Evaluation and screening of potential non-food biodiesel plants from native wild species of Northwestern China

The fatty acid (FA) composition of plant oil prepared for biodiesel has been found to affect the properties of the fuel. This work aimed to evaluate the characteristics of plant oil resources in Northwestern China and to find some suitable plant species for biodiesel production using criteria from FA profile indexes. Eighteen (18) plant species were investigated: five herbaceous annuals, five shrubs and eight trees. Physicochemical properties of the collected samples were tested, including the oil content, acid value, iodine value and vegetable oil FA composition. According to biodiesel standards EN 14214 and ASTM D6751 and related references, nine out of the 18 species analyzed were potentially suitable for biodiesel production. All of the species selected as being optimal for biodiesel production were shrubs or trees. Using multi-comparison analysis, FA compositions were compared and found to be different enough that the 18 species could be classified based on this property, beyond the plant life-form classification. Therefore, triangular graphs based on FA composition were built in order to screen for the optimal plant oils for biodiesel production. These analyses indicated that wild tree resources can be used as alternative feedstocks in Northwestern China; the species Amygdalus persica L. and Decaisnea insignis (Griff.) Hook. f. and Thoms. were found to be the best for biodiesel production in this study.