Influence of reaction conditions on the hydrodeoxygenation of light components in bio‐oil to long‐chain alkanes over Ni/HZSM‐5‐γ‐Al2O3

Abstract

AbstractA modified γ‐Al2O3‐supported nickel‐based Ni/HZSM‐5 catalyst prepared by the impregnation method was characterized by physical adsorption of N2, X‐ray diffraction, temperature‐programmed desorption of ammonia, thermogravimetric analysis, and scanning electron microscopy. The influence of temperature, pressure, flow, and space velocity on the hydrodeoxygenation (HDO) of light components in bio‐oil was studied, and a lifespan test was performed on the Ni/HZSM‐5‐γ‐Al2O3 catalyst. The results showed that at a reaction temperature of 380°C, pressure of 2 MPa, flow rate of 380 ml min−1, and mass space velocity of 0.78 h−1, the hydrocarbon content of the upgraded oil was the highest, reaching 89.49%. Long‐chain alkanes were the main hydrocarbons in the upgraded oil. The results of a lifespan experiment show the good stability of the Ni/HZSM‐5‐γ‐Al2O3 catalyst in the HDO of bio‐oil over 5 h of reaction. The HDO reaction pathway of bio‐oil mainly resulted in conversion into long‐chain alkanes through a condensation reaction, a decarbonylation/decarboxylation reaction and hydrogenation. This study provides a reference for the preparation of high‐quality liquid fuels from biomass. [Correction added on June 18, 2021, after first online publication: 89.47% changed to 89.49%]