A process for regenerating a catalyst containing ruthenium or ruthenium compounds, which includes, optionally at elevated temperature, subjecting the catalyst to a hydrogen halide treatment, particularly a gas stream comprising hydrogen chloride, under non-oxidative conditions and, optionally at reduced temperature, to at least a two-stage oxidative post-treatment. The catalyst may have been poisoned by sulfur compounds. After the removal of sulfur, the catalyst is subjected to an oxidative post-treatment.

A process is described for regenerating a catalyst comprising ruthenium or ruthenium compounds, which has been poisoned by sulfur compounds, in which the catalyst, optionally at elevated temperature, is subjected to treatment with a hydrogen halide, particularly a gas stream comprising hydrogen chloride, under non-oxidative conditions and additionally, optionally at reduced temperature, to an at least two-stage oxidative post-treatment.

A process is described for regenerating a catalyst comprising ruthenium or ruthenium compounds, which has been poisoned by sulfur compounds, in which the catalyst, optionally at elevated temperature, is subjected to treatment with a hydrogen halide, particularly a gas stream comprising hydrogen chloride, under non-oxidative conditions and additionally, optionally at reduced temperature, to an at least two-stage oxidative post-treatment.

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.

Multi-reactor systems with aromatization reactor vessels containing a catalyst with low surface area and pore volume, followed in series by aromatization reactor vessels containing a catalyst with high surface area and pore volume, are disclosed. Related reforming methods using the different aromatization catalysts also are described.

Multi-reactor systems with aromatization reactor vessels containing a catalyst with low surface area and pore volume, followed in series by aromatization reactor vessels containing a catalyst with high surface area and pore volume, are disclosed. Related reforming methods using the different aromatization catalysts also are described.

Multi-reactor systems with aromatization reactor vessels containing a catalyst with low surface area and pore volume, followed in series by aromatization reactor vessels containing a catalyst with high surface area and pore volume, are disclosed. Related reforming methods using the different aromatization catalysts also are described.

Multi-reactor systems with aromatization reactor vessels containing a catalyst with low surface area and pore volume, followed in series by aromatization reactor vessels containing a catalyst with high surface area and pore volume, are disclosed. Related reforming methods using the different aromatization catalysts also are described.

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.