CA1078855A - Process for the production of chlorofluorinated aliphatic ethers - Google Patents
Process for the production of chlorofluorinated aliphatic ethersInfo
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- CA1078855A CA1078855A CA267,965A CA267965A CA1078855A CA 1078855 A CA1078855 A CA 1078855A CA 267965 A CA267965 A CA 267965A CA 1078855 A CA1078855 A CA 1078855A
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Abstract
ABSTRACT OF THE DISCLOSURE
Chlorofluorinated aliphatic ethers may be effectively produced by an oxychlorofluorination process by reacting a gaseous mixture of a starting material selected from an aliphatic ether and a halogenated aliphatic ether in which the halogen atoms are selected from chlorine and flourine, or mixtures thereof, an oxygen-containing gas, a chlorinating agent selected from the group consisting of HC1 and C12 and mixtures thereof, and HF, in the presence of a Deacon catalyst supported by a stable, inert metal salt carrier.
Chlorofluorinated aliphatic ethers may be effectively produced by an oxychlorofluorination process by reacting a gaseous mixture of a starting material selected from an aliphatic ether and a halogenated aliphatic ether in which the halogen atoms are selected from chlorine and flourine, or mixtures thereof, an oxygen-containing gas, a chlorinating agent selected from the group consisting of HC1 and C12 and mixtures thereof, and HF, in the presence of a Deacon catalyst supported by a stable, inert metal salt carrier.
Description
7l38SS
INVEi~TION: PROCESS FOR T~E PRODUCTION OF CHLOROFLUORINATED
ALIPHATIC ETHERS
BACKGROUND OF T~E INVENTION
Chlorofluorinated aliphatic ethers are prepared by a t number of procedures generally involving two or more steps and the use of chlorine as a chlorinating agent which results in the production of large quantities of by-product ~Cl. For example, chlorofluorinated ethers may be prepared by chlorination of aliphatic ethers generally under free radical conditions, fol-lowed by fluorination with ~F or HF; by addition of a fluorinated olefin to an alcohol, followed by chlorination of the resulting ether; and by dehydration of a fluorinated glycol followed by chlorination of the resulting ether.
Because by-product hydrogen chloride does not have a steady market even after purification from small amounts of hydrogen fluoride contaminant, it is usually disposed of by dumping in rivers or in the ocean where permitted. The extra cost of this type of disposal is borne by the manufacturing operation.
Furthermore, in view of environmental considerations, it is probable that such disposals will be restricted or e~entually banned.
Chlorofluorinated acyclic hydrocarbons are commercially prepared by reacting chlorinated hydrocarbons with hydrogen fluoride in the presence of a fluorination catalyst. In such ~F
; reactions, for each mole of hydrogen fluoride reacted there is I one mole of hydrogen chloride liberated.
j Recently, a new process has been developed~for the production of chlorofluorinated aliphatic hydrocarbons which comprises reacting a mixture of a hydrocarbon and chlorine and hydrogen fluoride over a fluorination catalyst with a relatively large excess of recycled material consisting of underchlorinated and underfluorinated hydrocarbons. This :
.
- ~ O ~ ~S 5 process, which combines chlorination and ~luorination in one step, however, proauces more hydrogen chloride per unit weight of chlorofluorinated hydrocarbon than the standard commercial --process referred to above. It thus intensifies rather than alleviates the hydrogen chloride by-product problem.
In view of the above discussion, it is apparent that there is a need in the industry for new technology for the manufacture of chlorofluorinated compounds which does not suffer from the hydrogen chloride by-product problem.
The oxychlorination of hydrocarbons by a Deacon type reaction is well known in the art. This involves the chlorination of an alkane or a chloroalkane with chlorine or hydrogen chloride in the presence of an oxygen-containing gas such as air, and in the presence of a Deacon-type catalyst such as a metal halide impregnated on a suitable carrier. It is postulated that in such an oxychlorination reaction, hydrogen chloride is oxidized to chlorine and water and the chlorine thus produced then reacts with the organic material. In this manner, by-product hydrogen chloride is eliminated or at least ` 20 substantially minimized.
Vapor phase fluorination of chlorinated aliphatic hydrocarbons with and without the presence of a catalyst is also wèll known.
The combination of an oxychlorination reaction and a fluorination or chlorofluorination reaction into a simul-taneous one-step oxychlorofluorination process is suggested in British Patent 745,818, published March 7, 1956. Such a one-step process, if commercially feasible, would be of sub-stantial value not only in the avoidance of the HCl problem but also in the potential savings in capital equipment and energy expenditure.
- ' . - . ' -:
7~3855 The British patent is restricted to aliphatic hydro-carbon compounds and, in any event, unfortunately, the process as described is not commercially practical. Attempts to duplicate the catalyst systems described in the sritish patent have been unsuccessful. The CuC12 loading recommended in the patent exceeds the absorptive capacity of the carrier by more than two-fold. The excess CuC12 loading has been found to create serious operating problems such as plugging, ~ corrosion and erratic performance because of undue vaporization 10 and run-off of the CuC12. Another disadvantage found for such high CuC12 loading is that it deactivates the fluorination sites on the carrier thus causing a significant decrease in HF
conversions.
Others have experimented with fluorination systems for hydrocarbons containing HF, HCl, oxygen and a Deacon type catalyst, but no one to date has reported an effective system capable of supporting an efficient oxychlorofluorination reaction.
For example, U.S. Patent 3,476,817, issued Nov. 4, 1969, discloses a chlorofluorination reaction in which an aliphatic hydrocarbon is reacted with chlorine in the presence of HF, a Deacon type catalyst, and oxygen in an amount sufficient to improve the catalyst life. However, the oxygen according to this disclosure is not present in an amount sufficient to accomplish an ef~ective Deacon reaction and accordingly an efficient oxychlorofluorination reaction does not take place. U.S. Patent 2~578,913, issued Dec. 18, 1951, discloses the preparation of fluorinated aliphatic hydrocarbons by reacting a hydrocarbon with H~, in the presence of oxygen, a Deacon-type catalyst and a hydrogen halide promoter, such as HCl. However, the hydrogen halide promoter according to the disclosure is not present in an amount sufficient to ' - accomplish efficient chlorination and accordingly an efficient - . . ~ . ,. ~ .. . . . .
7885~i oxychlorofluorination reaction does not take place. In any e~ent none of the above-mentioned patents teach or suggest reactions of aliphatic ethers.
Accordingly, despite the potential advantages of an oxychlorofluorination process, such a process has not been commercialized. To the best of our knowledge, since publication of British Patent 745,818, no attempts have been reported in the literature to make this a viable process for aliphatic hydrocarbons, much less extend it to aliphatic ethers.
The reasons for this lack of interest and suspicion of impracticability of the oxychlorofluorination approach are many-fold. As mentioned above, the process as described in British Patent 745,818 cannot be duplicated and cannot be readily adapted for commercially practical results. Further, persons skilled in this art would, in considering commercial feasibility of an oxychlorofluorination process, fear the possibility of explosion and the flammability of hydrogen containing compounds in the oxygen-rich environment present. Also, the likelihood of hydrolysis of the products and/or underchlorinated and underfluorinated hydro-carbon intermediates is imminent since the reactions occur at relatively high temperatures in the presence of water. Another concern would be the possibility of substantial losses of start-ing materials, underchlorinated and underfluorinated hydrocarbon intermediates and products to combustion. Finally, it would be expected that the system would be unduly corrosive to known materials of construction due to the combined corrosive action of water, HCl and HF at the elevated temperatures required for the reaction.
GENERAL DESCRIPTIO~ OF THE INVENTION
Contrary to the expectations of those skilled in this art, an effective oxychlorofluorination process for the production .
~78~S~i of chlorofluorinated aliphatic ethers can be achieved, provided that certain critically defined conditions are observed and that a critically defined catalyst system is employed. Contrary to ; expectation, if such conditions are met, the reaction ean be readily controlled without undue danger from explosion and flammability, good yields of products can be obtained without undue loss due to hydrolysis or combustion reactions and, quite surprisingly, known materials of construction can be used for the apparatus with tolerable corrosion rates.
This may be aceomplished by reacting a gaseous mixture of a starting material selected from an a~iphatic ether and a halogenated aliphatic ether in which the halogen atoms are selected from chlorine and fluorine, or mixtures thereof, oxygen in an oxygen-containing gas, ~Cl or C12 and ~F, in the presence of a Deacon catalyst supportéd by a stable inert metal salt earrier, with the weight pereentage of eation in the Deaeon eatalyst ranging from about 0.6-20 based on the total cation content of the Deacon catalyst and metal salt carrier, at elevated temperatures and with a contact time of from about .l to 20 ~o seconds. Successful results depend on the combination of use of the Deaeon catalyst, with the cation content in the indicated weight percent range, and use of the relatively short contact times speeified.
The ehlorofluorinated aliphatic ether products are a well-known elass of compounds and are useful, inter alia, as liquid dieleetries (partieularly the higher chlorinated ethers~, inhalation anesthetics (particularly the higher fluorinated ethers), heat exehange fluids (particularly the higher halogenated ethers), and power fluids. Lower halogenated ethers may be eonverted to higher halogenated ethers as desired by conventional techniques.
.' ' ~
-5- ~ ~
``` 1~'71~855 :~ DETAILED DESCRIPTION OF THE INVENTION
It is theorized that in the oxychlorofluorination reaction, chlorination, oxidation and fluorination reactions all take place simultaneously. The chlorination reaction replaces one or more available hydrogen atoms in the starting material with chlorine to give a chlorinated product and HCl. In the presence of a suitable Deacon catalyst, as will be described in more detail hereafter, the HCl is oxidized back to chlorine which then is ;
available for further chlorination. Water is also formed. In the presence of a fluorination catalyst, or under suitable thermal conditions, the chlorinated products are fluorinated by HF to yield fluorinated products. It is not feasible to produce very highly fluorinated products in the oxychlorofluorination environ-ment. Depending on the conditions chosen, the final products are more or less partially fluorinated and may or may not contain hydrogen.
The aliphatic ether starting materials for the oxy-chlorofluorination reaction may be acyclic or cyclic. Preferably, the starting materials are saturated, contain only C, H and O
atoms and from 2 - 10 carbon atoms an~, still preferably, from 2 -5 carbon atoms. Illustrative suitable aliphatic ether starting materials include methyl ether, ethyl ether, n-butyl ether, isopropyl ether, methyl ethyl ether, n-amyl ether, sec-butyl n-hexyl ether, ethylene oxide, propylene oxide, 1,4-dioxane, tetrahydrofuran, pyran, 2,4-dioxahexane and 2,4,6-trioxaoctane.
,i The preferred aliphatic ether starting materials are ethyl ether and methyl ethyl ether.
The halogenated aliphatic ether class of starting materials are those aliphatic ether starting materials as described above in which one or more hydrogen atoms are replaced with halogen atoms selected from fluorine and chlorine. These ~` .
:.
~LC3'78855 materials must contain at least one hydrogen atom. The halogen atoms may be all chlorine, all fluorine, or both. Preferably, these starting materials contain more atoms of hydrogen than halogen. Still preferably, the number of fluorine atoms in the molecules does not exceed more than one for each carbon atom present. Illustrative suitable starting materials of this class are ~,~ l-dichlorodiethyl ether, ~ -chloro, o~l-fluorodipent ether, and 2,3-dichlorodioxane.
The "oxygen-containing gas" refers to oxygen or an oxygen-containing mixture with gases whlch are not reactive under the process conditions employed. Examples of suitable oxygen-containing gas mixtures include oxygen enriched air, air mixed with inert gases and mixtures of oxygen, air and inert gases.
The theoretical ~uantity of oxygen in an oxygen-containing gas required for the oxychlorination reaction is the stoichiometric amount required to convert C-H bonds to C-Cl bonds in accordance with the following formula:
C-H ~ ~Cl + 1/2 2 ~ C-Cl + H2O
In other words, .50 mole oxygen for each C-H bond in the starting material desired to be reacted is stoichiometrically required. An 80~ deficiency may be employed with satisfactory results, or at least .10 mole oxygen for each C-H bond in the starting material. Depending on the nature of the final products desired, it may be preferred to employ at least 0.25, preferably at least 0.50 mole, and, still preferably, up to about a 50~ excess, or .75 mole oxygen for each C-H bond in the starting material.
Large excesses of oxygen will not deleteriously affect the ;
reaction except for the possibility of creating a flammability problem.
HCl or chlorine may be used as the chlorine source for the oxychlorofluorination reaction. If HCl is used, it may be supplied from an outside source or, it may be prepared LC17~85S
in situ, by the reaction of the HF ~eed with a chlorine-con-taining aliphatic ether starting material if present.
