Transesterification of camelina sativa oil with supercritical alcohol mixtures

The transesterification of camelina sativa oil with methanol-1-butanol, and ethanol-1-butanol alcohol mixtures under supercritical conditions have been studied in order to maximize biodiesel yield and improve biodiesel quality. The influence of the variation of the molar ratio of methanol-1-butanol and ethanol-1-butanol from 1:0, 3:1, 2:1, 1:1, 1:2, to 0:1 on the yield of free fatty methyl esters/free fatty ethanol esters-free fatty acid butyl esters, the composition of the biodiesel blend mixtures, and the physical properties of the biodiesel have been investigated at the reaction temperature of 290 °C, reaction time of 30 min, and the initial reaction pressure of 500 psi. A maximum yield of 86.14 wt% for free fatty acid methyl esters-free fatty acid butyl esters with the optimum cold property can be obtained at the molar ratio of methanol-1-butanol of 0.5-0.9. Also, a maximum yield of 85.60 wt% for free fatty ethyl esters-free fatty butyl esters with the lowest pour point can be achieved at the molar ratio of ethanol-1-butanol in the range of 0.5-0.7.