Modeliranje ravnoteže kapljevina-kapljevina u kvazi-sedmerokomponentnim sustavima s niskotemperaturnim eutektičkim otapalima kao ekstrakcijskim sredstvima

Liquid-liquid equilibria were experimentally investigated in systems in which the first component was aliphatic (n-hexane, n-heptane or i-octane) or aromatic hydrocarbon (toluene), the second component was pyridine or thiophene, and the third quasi-component was DES consisting of choline chloride and glycerol or choline chloride and ethylene glycol, at 25 °C and atmospheric pressure. The equilibria were successfully described by the NRTL and UNIQUAC models. The same models were successfully applied to describe the liquid-liquid equilibria in quasi-seven-component systems that comprised all the mentioned low molecular weight components and one DES. The restrictions of the models were discussed; it seems that the preference can be given to the UNIQUAC model. This work is licensed under a Creative Commons Attribution 4.0 International License.Eksperimentalno su istražene ravnoteže kapljevina-kapljevina u sustavima u kojem je prva komponenta alifatski (n-heksan, n-heptan odnosno i-oktan) ili aromatski ugljikovodik (toluen), druga komponenta je piridin ili tiofen, a treća kvazi-komponenta je DES koji se sastoji od kolin klorida i glicerola, odnosno kolin klorida i etilen-glikola, pri 25 °C i atmosferskom tlaku. Ravnoteže su uspješno opisane modelima NRTL i UNIQUAC. Isti su modeli uspješno primijenjeni i za opis ravnoteža kapljevina-kapljevina i u kvazi-sedmerokomponentnim sustavima koji uključuju sve navedene niskomolekulske komponente i jedan DES. Raspravljena su ograničenja modela; čini se da se prednost može dati modelu UNIQUAC. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

Ružička days : International conference 16th Ružička Days “Today Science – Tomorrow Industry” : Proceedings

Proceedings contains articles presented at Conference divided into sections: open lecture (1), chemical analysis and synthesis (3), chemical and biochemical engineering (8), food technology and biotechnology (8), medical chemistry and pharmacy (3), environmental protection (11) and meeting of young chemists (2)

Deep eutectic solvents for the extraction of sulfur and nitrogen compounds from hydrocarbon mixtures

