Vapor−liquid equilibrium (VLE) data, essential for an accurate design of distillation columns, are not always readily available. This work has systematically assessed the feasibility of determining VLE data based on excess molar enthalpy (h E ) results. Twelve cubic Equation of State (cEoS) models combined with eight mixing rules and the Perturbed Chain Statistical Associating Fluid Theory (PC-SAFT) have been assessed. cEoS models are robust and applicable to a significant number of solvent families, while the PC-SAFT model is typically applied for strongly nonideal systems exhibiting molecular association behavior. VLE predictions based on the Peng−Robinson cEoS with the 2-parameter Stryjek− Vera−Margules-type mixing rule, one of the best cEoS−mixing rule combinations, was reasonably accurate, but less accurate than predictions based on the standard modified (mod.) UNIFAC (Do) model. This makes the developed h E −cEoS−VLE methodology relevant only for systems whose binary interaction parameters in UNIFAC (Do) and VLE data are not available. For the most nonideal self-associating systems evaluated, the PC-SAFT model parametrized with experimental h E data provided isobaric VLE results with similar or even higher accuracy than the mod. UNIFAC (Do) model. This indicates the potential of the h E −PC-SAFT− VLE model for accurately predicting VLE data for highly nonideal and associating systems. Therefore, this methodology can be used as a quick evaluation method for the separation of complex systems, including ionic liquids and deep eutectic solvents, for which the mod. UNIFAC (Do) model does not provide sufficiently accurate VLE predictions.
An extension of the equilibrium stage model to improve its applicability to reactive distillation is presented. The significant aeration of the liquid holdup on trays leads to the amount of clear liquid present being significantly less than the volume available. Tray hydraulic correlations are incorporated by leveraging the existing inside-out algorithm to rigorously calculate the liquid holdup on distillation trays, turning this parameter into an additional model output and eliminating the need to estimate this parameter beforehand. Application of this extended model shows that the aeration of the liquid holdup cannot be neglected for systems where the reaction kinetics limit the reactive productivity, and leads to column designs where additional reactive trays are needed to provide adequate reactive capacity. The workflow of this model provides a more robust path to obtaining reactive distillation column and tray designs that comply with liquid holdup requirements and tray hydraulic limitations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.