The theoretical quantity of HCl or C12 used in the reaction is the stoichiometric amount required for the desired hydrogen replacement in the starting material. This amounts to 1 mole of HCl or equivalent amount of C12 (.5 mole) for each C-H bond desired to be reacted in the starting material. A 90%
deficiency of HCl or equivalent amount of C12, or .10 mole HCl or equivalent amount of C12, for each C-H bond present in the starting material, may be employed with good results, particularly if it is desired to favor the production of lower chlorinated pro-ducts. Depending on the nature of the final product desired, it may be preferred to employ at least 0.25, preferably at least 0.50, and, still preferably, at least 0.75 mole HCl or equivalent amount of C12 for each C-H bond present in the starting material. Excess HCl or C12 may be used to insure maximum conversions to the highly chlorinated products without deleterious effects. If it is desired to preserve some C-H bonds in the final product, a somewhat greater deficiency of HCl or chlorine should be employed, but in no event less than 2 0 moles of HCl or equivalent amount of C12 for each mole of starting material.
In the case that HC1 is charged, such would be converted to chlorine by the Deacon reaction and chlorine would then be the active chlorinating agent.
The quantity of HF to be employed is equal to at least one mole of hydrogen fluoride per mole of starting material for ~ every fluorine atom desired in the end product which is to be - achieved by the fluorination reaction. The oxychlorofluorination environment does not favor the formation of very highly fluori-nated products. It is not generally feasible to obtain substan-tially greater than 1.0-104 fluorine atoms per each carbon atom ~ ~ .
,~ ~,. .
`~ ~Ci 7~35~
in the product. Large excesses of hydrogen fluoride may be used, however, without adversely a~fecting the reaction and may in fact be advantageous in assisting in control over reaction temperatures.
The Deacon catalysts are the oxychlorination or Deacon-type reaction catalysts which are well known in the art. The most active catalysts of this type are the oxides and halides of multivalent metals having variable valence states. Illustra-tive of such metals are Cu, Sn, Ni, Rh, Fe, V, Mn, Co, Pb, Cd, Hg, Pb, Ce and Cr. The preferred metal is Cu. The preferred forms of these metals are the halides, especially the chlorides.
Illustrative suitable Deacon catalysts are CuC12, Cu20, CuO, FeCl2, FeCl3, FeO, Fe203, Cu2C12, Cr203, CrCl3, C 2' 2' MnO2, SnCl2, NiBr2, RhC13, VC13, CoO2, PdC12, Cd(NO3)2, HgBr2, PbCl2 and CetNO3)3. The preferred Deacon catalyst is copper chloride. Mixtures of Deacon catalysts may be employed. Other metal salts such as alkali or alkaline earth metal chlorides may be combined with the Deacon catalyst. These may serve to promote the Deacon reaction, promote the fluorination and chlorination reactions or inhibit combustion and hydrolysis reactions. Illustra- -
INVEi~TION: PROCESS FOR T~E PRODUCTION OF CHLOROFLUORINATED
ALIPHATIC ETHERS
BACKGROUND OF T~E INVENTION
Chlorofluorinated aliphatic ethers are prepared by a t number of procedures generally involving two or more steps and the use of chlorine as a chlorinating agent which results in the production of large quantities of by-product ~Cl. For example, chlorofluorinated ethers may be prepared by chlorination of aliphatic ethers generally under free radical conditions, fol-lowed by fluorination with ~F or HF; by addition of a fluorinated olefin to an alcohol, followed by chlorination of the resulting ether; and by dehydration of a fluorinated glycol followed by chlorination of the resulting ether.
Because by-product hydrogen chloride does not have a steady market even after purification from small amounts of hydrogen fluoride contaminant, it is usually disposed of by dumping in rivers or in the ocean where permitted. The extra cost of this type of disposal is borne by the manufacturing operation.
Furthermore, in view of environmental considerations, it is probable that such disposals will be restricted or e~entually banned.
Chlorofluorinated acyclic hydrocarbons are commercially prepared by reacting chlorinated hydrocarbons with hydrogen fluoride in the presence of a fluorination catalyst. In such ~F
; reactions, for each mole of hydrogen fluoride reacted there is I one mole of hydrogen chloride liberated.
j Recently, a new process has been developed~for the production of chlorofluorinated aliphatic hydrocarbons which comprises reacting a mixture of a hydrocarbon and chlorine and hydrogen fluoride over a fluorination catalyst with a relatively large excess of recycled material consisting of underchlorinated and underfluorinated hydrocarbons. This :
.
- ~ O ~ ~S 5 process, which combines chlorination and ~luorination in one step, however, proauces more hydrogen chloride per unit weight of chlorofluorinated hydrocarbon than the standard commercial --process referred to above. It thus intensifies rather than alleviates the hydrogen chloride by-product problem.
In view of the above discussion, it is apparent that there is a need in the industry for new technology for the manufacture of chlorofluorinated compounds which does not suffer from the hydrogen chloride by-product problem.
The oxychlorination of hydrocarbons by a Deacon type reaction is well known in the art. This involves the chlorination of an alkane or a chloroalkane with chlorine or hydrogen chloride in the presence of an oxygen-containing gas such as air, and in the presence of a Deacon-type catalyst such as a metal halide impregnated on a suitable carrier. It is postulated that in such an oxychlorination reaction, hydrogen chloride is oxidized to chlorine and water and the chlorine thus produced then reacts with the organic material. In this manner, by-product hydrogen chloride is eliminated or at least ` 20 substantially minimized.
Vapor phase fluorination of chlorinated aliphatic hydrocarbons with and without the presence of a catalyst is also wèll known.
The combination of an oxychlorination reaction and a fluorination or chlorofluorination reaction into a simul-taneous one-step oxychlorofluorination process is suggested in British Patent 745,818, published March 7, 1956. Such a one-step process, if commercially feasible, would be of sub-stantial value not only in the avoidance of the HCl problem but also in the potential savings in capital equipment and energy expenditure.
- ' . - . ' -:
7~3855 The British patent is restricted to aliphatic hydro-carbon compounds and, in any event, unfortunately, the process as described is not commercially practical. Attempts to duplicate the catalyst systems described in the sritish patent have been unsuccessful. The CuC12 loading recommended in the patent exceeds the absorptive capacity of the carrier by more than two-fold. The excess CuC12 loading has been found to create serious operating problems such as plugging, ~ corrosion and erratic performance because of undue vaporization 10 and run-off of the CuC12. Another disadvantage found for such high CuC12 loading is that it deactivates the fluorination sites on the carrier thus causing a significant decrease in HF
conversions.
Others have experimented with fluorination systems for hydrocarbons containing HF, HCl, oxygen and a Deacon type catalyst, but no one to date has reported an effective system capable of supporting an efficient oxychlorofluorination reaction.
For example, U.S. Patent 3,476,817, issued Nov. 4, 1969, discloses a chlorofluorination reaction in which an aliphatic hydrocarbon is reacted with chlorine in the presence of HF, a Deacon type catalyst, and oxygen in an amount sufficient to improve the catalyst life. However, the oxygen according to this disclosure is not present in an amount sufficient to accomplish an ef~ective Deacon reaction and accordingly an efficient oxychlorofluorination reaction does not take place. U.S. Patent 2~578,913, issued Dec. 18, 1951, discloses the preparation of fluorinated aliphatic hydrocarbons by reacting a hydrocarbon with H~, in the presence of oxygen, a Deacon-type catalyst and a hydrogen halide promoter, such as HCl. However, the hydrogen halide promoter according to the disclosure is not present in an amount sufficient to ' - accomplish efficient chlorination and accordingly an efficient - . . ~ . ,. ~ .. . . . .
7885~i oxychlorofluorination reaction does not take place. In any e~ent none of the above-mentioned patents teach or suggest reactions of aliphatic ethers.
Accordingly, despite the potential advantages of an oxychlorofluorination process, such a process has not been commercialized. To the best of our knowledge, since publication of British Patent 745,818, no attempts have been reported in the literature to make this a viable process for aliphatic hydrocarbons, much less extend it to aliphatic ethers.
The reasons for this lack of interest and suspicion of impracticability of the oxychlorofluorination approach are many-fold. As mentioned above, the process as described in British Patent 745,818 cannot be duplicated and cannot be readily adapted for commercially practical results. Further, persons skilled in this art would, in considering commercial feasibility of an oxychlorofluorination process, fear the possibility of explosion and the flammability of hydrogen containing compounds in the oxygen-rich environment present. Also, the likelihood of hydrolysis of the products and/or underchlorinated and underfluorinated hydro-carbon intermediates is imminent since the reactions occur at relatively high temperatures in the presence of water. Another concern would be the possibility of substantial losses of start-ing materials, underchlorinated and underfluorinated hydrocarbon intermediates and products to combustion. Finally, it would be expected that the system would be unduly corrosive to known materials of construction due to the combined corrosive action of water, HCl and HF at the elevated temperatures required for the reaction.
GENERAL DESCRIPTIO~ OF THE INVENTION
Contrary to the expectations of those skilled in this art, an effective oxychlorofluorination process for the production .
~78~S~i of chlorofluorinated aliphatic ethers can be achieved, provided that certain critically defined conditions are observed and that a critically defined catalyst system is employed. Contrary to ; expectation, if such conditions are met, the reaction ean be readily controlled without undue danger from explosion and flammability, good yields of products can be obtained without undue loss due to hydrolysis or combustion reactions and, quite surprisingly, known materials of construction can be used for the apparatus with tolerable corrosion rates.
This may be aceomplished by reacting a gaseous mixture of a starting material selected from an a~iphatic ether and a halogenated aliphatic ether in which the halogen atoms are selected from chlorine and fluorine, or mixtures thereof, oxygen in an oxygen-containing gas, ~Cl or C12 and ~F, in the presence of a Deacon catalyst supportéd by a stable inert metal salt earrier, with the weight pereentage of eation in the Deaeon eatalyst ranging from about 0.6-20 based on the total cation content of the Deacon catalyst and metal salt carrier, at elevated temperatures and with a contact time of from about .l to 20 ~o seconds. Successful results depend on the combination of use of the Deaeon catalyst, with the cation content in the indicated weight percent range, and use of the relatively short contact times speeified.
The ehlorofluorinated aliphatic ether products are a well-known elass of compounds and are useful, inter alia, as liquid dieleetries (partieularly the higher chlorinated ethers~, inhalation anesthetics (particularly the higher fluorinated ethers), heat exehange fluids (particularly the higher halogenated ethers), and power fluids. Lower halogenated ethers may be eonverted to higher halogenated ethers as desired by conventional techniques.
.' ' ~
-5- ~ ~
``` 1~'71~855 :~ DETAILED DESCRIPTION OF THE INVENTION
It is theorized that in the oxychlorofluorination reaction, chlorination, oxidation and fluorination reactions all take place simultaneously. The chlorination reaction replaces one or more available hydrogen atoms in the starting material with chlorine to give a chlorinated product and HCl. In the presence of a suitable Deacon catalyst, as will be described in more detail hereafter, the HCl is oxidized back to chlorine which then is ;
available for further chlorination. Water is also formed. In the presence of a fluorination catalyst, or under suitable thermal conditions, the chlorinated products are fluorinated by HF to yield fluorinated products. It is not feasible to produce very highly fluorinated products in the oxychlorofluorination environ-ment. Depending on the conditions chosen, the final products are more or less partially fluorinated and may or may not contain hydrogen.
The aliphatic ether starting materials for the oxy-chlorofluorination reaction may be acyclic or cyclic. Preferably, the starting materials are saturated, contain only C, H and O
atoms and from 2 - 10 carbon atoms an~, still preferably, from 2 -5 carbon atoms. Illustrative suitable aliphatic ether starting materials include methyl ether, ethyl ether, n-butyl ether, isopropyl ether, methyl ethyl ether, n-amyl ether, sec-butyl n-hexyl ether, ethylene oxide, propylene oxide, 1,4-dioxane, tetrahydrofuran, pyran, 2,4-dioxahexane and 2,4,6-trioxaoctane.
,i The preferred aliphatic ether starting materials are ethyl ether and methyl ethyl ether.
The halogenated aliphatic ether class of starting materials are those aliphatic ether starting materials as described above in which one or more hydrogen atoms are replaced with halogen atoms selected from fluorine and chlorine. These ~` .
:.
~LC3'78855 materials must contain at least one hydrogen atom. The halogen atoms may be all chlorine, all fluorine, or both. Preferably, these starting materials contain more atoms of hydrogen than halogen. Still preferably, the number of fluorine atoms in the molecules does not exceed more than one for each carbon atom present. Illustrative suitable starting materials of this class are ~,~ l-dichlorodiethyl ether, ~ -chloro, o~l-fluorodipent ether, and 2,3-dichlorodioxane.
The "oxygen-containing gas" refers to oxygen or an oxygen-containing mixture with gases whlch are not reactive under the process conditions employed. Examples of suitable oxygen-containing gas mixtures include oxygen enriched air, air mixed with inert gases and mixtures of oxygen, air and inert gases.
