This invention provides a fluidized catalytic cracking apparatus and process for converting a hydrocarbon feedstock containing higher concentrations of Conradson Carbon Residue (CCR), metal impurities, etc into lighter products by employing two riser reactors in which the feed impurities are removed using an adsorbent in a first riser reactor and cracking a portion of first riser reactor liquid product in a second riser reactor to lighter products using the active catalyst thus eliminating the catalyst deactivation due to metal, impurities and FCC catalyst activity dilution effect to achieve a better conversion and higher catalyst longevity.