New Group-Interaction Parameters of the UNIFAC Model:  Aromatic Methoxyl Binaries

Abstract

Isothermal vapor−liquid equilibrium (VLE) data were measured for binary systems of 1-octanol + 2-methoxyphenol and 1-octanol + 1,2-dimethoxybenzene and a ternary system of 1,2-dimethoxybenzene + 2-methoxyphenol + 1-octanol at temperatures from 433 to 463 K. Maximum pressure azeotropes appeared in all three systems. Three correlative solution models were utilized in data reduction. Moreover, new group-interaction parameters of the UNIFAC model were determined from binary VLE data for several aromatic methoxyl (Ac-OCH3) binaries. The group-interaction parameters were tested with VLE data of ternary systems.

New Group Interaction Parameters of the UNIFAC (Dortmund) Model: Aromatic Dicarboxylic Acid Isomer and Methyl Benzoic Acid Isomer Binaries

“…However, the UNIFAC (Dortmund) model based on the group contribution method can solve the above problem theoretically, but the group division of the present UNIFAC (Dortmund) model has the following shortcomings. According to the group division in the present UNIFAC equation, the aliphatic COOH replaces the aromatic COOH, which will cause the problem in correlating the aromatic carboxylic acid systems. − Meanwhile, for the aromatic carboxylic acid isomer system with the same functional group composition, the γ i values calculated by the UNIFAC (Dortmund) model are consistent; therefore, these isomer molecules could not be distinguished clearly by the present UNIFAC group. Meanwhile, it does not reflect the molecular structure characteristics of these isomers.…”

Design, Simulation, and Pilot Verification of a Coupled Azeotropic and Extractive Distillation Process for the Production of Propylene Oxide with High Purity

“…In addition, both the model parameters and experimental data for PO + NC8 and PG + NC8 are not available in either the Aspen Plus database or the literature. Therefore, the pseudo-phase equilibrium for both systems is predicted by two different methods of UNIFAC , and COSMO-SAC , to ensure the reliability of the data. Although the two models are developed based on different principles, almost the same VLLE including the azeotropic temperature and composition for PG + NC8 is produced, as illustrated in Figure a.…”

A Fuzzy ARTMAP‐Based Quantitative Structure—Property Relationship (QSPR) for the Henry′s Law Constant of Organic Compounds.

“…[1][2][3]7 The simplest estimation is based on the theoretical expression H ) γ ∞ P s , where γ ∞ and P s are the chemical infinite dilution activity coefficient and saturation vapor pressure, respectively. Molecular activity coefficients at infinite dilution can be estimated with UNIFAC, 1,7,8 modified-UNIFAC, [7][8][9][10] and UNIQUAC 1 group contribution methods. The above methods require interaction parameters that are obtained from model fits to experimental phase-equilibrium data.…”

“…Unfortunately, group interaction parameters for UNI-FAC and reliable vapor pressure data are often lacking for chemicals of environmental interest, as well as for many heterocyclic aromatic compounds and compounds with functional groups containing sulfur and phosphorus. [7][8][9][10] Group contribution 11,12 and quantitative structure-property relations (QSPRs) [4][5][6][13][14][15][16] have been popular estimation methods of the Henry's Law constant for organic compounds. For example, Hine and Mookerjee 11 proposed bond contribution and group contribution schemes for logH, based on data sets of 263 and 212 compounds (-5 <logH <2), with a reported standard deviations of 0.42 and 0.12 logH units, respectively, for the above two sets.…”