The theoretical ~uantity of oxygen in an oxygen-containing gas required for the oxychlorination reaction is the stoichiometric amount required to convert C-H bonds to C-Cl bonds in accordance with the following formula:
C-H ~ ~Cl + 1/2 2 ~ C-Cl + H2O
In other words, .50 mole oxygen for each C-H bond in the starting material desired to be reacted is stoichiometrically required. An 80~ deficiency may be employed with satisfactory results, or at least .10 mole oxygen for each C-H bond in the starting material. Depending on the nature of the final products desired, it may be preferred to employ at least 0.25, preferably at least 0.50 mole, and, still preferably, up to about a 50~ excess, or .75 mole oxygen for each C-H bond in the starting material.
Large excesses of oxygen will not deleteriously affect the ;
reaction except for the possibility of creating a flammability problem.
HCl or chlorine may be used as the chlorine source for the oxychlorofluorination reaction. If HCl is used, it may be supplied from an outside source or, it may be prepared LC17~85S
in situ, by the reaction of the HF ~eed with a chlorine-con-taining aliphatic ether starting material if present.
The theoretical quantity of HCl or C12 used in the reaction is the stoichiometric amount required for the desired hydrogen replacement in the starting material. This amounts to 1 mole of HCl or equivalent amount of C12 (.5 mole) for each C-H bond desired to be reacted in the starting material. A 90%
deficiency of HCl or equivalent amount of C12, or .10 mole HCl or equivalent amount of C12, for each C-H bond present in the starting material, may be employed with good results, particularly if it is desired to favor the production of lower chlorinated pro-ducts. Depending on the nature of the final product desired, it may be preferred to employ at least 0.25, preferably at least 0.50, and, still preferably, at least 0.75 mole HCl or equivalent amount of C12 for each C-H bond present in the starting material. Excess HCl or C12 may be used to insure maximum conversions to the highly chlorinated products without deleterious effects. If it is desired to preserve some C-H bonds in the final product, a somewhat greater deficiency of HCl or chlorine should be employed, but in no event less than 2 0 moles of HCl or equivalent amount of C12 for each mole of starting material.
In the case that HC1 is charged, such would be converted to chlorine by the Deacon reaction and chlorine would then be the active chlorinating agent.
The quantity of HF to be employed is equal to at least one mole of hydrogen fluoride per mole of starting material for ~ every fluorine atom desired in the end product which is to be - achieved by the fluorination reaction. The oxychlorofluorination environment does not favor the formation of very highly fluori-nated products. It is not generally feasible to obtain substan-tially greater than 1.0-104 fluorine atoms per each carbon atom ~ ~ .
,~ ~,. .
`~ ~Ci 7~35~
in the product. Large excesses of hydrogen fluoride may be used, however, without adversely a~fecting the reaction and may in fact be advantageous in assisting in control over reaction temperatures.
The Deacon catalysts are the oxychlorination or Deacon-type reaction catalysts which are well known in the art. The most active catalysts of this type are the oxides and halides of multivalent metals having variable valence states. Illustra-tive of such metals are Cu, Sn, Ni, Rh, Fe, V, Mn, Co, Pb, Cd, Hg, Pb, Ce and Cr. The preferred metal is Cu. The preferred forms of these metals are the halides, especially the chlorides.
Illustrative suitable Deacon catalysts are CuC12, Cu20, CuO, FeCl2, FeCl3, FeO, Fe203, Cu2C12, Cr203, CrCl3, C 2' 2' MnO2, SnCl2, NiBr2, RhC13, VC13, CoO2, PdC12, Cd(NO3)2, HgBr2, PbCl2 and CetNO3)3. The preferred Deacon catalyst is copper chloride. Mixtures of Deacon catalysts may be employed. Other metal salts such as alkali or alkaline earth metal chlorides may be combined with the Deacon catalyst. These may serve to promote the Deacon reaction, promote the fluorination and chlorination reactions or inhibit combustion and hydrolysis reactions. Illustra- -
2~ tive suitable metal salts of this type are the chlorides of Li, Na, K, Rb, La, Th, Ce, Ta and Cs. In order to achieve a signifi-cant amount of promotion, it is desirable to use at least .5 mole of the metal salt promoter per mole of Deacon catalyst. Large excesses of the metal salt promoter will not deleteriously affect the reaction. Generally, it is preferable to employ from about 1-2 moles of metal salt promoter per mole of Deacon catalyst and, still preferably, about l mole of metal salt promoter per mole of Deacon catalyst.
The Deacon catalyst is used in combination with a stable, inert metal salt carrier.
By "stable" is intended to mean that the carrier is _g_ :
7i3~3~;5 dimensionally and physically skable in the sense that when used in a fixed bed reactor, no more than 20% by weight of the carrier crumbles or converts to a powder from its original granular or pelleted form after 500 hours of operation, or when used in a fluidized bed reactor, the carrier does not undergo erosion or agglomeration to the extent that the particle size distribution changes sufficiently to adversely affect the operation of the fluidized bed. Acceptable particle size distributions for fluid-ized bed reactions are set by standard engineering practice well known to persons skilled in the art. It is also a characteristic of being "stable" for the purpose of this description that the carrier is substantially non-volatile and non-melting at tempera-tures up to about 550C.
By "inert" is intended to mean that which is or becomes substantially non-reactive with the organic starting materials, HF, HCl if used or prepared in situ, C12 and 2 Some minor reac-tion with the aforementioned materials can be tolerated provided that such reaction does not adversely affect the oxychlorofluori-nation reaction or the catalyst life. Alumina (A12O3) is not con-sidered to be inert within this definition because it undergoessubstantial reaction with HF under oxychlorofluorination condi-tions. An example of a permissible minor reaction is the forma-tlon of small amounts of fluorides and/or oxyfluorides which will not further react with the aforementioned materialsO The term "inert" is not intended to exclude catalytically active materials provided such materials satisfy the other requirements for being inert as described above. For example, a material satisfying the requirements for the stable, inert, metal salt carrier as defined herein, may also function as a ~luorination or Deacon catalyst, as defined herein.
. ~ .
, ~ 7!31~5~
A preferred embodiment of the stable inert metal salt carrier are those carriers which are fluorination catalysts, such as A1~3.
A variety of metal salts meet these criteria of being stable and inert including, for example, certain chlorides, fluorides, oxyhalides, or oxides and admixtures thereof of Al, Mg, Ca, sa, V, Th, Sr, Co, Ni, Cd, Pb, Cr and Fe, or combinations thereof. Illustrative suitable metal salts are AlF3, MgF2, CaF2, BaF2, V2O3, ThF4, SrF2, CoF2, NiF2, CdF2, PbO, CrF3 and Fe2O3.
The preferred anion for the metal salt carriers is fluoride. The preferred cation is aluminum and the preferred support material i5 AlF3. Depending on the results desired, choice of the stable, inert metal salt support may have a substantial influence on the particular oxychlorofluorination reaction involved. As indicated above, the support may catalyze the fluorination reaction. It may also influence the degree of Deacon reaction obtained, the degree to which the HF reactant is utilized and the loss of start-ing materials to combustion and hydrolysis.
The metal salt used as the support may be pre-pared beforehand or formed in situ during the reaction. For example, the Deacon catalyst may be impregnated on alumina (aluminum oxide). Under oxychlorofluorination conditions, particularly exposure to EIF at elevated temperatures, the sur-face of the alumina is converted to AlF3. The process aspects of this invention employing such catalysts are considered to be part of the invention herein, although this is not a preferred mode of operation. Preferably, the support throughout the oxy-chlorofluorination reaction comprises at least about 80~ by weight of the metal salt and, still preferably, at least about 90% by weight of the metal salt. German Patent No.
2,114,457 discloses a number of chlorofluorination catalysts , .
".
'' : ,: ', ' ' ~ . :
,~ , . ..
~ ~8~5i5 including CuCl2 impregnated on a support such as aluminum oxide in which the catalyst loading is between about l-10 weight percent metal based on the total weight of the catalyst salts and the support material. It is disclosed that during the chlorofluorination reaction the surface of the aluminum oxide is presumed to be converted to AlF3, however, it is not believed possible to achieve at least 80% weight pe~cent AlF3 in this manner, principally since the normal chlorofluorination reaction temperatures are not high enough for optimum con-versions of aluminum oxide to AlF3.
The preferred support material, AlF3, may be prepared by fluorinating alumina with HF at elevated tempera-tures. The alumina starting material for the supports is commercially available. Either the commercially available alpha or gamma aluminas may be employed; however, it has been founa that a superior carrier is formed by fluorination of gamma alumina. The aluminas may be readily fluorinated in their commercially available form as granules or pellets with anhydrous HF diluted with nitrogen at temperatures ranging from about 200-650C. It is preferred to conduct a sub-stantial portion of the fluorination at the upper portion of this range, preferably at about 550-650C. Most preferred, in fact, is to maintain the temperature at about 650C. for the entire fluorination. At low fluorination temperatures a mixture of alpha and gamma forms of AlF3 is obtained. At high fluorination temperatures the alpha form of AlF3 is ob-tained. It has been found that the alpha form of AlF3 is superior to the gamma form for oxychlorofluorination purposes.
The gamma form of AlF3 may also be prepared by the fluorina-tion of AlCl3 or the thermal decomposition of (NH4)3AlF6. The alpha form may also be readily prepared by reacting Al(OH~3 ,.
. ~ :, : ~ ' '' 3L~78~55 with HF.
It is essential according to the invention process that the weight percentage of cation in the Deacon catalyst during the oxychlorofluorination reaction be in the range of 0.6-20, preferably 1-16 and, still preferably, 2-8, based on the total cation content of the Deacon catalyst and the stable, inert metal salt carrier. For the purpose of deter-mining the weight percentage of cation in the Deacon catalyst, the presence of cations in any additional metal salt promoters which are not themselves Deacon catalysts, shall be ignored.
It is within the scope of this invention to charge a supported ---Deacon catalyst to the oxychlorofluorination reaction in which the cation content of the Deacon catalyst exceeds the maximum 20 weight percent level defined herein and subsequently during the course of the o~ychlorofluorination reaction to permit the Deacon catalyst cation content to fall to within the claimed limits. Use of a concentration of Deacon catalyst substantially in excess of the above-described 20 weight percent limitation on cation concentration, however, results in an unstable catalyst with low activity and which creates corrosion problems. Such catalysts cannot be fluidized if desired and cannot be reused.
For example, in the oxychlorofluorination reaction dis- -closed in ~ritish Patent 745,818, it is disclosed that 31 weight percent CuC12 be impregnated into AlF3/NaCl. On the basis of cation sontent of the Deacon catalyst based on the total cation content of the Deacon catalyst and the support, this amounts to 38.6 weight percent. Attempts to duplicate this catalyst have failed. It has been found that such 31 weight percent CuC12 loading exceeds the absorptive capacity of the carrier by more than two-fold. Only 23 weight percent CuC12 was able to be impregnated. When this 23 weight percent CuC12 was tested in an oxychlorofluorination ' . ~ , .; . ,: .:
7l~
reaction, there was considerab]e run-off of CuC12 so that only about 14 weight percent CuC12 loading was actually achieved. This run-off and the vaporization of the excess CuC12 caused severe operating problems, such as plugging and erratic performance. The excess CuC12 also created a corrosion problem with the metallic reactor walls. A low catalytic activity was also noted with this catalyst and this was attributed to be caused by the deactivation of fluorination sites on the carrier by the excess CuC12, thus decreasing HF conversions.
Any conventional technique may be employed for placing the catalyst material on the metal salt carrier. The object is to accomplish the most uniform distribution of catalytic material on the carrier as is possible. By way of illustration the catalytic material may be sprayed upon the support particles in mixing ; devices, a solution containing the catalyst may be sprayed into a fluidized bed of the carrier particles, or the carrier particles may be simply immersed in a solution containing the catalyst material followed by evaporation of the solution.
Reaction temperatures are elevated and may vary depending on the starting material chosen, the catalyst and other factors. Generally, reaction temperatures should be maintained between about 300-600C., preferably between about 350-550C. If the reaction temperature is excessive in a particular environment/ then the combustion of the aliphatic ethers or halogenated aliphatic ehters or the hydrolysis of the halo-` genated aliphatic ethers may become excessive. If the reaction temperature is unduly low, there will be a decline in the chlori-nation and fluorination reactions. The ideal reaction temperature for a particular oxychlorofluorination environment will depend on the starting materials chosen, the catalyst and other factors, as can readily be determined by those skilled in the art assisted by 8S~
the considerations discussed above.
Contact time is critical. Contrary to the disclosureof sritish Patent 745,818 which suggests a contact time of approximately 24 seconds, it is essential not to employ a contact time over about 20 seconds. If contact times substantially above 20 seconds are employed, substantial losses to combustion and to hydrolysis occur and the production capacity per unit volume of catalyst decreases. For example, with the preferred catalyst system of CuC12 on AlF3, at approximately 24 seconds contact time, production of CO2 is 4-5 -times greater than at a contact time of approximately 2-6 seconds. If the contact times are too low, satisfactory conversion rates cannot be obtained. ~ccording- ; -ly, contact times must be maintained between about .1 to 20 seconds, preferably between about 2-12 seconds. For fixed bed ;
operation, the preferred contact time is from about 1-18 seconds and, still preferably, from about 2-6 seconds. For dynamic or fluidized bed operation, the preferred contact time is between about 3-20 seconds and, still preferably, from about 6-12 seconds.
