INVESTIGATION OF THE SHELF LIFE OF THE OPTIMIZED SHEA NUT BIODIESEL

This study investigates the shelf life of Biodiesel produced from Shea nut oil, a renewable and sustainable feedstock. Biodiesel is prone to oxidation due to its unsaturated fatty acid content. In the current work an attempt was made to produce biodiesel from Shea nut oil, due to its high Free Fatty Acid content, Shea nut oil was processed in two steps: Esterification and Transesterification. 500g of Shea nut oil was esterified with 25wt% of methanol to oil ratio (125grams) using 1.0wt% H2SO4(5grams) as catalyst constant temperature 60°c for 1.5hours Esterification reaction which reduced the free fatty acid to 0.46% the acid value of 1.86mg KOH/g indicating a low level of of acidity. The properties of the produced biodiesel were very similar and in line with ASTM Standards. After optimizing the process for biodiesel production, with four key parameters were analysed; catalyst loadings at around 6.05, reaction time 75.95 minutes, temperature 43.81°c, produced biodiesel yield of 91.45%. Biodiesel oxidizes, forming peroxides and other degredation products that degrade fuel quality over time. This study examined the oxidation stability using the Rancimat method analysis and oxidation stability times of the biodiesel with and without antioxidants at week 0, week 2 week 4, week 6, week 8 were (4.2, 4.2, 4.2, 3.95, 3.7) hours for inhibited and (180, 160, 140, 120, 100) munites for uninhibited respectively. The WPO biodiesel production was optimized using the Design Expert version 13.0.6. The optimization process carried out was performed using the response surface methodology (RMS). The reaction temperature (30 to 90°c), reaction time of (15 to 120 minutes), and catalyst loadings of (1 to 10 wt%). Were the parameters used and a biodiesel yield of 130.06% was obtained.