(292a) Membranes for Separation of Complex Refinery Streams

Large-scale hydrocarbon separation technologies are largely thermally driven phase-change based processes and account for roughly 45% of production energy in downstream petrochemical and manufacturing processes. Pressure-driven membranes based separation systems offer an energy-efficient, non-phase change based alternative strategy. Chemically, thermally and mechanically robust membranes can potentially lay the foundation for a “membrane revolution” in the area of hydrocarbon purification similar to the revolution that occurred in water desalination with traditional reverse osmosis membranes.

We discuss class and boiling point separation of complex liquid hydrocarbon streams using commercial ceramic membranes currently in use for water treatment applications. We have evaluated whole crudes ranging from light (Arabian Light) to heavy (Maya), studying the impact of membrane pore size, operating temperature and pressure. The membrane performance was found to be stable in batch and long-term crossflow testing under harsh chemical, thermal (up to 200°C) and mechanical (~600 psi) conditions. Fluxes were comparable to ultrafiltration (~10 GFD) with molecular weight based rejection of multi-ring aromatics, >90% rejection of microcarbon residue (MCR) and metals. To better understand the composition of permeate and retentate streams; simulated distillation (SIMDIST), elemental, MCR and total acid number (TAN) analyses were conducted.

Next, we describe the development of a separations model for the transport of thousands of molecular species in the whole crude by combining fundamental transport equations with a compositional platform. Finally, we discuss a case study from the refining and petrochemicals space providing a perspective on the potential application of these membranes.