Pressure-drop reduction by oil-infused spacers

Abstract

This study explores oil-infused polydimethylsiloxane (iPDMS) feed spacers designed to reduce pressure drop in spiral-wound membrane (SWM) modules. While crucial for structural support and fouling mitigation, conventional feed spacers increase pressure drop, leading to higher energy demands. By infusing PDMS spacers with silicone oils of varying viscosities (10, 20, and 100 cSt), we achieved significant reductions in pressure drop—up to 46% compared to non-infused spacers. Lower-viscosity oils demonstrated the most pronounced improvements. Numerical simulations corroborate the experimental data, showing that the slippery surface of the oil-infused spacers minimizes flow resistance and reduces energy dissipation. These findings suggest that incorporating oil-infused spacers can enhance SWM module efficiency, offering a promising approach to lowering operational energy costs in membrane-based water treatment systems.