Abstract
<jats:title>Abstract</jats:title> <jats:p> Exploring sustainable and renewable solutions such as biodiesel has gained tremendous attention owing to their environmentally conscious nature and carbon neutrality, contributing to a healthier planet. The present research investigates the underutilized coniferous seeds of <jats:italic>Picea smithiana</jats:italic> as novel feedstock for synthesizing biodiesel, owing to their highest seed oil content (46.57% w/w). The study endeavors the smart waste valorization strategy using <jats:italic>P. smithiana</jats:italic> seed husk as a starting material for synthesizing highly active, recyclable BaO nanocatalyst, via the wet impregnation method. This dual zero‐waste valorization approach of coniferous seeds has never been explored before. The green nanocatalyst exhibits exceptional performance in transforming <jats:italic>P. smithiana</jats:italic> seed oil to biodiesel, yielding 95.6% under model conditions of methanol‐to‐oil 1:15, catalyst 0.12 wt%, reaction time of 145 min at 140 °C temperature. The synthesized nanocatalyst was investigated via SEM, FTIR, XRD, EDX, and Zeta potential. Characterization showed an average particle size of 47.7 nm. Likewise, the chemical transformation of coniferous seed oil into biodiesel was assessed by GC–MS and Nuclear Magnetic resonance (H‐ and C‐NMR). Additionally, the synthesized nanocatalyst exhibits excellent catalytic activity and reusability up to six runs, with a 95% to 85% biodiesel yield confirming sustained catalytic performance. GC–MS spectral analysis validated octadecanoic acid methyl ester as the major entity with a yield of 93.5%. Being characterized by its massive seed production and world geographical coverage, <jats:italic>P. smithiana</jats:italic> has high scalability potential for biodiesel production. Future research efforts should center on techno‐economic feasibility, life cycle analysis, and integral <jats:italic>P. smithiana</jats:italic> ‐based biorefinery design. </jats:p>