TY  - JOUR
AU  - Kesić, Željka
AU  - Lukić, Ivana
AU  - Zdujić, Miodrag
AU  - Jovalekić, Čedomir
AU  - Liu, Hui
AU  - Skala, Dejan
PY  - 2015
UR  - http://dais.sanu.ac.rs/123456789/3542
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2606
AB  - The goal of this study was to prepare a CaO·ZnO catalyst containing a small amount of K2CO3 and analyze its activity for biodiesel synthesis. The catalyst was prepared using the following procedure: CaO and ZnO (mole ratio of 1:2), water and K2CO3 (in various amounts) were mechanochemically treated and after milling heated at 700 °C in air atmosphere for obtaining mixed CaO·ZnO/xK2CO3 oxides (x = 0, 1, 2 and 4 mol of K2CO3 per 10 mol of CaO). All the samples were characterized by X-ray diffraction (XRD), inductively coupled plasma (ICP), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), infrared spectroscopy (FTIR), scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS), particle size laser diffraction (PSLD) distribution, solubility measurement of Ca, Zn and K ions in methanol as well as by determination of their alkalinity (Hammett Indicator method). Prepared CaO·ZnO/xK2CO3 composite powders were tested as catalysts for methanolysis of sunflower oil at 70 °C using mole ratio of sunflower oil to methanol of 1:10 and with 2 mass% of catalyst based on oil weight. The presence of K2CO3 in prepared samples was found to increase the activity of catalyst, and that such effect is caused by homogeneous-heterogeneous catalysis of biodiesel synthesis. © 2015, CI and CEQ. All Rights Reserved.
PB  - Belgrade: Association of the Chemical Engineers of Serbia
T2  - Chemical Industry and Chemical Engineering Quarterly
T1  - Mechanochemical synthesis of CaO·ZnO·K2CO3 catalyst: Characterization and activity for methanolysis of sunflower oil
VL  - 21
IS  - 1
SP  - 1
EP  - 12
DO  - 10.2298/CICEQ131026041K
ER  - 

@article{
author = "Kesić, Željka and Lukić, Ivana and Zdujić, Miodrag and Jovalekić, Čedomir and Liu, Hui and Skala, Dejan",
year = "2015",
abstract = "The goal of this study was to prepare a CaO·ZnO catalyst containing a small amount of K2CO3 and analyze its activity for biodiesel synthesis. The catalyst was prepared using the following procedure: CaO and ZnO (mole ratio of 1:2), water and K2CO3 (in various amounts) were mechanochemically treated and after milling heated at 700 °C in air atmosphere for obtaining mixed CaO·ZnO/xK2CO3 oxides (x = 0, 1, 2 and 4 mol of K2CO3 per 10 mol of CaO). All the samples were characterized by X-ray diffraction (XRD), inductively coupled plasma (ICP), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), infrared spectroscopy (FTIR), scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS), particle size laser diffraction (PSLD) distribution, solubility measurement of Ca, Zn and K ions in methanol as well as by determination of their alkalinity (Hammett Indicator method). Prepared CaO·ZnO/xK2CO3 composite powders were tested as catalysts for methanolysis of sunflower oil at 70 °C using mole ratio of sunflower oil to methanol of 1:10 and with 2 mass% of catalyst based on oil weight. The presence of K2CO3 in prepared samples was found to increase the activity of catalyst, and that such effect is caused by homogeneous-heterogeneous catalysis of biodiesel synthesis. © 2015, CI and CEQ. All Rights Reserved.",
publisher = "Belgrade: Association of the Chemical Engineers of Serbia",
journal = "Chemical Industry and Chemical Engineering Quarterly",
title = "Mechanochemical synthesis of CaO·ZnO·K2CO3 catalyst: Characterization and activity for methanolysis of sunflower oil",
volume = "21",
number = "1",
pages = "1-12",
doi = "10.2298/CICEQ131026041K"
}

Kesić, Ž., Lukić, I., Zdujić, M., Jovalekić, Č., Liu, H.,& Skala, D.. (2015). Mechanochemical synthesis of CaO·ZnO·K2CO3 catalyst: Characterization and activity for methanolysis of sunflower oil. in Chemical Industry and Chemical Engineering Quarterly
Belgrade: Association of the Chemical Engineers of Serbia., 21(1), 1-12.
https://doi.org/10.2298/CICEQ131026041K

Kesić Ž, Lukić I, Zdujić M, Jovalekić Č, Liu H, Skala D. Mechanochemical synthesis of CaO·ZnO·K2CO3 catalyst: Characterization and activity for methanolysis of sunflower oil. in Chemical Industry and Chemical Engineering Quarterly. 2015;21(1):1-12.
doi:10.2298/CICEQ131026041K .

Kesić, Željka, Lukić, Ivana, Zdujić, Miodrag, Jovalekić, Čedomir, Liu, Hui, Skala, Dejan, "Mechanochemical synthesis of CaO·ZnO·K2CO3 catalyst: Characterization and activity for methanolysis of sunflower oil" in Chemical Industry and Chemical Engineering Quarterly, 21, no. 1 (2015):1-12,
https://doi.org/10.2298/CICEQ131026041K . .

TY  - JOUR
AU  - Lukić, Ivana
AU  - Kesić, Željka
AU  - Maksimović, Svetolik
AU  - Zdujić, Miodrag
AU  - Krstić, Jugoslav
AU  - Skala, Dejan
PY  - 2014
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1461
AB  - The kinetics of heterogeneous methanolysis of sunflower oil was studied at 60 °C using mechanochemically synthesized CaO·ZnO as catalyst. The influence of agitation speed, catalyst amount, and methanol-to-oil molar ratio on the rate of reaction was analyzed. The rate of the process depends on the two resistances - mass transfer of triglycerides to the catalyst surface and chemical reaction on the catalyst surface, which are defined as the values of the overall triglyceride volumetric mass transfer coefficient, kmt,TG, and the effective pseudo first-order reaction rate constant, k, respectively. These kinetic parameters actually determine the value of the apparent reaction rate constant, kapp, the time dependence of which is defined by the change of triglyceride (TG) conversion. A kinetic model is proposed and the model parameters are determined.
AB  - Kinetika heterogene metanolize suncokretovog ulja je ispitivana na 60 °C korišćenjem CaO·ZnO katalizatora koji je sintetizovan mehanohemijskim putem. Analiziran je uticaj intenziteta mešanja, mase korišćenog katalizatora u sintezi i različitog molskog odnosa metanola i ulja na brzinu metanolize. Brzina procesa metanolize zavisi od dva otpora - otpora prenosu mase triglicerida do površine katalizatora i otpora brzini hemijske reakcije na površini katalizatora. Oba otpora određuju vrednost ukupnog zapreminskog koeficijenta prenosa mase triglicerida, kmt,TG, odnosno efektivne vrednosti konstante brzine hemijske reakcije pseudo-prvog reda, k. Ovi kinetički parametri određuju vrednost prividne konstante brzine procesa metanolize, kapp, koja se menja sa vremenom u zavisnosti od ostvareneog stepena konverzije triglicerida (TG). Predložen je odgovarajući model kojim je moguće definisati brzinu metanolize i određeni su odgovarajući parametri ovog modela.
PB  - Belgrade : Association of the Chemical Engineers of Serbia
T2  - Chemical Industry and Chemical Engineering Quarterly
T1  - Kinetics of heterogeneous methanolysis of sunflower oil with CaO·ZnO catalyst: Influence of different hydrodynamic conditions
T1  - Kinetika heterogene metanolize suncokretovog ulja sa CaO·ZnO kao katalizatorom - uticaj različitih hidrodinamičkih uslova
VL  - 20
IS  - 3
SP  - 425
EP  - 439
DO  - 10.2298/CICEQ130514025L
ER  - 

