Analysis of biodiesel from the waste of sunflower cooking oil produced in Uganda

Abstract

Biodiesel is a product from the transesterification of alcohol and vegetable oils. It is a greener alternative to petroleum diesel. Waste Cooking sunflower Oil produced in Uganda was used for biodiesel production in this study. The biodiesel was produced by transesterification process using potassium hydroxide as a catalyst. At optimal reaction conditions ( 1:5, 1hr, 60OC and 1.5%wt), a maximum biodiesel yield of 88% was achieved. Biodiesel obtained was light yellow in color. The physicochemical properties of biodiesel such as density, acid value, cetane number and iodine value were analysed, which were found to be 1.196 g/cm³, 2.85 mgKOH/g, 81.5 and 4.19 I2g/100g respectively. These properties were compared with American Society for Testing and Materials (ASTM). The acid value and density were found to deviate from ASTM limits. Fourier transform infrared spectroscopy (FTIR) spectra of the biodiesel showed carbonyl group of an ester at 1738 cm-1 . The UV spectrum confirmed the presence of conjugated aldehydes such as 2,4 decadienal and unconjugated methylesters. The GC analysis showed that the biodiesel contained mainly of pentadecanoic acid methylesters. It also confirmed the presence of oxidation compounds such as aldehydes and ketones. In conclusion, this study presents the utilisation of waste sunflower cooking oil as a potential feedstock for biodiesel production in Uganda.