A nano-sized solid acid synthesized from rice hull ash for biodiesel production

Abstract

A nano-sized solid acid was synthesized from rice hull ash by acid activation. The solid acid was characterized by XRD, FT-IR, TEM and solid-state NMR spectroscopy. The characterization results show that the solid acid is amorphous silica with –OH and –SO₃H functional acid groups. The TEM images show that the particle size range of the solid acid catalyst is 50–100 nm. In addition, the catalytic results indicate that the solid acid exhibits excellent activity and recyclability for the transesterification reaction of soybean oil with methanol, suggesting promising industrial applications in biodiesel production.