In this work, various solid acid catalysts were prepared and
their reaction behavior was studied in biodiesel production from
high acid value oil. The prepared catalysts showed good activities
but it was found that the supported HPW catalysts suffered from
leaching. Cs2.5H0.5PW12O40 (CsHPW) exhibited the highest
activity and stability as compared to other supported HPW
catalysts. The reaction parameters such as temperature, catalyst
loading, and reaction time remarkably affected the reaction rate
for biodiesel production from high acid value oils and the reaction
temperature had the most significant influence on FAME
conversion among all reaction variables studied. A maximum
conversion of 90.4% was achieved at methanol to oil mixture
molar ratio 20, reaction time 10 h, reaction temperature 200 8C,
and 3% (w/w) catalyst loading in biodiesel production from 10%
oleic acid soybean oil over CsHPW. Results showed that the Csdoped
heteropoly tungstate catalysts are stable and reusable for
the production of biodiesel from low quality oils containing high
free fatty acids. Although, heterogeneous acid catalysts are not as
much active as base catalysts, process simplification and
environmental benefits encourage the use of these catalysts for
biodiesel production.