| (57) A process wherein lower boiling products (H) are obtained from a hydrocarbon feed
(J and/or HH) by contacting the feed with fluidized solid contact material at elevated
temperature in a riser (K), spent contact material is separated and stripped of volatile
hydrocarbons in a stripping zone (D), stripped contact material is regenerated with
oxygen-containing gas (A) in a regeneration zone (B), and hot freshly regenerated
fluidized solid contact material is returned to the riser (K), the process further
including two or more of the following:
(i) suspending hot regenerated contact material in a carbonizable lift gas at the
lower portion of the riser and injecting hydrocarbon feed higher in the riser;
(ii) charging hydrocarbon feed into the base of the riser, steam cooling a portion
of the hot freshly regenerated contact material, and contacting the hydrocarbon feed
with hot regenerated contact material upstream of where said hydrocarbon feed is contacted
with the steam cooled contact material;
(iii) cooling a portion of hot freshly regenerated contact material before returning
it to the riser; and
(iv) adding a portion of freshly heated regenerated contact material to said stripping
zone.
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