Yield Response from the Catalytic Conversion of Parsley Seed Oil into Biodiesel Using a Heterogeneous and Homogeneous Catalyst

[Image: see text] This research work is focused on the investigation of the optimum condition for parsley seed oil (PSO) trans-esterification using a heterogeneous (CCB) and homogenous catalyst (KOH). The process parameters (alcohol: oil ratio, temperature, and catalyst loading) were varied to examine their effect on the percentage biodiesel yield using a Box–Behnken design embedded with the response surface methodology (RSM). Also, the heterogeneous catalyst was synthesized by calcining waste chicken bones at 900 °C for 4 h. Thereafter, scanning electron microscopy (SEM), X-ray fluorescence (XRF), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analysis were utilized to determine the morphology and elemental composition. Thermogravimetric analysis (TGA) was also adopted to assess the effect of calcination temperature on the prepared catalyst. The characterization analysis revealed the presence of hydroxyapatite as the major component, and the reusability test showed that it exhibited good catalytic performance for PSO transesterification. However, the optimization study revealed that the optimum reaction conditions of 9:1 alcohol: ratio, 60 °C reaction temperature, and 3 wt % catalysts gave 90% biodiesel yield, while the homogenous catalyst (used as the control transesterification experiment) under the same conditions gave an average yield of 96.33%. Gas chromatography–mass spectrometry (GC–MS) was utilized to characterize the produced biodiesel. Furthermore, the fuel characteristics of biodiesel were within the specifications of the ASTM D6751.