Abstract:

A kind of solid base catalyst was prepared by means of the isovolumetric impregnation,and the product was used to catalyze the transesterification of Jatropha curcas oil to prepare biodiesel. The influences of carrier,active component and carrier dryness on the properties of the solid base catalyst were analyzed,and the optimal conditions for preparing the catalyst were obtained. Moreover,the effects of ultrasonic radiation,methanol-to-oil molar
ratio,catalyst dosage and reaction time on the conversion of methyl ester were discussed,and the kinetics of transesterification under mechanical agitation and ultrasonic irradiation were explored,with the corresponding kinetic equations being obtained. The results show that the catalyst is of the highest performance when it is prepared at 300℃ by a 3-h drying,with NaX and KOH ( with a loading amount of 15%) respectively as the carrier and the active component,that the conversion of methyl ester reaches 95. 8% when the transesterification is enhanced with 40Hz and 90W ultrasonic at 32℃ for 60min and when the methanol-to-oil molar ratio and the catalyst dosage are respectively 8:1 and 2%,that the reaction rate constant under ultrasonic irradiation is 3. 79 times than under mechanical agitation,and that the reaction orders under ultrasonic irradiation and mechanical agitation are 0. 4889 and 0. 6431,respectively.

Key words: ultrasonic, Jatropha curcas oil, solid base catalyst, transesterification, biodiesel