By "contact" time (C.T.) is intended to mean essentially the residence time that the feed materials contact each other in the presence of the catalyst, or, more precisely in the case of a fixed bed design (X):
C.T.X. (seconds) =
Catalyst Volume (ml) x 273 K x 3600/sec/hr x pressure (atm) 22,~00 ml x reactor temperature ( K) x moles (reactants)/hr.
In the case of a fluid bed design (L):
C.T.L. (seconds)=superficial Gas VelocitY (ft-/sec)*
Pressure is not a critical consideration as the reactions described herein may be conducted under atmospheric *Volume of gas/sec. (ft.3/sec) cross-sectional area (ft.~) of reactor ,.
pressure or superatmospheric pressures. In the preferred ; embodiment, superatmospheric pressures are employed, preferably up to about 200 p.s.i.g. and, still pre~erably, from about 20-75 p.s.i.g.
The chlorination, fluorination and Deacon reactions are highly exothermic. It is desirable to control the exothermic heat of such reaction to avoid pyrolysis, carboni-zation, combustion and other undesirable side reactions.
Mechanical cooling means may be employed to control the exotherm, such as cooling jackets, cooling spray, cooling coils or other suitable heat exchange means. Another way to control the exotherm is by diluting the catalyst with an inert, solid material such as fused alumina.
Another way to control the exotherm is by adding an inert gas to the reaction gas stream. By~"inert gas" is intended to mean an organic or inorganic gas which is inert to reaction with the organic reactants and with chlorine, oxygenj water or HC1, but not necessarily inert to reaction with hydrogen fluoride. Illustrative suitable inert inorganic gas diluents are nitrogen, hydrogen chloride, helium and argon.
Illustrative suitable inert organic gas diluents are carbon tetra-chloride, carbon tetrafluoride and hexachloroethane.
The amount of diluent to be used is that which is needed to control the reaction temperature oE the particular reaction involved. This will depend on the amount of chlorina-tion taking place and the nature of the diluent used. The preferred amount of diluent may be readily determined by those skilled in the art. Generally, the molar ratio of the diluent to the carbon containing feed materials ranges from about .5-4:1, with the preferred ratio ranging from about 1-2:1. At the end of the reaction, the diluent may either be recycled or discarded.
"` ~LC~78855 The preferred way to control the exotherm is by recycling one or more halogenated aliphatic ethers ~rom the product mixture to the reaction mixture. The recycled halogenated aliphatic ethers may be partially chlorinated reaction products, completely chlorinated reaction products, and/or under-fluorinated reaction products. The recycled halogenated aliphatic ethers may be inert to Eurther reaction or they may be subject to further reaction. If a recycle medium is employed, about 1-6:1 molar ratio of recycled halogenated aliphatic ether to aliphatic ether starting material should be employed, with a preferred molar ratio of about 2-4:1. There is nothing critical about the upper limit for the concentration of the recycled products, except from the standpoint of unit capacity and economy.
In addition to the advantage of providing control over reaction exotherm, use of a recycle affords the advantages of higher utilization of HF, attainment of higher yields of the more fluorinated products, a more efficient use of oxygen, less combustion, higher conversion of reactants and a means of control over final product distribution. A high HF utili-zation is particularly important since recovery of s~bstantial amounts of unreacted HF for recycling is expensive and adds substantially to manufacturing costs. Recycle with underfluori-nated products results in further fluorination of the under-fluorinated recycle material and thus provides control over the desired product distribution in the final product mix.
Simple experimentation with the make-up and quantity of the I recycle in a particular environment will permit ready determina-tion of optimum HF utilization conditions and optimum conditions for achieving the product distribution desired.
.
~Q78BSS
Attainment of the above-described advantageous results with a recycle was surprising in the environment of this invention.
The advantageous use of recycle in a chlorofluorination reaction is disclosed in U.S.P. 3,442,962. The environmen~ of the present invention is significantly different from that of U.S.P. 3,442,962, however, in that the invention environment contains a significant amount of oxygen and water which is a by-product of the Deacon reaction. Such an oxidative and hydrolytic environment would be expected to be more conducive to promoting decomposition of the starting materials herein. Surprisingly, under the conditions described herein, the loss of aliphatic ether starting materials, and chlorinated aliphatic ethers to combustion and hydrolysis is very minor.
Any combination of the above-described means of temperature control may be employed.
The process of the invention is carried out by passing the gaseous reactants through a bed of the supported catalyst material in finely divided or granular solid form. The catalyst ;~
bed may be operated as a fixed bed, that is to say by keeping the gas velocity low enough that the bed of solid catalyst particles remains essentially static. The catalyst bed may also be operated as a dynamic bed. By increasing the gas velocity of the reactants some of the catalyst particles become dynamically sùspended in the reactant gas stream. The height of the catalyst bed therefore expands. Such beds are generally referred to as "dynamic beds". As is known in the art, if the gas velocity is increased still further, all the catalyst bed particles become suspended and ultimately the bed may assume a highly turbulent condition known and referred to as a fluidized bed.
Exact conditions required to establish a fluidized bed condition depend on the particle size of the catalyst components, the gas ;~ - -78~Si5 velocity, the density of the particles and other factors. A
discussion of such factors as are necessary for establishing and maintaining a ~luidized bed may be found in Wilhelm Kawak Chemical ~ngineering Progress, ~ol. 44, Page 201 (1948).
Preferably the process of the invention is carried out in a continuous manner using a reactor comprising a plurality of vertical tubes which are charged with the supported catalytic material in finely divided or granular ~orm. Preferably the catalyst is maintained in a fluidized state. The aliphatic ether starting material, the oxygen-containing gas, the chlorinating agent and hydrogen fluoride are metered into the ~`
bottom of the reactor tubes through the calibrated flowmeters.
Prior to entry into the bottom of the reactor tubes the reactants are preheated to approximately the reaction temper-ature desired. Separate feed lines should be used for materials which would otherwise prematurely react before passage to the reactor tubes. For example, ethyl ether and chlorine will react thermally if present in the same heated lines, as will HF
and CC14. Accordingly, these materials should be fed through sep-arate lines. In accordance with the description herein, optional additional feed streams may be fed into the bottom of the reactor, ~ `
such as a halogenated aliphatic ether recycle stream, and an inert diluent stream. Liquid reactants may be metered from calibrated reservoirs through pumps.
At the inlets to the fixed catalyst bed, relatively short hot zones will develop. These zones are generally ; 50-100C. higher in temperature than the reactor temperatures.
Such temperature gradients are tolerable however. If excessive temperatures are generated in the hot zones, undesirable combustion and carbonization reactions could result. In such an event, the temperatures of such hot zones should be controlled by employing any of the methods discussed herein for exotherm control.
" ~137~8~S
Pressures, temperatures, contact times and flow rates of reactants are regulated to produce the desired product composition with optimum yields and ukilizations of reactants in accordance with the discussion herein. Reaction products are continuously removed from the top of the reactor tubes.
Recovery and purification of the desired products, by-products and unreacted reactants, may be accomplished by conventional means such as distillation. For example, catalyst particles carried over in the exiting product gases may be separated by cyclones for return to the reactor. The product gases may then be cooled and partially condensed. Condensed aqueous HCl and HF are phase-separated from condensed organics, and may be recycled to the reactor after partial or complete dehydration. Condensed organics may be revaporized for further purification, or treated as a liquid phase. Organic vapors are neutralized by contacting with dilute caustic in a scrubber.
The organic vapors may then be dried by contacting with con-centrated sulfuric acid. The dried neutralized organic vapors are then compressed and fed to a distillation unit (still) to separate low boiling components, such as CO2, oxygen and other trace low boilers, from higher boiling components.
A series of continuous distillations is used to separate the higher boiling materials into discrete products. The products mày be further purified, if desired, by contacting wikh molecular sieves, or may be recycled to the reactor, depending on the product distribution desired.
A variety of modifications and variations of product recovery and purification may be employed by persons skilled in the art and will depend on the nature of the feed materials and product mixes obtained. Such procedures are well within the skill of the art and do not form a part of this invention - ~ .
7~3~35S
Materials of construction for the reactor and asso-ciated equipment should be resistant to the reactants in the environment employed. In general, metals such as Inconel and Hastelloy are sufficiently resistant to corrosion in the presence of the reactants of the oxychlorofluorination process.
The corrosion rate is lower in fluidized bed operations than in fixed bed operations. For this reason alone, fluid bed operation is preferred. In both fluid bed operation and fixed bed operation liners of fused high purity alumina (99.8%) perform well in terms of exhibiting low corrosion rates, withstanding high temperature exposure and providing good heat transfer through the reactor walls. Sintered ~nconel 600 has proved of particular value as a construction material for the dis-tributor bed supports in the fluid bed reactor.
The following examples illustrate practice of the preferred embodiment of the invention which is the oxychloro-fluorination of ethyl ether, (C2H5)2O, and attempts to practice the invention described in British Patent 745,818.
The advantages of the present invention will be apparent therefrom.
In the examples, the stated reactant feed rates were measured at 25C./atmospheric pressure, temperatures refer to degrees Centigrad~, and the following terms, unless otherwise specified, have the meanings given below.
~L~7~3~355 % HF Conversion (moles) = HF consumed x lO0 H~;~
(C H5)2O in - (C2H )~O out ethyl ether (C2H5)20 Conversion (moles) = x lO0 (C2H5)2O in %C12 Conversion (mols) = Cl2 iCl-Cln out x %HCl Utili~ation* (moles) = HCl in ~ HF consumed - Cl out x lO0 HCl in ~ HF consumed *If Cl2 is in feed, then substitute Cl2 in for HCl in.
ml = Milliliters g = Grams m2/g = Square Meters/Gram cc/g = Cubic Centimeters/Gram 1/h = Liters/Hour IcD. = Internal Diameter m/h = Moles/Hour EXAMPLE l This example demonstrates a typical preparation of AlF3, the preferred carrier material:
A 834 g. sample of l/8" diameter alumina pellets (Harshaw 20 A1-1404), having a surface area of 190 m2/g and a pore volume of 0.46 cc/g, was charged to a 2" I .D. X 22" long Inconel tubular reactor to form a bed. The reactor was immersed in a fluidized sand bath the temperature of which was controlled at 550+ 5.
During the heating up period, 25 g. of water were evolved under a small nitrogen sweep of 5 l/h. A stream of HF varying between 50-57 g/h and diluted with N2 was then introduced. A "hot spot" temperature ranging from 644 to 662 immediately developed and gradually migrated from the inlet end of the bed to the outlet end. The signs of the completion of fluorination were:
(1) HF was no longer being absorbed as measured by comparing HF input against HF output and (2) the "hot spot" temperature decreased to the levèl of the sand bath temperature of 550.
. .
~R~ 22-After 20 hours the fluorination was complete but HF introduction was continued for three hours more. The AlF3 content in the resulting catalyst pellets was 90~. The catalyst had a pore volume~of .13 cc/g and a surface area of 3.4 m2/g. X-ray diffraction pattern indicated the alpha form of AlF3.
EXAMæLE 2 This example demonstrates impregnation of the AlF3 carrier material prepared according to Example 1, with the preferred Deacon catalyst, CuC12. The catalyst was promoted with KCl.
125 ml of an aqueous solution of CuC12 2H2O ~16.0 g.) and KCl (7.0 g.) were added to the AlF3 prepared according to Example 1, which was contained in a flask under vacuum. The flask contents were shaken slightly to insure a uniform coat-ing of the pellets. After drying overnight at 100 in vacuo, the AlF3 contained 2.0~ CuC12 and 1.1% KCl or, on a metal basis, 95.3~ Al, 2.9% Cu and 1.8% K.
~XAMPLE 3 This example shows a typical oxychlorofluorination procedure carried out according to the preferred eth~l ether (C2H5)2O embodiment of the invention:
A 600 g sample of the supported catalyst prepared according to Example 2 and preconditioned by heating at 450 for two hours with HF at a flow rate of 40 g/h is charged into a 1 1/2'l I.D. x 24" long Inconel pipe reactor to a depth of 14".
The reactor is immersed into a temperature controlled sand bath at 350C. With the sand bath temperature at 350, flow of (C2H5)2O, C12, HF and N2 (as a diluent) were adjusted to give the molar ratios indicated below. Ten minutes later flow of 2 is started. Total flow is adjusted so that the contact time for 450 ml of catalyst at 350C is 5 seconds.
' : . . . .. .
.. , , . . :. ~
37i~1355 Molar Ratio (C2H5)2 1.00 C12 1.25 HF 4.0 2 1.4 N2 1 0 . 0 All gas flows are measured by calibrated flowmeters. HF flow ` is measured by a differential pressure cell and the liquid flow , is measured with a calibrated pump. AFter about one hour the temperature profile of the catalyst stabilizes.
