Two stages upgrading of bio‑oil through esterification and hydrodeoxygenation reactions using Fe2O3‑CoO supported catalyst

Bio-oil contains many oxygenated compounds, as well as high acid and water content, which can reduce the stability of its components and have poor overall physicochemical properties. In this study, the quality of bio-oil produced from the pyrolysis of oil palm fronds was enhanced through a hydrodeoxygenation (HDO) reaction that was preceded by esterification as a pre-treatment. The catalyst used in the HDO reaction is mixed metal oxide (Fe2O3-CoO) anchored within zeolite mordenite (Fe2O3-CoO/Mor). The catalysts were characterized using XRD, SEM-EDX, and BET methods. The presence of metal oxides on the surface of mordenite increases the activity of the catalyst in producing liquid products while reducing the formation of coke. Upgrading of bio-oil has improved the physicochemical properties of bio-oil compared to the one-stage upgrading process. The analysis of product showed that the C and H content increased from 11.5 to 23.5 wt% and from 9.76 to 11.2 wt%, respectively. On the other hand, the O content decreased from 78.7 to 65.2 wt% with a degree of deoxygenation of 59.8%. Moreover, higher heating value (HHV) of the bio-oil increased by 38% from 11.6 to 16.0 MJ/kg.