110th Anniversary: Transesterification of Corn Oil to Biodiesel by Ion Exchange Resins with Macroporous Structure

This study investigated the transesterification of corn oil into fatty acid methyl esters (FAME) and free fatty acid (FFA) conversion using macroporous strong acid cationic (Purolite CT175 in H+ and Na+ forms) and strong base anionic (Purolite A500TLPIus in OH- form) resins. Taguchi experimental design was used for the optimization of molar ratio of methanol to oil (6:1, 12:1, and 18:1 mol/mol), reaction time (24, 36, 48 h), reaction temperature (63, 65, 67 degrees C), and resin loading (12, 16, 20 wt %). For both ionic forms of Purolite CT175, resin loading of 12 wt %, reaction temperature of 65 degrees C, methanol to oil (MeOH:Oil) mol ratio of 18:1, and reaction time of 24 h were found as optimum conditions. On the other hand, 12 wt % of resin loading, 65 degrees C of reaction temperature, 6:1 of methanol to oil molar ratio, and 24 h of reaction time were obtained as optimum conditions for Purolite A500TLPlus resin in OH- form. The maximal FFA conversions of approximately 80%, 81%, and 76% were achieved at optimum conditions for H- and Na+ forms of Purolite CT175 resin and OH- form of Purolite A500TLPlus resin, respectively.