Biodiesel Synthesis by Ethanolysis of Hura crepitans Seed Oil Unfit for Consumption in Benin

摘要

To reduce fossil fuel dependence and greenhouse gases, biomass energy is in high demand. Hura crepitans (HC) is a widely distributed plant species in Benin. But its seed oils are reputed to be purgative and unfit for consumption. So, we collected the seeds of HC in Agame (South of Benin). They were extracted and the seed oils have been converted into biodiesel. First, the quality indices (acid, peroxide, iodine and saponification) were determined. Then, elementary physicochemical parameters and fuel properties of the extracted oil have been highlighted according to standardised methods. Transesterification parameters of the seed oils (alcohol/oil and catalyst/oil ratios, temperature and yield) were also studied. The fatty acids of vegetable oil and the characteristics of its obtained biodiesel were finally identified. It appears that HC seeds have a lipid potential of 52.54%. Its oil is unsaturated and dominated by linoleic acid (54.13%). The yield of the transesterification reaction is 81.47%. The fuel parameters of the obtained biodiesel are: acidity (0.41%); density at 26°C (0.887); cetane number (54.44) compared to those of HC seed oils: acidity (4.81%), density at 26°C (0.929) and cetane number (44.53). The biodiesel obtained by transesterification with potash has much better parameters that comply with biodiesel standards. These results suggest that biodiesel of HC could be proposed to power Diesel engines without a preheating system.