Compositions of chromium oxyfluoride or fluoride catalysts, their preparation and their use in gas-phase processes
The present invention relates to a process for modifying the fluorine distribution in a hydrocarbon compound in the presence of a catalyst, characterized by the use, as catalyst, of a solid composition comprising at least one component containing chromium oxyfluoride or fluoride of empirical formula Cr x M (1-x) O r F s , where 2r+s is greater than or equal to 2.9 and less than 6, M is a metal chosen from columns 2 to 12 of the Periodic Table of the Elements, x has a value from 0.9 to 1, s is greater than 0 and less than or equal to 6 and r is greater than or equal to 0 and less than 3, the said solid composition having a crystallinity of less than 20% by weight. The present invention also relates to the solid composition per se.
1. A process for modifying the fluorine distribution in a hydrocarbon compound in the presence of a catalyst, the catalyst being a solid composition containing at least one component containing chromium oxyfluoride or fluoride of empirical formula Cr x M (1-x) O r F s ,
wherein
2r+s is greater than or equal to 2.9 and less than 6,
M is a metal chosen from the group consisting of Zn, Mg, Co, Mn and Ni,
x has a value from 0.9 to 0.999,
s is greater than 0 and less than or equal to 6,
and r is greater than or equal to 0 and less than 3,
wherein the solid composition has a crystallinity of less than 20% by weight; and
wherein the fluorine content of the hydrocarbon compound is increased by reacting the hydrocarbon compound with hydrogen fluoride in the gas phase in the presence of the solid composition, the hydrocarbon compound being a saturated halogenated hydrocarbon or an unsaturated halogenated hydrocarbon or an unsaturated hydrocarbon.
2. The process according to claim 1 , wherein the solid composition has a crystallinity of less than 15%.
3. The process according to claim 1 , wherein M is Zn.
4. The process according to claim 1 , wherein the hydrocarbon compound is chosen from the group consisting of tetrachloropropene, chlorotrifluoropropene, pentachloropropane, dichlorotrifluoropropane, trichlorodifluoropropane, tetrafluorochloropropane, tetrachlorofluoropropane, dichlorodifluoropropene, trichlorofluoropropene, pentafluoropropane and their mixtures.
5. The process according to claim 4 , wherein the hydrocarbon compound is chosen from the group consisting of 2 chloro-3,3,3-trifluoro-1-propene (HFCO-1233xf), 2,3-dichloro-1,1,1-trifluoropropane (HCFC-243db), 1,1,1,2,3-pentachloropropane (HCC-240db), 1,1,2,2,3-pentachloropropane (HCC-240aa), 1,1,1,3,3-pentachloropropane (HCC-240fa), 1,1,2,3-tetrachloro-1-propene (HCO-1230xa), 2,3,3,3-tetrachloro-1-propene (HCO-1230xf), 1,1,3,3-tetrachloro-1-propene (HCO-1230za), 1,3,3,3-tetrachloro-1-propene (HCO-1230zd), 1,1,1,2,2-pentafluoropropane (HFC-245cb) and 1-chloro-3,3,3-trifluoro-1-propene (HCFO-1233zd), and their mixtures.
6. The process according to claim 1 , wherein the component containing chromium oxyfluoride or fluoride is of empirical formula Cr x M (1-x) O r F s , where r is greater than or equal to 0 and less than 2.62, s is greater than or equal to [((0.16 r)+0.52)]/0.92, on condition that s is greater than or equal to 0.76 and less than 6.
7. A process for modifying the fluorine distribution in a hydrocarbon compound in the presence of a catalyst, the catalyst being a solid composition containing at least one component containing chromium oxyfluoride or fluoride of empirical formula Cr x M (1-x) O r F s ,
Wherein
2r+s is greater than or equal to 2.9 and less than 6,
M is a metal from columns 2 to 12 of the Periodic Table of the Elements,
x has a value from 0.9 to 0.999,0078840-000366,
s is greater than 0 and less than or equal to 6, and
r is greater than or equal to 0 and less than 3,
wherein the solid composition has a crystallinity of less than 20% by weight and contains a support chosen from the group consisting of activated carbon, alumina, magnesium fluoride and aluminium fluoride; and
wherein the fluorine content of the hydrocarbon compound is increased by reacting the hydrocarbon compound with hydrogen fluoride in the gas phase in the presence of the solid composition, the hydrocarbon compound being a saturated halogenated hydrocarbon or an unsaturated halogenated hydrocarbon or an unsaturated hydrocarbon.
8. The process according to claim 7 , wherein the solid composition has a specific surface between 1 and 100 m 2 /g.
9. The process according to claim 1 , wherein the component containing chromium oxyfluoride or fluoride is of empirical formula Cr x M (1-x) O r F s , where r is greater than or equal to 0 and less than 2.05, s is greater than or equal to [((0.4 r)+1.3)]/0.8, on condition that s is greater than or equal to 1.90 and less than 6.