Integrated phyto-bio metal catalysis for sustainable biodiesel production from Tamarix aphylla floral oil using green-synthesized Bi₂O₃ nanocatalyst

The urgent need for sustainability and inedible feedstock fueled the innovation in the biodiesel industry. This study demonstrates the waste-to-fuel approach by introducing Tamarix aphylla floral oil as a novel, non-edible feedstock and Jacaranda mimosifolia -leaf-mediated bismuth oxide cat for effective biodiesel production. The floral oil extracted from this resilient halophytic plant exhibited a low free fatty acid content of 0.28 wt% and a high oil content of 29 wt%, making it suitable for direct transesterification. The photosynthesized Bi 2 O 3 nano catalyst showed a highly crystalline α-Bi 2 O 3 phase with a porous morphology, abundant active sites, an average crystallite size of 28.4 nm, and maintained approximately 88% yield after six reuse cycles. Response surface methodology (RSM)optimization yielded a maximum biodiesel output of 91.55% under optimized condition: 10:1 methanol-to-oil molar ratio, 0.6% wt% catalyst loading, 70°C, and 110 min. FT-IR and NMR (¹H & ¹³C) analyses confirmed that the resultant biodiesel consisted of fatty acid methyl esters (FAMEs). This work develops a novel, environmentally friendly synthesis method called Phyto-Bio metal Catalysis that utilizes waste floral biomass and green nano catalysis. A strategic pathway for future scale-up studies outlined, emphasizing catalyst durability, reactor intensification, and preliminary sustainability considerations. In line with the objectives of the global circular bioeconomy, this integrated approach offers a workable strategy for sustainable energy generation on marginal lands.