PROCESS FOR REACTOR PASSIVATION

摘要

Disclosed is a process for passivating a surface of a dehydrochlorination reactor comprising: stopping a flow of hydrochlorofluoropropane to a reactor, passing a gas mixture comprising hydrogen gas through the reactor at a temperature of at least 25° C. for a period of time sufficient to restore the selectivity of a dehydrochlorination reaction, stopping the flow of the hydrogen gas mixture, and resuming the flow of hydrochlorofluoropropane to the dehydrochlorination reaction. Also disclosed is a process for producing a fluoropropene of formula CF3CX═CX2, wherein each X is F or H, at least one X is H and at least one X is F, comprising pyrolyzing a hydrochlorofluoropropane of formula CF3CXYCX2Y, wherein each X is F or H, at least one X is H, and at least one X is F and one Y is Cl and the other Y is H, in the gas-phase in the absence of a catalyst in a reaction vessel, maintained at a temperature high enough to effect the pyrolysis of said hydrochlorofluoropropane to said fluoropropene, and wherein said reaction vessel is periodically subjected to a passivation step to passivate the inner surface of said reaction vessel. Also disclosed is a process for producing a fluoropropene of formula CF3CX═CX2, wherein each X is F or H, at least one X is H and at least one X is F, comprising pyrolyzing a hydrochlorofluoropropane of formula CF3CXYCX2Y, wherein each X is F or H, at least one X is H, and at least one X is F and one Y is Cl and the other Y is H, in the gas-phase in the absence of a catalyst in a reaction vessel, maintained at a temperature high enough to effect the pyrolysis of said hydrochlorofluoropropane to said fluoropropene, and wherein said hydrochlorofiuoropropane comprises less than 300 ppm of hydrogen fluoride.