyst used in Comparison Example (1) is ~ctiv~ted, a~ described in Example (1), by pre treatment with a gas mixture consisting ~f Q.35 liter/hour o~ fluorir.e, 0.5 liter]hour of N2 and 15 g/hour of HF, at an ir,terna' te~perature cf 190 to 195C, for 10 hGurs. It is then flushed with 15 g/hour of HF, at 1905, for 5 hours.
A gas mixture consi~ting of a total of 1,698 g ~20.7 moles) of CF2=CHF and 666 g (33.3 moles) of ~, this being a molar ratio CF2=CHF:HF of 1:1.61, is passed over the chromium oxyfluoride catalyst prepared in the manner described, at an internal temperature of 75C (a-t `the start) to 96C (caused by the heat of reaction), in the course of 26 hours.
12.55 moles of HF are found in the wash water.
34~
Measurements by gas chromatography give the following composition for the crude product trapped:
CF3-CH2F 99.8%
CF2=CHF c 0.05~O
3 ~ 0.05 The condensate weighs 2,088 g; the yield of CF3-CH2F ls thus about 99% of theory, relative to CF2=CHF reacted; in this example, the latter could be quantitatively converted at very moderate temperatures.
Example 4 Using the experimental apparatus of Exarnple (l), a gas mixture consisting of a total of 510 g (5.18 moles) of 2-chloro-1, l-difluoroethylene, which has been prepared by dechlorinating l,1,2-trichloro-2,2-difluoroethane, and 153 g (7.65 moles) of HF, this being a molar ratio CF2=CHCl:HF QE 1:1.48, is passed over the chromium oxyEluoride catalyst used in Example (3), at an internal temperature of 120 to 131C, in the course of 6.0 hours.
In the wash water, 2.33 moles of HF and 0.04 mole of ~ICl are determined by titration. According to gas chromatographic investigations, the crude product consists oE the following constituents:
CF2=CHC1 ~ 0.05%
CF -CH F 0.8%
The crude product trapped has a weigh-t of 603 g;
~o -~he resu~ting yield of 2-chloro-1,1,1-tri M uoroethane is thus 97,2S~ of theory, relative -to the CF2=CHCl reacted, The ethane obtained, namely CF~-CH2Cl, was further charac-terized by recording IR, 19F and lH NMR spectra and also 5 by dete.mining the boiling poin~ of 16C to ~6.5C.
Exam~le 5 ~ or the hydrofluorination of tetrafluoroethylene, which is empioyed n the high purity required for poly-merizations, 600 ml (bulk volume) of chromium oxyfluoride catalyst are pre-treated, in the apparatus use~ in Example (1), with a gas mixture consisting of F2~ HF and N2, as descrihed in Ex~ple fl).
A total of 370 g (3.,0 moles~ of CF2=CF2 and l?o g (8.5 mo es) of HF, correspondin~ to a mo ar ratio CF~=CF2.HF of 1:2 3, are passed over the ca-talyst pre-treated in this way, ~t an internal temperature of 165 tc 179~C~ isl the course of 5.0 hGurs.
5.23 moles of HF are trapped in the wash water.
For drying, the gaseous reaction product is passed through a CaC12 ~rying tower and ~hen condensed in a high-efficiency trap cooled with sol,d carbon dioxide.
Measurement of this crude product by gas chLromatograp'ny on a ~ PGR~ K column gi~esthe foll~ng com~osition:
CF3 CH3 ~9~5 %
CF2-C~2 o 3 %
3 ~0~05 o~
~H2F2 0~05 %
C~2~cH3 ~0.05 h The condensed crude produGt weighs 5~, g, ~he - yield of CF3-CH3 is thu~ 97.3% of theory, relative to the 20 CF2=C~I2 reacted. Further identification of 1,1,1-trlfluoroethane is carried out by means of infra-red9 9F ~nd lH N~R spectra. The boiling point of the pro-duct is -~8 to -47C.
Example 2 Using the experimental arrangement of Example (1), trifluoroethylene is hydrofluorinated by passing a total of 235 g (2.87 moles) of CF2=CHF, which has been prepared by dehalogenating CBrF2-CHClF, and 8~ g (4.15 moles) of HF~ corresponding to a molar ratio of CF2=CHF:HF of 1:1.45, over the chromium oxyfluoride catalyst used in Example (1)~
at temperatures of 124 to 143C, in the course of 3 hours.
