Optimization of biomethane production from pet coke through anaerobic digestion using microbial inoculum and Fe2O3 nanoparticles: A response surface methodology approach
The search for alternative renewable energy sources has mounted interest in biomethane as a viable substitute for fossil fuels. This study explores the anaerobic digestion of petroleum coke, a recalcitrant byproduct of oil refining, enhanced by coal mine-derived microbial inoculum and magnetic iron oxide (Fe2O3) nanoparticles (NPs). The Fe2O3 NPs were obtained through the coprecipitation technique. A central composite design within Response Surface Methodology was employed to optimize three variables; pet coke concentration, inoculum size, and NPs dosage. Scanning electron microscopy results of the synthesized NPs showed quasi-spherical morphology, particle aggregation, and distinct crystalline. X-ray diffraction peaks indicative of spinel-type ferrites, confirming a magnetite-based structure. Analysis of variance results of the linear model present a moderate coefficient of determination (R2 = 0.5799) for the model, indicating its adequacy for prediction. The optimized conditions for biomethane production were determined as follows: Feedstock (Pet coke) concentration of 8 g/L, Inoculum of 8 % (v/v), and 40 mg/L of magnetic iron oxide NPs. Under the optimized conditions, the model predicted a biomethane yield of 33.2%, which closely aligned with the experimentally observed yield of 32%; the difference was not statistically significant (P = 0.158) reliability. Validation experiments substantiated the model reliability. The gas chromatography analysis of the generated gas revealed a methane concentration of 55.86 wt%, thereby illustrating significant bioenergy potential. The integration of microbial consortia and NPs strategies offers a promising alternative for converting industrial residues, such as pet coke into sustainable biofuels.
Rajarathinam R, Yousif M. Optimization of biomethane production from pet coke through anaerobic digestion using microbial inoculum and Fe2O3 nanoparticles: A response surface methodology approach. J Appl Biol Biotech 2025. Article in Press. http://doi.org/10.7324/JABB.2026.265069
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