Numerical simulation of bio-oil drop vaporization was performed in this study using a multicomponent approach based on its 10 dominant components, including water, levoglucosan, acetic acid, hydroxyacetaldehyde, hydroxypropanone. Bio-oil, also called pyrolysis oil, is derived from non-food biomass via the fast pyrolysis process and is a potential substitute for petroleum fuels. The bio-oil composition considered was obtained from experimental analysis of wood-derived bio-oil using GC/MS. Vaporization of a single bio-oil drop at 800 K was simulated, and results show continuous variations of the volume fractions of individual components in the drop. At the end of the vaporization process, only levoglucosan is left in the drop. The vaporization model for bio-oil was implemented into an engine simulation code to simulate a bio-oil spray in a constant-volume combustion chamber. Predicted vapor distributions of individual components indicate that at the early stage most of the vapor is acetic acid, hydroxyacetaldehyde, and hydroxypropanone. The present model was also extended to simulate the vaporization of mixtures of bio-oil and other practical fuels including diesel fuel, biodiesel, and ethanol. In particular, for the mixture of bio-oil and diesel fuel, a hybrid multicomponent modeling strategy was employed in which a continuous thermodynamics approach was used to model the diesel fuel present in the fuel mixture. Results show that bio-oil drops have longer lifetime than other fuels and the presence of bio-oil in the fuel mixtures extends the drop lifetime. The amount of bio-oil in the drop during vaporization evolves in a way determined by the relative volatilities between individual bio-oil components and the other fuel in the mixture. (C) 2011 Elsevier Ltd. All rights reserved.