Hydrodeoxygenation of phenols, acids, and ketones as model bio-oil for hydrocarbon fuel over Ni-based catalysts modified by Al, La and Ga

The large-scale application of bio-oil has been restricted due to its high O content, strong acidity and low heat value. Therefore, the hydrodeoxygenation (HDO) of phenols, acids, and ketones as bio-oil model compounds for hydrocarbon fuel via Ni-based catalysts modified by metal oxides (Al, La and Ga) was investigated. The results showed that the hydrocarbon content was over 70.65% when the mixed supported catalysts Ni/HZSM-5-gamma-Al2O3, Ni/HBeta-La2O3 and Ni/HBeta-Ga2O3 were used for the HDO of guaiacol (GUA). Cyclic hydrocarbons and aromatic hydrocarbons were the main products. Among these catalysts, Ni/HZSM-5-gamma-Al2O3 was the most effective in the HDO of acetic acid. The conversion and hydrocarbon content were 100.00% and 88.62%, respectively. Long-chain alkanes were the main components of the upgraded liquid. Ni/HZSM-5-gamma-Al2O3 was beneficial for the HDO of hydroxyacetone with 100.00% conversion, 80.30% hydrocarbon content and 48.67% yield. The HDO pathways of GUA, acetic acid and hydroxyacetone were as follows: 1) GUA was mainly converted into benzene and its derivatives by transmethylation, isomerization and hydrogenation (HYD). 2) Acetic acid was converted to long-chain alkanes by HYD, self-condensation, saturated HYD and isomerization. 3) Hydroxyacetone was converted into long-chain alkanes by HYD, self-condensation, demethylation, aldol condensation and saturated HYD. This work provides basic data for obtaining renewable hydrocarbon fuel from biomass via HDO with a low-cost catalyst. (C) 2019 Published by Elsevier Ltd.