Glymes as benign co-solvents for CaO-catalyzed transesterification of soybean oil to biodiesel.

Highlights: [•] Glymes were found to reduce the saponification reaction during biodiesel preparation. [•] Glymes are benign solvents with low toxicity and volatility. [•] Glymes are miscible with triglycerides including soybean oil. [•] SEM suggests a dissolution–agglomeration process of CaO surface in glyme. [•] A 99% stoichiometric conversion of soybean oil was achieved in glymes in 4h. [ABSTRACT FROM AUTHOR]