U ovoj disertaciji pripremljeno je šest niskotemperaturnih eutektičnih otapala različitih molarnih omjera: ChCl-Gly 1:1,5, ChCl-Gly 1:2, ChCl-Gly 1:3, ChCl-EG 1:2, ChCl-EG 1:3 i ChCl-EG 1:3,5, te su karakterizirana njihova fizikalno-kemijska svojstva bitna za proces ekstrakcije. Određene su ravnoteže kapljevina-kapljevina u trokomponentnim sustavima ugljikovodik – tiofen ili piridin – eutektično otapalo. Istraženi su sljedeći ugljikovodici: n-heksan, n-heptan, i-oktan i toluen. Ravnoteže su uspješno opisane modelima koeficijenta aktivnosti NRTL (engl. non-random two liquid) i UNIQUAC (engl. universal quasi-chemical equation), ali se prednost može dati UNIQUACu. Topljivost piridina (maks. 78 %) u eutektičnom otapalu znatno je veća od topljivosti tiofena, koja ne prelazi 10 %. Međusobno miješanje ugljikovodika i eutektičnih otapala nije uočeno, pa se zaključuje da su ispitana eutektična otapala selektivna za tiofen i piridin, povećanoga afiniteta za dušikove spojeve. U pokušaju razvoja alternativnih metoda po kriterijima ‘zelenih’ tehnologija u proizvodnji benzina, ispitana je mogućnost primjene pripremljenih eutektičnih otapala za desulfurizaciju, denitrifikaciju i dearomatizaciju modelnog i realnog FCC-benzina (engl. fluid catalytic cracking) ekstrakcijom kapljevina-kapljevina pri atmosferskim uvjetima. Modelni benzin je otopina koja sadrži 26 % n-heksana, 26 % n-heptana, 26 % i-oktana, 10 % toluena, 6 % piridina i 6% tiofena, a svojim sastavom imitira FCC-benzin. Iz preliminarnih eksperimenata osmišljeni su radni uvjeti ekstrakcijskih eksperimenata. Za potrebe analize sastava rafinatne faze nakon ekstrakcije, razvijena je metoda plinske kromatografije. Od istraženih masenih omjera otapalo : modelni benzin najboljim se pokazao omjer 1:1 u svim sustavima. S manjim masenim omjerom u višestupanjskoj se ekstrakciji postiže jednaka djelotvornost ekstrakcije kao s omjerom 1:1 u jednostupanjskoj. Bez pročišćavanja otapala između ekstrakcijskih stupnjeva smanjuje se njegov ekstrakcijski kapacitet. Regeneracija otapala između stupnjeva uspješno se provodi jednostavnim vakuumskim isparavanjem otopljenih komponenti, bez gubitka ekstrakcijske djelotvornosti. Sva ispitana eutektična otapala pokazala su veći potencijal za denitrifikaciju nego desulfurizaciju i dearomatizaciju. Iz grupe otapala na osnovi glicerola najbolji je ChCl-Gly 1:3, a iz grupe na osnovi etilen-glikola ChCl-EG 1:3,5. Rezultati pokazuju da se djelotvornost denitrifikacije povećava s udjelom donora vodikove veze u eutektičnom otapalu. Isti je trend ponašanja opažen i kod eksperimenata s uzorcima realnog FCC-benzina.In this dissertation six deep eutectic solvents in various molar ratios: ChCl-Gly 1:1,5, ChCl-Gly 1:2, ChCl-Gly 1:3, ChCl-EG 1:2, ChCl-EG 1:3 i ChCl-EG 1:3 were prepared, and characterization of their physicochemical properties essential for the extraction process were made. The liquid-liquid equilibria for the ternary systems hydrocarbon – pyridine or thiophene – eutectic solvent were determined. The hydrocarbon was varied between n-hexane, n-heptane, i-octane or toluene. Equilibria were successfully described by NRTL and UNIQUAC activity coefficient models, but the preference can be given to the UNIQUAC model. The solubility of pyridine (max. 78 %) in the deep eutectic solvent was significantly higher than the solubility of thiophene, which did not exceed 10%. Mixing of hydrocarbons and deep eutectic solvents was not observed, so it is concluded that the tested eutectic solvents are selective for thiophene and pyridine, with affinity for denitrification. In an attempt to develop alternative methods that meet the criteria of 'green' technology in gasoline production, the possibility of using prepared eutectic solvents for desulfurization, denitrification and dearomatization of model and real FCC-gasoline by liquid-liquid extraction under atmospheric conditions was investigated. Model gasoline is a solution containing 26 % of n-hexane, 26 % of n-heptane, 26 % of i-octane, 10 % of toluene, 6 % of pyridine and 6 % of thiophene and its composition mimics FCC-gasoline. From the preliminary experiments, the working conditions of the extraction experiments were designed. For the purpose of analysis of the raffinate phase composition after extraction, a gas chromatography method was developed. The best mass ratio of solvent : model gasoline was determined; it amounted 1:1 in all systems. With a lower mass ratio, in multistage extraction, the same extraction efficiency was achieved as with the optimum one. The extraction capacity of the solvent was reduced without purification of the solvent between the extraction steps. Solvent regeneration was successfully done by simple vacuum evaporation of the dissolved components between stages, without a loss in extraction efficiency. All tested eutectic solvents showed higher affinity for denitrification than desulfurization and dearomatization. ChCl-Gly 1:3 was selected from the group of glycerol-based solvents, and ChCl-EG 1:3.5 was selected from ethylene glycolbased solvents. The results showed that the denitrification efficiency increased with the content of hydrogen bond donors in deep eutectic solvent. The same trend of behavior was present in real gasoline samples

Deep eutectic solvents for the extraction of sulfur and nitrogen compounds from hydrocarbon mixtures

