A Fast Method To Calculate Residue Curve Maps

The perturbed chain-statistical associating fluid theory equation of state (PC-SAFT EoS) is one of the state-of-the-art thermodynamic models used in the phase equilibrium calculation of associating mixtures, in particular, in the pharmaceutical industry. Accordingly, parametrization of the PC-SAFT EoS for approved solvents reviewed for use in pharmaceutical process design by the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) was done in the present study. First, the PeC-SAFT EoS model parameters for 41 pure solvents were regressed (of 62 solvents). The available high-quality binary vapor–liquid equilibrium (VLE) data (944 out of 1891 binary systems) and also binary liquid–liquid equilibrium (LLE) data were used to tune the interaction parameters of the PC-SAFT model between the 62 solvents. The interaction parameters of 944 binary systems from 1891 (50%) solvent–solvent systems were regressed. To best fit the PC-SAFT model to the experimental data of 254 binary systems, in addition to the interaction parameters of the dispersion contribution (k ij ), the temperature-dependent effective cross-association volume of the association contribution (k A i B j ) was also fitted. The latter term plays a very important role in the fitting of the experimental VLE (systems that contain at least one associating component) and also LLE data (254 out of 944 binary systems). Using the obtained binary LLE parameters, the LLE phase behavior of 11 ternary LLE systems was successfully predicted by the PC-SAFT model. In addition, the heterogeneous residue curve map, azeotrope compositions, and temperatures of the water–ethanol–benzene system were successfully predicted by the PC-SAFT model. It was also shown that the performance of the PC-SAFT model was superior to those of UNIFAC, UNIFAC-LLE, UNIFAC-DMD, PSRK, VTPR, and UMR-PR models. Finally, the solubility of aripiprazole, cilostazol, imatinib, linagliptin, and naftopidil was regressed in pure solvents, and their solubility was successfully predicted in binary solvents. Hence, the PC-SAFT EoS in the current state together with the solvents confirmed by the ICH is a useful thermodynamic package to be used in the synthesis of active pharmaceutical ingredients, finished product formulations, and also purification operations.

Section: Results and Discussionmentioning

confidence: 99%

Parametrization of PC-SAFT EoS for Solvents Reviewed for Use in Pharmaceutical Process Design: VLE, LLE, VLLE, and SLE Study

Seyf

Asgari

2022

“…The proposed method reduces significantly the effort to provide improved designs if compared to the recursive use of simulation runs with commercial software. The approach can be extended to thermally coupled distillation systems for quaternary and multicomponent separations, whose preliminary designs must be also refined to meet specified product purities. , Also, with the inclusion of relative volatilities independent of temperature but dependent on the liquid-phase composition, as shown recently by Gutiérrez-Antonio et al for the construction of reside curve maps for nonideal mixtures, one could extend the basic equations and the methodology presented here to other complex systems, such as azeotropic and reactive distillation systems.…”

Section: Discussionmentioning

confidence: 98%

Design of Petlyuk Distillation Columns Aided with Collocation Techniques

Vaca¹,

Gutierrez

Monroy-Loperena³

2007

Self Cite

The use of shortcut methods for the design of complex distillation systems provides preliminary structures that need to be updated, typically by a recursive use of simulations. Although this procedure is generally effective, it can be time-consuming. In this work, collocation techniques are used as part of the design of Petlyuk distillation columns for the separation of ternary mixtures. Once a preliminary design is generated by a shortcut method, collocation techniques are applied to refine the location of the interconnecting and sidestream product stages, as well as the flowrate values of interlinking streams. The proposed method gives a proper distribution of stages for the Petlyuk system. The final designs are easily obtained with the proposed methodology, with a significant lower effort than that required when preliminary designs are corrected using recursive simulations.

“…Specifically, we propose a simplified approach for determining RRCMs by discarding the effect of temperature on the phase equilibrium constants, but preserving the composition effect. Although this assumption has been used for nonreactive mixtures, it has not been applied to the study of reactive mixtures. Our results indicate that the use of reaction-invariant composition variables and the application of simplified phase equilibrium constants (i.e., not dependent on temperature) avoid the iterative calculation of the reactive bubble temperature, resulting in an effective and faster strategy for estimating RRCMs.…”

Section: Introductionmentioning

confidence: 99%

A Short Method To Calculate Residue Curve Maps in Multireactive and Multicomponent Systems

Carrera-Rodríguez

Segovia‐Hernández

Bonilla-Petriciolet

2011

Reactive residue curve maps (RRCMs) are useful for the design of reactive distillation columns as a tool to establish feasible zones of reaction−separation. However, the calculation of an RRCM usually involves great computational effort due to the nonlinearity of the model equations and its iterative nature for the determination of reactive phase equilibrium. In this study, a simplified method for the generation of RRCMs is presented. This method is based on the application of reaction-invariant composition variables and assumes that the phase equilibrium constants (i.e., the relative volatilities) are independent of the temperature. Specifically, the phase equilibrium constants are calculated using a suitable estimation of the bubble temperature obtained from pure-component boiling temperatures and the reaction-invariant composition of liquid phase. These assumptions avoid iterative phase equilibrium calculations for obtaining a good approximation of RRCMs. Several reactive systems are used to identify the capabilities and limitations of the proposed method.