Robust Superwetting Sintered Glass Filters for High-Pressure Separation of Emulsions with Enhanced Flux and High-Viscosity-Oil Tolerance

Abstract

High-pressure emulsion separation is vital for crude oil treatment and engine fuel dehydration, yet is hindered by materials with poor pressure resistance and difficulty in handling highly viscous oils. Herein, via simple and efficient surface modification, we fabricate two physicochemically robust sintered glass filters with superhydrophilic and superoleophilic surfaces, respectively. Under 3 bar pressure, the superhydrophilic filter rapidly separates various oil-in-water emulsions, achieving 99.4% efficiency and a flux of 21,139 L m -2 h -1 for crude emulsion. Meanwhile, tackling the more challenging waterin-oil emulsions, the superoleophilic filter not only enables ultra-fast separation from low-viscosity oil (e.g., a flux up to 50,798 L m⁻² h⁻¹ and 99.8% efficiency for n-hexane emulsion), but also excels with highly viscous oils, maintaining > 99.3% efficiency for refrigerator and dimethylsilicone oils, as well as demonstrates a 97.7% dehydration rate for ultra-high viscosity crude oil (11,557 mPa s). Crucially, we propose a paradigm shift in the separation mechanism: actively utilizing high pressure to drive separation, rather than merely tolerating it. This work provides a new strategy and valuable guidance for the treatment of viscous oil and advanced filtration.