@article{
author = "Lukić, Ivana and Kesić, Željka and Maksimović, Svetolik and Zdujić, Miodrag and Krstić, Jugoslav and Skala, Dejan",
year = "2014",
abstract = "The kinetics of heterogeneous methanolysis of sunflower oil was studied at 60 °C using mechanochemically synthesized CaO·ZnO as catalyst. The influence of agitation speed, catalyst amount, and methanol-to-oil molar ratio on the rate of reaction was analyzed. The rate of the process depends on the two resistances - mass transfer of triglycerides to the catalyst surface and chemical reaction on the catalyst surface, which are defined as the values of the overall triglyceride volumetric mass transfer coefficient, kmt,TG, and the effective pseudo first-order reaction rate constant, k, respectively. These kinetic parameters actually determine the value of the apparent reaction rate constant, kapp, the time dependence of which is defined by the change of triglyceride (TG) conversion. A kinetic model is proposed and the model parameters are determined., Kinetika heterogene metanolize suncokretovog ulja je ispitivana na 60 °C korišćenjem CaO·ZnO katalizatora koji je sintetizovan mehanohemijskim putem. Analiziran je uticaj intenziteta mešanja, mase korišćenog katalizatora u sintezi i različitog molskog odnosa metanola i ulja na brzinu metanolize. Brzina procesa metanolize zavisi od dva otpora - otpora prenosu mase triglicerida do površine katalizatora i otpora brzini hemijske reakcije na površini katalizatora. Oba otpora određuju vrednost ukupnog zapreminskog koeficijenta prenosa mase triglicerida, kmt,TG, odnosno efektivne vrednosti konstante brzine hemijske reakcije pseudo-prvog reda, k. Ovi kinetički parametri određuju vrednost prividne konstante brzine procesa metanolize, kapp, koja se menja sa vremenom u zavisnosti od ostvareneog stepena konverzije triglicerida (TG). Predložen je odgovarajući model kojim je moguće definisati brzinu metanolize i određeni su odgovarajući parametri ovog modela.",
publisher = "Belgrade : Association of the Chemical Engineers of Serbia",
journal = "Chemical Industry and Chemical Engineering Quarterly",
title = "Kinetics of heterogeneous methanolysis of sunflower oil with CaO·ZnO catalyst: Influence of different hydrodynamic conditions, Kinetika heterogene metanolize suncokretovog ulja sa CaO·ZnO kao katalizatorom - uticaj različitih hidrodinamičkih uslova",
volume = "20",
number = "3",
pages = "425-439",
doi = "10.2298/CICEQ130514025L"
}

Lukić, I., Kesić, Ž., Maksimović, S., Zdujić, M., Krstić, J.,& Skala, D.. (2014). Kinetics of heterogeneous methanolysis of sunflower oil with CaO·ZnO catalyst: Influence of different hydrodynamic conditions. in Chemical Industry and Chemical Engineering Quarterly
Belgrade : Association of the Chemical Engineers of Serbia., 20(3), 425-439.
https://doi.org/10.2298/CICEQ130514025L

Lukić I, Kesić Ž, Maksimović S, Zdujić M, Krstić J, Skala D. Kinetics of heterogeneous methanolysis of sunflower oil with CaO·ZnO catalyst: Influence of different hydrodynamic conditions. in Chemical Industry and Chemical Engineering Quarterly. 2014;20(3):425-439.
doi:10.2298/CICEQ130514025L .

Lukić, Ivana, Kesić, Željka, Maksimović, Svetolik, Zdujić, Miodrag, Krstić, Jugoslav, Skala, Dejan, "Kinetics of heterogeneous methanolysis of sunflower oil with CaO·ZnO catalyst: Influence of different hydrodynamic conditions" in Chemical Industry and Chemical Engineering Quarterly, 20, no. 3 (2014):425-439,
https://doi.org/10.2298/CICEQ130514025L . .

TY  - JOUR
AU  - Lukić, Ivana
AU  - Kesic, Zeljka
AU  - Maksimović, Svetolik
AU  - Zdujić, Miodrag
AU  - Liu, Hui
AU  - Krstić, Jugoslav
AU  - Skala, Dejan
PY  - 2013
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1180
AB  - The kinetics of heterogeneous methanolysis of sunflower oil and used vegetable oil were studied at different temperatures, ranging from 60 to 96 degrees C using CaO center dot ZnO as catalyst (2 wt% on the basis of oil) and methanol to oil molar ratio of 10:1. Heterogeneous CaO center dot ZnO catalyst was synthesized by mechanochemical treatment of CaO and ZnO powder mixture with the addition of water necessary for the formation of corresponding mixed hydroxides, and their calcination at 700 degrees C in air. It was shown that kinetics of overall process could be described as pseudo-first order reaction. For the sunflower oil methanolysis at 60 and 70 degrees C, the rate of process at the beginning of biodiesel synthesis was limited by triglycerides mass transfer to the catalyst surface, and after that it is governed by the rate of chemical reaction at catalyst surface. At higher temperatures the influence of mass transfer resistance is almost negligible implying that the rate of chemical reaction determines the overall kinetic of biodiesel synthesis. In the case of used vegetable oil, the influence of mass transfer resistance was not observed either at higher or lower temperature. The kinetic model that describes the whole process well was proposed, and it comprises both the triglycerides mass transfer and chemical reaction controlled regime. The overall volumetric mass transfer coefficient was defined, assuming that it depends on the conversion of triglycerides.
PB  - Elsevier Sci Ltd, Oxford
T2  - Fuel
T1  - Kinetics of sunflower and used vegetable oil methanolysis catalyzed by CaO center dot ZnO
VL  - 113
SP  - 367
EP  - 378
DO  - 10.1016/j.fuel.2013.05.093
ER  - 

@article{
author = "Lukić, Ivana and Kesic, Zeljka and Maksimović, Svetolik and Zdujić, Miodrag and Liu, Hui and Krstić, Jugoslav and Skala, Dejan",
year = "2013",
abstract = "The kinetics of heterogeneous methanolysis of sunflower oil and used vegetable oil were studied at different temperatures, ranging from 60 to 96 degrees C using CaO center dot ZnO as catalyst (2 wt% on the basis of oil) and methanol to oil molar ratio of 10:1. Heterogeneous CaO center dot ZnO catalyst was synthesized by mechanochemical treatment of CaO and ZnO powder mixture with the addition of water necessary for the formation of corresponding mixed hydroxides, and their calcination at 700 degrees C in air. It was shown that kinetics of overall process could be described as pseudo-first order reaction. For the sunflower oil methanolysis at 60 and 70 degrees C, the rate of process at the beginning of biodiesel synthesis was limited by triglycerides mass transfer to the catalyst surface, and after that it is governed by the rate of chemical reaction at catalyst surface. At higher temperatures the influence of mass transfer resistance is almost negligible implying that the rate of chemical reaction determines the overall kinetic of biodiesel synthesis. In the case of used vegetable oil, the influence of mass transfer resistance was not observed either at higher or lower temperature. The kinetic model that describes the whole process well was proposed, and it comprises both the triglycerides mass transfer and chemical reaction controlled regime. The overall volumetric mass transfer coefficient was defined, assuming that it depends on the conversion of triglycerides.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Fuel",
title = "Kinetics of sunflower and used vegetable oil methanolysis catalyzed by CaO center dot ZnO",
volume = "113",
pages = "367-378",
doi = "10.1016/j.fuel.2013.05.093"
}

