Acid Treatment of a Clay-type Nanocatalyst and Its Effect on Esterification Reaction for Biofuel Production

In this research, a novel clay-type nanocatalyst (kaolin) was treated with hydrochloric acid and used in biofuel production as the catalyst of the esterification process. The properties of the synthesized nanocatalysts were characterized by XRD and FESEM analyses. Moreover, it showed that acid treatment of kaolin could be useful in the esterification process and increase biofuel conversion. In this regard, experimental results showed that biodiesel conversion of raw kaolin and kaolin treated by ۰.۱, ۰.۵, and ۱ M of HCl was ۶۸.۵, ۶۹.۸, ۸۴.۱, and ۵۶.۴, respectively. Increasing acid concentration up to ۰.۵ M increased biodiesel production, and higher concentration decreased biodiesel production. This was because of the being destructed after being treated with highly concentrated acid. The catalytic performance of the nanocatalysts was evaluated at ۱۱۰°C, methanol/oil molar ratio of ۲۰ with ۱۰ wt% of catalyst loading and ۳ hours of reaction duration.