Abstract: In a selective hydrogenation process wherein at least two catalyst beds in series are utilized, the temperature of the feed stream to the first catalyst bed and the temperature of the feed stream from the first catalyst bed to the second catalyst bed is controlled so as to maintain a desired reaction temperature in both catalyst beds and to maintain a desired relationship between the amount of the impurity selectively hydrogenated in the first catalyst bed and the amount of the impurity selectively hydrogenated in the second catalyst bed.

Abstract: Apparatus for regenerating at elevated temperature a fluidized mass of particles, e.g., a catalyst used in treatment of hydrocarbons, e.g., fluidized catalysts cracking of oil, is disclosed.Several operations can be effected in the apparatus, each of them alone or in various combinations.An operation basic to the overall operation, always effected by the apparatus, is the continuous circulation of dense phase particles undergoing regeneration from a dense phase or fluidized regeneration vessel to a hot surge vessel and from the latter back into the dense phase bed in the regeneration vessel.Used catalyst can be in part passed to the hot surge vessel whenever it is tending to cause undue temperature rise in the regeneration vessel.Fresh or unused catalyst can be fed to the regeneration vessel continuously or intermittently responsive to sensed temperature change in said vessel and/or to said hot surge vessel.

Abstract: Method and apparatus for regenerating at elevated temperature at fluidized mass of particles, e.g., a catalyst used in treatment of hydrocarbons, e.g., fluidized catalysts cracking of oil, are disclosed.Several operations can be effected, each of them alone or in various combinations.An operation basic to the overall operation, always effected, is the continuous circulation of dense phase particles undergoing regeneration from a dense phase or fluidized regeneration zone or vessel to a hot surge zone or vessel and from the latter back into the dense phase bed in the regeneration zone.Used catalyst can be in part passed to hot surge zone whenever it is tending to cause undue temperature rise in the regeneration zone.Fresh or unused catalyst can be fed to the regeneration zone continuously or intermittently responsive to sensed temperature change in said zone and/or to said hot surge zone.