In the wash water, 1.25 moles of HF are deter-mined by titration. The gas chromatographic recording of the crude product collected in the trap ~ives the following values:
C~3 CH2F 99.7 ~
CF2=CHF c 0.05 %
CHF3 ~ 0 05 %
3 3 ~ 05 %
The condensate weighs 2~6.5 g; the yield of 1,1,1,2-tetrafluoroeth~ne i~. thus 97.6% of theory, Iela-~ive to the CF2=CHF reacted. The characterization of 1,1,1,2-tetrafluoroe-thane ~s carried out by means of IR9 19F and lH NMR measurements; the ~oiling pcint is -27C
to -25C.
Comp&~ison Example 1 .. Using -the experimentai arrangemerlt of E~.ample (1), 600 ml (bulk volume) of a chromium oYyfluoride cata.Lyst which has been prepared according to German Auslegeschri.t 19 252,182 are initially introduced. In this case, the catalyst material i5 initially pre-treated only -~ith hydrogen fluoride; in this proc~ss, a total of 1,080 g of HF are passed over the catalyst initially introd~ced, . 25 at a rate of 15 g/hour~ at temperatures of 330C to 350C, in the course of 72 hours.
A total of 243 g (2 96 moles) of CF2=CHF and ~6 g (4.30 moles) of HF, corresponding to a molar ratio CF2=CHF:~ of 1:1.45, are passed over the catalyst prepared in the manner described3 a-t tempera-tures of 125 to 142C~ iIl the c~urse o~ 3 hours 1,45 ~oles of HF are trapped in the wash wa-ter.
The condensed crude product has the follo~ing composition according to measurement by gas chro~atography:
CF3-CH~F 95.8 %
~F2=CHF 4.0 ~
CHF3 0.05 %
~F3CH3 f 0 05 %
l~he crude product has a weight of 29~.5 g; the yield of CF3-CH2F is thus 97% of theory, relative to the CF2=CHF rèacted, but the conversion cf CF~=CHF only reaches about 960~.
Exani~le 3 Usin~ the experimental arrangemen' of F~ample (1)9 the catalyst used in Comparison Example (1) is ~ctiv~ted, a~ described in Example (1), by pre treatment with a gas mixture consisting ~f Q.35 liter/hour o~ fluorir.e, 0.5 liter]hour of N2 and 15 g/hour of HF, at an ir,terna' te~perature cf 190 to 195C, for 10 hGurs. It is then flushed with 15 g/hour of HF, at 1905, for 5 hours.
A gas mixture consi~ting of a total of 1,698 g ~20.7 moles) of CF2=CHF and 666 g (33.3 moles) of ~, this being a molar ratio CF2=CHF:HF of 1:1.61, is passed over the chromium oxyfluoride catalyst prepared in the manner described, at an internal temperature of 75C (a-t `the start) to 96C (caused by the heat of reaction), in the course of 26 hours.
12.55 moles of HF are found in the wash water.
34~
Measurements by gas chromatography give the following composition for the crude product trapped:
CF3-CH2F 99.8%
CF2=CHF c 0.05~O
3 ~ 0.05 The condensate weighs 2,088 g; the yield of CF3-CH2F ls thus about 99% of theory, relative to CF2=CHF reacted; in this example, the latter could be quantitatively converted at very moderate temperatures.
Example 4 Using the experimental apparatus of Exarnple (l), a gas mixture consisting of a total of 510 g (5.18 moles) of 2-chloro-1, l-difluoroethylene, which has been prepared by dechlorinating l,1,2-trichloro-2,2-difluoroethane, and 153 g (7.65 moles) of HF, this being a molar ratio CF2=CHCl:HF QE 1:1.48, is passed over the chromium oxyEluoride catalyst used in Example (3), at an internal temperature of 120 to 131C, in the course of 6.0 hours.
