A new inorganic atmospheric aerosol phase equilibrium model (UHAERO)

N. R. Amundson (1) , A. Caboussat (1) , J. W. He (1) , A. V. Martynenko (1) , V. B. Savarin (2) , J. H. Seinfeld (3) , K. Y. Yoo (4)

1 Department of Mathematics
2 ENSTA Paris - École Nationale Supérieure de Techniques Avancées
3 Departments of Chemical Engineering and Environmental Science and Engineering
4 Department of Chemical Engineering

A variety of thermodynamic models have been developed to predict inorganic gas-aerosol equilibrium. To achieve computational efficiency a number of the models rely on a priori specification of the phases present in certain relative humidity regimes. Presented here is a new computational model, named UHAERO, that is both efficient and rigorously computes phase behavior without any a priori specification. The computational implementation is based on minimization of the Gibbs free energy using a primal-dual method, coupled to a Newton iteration. The mathematical details of the solution are given elsewhere. The model computes deliquescence behavior without any a priori specification of the relative humidities of deliquescence. Also included in the model is a formulation based on classical theory of nucleation kinetics that predicts crystallization behavior. Detailed phase diagrams of the sulfate/nitrate/ammonium/water system are presented as a function of relative humidity at 298.15 K over the complete space of composition.

Domaines: Océan, Atmosphère

N. R. Amundson, A. Caboussat, J. W. He, A. V. Martynenko, V. B. Savarin, et al.. A new inorganic atmospheric aerosol phase equilibrium model (UHAERO). Atmospheric Chemistry and Physics, 2006, 6 (4), pp.992. ⟨hal-00328425⟩