Sinapis alba seed as a prospective biodiesel source

Seed processing and oil pre-treatment were optimised to improve the yield and quality of biodiesel obtained from Sinapis alba. By using solvent extraction or mechanical pressing followed by solvent extraction, an oil extraction yield greater than 41 wt.% and a de-oiled cake with less than 2 wt.% of oil could be obtained. The oil characterisation showed that erucic acid was the most predominant fatty acid in the oil composition (>50 wt.%). A high phosphorous content (>36 mg/kg) and acid value (>1.5 mg KOH/g) were obtained. To obtain a biodiesel with a high methyl ester content, it was necessary to carry out an oil refining process (acid degumming and chemical de-acidification) followed by a standard transesterification with methanol and sodium methoxide as a catalyst. Finally, the quality of the purified biodiesel was tested according to the EN 14214 and ASTM D6751 standards. The results of this work revealed the possibility of using the oil from Sinapis alba seeds as a suitable source for biodiesel.

► Seed processing and oil pretreatment were optimized to improve biodiesel yield obtained from Sinapis alba.
► Erucic acid was the most predominant fatty acid in the oil composition, not being considered suitable for human consumption.
► A high phosphorous content and acid value were observed in the crude oil, being necessary a refining process.
► Purified biodiesel met all the parameters specified by the standards except kinematic viscosity and oxidation stability.