Synthesis of FAME from the methanolysis of palm fatty acid distillate using highly active solid oxide acid catalyst

• Active tripartite acid oxide catalyst was synthesized and employed in esterification.
• The catalyst shows good activity towards high FFA PFAD feedstock in one stage.
• Characterization revealed crystalline phases of component metals enhanced stability.
• The reusable catalyst yielded over 96.54% FAME content at suitable conditions.
• The catalyst is easy to separate from product with high recoverability.

The esterification of non-edible, low cost palm fatty acid distillate (PFAD) with methanol has been studied in heterogeneous process using ZrFeTiO, ZrFeO, and FeTiO catalysts at temperature range of 110–200 °C. The catalysts prepared by sol–gel synthesis procedure were characterized by N2 adsorption, FTIR, X-ray diffraction, and SEM/EDX. All catalysts exhibited high catalytic activity in PFAD esterification with methanol. The highest conversion to methyl esters, 96.54%, was achieved using ZrFeTiO catalyst calcined at 600 °C for 4 h after 5 h of reaction at 170 °C, 3 wt.% of catalyst loading, and methanol to oil ratio of 3:1. The catalysts were separated easily from reaction mixture and minimal leaching of active species to the reaction medium is found. It can be used in four successive reactions with stable conversions. Regeneration and reuse are feasible and easy to perform.