Patent ID: 6352676
Filing Date: 2002-03-05
Classification: B01D

Abstract:
A process of destroying a fluorine specie selected from the group consisting of fluorine, chlorine trifluoride and mixtures thereof in a gas containing said fluorine specie and one or more gas components selected from the group consisting of N2, O2, Ar, He, SiF4, NF3, CF4, C2F6, CHF3, SF6 and mixtures thereof by contacting said gas at a temperature in the range of 150 to 500Â° C. with at least one fluidized bed of metal particles, selected from the group consisting if iron, nickel, copper, calcium, magnesium, manganese, cobalt, tin and mixtures thereof, capable of reacting with said fluorine specie, said particles consisting essentially of particles having a particle size no greater than 300 microns, but wherein up to 10 wt. % of said bed of metal particles are large particles having a particle size sufficiently larger than 300 microns to assist in mixing of said bed of metal particles, said contacting selected from the group consisting of (a) alternately contacting said gas with one of a plurality of switching parallel connected fluidized beds of metal particles and switching beds when the height of the bed being contacted with said gas increases to a bed height corresponding to substantially stoichiometric reaction of said fluorine specie with said metal particles, and (b) continuously contacting said gas with a single fluidized bed where fresh metal particles are added to an inlet near a base of said fluidized bed and metal particles that have been reacted with said fluorine specie are removed above said inlet and below a freeboard of said fluidized bed.