The Middle Distillates and Lower Olefins Selective process (Milos), a new process started by Shell Global Solutions introduces an additional riser to the Fluid Catalytic Cracker (FCC) column to maximise the yield of the diesel and propylene fractions. Given the option to add to new or existing facilities of FCC columns, Milos can be operated in different modes according to the fraction the refinery operators want to augment. Milos doubles the propylene yield from the FCC compared with standard operation when applied to PP production. Feedstocks including FCC naphtha, coker naphtha, Visbreaker naphtha, vegetable oil, paraffinic vacuum gas oil and others can be handed by Shell's Milos. When FCC naphtha is cracked using Milos riser in FCC, 15.5%wt propylene, 7.5%wt gas and 5% iso-butane is obtained.