In the wash water, 2.33 moles of HF and 0.04 mole of ~ICl are determined by titration. According to gas chromatographic investigations, the crude product consists oE the following constituents:
CF2=CHC1 ~ 0.05%
CF -CH F 0.8%
The crude product trapped has a weigh-t of 603 g;
~o -~he resu~ting yield of 2-chloro-1,1,1-tri M uoroethane is thus 97,2S~ of theory, relative -to the CF2=CHCl reacted, The ethane obtained, namely CF~-CH2Cl, was further charac-terized by recording IR, 19F and lH NMR spectra and also 5 by dete.mining the boiling poin~ of 16C to ~6.5C.
Exam~le 5 ~ or the hydrofluorination of tetrafluoroethylene, which is empioyed n the high purity required for poly-merizations, 600 ml (bulk volume) of chromium oxyfluoride catalyst are pre-treated, in the apparatus use~ in Example (1), with a gas mixture consisting of F2~ HF and N2, as descrihed in Ex~ple fl).
A total of 370 g (3.,0 moles~ of CF2=CF2 and l?o g (8.5 mo es) of HF, correspondin~ to a mo ar ratio CF~=CF2.HF of 1:2 3, are passed over the ca-talyst pre-treated in this way, ~t an internal temperature of 165 tc 179~C~ isl the course of 5.0 hGurs.
4 95 moles of ~F ~ e trapped in the ~ash water.
Gas chromatographic analysis of the resulting crude pro-duct gives the following values:
CF3-CHF2 92.5 %
CF2=CF2 6,3 %
C~F3 0.2 %
CF3-CF3 0.25 %
cyclo-C4F8 ~ 1 %
The resulting condensate weighs 417 g; the yield of pentafluoroethane is thus about 93% of theory, relative to the CF2=CF2 reacted. The pentafluoroethane, CF3-CHF2, was further characterized by IR and NMR measurements.
;3~5 Subsequent lo~-temperature distillation gave Q ~raction o~ 372 g in the boiling range from -49 to -47,5C/normal pressure, consisting of over ggyO o~ pentafluoroethane, Comparison Example 2 Using the experimental arra~.gement ~f Example (1), ~illed with the chromium o~yfluoride catalyst of Example
Gas chromatographic analysis of the resulting crude pro-duct gives the following values:
CF3-CHF2 92.5 %
CF2=CF2 6,3 %
C~F3 0.2 %
CF3-CF3 0.25 %
cyclo-C4F8 ~ 1 %
The resulting condensate weighs 417 g; the yield of pentafluoroethane is thus about 93% of theory, relative to the CF2=CF2 reacted. The pentafluoroethane, CF3-CHF2, was further characterized by IR and NMR measurements.
;3~5 Subsequent lo~-temperature distillation gave Q ~raction o~ 372 g in the boiling range from -49 to -47,5C/normal pressure, consisting of over ggyO o~ pentafluoroethane, Comparison Example 2 Using the experimental arra~.gement ~f Example (1), ~illed with the chromium o~yfluoride catalyst of Example
5, a total of 202~5 g (2.-03 moles) of CF2=CF2 and 113 g (5,65 moles) of HF, correspondi~g to a molar ratio C~2=CF2:~F of 1:2,8, are reacted at a temperature of 280C to 288C, in the course of 3.0 hours.
4.C5 moles of HF are determined in the wash water.
Gas chromatographic measurement of the crude product trappe~ gives the following data:
C~3-CHF~ 83.~ %
2 2 ~ 0 05 %
3.5 ~
~YCl-c4F8 3.3 %
~6F12 ~.5 %
FuL~tnermore, wllite solid residues consisting of polytetrafluoroethylene are observed on the cataly~t material, With a weight of 184 g for the condensate (crude product), the yield of pentafluoroethane in this comparison example is only about ~3% of theory, relative to the CF2=CF2 reacted. Although an increase in the reactor temperature leads to a quantitative conversion of ethylene, it gives rise to a higher proportion of by-products.
Exam~le 6 For the hydrofluorination of chlorotrifluoro-.
ethylene, which is easily obtainable in high purity as anindustrial intermediate, the chromium oxyEluoride catal~st used in Example (4) is initially introduced into the experimental apparatus of Example (1).
At an internal temperature oE 170 to 178C, a total of 605 g (5.19 moles) of CF2=CFCl and 152 g (7.6 moles) of HF, corresponding to a molar ratio CF2=CFCl:HF of 1:1.46, are reacted in the reactor tube in the course of 6.5 hours.
