Ultrasound-assisted synthesis of biodiesel from palm fatty acid distillate

Abstract

The present work aims at exploiting palm fatty acid distillate as a starting raw material for synthesis of biodiesel with the aim of reducing the cost of production. Esterification of palm fatty acid distillate (PFAD) with methanol in the presence of concentrated H₂SO₄ as a catalyst has been investigated in the presence of ultrasonic irradiations at 22 kHz frequency and 120 W as supplied power dissipation. The effect of different operating parameters such as molar ratio of reactants, catalyst quantity, and operating temperature have been studied with the aim of process optimization. It has been observed that ultrasound significantly enhances the rate of reaction and also the extent of equilibrium conversion. A certain degree of conversion attributed to heterogeneity of the system, which adds to mass transfer resistances under conventional approach, appears to get eliminated due to ultrasound. Conversion levels of more than 90% have been observed with the use of ultrasound in about 150 min under ambient operating conditions.