Air-sintered silicon (Si)-bonded silicon carbide (SiC) hollow fiber membranes for oil/water separation

In this work we evaluated the effect of adding Si as sintering additive into SiC for producing air-sintered hollow fiber membranes. According to crystallographic analyses, SiC and Si were converted to SiO2 after sintering at 1350 °C. The addition of 30 wt% of Si into SiC ceramic material promoted the binding of SiC particles and improved the membrane mechanical resistance to 42.25 ± 3.39 MPa after air sintering at 1350 °C. The produced asymmetric ceramic membrane presented a packed pore-network and micro-voids with pore sizes of 1.73 and 5.29 μm, respectively. The filtration of an oil/water emulsion enabled oil retention 98.75 ± 0.95 %. Cake formation was the main fouling occurrence and membrane regeneration with equivalent oil retention and similar steady sate flux was achieved after water cleaning under ultrasound irradiation. Thus, the use of Si as air-sintering aid was favorable for producing Si-bonded SiC hollow fiber membranes with suitable application for oil/water separation.