Characterization and stability of bio-oils upgraded by esterification and olefination.

摘要

Raw bio-oil is produced by fast pyrolysis of biomass. The high level of oxygen content in bio-oil causes negative properties of polymerization over time, high acidity, pungent odor and low heating value relative to petroleum fuels. The objective of this study was to develop and identify upgrading processes to produce a boiler fuel with reduced acid value, reduced polymerization over time and increased higher heating value. By one upgrading method, raw bio-oil was upgraded by esterification over acid catalyst by batch reaction; a second approach was an in-reactor reaction, produced by injecting methanol or 1-butanol with acid catalyst into the pyrolysis vapor stream. An olefination reaction method combined with an esterification reaction was also studied. The resulting fuel produced from in-reactor esterification fuel was compared in terms of physical and chemical properties with esterifed bio-oil produced by the batch method. The olefination reaction was examined in terms of higher heating value, acid value, viscosity, and water content. The influence of reaction conditions such as reaction time, reaction temperature, and catalyst content relative to upgraded bio-oil properties were examined, and optimal conditions were identified. Analysis of variance (ANOVA) and empirical analysis was utilized to analyze the difference in physical and chemical properties between treatment groups.