Study of bio-oil properties and ageing through fractionation and ternary mixtures with the heavy fraction as the main component

Bio-oil produced by fast pyrolysis of eucalyptus sawdust in a bubbling fluidised bed reactor with temperature between 450 and 550 degrees C was divided into two fractions: heavy bio-oil (HBO) and light bio-oil (LBO). These fractions were mixed with ethanol (EtOH) in order to obtain seven ternary mixtures. These mixtures were characterised according to the following properties: viscosity, lower heating value (LHV), higher heating value (HHV), water content, solids content, acidity, flash point, pour point, density and ultimate analysis. Fractions also had their properties determined. Viscosity, due to its peculiarity, was monitored until 90 days and each mixture had its viscosity profile as a function of time and temperature. Ultimate analysis, heating values, acidity and water content were determined at two different moments to provide an understanding into mixtures ageing. Some properties were analysed through the ternary diagram. Overall, mixtures presented good fuel characteristics with lower water content and acidity and higher heating values and carbon content than typical bio-oil. Nevertheless, choosing HBO as the main component had its drawbacks like viscosities unexpectedly high. Except for viscosity, ageing promoted beneficial changes like lowering water content to a minimum of 0.93% and raising HHV to a maximum of 24.6 MJ kg(-1). (C) 2018 Elsevier Ltd. All rights reserved.