Uticaj kosolvenata na etanolizu suncokretovog ulja katalizovanoj kalcijum-oksidom: doktorske disertacije

In this dissertation, the influence of different organic solvents (triethanolamine, diethanolamine, ethylene glycol, methyl ethyl ketone, n-hexane, triethylamine, ethylene glycol dimethyl ether, glycerol, tetrahydrofuran and dioxane) as cosolventethanolysis of sunflower oil catalyzed by calcinated CaO. Ethanolysis was performed as a heterogeneous base-catalyzed process in which calcinated CaO in a stirred batch reactor was used as a catalyst. The reaction conditions were: temperature 70 °C, ethanol:oil molar ratio 12:1, catalyst concentration 1.374 mol·dm-3 and cosolvent amount 20% by weight of oil. Without cosolvent, the reaction is relatively slow, because the EEMK content of 89.7 ± 1.73% was obtained only after 4 h of reaction. Of the cosolvents used, only diethanolamine, triethanolamine and ethylene glycol had a positive effect on the rate of ethanolysis reaction, with the use of triethanolamine and ethylene glycol achieved the highest EEMK content of 93.1±2.1 and 94.1± 1.5%, respectively, after 0,5 h reaction. Based on the experimental results, triethanolamine and the cosolvent that had the greatest positive effect on the rate of the transesterification reaction of the safety profile were selected, triethanolamine was selected as the best cosolvent of the reaction ethanolysis reaction catalyzed by CaO. The reaction with triethanolamine was optimized with respect to temperature (61,6-78,4 °C), ethanol:oil molar ratio (7:1-17:1) and cosolvent amount (3-36%, by weight of oil) using a central composite rotatable experimental design (RCCD) in combination with a response surface methodology (RSM). The optimal reaction conditions are: molar ratio ethanol:oil 9:1, temperature 75 °C and cosolvent amount 30% ( to the mass of oil), where the predicted value of EEMK content after only 20 min of reaction was 98,8%, while the experimentally obtained value was 97,9 ± 1,3%. High EEMK contents were also obtained during the application of expired sunflower oil, hemp oil and waste lard. X-ray diffraction analysis (XRD) was used to understand the structural changes of CaO catalysts. The CaO catalyst could be used without any additional treatment in two consecutive cycles. Due to the leaching of calcium into the product, an additional purification process must be included in the entire production process

Choline chloride-based deep eutectic solvents in CaO-catalyzed ethanolysis of expired sunflower oil

Choline chloride (ChCl)-based deep eutectic solvents (DESs) with different amides or polyols as hydrogen bond donors were tested as cosolvents in the ethanolysis of expired sunflower oil catalyzed by either calcined or non-calcined CaO. These cosolvents promoted the ethanolysis by a successful activation of non-calcined CaO, which was ascribed to the CaCO3 and Ca(OH)2 dissolution from the surface of the solid catalyst particles. With both calcined and non-calcined CaO, the polyol-based solvents gave higher fatty acid ethyl esters (FAEE) content than the amide-based solvents. Among the amide-based DESs, choline chloride:urea (ChCl:U) was the most efficient activator of non-calcined CaO. Choline chloride:ethylene glycol (ChCl:EG) and choline chloride:propylene glycol (ChCl:PG) were more efficient than choline chloride:glycerol (ChCl:G) even with non-calcined CaO. However, ChCl:G might be more suitable than the others since the use of glycerol, a by-product of the ethanolysis, could reduce the overall biodiesel production costs. FTIR and XRD analyses of the used and separated CaO were performed in order to get more insight into the catalytically active phase(s). Also, the mechanisms of the CaO activation in the presence of the DESs were considered. The phase separation of the reaction mixture was faster in the presence of the DESs. Since ChCl:U and ChCl:G DESs are nontoxic, biodegradable, biorenewable and “green” solvents and provide the elimination of the calcination step of CaO, thus reducing the overall process costs, the non-calcined CaO catalytic systems with these DESs are recommended for further optimization. © 2018 Elsevier B.V.Published version: [https://hdl.handle.net/21.15107/rcub_dais_3694]This is the peer reviewed version of the following article: Troter, D.Z., Todorović, Z.B., Đokić-Stojanović, D.R., Veselinović, L.M., Zdujić, M.V., Veljković, V.B., 2018. Choline chloride-based deep eutectic solvents in CaO-catalyzed ethanolysis of expired sunflower oil. Journal of Molecular Liquids 266, 557–567. [https://doi.org/10.1016/j.molliq.2018.06.106]Supplementary information: [https://hdl.handle.net/21.15107/rcub_dais_3772