2.48 moles of HF and 0.03 mole of HCl are determined in the wash water by titration. The composition of the crude condensate is determined by means of GC measurement:
CF3-CHClF 95.6%
CF2=CFC1 3.0%
CF3-CHC12 0.4%
CF3-CHF2 0.8%
CF3--CH2Cl ~ O.1%
CF3-CClF2 ~ 0.1%
No polymers were observed. The crude product trapped weighs 669 g; the yield of CF3-CHClF is thus 93.1% of theory, relative to the CF2=CFCl reacted. Further chracterization is carried out by means of IR and F and H NMR measurements.
Subsequent low-temperature distillation at -12.5 to -11C gives a fraction, having a weight of 612 g, of pure 2-chloro-1,1,1,2-tetrafluoroethane.
Comparison Example 3 Using the experimental apparatus of Example (1), !~ ~
~9~i345 ~illed wi-th the catalyst of Comparison Example ~1), a total of 354 g (3.04 moles) of CF2-CFCl and 92 ~ (4,6 moles~ of HFJ corresponding to a molar ratio CF2=CFCl:HF
~f 1:1.51, are passed through at an internal temperature of' 270 to c~0C, in the course of 4 hours.
1,19 moles of H~ and 0.33 mole of HCl are trapped in the wash water. The crude product has the following composition according to GC analysis:
CF3-CHClF 20.7 %
C~2=C~C1 ~ 0.05 %
(A~ CF3-CHC12 29 9 6 %
(B) CF3~CHF2 41.0 %
~C~ CF3-C~2C1 4-5 %
(D) CF~-C51F~ ~.2 %
1:~ The for~ation of the products (A) ~nd (B) or (C) and (~ can be explained by the various possibilities of disproportionation of the CF3-CHClF formed, the high proportion of product (B), namely pentafluoroethaneJ
arises as a result of chlcrinelfluorine exchange in the CF3-CHClF. This comparison example clearly shows 'he decisive influence of the reactor temperature on the composition of the reaction products.
Ex mple 7 For t,he hydrofluorination of bromotrifluoro ethylene, a gas mixture consis-ting of a total o~ 334 g (2.07 moles) of CF2=CFBr and 110 g (5.50 moles) of .
(molar ratio CF2=CFBr:HF of 1:2.66~ is reacted in the ; experimental apparatus of Exa~ple (1), filled with a catalyst as described in Ex~mple (1), at a temperature of - 2~ ~
165 to 176C~ in the course of 4 hours 3.44 moles of ~ are trapped in the wash water GC analysis of the crude product gives:
CF~-CHBrF 94.5 %
CF2=C~Br 3.0 %
CF2Br-C~2 1.1 %
CF3-CHF2 C, 1 . O %
356 g of orude product were collected in the trap. The yield of CF3-CHBrF is about 93~0 of theory, relatîve to the CF2=CFBr reacted. The purified crude product was characterized by IR and ~R measurements an~ also by determ~n~t-on of the boiling point of ~, to C.
Exam~le 8 1~ For the hydrofluorination of trifluoroiodo-ethylene, which can be prepared, for example, by dehydro-chiorinating 2-chloro-1,2,2-trifluoro-1-iodG-et11ane by known ~ethods, the experimental apparatus of ~xample ~
filled with the catalyst of Example (1~, is t~sed. A
to~al of 249 g (1.20 moles) of CF2=C~I and 46 g (2 3 moles) of HF (corresponding to a molar ratio CF2~CFI:HF of 1:1 9) are passed through the reactor at a te~perat re of 140 to 146GC, in the course of 4.5 hours.
1.03 ~oles of HF are determined in the wash water by titration. GC analysis of the crude condensate gives the following composition:
CF3-CHFI 93.5 %
- CF2-CFI 2.5 ~
CF3-CHF2 1.1 %
3~ 5 - CF2I-C~2 1.0 C:F2I-CF2I C 1 %
The crude product trapped weighs 268 g; the resultin~ yield o~ CF3-CHFI is thus abou~ 94~ of theory, rela-tive to the CF2-CFI reacted. The resulting main product was îurther characterized by IR, 19F and 1H NMR
measurements. The boiling point of the ethane is +39C¦l bar.
