The conventional alkali catalyzed transesterification also suffers mass transfer resistance. It was also shown by Hou et al.  that initially the reaction rate is very slow due to mass transfer limitations between methanol and oil phase. Peterson et al.  has studied the effect of stirrer speed on the transesterification of vegetable oil with alcohol. Ataya et al.  and Ma et al.  has demonstrated the importance of mixing in the Biotin Hydrazide catalyzed methanolysis of beef tallow. The effect of the stirring intensity of the transesterification of cotton seed oil using several catalysts has been analyzed by Rashid et al. . They have shown that beyond an optimum stirrer speed production level decreases. Roy et al.  has shown the effect of stirrer rotation on mass transfer in biodiesel production process. Thus, transesterification reaction for biodiesel production is initially mass transfer limited because the two reactants are immiscible with each other. In addition to that, the glycerol phase separates together with most of the catalyst .