Lukić, I., Kesic, Z., Maksimović, S., Zdujić, M., Liu, H., Krstić, J.,& Skala, D.. (2013). Kinetics of sunflower and used vegetable oil methanolysis catalyzed by CaO center dot ZnO. in Fuel
Elsevier Sci Ltd, Oxford., 113, 367-378.
https://doi.org/10.1016/j.fuel.2013.05.093

Lukić I, Kesic Z, Maksimović S, Zdujić M, Liu H, Krstić J, Skala D. Kinetics of sunflower and used vegetable oil methanolysis catalyzed by CaO center dot ZnO. in Fuel. 2013;113:367-378.
doi:10.1016/j.fuel.2013.05.093 .

Lukić, Ivana, Kesic, Zeljka, Maksimović, Svetolik, Zdujić, Miodrag, Liu, Hui, Krstić, Jugoslav, Skala, Dejan, "Kinetics of sunflower and used vegetable oil methanolysis catalyzed by CaO center dot ZnO" in Fuel, 113 (2013):367-378,
https://doi.org/10.1016/j.fuel.2013.05.093 . .

TY  - CONF
AU  - Kesić, Željka
AU  - Lukić, Ivana
AU  - Zdujić, Miodrag
AU  - Jovalekić, Čedomir
AU  - Shao, Yong
AU  - Liu, Hui
AU  - Skala, Dejan
PY  - 2013
UR  - http://dais.sanu.ac.rs/123456789/423
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2842
AB  - The mixed oxide of CaO·ZnO and K2CO3 were prepared by ball milling of CaO and ZnO powders and water, with addition of K2CO3 and afterward by calcination at 700 oC. Influence of different molar ratio of K2CO3 and CaO (x=1, 2 and 4 moles of K2CO3 per 10 moles of CaO) was studied . The prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), infrared spectroscopy (FTIR), scanningelectron microscopy/energy-dispersive spectroscopy (SEM/EDS) and the particle size laser diffraction (PSLD) distribution. The addition of smaller amount of K2CO3 at the beginning of ball miling (x≤2), favors the formation of calcium zinc hydroxide hydrate, while it is not the case when K2CO3 larger addition was used (x > 2). A larger amount of potassium carbonate in the initialcomposition of powder mixture negatively affected formation of CaZn2(OH)6·2H2O. Bimodal distribution were detected for all samples after calcination at 700 oC and the results showed that the distribution of elements in the bulk is not homogeneous and that surface of formed mixed oxide CaO.ZnO (XPS analysis) after calcination is mainly covered by potassium species. That evidence indicate that the K2CO3 was not fully incorporated into the matrix. Prepared samples could be used for methanolysis of vegetable oil and fatty acid methyl esters (FAME, i.e. biodiesel) synthesis.
PB  - Belgrade : Serbian Ceramic Society
C3  - Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts : II Serbian Ceramic Society Conference, Sep 30th-Oct 1st, 2013, Belgrade
T1  - Biodiesel synthesis based on CaO·ZnO.K2CO3 as catalyst
SP  - 46
EP  - 46
UR  - https://hdl.handle.net/21.15107/rcub_dais_423
ER  - 

@conference{
author = "Kesić, Željka and Lukić, Ivana and Zdujić, Miodrag and Jovalekić, Čedomir and Shao, Yong and Liu, Hui and Skala, Dejan",
year = "2013",
abstract = "The mixed oxide of CaO·ZnO and K2CO3 were prepared by ball milling of CaO and ZnO powders and water, with addition of K2CO3 and afterward by calcination at 700 oC. Influence of different molar ratio of K2CO3 and CaO (x=1, 2 and 4 moles of K2CO3 per 10 moles of CaO) was studied . The prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), infrared spectroscopy (FTIR), scanningelectron microscopy/energy-dispersive spectroscopy (SEM/EDS) and the particle size laser diffraction (PSLD) distribution. The addition of smaller amount of K2CO3 at the beginning of ball miling (x≤2), favors the formation of calcium zinc hydroxide hydrate, while it is not the case when K2CO3 larger addition was used (x > 2). A larger amount of potassium carbonate in the initialcomposition of powder mixture negatively affected formation of CaZn2(OH)6·2H2O. Bimodal distribution were detected for all samples after calcination at 700 oC and the results showed that the distribution of elements in the bulk is not homogeneous and that surface of formed mixed oxide CaO.ZnO (XPS analysis) after calcination is mainly covered by potassium species. That evidence indicate that the K2CO3 was not fully incorporated into the matrix. Prepared samples could be used for methanolysis of vegetable oil and fatty acid methyl esters (FAME, i.e. biodiesel) synthesis.",
publisher = "Belgrade : Serbian Ceramic Society",
journal = "Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts : II Serbian Ceramic Society Conference, Sep 30th-Oct 1st, 2013, Belgrade",
title = "Biodiesel synthesis based on CaO·ZnO.K2CO3 as catalyst",
pages = "46-46",
url = "https://hdl.handle.net/21.15107/rcub_dais_423"
}

Kesić, Ž., Lukić, I., Zdujić, M., Jovalekić, Č., Shao, Y., Liu, H.,& Skala, D.. (2013). Biodiesel synthesis based on CaO·ZnO.K2CO3 as catalyst. in Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts : II Serbian Ceramic Society Conference, Sep 30th-Oct 1st, 2013, Belgrade
Belgrade : Serbian Ceramic Society., 46-46.
https://hdl.handle.net/21.15107/rcub_dais_423

Kesić Ž, Lukić I, Zdujić M, Jovalekić Č, Shao Y, Liu H, Skala D. Biodiesel synthesis based on CaO·ZnO.K2CO3 as catalyst. in Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts : II Serbian Ceramic Society Conference, Sep 30th-Oct 1st, 2013, Belgrade. 2013;:46-46.
https://hdl.handle.net/21.15107/rcub_dais_423 .

Kesić, Željka, Lukić, Ivana, Zdujić, Miodrag, Jovalekić, Čedomir, Shao, Yong, Liu, Hui, Skala, Dejan, "Biodiesel synthesis based on CaO·ZnO.K2CO3 as catalyst" in Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts : II Serbian Ceramic Society Conference, Sep 30th-Oct 1st, 2013, Belgrade (2013):46-46,
https://hdl.handle.net/21.15107/rcub_dais_423 .

