Calculating the closest approach parameter for ethyl lactate-based ATPS

• Type: Article in International Scientific Journal
• Date: 2022

Authors

Maria Eugénia Macedo (Author) FEUP; Pedro Velho (Author) FEUP; Elena Gómez (Author) Other

Journal

Title: Fluid Phase Equilibria

Vol. 556 No. 113389

ISSN: 0378-3812

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 0 Citations

ISI Web of Science

Scopus - 0 Citations

Scientific classification

CORDIS: Technological sciences

FOS: Engineering and technology

Associated Projects

LA LSRE-LCM - Financiamento Plurianual 2020-2023 para a Unidade LA LSRE-LCM Laboratório de Processos de Separação e Reacção - Laboratório de Catálise e Materiais

Other information

Authenticus ID: P-00W-04E

DOI: 10.1016/j.fluid.2022.113389

Abstract (EN): Aqueous Two-Phase Systems (ATPS) is a powerful separation technique for biotechnological compounds, such as pigments, proteins and flavonoids. Nowadays, ATPS generally include dissolved salts, which cause phase immiscibility and promote solute partition. Therefore, to accurately model the liquid-liquid equilibria (LLE) of these systems, specific terms for the long-range interactions in thermodynamic models are needed. A well-known hypothesis for this purpose is the Pitzer-Debye-Huckel (PDH) term, which requires the knowledge of the closest approach parameter (rho), i.e., an adjustable parameter. The aim of this work was calculating this parameter supposing total dissociation of the salts in ethyl lactate-based ATPS. In this new approach, rho became specific for each chemical species and its physical meaning (related to the distance between ions of different charges) was preserved. This method was applied in the LLE modelling of 7 ethyl lactate + organic or inorganic salts + water systems measured by the group, using the PDH term coupled with the UNIversal QUAsi-Chemical (UNIQUAC) model, whose junction is generally known as PDH+UNIQUAC, and compared with classical UNIQUAC and with previous works. The new approach accurately described the experimental liquid-liquid equilibria (LLE) data and presented smaller composition deviations than UNIQUAC.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8