Unveiling the efficacy of TiO2-mediated calcareous nanocatalyst towards cost-effective biodiesel synthesis

The global energy matrix, predominantly fuelled by fossil sources constituting 85 % of consumption, confronts critical ecological ramifications, including prodigious greenhouse gas emissions precipitating climate change and pervasive pollution. This probe elucidates the mechanistic proficiency and economic viability of TiO₂-augmented CaO-derived nano-catalysts for biodiesel production from Brassica napus oil. Synthesized via sol-gel techniques with variable precursor concentrations and calcination temperatures, these nano-catalysts were rigorously characterized using UV spectroscopy, FTIR, SEM, XRD, zeta potential, EDAX, and particle size analysis. The utmost biodiesel yield of 95.87 % was attained utilizing response surface methodology under a 2.25-h reaction interval with a 5 % catalyst weight, a 1:12 oil-to-methanol ratio, and a temperature of 60 °C. Thermodynamic and kinetic examinations revealed the transesterification reaction to be endothermic following pseudo-first-order kinetics. The catalyst exhibited notable reusability, maintaining a conversion efficiency of 76.86 % after five consecutive cycles. The characteristics of the produced biodiesel met the required standards, with production costs calculated at $0.78 per litre and $7.0 per kilogram of TiO₂-CaO catalyst, underscoring its economic feasibility. This research accentuates the TiO₂-CaO nanocatalyst's potential in mitigating the environmental and economic detriments associated with fossil fuel dependency. Finally, the study provided future perspectives by identifying gaps highlighted in recent bibliometric analyses of the reported research.