4.C5 moles of HF are determined in the wash water.
Gas chromatographic measurement of the crude product trappe~ gives the following data:
C~3-CHF~ 83.~ %
2 2 ~ 0 05 %
3.5 ~
~YCl-c4F8 3.3 %
~6F12 ~.5 %
FuL~tnermore, wllite solid residues consisting of polytetrafluoroethylene are observed on the cataly~t material, With a weight of 184 g for the condensate (crude product), the yield of pentafluoroethane in this comparison example is only about ~3% of theory, relative to the CF2=CF2 reacted. Although an increase in the reactor temperature leads to a quantitative conversion of ethylene, it gives rise to a higher proportion of by-products.
Exam~le 6 For the hydrofluorination of chlorotrifluoro-.
ethylene, which is easily obtainable in high purity as anindustrial intermediate, the chromium oxyEluoride catal~st used in Example (4) is initially introduced into the experimental apparatus of Example (1).
At an internal temperature oE 170 to 178C, a total of 605 g (5.19 moles) of CF2=CFCl and 152 g (7.6 moles) of HF, corresponding to a molar ratio CF2=CFCl:HF of 1:1.46, are reacted in the reactor tube in the course of 6.5 hours.
2.48 moles of HF and 0.03 mole of HCl are determined in the wash water by titration. The composition of the crude condensate is determined by means of GC measurement:
CF3-CHClF 95.6%
CF2=CFC1 3.0%
CF3-CHC12 0.4%
CF3-CHF2 0.8%
CF3--CH2Cl ~ O.1%
CF3-CClF2 ~ 0.1%
No polymers were observed. The crude product trapped weighs 669 g; the yield of CF3-CHClF is thus 93.1% of theory, relative to the CF2=CFCl reacted. Further chracterization is carried out by means of IR and F and H NMR measurements.
Subsequent low-temperature distillation at -12.5 to -11C gives a fraction, having a weight of 612 g, of pure 2-chloro-1,1,1,2-tetrafluoroethane.
Comparison Example 3 Using the experimental apparatus of Example (1), !~ ~
~9~i345 ~illed wi-th the catalyst of Comparison Example ~1), a total of 354 g (3.04 moles) of CF2-CFCl and 92 ~ (4,6 moles~ of HFJ corresponding to a molar ratio CF2=CFCl:HF
~f 1:1.51, are passed through at an internal temperature of' 270 to c~0C, in the course of 4 hours.
1,19 moles of H~ and 0.33 mole of HCl are trapped in the wash water. The crude product has the following composition according to GC analysis:
CF3-CHClF 20.7 %
C~2=C~C1 ~ 0.05 %
(A~ CF3-CHC12 29 9 6 %
(B) CF3~CHF2 41.0 %
~C~ CF3-C~2C1 4-5 %
(D) CF~-C51F~ ~.2 %
1:~ The for~ation of the products (A) ~nd (B) or (C) and (~ can be explained by the various possibilities of disproportionation of the CF3-CHClF formed, the high proportion of product (B), namely pentafluoroethaneJ
arises as a result of chlcrinelfluorine exchange in the CF3-CHClF. This comparison example clearly shows 'he decisive influence of the reactor temperature on the composition of the reaction products.
Ex mple 7 For t,he hydrofluorination of bromotrifluoro ethylene, a gas mixture consis-ting of a total o~ 334 g (2.07 moles) of CF2=CFBr and 110 g (5.50 moles) of .
(molar ratio CF2=CFBr:HF of 1:2.66~ is reacted in the ; experimental apparatus of Exa~ple (1), filled with a catalyst as described in Ex~mple (1), at a temperature of - 2~ ~
165 to 176C~ in the course of 4 hours 3.44 moles of ~ are trapped in the wash water GC analysis of the crude product gives:
CF~-CHBrF 94.5 %
CF2=C~Br 3.0 %
CF2Br-C~2 1.1 %
CF3-CHF2 C, 1 . O %
356 g of orude product were collected in the trap. The yield of CF3-CHBrF is about 93~0 of theory, relatîve to the CF2=CFBr reacted. The purified crude product was characterized by IR and ~R measurements an~ also by determ~n~t-on of the boiling point of ~, to C.
