Abstract
This study compared the reactivity of microalgal oils in supercritical methanol (SCM) to produce fatty acid methyl ester (FAME). The microalgal oils were obtained by solvent extraction or hydrothermal liquefaction methods. Thirty minutes are found to be best condition to obtain largest amount of biodiesel in both of these methods. However, the longer reaction time (> 30 min) induced decomposition of FAME produced from solvent extracted oil. HTL oil gave high conversion rate of 74.1% at relatively mild condition (320 ℃, 13 MPa, 30 min, methanol: oil=21:1 mol/mol) in transesterication reaction in SCM. Solvent extracted oil gave conversion rate of 69.1% at 320 ℃, 13 MPa, 30 min, methanol: oil=42:1 mol/mol).
