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Razvoj industrije i separacijskih procesa fokusiran je na smanjenje zagađenja okoliša i potrošnje energije. Pojava azeotropa u mnogim sustavima zahtijeva posebne procese koji uključuju potrošnju velike količine energije i otapala što značajno utječe na okoliš. U svrhu unaprjeđenja separacije azeotropa, sve više se razmatra primjenjivost niskotemperaturnih eutektičkih otapala, zbog njihove jednostavne pripreme i ekološke prihvatljivosti U ovom radu istražena je mogućnost razdvajanja binarne azeotropne smjese n-heksana i etanola procesima ekstrakcijske destilacije i ekstrakcije, uz primjenu niskotemperaturnog eutektičkog otapala. Otapalo odabrano za eksperiment je kolin klorid – glicerol (molni omjer 1:2). The development of industries and separation processes focuses on the reduction of pollution and energy consumption. The emergence of azeotropes in many systems requires special processes involving large amounts of energy and severely environmentally impactful solvents. In order to improve the separation processes of azeotropes, the applicability of eutectic solvents is increasingly being considered due to their simple preparation and environmental friendliness. This paper investigated the possibility of separating a binary azeotropic mixture of n-hexane and ethanol by extractive distillation and extraction using a deep eutectic solvent. The solvent selected for the experiment was choline chloride - glycerol (molar ratio 1: 2).

Procesi razdvajanja azeotropnih smjesa od velikog su industrijskog interesa. Njihova provedba iziskuje velike količine energije, dok su otapala korištena u tu svrhu vrlo štetna za okoliš. S ciljem smanjenja potrošnje energije i poticanja održivog razvoja, otkrivena su eutektička otapala koja su ekološki prihvatljiva te jednostavna za pripremu. U ovom je radu istražena mogućnost razdvajanja binarne azeotropne smjese n-heksana i etanola procesima ekstrakcije i ekstrakcijske destilacije, primjenom niskotemperaturnog eutektičkog otapala. Korišteno otapalo u eksperimentu je kolin klorid – glicerol (molni omjer 1:2). Eksperimentalno je određena ravnoteža kapljevina – kapljevina kvazi-trokomponentnog sustava kolin klorid - glicerol – etanol – n-heksan pri atmosferskom tlaku i temperaturi od 25 °C. Također je istraženo kako rad pod sniženim tlakom utječe na sastav produkata dobivenih šaržnom destilacijom. Svim istraženim metodama dobiva se destilat koji sadrži veći udio n-heksana. 1H NMR spektroskopija može se koristiti za procjenu sastava produkata. Separation processes of azeotropic mixtures are of great industrial interest. Their implementation requires large amounts of energy, while the solvents used for this purpose are very harmful to the environment. In order to reduce the amount of energy used and encourage sustainable development, eutectic solvents have emerged because they are environmentally friendly and easy to prepare. In this paper, the possibility of separating a binary azeotropic mixture of n-hexane and ethanol was investigated by extraction and extractive distillation processes, using a deep eutectic solvent. The solvent used in the experiment was choline chloride - glycerol (molar ratio 1:2). The liquid - liquid equilibrium of the quasi-three-component system choline chloride - glycerol – ethanol – n-hexane was determined experimentally at atmospheric pressure and temperature of 25 °C. It was also investigated how reduced pressure affects the composition of products obtained by batch distillation. All the investigated methods yield a distillate containing a higher proportion of n-hexane. 1H NMR spectroscopy can be used to assess product composition.

Ovaj se rad bavi metodama destilacijskog razdvajanja azeotropnih smjesa. Kod azeotropnih smjesa, jednostavnom kolonskom destilacijom ne mogu se dobiti obje čiste komponente bez određenih modifikacija destilacijskog postupka, npr. promjenom tlaka ili dodatkom treće komponente. Rad opisuje teorijsku podlogu destilacije zeotropnih i azeotropnih smjesa, načine opisa neidealnosti kapljevitih otopina (Soave-Redlich-Kwong, Wilson i NRTL), te opis McCabe-Thieleove metode za proračun destilacijske kolone. Računski dio sastoji se od proračuna ekstraktivnog destilacijskog razdvajanja azeotropne smjese aceton – metanol na čiste komponente, uz dodatak izopropanola kao pomoćne komponente. Za modeliranje neidealnosti kapljevite faze korišteni su Wilsonov model koeficijenta aktivnosti te NRTL. Proračuni su provedeni u programskom sustavu CHEMCAD. This work is dealing with the methods of distillation separation of azeotrope mixtures. With azeotrope mixtures, two pure components cannot be obtained by a simple column distillation unless some modifications of the distillation procedure are introduced, e.g. by pressure swing or by adding third component. This work describes the theoretical background of distillation of zeotrope and azeotrope mixtures, ways of describing non-ideality of solutions (Soave-Redlich-Kwong, Wilson and NRTL), as well as the description of McCabe-Thiele method for calculations of distillation columns. The computation part is composed of the calculation of the extractive distillation separation of the azeotropic mixture of acetone – methanol into pure components, with the addition of isopropanol as an entrainer. Wilson and NRTL activity coefficient models were used for modeling non-ideality of the liquid phase. Calculations are performed within the CHEMCAD software.