Application of spinel Type NixZn1-xFe2O4 magnetic nanocatalysts for biodiesel production from neem seed oil: Catalytic performance evaluation and optimization

This paper aims to synthesize NixZn(1-x)Fe(2)O(4) (0 <x < 0.5) magnetic nanocatalysts for biodiesel production using neem oil esterification. X-ray diffraction (XRD), a vibrating-sample magnetometer (VSM), field emission scanning electron microscopy (FESEM), and Brunauer-Emmett-Teller (BET) analysis were used to analyze the physicochemical properties of the nanocatalysts. Furthermore, the effects of the methanol-oil molar ratio (3:1-30:1), reaction temperature (40-100 degrees C), nanocatalyst loading (1-5 wt%), and the reaction time (10-90 min) on the biodiesel yield were investigated in Design-Expert. Numerical optimization was carried out to optimize the operating parameters through a central composite design (CCD) approach. The biodiesel yield was maximized to 93% at a reaction time of 50 min, a methanol-oil molar ratio of 16.5:1 a catalyst mass fraction of 3%, and a reaction temperature 70 degrees C. The optimized nanocatalyst was subjected to ten reuse cycles, with the first five cycles showing superb efficiency (>88%).