Title : Production of sub-tropical green diesel containing abundant i-C15 & i-C16 from catalytic hydrodeoxygenation-hydroisomerization of used cooking oil using NiMo/?-Al2O3 and Pt/ZSM-48
Abstract:
Hydrodeoxygenation (HDO) and Hydroisomerization (HI) are applied in fuel processing technology to convert vegetable oil into green diesel which has a fog number and a pour number below °C with a metal- based catalyst. The main challenges for this process are feedstock, catalyst preparation, and the production of oxygen-free diesel fuel. This study aims to synthesize the NiMo catalyst embedded in binary oxide Alumina and ZSM-48 and evaluate its catalytic activity for hydrodeoxygenation and hydroisomerization of used cooking oil (UCO) to green diesel. NiMo/Al2O3 and Pt/ZSM-48 were synthesized by wet impregnation, and UCO hydrodeoxygenation was carried out using a continuous flow reactor. The catalysts were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy - energy dispersive X-ray spectroscopy (SEM-EDS), and N2 adsorption-desorption isotherm analysis. Gas chromatography analysis - distillation simulation spectrometry (GCSimDist) showed the formation of n-C16 and n-C18 hydrocarbon frameworks resulting from the use of NiMo/Al2O3-P with a selectivity of 98.8% after 16 hours of reaction. The further stages of the HI reaction using Pt/ZSM-48 catalyst reduced n-C18 levels and increased i-C15 and i-C16 levels with selectivity of 88.96% and 95.57%. The NiMo/Al2O3 and Pt/ZSM- 48 catalysts produced oxygen-free green diesel (i-C14-i-C18) enriched with i-C15 & i-C16 hydrocarbons. Both catalysts show promising hydrodeoxygenation & hydroisomerization activities through the hydrodecarboxylation pathway and branched framework arrangement.
