Biodiesel production through direct transesterification of microalgae with alcohol via ultrasonic wave

摘要

A one-step extraction/transesterification process was developed to directly convert microalgae into biodiesel in the presence of catalyst, KOH using ultrasonic irradiation. The influences of various parameters on the transesterification reaction, including the reaction time, temperature, catalyst concentration, methanol to microalgae mass ratio and ultrasonic power, were investigated. And the optimum conditions for the transesterification process have been obtained as mass ratio of methanol to microalgae as 4:1, catalyst concentration of 7wt.%, temperature as 70°C and ultrasonic power as 100W with an irradiation time of 30 min by orthogonal experiments L9(34)．Under these conditions, the conversion of fatty acid methyl esters was up to 4.0%.