Heats of mixing of the ternary systems 1-propanol-n-alkane-cyclohexane

1982 ◽  
Vol 47 (4) ◽  
pp. 1045-1059 ◽  
Author(s):  
František Veselý ◽  
Vladimír Dohnal ◽  
Miloslav Prchal
Keyword(s):  
Ternary Systems ◽  
Group Contribution ◽  
Polar Component ◽  
Excess Enthalpies ◽  
Group Contribution Method ◽  
Heats Of Mixing ◽  
Scatchard Equation ◽  
System 1 ◽  
Associated Solution ◽  
Good Agreement

Heats of mixing HE were measured at the temperature of 298 15 K in the ternary system 1-propanol-n-hexane-cyclohexane, 1-propanol-n-heptane-cyclohexane and 1-propanol-n-octane cyclohexane along three pseudobinary chorids and in the binary system 1-propanol-n-hexane. The measured values of the ternary excess enthalpies were correlated by the Scatchard equation for one polar component and by the SSF equation in pseudobinary mixtures. A very good agreement with the experiments was attained on computing the enthalpies of mixing by the group-contribution method. Qualitatively the same results were found on applying the modified Renon-Prausnitz model of continuously associated solution. The combination of the Renon-Prausnitz model with the group-contribution method did not yield a more conspicuous improvement.

scholarly journals NEAT-NMR Spectroscopy for the Estimation of Activity Coefficients of Target Components in Poorly Specified Mixtures

2021 ◽  
Author(s):  
Fabian Jirasek ◽  
Jakob Burger ◽  
Hans Hasse
Keyword(s):  
Nmr Spectroscopy ◽  
Activity Coefficients ◽  
Group Contribution ◽  
Target Component ◽  
Full Detail ◽  
Group Contribution Method ◽  
Lack Of Information ◽  
Basic Ideas ◽  
Chemical Groups ◽  
Good Agreement

Mixtures of which the composition is not fully known are important in many fields of engineering and science, for example, in biotechnology. Owing to the lack of information on the composition, such mixtures cannot be described with common thermodynamic models. In the present work, a method is described with which this obstacle can be overcome for an important class of problems. The method enables the estimation of the activity coefficients of target components in poorly specified mixtures and is based on a combination of NMR spectroscopy with a thermodynamic group contribution method. It is therefore called the NEAT method (NMR spectroscopy for the Estimation of Activity coefficients of Target components in poorly specified mixtures). In NEAT, NMR spectroscopy is used to obtain information on the concentrations of chemical groups in the mixture. The elucidation of the speciation is not required, only the target component has to be known. Modified UNIFAC (Dortmund) is applied in the present work as group contribution method, but NEAT can be extended to any other group contribution method. NEAT was introduced recently by our group in a short communication, but only the basic ideas were presented. In the present work, NEAT is described in full detail. Different options of using NEAT are discussed, and examples for the application of the method are given. They include a variety of aqueous and nonaqueous mixtures. The results show very good agreement of the activity coefficients that are predicted by NEAT with the corresponding results for the fully specified mixtures.

Heats of mixing of butanone and chloroform with alkanes: Ternary systems

1978 ◽  
Vol 43 (3) ◽  
pp. 837-847 ◽  
Author(s):  
Julius Pouchlý ◽  
Antonín Živný ◽  
Ján Biroš
Keyword(s):  
Ternary Systems ◽  
Heats Of Mixing

Interpretation of heats of mixing of 1-butanol, 2-butanol and 2-methyl-2-propanol with cyclohexane in terms of some models of continuously associated solution

1984 ◽  
Vol 49 (6) ◽  
pp. 1334-1341 ◽  
Author(s):  
František Veselý ◽  
Vladimír Dohnal ◽  
Miriam Valentová ◽  
Jiří Pick
Keyword(s):  
Temperature Dependence ◽  
Interaction Parameters ◽  
Heats Of Mixing ◽  
Linear Association ◽  
Two Systems ◽  
Associated Solution

Three models of continuously associated solution complemented by an assumption of polynomial temperature dependence of corresponding interaction parameters were used for simultaneous description of the concentration and temperature dependence of heats of mixing of 1-butanol, 2-butanol and 2-methyl-2-propanol with cyclohexane. Very good results were reached for the first two systems where the Liebermann and Wilhelm model has proved to be the most suitable. With respect to the probable existence of cyclic associates in solutions of 2-methyl-2-propanol, none of the used models which assume only linear association satisfied to the extent required.

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