TY  - CONF
AU  - Kesić, Željka
AU  - Lukić, Ivana
AU  - Zdujić, Miodrag
AU  - Jovalekić, Čedomir
AU  - Shao, Yong
AU  - Liu, Hui
AU  - Skala, Dejan
PY  - 2013
UR  - http://dais.sanu.ac.rs/123456789/422
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2843
AB  - The mixed oxide of CaO·ZnO and K2CO3 were prepared by ball milling of CaO and ZnO powders and water, with addition of K2CO3 and afterward by calcination at 700 oC. Influence of different molar ratio of K2CO3 and CaO (x=1, 2 and 4 moles of K2CO3 per 10 moles of CaO) was studied . The prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), infrared spectroscopy (FTIR), scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS) and the particle size laser diffraction (PSLD) distribution. The addition of smaller amount of K2CO3 at the beginning of ball miling (x≤2), favors the formation of calcium zinc hydroxide hydrate, while it is not the case when K2CO3 larger addition was used (x > 2). A larger amount of potassium carbonate in the initial composition of powder mixture negatively affected formation of CaZn2(OH)6·2H2O. Bimodal distribution were detected for all samples after calcination at 700 oC and the results showed that the distribution of elements in the bulk is not homogeneous and that surface of formed mixed oxide CaO.ZnO (XPS analysis) after calcination is mainly covered by potassium species. That evidence indicate that the K2CO3 was not fully incorporated into the matrix. Prepared samples could be used for methanolysis of vegetable oil and fatty acid methyl esters (FAME, i.e. biodiesel) synthesis.
PB  - Belgrade : Serbian Ceramic Society
C3  - Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts : II Serbian Ceramic Society Conference, Sep 30th-Oct 1st, 2013, Belgrade
T1  - Characterization of mechanochemically synthesized CaO·ZnO.K2CO3
SP  - 45
EP  - 45
UR  - https://hdl.handle.net/21.15107/rcub_dais_422
ER  - 

@conference{
author = "Kesić, Željka and Lukić, Ivana and Zdujić, Miodrag and Jovalekić, Čedomir and Shao, Yong and Liu, Hui and Skala, Dejan",
year = "2013",
abstract = "The mixed oxide of CaO·ZnO and K2CO3 were prepared by ball milling of CaO and ZnO powders and water, with addition of K2CO3 and afterward by calcination at 700 oC. Influence of different molar ratio of K2CO3 and CaO (x=1, 2 and 4 moles of K2CO3 per 10 moles of CaO) was studied . The prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), infrared spectroscopy (FTIR), scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS) and the particle size laser diffraction (PSLD) distribution. The addition of smaller amount of K2CO3 at the beginning of ball miling (x≤2), favors the formation of calcium zinc hydroxide hydrate, while it is not the case when K2CO3 larger addition was used (x > 2). A larger amount of potassium carbonate in the initial composition of powder mixture negatively affected formation of CaZn2(OH)6·2H2O. Bimodal distribution were detected for all samples after calcination at 700 oC and the results showed that the distribution of elements in the bulk is not homogeneous and that surface of formed mixed oxide CaO.ZnO (XPS analysis) after calcination is mainly covered by potassium species. That evidence indicate that the K2CO3 was not fully incorporated into the matrix. Prepared samples could be used for methanolysis of vegetable oil and fatty acid methyl esters (FAME, i.e. biodiesel) synthesis.",
publisher = "Belgrade : Serbian Ceramic Society",
journal = "Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts : II Serbian Ceramic Society Conference, Sep 30th-Oct 1st, 2013, Belgrade",
title = "Characterization of mechanochemically synthesized CaO·ZnO.K2CO3",
pages = "45-45",
url = "https://hdl.handle.net/21.15107/rcub_dais_422"
}

Kesić, Ž., Lukić, I., Zdujić, M., Jovalekić, Č., Shao, Y., Liu, H.,& Skala, D.. (2013). Characterization of mechanochemically synthesized CaO·ZnO.K2CO3. in Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts : II Serbian Ceramic Society Conference, Sep 30th-Oct 1st, 2013, Belgrade
Belgrade : Serbian Ceramic Society., 45-45.
https://hdl.handle.net/21.15107/rcub_dais_422

Kesić Ž, Lukić I, Zdujić M, Jovalekić Č, Shao Y, Liu H, Skala D. Characterization of mechanochemically synthesized CaO·ZnO.K2CO3. in Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts : II Serbian Ceramic Society Conference, Sep 30th-Oct 1st, 2013, Belgrade. 2013;:45-45.
https://hdl.handle.net/21.15107/rcub_dais_422 .

Kesić, Željka, Lukić, Ivana, Zdujić, Miodrag, Jovalekić, Čedomir, Shao, Yong, Liu, Hui, Skala, Dejan, "Characterization of mechanochemically synthesized CaO·ZnO.K2CO3" in Advanced Ceramics and Application : new frontiers in multifunctional material science and processing : program and the book of abstracts : II Serbian Ceramic Society Conference, Sep 30th-Oct 1st, 2013, Belgrade (2013):45-45,
https://hdl.handle.net/21.15107/rcub_dais_422 .

TY  - CONF
AU  - Kesić, Željka
AU  - Lukić, Ivana
AU  - Zdujić, Miodrag
AU  - Jovanović, Dušan M.
AU  - Liu, Hui
AU  - Skala, Dejan
PY  - 2012
UR  - http://dais.sanu.ac.rs/123456789/505
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2844
AB  - Room temperature ball milling of CaO and ZnO powder mixture (using molar ratio of CaO:ZnO of 1:2) with the addition of stoichiometrically required amount of water to form calcium zinc hydroxide hydrate (CaZn2(OH)6•2H2O) and subsequent calcination at 700 oC was conducted. In order to improve basicity of mixed oxides, calcium zinc hydroxide hydrate was modified by the addition of promoters. The addition of promoter in initial powder mixture such as K2CO3 and KOH (with molar ratio of promoter to CaO of 1:10) was shown to effect the mechanochemical reaction. The prepared catalysts were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), base strength using Hammett indicator method and scanning electron microscopy (SEM and SEM-EDS). The results showed that, during mechanochemical treatment, CaO, ZnO and H2O reacted rapidly to form CaZn2(OH)6•2H2O, and this was the same when promoters were used. Only difference was in basicity of the catalysts, and opposite of the expected, results showed that the addition of promoters did not cause an increase of basicity. On the other hand, addition of KOH to initial powder mixture caused increase of carbonates formation during mechanochemical treatment.
PB  - Belgrade : Serbian Ceramic Society
C3  - The First Serbian Ceramic Society Conference "Advanced Ceramics and Application" May 10-11, 2012: Program and the Book of Abstracts
T1  - Characterization of Mechanochemically Synthesized CaO·ZnO/K2O Mixed Oxides
SP  - 28
EP  - 28
UR  - https://hdl.handle.net/21.15107/rcub_dais_505
ER  - 