Supplementary data for article: Đokić-Stojanović, D. R.; Todorović, Z. B.; Troter, D. Z.; Stamenković, O. S.; Veselinović, L. M.; Zdujić, M. V.; Manojlović, D. D.; Veljković, V. B. Triethanolamine as an Efficient Cosolvent for Biodiesel Production by Cao-Catalyzed Sunflower Oil Ethanolysis: An Optimization Study. Hemijska Industrija 2019, 73 (6), 351–362. https://doi.org/10.2298/HEMIND190822033D

Supplementary material for: [https://doi.org/10.2298/HEMIND190822033D]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/3797

Triethanolamine as an efficient cosolvent for biodiesel production by cao-catalyzed sunflower oil ethanolysis: An optimization study

Triethanolamine was applied as an efficient „green“ cosolvent for biodiesel production by CaO-catalyzed ethanolysis of sunflower oil. The reaction was conducted in a batch stirred reactor and optimized with respect to the reaction temperature (61.6-78.4 °C), the ethanol-to-oil molar ratio (7:1-17:1) and the cosolvent loading (3-36 % of the oil weight) by using a rotatable central composite design (RCCD) combined with the response surface methodology (RSM). The optimal reaction conditions were found to be: the ethanol-to-oil molar ratio of 9:1, the reaction temperature of 75 °C and the cosolvent loading of 30 % to oil weight, which resulted in the predicted and actual fatty acid ethyl ester (FAEE) contents of 98.8 % and 97.9±1.3 %, respectively, achieved within only 20 min of the reaction. Also, high FAEE contents were obtained with expired sunflower oil, hempseed oil and waste lard. X-ray diffraction analysis (XRD) was used to understand the changes in the CaO phase. The CaO catalyst can be used without any treatment in two consecutive cycles. Due to the calcium leaching into the product, an additional purification stage must be included in the overall process.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3798

Supplementary data for article: Đokić-Stojanović, D. R.; Todorović, Z. B.; Troter, D. Z.; Stamenković, O. S.; Veselinović, L. M.; Zdujić, M. V.; Manojlović, D. D.; Veljković, V. B. Triethanolamine as an Efficient Cosolvent for Biodiesel Production by Cao-Catalyzed Sunflower Oil Ethanolysis: An Optimization Study. Hemijska Industrija 2019, 73 (6), 351–362. https://doi.org/10.2298/HEMIND190822033D

Supplementary material for: [https://doi.org/10.2298/HEMIND190822033D]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/3797

Heterogeno katalizovana etanoliza suncokretovog ulja u prisustvu polietilen glikola, etil acetata i dietil etra kao kosolvenata

