TRANSESTERIFICATION OF PALM OIL AT NEAR-CRITICAL CONDITIONS USING SULFONATED CARBON-BASED ACID CATALYST

Abstract

This study aims to investigate the production of biodiesel by transesterification of purified palm oil (PPO) at near-critical conditions using a carbon-based catalyst, synthesized by incomplete carbonization of naphthalene in sulfuric acid. The catalyst shows good activity for the reaction; with the most suitable condition found to be at a methanol-to-PPO molar ratio of 12:1, a carbon-based catalyst-to-PPO mass ratio of 0.5 wt.%, a reaction time of 30 min, and a reaction temperature of 270°C. This resulted in a FAME yield of about 95%. However, FAME yields were found to decrease after each reaction cycle from around 95% in the first to 61% in the second cycle, and to only 45% in the third cycle, as a result of catalyst deactivation due to acid leaching.

Keywords:

• Carbon-based catalyst
• FAMEs
• Purified palm oil
• Sulfonation
• Supercritical
• Transesterification

Acknowledgments

The authors gratefully acknowledge the Thailand Research Fund (TRF) and the Office of Higher Education Commission (CHE) and Higher Education Promotion and National Research University Development (AM1088A) for the financial support.