@conference{
author = "Kesić, Željka and Lukić, Ivana and Zdujić, Miodrag and Jovanović, Dušan M. and Liu, Hui and Skala, Dejan",
year = "2012",
abstract = "Room temperature ball milling of CaO and ZnO powder mixture (using molar ratio of CaO:ZnO of 1:2) with the addition of stoichiometrically required amount of water to form calcium zinc hydroxide hydrate (CaZn2(OH)6•2H2O) and subsequent calcination at 700 oC was conducted. In order to improve basicity of mixed oxides, calcium zinc hydroxide hydrate was modified by the addition of promoters. The addition of promoter in initial powder mixture such as K2CO3 and KOH (with molar ratio of promoter to CaO of 1:10) was shown to effect the mechanochemical reaction. The prepared catalysts were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), base strength using Hammett indicator method and scanning electron microscopy (SEM and SEM-EDS). The results showed that, during mechanochemical treatment, CaO, ZnO and H2O reacted rapidly to form CaZn2(OH)6•2H2O, and this was the same when promoters were used. Only difference was in basicity of the catalysts, and opposite of the expected, results showed that the addition of promoters did not cause an increase of basicity. On the other hand, addition of KOH to initial powder mixture caused increase of carbonates formation during mechanochemical treatment.",
publisher = "Belgrade : Serbian Ceramic Society",
journal = "The First Serbian Ceramic Society Conference "Advanced Ceramics and Application" May 10-11, 2012: Program and the Book of Abstracts",
title = "Characterization of Mechanochemically Synthesized CaO·ZnO/K2O Mixed Oxides",
pages = "28-28",
url = "https://hdl.handle.net/21.15107/rcub_dais_505"
}

Kesić, Ž., Lukić, I., Zdujić, M., Jovanović, D. M., Liu, H.,& Skala, D.. (2012). Characterization of Mechanochemically Synthesized CaO·ZnO/K2O Mixed Oxides. in The First Serbian Ceramic Society Conference "Advanced Ceramics and Application" May 10-11, 2012: Program and the Book of Abstracts
Belgrade : Serbian Ceramic Society., 28-28.
https://hdl.handle.net/21.15107/rcub_dais_505

Kesić Ž, Lukić I, Zdujić M, Jovanović DM, Liu H, Skala D. Characterization of Mechanochemically Synthesized CaO·ZnO/K2O Mixed Oxides. in The First Serbian Ceramic Society Conference "Advanced Ceramics and Application" May 10-11, 2012: Program and the Book of Abstracts. 2012;:28-28.
https://hdl.handle.net/21.15107/rcub_dais_505 .

Kesić, Željka, Lukić, Ivana, Zdujić, Miodrag, Jovanović, Dušan M., Liu, Hui, Skala, Dejan, "Characterization of Mechanochemically Synthesized CaO·ZnO/K2O Mixed Oxides" in The First Serbian Ceramic Society Conference "Advanced Ceramics and Application" May 10-11, 2012: Program and the Book of Abstracts (2012):28-28,
https://hdl.handle.net/21.15107/rcub_dais_505 .

TY  - CONF
AU  - Lukić, Ivana
AU  - Kesić, Željka
AU  - Zdujić, Miodrag
AU  - Jovanović, Dušan M.
AU  - Liu, Hui
AU  - Skala, Dejan
PY  - 2012
UR  - http://dais.sanu.ac.rs/123456789/513
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/2852
AB  - One of the catalysts that show excellent activity in the methanolysis of vegetable oil under moderate reaction conditions is the mixture of CaO and ZnO oxides. In this study CaO•ZnO catalyst was synthesized by mechanochemical treatment of ZnO and Ca(OH)2 or CaO powder mixture (using molar ratio of CaO (or Ca(OH)2):ZnO of 1:2) with the addition of required water amount to form calcium zinc hydroxide hydrate (CaZn2(OH)6•2H2O) and subsequent calcinations at 700 °C in air atmosphere. The methanolysis of sunflower oil was studied at 60 °C with the molar ratio of methanol to oil of 10:1 and with 2 wt% of catalyst based on oil weight. Characterisation of the catalyst was performed by XRD, TGA/DSC, FTIR, the particle size distribution and Hammett indicator method. The solubility of the catalyst in methanol at 60 °C was also determined by measuring the calcium(II) and zinc(II) concentration. The results showed that whether Ca(OH)2 or CaO were used as a starting material, after calcination an active catalyst composed of CaO and ZnO was obtained. When CaO was used in the starting mixture, basicity was slightly higher, while the amount of present carbonates was lower.
PB  - Belgrade : Serbian Ceramic Society
C3  - The First Serbian Ceramic Society Conference "Advanced Ceramics and Application" May 10-11, 2012: Program and the Book of Abstracts
T1  - Mechanochemical Preparation of CaO·ZnO – catalyst for Fatty Acids Methyl Esters Synthesis
SP  - 18
EP  - 18
UR  - https://hdl.handle.net/21.15107/rcub_dais_513
ER  - 

@conference{
author = "Lukić, Ivana and Kesić, Željka and Zdujić, Miodrag and Jovanović, Dušan M. and Liu, Hui and Skala, Dejan",
year = "2012",
abstract = "One of the catalysts that show excellent activity in the methanolysis of vegetable oil under moderate reaction conditions is the mixture of CaO and ZnO oxides. In this study CaO•ZnO catalyst was synthesized by mechanochemical treatment of ZnO and Ca(OH)2 or CaO powder mixture (using molar ratio of CaO (or Ca(OH)2):ZnO of 1:2) with the addition of required water amount to form calcium zinc hydroxide hydrate (CaZn2(OH)6•2H2O) and subsequent calcinations at 700 °C in air atmosphere. The methanolysis of sunflower oil was studied at 60 °C with the molar ratio of methanol to oil of 10:1 and with 2 wt% of catalyst based on oil weight. Characterisation of the catalyst was performed by XRD, TGA/DSC, FTIR, the particle size distribution and Hammett indicator method. The solubility of the catalyst in methanol at 60 °C was also determined by measuring the calcium(II) and zinc(II) concentration. The results showed that whether Ca(OH)2 or CaO were used as a starting material, after calcination an active catalyst composed of CaO and ZnO was obtained. When CaO was used in the starting mixture, basicity was slightly higher, while the amount of present carbonates was lower.",
publisher = "Belgrade : Serbian Ceramic Society",
journal = "The First Serbian Ceramic Society Conference "Advanced Ceramics and Application" May 10-11, 2012: Program and the Book of Abstracts",
title = "Mechanochemical Preparation of CaO·ZnO – catalyst for Fatty Acids Methyl Esters Synthesis",
pages = "18-18",
url = "https://hdl.handle.net/21.15107/rcub_dais_513"
}

Lukić, I., Kesić, Ž., Zdujić, M., Jovanović, D. M., Liu, H.,& Skala, D.. (2012). Mechanochemical Preparation of CaO·ZnO – catalyst for Fatty Acids Methyl Esters Synthesis. in The First Serbian Ceramic Society Conference "Advanced Ceramics and Application" May 10-11, 2012: Program and the Book of Abstracts
Belgrade : Serbian Ceramic Society., 18-18.
https://hdl.handle.net/21.15107/rcub_dais_513

Lukić I, Kesić Ž, Zdujić M, Jovanović DM, Liu H, Skala D. Mechanochemical Preparation of CaO·ZnO – catalyst for Fatty Acids Methyl Esters Synthesis. in The First Serbian Ceramic Society Conference "Advanced Ceramics and Application" May 10-11, 2012: Program and the Book of Abstracts. 2012;:18-18.
https://hdl.handle.net/21.15107/rcub_dais_513 .

