Purification of Biodiesel via Nanofluid using Liquid-Liquid Extraction in a Membrane Contactor

Recently, attention has been paid to nanofluids due to their contribution to enhancing heat and mass transfer in different industrial applications. Consequently, a nanofluid composed of SiO2 nanoparticles (NPs) and distilled water as base fluid was adopted as a solvent to promote the removal of impurities, methanol, and glycerol, from crude biodiesel using liquid-liquid extraction in the membrane contactor. The presence of NPs significantly enhanced the methanol and glycerol removal efficiency. The optimum concentration of NPs in nanofluid was 0.01 wt%. It was found that adding 0.01 wt% of NPs to the distilled water increased the methanol removal efficiency from 76.4% to 93.1% upon using crude biodiesel with methanol and glycerol content of 2000 ppm and 1 wt%, respectively, at a constant flow rate of solvent and biodiesel of 200 mL min⎼1. Meanwhile, the glycerol removal efficiency increased from 76.2% to 94.5%. The results revealed that the solvent flow rate was the controlling mass transfer step.