A sequential
processing for heavy
petroleum residues is disclosed which uses a separate mixture of catalyst and adsorbent. The
solid adsorbent and FCC (fluids catalytic
cracking) catalyst particles differ significant at least on particle size or density or both. The adsorbent preferably consist of calcined
coke or
metal oxides of Al, Si, or Mg having enhanced ability of selectively capture different impurities of the
residual oil. The adsorbent particles first treat the residual hydrocarbons in the riser bottom end subsequently the actual catalyst tales care of catalytic
cracking in the upper section of the riser. The spent
solid mixture is fed to the catalyst separator which uses steam at sufficiently
high velocity but at lower temperature to lift the catalyst particles out of the separator. Such a novel low temperature faster separation minimizes
Vanadium mobility and deactivation of the catalyst. A net
coke stream is withdrawn from the separator / burner especially while
processing residues above 5 wt % CCR. This allows successful
processing of even very heavy residues with CCR of 20 wt % and metals (
vanadium &
nickel) or 300 ppm, without requiring higher catalyst make up or catalyst and edsorbent cooling.