Hydrodeoxygenation of methyl laurate over the sulfur-free Ni/γ-Al2O3 catalysts

Abstract

A series of sulfur-free Ni/γ-Al2O3 catalysts with different metal Ni loading amount were prepared by impregnation method. The prepared catalysts and corresponding precursors were investigated through XRD, BET, H2-TPD, and H2-TPR analysis methods. The effect of Ni loading on catalytic performance of Ni/γ-Al2O3 catalysts was evaluated by methyl laurate catalytic hydrodeoxygenation (HDO). Results indicate that the catalytic HDO performance of the prepared Ni/γ-Al2O3 catalysts was directly related to hydrogen storage properties, hydrogen desorption properties, dispersion of the active component Ni, and so on. The 10 wt.% Ni/γ-Al2O3 catalyst exhibits the best HDO performance, and the methyl laurate conversion can reach 91.1% when the reaction temperature is 400 °C and pressure is 2 MPa. The HDO products are alkanes, such as C<10, C10, C11, C12 alkane, C12 alcohol, and C12 acid, especially. The main product C11 alkane with one carbon less is formed by decarbonylation/decarboxylation, and selectivity can reach 68.6%. The effects of reaction conditions on HDO reaction of oils were studied, for example, reaction pressure and H2/Oil ratio. The catalyst retains comparable activity upon regeneration through calcinations and H2 reduction.