Abstract: Compared with vacuum residue, FCC slurry is low in viscosity, conradson carbon residue, hydrogen and resin content but high in aromatic content and gravity. The influence of blending FCC slurry on delayed coking was analyzed and the design optimization was proposed. The commercial results in a new 1.2 Mt/a delayed coking unit indicate that processing the feed blending with 25% FCC slurry, the coke and gas oil yield increase 2.7% and 2%, respectively， while the light oil (petrol + diesel) and total liquid yield reduce 5% and 3%, respectively. The residue carbon and aromatic content of LCGO, and the coke ash and volatile matter of coke are all increased. The remarkable wears of the heat exchangers, the fractionator, furnace, pumps and pipes and other equipments are observed, which impact the long-term operation. The optimization of the heat exchanger baffles, furnace type, furnace tube thickness, coke cleaning methods and fractionator process can reduce the catalyst deposition on the equipments and retard the coking on the surface of furnace tubes, thus extend the operation life time.

Key words: delayed coking, FCC slurry, heat exchanger, furnace, fractionator