Acid and Base Catalysed Transesterification of Used Vegetable (Gutter) and Non-Edible Oils to Fatty Acid Methyl Esters

Transesterification of oils to their corresponding fatty acids methyl esters (FAME) has recently been recognised as an easy and cost effective technology for biodiesel production, mainly on account of the desirable physiochemical properties of the biodiesel produced. In this study, Jatropha (Jatropha curcas), Karanja (Pongania pinnata), Linseed (Linum usitatissimum) and used vegetable oils (Gutter oil) biodiesel production was optimised. Two-stage catalytic process (acid esterification and base transesterification) were used and the effects of factors like catalyst concentration (% w/w) from 0.6% to 1.1%, molar ratio (6:1 to 12:1), temperature (60–70°C) and time (1–6h) were investigated. The optimal yields for Linseed oil, Jatropha, Karanja and Gutter oils were 88.7%, 96%, 92.41% and 96.10%, respectively. The physical properties were then determined and compared with ASTM standards. It was concluded that catalytic transesterification of all oils studied here were economically viable and could be commercialised.