A comparative study of KOH/Al2O3 and KOH/NaY catalysts for biodiesel production via transesterification from palm oil

The transesterification of palm oil to methyl esters (biodiesel) was studied using KOH loaded on Al2O3 and NaY zeolite supports as heterogeneous catalysts. Reaction parameters such as reaction time, wt% KOH loading, molar ratio of oil to methanol, and amount of catalyst were optimized for the production of biodiesel. The 25wt% KOH/Al2O3 and 10wt% KOH/NaY catalysts are suggested here to be the best formula due to their biodiesel yield of 91.07% at temperatures below 70°C within 2–3h at a 1:15 molar ratio of palm oil to methanol and a catalyst amount of 3–6wt%. The leaching of potassium species in both spent catalysts was observed. The amount of leached potassium species of the KOH/Al2O3 was somewhat higher compared to that of the KOH/NaY catalyst. The prepared catalysts were characterized by using several techniques such as XRD, BET, TPD, and XRF.