Technological Evaluation of the Implementation of Advanced Process Control at the RFCC Unit of PT Kilang Pertamina Internasional

Abstract

The RFCC (Resid Fluid Catalytic Cracking) unit at PT Kilang Pertamina Internasional RU IV Cilacap has a design capacity of 62 MBSD, using Low Sulphur Wax Residue (LSWR) from CDU II and Vacuum Gas Oil from HVU I/II as feedstock. In this unit, heavy hydrocarbon feed is cracked using a fluidized catalyst to produce lighter and higher-value products. The main RFCC products include propylene, RFCC naphtha, LPG, Light Cycle Oil (LCO), Decant Oil (DCO), and Heavy Cycle Oil (HCO). Propylene is produced in Unit 104, Propylene Recovery, as the overhead product of the C3 Splitter after further treatment through the propylene drier and propylene treater. RFCC naphtha from Units 101/102 is treated in Unit 105 Gasoline Hydrotreating (Prime-G) to remove sulphur contaminants and produce desulphurized RFCC gasoline as a high-octane blending component. LPG is produced through gas concentration, LPG Merox treatment, and separation in Unit 104. Meanwhile, LCO and DCO may be sent to product tanks or used as refinery fuel oil blending components, while HCO can be recycled to the reactor as heat carrier or feed under certain operating conditions. Current RFCC operation still faces several challenges, including reactor outlet temperature fluctuations affecting conversion stability, main column temperature profile fluctuations influencing valuable product yield, and prolonged operating-condition tuning in Unit 104 to maintain high-purity propane while keeping propylene on specification. Therefore, the implementation of Advanced Process Control (APC) is considered a strategic optimization approach to improve operating stability, maximize valuable product recovery, increase efficiency, and support energy savings in the RFCC unit.