Process Simulation of a 5,000 to 30,000 bbl/Day Modular Hydroskimming Refinery for Selected Nigerian Crude Oils Using Aspen HYSYS

Process simulation, design evaluation, and techno-economic analysis of a modular hydroskimming refinery with a processing capacity of 5,000–30,000 bbl/day for selected Nigerian crude oils (Yoho, Bonga, and Qua Iboe) using Aspen HYSYS was considered in this research. Crude oil assays were characterized into pseudo-components using the Peng–Robinson equation of state to accurately represent thermodynamic behaviour. The refinery configuration comprised a Crude Distillation Unit (CDU), naphtha stabilization and splitting units, a naphtha hydrotreating reactor, and a catalytic reforming unit. Simulation results demonstrated a linear increase in product yields with increasing throughput, confirming steady-state operability and scalability across the evaluated capacity range. Product distribution analysis revealed that Bonga crude (API 27.7°) yielded higher heavy fuel oil fractions exceeding 30–35 wt%, while Qua Iboe crude (API 37.3°) produced higher yields of light and middle distillates, with naphtha and kerosene fractions reaching approximately 25–35 wt%. Yoho crude (API 41°) exhibited intermediate behaviour, with balanced distribution across product streams. The CDU operated effectively within a temperature range of 104–644°F and pressure range of 20–49 psig, ensuring efficient fractionation. The hydrotreating unit achieved optimal performance at 340°C and 25 bar, while the catalytic reformer operating at 500°C and 15 bar produced high-octane reformate with stable hydrogen recycle. Economic analysis indicated that capital cost increased from approximately $26 million at 5,000 bbl/day to $78 million at 30,000 bbl/day, while the unit capital cost decreased from about $5,200/bbl/day to $2,600/bbl/day, demonstrating significant economies of scale. This research confirms that modular hydroskimming refineries are technically viable, operationally stable, and economically scalable for processing diverse Nigerian crude oils, providing a strategic solution for decentralized refining and energy security enhancement.