Catalytic Conversion of Bio-Oil to Oxygen-Containing Fuels by Acid-Catalyzed Reaction with Olefins and Alcohols over Silica Sulfuric Acid

• Published in: Energies (Basel) Vol. 6; no. 9; pp. 4531 - 4550
• Main Authors: Zhang, Zhijun, Sui, Shujuan, Wang, Fengqiang, Wang, Qingwen, Pittman, Charles
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.09.2013
• Subjects: Alcohol; Biomass; Catalytic cracking; Chromatography; Ethanol; Fourier transforms; Mass spectrometry; NMR; Nuclear magnetic resonance; olefin; oxygen-containing fuels; Phenols; real bio-oil upgrading; Scientific imaging; silica sulfuric acid; Sulfuric acid; Zeolites; United States > US; Mississippi
• ISSN: 1996-1073; 1996-1073
• DOI: 10.3390/en6094531

Crude bio-oil from pine chip fast pyrolysis was upgraded with olefins (1-octene, cyclohexene, 1,7-octadiene, and 2,4,4-trimethylpentene) plus 1-butanol (iso-butanol, t-butanol and ethanol) at 120 °C using a silica sulfuric acid (SSA) catalyst that possesses a good catalytic activity and stability. Gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (1H-NMR) analysis showed that upgrading sharply increased ester content and decreased the amounts of levoglucosan, phenols, polyhydric alcohols and carboxylic acids. Upgrading lowered acidity (pH value rose from 2.5 to >3.5), removed the unpleasant odor and increased hydrocarbon solubility. Water content dramatically decreased from 37.2% to about 7.0% and the heating value increased from 12.6 MJ·kg−1 to about 31.9 MJ·kg−1. This work has proved that bio-oil upgrading with a primary olefin plus 1-butanol is a feasible route where all the original heating value of the bio-oil plus the added olefin and alcohol are present in the resulting fuel.