To untangle this problem, two-stage (acid and alkali catalyzed) method was used for biodiesel synthesis. More than 90% ester was obtained when two-stage
method was used compared to ∼50% ester in single stage alkaline catalyst. In the case of mixed alcohol, a relatively smaller amount of ethyl esters
was formed along with methyl esters. Acid value, viscosity, and cetane number of all the esters prepared from WFG were within the range of the
ASTM standard. Esters obtained from WFG showed good performance as a lubricity additive.
Published by Elsevier B.V.