This invention relates to a method for preparing 1,2-difluoroethylene and/or 1,1,2-trifluoroethane, comprising a step of performing at least one fluorination reaction by bringing at least one halide selected from the group consisting of haloethanes represented by general formula (1) CHX.sup.1X.sup.2CH.sub.2X.sup.3 (wherein X.sup.1, X.sup.2, and X.sup.3 are the same or different, and represent Cl, Br, or F) and haloethylenes represented by general formula (2) CHX.sup.4═CHX.sup.5 (wherein X.sup.4 and X.sup.5 are the same or different, and represent Cl, Br or F, with the proviso that the case in which X.sup.4 and X.sup.5 are both F is excluded).

This invention relates to a method for preparing 1,2-difluoroethylene and/or 1,1,2-trifluoroethane, comprising a step of performing at least one fluorination reaction by bringing at least one halide selected from the group consisting of haloethanes represented by general formula (1) CHX.sup.1X.sup.2CH.sub.2X.sup.3 (wherein X.sup.1, X.sup.2, and X.sup.3 are the same or different, and represent Cl, Br, or F) and haloethylenes represented by general formula (2) CHX.sup.4═CHX.sup.5 (wherein X.sup.4 and X.sup.5 are the same or different, and represent Cl, Br or F, with the proviso that the case in which X.sup.4 and X.sup.5 are both F is excluded).

A new chromium-containing fluorination catalyst is described. The catalyst comprises an amount of zinc that promotes activity. The zinc is contained in aggregates which have a size across their largest dimension of up to 1 micron. The aggregates are distributed throughout at least the surface region of the catalyst and greater than 40 weight % of the aggregates contain a concentration of zinc that is within ±1 weight % of the modal concentration of zinc in those aggregates.

A new chromium-containing fluorination catalyst is described. The catalyst comprises an amount of zinc that promotes activity. The zinc is contained in aggregates which have a size across their largest dimension of up to 1 micron. The aggregates are distributed throughout at least the surface region of the catalyst and greater than 40 weight % of the aggregates contain a concentration of zinc that is within ±1 weight % of the modal concentration of zinc in those aggregates.

A new chromium-containing fluorination catalyst is described. The catalyst comprises an amount of zinc that promotes activity. The zinc is contained in aggregates which have a size across their largest dimension of up to 1 micron. The aggregates are distributed throughout at least the surface region of the catalyst and greater than 40 weight % of the aggregates contain a concentration of zinc that is within ±1 weight % of the modal concentration of zinc in those aggregates.

The present invention relates to a process for modifying the fluorine distribution in a hydrocarbon compound, comprising a step of making contact between said hydrocarbon compound and a catalytic composition comprising a chromium-based catalyst, said process being performed in a reactor made of a material comprising a base layer made of a material M1 and an inner layer made of a material M2, said base layer and said inner layer being laid against each other by bonding.

A process for the fluorination of a chlorinated C3 alkane or alkene compound having at least one chlorine atom into a fluorinated C3 alkane or alkene compound having at least one fluorine atom includes the following steps: a) contacting, in a reactor, the chlorinated compound with hydrogen fluoride in gas phase in the presence of a fluorination catalyst to produce a fluorinated compound, and b) regenerating the fluorination catalyst used in step a). The step (b) of regenerating the fluorination catalyst comprises (c) the treatment of said fluorination catalyst with an oxidizing agent-containing gas flow to form an oxidized fluorination catalyst, and (d) the treatment of the oxidized fluorination catalyst obtained in step (c) with a gaseous mixture comprising a reducing agent and an inert gas. The catalyst regenerated in step b) is reused in step a) and the reducing agent is selected from C.sub.1-C.sub.10 hydrohalocarbons.

A process for the fluorination of a chlorinated C3 alkane or alkene compound having at least one chlorine atom into a fluorinated C3 alkane or alkene compound having at least one fluorine atom includes the following steps: a) contacting, in a reactor, the chlorinated compound with hydrogen fluoride in gas phase in the presence of a fluorination catalyst to produce a fluorinated compound, and b) regenerating the fluorination catalyst used in step a). The step (b) of regenerating the fluorination catalyst comprises (c) the treatment of said fluorination catalyst with an oxidizing agent-containing gas flow to form an oxidized fluorination catalyst, and (d) the treatment of the oxidized fluorination catalyst obtained in step (c) with a gaseous mixture comprising a reducing agent and an inert gas. The catalyst regenerated in step b) is reused in step a) and the reducing agent is selected from C.sub.1-C.sub.10 hydrohalocarbons.

A process for the fluorination of a chlorinated C3 alkane or alkene compound having at least one chlorine atom into a fluorinated C3 alkane or alkene compound having at least one fluorine atom includes the following steps: a) contacting, in a reactor, the chlorinated compound with hydrogen fluoride in gas phase in the presence of a fluorination catalyst to produce a fluorinated compound, and b) regenerating the fluorination catalyst used in step a). The step (b) of regenerating the fluorination catalyst comprises (c) the treatment of said fluorination catalyst with an oxidizing agent-containing gas flow to form an oxidized fluorination catalyst, and (d) the treatment of the oxidized fluorination catalyst obtained in step (c) with a gaseous mixture comprising a reducing agent and an inert gas. The catalyst regenerated in step b) is reused in step a) and the reducing agent is selected from C.sub.1-C.sub.10 hydrohalocarbons.

Disclosed is a process for the synthesis of fluorinated olefins, and in particularly preferred embodiments tetrafluorinated olefins having F on an unsaturated, non-terminal carbon, such as 2,3,3,3-tetrafluoropropene. The preferred processes of the present invention in accordance with one embodiment generally comprise: (a) reacting a compound of formula (I)

X.sup.1X.sup.2(I)

with a compound of formula (II)

CX.sup.1X.sup.2X.sup.3CX.sup.1CX.sup.1X.sup.2(II)

to produce a reaction product comprising a compound of formula (III)

CF.sub.3CHX.sup.1CH.sub.2X.sup.2(III), and (b) exposing said compound of formula (III) to reaction conditions effective to convert said compound of formula (III) to a compound of formula (IV)

CF.sub.3CZCH.sub.2(IV)

wherein X.sup.1, X.sup.2, and X.sup.3 are each independently selected from the group consisting of hydrogen, chlorine, bromine, fluorine and iodine, provided that X.sup.1 and X.sup.2 in formula (I) are not both hydrogen and Z is Cl, I, Br, or F.