U ovoj disertaciji pripremljeno je šest niskotemperaturnih eutektičnih otapala različitih molarnih omjera: ChCl-Gly 1:1,5, ChCl-Gly 1:2, ChCl-Gly 1:3, ChCl-EG 1:2, ChCl-EG 1:3 i ChCl-EG 1:3,5, te su karakterizirana njihova fizikalno-kemijska svojstva bitna za proces ekstrakcije. Određene su ravnoteže kapljevina-kapljevina u trokomponentnim sustavima ugljikovodik – tiofen ili piridin – eutektično otapalo. Istraženi su sljedeći ugljikovodici: n-heksan, n-heptan, i-oktan i toluen. Ravnoteže su uspješno opisane modelima koeficijenta aktivnosti NRTL (engl. non-random two liquid) i UNIQUAC (engl. universal quasi-chemical equation), ali se prednost može dati UNIQUACu. Topljivost piridina (maks. 78 %) u eutektičnom otapalu znatno je veća od topljivosti tiofena, koja ne prelazi 10 %. Međusobno miješanje ugljikovodika i eutektičnih otapala nije uočeno, pa se zaključuje da su ispitana eutektična otapala selektivna za tiofen i piridin, povećanoga afiniteta za dušikove spojeve. U pokušaju razvoja alternativnih metoda po kriterijima ‘zelenih’ tehnologija u proizvodnji benzina, ispitana je mogućnost primjene pripremljenih eutektičnih otapala za desulfurizaciju, denitrifikaciju i dearomatizaciju modelnog i realnog FCC-benzina (engl. fluid catalytic cracking) ekstrakcijom kapljevina-kapljevina pri atmosferskim uvjetima. Modelni benzin je otopina koja sadrži 26 % n-heksana, 26 % n-heptana, 26 % i-oktana, 10 % toluena, 6 % piridina i 6% tiofena, a svojim sastavom imitira FCC-benzin. Iz preliminarnih eksperimenata osmišljeni su radni uvjeti ekstrakcijskih eksperimenata. Za potrebe analize sastava rafinatne faze nakon ekstrakcije, razvijena je metoda plinske kromatografije. Od istraženih masenih omjera otapalo : modelni benzin najboljim se pokazao omjer 1:1 u svim sustavima. S manjim masenim omjerom u višestupanjskoj se ekstrakciji postiže jednaka djelotvornost ekstrakcije kao s omjerom 1:1 u jednostupanjskoj. Bez pročišćavanja otapala između ekstrakcijskih stupnjeva smanjuje se njegov ekstrakcijski kapacitet. Regeneracija otapala između stupnjeva uspješno se provodi jednostavnim vakuumskim isparavanjem otopljenih komponenti, bez gubitka ekstrakcijske djelotvornosti. Sva ispitana eutektična otapala pokazala su veći potencijal za denitrifikaciju nego desulfurizaciju i dearomatizaciju. Iz grupe otapala na osnovi glicerola najbolji je ChCl-Gly 1:3, a iz grupe na osnovi etilen-glikola ChCl-EG 1:3,5. Rezultati pokazuju da se djelotvornost denitrifikacije povećava s udjelom donora vodikove veze u eutektičnom otapalu. Isti je trend ponašanja opažen i kod eksperimenata s uzorcima realnog FCC-benzina.In this dissertation six deep eutectic solvents in various molar ratios: ChCl-Gly 1:1,5, ChCl-Gly 1:2, ChCl-Gly 1:3, ChCl-EG 1:2, ChCl-EG 1:3 i ChCl-EG 1:3 were prepared, and characterization of their physicochemical properties essential for the extraction process were made. The liquid-liquid equilibria for the ternary systems hydrocarbon – pyridine or thiophene – eutectic solvent were determined. The hydrocarbon was varied between n-hexane, n-heptane, i-octane or toluene. Equilibria were successfully described by NRTL and UNIQUAC activity coefficient models, but the preference can be given to the UNIQUAC model. The solubility of pyridine (max. 78 %) in the deep eutectic solvent was significantly higher than the solubility of thiophene, which did not exceed 10%. Mixing of hydrocarbons and deep eutectic solvents was not observed, so it is concluded that the tested eutectic solvents are selective for thiophene and pyridine, with affinity for denitrification. In an attempt to develop alternative methods that meet the criteria of 'green' technology in gasoline production, the possibility of using prepared eutectic solvents for desulfurization, denitrification and dearomatization of model and real FCC-gasoline by liquid-liquid extraction under atmospheric conditions was investigated. Model gasoline is a solution containing 26 % of n-hexane, 26 % of n-heptane, 26 % of i-octane, 10 % of toluene, 6 % of pyridine and 6 % of thiophene and its composition mimics FCC-gasoline. From the preliminary experiments, the working conditions of the extraction experiments were designed. For the purpose of analysis of the raffinate phase composition after extraction, a gas chromatography method was developed. The best mass ratio of solvent : model gasoline was determined; it amounted 1:1 in all systems. With a lower mass ratio, in multistage extraction, the same extraction efficiency was achieved as with the optimum one. The extraction capacity of the solvent was reduced without purification of the solvent between the extraction steps. Solvent regeneration was successfully done by simple vacuum evaporation of the dissolved components between stages, without a loss in extraction efficiency. All tested eutectic solvents showed higher affinity for denitrification than desulfurization and dearomatization. ChCl-Gly 1:3 was selected from the group of glycerol-based solvents, and ChCl-EG 1:3.5 was selected from ethylene glycolbased solvents. The results showed that the denitrification efficiency increased with the content of hydrogen bond donors in deep eutectic solvent. The same trend of behavior was present in real gasoline samples

