Valorization of Bambusa striata shavings into functional superparamagnetic material and its application in biodiesel production: Response surface optimization, kinetics, thermodynamics and economic assessment

Abstract

Herein, a novel highly porous biomass-based (Bambusa vulgaris striata) magnetic solid acid catalyst was developed for the first time via simultaneous activation and magnetization followed by acid functionalization. The sulfonated magnetic porous carbon was utilized as a catalyst for transesterifying Jatropha curcas oil (JCO) to biodiesel under microwave irradiation. The synthesized catalyst was extensively characterized using VSM, XRD, FTIR, SEM, EDS, TGA, XPS, Raman spectroscopy, and AFM techniques. Through Response Surface Methodology (RSM), a maximal biodiesel yield of 98.8% was achieved over optimal optimal parametric states (catalyst loading 8 wt. %, MOMR 24:1, 50 min, 80 °C). NMR confirmed JCO biodiesel formation with a FAME content of 98.04%, and GCMS provided insight into its chemical composition. A pseudo-first-order kinetic study revealed an activation energy (Ea) of 28.734 kJ mol1. Thermodynamic analysis showed endothermic and non-spontaneous behavior with ΔH#, ΔS#, and ΔG# values of 25.928 kJ mol1, -0.193 kJ mol1 K1, and 94.251 kJ mol1, respectively. The catalyst displayed good reusability, easy recoverability, and stability, maintaining 75.4% oil conversion even after ten consecutive cycles. Life cycle cost analysis (LCCA) estimates biodiesel production cost of $0.60 per liter, emphasizing high commercial viability.