Biodiesel from Jojoba oil-wax: Transesterification with methanol and properties as a fuel

The Jojoba oil-wax is extracted from the seeds of the Jojoba (Simmondsia chinensis Link Schneider), a perennial shrub that grows in semi desert areas in some parts of the world. The main uses of Jojoba oil-wax are in the cosmetics and pharmaceutical industry, but new uses could arise related to the search of new energetic crops. This paper summarizes a process to convert the Jojoba oil-wax to biodiesel by transesterification with methanol, catalysed with sodium methoxide (1 wt% of the oil). The transesterification reaction has been carried out in an autoclave at 60 °C, with a molar ratio methanol/oil 7.5:1, and vigorous stirring (600 rpm), reaching a quantitative conversion of the oil after 4 h. The separation of the fatty acid methyl esters (the fraction rich in FAME, 79% FAME mixture; 21% fatty alcohols; 51% of methyl cis-11-eicosenoate) from the fatty alcohols rich fraction (72% fatty alcohols; 28% FAME mixture; 26% of cis-11-eicosen-1-ol, 36% of cis-13-docosen-1-ol) has been accomplished in a single crystallization step at low temperature (−18 °C) from low boiling point petroleum ether. The fraction rich in FAME has a density (at 15 °C), a kinematic viscosity (at 40 °C), a cold filter plugging point and a high calorific value in the range of the European standard for biodiesel (EN 14214).