A gas stream containing at least one fluorine compound selected from the group
consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and
fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine
and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst
comprising at least one of alumina, titania, zirconia and silica, preferably a
catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania
in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively
low temperature, e.g. 200-800 C., to convert the fluorine of the fluorine
compound to hydrogen fluoride.