화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.59, No.16, 7993-8003, 2020
Expanding SAFT-gamma Mie's Application to Dipolar Species: 2-Ketones, 3-Ketones, and Propanoate Esters
Statistical associating fluid theory (SAFT) equations of state (EoSs) are powerful thermodynamic modeling tools that show promise in application to a wide range of different properties and systems. SAFT-gamma Mie, the group-contribution variant of the state-of-the-art SAFT-VR Mie, can describe new systems using transferable functional-group parameters. There had been a void in the modeling of nonself-associating dipolar species prior to this work, in which groups were parametrized for 2-ketones, 3-ketones, and n-alkyl propanoates (viz. CH2CO, CH3CO, and COOpr., respectively). These components occur in a wide variety of industrial processes and modeling them with SAFT-gamma Mie presented the opportunity to evaluate the model's treatment of dipolar interactions without a fundamental dipolar term in the EoS. Our new groups provide reliable binary mixture phase-equilibrium, excess enthalpy, and speed of sound predictions for all of the considered components, despite the fact that 2-ketone pure-component predictions are slightly less accurate than what is expected from such a complex SAFT model. The latter observation suggests that very precise modeling of smaller, highly dipolar molecules is challenging with a first-order group-contribution model, even in the SAFT-VR Mie-based framework. Binary mixture VLE predictions of ketone + n-alkane and ketone +1-alkanol systems are in good agreement with experimental data, suggesting that the pseudo-association approach used to treat the dipolar interactions of ketones is adequate, and that its nonrigorous nature does not inherently produce an erroneous representation of the balance between different intermolecular interactions. Two successful high-pressure binary system VLE predictions were also generated, which may spur further research into using SAFT-gamma Mie and the new dipolar groups for modeling high-pressure systems.