A heterogeneous reaction process using propylene glycol (PEG), ethyl acetate and diethyl ether as cosolvents for the transesterification of sunflower oil with ethanol in the presence of calcium oxide as a catalyst has been developed. Significant results were obtained with propylene glycol as a cosolvent. Under determined reaction conditions (CaO concentration, based on the oil weight 1.3736 mol∙dm-3; temperature 70°C; and ethanol-to-oil molar ratio 12:1), the conversion of sunflower oil to fatty acid ethyl esters (FAEE) exceeded 98% after 120 min, which was 2 times faster than transesterification of sunflower oil without a cosolvent. After initially enhanced ethanolysis, after 180 min ethyl acetate and diethyl ether negatively influenced the reaction rate and the FAEE yield.U radu je opisana heterogena transesterifikacija suncokretovog ulja sa etanolom i kalcijum oksidom kao katalizatorom u prisustvu polietilen glikola (PEG), etil acetata i dietil etra kao kosolvenata. Najpovoljniji rezultati su dobijeni sa polietilen glikolom kao kosolventom gde je, pod određenim reakcionim uslovima (koncentracija CaO, računata u odnosu na masu ulja 1.3736 mol∙dm-3, temperatura 70°C i molarni odnos etanol:ulje 12:1), konverzija suncokretovog ulja u etil estre masnih kiselina (FAEE) dostigla vrednost od 98% nakon 120 minuta, što je 2 puta brže od transesterifikacije suncokretovog ulja bez prisustva kosolventa. Etil acetat i dietil etar poboljšavaju reakciju etanolize na početku, ali, kako reakcija napreduje, posle 180 minuta, njihovo prisustvo u reakcionoj smeši negativno utiče na brzinu reakcije i prinos etil estrara masnih kiselina (FAEE)

The physicochemical and thermodynamic properties of the choline chloride-based deep eutectic solvents

This paper reports the physicochemical (density, dynamic viscosity, electrical conductivity and refractive index) and the thermodynamic (thermal expansion coefficient, molecular volume, lattice energy and heat capacity) properties of several choline chloride (ChCl) based deep eutectic solvents (DESs), with 1:2 mole ratio, respectively:ChCl:propylene glycol, ChCl:1,3-dimethyl-urea and ChCl:thiourea, at atmospheric pressure as a function of temperature over the range of 293.15-363.15 K. Their properties were also compared with those of some already characterized ChCl-based DESs, namely ChCl:ethylene glycol, ChCl:glycerol and ChCl:urea (1:2 mole ratio). Density, viscosity and refractive index of all DESs decrease with the increasing temperature while the electrical conductivity increases. Viscosity and conductivity of the tested DESs were fitted by both Arrhenius-type and Vogel-Tamman-Fulcher equations. The changes of molar enthalpy, entropy and Gibbs energy of activation, determined using the Eyring theory, demonstrated the interactional factor as predominant over the structural factor for all DES systems. The fractional Walden rule, used to correlate molar conductivity and viscosity, showed an excellent linear behaviour. It was shown that ChCl:propylene glycol DES had properties similar to ChCl:ethylene glycol and ChCl:glycerol DESs. However, the properties (density, viscosity and electrical conductivity) of ChCl:1,3-dimethylurea and ChCl::thiourea DESs were inferior to those of the ChCl:urea DES

Influence of various cosolvents on the calcium oxide-catalyzed ethanolysis of sunflower oil

Ten organic solvents (triethanolamine, diethanolamine, ethylene glycol, methyl ethyl ketone, n-hexane, triethylamine, ethylene glycol dimethyl ether, glycerol, tetrahydrofuran and dioxane) were applied as cosolvents in the CaO-catalyzed ethanolysis of sunflower oil performed in a batch stirred reactor under the following reaction conditions: temperature 70 °C, ethanol-to-oil mole ratio 12:1, initial catalyst concentration 1.374 mol·L -1 and amount of cosolvent 20 % based on the oil amount. The main goals were to assess the effect of the used cosolvents on the synthesis of fatty acid ethyl esters (FAEE) and to select the most efficient one with respect to the final FAEE content, reaction duration and safety profile. In the absence of any cosolvent, the reaction was rather slow, providing a FAEE content of only 89.7±1.7 % after 4 h. Of the tested cosolvents, diethanolamine, triethanolamine and ethylene glycol significantly accelerated the ethanolysis reaction, whereby the last two provided a final FAEE content of 93.1±2.1 and 94.1±1.5 %, respectively, within 0.5 h. However, because of its safety profile, triethanolamine was selected as the best cosolvent for the ethanolysis of sunflower oil catalyzed by calcined CaO

