Biodiesel from Rice Bran Oil: Transesterification by Tin Compounds

The transesterification of rice bran oil with methanol has been studied in the presence of sulfuric acid (H 2 SO 4 ), tin chloride dihydrate (SnCl 2 ·2H 2 O), tin 2-ethylhexanoate (Sn(C 8 H 15 O 2 ) 2 ), dibutyl tin oxide ((C 4 H 9 ) 2 SnO), and dibutyl tin dilaurate ((C 4 H 9 ) 2 Sn(C 12 H 23 O 2 ) 2 ), known commercially as DBTDL. Through the comparative analysis among the catalysts, we observed that the complex DBTDL presented the best performance, with a yield of 68.9% in 4 h using molar ratio 400:100:1 (methanol:oil:catalyst). These results evidenced the viability of the use of metallic compounds as catalysts in the obtainment of biodiesel, an interesting alternative to basic and acid catalysis.