Hazardous waste management of novel non-edible Platycladus orientalis seed oil via recyclable yttria-based phyto-nanocatalyst: A practical approach towards sustainable bioenergy conversion

In current scenario of rising issues of economic crises, ecotoxicity and waste management, the search of novel, waste and non-food biomass for green energy production has become indispensable. This study is concerned with Platycladus orientalis, a novel feedstock with a seed oil concentration of 28 % (w/w), optimized via simulation-based response surface methodology (RSM) for biodiesel production. To enhance catalytic activity during transesterification, novel Yttria-based green metallic oxide, a phyto-nanocatalyst, was synthesized using Platycladus orientalis dried seed cones aqueous extract. The Yttria-based phytonanocatalyst was characterized using FTIR, XRD, SEM, and EDX that confirmed its structural and elemental composition with 12 nm nano-size and demonstrated the high catalytic efficiency. The optimal conditions for biodiesel synthesis were identified as methanol-to-oil ratio (7:1), catalyst concentration (0.14 wt%), reaction time (105 min), and reaction temperature (80 °C) with remarkable biodiesel yield (96 %). The reusability of the Yttria-based green nanoparticles was assessed over six reaction cycles. Methyl ester formation was validated through FTIR, GC–MS, and NMR analyses. The fuel properties were found to fall within the range recommended by the international biodiesel standards i.e. flash point of 90 °C, density of 0.614 kg/L, viscosity of 4.21 cSt, pour point of −8 °C, cloud point of −10 °C, total acid number of 0.124 mg KOH/g and sulfur content of 0.00002 wt%. With its prolific seed production and wide distribution, Platycladus orientalis is a highly recommendable species for sustainable and eco-friendly biodiesel production. This study contributes to the evolving field of green catalysis, offering a viable solution to environmental issues and waste management challenges in the biodiesel industry.