Lukić, Ivana, Kesić, Željka, Zdujić, Miodrag, Jovanović, Dušan M., Liu, Hui, Skala, Dejan, "Mechanochemical Preparation of CaO·ZnO – catalyst for Fatty Acids Methyl Esters Synthesis" in The First Serbian Ceramic Society Conference "Advanced Ceramics and Application" May 10-11, 2012: Program and the Book of Abstracts (2012):18-18,
https://hdl.handle.net/21.15107/rcub_dais_513 .

TY  - JOUR
AU  - Maksimović, Svetolik
AU  - Ivanović, Jasna
AU  - Skala, Dejan
PY  - 2012
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5874
AB  - Supercritical CO2 extraction was studied using dried leaves of Mentha, originated from the northern part of Libya. Leaves were milled and sieved to obtain different average particles (dp = 0.25-0.80 mm). They were treated with supercritical CO2 at 313 K and 10 MPa in order to isolate essential oil. The new approach of supercritical extraction modelling on the basis of proposed "pseudo kinetic model" (PKM) was investigated and compared to most applied in literature Sovova's model. The main focus of these investigation was to determine the influence of particle size on extractions yield and to determine optimal methodology for determination parameters of PKM. Achieved results showed good agreement between both models and experimental results and good prospects for further usage of PKM.
PB  - Elsevier
T2  - Procedia Engineering
T1  - Supercritical extraction of essential oil from Mentha and mathematical modelling- the influence of plant particle size
VL  - 42
SP  - 1767
EP  - 1777
DO  - 10.1016/j.proeng.2012.07.571
ER  - 

@article{
author = "Maksimović, Svetolik and Ivanović, Jasna and Skala, Dejan",
year = "2012",
abstract = "Supercritical CO2 extraction was studied using dried leaves of Mentha, originated from the northern part of Libya. Leaves were milled and sieved to obtain different average particles (dp = 0.25-0.80 mm). They were treated with supercritical CO2 at 313 K and 10 MPa in order to isolate essential oil. The new approach of supercritical extraction modelling on the basis of proposed "pseudo kinetic model" (PKM) was investigated and compared to most applied in literature Sovova's model. The main focus of these investigation was to determine the influence of particle size on extractions yield and to determine optimal methodology for determination parameters of PKM. Achieved results showed good agreement between both models and experimental results and good prospects for further usage of PKM.",
publisher = "Elsevier",
journal = "Procedia Engineering",
title = "Supercritical extraction of essential oil from Mentha and mathematical modelling- the influence of plant particle size",
volume = "42",
pages = "1767-1777",
doi = "10.1016/j.proeng.2012.07.571"
}

Maksimović, S., Ivanović, J.,& Skala, D.. (2012). Supercritical extraction of essential oil from Mentha and mathematical modelling- the influence of plant particle size. in Procedia Engineering
Elsevier., 42, 1767-1777.
https://doi.org/10.1016/j.proeng.2012.07.571

Maksimović S, Ivanović J, Skala D. Supercritical extraction of essential oil from Mentha and mathematical modelling- the influence of plant particle size. in Procedia Engineering. 2012;42:1767-1777.
doi:10.1016/j.proeng.2012.07.571 .

Maksimović, Svetolik, Ivanović, Jasna, Skala, Dejan, "Supercritical extraction of essential oil from Mentha and mathematical modelling- the influence of plant particle size" in Procedia Engineering, 42 (2012):1767-1777,
https://doi.org/10.1016/j.proeng.2012.07.571 . .

TY  - JOUR
AU  - Kesić, Z.
AU  - Lukić, I.
AU  - Zdujić, M.
AU  - Liu, H.
AU  - Skala, Dejan
PY  - 2012
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/5873
AB  - The transesterification of triglycerides (vegetable oil) with methanol using CaO·ZnO mixed oxides catalyst were conducted to produce FAME (Fatty Acid Methyl Esters, i.e. biodiesel). Catalyst was synthesized by ball milling of CaO and ZnO powder mixture (using molar ratio of Ca and Zn of 1:2 and 1:4) with the addition of water, as well as solely by ball milling (molar ratio of 1:2) of mentioned powders and subsequent. After ball milling prepared mixtures were calcinatied at 700 °C in air atmosphere. The samples of formed catalysts were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The particle size distribution as well as the base strength using Hammett indicator was determined, too. CaO.ZnO catalysts were used in the methanolysis of sunflower oil, at 60 °C and 1 bar, using molar ratio of sunflower oil to methanol of 1:10 and with 2 wt% of catalyst based on oil weight. All catalysts exhibited good activity in the methanolysis of sunflower oil, with the yield of FAME above 90 % after 4 hours of reaction.
PB  - Elsevier
T2  - Procedia Engineering
T1  - Mechanochemically synthesized CaO ZnO catalyst for biodiesel production
VL  - 42
SP  - 1169
EP  - 1178
DO  - 10.1016/j.proeng.2012.07.509
ER  - 

@article{
author = "Kesić, Z. and Lukić, I. and Zdujić, M. and Liu, H. and Skala, Dejan",
year = "2012",
abstract = "The transesterification of triglycerides (vegetable oil) with methanol using CaO·ZnO mixed oxides catalyst were conducted to produce FAME (Fatty Acid Methyl Esters, i.e. biodiesel). Catalyst was synthesized by ball milling of CaO and ZnO powder mixture (using molar ratio of Ca and Zn of 1:2 and 1:4) with the addition of water, as well as solely by ball milling (molar ratio of 1:2) of mentioned powders and subsequent. After ball milling prepared mixtures were calcinatied at 700 °C in air atmosphere. The samples of formed catalysts were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The particle size distribution as well as the base strength using Hammett indicator was determined, too. CaO.ZnO catalysts were used in the methanolysis of sunflower oil, at 60 °C and 1 bar, using molar ratio of sunflower oil to methanol of 1:10 and with 2 wt% of catalyst based on oil weight. All catalysts exhibited good activity in the methanolysis of sunflower oil, with the yield of FAME above 90 % after 4 hours of reaction.",
publisher = "Elsevier",
journal = "Procedia Engineering",
title = "Mechanochemically synthesized CaO ZnO catalyst for biodiesel production",
volume = "42",
pages = "1169-1178",
doi = "10.1016/j.proeng.2012.07.509"
}

Kesić, Z., Lukić, I., Zdujić, M., Liu, H.,& Skala, D.. (2012). Mechanochemically synthesized CaO ZnO catalyst for biodiesel production. in Procedia Engineering
Elsevier., 42, 1169-1178.
https://doi.org/10.1016/j.proeng.2012.07.509

Kesić Z, Lukić I, Zdujić M, Liu H, Skala D. Mechanochemically synthesized CaO ZnO catalyst for biodiesel production. in Procedia Engineering. 2012;42:1169-1178.
doi:10.1016/j.proeng.2012.07.509 .

Kesić, Z., Lukić, I., Zdujić, M., Liu, H., Skala, Dejan, "Mechanochemically synthesized CaO ZnO catalyst for biodiesel production" in Procedia Engineering, 42 (2012):1169-1178,
https://doi.org/10.1016/j.proeng.2012.07.509 . .

