AcknowledgementsThe authors gratefully acknowledge the financial

AcknowledgementsThe authors gratefully acknowledge the financial support of Natural Science Fund of China (Grant Nos.: 51390490 and 11132008) and Zhejiang Province Science and Technology Innovation Team Project (2013TD18).
Appendix A. Supplementary material
Supplementary data 1.
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Biodiesel; Jatropha Curcas oil; Transesterification; Catalyst; Stirring effect; Mass transfer
1. Introduction
Transesterification or alcoholysis Sulfo-NHS-Biotin commonly employed to convert vegetable oil to biodiesel in the presence of catalyst. A number of processes have been developed for biodiesel production involving either chemical catalyst like acids, bases, both liquid and heterogeneous or biological catalyst like immobilized or free enzyme [4], [5], [6], [7], [8] and [9]. There are many research articles where alkaline transesterification for biodiesel production is investigated [10], [11] and [12], where raw material with a high water or free fatty acid (FFA) content needs pretreatment with an 'Sulfo-NHS-Biotin' acidic catalyst in order to esterify FFA [13] and [14]. Pretreatment is necessary to reduce soap formation during the reaction and to simplify the extensive action for separation of biodiesel and glycerol together with removal of catalyst and alkaline waste water [10] and [15].