Application of Fine Porous Ultrafiltration Pan Membranes for Used Engine Oil Treatment

The application of polyacrylonitrile (PAN) ultrafiltration membranes to the treatment of used engine oil (UEO) was investigated. A two-stage purification scheme was developed, comprising filtration through PAN membranes with pore sizes of 23 nm (M-20) and 4.9 nm (M-5). The results demonstrated that the M-5 membrane exhibits high permeability, 2.0 ± 0.4 L/(m2 h bar), and strong fouling resistance, with toluene washing restoring up to 93% of its initial permeability. Physicochemical and elemental analyses confirmed a reduction in oxygen, sulfur, metals, and high-molecular-weight compounds. Spectroscopic studies (FTIR and NMR) revealed efficient removal of polycyclic aromatic hydrocarbons and oxidation products. The two-stage filtration system employing PAN membranes provides efficient treatment of UEO, making the proposed method promising for further industrial application.