The present invention relates to a process for producing butadiene from ethanol, in two reaction steps, comprising a step a) of converting ethanol into acetaldehyde and a step b) of conversion into butadiene, said step b) simultaneously implementing a reaction step and a regeneration step in (n+n/2) fixed-bed reactors, n being equal to 4 or a multiple thereof, comprising a catalyst, said regeneration step comprising four successive regeneration phases, said step b) also implementing three regeneration loops.

The presently disclosed subject matter relates to methods and systems for alkane dehydrogenation. In a particular non-limiting embodiment, the presently disclosed subject matter provides a system for the dehydrogenation of alkanes that includes two or more reactors configured to perform a dehydrogenation reaction of an alkane in the presence of a catalyst to produce an olefin and a catalyst regenerator, coupled to each of the two or more reactors through at least one transfer line to a regenerator, for the regeneration of spent catalyst.

The disclosure provides an improved endothermic hydrocarbon conversion process that comprises reacting a hydrocarbon with a multi-component catalyst bed, and regenerating the catalyst bed with air, where the air used in regeneration step and hydrocarbon are at low air to hydrocarbon ratios and optionally at near-atmospheric pressures.

The disclosure provides an improved endothermic hydrocarbon conversion process that comprises reacting a hydrocarbon with a multi-component catalyst bed, and regenerating the catalyst bed with air, where the air used in regeneration step and hydrocarbon are at low air to hydrocarbon ratios and optionally at near-atmospheric pressures.

There is provided a method for producing an optionally substituted olefin, comprising the steps of: dehydrogenating an optionally substituted alcohol in a first reaction zone comprising a first catalyst supported on a porous silica-based particle to form an optionally substituted carbonyl at a first set of reaction conditions; converting the optionally substituted alcohol and the optionally substituted carbonyl from the first reaction zone in a second reaction zone at a second set of reaction conditions that is different to the first set of reaction conditions and is selected to form the optionally substituted olefin, wherein the second reaction zone comprises a second catalyst supported on a porous silica-based particle. There is also provided a system for producing the optionally substituted olefin.

A method is provided comprising exposing a supported heterogeneous metathesis catalyst to an olefin compound for an activation time at an activation temperature; exposing the activated supported heterogeneous metathesis catalyst to a reactant capable of undergoing a metathesis reaction for a reaction time at a reaction temperature to produce metathesis products; and exposing the deactivated supported heterogeneous metathesis catalyst to a regenerating compound for a regeneration time at a regeneration temperature. The activity of the regenerated supported heterogeneous metathesis catalyst may be substantially the same or greater than the activity of the activated supported heterogeneous metathesis catalyst prior to deactivation. The activation temperature may be greater than the reaction temperature. The regenerating compound may be a second olefin compound or an inert gas.

A method is provided comprising exposing a supported heterogeneous metathesis catalyst to an olefin compound for an activation time at an activation temperature; exposing the activated supported heterogeneous metathesis catalyst to a reactant capable of undergoing a metathesis reaction for a reaction time at a reaction temperature to produce metathesis products; and exposing the deactivated supported heterogeneous metathesis catalyst to a regenerating compound for a regeneration time at a regeneration temperature. The activity of the regenerated supported heterogeneous metathesis catalyst may be substantially the same or greater than the activity of the activated supported heterogeneous metathesis catalyst prior to deactivation. The activation temperature may be greater than the reaction temperature. The regenerating compound may be a second olefin compound or an inert gas.

A process of catalytically dehydrogenating an alkane to an alkene, using Cr.sub.2O.sub.3 as a catalyst, where the catalyst is reduced concurrently with the dehydrogenation by using CO as a reducing gas. In reducing the catalyst with CO, CO.sub.2 is produced, which may be reacted with H.sub.2 produced by the dehydrogenation, to form CO and H.sub.2O by the reverse water-gas shift reaction. A Cu O heat-releasing material may be included with the catalyst in the reactor. The CO reducing gas reduces CuO to form Cu and CO.sub.2, releasing heat. The CO.sub.2 produced by reducing the Cu O may also be reacted with H.sub.2 produced by the dehydrogenation, to form CO and H.sub.2O by the reverse water-gas shift reaction.

The invention relates to a fluorination process, alternately comprising reaction stages and regeneration stages, wherein the reaction stages comprise reacting a chlorinated compound with hydrogen fluoride in gas phase in the presence of a fluorination catalyst to produce a fluorinated compound, and the regeneration stages comprise contacting the fluorination catalyst with an oxidizing agent-containing gas flow.

The invention relates to a fluorination process, alternately comprising reaction stages and regeneration stages, wherein the reaction stages comprise reacting a chlorinated compound with hydrogen fluoride in gas phase in the presence of a fluorination catalyst to produce a fluorinated compound, and the regeneration stages comprise contacting the fluorination catalyst with an oxidizing agent-containing gas flow.