World Congress on Engineering and Computer Science, WCECS 2012, San Francisco, CA, United States Of America, 24 - 26 October 2012, vol.247 LNEE, pp.651-664
Transesterification reaction of the new generating biofuel resource, microalgae was conducted. In order to evaluate the effects of reaction variables such as catalyst type (KOH, NaOH), catalyst amount (1-1.5 % w/w), oil:methanol molar ratio (1:6-1:10), and time (5-20 min) on the methyl ester content of biodiesel. Suitable transesterification reaction conditions were determined as 65 C, 1 wt % catalyst amount, 5 min, 1:8 microalgae oil:methanol molar ratio using microwave heating system for both homogeneous catalysts. At these conditions fatty acid methyl ester content was determined as 96.54 and 96.82 % for KOH and NaOH, respectively. The results show that microwave heating has effectively reduced the reaction time from 210 min (for conventional heating) to 5 min. Electric energy consumption for microwave heating in this accelerated transesterification reaction was only 28.22 % of estimated minimum heat energy demand. Heterogeneous base catalyst, KOH/Al2O3, was also used to investigate the reaction activity due to growing interest in transesterification. According to slow reaction rate of heterogeneously catalyzed reactions, time, oil:methanol molar ratio and catalyst amount were increased as 35 min, 1:12 and 3 % w/w, respectively. Biodiesel conversion was found to be 97.79 % at these conditions. © 2014 Springer Science+Business Media Dordrecht.