The reaction lS conducted over a 4 hour period under the above specified conditions during which time effluent samples were taken at various intervals for analysis. Analysis for the organic components is achieved by a gas chromatograph which is connected to a mass spectrograph. The acidic components, HF, HCl, C12 and CO2 are determined by passing the samples through a caustic solution and analyzing by standard methods. The i analyses show appreciable formation of CH3CHClOC2H5, CH3CHFOC2Hs and FCH2CF20CHFCH2Cl, the expected corresponding conversions for HF and Cl2 and a significant extent of the Deacon reaction. This demonstrates that an oxychlorofluorination reaction takes place.
These examples were conducted identically to Example 3 except that the catalyst compositions vary as indicated in the following Table. The same products are identified by gas chromatographic and mass spectrographic analyses. Oxychloro-fluorination proceeds in all the examples with satisfactory levels of HF, Cl2 and ethyl ether conversions and Deacon reaction.
.
1~'7~35S
TABLE I
CAT I ON CONTE;NT
OTHER OF DEACON
EXAMPLE ~ Al Cu K METALSCATALYST**
The Deacon catalyst is used in combination with a stable, inert metal salt carrier.
By "stable" is intended to mean that the carrier is _g_ :
7i3~3~;5 dimensionally and physically skable in the sense that when used in a fixed bed reactor, no more than 20% by weight of the carrier crumbles or converts to a powder from its original granular or pelleted form after 500 hours of operation, or when used in a fluidized bed reactor, the carrier does not undergo erosion or agglomeration to the extent that the particle size distribution changes sufficiently to adversely affect the operation of the fluidized bed. Acceptable particle size distributions for fluid-ized bed reactions are set by standard engineering practice well known to persons skilled in the art. It is also a characteristic of being "stable" for the purpose of this description that the carrier is substantially non-volatile and non-melting at tempera-tures up to about 550C.
By "inert" is intended to mean that which is or becomes substantially non-reactive with the organic starting materials, HF, HCl if used or prepared in situ, C12 and 2 Some minor reac-tion with the aforementioned materials can be tolerated provided that such reaction does not adversely affect the oxychlorofluori-nation reaction or the catalyst life. Alumina (A12O3) is not con-sidered to be inert within this definition because it undergoessubstantial reaction with HF under oxychlorofluorination condi-tions. An example of a permissible minor reaction is the forma-tlon of small amounts of fluorides and/or oxyfluorides which will not further react with the aforementioned materialsO The term "inert" is not intended to exclude catalytically active materials provided such materials satisfy the other requirements for being inert as described above. For example, a material satisfying the requirements for the stable, inert, metal salt carrier as defined herein, may also function as a ~luorination or Deacon catalyst, as defined herein.
. ~ .
, ~ 7!31~5~
A preferred embodiment of the stable inert metal salt carrier are those carriers which are fluorination catalysts, such as A1~3.
A variety of metal salts meet these criteria of being stable and inert including, for example, certain chlorides, fluorides, oxyhalides, or oxides and admixtures thereof of Al, Mg, Ca, sa, V, Th, Sr, Co, Ni, Cd, Pb, Cr and Fe, or combinations thereof. Illustrative suitable metal salts are AlF3, MgF2, CaF2, BaF2, V2O3, ThF4, SrF2, CoF2, NiF2, CdF2, PbO, CrF3 and Fe2O3.
The preferred anion for the metal salt carriers is fluoride. The preferred cation is aluminum and the preferred support material i5 AlF3. Depending on the results desired, choice of the stable, inert metal salt support may have a substantial influence on the particular oxychlorofluorination reaction involved. As indicated above, the support may catalyze the fluorination reaction. It may also influence the degree of Deacon reaction obtained, the degree to which the HF reactant is utilized and the loss of start-ing materials to combustion and hydrolysis.
The metal salt used as the support may be pre-pared beforehand or formed in situ during the reaction. For example, the Deacon catalyst may be impregnated on alumina (aluminum oxide). Under oxychlorofluorination conditions, particularly exposure to EIF at elevated temperatures, the sur-face of the alumina is converted to AlF3. The process aspects of this invention employing such catalysts are considered to be part of the invention herein, although this is not a preferred mode of operation. Preferably, the support throughout the oxy-chlorofluorination reaction comprises at least about 80~ by weight of the metal salt and, still preferably, at least about 90% by weight of the metal salt. German Patent No.
2,114,457 discloses a number of chlorofluorination catalysts , .
".
'' : ,: ', ' ' ~ . :
,~ , . ..
~ ~8~5i5 including CuCl2 impregnated on a support such as aluminum oxide in which the catalyst loading is between about l-10 weight percent metal based on the total weight of the catalyst salts and the support material. It is disclosed that during the chlorofluorination reaction the surface of the aluminum oxide is presumed to be converted to AlF3, however, it is not believed possible to achieve at least 80% weight pe~cent AlF3 in this manner, principally since the normal chlorofluorination reaction temperatures are not high enough for optimum con-versions of aluminum oxide to AlF3.
The preferred support material, AlF3, may be prepared by fluorinating alumina with HF at elevated tempera-tures. The alumina starting material for the supports is commercially available. Either the commercially available alpha or gamma aluminas may be employed; however, it has been founa that a superior carrier is formed by fluorination of gamma alumina. The aluminas may be readily fluorinated in their commercially available form as granules or pellets with anhydrous HF diluted with nitrogen at temperatures ranging from about 200-650C. It is preferred to conduct a sub-stantial portion of the fluorination at the upper portion of this range, preferably at about 550-650C. Most preferred, in fact, is to maintain the temperature at about 650C. for the entire fluorination. At low fluorination temperatures a mixture of alpha and gamma forms of AlF3 is obtained. At high fluorination temperatures the alpha form of AlF3 is ob-tained. It has been found that the alpha form of AlF3 is superior to the gamma form for oxychlorofluorination purposes.
The gamma form of AlF3 may also be prepared by the fluorina-tion of AlCl3 or the thermal decomposition of (NH4)3AlF6. The alpha form may also be readily prepared by reacting Al(OH~3 ,.
. ~ :, : ~ ' '' 3L~78~55 with HF.
It is essential according to the invention process that the weight percentage of cation in the Deacon catalyst during the oxychlorofluorination reaction be in the range of 0.6-20, preferably 1-16 and, still preferably, 2-8, based on the total cation content of the Deacon catalyst and the stable, inert metal salt carrier. For the purpose of deter-mining the weight percentage of cation in the Deacon catalyst, the presence of cations in any additional metal salt promoters which are not themselves Deacon catalysts, shall be ignored.
It is within the scope of this invention to charge a supported ---Deacon catalyst to the oxychlorofluorination reaction in which the cation content of the Deacon catalyst exceeds the maximum 20 weight percent level defined herein and subsequently during the course of the o~ychlorofluorination reaction to permit the Deacon catalyst cation content to fall to within the claimed limits. Use of a concentration of Deacon catalyst substantially in excess of the above-described 20 weight percent limitation on cation concentration, however, results in an unstable catalyst with low activity and which creates corrosion problems. Such catalysts cannot be fluidized if desired and cannot be reused.
For example, in the oxychlorofluorination reaction dis- -closed in ~ritish Patent 745,818, it is disclosed that 31 weight percent CuC12 be impregnated into AlF3/NaCl. On the basis of cation sontent of the Deacon catalyst based on the total cation content of the Deacon catalyst and the support, this amounts to 38.6 weight percent. Attempts to duplicate this catalyst have failed. It has been found that such 31 weight percent CuC12 loading exceeds the absorptive capacity of the carrier by more than two-fold. Only 23 weight percent CuC12 was able to be impregnated. When this 23 weight percent CuC12 was tested in an oxychlorofluorination ' . ~ , .; . ,: .:
7l~
reaction, there was considerab]e run-off of CuC12 so that only about 14 weight percent CuC12 loading was actually achieved. This run-off and the vaporization of the excess CuC12 caused severe operating problems, such as plugging and erratic performance. The excess CuC12 also created a corrosion problem with the metallic reactor walls. A low catalytic activity was also noted with this catalyst and this was attributed to be caused by the deactivation of fluorination sites on the carrier by the excess CuC12, thus decreasing HF conversions.
Any conventional technique may be employed for placing the catalyst material on the metal salt carrier. The object is to accomplish the most uniform distribution of catalytic material on the carrier as is possible. By way of illustration the catalytic material may be sprayed upon the support particles in mixing ; devices, a solution containing the catalyst may be sprayed into a fluidized bed of the carrier particles, or the carrier particles may be simply immersed in a solution containing the catalyst material followed by evaporation of the solution.
Reaction temperatures are elevated and may vary depending on the starting material chosen, the catalyst and other factors. Generally, reaction temperatures should be maintained between about 300-600C., preferably between about 350-550C. If the reaction temperature is excessive in a particular environment/ then the combustion of the aliphatic ethers or halogenated aliphatic ehters or the hydrolysis of the halo-` genated aliphatic ethers may become excessive. If the reaction temperature is unduly low, there will be a decline in the chlori-nation and fluorination reactions. The ideal reaction temperature for a particular oxychlorofluorination environment will depend on the starting materials chosen, the catalyst and other factors, as can readily be determined by those skilled in the art assisted by 8S~
the considerations discussed above.
Contact time is critical. Contrary to the disclosureof sritish Patent 745,818 which suggests a contact time of approximately 24 seconds, it is essential not to employ a contact time over about 20 seconds. If contact times substantially above 20 seconds are employed, substantial losses to combustion and to hydrolysis occur and the production capacity per unit volume of catalyst decreases. For example, with the preferred catalyst system of CuC12 on AlF3, at approximately 24 seconds contact time, production of CO2 is 4-5 -times greater than at a contact time of approximately 2-6 seconds. If the contact times are too low, satisfactory conversion rates cannot be obtained. ~ccording- ; -ly, contact times must be maintained between about .1 to 20 seconds, preferably between about 2-12 seconds. For fixed bed ;
operation, the preferred contact time is from about 1-18 seconds and, still preferably, from about 2-6 seconds. For dynamic or fluidized bed operation, the preferred contact time is between about 3-20 seconds and, still preferably, from about 6-12 seconds.
By "contact" time (C.T.) is intended to mean essentially the residence time that the feed materials contact each other in the presence of the catalyst, or, more precisely in the case of a fixed bed design (X):
C.T.X. (seconds) =
Catalyst Volume (ml) x 273 K x 3600/sec/hr x pressure (atm) 22,~00 ml x reactor temperature ( K) x moles (reactants)/hr.
In the case of a fluid bed design (L):
C.T.L. (seconds)=superficial Gas VelocitY (ft-/sec)*
Pressure is not a critical consideration as the reactions described herein may be conducted under atmospheric *Volume of gas/sec. (ft.3/sec) cross-sectional area (ft.~) of reactor ,.
pressure or superatmospheric pressures. In the preferred ; embodiment, superatmospheric pressures are employed, preferably up to about 200 p.s.i.g. and, still pre~erably, from about 20-75 p.s.i.g.
The chlorination, fluorination and Deacon reactions are highly exothermic. It is desirable to control the exothermic heat of such reaction to avoid pyrolysis, carboni-zation, combustion and other undesirable side reactions.
Mechanical cooling means may be employed to control the exotherm, such as cooling jackets, cooling spray, cooling coils or other suitable heat exchange means. Another way to control the exotherm is by diluting the catalyst with an inert, solid material such as fused alumina.
Another way to control the exotherm is by adding an inert gas to the reaction gas stream. By~"inert gas" is intended to mean an organic or inorganic gas which is inert to reaction with the organic reactants and with chlorine, oxygenj water or HC1, but not necessarily inert to reaction with hydrogen fluoride. Illustrative suitable inert inorganic gas diluents are nitrogen, hydrogen chloride, helium and argon.
Illustrative suitable inert organic gas diluents are carbon tetra-chloride, carbon tetrafluoride and hexachloroethane.
The amount of diluent to be used is that which is needed to control the reaction temperature oE the particular reaction involved. This will depend on the amount of chlorina-tion taking place and the nature of the diluent used. The preferred amount of diluent may be readily determined by those skilled in the art. Generally, the molar ratio of the diluent to the carbon containing feed materials ranges from about .5-4:1, with the preferred ratio ranging from about 1-2:1. At the end of the reaction, the diluent may either be recycled or discarded.
"` ~LC~78855 The preferred way to control the exotherm is by recycling one or more halogenated aliphatic ethers ~rom the product mixture to the reaction mixture. The recycled halogenated aliphatic ethers may be partially chlorinated reaction products, completely chlorinated reaction products, and/or under-fluorinated reaction products. The recycled halogenated aliphatic ethers may be inert to Eurther reaction or they may be subject to further reaction. If a recycle medium is employed, about 1-6:1 molar ratio of recycled halogenated aliphatic ether to aliphatic ether starting material should be employed, with a preferred molar ratio of about 2-4:1. There is nothing critical about the upper limit for the concentration of the recycled products, except from the standpoint of unit capacity and economy.