Exam~le 8 1~ For the hydrofluorination of trifluoroiodo-ethylene, which can be prepared, for example, by dehydro-chiorinating 2-chloro-1,2,2-trifluoro-1-iodG-et11ane by known ~ethods, the experimental apparatus of ~xample ~
filled with the catalyst of Example (1~, is t~sed. A
to~al of 249 g (1.20 moles) of CF2=C~I and 46 g (2 3 moles) of HF (corresponding to a molar ratio CF2~CFI:HF of 1:1 9) are passed through the reactor at a te~perat re of 140 to 146GC, in the course of 4.5 hours.
1.03 ~oles of HF are determined in the wash water by titration. GC analysis of the crude condensate gives the following composition:
CF3-CHFI 93.5 %
- CF2-CFI 2.5 ~
CF3-CHF2 1.1 %
3~ 5 - CF2I-C~2 1.0 C:F2I-CF2I C 1 %
The crude product trapped weighs 268 g; the resultin~ yield o~ CF3-CHFI is thus abou~ 94~ of theory, rela-tive to the CF2-CFI reacted. The resulting main product was îurther characterized by IR, 19F and 1H NMR
measurements. The boiling point of the ethane is +39C¦l bar.
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the preparation of very pure fluorine-containing ethanes of the general formula CF3-CHXY, in which X
denotes H or F and Y denotes H, F, C1, Br or iodine, from fluorine-containing ethylenes of the general formula CF2=CXY, in which X and Y have the meaning indicated above, with at least the equimolar amount of hydrogen fluoride, in the gas phase, which process comprises carrying out the reaction at temperatures of 20-200°C and in the presence of a chromium oxyfluoride catalyst which has been treated with hydrogen fluoride and elemental fluorine.
denotes H or F and Y denotes H, F, C1, Br or iodine, from fluorine-containing ethylenes of the general formula CF2=CXY, in which X and Y have the meaning indicated above, with at least the equimolar amount of hydrogen fluoride, in the gas phase, which process comprises carrying out the reaction at temperatures of 20-200°C and in the presence of a chromium oxyfluoride catalyst which has been treated with hydrogen fluoride and elemental fluorine.
2. A process as claimed in claim 1, wherein the chromium oxy-fluoride catalyst has been pre-treated with a gas mixture containing fluorine and hydrogen fluoride.
3. A process as claimed in claim 1 or 2 which comprises carrying out the reaction at reaction temperatures of 40°-190°C.
4. A process as claimed in claim 1 or 2 which comprises carrying out the reaction at reaction temperatures of 60°-180°C.
5. A process as claimed in claim 1 or 2 wherein the molar ratio of fluorine-containing ethylene to hydrogen fluoride is 1:1 to 1:3.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3009760.0 | 1980-03-14 | ||
| DE19803009760 DE3009760A1 (en) | 1980-03-14 | 1980-03-14 | METHOD FOR PRODUCING HIGH PURITY PARTLY FLUORINATED AETHANES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1196345A true CA1196345A (en) | 1985-11-05 |
Family
ID=6097165
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000372965A Expired CA1196345A (en) | 1980-03-14 | 1981-03-13 | Process for the preparation of very pure partially fluorinated ethanes |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0036123B1 (en) |
| JP (1) | JPS56142222A (en) |
| BR (1) | BR8101512A (en) |
| CA (1) | CA1196345A (en) |
| DE (2) | DE3009760A1 (en) |
| ES (1) | ES8201515A1 (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4766260A (en) * | 1987-07-07 | 1988-08-23 | E. I. Du Pont De Nemours And Company | Gas-phase fluorination process |
