Processing of High-Metal Heavy Residues in Resid Fluid Catalytic Cracking: Industrial Experience and Optimization Approaches

The article addresses the challenges associated with processing heavy petroleum feedstock with high metal content in the Resid Fluid Catalytic Cracking (RFCC) unit of the Atyrau Oil Refinery. Elevated concentrations of iron, nickel, and vanadium were shown to cause rapid catalyst deactivation, deterioration of fluidization properties, and instability of the reactor–regenerator system. Analysis of industrial data revealed that the iron content in the feed significantly exceeded the design value, reaching 150 mg/kg, which resulted in increased catalyst consumption and reduced process efficiency. The industrial application of metal-passivating chemical reagents reduced the iron content by 48–62%, thereby improving catalyst performance and increasing the yield of target products. However, the use of these reagents is associated with high operating costs. Therefore, additional demetallization methods were investigated, particularly solvent deasphalting. Experimental studies on a pilot unit demonstrated that deasphalting reduced the concentrations of Fe, Ni, and V by 7–9 times and produced a deasphalted oil yield of 81.1 wt.%. The obtained product exhibited low Conradson carbon residue and improved quality, making it suitable as a feed component for catalytic cracking. An integrated approach combining chemical treatment and solvent deasphalting is proposed to improve refining efficiency and catalyst stability.