Catalytic hydrodeoxygenation of simulated phenolic bio-oil to cycloalkanes and aromatic hydrocarbons over bifunctional metal/acid catalysts of Ni/HBeta, Fe/HBeta and NiFe/HBeta

Bifunctional metal/acid catalysts of 5 wt% Ni/HBeta, 5 wt% Fe/HBeta, 2.5 wt% Ni-2.5 wt% Fe/HBeta (NiFe-5/HBeta) and 5 wt% Ni-5 wt% Fe/HBeta (NiFe-10/HBeta) were used for hydrodeoxygenation (HDO) of a simulated phenolic bio-oil consisting of phenol (50 wt%), o-cresol (25 wt%) and guaiacol (25 wt%). Nickel and iron metals were supported on hydrogen form Beta zeolite (HBeta) under similar ion-exchange conditions. BET surface area and acid sites density of Ni/HBeta, Fe/HBeta, NiFe-5/HBeta and NiFe-10/HBeta were 463, 445, 455, 417 m(2)/g and 0.53, 0.48, 0.50, 0.38 mmol/g, respectively. Cycloalkanes (21.39 wt%) and aromatic hydrocarbons (20.21 wt%) were the dominant hydrocarbons obtained over monometallic catalysts of Ni/HBeta and Fe/HBeta through reactions of hydrogenation and hydrogenolysis, respectively. It was revealed that both hydrogenation and hydrogenolysis mechanisms were effectively proceeded over the bimetallic catalyst of NiFe/HBeta which showed enhanced HDO efficiency compared to monometallic catalysts of Ni/HBeta and Fe/HBeta due to the synergistic effect between the two metals. The effect of reaction temperature on HDO efficiency of NiFe-10/HBeta catalyst was investigated at 220, 260, 300 and 340 degrees C. Maximum catalytic activity and hydrocarbons selectivity was observed at 300 C. Replacement of water with methanol as solvent in HDO of the simulated phenolic bio-oil over NiFe-10/HBeta remarkably reduced the selectivity towards hydrocarbons. (C) 2016 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.