Necessity of imposing total miscibility for certain binary pairs in LLE data correlations
| Autor: | Antonio Marcilla, Maria del Mar Olaya, Paloma Carbonell-Hermida |
|---|---|
| Přispěvatelé: | Universidad de Alicante. Departamento de Ingeniería Química, Universidad de Alicante. Instituto Universitario de Ingeniería de los Procesos Químicos, Procesado y Pirólisis de Polímeros |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Binodal
010405 organic chemistry Chemistry General Chemical Engineering General Physics and Astronomy Binary number 02 engineering and technology Type (model theory) Liquid-liquid equilibrium 01 natural sciences Miscibility 0104 chemical sciences Correlation Ingeniería Química 020401 chemical engineering NRTL Non-random two-liquid model Curve fitting LLE Statistical physics 0204 chemical engineering Physical and Theoretical Chemistry Ternary operation Data correlation Binodal curve |
| Popis: | Liquid-liquid equilibrium (LLE) data correlation of multicomponent mixtures is frequently carried out without using any procedure to ensure that the model parameters obtained for the totally miscible binary mixtures are consistent with such behavior (i.e. they do not lead to two liquid phases in equilibrium). In other words, the behavior of the model beyond the LLE region fitted (experimental tie-lines) is not usually considered in LLE correlations. It seems to be wrongly assumed that the mere absence of tie-lines data in totally miscible regions should guarantee that the parameters resulting from the LLE correlation lead to total miscibility in such homogeneous regions. We have checked that for the correlation of certain type 1 ternary systems (Treybal classification) a high probability exists of obtaining inconsistent model parameters, which lead to type 2 instead type 1 ternary behavior, unless specific restrictions for such parameters are imposed during the correlation. Commercial tools to carry out this type of data fitting, which are frequently included in process simulation packages such as Aspen Plus, do not include the possibility of applying such restrictions and consequently they could provide this type of misleading correlation results with serious consequences in equipment design. In the present paper, LLE data correlation for certain type 1 ternary systems has been carried out using Aspen Plus resulting in inconsistent type 2 results. These same systems have been satisfactorily correlated using our own correlation tools including restrictions to ensure the required miscibility behavior, and thus obtaining consistent parameters. A similar problem could occur in the correlation of the less frequent island (or zero) type ternary systems. Some examples are also presented for such type of systems. The authors would like to thank “Generalitat Valencia: Consellería de Educación, Investigación, Cultura y Deporte” for the PhD grant (ACIF/2019/040). |
| Databáze: | OpenAIRE |
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