Phase Behavior of Biomass Components in Supercritical Water

Abstract

The importance of thermodynamic and phase behavior is fundamental to supercritical water (SCW) technologies of biomass treatment. Considering the extremely large number of biomass components, it is obvious that there is need for developing theoretically sound methods of the prompt estimation of their phase behavior in aquatic media at supercritical conditions. A local mapping concept is introduced to describe thermodynamically consistently the saturation curve of water and biomass components. The global phase diagram studies of binary mixtures provide some basic ideas of how the required methods can be developed to visualize the phase behavior of biomass decomposition products in supercritical aqueous media. The mapping of the global equilibrium surface in the parameter space of the equation of state (EoS) model provides the most comprehensive system of criteria for predicting binary mixture phase behavior. Analytical expressions for selection the azeotropic states in binary mixtures are given. Results of calculations of phase equilibria and critical curves for main biomass components in supercritical water are described.