| WO1989011467A1 (en) * | 1988-05-23 | 1989-11-30 | E.I. Du Pont De Nemours And Company | Gas-phase fluorination process |
| US5026930A (en) * | 1987-08-13 | 1991-06-25 | E. I. Du Pont De Nemours And Company | Gas-phase fluorination process |
| US5334787A (en) * | 1991-05-06 | 1994-08-02 | E. I. Du Pont De Nemours And Company | Process for the manufacture of pentafluoroethane |
| US5382721A (en) * | 1992-06-09 | 1995-01-17 | Solvay (Societe Anonyme) | Process for the preparation of 1,1,1,2-tetrafluoroethane |
| US5399549A (en) * | 1991-05-06 | 1995-03-21 | E. I. Du Pont De Nemours And Company | Process for the manufacture of pentafluoroethane |
| US5463151A (en) * | 1989-07-12 | 1995-10-31 | Ausimont S.R.L. | Process for preparing 1,1,1,2-tetrafluoroethane |
| US5475167A (en) * | 1995-02-17 | 1995-12-12 | E. I. Du Pont De Nemours And Company | Process for the manufacture of pentafluoroethane |
| US5516947A (en) * | 1994-03-11 | 1996-05-14 | E. I. Du Pont De Nemours And Company | Process for converting chlorodifluoromethane and/or dichlorodifluoromethane |
| US5959166A (en) * | 1994-07-04 | 1999-09-28 | Korea Institute Of Science And Technology | Method for concurrently producing different hydrofluoro carbons |
| US5969199A (en) * | 1993-07-12 | 1999-10-19 | Solvay S.A. | Process for the addition of HF to halogenated alkenes |
| US7074973B2 (en) | 2002-08-22 | 2006-07-11 | E. I. Du Pont De Nemours And Company | Process for the preparation of 1,1,1,2,2-pentafluoroethane |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2004539B (en) * | 1977-09-20 | 1982-02-10 | Ici Ltd | Process for the manufacture of halogenated hydrocarbons |
| DE3323374A1 (en) * | 1983-06-29 | 1985-01-10 | Hoechst Ag, 6230 Frankfurt | CATALYSTS FOR FLUORATION AND / OR DISMUTATION REACTIONS OF HALOGEN HYDROCARBONS AND METHOD FOR THE PRODUCTION THEREOF |
| DE3676804D1 (en) * | 1986-01-22 | 1991-02-14 | Atochem North America | METHOD FOR CONVERTING A 1,1,1-TRIFLUORALKAN TO A 1,1-DIFLUORALKAN. |
| US4873381A (en) * | 1988-05-20 | 1989-10-10 | E. I. Du Pont De Nemours And Company | Hydrodehalogenation of CF3 CHClF in the presence of supported Pd |
| GB8824571D0 (en) * | 1988-10-20 | 1988-11-23 | Ici Plc | Chemical process |
| JP2748722B2 (en) * | 1991-05-24 | 1998-05-13 | ダイキン工業株式会社 | Method for producing chlorotrifluoroethylene |
| FR2694556B1 (en) * | 1992-08-05 | 1994-09-23 | Atochem Elf Sa | Process for the purification of 1,1,1,2-tetrafluoroethane. |
| CN1044802C (en) * | 1994-02-08 | 1999-08-25 | 浙江省化工研究院 | 1,1,1-trifluoroethane preparation by liquid-phase fluorization of 1,1,1-dichlorofluoroethane |
| CN1043571C (en) * | 1994-02-08 | 1999-06-09 | 浙江省化工研究院 | 1,1,1-trifluoroethane preparation by liquid-phase fluorization of unsym. vinylidene chloride |
| CN1044803C (en) * | 1994-02-08 | 1999-08-25 | 浙江省化工研究院 | 1,1,1-trifluoroethane preparation by gas-phase fluorization of 1,1,1-dichlorofluoroethane |
| FR2764883B1 (en) * | 1997-06-18 | 1999-07-16 | Atochem Elf Sa | PROCESS FOR THE MANUFACTURE OF HYDROFLUOROALCANES |
| US7247759B1 (en) * | 2006-01-04 | 2007-07-24 | Honeywell International Inc. | Fluorination reactor |
| US8158549B2 (en) * | 2009-09-04 | 2012-04-17 | Honeywell International Inc. | Catalysts for fluoroolefins hydrogenation |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4947158A (en) * | 1972-09-19 | 1974-05-07 | ||
| DE2702360A1 (en) * | 1977-01-21 | 1978-08-03 | Hoechst Ag | METHOD FOR REACTIVATING FLUORINATION CATALYSTS |