Deep eutectic solvents for the extraction of sulfur and nitrogen compounds from hydrocarbon mixtures

U ovoj disertaciji pripremljeno je šest niskotemperaturnih eutektičnih otapala različitih molarnih omjera: ChCl-Gly 1:1,5, ChCl-Gly 1:2, ChCl-Gly 1:3, ChCl-EG 1:2, ChCl-EG 1:3 i ChCl-EG 1:3,5, te su karakterizirana njihova fizikalno-kemijska svojstva bitna za proces ekstrakcije. Određene su ravnoteže kapljevina-kapljevina u trokomponentnim sustavima ugljikovodik – tiofen ili piridin – eutektično otapalo. Istraženi su sljedeći ugljikovodici: n-heksan, n-heptan, i-oktan i toluen. Ravnoteže su uspješno opisane modelima koeficijenta aktivnosti NRTL (engl. non-random two liquid) i UNIQUAC (engl. universal quasi-chemical equation), ali se prednost može dati UNIQUACu. Topljivost piridina (maks. 78 %) u eutektičnom otapalu znatno je veća od topljivosti tiofena, koja ne prelazi 10 %. Međusobno miješanje ugljikovodika i eutektičnih otapala nije uočeno, pa se zaključuje da su ispitana eutektična otapala selektivna za tiofen i piridin, povećanoga afiniteta za dušikove spojeve. U pokušaju razvoja alternativnih metoda po kriterijima ‘zelenih’ tehnologija u proizvodnji benzina, ispitana je mogućnost primjene pripremljenih eutektičnih otapala za desulfurizaciju, denitrifikaciju i dearomatizaciju modelnog i realnog FCC-benzina (engl. fluid catalytic cracking) ekstrakcijom kapljevina-kapljevina pri atmosferskim uvjetima. Modelni benzin je otopina koja sadrži 26 % n-heksana, 26 % n-heptana, 26 % i-oktana, 10 % toluena, 6 % piridina i 6% tiofena, a svojim sastavom imitira FCC-benzin. Iz preliminarnih eksperimenata osmišljeni su radni uvjeti ekstrakcijskih eksperimenata. Za potrebe analize sastava rafinatne faze nakon ekstrakcije, razvijena je metoda plinske kromatografije. Od istraženih masenih omjera otapalo : modelni benzin najboljim se pokazao omjer 1:1 u svim sustavima. S manjim masenim omjerom u višestupanjskoj se ekstrakciji postiže jednaka djelotvornost ekstrakcije kao s omjerom 1:1 u jednostupanjskoj. Bez pročišćavanja otapala između ekstrakcijskih stupnjeva smanjuje se njegov ekstrakcijski kapacitet. Regeneracija otapala između stupnjeva uspješno se provodi jednostavnim vakuumskim isparavanjem otopljenih komponenti, bez gubitka ekstrakcijske djelotvornosti. Sva ispitana eutektična otapala pokazala su veći potencijal za denitrifikaciju nego desulfurizaciju i dearomatizaciju. Iz grupe otapala na osnovi glicerola najbolji je ChCl-Gly 1:3, a iz grupe na osnovi etilen-glikola ChCl-EG 1:3,5. Rezultati pokazuju da se djelotvornost denitrifikacije povećava s udjelom donora vodikove veze u eutektičnom otapalu. Isti je trend ponašanja opažen i kod eksperimenata s uzorcima realnog FCC-benzina.In this dissertation six deep eutectic solvents in various molar ratios: ChCl-Gly 1:1,5, ChCl-Gly 1:2, ChCl-Gly 1:3, ChCl-EG 1:2, ChCl-EG 1:3 i ChCl-EG 1:3 were prepared, and characterization of their physicochemical properties essential for the extraction process were made. The liquid-liquid equilibria for the ternary systems hydrocarbon – pyridine or thiophene – eutectic solvent were determined. The hydrocarbon was varied between n-hexane, n-heptane, i-octane or toluene. Equilibria were successfully described by NRTL and UNIQUAC activity coefficient models, but the preference can be given to the UNIQUAC model. The solubility of pyridine (max. 78 %) in the deep eutectic solvent was significantly higher than the solubility of thiophene, which did not exceed 10%. Mixing of hydrocarbons and deep eutectic solvents was not observed, so it is concluded that the tested eutectic solvents are selective for thiophene and pyridine, with affinity for denitrification. In an attempt to develop alternative methods that meet the criteria of 'green' technology in gasoline production, the possibility of using prepared eutectic solvents for desulfurization, denitrification and dearomatization of model and real FCC-gasoline by liquid-liquid extraction under atmospheric conditions was investigated. Model gasoline is a solution containing 26 % of n-hexane, 26 % of n-heptane, 26 % of i-octane, 10 % of toluene, 6 % of pyridine and 6 % of thiophene and its composition mimics FCC-gasoline. From the preliminary experiments, the working conditions of the extraction experiments were designed. For the purpose of analysis of the raffinate phase composition after extraction, a gas chromatography method was developed. The best mass ratio of solvent : model gasoline was determined; it amounted 1:1 in all systems. With a lower mass ratio, in multistage extraction, the same extraction efficiency was achieved as with the optimum one. The extraction capacity of the solvent was reduced without purification of the solvent between the extraction steps. Solvent regeneration was successfully done by simple vacuum evaporation of the dissolved components between stages, without a loss in extraction efficiency. All tested eutectic solvents showed higher affinity for denitrification than desulfurization and dearomatization. ChCl-Gly 1:3 was selected from the group of glycerol-based solvents, and ChCl-EG 1:3.5 was selected from ethylene glycolbased solvents. The results showed that the denitrification efficiency increased with the content of hydrogen bond donors in deep eutectic solvent. The same trend of behavior was present in real gasoline samples