In addition to the advantage of providing control over reaction exotherm, use of a recycle affords the advantages of higher utilization of HF, attainment of higher yields of the more fluorinated products, a more efficient use of oxygen, less combustion, higher conversion of reactants and a means of control over final product distribution. A high HF utili-zation is particularly important since recovery of s~bstantial amounts of unreacted HF for recycling is expensive and adds substantially to manufacturing costs. Recycle with underfluori-nated products results in further fluorination of the under-fluorinated recycle material and thus provides control over the desired product distribution in the final product mix.
Simple experimentation with the make-up and quantity of the I recycle in a particular environment will permit ready determina-tion of optimum HF utilization conditions and optimum conditions for achieving the product distribution desired.
.
~Q78BSS
Attainment of the above-described advantageous results with a recycle was surprising in the environment of this invention.
The advantageous use of recycle in a chlorofluorination reaction is disclosed in U.S.P. 3,442,962. The environmen~ of the present invention is significantly different from that of U.S.P. 3,442,962, however, in that the invention environment contains a significant amount of oxygen and water which is a by-product of the Deacon reaction. Such an oxidative and hydrolytic environment would be expected to be more conducive to promoting decomposition of the starting materials herein. Surprisingly, under the conditions described herein, the loss of aliphatic ether starting materials, and chlorinated aliphatic ethers to combustion and hydrolysis is very minor.
Any combination of the above-described means of temperature control may be employed.
The process of the invention is carried out by passing the gaseous reactants through a bed of the supported catalyst material in finely divided or granular solid form. The catalyst ;~
bed may be operated as a fixed bed, that is to say by keeping the gas velocity low enough that the bed of solid catalyst particles remains essentially static. The catalyst bed may also be operated as a dynamic bed. By increasing the gas velocity of the reactants some of the catalyst particles become dynamically sùspended in the reactant gas stream. The height of the catalyst bed therefore expands. Such beds are generally referred to as "dynamic beds". As is known in the art, if the gas velocity is increased still further, all the catalyst bed particles become suspended and ultimately the bed may assume a highly turbulent condition known and referred to as a fluidized bed.
Exact conditions required to establish a fluidized bed condition depend on the particle size of the catalyst components, the gas ;~ - -78~Si5 velocity, the density of the particles and other factors. A
discussion of such factors as are necessary for establishing and maintaining a ~luidized bed may be found in Wilhelm Kawak Chemical ~ngineering Progress, ~ol. 44, Page 201 (1948).
Preferably the process of the invention is carried out in a continuous manner using a reactor comprising a plurality of vertical tubes which are charged with the supported catalytic material in finely divided or granular ~orm. Preferably the catalyst is maintained in a fluidized state. The aliphatic ether starting material, the oxygen-containing gas, the chlorinating agent and hydrogen fluoride are metered into the ~`
bottom of the reactor tubes through the calibrated flowmeters.
Prior to entry into the bottom of the reactor tubes the reactants are preheated to approximately the reaction temper-ature desired. Separate feed lines should be used for materials which would otherwise prematurely react before passage to the reactor tubes. For example, ethyl ether and chlorine will react thermally if present in the same heated lines, as will HF
and CC14. Accordingly, these materials should be fed through sep-arate lines. In accordance with the description herein, optional additional feed streams may be fed into the bottom of the reactor, ~ `
such as a halogenated aliphatic ether recycle stream, and an inert diluent stream. Liquid reactants may be metered from calibrated reservoirs through pumps.
At the inlets to the fixed catalyst bed, relatively short hot zones will develop. These zones are generally ; 50-100C. higher in temperature than the reactor temperatures.
Such temperature gradients are tolerable however. If excessive temperatures are generated in the hot zones, undesirable combustion and carbonization reactions could result. In such an event, the temperatures of such hot zones should be controlled by employing any of the methods discussed herein for exotherm control.
" ~137~8~S
Pressures, temperatures, contact times and flow rates of reactants are regulated to produce the desired product composition with optimum yields and ukilizations of reactants in accordance with the discussion herein. Reaction products are continuously removed from the top of the reactor tubes.
Recovery and purification of the desired products, by-products and unreacted reactants, may be accomplished by conventional means such as distillation. For example, catalyst particles carried over in the exiting product gases may be separated by cyclones for return to the reactor. The product gases may then be cooled and partially condensed. Condensed aqueous HCl and HF are phase-separated from condensed organics, and may be recycled to the reactor after partial or complete dehydration. Condensed organics may be revaporized for further purification, or treated as a liquid phase. Organic vapors are neutralized by contacting with dilute caustic in a scrubber.
The organic vapors may then be dried by contacting with con-centrated sulfuric acid. The dried neutralized organic vapors are then compressed and fed to a distillation unit (still) to separate low boiling components, such as CO2, oxygen and other trace low boilers, from higher boiling components.
A series of continuous distillations is used to separate the higher boiling materials into discrete products. The products mày be further purified, if desired, by contacting wikh molecular sieves, or may be recycled to the reactor, depending on the product distribution desired.
A variety of modifications and variations of product recovery and purification may be employed by persons skilled in the art and will depend on the nature of the feed materials and product mixes obtained. Such procedures are well within the skill of the art and do not form a part of this invention - ~ .
7~3~35S
Materials of construction for the reactor and asso-ciated equipment should be resistant to the reactants in the environment employed. In general, metals such as Inconel and Hastelloy are sufficiently resistant to corrosion in the presence of the reactants of the oxychlorofluorination process.
The corrosion rate is lower in fluidized bed operations than in fixed bed operations. For this reason alone, fluid bed operation is preferred. In both fluid bed operation and fixed bed operation liners of fused high purity alumina (99.8%) perform well in terms of exhibiting low corrosion rates, withstanding high temperature exposure and providing good heat transfer through the reactor walls. Sintered ~nconel 600 has proved of particular value as a construction material for the dis-tributor bed supports in the fluid bed reactor.
The following examples illustrate practice of the preferred embodiment of the invention which is the oxychloro-fluorination of ethyl ether, (C2H5)2O, and attempts to practice the invention described in British Patent 745,818.
The advantages of the present invention will be apparent therefrom.
In the examples, the stated reactant feed rates were measured at 25C./atmospheric pressure, temperatures refer to degrees Centigrad~, and the following terms, unless otherwise specified, have the meanings given below.
~L~7~3~355 % HF Conversion (moles) = HF consumed x lO0 H~;~
(C H5)2O in - (C2H )~O out ethyl ether (C2H5)20 Conversion (moles) = x lO0 (C2H5)2O in %C12 Conversion (mols) = Cl2 iCl-Cln out x %HCl Utili~ation* (moles) = HCl in ~ HF consumed - Cl out x lO0 HCl in ~ HF consumed *If Cl2 is in feed, then substitute Cl2 in for HCl in.
ml = Milliliters g = Grams m2/g = Square Meters/Gram cc/g = Cubic Centimeters/Gram 1/h = Liters/Hour IcD. = Internal Diameter m/h = Moles/Hour EXAMPLE l This example demonstrates a typical preparation of AlF3, the preferred carrier material:
A 834 g. sample of l/8" diameter alumina pellets (Harshaw 20 A1-1404), having a surface area of 190 m2/g and a pore volume of 0.46 cc/g, was charged to a 2" I .D. X 22" long Inconel tubular reactor to form a bed. The reactor was immersed in a fluidized sand bath the temperature of which was controlled at 550+ 5.
During the heating up period, 25 g. of water were evolved under a small nitrogen sweep of 5 l/h. A stream of HF varying between 50-57 g/h and diluted with N2 was then introduced. A "hot spot" temperature ranging from 644 to 662 immediately developed and gradually migrated from the inlet end of the bed to the outlet end. The signs of the completion of fluorination were:
(1) HF was no longer being absorbed as measured by comparing HF input against HF output and (2) the "hot spot" temperature decreased to the levèl of the sand bath temperature of 550.
. .
~R~ 22-After 20 hours the fluorination was complete but HF introduction was continued for three hours more. The AlF3 content in the resulting catalyst pellets was 90~. The catalyst had a pore volume~of .13 cc/g and a surface area of 3.4 m2/g. X-ray diffraction pattern indicated the alpha form of AlF3.
EXAMæLE 2 This example demonstrates impregnation of the AlF3 carrier material prepared according to Example 1, with the preferred Deacon catalyst, CuC12. The catalyst was promoted with KCl.
125 ml of an aqueous solution of CuC12 2H2O ~16.0 g.) and KCl (7.0 g.) were added to the AlF3 prepared according to Example 1, which was contained in a flask under vacuum. The flask contents were shaken slightly to insure a uniform coat-ing of the pellets. After drying overnight at 100 in vacuo, the AlF3 contained 2.0~ CuC12 and 1.1% KCl or, on a metal basis, 95.3~ Al, 2.9% Cu and 1.8% K.
~XAMPLE 3 This example shows a typical oxychlorofluorination procedure carried out according to the preferred eth~l ether (C2H5)2O embodiment of the invention:
A 600 g sample of the supported catalyst prepared according to Example 2 and preconditioned by heating at 450 for two hours with HF at a flow rate of 40 g/h is charged into a 1 1/2'l I.D. x 24" long Inconel pipe reactor to a depth of 14".
The reactor is immersed into a temperature controlled sand bath at 350C. With the sand bath temperature at 350, flow of (C2H5)2O, C12, HF and N2 (as a diluent) were adjusted to give the molar ratios indicated below. Ten minutes later flow of 2 is started. Total flow is adjusted so that the contact time for 450 ml of catalyst at 350C is 5 seconds.
' : . . . .. .
.. , , . . :. ~
37i~1355 Molar Ratio (C2H5)2 1.00 C12 1.25 HF 4.0 2 1.4 N2 1 0 . 0 All gas flows are measured by calibrated flowmeters. HF flow ` is measured by a differential pressure cell and the liquid flow , is measured with a calibrated pump. AFter about one hour the temperature profile of the catalyst stabilizes.
The reaction lS conducted over a 4 hour period under the above specified conditions during which time effluent samples were taken at various intervals for analysis. Analysis for the organic components is achieved by a gas chromatograph which is connected to a mass spectrograph. The acidic components, HF, HCl, C12 and CO2 are determined by passing the samples through a caustic solution and analyzing by standard methods. The i analyses show appreciable formation of CH3CHClOC2H5, CH3CHFOC2Hs and FCH2CF20CHFCH2Cl, the expected corresponding conversions for HF and Cl2 and a significant extent of the Deacon reaction. This demonstrates that an oxychlorofluorination reaction takes place.
These examples were conducted identically to Example 3 except that the catalyst compositions vary as indicated in the following Table. The same products are identified by gas chromatographic and mass spectrographic analyses. Oxychloro-fluorination proceeds in all the examples with satisfactory levels of HF, Cl2 and ethyl ether conversions and Deacon reaction.
.
1~'7~35S
TABLE I
CAT I ON CONTE;NT
OTHER OF DEACON
EXAMPLE ~ Al Cu K METALSCATALYST**
3 95.3 2.9 1.8 3.0 -
4 74.316.0 9.7 17.8 ; 5 99.1 .60 .34 .60 6 78.2 8.0 4.9 La 8.9 9.3 7 86.3 ~.8 1.7 La 9.2 3.1 ; 8 94.3 2.9 1.8 Fe* 1.0 4.0 9 85.4 2.7 1.7 Th 10.2 3.1 84.2 8.6 2.7 La 3.0 9~2 Ce 1.5 . .
11 91.3 2.8 --- Cs 5.9 3.0 12 67.5 13.3 --~ Ta 19.2 16.5 * Additional Deacon Catalyst ** Based on total cation content of the Deacon Catalyst and metal salt carrier, excluding promoters.
; This Example demonstrates an oxychlorofluorination reaction in which the chlorine is generated in situ by the reaction of HF with a chlorine-containing aliphatic ether starting material. A 620 ml ~629 g.) sample of granular , Cr2O3 was impregnated with 7.8 % CuC12/3.5 % KCl to give a catalyst having a metal composition of 90.6 % Cr, 6.3 % Cu and 3.1 ~ K (Deacon cation concentration - 6.5 %). An HF stream at the rate of 50 g/h was passed through the impregnated material for eight hours at a temperature ranging from 340 to 410 to form CrF3. On the basis of weight gain, the CrF3 content of the catalyst was about 42~.
A gaseous mixture of (C2H5)2O, (C2H4C1)2O, 2 mole ratio of 1.0/1.0/3.0/1.5 is passed through the thus prepared CrF3 catalyst at 400 and with a contact time of about 13.6 -25- ..
' - . . . .
: . ' ' ' ' ~
lC117B~355 ~ seconds. After about one hour, gas chromatographic analysis of ; the effluent shows the presence of CH3CHClOC2H5, CH3CHFOC2Hs and FCH2CF2OCHFCH2Cl. An analysis of the acidic components in the effluent shows an appreciable conversion of HF and a signifi-cant extent of the Deacon reaction. The analysis demonstrates that an oxychlorofluorination reaction takes place.