Uticaj kosolvenata na etanolizu suncokretovog ulja katalizovanoj kalcijum-oksidom: doktorske disertacije

In this dissertation, the influence of different organic solvents (triethanolamine, diethanolamine, ethylene glycol, methyl ethyl ketone, n-hexane, triethylamine, ethylene glycol dimethyl ether, glycerol, tetrahydrofuran and dioxane) as cosolventethanolysis of sunflower oil catalyzed by calcinated CaO. Ethanolysis was performed as a heterogeneous base-catalyzed process in which calcinated CaO in a stirred batch reactor was used as a catalyst. The reaction conditions were: temperature 70 °C, ethanol:oil molar ratio 12:1, catalyst concentration 1.374 mol·dm-3 and cosolvent amount 20% by weight of oil. Without cosolvent, the reaction is relatively slow, because the EEMK content of 89.7 ± 1.73% was obtained only after 4 h of reaction. Of the cosolvents used, only diethanolamine, triethanolamine and ethylene glycol had a positive effect on the rate of ethanolysis reaction, with the use of triethanolamine and ethylene glycol achieved the highest EEMK content of 93.1±2.1 and 94.1± 1.5%, respectively, after 0,5 h reaction. Based on the experimental results, triethanolamine and the cosolvent that had the greatest positive effect on the rate of the transesterification reaction of the safety profile were selected, triethanolamine was selected as the best cosolvent of the reaction ethanolysis reaction catalyzed by CaO. The reaction with triethanolamine was optimized with respect to temperature (61,6-78,4 °C), ethanol:oil molar ratio (7:1-17:1) and cosolvent amount (3-36%, by weight of oil) using a central composite rotatable experimental design (RCCD) in combination with a response surface methodology (RSM). The optimal reaction conditions are: molar ratio ethanol:oil 9:1, temperature 75 °C and cosolvent amount 30% ( to the mass of oil), where the predicted value of EEMK content after only 20 min of reaction was 98,8%, while the experimentally obtained value was 97,9 ± 1,3%. High EEMK contents were also obtained during the application of expired sunflower oil, hemp oil and waste lard. X-ray diffraction analysis (XRD) was used to understand the structural changes of CaO catalysts. The CaO catalyst could be used without any additional treatment in two consecutive cycles. Due to the leaching of calcium into the product, an additional purification process must be included in the entire production process

The physicochemical and thermodynamic properties of the choline chloride-based deep eutectic solvents

This paper reports the physicochemical (density, dynamic viscosity, electrical conductivity and refractive index) and the thermodynamic (thermal expansion coefficient, molecular volume, lattice energy and heat capacity) properties of several choline chloride (ChCl) based deep eutectic solvents (DESs), with 1:2 mole ratio, respectively: ChCl:propylene glycol, ChCl:1,3-dimethylurea and ChCl:thiourea, at atmospheric pressure as a function of temperature over the range of 293.15–363.15 K. Their properties were also compared with those of some already characterized ChCl-based DESs, namely ChCl:ethylene glycol, ChCl:glycerol and ChCl:urea (1:2 mole ratio). Density, viscosity and refractive index of all DESs decrease with the increasing temperature while the electrical conductivity increases. Viscosity and conductivity of the tested DESs were fitted by both Arrhenius-type and Vogel–Tamman–Fulcher equations. The changes of molar enthalpy, entropy and Gibbs energy of activation, determined using the Eyring theory, demonstrated the interactional factor as predominant over the structural factor for all DES systems. The fractional Walden rule, used to correlate molar conductivity and viscosity, showed an excellent linear behaviour. It was shown that ChCl:propylene glycol DES had properties similar to ChCl:ethylene glycol and ChCl:glycerol DESs. However, the properties (density, viscosity and electrical conductivity) of ChCl:1,3-dimethylurea and ChCl: :thiourea DESs were inferior to those of the ChCl:urea DES. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 45001