Heterogeneous Acid-Catalyzed Biodiesel Production from Crude Tall Oil: A Low-Grade and Less Expensive Feedstock

Abstract

The present study indicates that solid acid catalysis of crude tall oil (CTO) over a WO₃/ZrO₂ catalyst is effective in converting the CTO fatty acids components into biodiesel in high yield. Preparation of the catalyst by an impregnation method was selected and WO₃ activity was best at a loading mass fraction of 5% to ZrO₂ support and activation at 500°C for five hours under air at atmospheric pressure. Optimal reaction conditions were reaction temperature at 250°C; methanol to CTO molar ratio at 10; reaction time four hours, catalyst mass fraction of 3%; and stirring intensity at 625 rpm. The conversion at optimal reaction conditions was 70%. The catalyst was highly active at temperatures higher than 200°C. The biodiesel produced met some, but not all, the diesel quality parameters stipulated by standard specifications such as ASTM D6751 and EN14214.

KEYWORDS:

• Biodiesel
• catalyst
• crude tall oil
• heterogeneous