Molar ratio Biodiesel 10 Esters 7 Biodiesel production 6 Transesterification 6 Catalyst activity 5 Catalysts 5 Fatty acids 5 Oils and fats 4 Palm oil 4 Transesterifications 4 Waste cooking oil 4 Esterification 3 Fatty acid methyl ester 3 Heterogeneous catalyst 3 Nanocatalysts 3 Palm fatty acid distillate 3 Physicochemical properties 3 Reaction temperature 3 Reusability 3 Acetone 2 Batch reactors 2 Biomass 2 Carbon dioxide 2 Catalysis 2 Catalyst loadings 2 Catalytic esterification 2 Catalytic performance 2 Chromium compounds 2 Combustion 2