Conventional production of biodiesel employs the use of alkaline catalysts because they are cheaper and less corrosive, and they use minimal energy when compared to other acidic catalysts. Heterogeneous catalysts have also shown significant effects on biodiesel production with its ease of recovery and reusability. Three reaction variables-temperature, time, and molar ratio of alcohol to oil-were optimized for biodiesel production from milk bush oil using snail shell as a catalyst. The catalyst was prepared by calcinating waste giant African land snail in an electric oven for 3.5 hours at 900°C. Also, a control transesterification experiment was carried out using potassium hydroxide (KOH) as a catalyst. Catalyst concentrations of 3.0 wt % of calcined snail shell (CSS) and KOH were used for the transesterification of the oil. A response surface analysis of biodiesel production using CSS as a catalyst showed that all reaction variables were significant. Biodiesel yield of 81% was recorded experimentally as the highest yield when temperature, reaction time, and alcohol-to-oil ratio were 65°C, 2 hours, and 9:1, respectively. An average yield of 94.33% was obtained at these same reaction conditions when KOH was used as a catalyst.

The cost and difficulty in the preparation of synthetic heterogeneous base catalysts is the main barrier to their use. Today, the majority of these catalysts are derived from biomass resources. This study aimed at developing and characterizing these catalysts from three biogenic residues for biodiesel production without catalyst support. The EDS indicated the variation of Na, K, Mg, and Ca, having aggregates of 67.45, 83.15, and 76.85 % in calcined‐ periwinkle shell‐ash (CPWSA), ‐melon seed‐husk ash (CMSHA) and ‐locust bean pod ash (CLBPA), respectively. XRD revealed the presence of sodium oxide (Na2O), calcium oxide (CaO), potassium oxide (K2O), and magnesium oxide (MgO) in the catalysts at 800 °C. The FTIR showed the presence of C=O, C−H, and O−H bonds in the catalyst samples. The basicity values of CPWSA, CMSHA, and CLBPA are 11.65, 10.41, and 11.62, respectively. The developed catalysts were used to synthesize biodiesel from palm kernel oil.

No abstract

No abstract