TY  - JOUR
AU  - Dokic, Marko
AU  - Kesic, Zeljka
AU  - Krstić, Jugoslav
AU  - Jovanović, Dušan M.
AU  - Skala, Dejan
PY  - 2012
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/949
AB  - A difficulty of biodiesel synthesis based on alkaline catalysts obviously exists if free fatty acids (FFAs) content in vegetable oil is above 0.5 wt.%. In this study, the ferric sulfate supported on silica (Fe-2(SO4)(3)/SiO2) was synthesized, activated (at different temperature: 120-600 degrees C) and tested for heterogeneous esterification of FFA (oleic acid) present in sunflower oil (5 wt.%). The catalyst samples were characterized by BET, TG/DTG, XRD and FTIR analyses. Obtained results showed that catalyst activated at 500 degrees C for 2 h in air atmosphere gave the maximal conversion of oleic acid (similar to 97%). Repeated use of catalyst without additional catalyst treatment or re-activation indicated that catalyst posses desired stability and activity. A pseudo-homogeneous kinetic model was proposed with good agreement between calculated and experimental data.
PB  - Elsevier Sci Ltd, Oxford
T2  - Fuel
T1  - Decrease of free fatty acid content in vegetable oil using silica supported ferric sulfate catalyst
VL  - 97
SP  - 595
EP  - 602
DO  - 10.1016/j.fuel.2012.03.039
ER  - 

@article{
author = "Dokic, Marko and Kesic, Zeljka and Krstić, Jugoslav and Jovanović, Dušan M. and Skala, Dejan",
year = "2012",
abstract = "A difficulty of biodiesel synthesis based on alkaline catalysts obviously exists if free fatty acids (FFAs) content in vegetable oil is above 0.5 wt.%. In this study, the ferric sulfate supported on silica (Fe-2(SO4)(3)/SiO2) was synthesized, activated (at different temperature: 120-600 degrees C) and tested for heterogeneous esterification of FFA (oleic acid) present in sunflower oil (5 wt.%). The catalyst samples were characterized by BET, TG/DTG, XRD and FTIR analyses. Obtained results showed that catalyst activated at 500 degrees C for 2 h in air atmosphere gave the maximal conversion of oleic acid (similar to 97%). Repeated use of catalyst without additional catalyst treatment or re-activation indicated that catalyst posses desired stability and activity. A pseudo-homogeneous kinetic model was proposed with good agreement between calculated and experimental data.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Fuel",
title = "Decrease of free fatty acid content in vegetable oil using silica supported ferric sulfate catalyst",
volume = "97",
pages = "595-602",
doi = "10.1016/j.fuel.2012.03.039"
}

Dokic, M., Kesic, Z., Krstić, J., Jovanović, D. M.,& Skala, D.. (2012). Decrease of free fatty acid content in vegetable oil using silica supported ferric sulfate catalyst. in Fuel
Elsevier Sci Ltd, Oxford., 97, 595-602.
https://doi.org/10.1016/j.fuel.2012.03.039

Dokic M, Kesic Z, Krstić J, Jovanović DM, Skala D. Decrease of free fatty acid content in vegetable oil using silica supported ferric sulfate catalyst. in Fuel. 2012;97:595-602.
doi:10.1016/j.fuel.2012.03.039 .

Dokic, Marko, Kesic, Zeljka, Krstić, Jugoslav, Jovanović, Dušan M., Skala, Dejan, "Decrease of free fatty acid content in vegetable oil using silica supported ferric sulfate catalyst" in Fuel, 97 (2012):595-602,
https://doi.org/10.1016/j.fuel.2012.03.039 . .

TY  - JOUR
AU  - Lukić, Ivana
AU  - Krstić, Jugoslav
AU  - Glisic, Sandra
AU  - Jovanović, Dušan M.
AU  - Skala, Dejan
PY  - 2010
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/640
AB  - In this study, catalysts for fatty acid methyl esters (FAME or biodiesel) synthesis with K2CO3 as the active component on an alumina/silica support were synthesized using the sol-gel method, which was followed by drying the 'dense' wet gels with supercritical carbon dioxide to obtain the aerogels. The prepared catalysts were characterized by XRD analysis, FTIR spectroscopy and N2 physisorption at 77 K, and tested in the methanolysis of sunflower oil. The effects of reaction variables, such as reaction time, temperature and methanol to oil molar ratio, on the yield of FAME were investigated. The aerogel catalysts with K2CO3 as the active component on an alumina/silica support exhibited good activity in the methanolysis of sunflower oil. The leaching of potassium when the catalyst was in contact with pure methanol under the working conditions of methanolysis was also tested in this study, indicating that it occurred only at higher temperatures, while at lower ones, it was negligible.
AB  - U ovom radu katalizator za sintezu metil estara masnih kiselina (MEMK ili biodizel) sa K2CO3 kao aktivnom komponentom na alumosilikatnom nosaču sintetizovan je sol-gel metodom nakon čega je dobijeni gel sušen uz prisustvo natkritičnog ugljen dioksida da bi se dobio aerogel. Za karakterizaciju sintetizovanih katalizatora korišćene su metode XRD, FTIR i N2 fizisorpcija na 77 K i katalizatori su testirani u reakciji metanolize suncokretovog ulja. Katalizator je testiran u reakciji metanolize suncekrotovog ulja i sintezi MEMK. Ispitan je uticaj različitih parametara kao što su vreme, temperatura i molarni odnos metanol : ulje na prinos MEMK. Aerogel katalizator sa K2CO3 kao aktivnom komponentom na alumosilikatnom nosaču pokazao je dobru katalitičku aktivnost u reakciji metanolize suncokretovog ulja. Izluživanje kalijuma u kontaktu sa metanolom na radnim uslovima metanolize takođe je testirano u ovom radu, pokazujući da ono postoji na višim temperaturama, dok je na nižim zanemarljivo.
PB  - Serbian Chemical Society
T2  - Journal of the Serbian Chemical Society
T1  - Biodiesel synthesis using K2CO3/Al-O-Si aerogel catalysts
T1  - Sinteza biodizela katalizovana alumosilikatnim aerogelom sa K2Co3
VL  - 75
IS  - 6
SP  - 789
EP  - 801
DO  - 10.2298/JSC090707047L
ER  - 

@article{
author = "Lukić, Ivana and Krstić, Jugoslav and Glisic, Sandra and Jovanović, Dušan M. and Skala, Dejan",
year = "2010",
abstract = "In this study, catalysts for fatty acid methyl esters (FAME or biodiesel) synthesis with K2CO3 as the active component on an alumina/silica support were synthesized using the sol-gel method, which was followed by drying the 'dense' wet gels with supercritical carbon dioxide to obtain the aerogels. The prepared catalysts were characterized by XRD analysis, FTIR spectroscopy and N2 physisorption at 77 K, and tested in the methanolysis of sunflower oil. The effects of reaction variables, such as reaction time, temperature and methanol to oil molar ratio, on the yield of FAME were investigated. The aerogel catalysts with K2CO3 as the active component on an alumina/silica support exhibited good activity in the methanolysis of sunflower oil. The leaching of potassium when the catalyst was in contact with pure methanol under the working conditions of methanolysis was also tested in this study, indicating that it occurred only at higher temperatures, while at lower ones, it was negligible., U ovom radu katalizator za sintezu metil estara masnih kiselina (MEMK ili biodizel) sa K2CO3 kao aktivnom komponentom na alumosilikatnom nosaču sintetizovan je sol-gel metodom nakon čega je dobijeni gel sušen uz prisustvo natkritičnog ugljen dioksida da bi se dobio aerogel. Za karakterizaciju sintetizovanih katalizatora korišćene su metode XRD, FTIR i N2 fizisorpcija na 77 K i katalizatori su testirani u reakciji metanolize suncokretovog ulja. Katalizator je testiran u reakciji metanolize suncekrotovog ulja i sintezi MEMK. Ispitan je uticaj različitih parametara kao što su vreme, temperatura i molarni odnos metanol : ulje na prinos MEMK. Aerogel katalizator sa K2CO3 kao aktivnom komponentom na alumosilikatnom nosaču pokazao je dobru katalitičku aktivnost u reakciji metanolize suncokretovog ulja. Izluživanje kalijuma u kontaktu sa metanolom na radnim uslovima metanolize takođe je testirano u ovom radu, pokazujući da ono postoji na višim temperaturama, dok je na nižim zanemarljivo.",
publisher = "Serbian Chemical Society",
journal = "Journal of the Serbian Chemical Society",
title = "Biodiesel synthesis using K2CO3/Al-O-Si aerogel catalysts, Sinteza biodizela katalizovana alumosilikatnim aerogelom sa K2Co3",
volume = "75",
number = "6",
pages = "789-801",
doi = "10.2298/JSC090707047L"
}

