Patent FR-2922786-A1 (FR)
Title: Regenerating a catalyst for producing or reforming an aromatic hydrocarbon e.g. benzene, toluene, ortho-, meta- or paraxylene, comprises combustion of the catalyst followed by oxychlorination and calcination
Inventor: DECOODT XAVIER
IPC: B01J23/96
Filed: 2007-10-26
Abstract: Regenerating a catalyst for producing or reforming aromatic hydrocarbon, comprises (a) combustion in a combustion zone A comprising two combustion beds A1 and A2 in series; (b) oxychlorinating in an oxychlorinating zone B comprising one oxychlorinating bed, where the oxychlorinating zone B is fed by a chlorinating agent, water or water precursors and a gas comprising oxygen; and (c) calcining in a calcining zone C comprising a calcination bed. Process for regenerating a catalyst for producing or reforming aromatic hydrocarbon, comprises (a) combustion in a combustion zone A comprising two combustion beds A1 and A2 in series; (b) oxychlorinating in an oxychlorinating zone B comprising one oxychlorinating bed, where the oxychlorinating zone B is fed by a chlorinating agent, water or water precursors and a gas comprising oxygen; and (c) calcining in a calcining zone C comprising a calcinating bed, where: the zone is fed by a gas comprising at least one dry auxiliary air; the catalyst comprises a support, chlorine and at least a noble metal and serially circulating in beds A1 then A2, then in the oxychlorinating B zone then in the calcining zone C; the effluent gas from bed A1 is sent to bed A2; the gas feeding the calcining C zone circulates freely towards the oxychlorinating B zone; one auxiliary gas comprising oxygen is produced in the entrance of the calcining zone; the effluent gas from the oxychlorinating zone is partly recycled through a washing section D towards an entrance of the combustion bed A1 and A2; the effluent gas from the oxychlorinating zone is recycled passing by a blower without passing through the washing section D, at least partly towards the bed A2 and partly to the entrance of the oxychlorinating zone B; the effluent gas from the bed A2 is partly recycled through the washing section D towards the entrance of beds A1 and A2. An independent claim is included for an enclosure (2) to implement the process comprising combustion zone A comprising two combustion beds (A1) and (A2) in series, at least one oxychlorinating zone (B) comprising at least one oxychlorinating bed and one calcining zone (C) comprising a calcining bed, where: the enclosure comprises means for circulating catalyst successively through two combustion beds, the oxychlorinating and calcining zone, and a point for withdrawing gas from oxychlorinating zone, the means of withdrawing is connected to a blower; the blower is connected in downstream to a first line of recycling part of the gas towards the last combustion bed A2 and at least a second line of recycling another portion of the gas towards a point of gas introduction in the oxychlorinating zone; the point of introduction is located below the withdrawing point of the oxychlorinating zone; the second line of recycling comprises at least a point of water introduction or water precursors, at least a furnace (19) and at least a point of chlorinating agent introduction; the second line of recycling comprises a point of gas withdrawing to recirculate a portion of gas through a section D of washing in upstream of the blower, the effluent of the washing section is partly purged before circulating through a compressor; the effluent gas of the compressor is partly recycled towards the combustion beds A1 and A2; the enclosure comprises a means of withdrawing a part of the gas in a first point of the last combustion bed A2; the means of withdrawing is connected to the washing section; and the enclosure comprises a plate or other means to separate the combustion zone and oxychlorinating zone to prevent mixing of gases obtained from the combustion and the oxychlorination.