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 2 or a multiple thereof, comprising a catalyst, said regeneration step comprising four successive regeneration phases, said step b) also implementing a regeneration loop for the inert gas and at least one regeneration loop for the gas streams comprising oxygen.

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 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 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 2 or a multiple thereof, comprising a catalyst, said regeneration step comprising four successive regeneration phases, said step b) also implementing a regeneration loop for the inert gas and at least one regeneration loop for the gas streams comprising oxygen.

An industrial furnace and a method for roasting or regenerating spent petroleum catalysts. The furnace particularly includes a device to set the catalysts in motion along the bottom of the furnace to cause the catalysts to circulate from the inlet towards the outlet of the furnace; a first zone decarbonizing the spent catalysts to obtain decarbonized catalysts, followed by: a second zone including a plurality of oxygen feed devices distributed along the length of the second zone and placing the decarbonized catalysts in contact with the oxygen feed, the second zone desulfurizing the decarbonized catalysts to obtain roasted or regenerated catalysts.

An industrial furnace and a method for roasting or regenerating spent petroleum catalysts. The furnace particularly includes a device to set the catalysts in motion along the bottom of the furnace to cause the catalysts to circulate from the inlet towards the outlet of the furnace; a first zone decarbonizing the spent catalysts to obtain decarbonized catalysts, followed by: a second zone including a plurality of oxygen feed devices distributed along the length of the second zone and placing the decarbonized catalysts in contact with the oxygen feed, the second zone desulfurizing the decarbonized catalysts to obtain roasted or regenerated catalysts.