A 450 ml sample of 1/4 inch diameter BaSO4 pellets was impregnated with 6.0~ CuC12 and 1.7% KC1 to give a catalyst having a metal composition of 93.6% Ba, 4.8% Cu and 1.6% K
(Deacon cation concentration - 4.9%). ~ gaseous mix~ure of (C2H5)2O/C12/HF/O2/CC14 in the mole ratio of 4.0/1.0/2.0/1.5/2.0 is passed through a bed of the catalyst at 350. The contact time is 10.8 seconds.
Analysis of the effluent for organic and acidic com-ponents shows essentially the same results as described in Example 3.
A 616 g sample of 1/8 inch diameter MgO pellets was treated with HP at 40 g/h for eight hours and then at 50 g/h for 7 hours. A slight N2 dilution was maintained. The tempera-ture was gradually increased from 25 to 506 during the heating period. Based on the weight gain, the fluorinated MgO had a 75% MgF2 content.
A 400 ml (617.5g) sample of fluorinated MgO was impregnated with 2.0% CuC12 and 1.1% KCl to giYe a catalyst having a metal composition of 96.7% Mg, 2.1% Cu and 1.2% K
(Deacon catalyst cation concentration - 2.1%).
A gaseous mixture of (C2H5)2O/C12/HF/O2 having a molar ratio of 4.0/1.0/2.0/1.5 is passed through a bed of the catalyst at 450. The contact time is 10 seconds.
~L07~855 :.
Analysis of the effluent for organic and acidic com-ponents shows essentially the same results as described in Example 3.
Example 3 is repeated, except that a recycle consisting of an equimolar mixture of CH3CHClOC2H5 and FCH2CF2OCHFCH2Cl is employed. The amount of recycle is equal to 1.5 of recycle per mole of (C2H5)2O charged. Flow rate of the recycle is about .75 m/h. Analysis of the effluent for organic and acidic components shows essentially the same results as described in Example 3, except that a highèr yield of more highly fluorinated ' products is obtained, and better control of the reaction exotherm is obtained as well as a kigher utilization of HF.
Examples 17-18 show the comparative results of oxychlorofluorination reactions on ethyl ether with a catalyst composition attempted to be prepared according to British ` Patent 745,818 versus a typical catalyst composition according to this invention.
The parameters for the oxychlorofluorination reaction are as follows:
Charge (Vol.) of Catalyst 110 ml (10/20 mesh) Reaction Temperature 440 Contact Time (seconds) 3 Preparation of Catalyst of Britich Patent 745,818 A sample of A12(SiF6)3 was mixed with 9% NaCl and pellets of about 1/4" diameter were formed. The pellets were then heated to 950 to drive off SiF4 gas.
It was attempted to impregnate the resulting AlF3 pellets with 31% CuC12 loading as prescribed in the British patent. This corresponds to 45.7% Al, 38.6% Cu and 15.7% Na , ':
```` 1~7~ 5~
or a Deacon cation concentration of 45.8 ~. It was only possible to achieve a 23 ~ CuC12 loading corresponding to 52.2 ~ Al, 30.0 ~ Cu and 17.B ~ Na and a Deacon catalyst cation concentration of 36.4 ~.
Preparation of the Comparison Catalyst The comparison catalyst was prepared by the high temperature fluorination of a commercial alumina (~arshaw Al-0104) followed by impregnation with CuC12/KCl as described in EXAMPLE 2 herein.
The reactions with both catalysts are performed in an alumina lined one inch tubular reactor. Catalyst bed height is 14 inches. Oxychlorofluorination takes place with both catalysts. During the reaction with the British patent catalyst, there is considerable run-off of the CuC12o This decreases the CuC12 content to 14.1 % corresponding to 60.6 % Al, 18.8 % Cu and 20.6 % Na and a Deacon catalyst cation concentration of 23.6 %. The run-off of CuC12 causes considerable operating problems due to plugging, undue vaporization~ excessive corrosion and lower activity due to deactivation of the fluorination sites on the carrier. Furthermore, the British patent catalyst is not fluidizable. With the comparison catalyst according to the present invention, there is no run-off of CuC12 and accordingly no accompanying operating problems due to plugging, undue vaporization, corrosion, or low activity. Furthermore, the comparison catalyst is fluidizable.
These examples demonstrate the oxychlorofluorination of (C2H5)2O with a fluidized catalyst bed. The reactor is a ceramic lined pipe, 4 inches in diameter and 20 feet long. A sintered Inconel perforated disc at the bot~om of the reactor serves to support the fluid bed and distribute the incoming gaseous reactants.
' . : , ~ . .. :.:
8~35S
, The catalyst used in these examples is a commercial powdered AlF3 which is impregnated with CuC12/KCl to give a composition of 91.3% Al, 5.7% Cu and 3.0% K (Deacon catalyst :
cation concentration - 5.8%). A sieve analysis of the coated catalyst shows the mean particle size to be 81.8 microns.
The following Table shows the conditions used and the results obtained:
TABLE II
Example 19 20 10 Catalyst Charge (liters) 12 15 Bed Height (ft) 8 10 Temperature (C) 460 460 Pressure (psig.) 20 20 Contact Time (seconds) 8.5 10.8 Gas Velocity (ft/sec) 0.95 0.92 .
Feed (m/h) : HF 24.5 25.4 HCl 24.5 25.4 2 24.5 25.4 (C2H5)2 49.0 50.8 N2 69.7 Product Composition :
Analysis of the effluent for organic and acidic com-ponents shows essentially the same results as described in Example 3.
A 180 ml. sample (3/16" pellets) of a AlF3 catalyst which consisted of a mixture of 40 % of the alpha form and 60 %
: of the gamma form was coated with CuC12/KCl to give a metal composition which was 97.7 % Al, 1.5 % Cu and 0.8 % K (Deacon catalyst cation concentration -1.5 %). The catalyst is charged to a 1" x 20" Inconel tubular reactor and an oxy-i chlorofluorination reaction is conducted as generally des-cribed in EXAMPLE 3. A gaseous mixture of (C2H5)2O/HCl/HF/O2 having a molarratio of 2.0/1.0/1.0/1/0 is passed through a bed of the catalyst at 434. The contact time is 4.9 seconds.
,: . ,- .
~', ' ,, . ' ''' :
' Analysis of the effluent for organic and acidic components shows essentially the same results as described in Example 3.
. EXAMPLE 2 2 A 20 ml. sample (10-20 mesh size3 of alpha AlF3 was coated with CuC12/KCl to give a metal composition of 87,7 ~ Al, 7.7 % Cu and 4.6 % K (Deacon catalyst cation concentration -8.7 %). This composition is charged to a 1" x 20" tubular Inco-` nel reactor and an oxychlorofluorination reaction is per-formed as generally described in EXAMPLE 3. A gaseous mixture of (C2H5)2O/HCl/HF/O2 having a molar ratio of 2.0/1.0/1.0/1.0 i5 passed through a bed of the catalyst at 419. The contact time is 1.7 seconds. Analysis of the effluent for organic and acidic components shows essentially the same results as described in Example 3.
Oxychlorofluorination reactions are conducted as des-cribed in EXAMPLE 3, except with conditions, starting materials and catalyst compositions changed as described in the following Table:
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U~ ~D ~ . . . .
~ ~ . o ~ . ~ o~ ~ Ln,, O ~ ~ o ~ ~ ~ ~ 001` ~1 ~ d td C~
i~ I~ I~1--~ . . o o u~ o o o u~ n o o In ~~ ~ ~~ ~ ~ ~
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~ u~ o o o o o o In OIn In In Lr) O
S ~ ~o o u~ In O O ~ In1-- ~ ~1~ In E~
H ~1 H ~
O ~In In ~i r-lr-l ~ 1 ~ ~ "
O OC ) ~n ~ ~ P
~) O ~) -. .
'~ N ~t~ t~l ~) O
~4~ ~ o ¢~ oe4 ~ 1~
O ~rl ~ ~qs~ ~ ~1 ~1 u~ ~ c~ m P E~ u~ u z u ~
o ~ ~ ~ ~ ~ ~ ~ ~o ~ ~ o O ~ O~1 0 ~ --I h~1 ~ ~~I Z 5-1~I Z
~ ~ ~ o ~ m ~ m ~ ~1 o u -- m u rl ~ U O
; p o a) ~ X
h -IJ X O ~ 0 O
s~a) ~ ~I h I rl ~C ~ a) X O
~ ~ Xo a~
,5~ ; o ~o O ~ O
~ ~1 Ya) ~ Y ~ ~1 a~
1:~ Id a) ~ X ~ O X~i 1 ~1 ~ ~ ~a~ o ~ ~1 0 U
Y ~ ~ ~ O
111~ ~ ~ k I O ~~ I ~1~
',y ~d ~ ~ O ~ ~ ~o er y a~ ; o Y ~~ o Y `
P~ ~ ~ In ~ ~ 00 ~O J~ N~ ~ Lr~ ~D
X
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~ 1~'7~3~S~
The oxychlorofluorination reactions proceed in a satisfactory manner in all of Examples 23-36.
. .
-32- ~
, :'
11 91.3 2.8 --- Cs 5.9 3.0 12 67.5 13.3 --~ Ta 19.2 16.5 * Additional Deacon Catalyst ** Based on total cation content of the Deacon Catalyst and metal salt carrier, excluding promoters.
; This Example demonstrates an oxychlorofluorination reaction in which the chlorine is generated in situ by the reaction of HF with a chlorine-containing aliphatic ether starting material. A 620 ml ~629 g.) sample of granular , Cr2O3 was impregnated with 7.8 % CuC12/3.5 % KCl to give a catalyst having a metal composition of 90.6 % Cr, 6.3 % Cu and 3.1 ~ K (Deacon cation concentration - 6.5 %). An HF stream at the rate of 50 g/h was passed through the impregnated material for eight hours at a temperature ranging from 340 to 410 to form CrF3. On the basis of weight gain, the CrF3 content of the catalyst was about 42~.
A gaseous mixture of (C2H5)2O, (C2H4C1)2O, 2 mole ratio of 1.0/1.0/3.0/1.5 is passed through the thus prepared CrF3 catalyst at 400 and with a contact time of about 13.6 -25- ..
' - . . . .
: . ' ' ' ' ~
lC117B~355 ~ seconds. After about one hour, gas chromatographic analysis of ; the effluent shows the presence of CH3CHClOC2H5, CH3CHFOC2Hs and FCH2CF2OCHFCH2Cl. An analysis of the acidic components in the effluent shows an appreciable conversion of HF and a signifi-cant extent of the Deacon reaction. The analysis demonstrates that an oxychlorofluorination reaction takes place.
A 450 ml sample of 1/4 inch diameter BaSO4 pellets was impregnated with 6.0~ CuC12 and 1.7% KC1 to give a catalyst having a metal composition of 93.6% Ba, 4.8% Cu and 1.6% K
(Deacon cation concentration - 4.9%). ~ gaseous mix~ure of (C2H5)2O/C12/HF/O2/CC14 in the mole ratio of 4.0/1.0/2.0/1.5/2.0 is passed through a bed of the catalyst at 350. The contact time is 10.8 seconds.
Analysis of the effluent for organic and acidic com-ponents shows essentially the same results as described in Example 3.
A 616 g sample of 1/8 inch diameter MgO pellets was treated with HP at 40 g/h for eight hours and then at 50 g/h for 7 hours. A slight N2 dilution was maintained. The tempera-ture was gradually increased from 25 to 506 during the heating period. Based on the weight gain, the fluorinated MgO had a 75% MgF2 content.
A 400 ml (617.5g) sample of fluorinated MgO was impregnated with 2.0% CuC12 and 1.1% KCl to giYe a catalyst having a metal composition of 96.7% Mg, 2.1% Cu and 1.2% K
(Deacon catalyst cation concentration - 2.1%).
A gaseous mixture of (C2H5)2O/C12/HF/O2 having a molar ratio of 4.0/1.0/2.0/1.5 is passed through a bed of the catalyst at 450. The contact time is 10 seconds.
~L07~855 :.
Analysis of the effluent for organic and acidic com-ponents shows essentially the same results as described in Example 3.
Example 3 is repeated, except that a recycle consisting of an equimolar mixture of CH3CHClOC2H5 and FCH2CF2OCHFCH2Cl is employed. The amount of recycle is equal to 1.5 of recycle per mole of (C2H5)2O charged. Flow rate of the recycle is about .75 m/h. Analysis of the effluent for organic and acidic components shows essentially the same results as described in Example 3, except that a highèr yield of more highly fluorinated ' products is obtained, and better control of the reaction exotherm is obtained as well as a kigher utilization of HF.
Examples 17-18 show the comparative results of oxychlorofluorination reactions on ethyl ether with a catalyst composition attempted to be prepared according to British ` Patent 745,818 versus a typical catalyst composition according to this invention.
The parameters for the oxychlorofluorination reaction are as follows:
Charge (Vol.) of Catalyst 110 ml (10/20 mesh) Reaction Temperature 440 Contact Time (seconds) 3 Preparation of Catalyst of Britich Patent 745,818 A sample of A12(SiF6)3 was mixed with 9% NaCl and pellets of about 1/4" diameter were formed. The pellets were then heated to 950 to drive off SiF4 gas.
