In this study, the thermodynamic behaviour of NO + SO2 mixtures has been investigated by means of molecular simulation, experiment and equation of state modelling. Quantum chemical calculation were performed to investigate possible chemical reactions between NO and SO2. Molecular simulations were based on Monte Carlo and Molecular Dynamics techniques using force fields available in the literature. Validation of simulated vapour liquid data for NO + SO2 binary mixtures was performed on the basis of proposed new experimental data, and new sets of parameters were optimized for the PPR78 EoS. We then moved our focus on the solubility of some gases (SOX, NOX, CO2, O-2, N-2) in water and brines studied by molecular simulations. We first compared performances of some combinations of salt and water intermolecular potentials in terms of density and osmotic pressure predictions. We then studied the evolution of Henry constant values for gases in brines considering various salt concentrations and temperatures. (C) 2018 Elsevier B.V. All rights reserved.