Optimization of esterification of fatty acid rubber seed oil for methyl ester synthesis in a plug flow reactor

ABSTRACT

To date, non-food vegetable oil has been considered as the primary source for biodiesel production. Rubber seed oil has high acid value (34 mgKOH/g) and can be used for biodiesel synthesis. The purpose of this study was to investigate esterification of fatty acid, which derived from rubber seed oil, in a plug flow reactor system at high temperature and low methanol consumption. Response surface methodology was applied for design experiment and optimization of esterification reaction. Temperature, methanol consumption, and sulfuric acid were chosen as variables to examine their influence in a conversion to methyl ester. At 140°C, at 5:1 methanol to fatty acid ratio (by mole), H₂SO₄ 1.5 (%v/w), and space time 20 min, the conversion to methyl ester attained 98.2%. Fourier transform infrared spectroscopy (FTIR) and gas chromatography-Mass spectrometry (GC-MS) were used for analysis and to confirm the formation of methyl ester. Methyl ester was characterized for biodiesel fuel properties in accordance to ASTM standard.

KEYWORDS:

• Biodiesel
• methyl ester
• plug flow reactor
• response surface methodology
• rubber seed oil

Funding

The financial support of VLIR-UOS project ZEN2013RIP021 (Belgium) and project 10/2012/HD-NDT (MOST-Vietnam) is highly appreciated.

Additional information

Funding

The financial support of VLIR-UOS project ZEN2013RIP021 (Belgium) and project 10/2012/HD-NDT (MOST-Vietnam) is highly appreciated.