It was attempted to impregnate the resulting AlF3 pellets with 31% CuC12 loading as prescribed in the British patent. This corresponds to 45.7% Al, 38.6% Cu and 15.7% Na , ':
```` 1~7~ 5~
or a Deacon cation concentration of 45.8 ~. It was only possible to achieve a 23 ~ CuC12 loading corresponding to 52.2 ~ Al, 30.0 ~ Cu and 17.B ~ Na and a Deacon catalyst cation concentration of 36.4 ~.
Preparation of the Comparison Catalyst The comparison catalyst was prepared by the high temperature fluorination of a commercial alumina (~arshaw Al-0104) followed by impregnation with CuC12/KCl as described in EXAMPLE 2 herein.
The reactions with both catalysts are performed in an alumina lined one inch tubular reactor. Catalyst bed height is 14 inches. Oxychlorofluorination takes place with both catalysts. During the reaction with the British patent catalyst, there is considerable run-off of the CuC12o This decreases the CuC12 content to 14.1 % corresponding to 60.6 % Al, 18.8 % Cu and 20.6 % Na and a Deacon catalyst cation concentration of 23.6 %. The run-off of CuC12 causes considerable operating problems due to plugging, undue vaporization~ excessive corrosion and lower activity due to deactivation of the fluorination sites on the carrier. Furthermore, the British patent catalyst is not fluidizable. With the comparison catalyst according to the present invention, there is no run-off of CuC12 and accordingly no accompanying operating problems due to plugging, undue vaporization, corrosion, or low activity. Furthermore, the comparison catalyst is fluidizable.
These examples demonstrate the oxychlorofluorination of (C2H5)2O with a fluidized catalyst bed. The reactor is a ceramic lined pipe, 4 inches in diameter and 20 feet long. A sintered Inconel perforated disc at the bot~om of the reactor serves to support the fluid bed and distribute the incoming gaseous reactants.
' . : , ~ . .. :.:
8~35S
, The catalyst used in these examples is a commercial powdered AlF3 which is impregnated with CuC12/KCl to give a composition of 91.3% Al, 5.7% Cu and 3.0% K (Deacon catalyst :
cation concentration - 5.8%). A sieve analysis of the coated catalyst shows the mean particle size to be 81.8 microns.
The following Table shows the conditions used and the results obtained:
TABLE II
Example 19 20 10 Catalyst Charge (liters) 12 15 Bed Height (ft) 8 10 Temperature (C) 460 460 Pressure (psig.) 20 20 Contact Time (seconds) 8.5 10.8 Gas Velocity (ft/sec) 0.95 0.92 .
Feed (m/h) : HF 24.5 25.4 HCl 24.5 25.4 2 24.5 25.4 (C2H5)2 49.0 50.8 N2 69.7 Product Composition :
Analysis of the effluent for organic and acidic com-ponents shows essentially the same results as described in Example 3.
A 180 ml. sample (3/16" pellets) of a AlF3 catalyst which consisted of a mixture of 40 % of the alpha form and 60 %
: of the gamma form was coated with CuC12/KCl to give a metal composition which was 97.7 % Al, 1.5 % Cu and 0.8 % K (Deacon catalyst cation concentration -1.5 %). The catalyst is charged to a 1" x 20" Inconel tubular reactor and an oxy-i chlorofluorination reaction is conducted as generally des-cribed in EXAMPLE 3. A gaseous mixture of (C2H5)2O/HCl/HF/O2 having a molarratio of 2.0/1.0/1.0/1/0 is passed through a bed of the catalyst at 434. The contact time is 4.9 seconds.
,: . ,- .
~', ' ,, . ' ''' :
' Analysis of the effluent for organic and acidic components shows essentially the same results as described in Example 3.
. EXAMPLE 2 2 A 20 ml. sample (10-20 mesh size3 of alpha AlF3 was coated with CuC12/KCl to give a metal composition of 87,7 ~ Al, 7.7 % Cu and 4.6 % K (Deacon catalyst cation concentration -8.7 %). This composition is charged to a 1" x 20" tubular Inco-` nel reactor and an oxychlorofluorination reaction is per-formed as generally described in EXAMPLE 3. A gaseous mixture of (C2H5)2O/HCl/HF/O2 having a molar ratio of 2.0/1.0/1.0/1.0 i5 passed through a bed of the catalyst at 419. The contact time is 1.7 seconds. Analysis of the effluent for organic and acidic components shows essentially the same results as described in Example 3.
Oxychlorofluorination reactions are conducted as des-cribed in EXAMPLE 3, except with conditions, starting materials and catalyst compositions changed as described in the following Table:
~', ' ;
, .
..
', . ' ' ' ` , ~
.. , , ,, ... ,, , .. ~ , , '7~3~355 E~--` o ~ oo ~co Lt~ o o ~, o U~
C)--.
U~
U~ ~D ~ . . . .
~ ~ . o ~ . ~ o~ ~ Ln,, O ~ ~ o ~ ~ ~ ~ 001` ~1 ~ d td C~
i~ I~ I~1--~ . . o o u~ o o o u~ n o o In ~~ ~ ~~ ~ ~ ~
~ . .
,~ :
~ u~ o o o o o o In OIn In In Lr) O
S ~ ~o o u~ In O O ~ In1-- ~ ~1~ In E~
H ~1 H ~
O ~In In ~i r-lr-l ~ 1 ~ ~ "
O OC ) ~n ~ ~ P
~) O ~) -. .
'~ N ~t~ t~l ~) O
~4~ ~ o ¢~ oe4 ~ 1~
O ~rl ~ ~qs~ ~ ~1 ~1 u~ ~ c~ m P E~ u~ u z u ~
o ~ ~ ~ ~ ~ ~ ~ ~o ~ ~ o O ~ O~1 0 ~ --I h~1 ~ ~~I Z 5-1~I Z
~ ~ ~ o ~ m ~ m ~ ~1 o u -- m u rl ~ U O
; p o a) ~ X
h -IJ X O ~ 0 O
s~a) ~ ~I h I rl ~C ~ a) X O
~ ~ Xo a~
,5~ ; o ~o O ~ O
~ ~1 Ya) ~ Y ~ ~1 a~
1:~ Id a) ~ X ~ O X~i 1 ~1 ~ ~ ~a~ o ~ ~1 0 U
Y ~ ~ ~ O
111~ ~ ~ k I O ~~ I ~1~
',y ~d ~ ~ O ~ ~ ~o er y a~ ; o Y ~~ o Y `
P~ ~ ~ In ~ ~ 00 ~O J~ N~ ~ Lr~ ~D
X
.. , . . . , . ` . . .- :
~ 1~'7~3~S~
The oxychlorofluorination reactions proceed in a satisfactory manner in all of Examples 23-36.
. .
-32- ~
, :'
Claims (49)
1. The process for the production of chlorofluorinated aliphatic ethers which comprises reacting a gaseous mixture of a starting material selected from an aliphatic ether and a halo-genated aliphatic ether in which the halogen atoms are selected from chlorine and fluorine, or mixtures thereof, at least .10 mole oxygen in an oxygen-containing gas for each C-H bond in the starting material, at least about 1 mole HC1 or equivalent amount of C12 for each C-H bond present in the starting material, and HF, in the presence of a Deacon catalyst supported by a stable, inert metal salt carrier, with the weight percentage of cation in the Deacon catalyst ranging from about 0.6-20 based on the total cation content of the Deacon catalyst and metal salt carrier, at elevated temperatures and with a contact time of from about .1-20 seconds.
2. The process according to claim l in which the start-ing material is an aliphatic ether.
3. The process according to claim 1 in which the catalyst bed is maintained as a fixed bed and in which the con-tact time is from about .1-18 seconds.
4. The process according to claim 3 in which the con-tact time is from about 2-5 seconds.
5. The process according to claim 1 in which the catalyst bed is maintained as a dynamic bed.
6. The process according to claim 5 in which the catalyst bed is maintained as a fluidized bed and in which the contact time is from about 3-20 seconds.
7. The process according to claim 6 in which the contact time is from about 6-12 seconds.
8. The process according to claim 1 in which at least 0.25 mole oxygen in an oxygen-containing gas is employed.
9. The process according to claim 1 in which at least 0.50 mole oxygen is an oxygen-containing gas is employed.
10, The process according to claim 1 in which the Dea-con catalyst is a metal halide.
11. The process according to claim 10 in which the Dea-con catalyst is promoted with a metal salt in which the metal is selected from the group consisting of Li, Na, K, Rb, La and Cs.
12. The process according to claim 1 in which the Dea-con catalyst is a copper halide.
13. The process according to claim 1 in which the Dea-con catalyst is CuC12.
14. The process according to claim 1 in which the carrier is a metal salt in which the metal is selected from the group consisting of Al, Mg, Ca, Ba, V, Th, Sr, Co, Ni, Cd, Pb, Cr and Fe, or combinations thereof.
15. The process according to claim 14 in which the anion of the salt is a fluoride.
16. The process according to claim 15 in which the metal salt is A1F3.
17. The process according to claim 16 in which the A1F3 is substantially in alpha form.
18. The process according to claim 2 in which at least .75 mole oxygen in an oxygen-containing gas per C-H bond in the starting material is employed.
19. The process according to claim 2 in which the aliphatic ether is acyclic, saturated, contains only C, H and O
atoms and from 2-10 carbon atoms.
atoms and from 2-10 carbon atoms.
20. The process according to claim 2 in which the ali-phatic ether is cyclic, saturated, contains only C, H and O atoms and from 2-10 carbon atoms.
21. The process according to claim 19 in which the start-ing material is a halogenated aliphatic ether.
22. The process according to claim 19 in which the ali-phatic ether is ethyl ether.
23. The process according to claim 20 in which the ali-phatic ether is tetrahydrofuran.
24. The process according to claim 19 in which the con-tact time is from about 2-12 seconds.
25. The process according to claim 19 in which the start-ing material containing a gaseous mixture is diluted with an inert gas.
26. The process according to claim 19 in which one or more halogenated aliphatic ethers from the product mixture are recycled to the reaction mixture.
27. The process according to claim 19 in which the weight percentage of cation in the Deacon catalyst ranges from about 1-16 based on the total cation content of the Deacon catalyst and metal salt carrier.
28. The process according to claim 19 in which the catalyst bed is maintained as a dynamic bed.
29. The process according to claim 27 in which the catalyst bed is maintained as a fluidized bed.
30. The process according to claim 27 in which the elevated temperatures range from about 300-500°C.
31. The process according to claim 27 in which the Dea-con catalyst is a metal halide.
32. The process according to claim 31 in which the Dea-con catalyst is promoted with a metal salt in which the metal is selected from the group consisting of Li, Na, K, Rb, La and Cs.
33. The process according to claim 27 in which the Dea-con catalyst is a copper halide.
34. The process according to claim 27 in which the Dea-con catalyst is CuC12.
35. The process according to claim 27 in which the carrier is a metal salt in which the metal is selected from the group consisting of Al, Mg, Ca, Ba, V, Th, Sr, Co, Ni, Cd, Pb, Cr and Fe.
36. The process according to claim 35 in which the anion of the salt is a fluoride.
37. The process according to claim 36 in which the metal salt is A1F3.
38. The process according to claim 27 in which the aliphatic ether is ethyl ether.
39. The process according to claim 27 in which the aliphatic ether is tetrahydrofuran.
40. The process according to claim 27 in which one or more halogenated aliphatic ethers from the product mixture are recycled to the reaction mixture.
41. The process according to claim 27 in which the reac-tion gas mixture is diluted with an inert gas.
42. The process according to claim 27 in which the weight percent of cation in the Deacon catalyst ranges from about 2-8 based on the total cation content of the Deacon catalyst and metal salt.
43. The process according to claim 27 in which the Dea-con catalyst is a metal halide and in which the carrier is a metal salt in which the metal is selected from the group consist-ing of Al Mg, Ca, Ba, Th, Sr, Co, Ni, Cd, Pb, Cr and Fe.
44. The process according to claim 43 in which the Dea-con catalyst is CuC12.
45. The process according to claim 43 in which the anion of the metal salt carrier is a fluoride.
46. The proces according to claim 45 in which the metal salt carrier is A1F3.
47. The process according to claim 44 in which the metal salt carrier is A1F3.
48, The process according to claim 46 in which the A1F3 is substantially in the alpha form.
49. The process according to claim 43 in which one or more halogenated aliphatic ethers from the product mixture are recycled to the reaction mixture.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US64283175A | 1975-12-22 | 1975-12-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1078855A true CA1078855A (en) | 1980-06-03 |
Family
ID=24578206
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA267,965A Expired CA1078855A (en) | 1975-12-22 | 1976-12-15 | Process for the production of chlorofluorinated aliphatic ethers |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1078855A (en) |
-
1976
- 1976-12-15 CA CA267,965A patent/CA1078855A/en not_active Expired
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