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Liquid-liquid equilibria of ternary (water + short-chain alcohol + organic solvent) systems
Desrosiers, Isabelle Grace. 2024. Liquid-liquid equilibria of ternary (water + short-chain alcohol + organic solvent) systems. Stellenbosch: Stellenbosch Univeristy [online]. Available: https://scholar.sun.ac.za/handle/10019.1/131638
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867613863191511040 |
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| access_status_str | Open Access |
| author | Desrosiers, Isabelle Grace |
| author2 | Schwarz, Cara E. |
| author_browse | Desrosiers, Isabelle Grace Schwarz, Cara E. |
| author_facet | Schwarz, Cara E. Desrosiers, Isabelle Grace |
| author_sort | Desrosiers, Isabelle Grace |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Desrosiers, Isabelle Grace. 2024. Liquid-liquid equilibria of ternary (water + short-chain alcohol + organic solvent) systems. Stellenbosch: Stellenbosch Univeristy [online]. Available: https://scholar.sun.ac.za/handle/10019.1/131638 |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/131638 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:42:53.367Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/131638 Liquid-liquid equilibria of ternary (water + short-chain alcohol + organic solvent) systems Desrosiers, Isabelle Grace Schwarz, Cara E. Lamprecht, Danielle L. Stellenbosch University. Faculty of Engineering. Dept. of Chemical Engineering. Liquid-liquid equilibrium Solutions (Chemistry) Thermodynamic equilibrium Separation (Technology) UCTD Desrosiers, Isabelle Grace. 2024. Liquid-liquid equilibria of ternary (water + short-chain alcohol + organic solvent) systems. Stellenbosch: Stellenbosch Univeristy [online]. Available: https://scholar.sun.ac.za/handle/10019.1/131638 Thesis (MEng)--Stellenbosch University, 2024. ENGLISH ABSTRACT: Anhydrous short-chain normal alcohols have numerous applications, from their use as fuel additives or replacements to their use in the chemical, pharmaceutical, and cosmetic industries. Short-chain alcohols are produced in water-rich streams. Separation of alcohol from water is therefore an important consideration in these processes. Azeotropes form in (water + n-alcohol) binary systems, which limits the maximum achievable purity of the alcohol product. This necessitates the use of advanced separation techniques, for which phase behaviour data is essential. These techniques include heterogeneous azeotropic distillation (HAD), which requires a decanter. Although individual solvents have been studied for alcohol HAD processes, comparison of solvents across multiple functional groups in a single study is not typically done. In addition, the use of a thermodynamic model to describe phase equilibria is common practice, but thermodynamically inconsistent solutions can be obtained for modelling liquid-liquid equilibria (LLE). The aim of this work is to improve the understanding of the effect of temperature and the organic solvent structure on the liquid-liquid behaviour in ternary (water + ethanol/n-propanol/n-butanol + isooctane/cyclohexane/diisopropyl ether/isoamyl alcohol) systems between 298.15 K and 318.15 K. Nineteen datasets were measured in this work. The experimental data show that the organic solvent undoubtedly affects the phase behaviour. The behaviour is affected by the alcohol’s preference in phase. Particularly, the alcohol’s preference for the organic phase increases with increasing solubility in the (water + organic solvent) binary pair and the increasing nonideality in the (water + alcohol) binary pair. Moreover, there is increasing ideality in the (alcohol + organic solvent) binary pair. These observations are due to the change in functional group and the length of the alcohol’s carbon chain. These interactions result in the observed behaviour, where the alcohol recovery to the organic phase is higher but the selectivity towards the alcohol is lower for oxygenated solvent systems. The effect of temperature decreases with increasing solubility of the organic solvent in water and the alcohol as well as with increasing nonideality in the (water + alcohol) binary pair. These trends are because the alcohol, which dominates the interactions between unlike molecules in the mixture, partakes in more dispersion forces as its carbon chain length increases. Since dispersion forces are relatively temperature independent, there is less temperature dependence in the overall system. The (water + ethanol + hydrocarbon solvent) and (water + n-propanol + isooctane) systems show the greatest temperature dependence of the twelve systems considered in this work. The approach implemented for parametrisation of the non-random two-liquid (NRTL) model in Aspen Plus® was successful for ten of the twelve systems considered in this work. The (water + n-propanol + hydrocarbon solvent) systems, which were unsuccessful, are documented to be difficult to model due to the complex phase behaviour in these systems. The results of this work show that obtaining thermodynamically consistent solutions using Aspen Plus® for ternary liquid-liquid systems is possible. Moreover, the results provide good descriptions of the experimental data. AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar. Masters 2025-02-03T07:27:11Z 2025-02-03T07:27:11Z 2024-12 Thesis https://scholar.sun.ac.za/handle/10019.1/131638 en Stellenbosch University xiii, 373 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Liquid-liquid equilibrium Solutions (Chemistry) Thermodynamic equilibrium Separation (Technology) UCTD Desrosiers, Isabelle Grace Liquid-liquid equilibria of ternary (water + short-chain alcohol + organic solvent) systems |
| title | Liquid-liquid equilibria of ternary (water + short-chain alcohol + organic solvent) systems |
| title_full | Liquid-liquid equilibria of ternary (water + short-chain alcohol + organic solvent) systems |
| title_fullStr | Liquid-liquid equilibria of ternary (water + short-chain alcohol + organic solvent) systems |
| title_full_unstemmed | Liquid-liquid equilibria of ternary (water + short-chain alcohol + organic solvent) systems |
| title_short | Liquid-liquid equilibria of ternary (water + short-chain alcohol + organic solvent) systems |
| title_sort | liquid liquid equilibria of ternary water short chain alcohol organic solvent systems |
| topic | Liquid-liquid equilibrium Solutions (Chemistry) Thermodynamic equilibrium Separation (Technology) UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/131638 |
| work_keys_str_mv | AT desrosiersisabellegrace liquidliquidequilibriaofternarywatershortchainalcoholorganicsolventsystems |