BiodieselEsterificationTransesterificationBifunctional solid acidbase catalystsLow-cost oil feedstocksWASTE COOKING OILMETAL-ORGANIC FRAMEWORKSACIDIC IONIC LIQUIDJATROPHA-CURCAS OILONE-STEP PRODUCTIONSULFATED TIN OXIDEHETEROGENEOUS CATALYSTSOYBEAN OILVEGETABLE-OILSSIMULTANEOUS TRANSESTERIFICATION