A discrete modeling approach for excess Gibbs-energy models based on discrete Markov-chains

摘要

Thermodynamic models for fluid phase equilibria calculations, such as equations of state and activity coefficients, are being challenged by the need to describe complex and/or strongly oxygenated molecules. In this context, previous papers proposed 'discrete modeling' as a novel approach to incorporate a more detailed molecular picture into thermodynamics from scratch. The approach is characterized by the rigorous use of Shannon information as thermodynamic entropy. As a proof of concept, the thermal and caloric equations of state, heat capacity and Maxwell-Boltzmann distribution for ideal gas were derived on the basis of discrete states of individual molecules [1-2]. To further extend this approach to strongly interacting condensed-phase systems [3], in this paper a previous application of discrete Markov-chains to thermodynamic modeling [4] is modified and extended from a flat lattice towards a three-dimensional, Ising-type lattice model to be compared to Monte-Carlo data and established models based upon the well-known quasi-chemical approximation by Guggenheim.