Upgrading of soybean meal-derived bio-oil via hydrodeoxygenation over [formula omitted]-Al2O3-supported monometallic and bimetallic catalysts

Abstract

The characteristics of bio-oil derived from soybean meal were upgraded by the hydrodeoxygenation (HDO) over monometallic and bimetallic catalysts. The heating value of the bio-oil remained low due to its high oxygen content. To minimize oxygenated compounds in the bio-oil, the HDO was performed in a high pressure reactor at 300 °C under hydrogen pressure. The catalysts utilized in this reaction were Ni/γ-Al2O3 and Ni-Co/γ-Al2O3 produced using an incipient wetness impregnation approach. Several aspects influencing bio-oil upgrading were investigated, including catalyst type, nickel and cobalt ratio, catalyst amount, and reaction time. When compared to the oil before upgrading, the bio-oil after HDO with all catalysts had a better quality with reduced oxygen and greater carbon contents. The Ni/γ-Al2O3 catalyst was more efficient than the bimetallic catalysts in terms of reducing oxygen content and increasing the heating value of the pyrolysis oil. The pyrolysis oil with the lowest oxygen content was produced by the 1% nickel on alumina catalyst, resulting in the high heating value (HHV) of 37.4 MJ/kg. The catalyst amount of 2.5 %wt and the reaction time of 1 h were the suitable conditions for the HDO of soybean meal-derived bio-oil.