Sustainable biodiesel production from waste cooking oil utilizing waste ostrich (Struthio camelus) bones derived heterogeneous catalyst

Abstract

The present work espouses a zero-waste approach for relying on indigenous waste resources to deliver green and sustainable biofuel. This investigation reports biodiesel production from waste cooking oils (WCO) via cheap heterogeneous catalyst obtained from waste Ostrich (Struthio camelus) bones for the first-time. The synthesized catalyst was characterized by Thermogravimetric analysis/differential scanning calorimetry (TGA/DSC), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), X-ray fluorescence (XRF), Hammett indicator method and surface area calculations. The powdered ostrich bones were calcined at different temperatures, ranging from 600 to 1000 °C. Upon temperature rise, sharp peaks of hydroxyapatite (HAp) appeared as observed by XRD. The reaction parameters have been optimized in presence of the synthesized catalyst to maximize biodiesel yield. The optimum biodiesel yield of 90.56% was attained at methanol/oil ratio 15/1, process temperature 60 °C, catalyst loading 5 wt% within reaction duration of 4 h. It concludes that hydroxyapatite (HAp) derived from ostrich bones showed good catalytic performance to produce biodiesel from WCO. The synthesized catalyst sustained adequate catalytic activity even after being repeatedly recycled four times, which infers low-cost biodiesel production opportunities. Furthermore, an integrated waste oil/bone collection approach is recommended for the effective utilization of indigenous waste to produce biodiesel.