Deep Eutectic Solvents for Biodiesel Purification in a Microextractor: Solvent Preparation, Selection and Process Optimization

The most important and commonly used process for biodiesel synthesis is transesterification. The main by-product of biodiesel synthesis by transesterification is glycerol, which must be removed from the final product. Recently, deep eutectic solvent (DES) assisted extraction has been shown to be an effective and sustainable method for biodiesel purification. In this study, biodiesel was produced by lipase-catalysed transesterification from sunflower oil and methanol. A total of 12 different eutectic solvents were prepared and their physical properties were determined. Mathematical models were used to define which physical and chemical properties of DES and to what extent affect the efficiency of extraction of glycerol from the biodiesel. After initial screening, cholinium-based DES with ethylene glycol as hydrogen bond donor was selected and used for optimization of extraction process conditions performed in a microsystem. To determine the optimal process conditions (temperature, biodiesel:DES volume ratio, residence time), the experimental three-level-three-factor Box-Behnken experimental design was used. In the end, a combination of a mathematical model and experimental results was used to estimate how many micro-extractors are necessary for the complete removal of glycerol

Ružička days : International conference 18th Ružička Days “Today Science – Tomorrow Industry” : Proceedings

Proceedings contains articles presented at Conference divided into sections: chemical analysis and synthesis, chemical and biochemical engineering, food technology and biotechnology, medical chemistry and pharmacy, environmental protection and meeting of young chemists