Hydrodeoxygenation upgrading of pine sawdust bio-oil using zinc metal with zero valency

Hydrodeoxygenation (HDO) is an effective method for bio-oil upgrading. However, the high hydrogen consumption resulted in high bio-oil upgrading cost. In this study, an novel method of hydrogen generation from water for bio-oil HDO was reported. Zinc metal with zero valency was used to generate hydrogen through zinc hydrolysis reaction in the bio-oil HDO process. The effects of different temperatures (20 degrees C, 250 degrees C, 300 degrees C, 350 degrees C, 400 degrees C) on in situ bio-oil HDO was investigated. The results showed that high temperatures resulted in high hydrogen yield that led to promoted HDO activity over zinc metal-based materials. Although 20 degrees C bio-oil HDO process generated the highest oil phase yield at 14.07%, 400 degrees C bio-oil upgrading process produced upgraded bio-oil with highest hydrocarbons content at 68.95%. Physicochemical properties of raw bio-oil improved significantly after bio-oil HDO upgrading at higher temperatures (250 degrees C, 300 degrees C 350 degrees C and 400 degrees C). The pH of upgraded bio-oils (5.70-6.49) increased significantly compared to raw bio-oil (3.24). The higher heating value of upgraded bio-oils (28.67-33.43 MJ/kg) increased significantly compared to raw bio-oil (15.54 MJ/kg), and valuable hydrocarbons content improved significantly from 16.94% in raw bio-oil to 37.86%-68.95% in upgraded bio-oils. (C) 2017 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.