| DE2712732C2 (en) * | 1977-03-23 | 1986-03-13 | Hoechst Ag, 6230 Frankfurt | Process for the production of octafluoropropane |
| GB2004539B (en) * | 1977-09-20 | 1982-02-10 | Ici Ltd | Process for the manufacture of halogenated hydrocarbons |
-
1980
- 1980-03-14 DE DE19803009760 patent/DE3009760A1/en not_active Withdrawn
-
1981
- 1981-03-03 DE DE8181101502T patent/DE3160454D1/en not_active Expired
- 1981-03-03 EP EP81101502A patent/EP0036123B1/en not_active Expired
- 1981-03-06 ES ES500177A patent/ES8201515A1/en not_active Expired
- 1981-03-13 CA CA000372965A patent/CA1196345A/en not_active Expired
- 1981-03-13 BR BR8101512A patent/BR8101512A/en unknown
- 1981-03-13 JP JP3549281A patent/JPS56142222A/en active Granted
Cited By (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4766260A (en) * | 1987-07-07 | 1988-08-23 | E. I. Du Pont De Nemours And Company | Gas-phase fluorination process |
| US5026930A (en) * | 1987-08-13 | 1991-06-25 | E. I. Du Pont De Nemours And Company | Gas-phase fluorination process |
| WO1989011467A1 (en) * | 1988-05-23 | 1989-11-30 | E.I. Du Pont De Nemours And Company | Gas-phase fluorination process |
| US5463151A (en) * | 1989-07-12 | 1995-10-31 | Ausimont S.R.L. | Process for preparing 1,1,1,2-tetrafluoroethane |
| US6037508A (en) * | 1989-07-12 | 2000-03-14 | Ausimont S.P.A. | Process for preparing 1,1,1,2-tetrafluoroethane |
| US5880316A (en) * | 1989-07-12 | 1999-03-09 | Ausimont S.P.A. | Process for preparing 1,1,1,2-tetrafluoroethane |
| US5608125A (en) * | 1989-07-12 | 1997-03-04 | Ausimont S.P.A. | Process for preparing 1,1,1,2-tetrafluoroethane |
| EP0760356A3 (en) * | 1991-05-06 | 1997-03-19 | E.I. Du Pont De Nemours And Company | Process for the manufacture of pentafluoroethane |
| US5334787A (en) * | 1991-05-06 | 1994-08-02 | E. I. Du Pont De Nemours And Company | Process for the manufacture of pentafluoroethane |
| US5399549A (en) * | 1991-05-06 | 1995-03-21 | E. I. Du Pont De Nemours And Company | Process for the manufacture of pentafluoroethane |
| EP0760356A2 (en) | 1991-05-06 | 1997-03-05 | E.I. Du Pont De Nemours And Company | Process for the manufacture of pentafluoroethane |
| US5382721A (en) * | 1992-06-09 | 1995-01-17 | Solvay (Societe Anonyme) | Process for the preparation of 1,1,1,2-tetrafluoroethane |
| US5969199A (en) * | 1993-07-12 | 1999-10-19 | Solvay S.A. | Process for the addition of HF to halogenated alkenes |
| US5516947A (en) * | 1994-03-11 | 1996-05-14 | E. I. Du Pont De Nemours And Company | Process for converting chlorodifluoromethane and/or dichlorodifluoromethane |
| US5959166A (en) * | 1994-07-04 | 1999-09-28 | Korea Institute Of Science And Technology | Method for concurrently producing different hydrofluoro carbons |
| US5475167A (en) * | 1995-02-17 | 1995-12-12 | E. I. Du Pont De Nemours And Company | Process for the manufacture of pentafluoroethane |
| US7074973B2 (en) | 2002-08-22 | 2006-07-11 | E. I. Du Pont De Nemours And Company | Process for the preparation of 1,1,1,2,2-pentafluoroethane |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0036123A1 (en) | 1981-09-23 |
| EP0036123B1 (en) | 1983-06-22 |
| ES500177A0 (en) | 1982-01-16 |
| ES8201515A1 (en) | 1982-01-16 |
| DE3160454D1 (en) | 1983-07-28 |
| JPH0427218B2 (en) | 1992-05-11 |
| BR8101512A (en) | 1981-09-15 |
| DE3009760A1 (en) | 1981-09-24 |
| JPS56142222A (en) | 1981-11-06 |
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