Lukić, I., Krstić, J., Glisic, S., Jovanović, D. M.,& Skala, D.. (2010). Biodiesel synthesis using K2CO3/Al-O-Si aerogel catalysts. in Journal of the Serbian Chemical Society
Serbian Chemical Society., 75(6), 789-801.
https://doi.org/10.2298/JSC090707047L

Lukić I, Krstić J, Glisic S, Jovanović DM, Skala D. Biodiesel synthesis using K2CO3/Al-O-Si aerogel catalysts. in Journal of the Serbian Chemical Society. 2010;75(6):789-801.
doi:10.2298/JSC090707047L .

Lukić, Ivana, Krstić, Jugoslav, Glisic, Sandra, Jovanović, Dušan M., Skala, Dejan, "Biodiesel synthesis using K2CO3/Al-O-Si aerogel catalysts" in Journal of the Serbian Chemical Society, 75, no. 6 (2010):789-801,
https://doi.org/10.2298/JSC090707047L . .

TY  - JOUR
AU  - Lukić, I.
AU  - Krstić, Jugoslav
AU  - Jovanović, D.
AU  - Skala, Dejan
PY  - 2009
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/605
AB  - The new type of catalyst for fatty acid methyl esters (FAME or biodiesel) synthesis with K2CO3 as active component on alumina/silica support was synthesized using sol-gel method. Corresponding catalyst (xerogel) was prepared by 12 h drying the wet gel in air at 300 °C, 600 °C or 1000 °C at atmospheric pressure. The catalysts activity in the methanolysis of sunflower oil was compared to the activity of the pure K2CO3. The effects of various reaction variables on the yield of FAME were investigated. It was found that the temperature of 120 °C and methanol to oil molar ratio of 15:1, are optimal conditions for FAME synthesis with synthesized catalyst. Repeated use of same amount of catalyst indicated that effect of potassium leaching obviously existed leading to decrease of catalyst activity.
PB  - Elsevier Sci Ltd, Oxford
T2  - Bioresource Technology
T1  - Alumina/silica supported K2CO3 as a catalyst for biodiesel synthesis from sunflower oil
VL  - 100
IS  - 20
SP  - 4690
EP  - 4696
DO  - 10.1016/j.biortech.2009.04.057
ER  - 

@article{
author = "Lukić, I. and Krstić, Jugoslav and Jovanović, D. and Skala, Dejan",
year = "2009",
abstract = "The new type of catalyst for fatty acid methyl esters (FAME or biodiesel) synthesis with K2CO3 as active component on alumina/silica support was synthesized using sol-gel method. Corresponding catalyst (xerogel) was prepared by 12 h drying the wet gel in air at 300 °C, 600 °C or 1000 °C at atmospheric pressure. The catalysts activity in the methanolysis of sunflower oil was compared to the activity of the pure K2CO3. The effects of various reaction variables on the yield of FAME were investigated. It was found that the temperature of 120 °C and methanol to oil molar ratio of 15:1, are optimal conditions for FAME synthesis with synthesized catalyst. Repeated use of same amount of catalyst indicated that effect of potassium leaching obviously existed leading to decrease of catalyst activity.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Bioresource Technology",
title = "Alumina/silica supported K2CO3 as a catalyst for biodiesel synthesis from sunflower oil",
volume = "100",
number = "20",
pages = "4690-4696",
doi = "10.1016/j.biortech.2009.04.057"
}

Lukić, I., Krstić, J., Jovanović, D.,& Skala, D.. (2009). Alumina/silica supported K2CO3 as a catalyst for biodiesel synthesis from sunflower oil. in Bioresource Technology
Elsevier Sci Ltd, Oxford., 100(20), 4690-4696.
https://doi.org/10.1016/j.biortech.2009.04.057

Lukić I, Krstić J, Jovanović D, Skala D. Alumina/silica supported K2CO3 as a catalyst for biodiesel synthesis from sunflower oil. in Bioresource Technology. 2009;100(20):4690-4696.
doi:10.1016/j.biortech.2009.04.057 .

Lukić, I., Krstić, Jugoslav, Jovanović, D., Skala, Dejan, "Alumina/silica supported K2CO3 as a catalyst for biodiesel synthesis from sunflower oil" in Bioresource Technology, 100, no. 20 (2009):4690-4696,
https://doi.org/10.1016/j.biortech.2009.04.057 . .

TY  - JOUR
AU  - Skala, Dejan
AU  - Orlović, Aleksandar
AU  - Marković, Bojana
AU  - Terlecki-Baričević, Ana V.
AU  - Jovanović, D.
PY  - 2002
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/83
AB  - The performed investigations were directed toward the analysis of the performance and activity of the fresh and regenerated Cyanamid HDS 20C catalyst in a laboratory batch reactor (2 dm3) for the HDS of the diesel fraction (light gas oil, LGO). Testing of the regenerated catalyst was performed with light gas oil (LGO) of different characteristics. The determined values of the reaction rate constant were compared to some published data in the literature for the HDS of specific sulfur compounds as well as the values of the activation energy. The rates of deactivation of the fresh and regenerated catalyst actually existed compared to some other results recently published in the literature. However, such an observed differences were not sufficient to derive a relation which could be used for the determination of the rate of catalyst deactivation.
PB  - Association of the Chemical Engineers of Serbia
T2  - Chemical Industry and Chemical Engineering Quarterly / CICEQ
T1  - Hydrodesulfurization of light gas oil - kinetic determination in a batch reactor [Hidrodesulfurizacija lakog gasnog ulja - ispitivanje kinetike HDS u šaržnom reaktoru]
VL  - 8
IS  - 4
SP  - 529
EP  - 532
UR  - https://hdl.handle.net/21.15107/rcub_cer_83
ER  - 

@article{
author = "Skala, Dejan and Orlović, Aleksandar and Marković, Bojana and Terlecki-Baričević, Ana V. and Jovanović, D.",
year = "2002",
abstract = "The performed investigations were directed toward the analysis of the performance and activity of the fresh and regenerated Cyanamid HDS 20C catalyst in a laboratory batch reactor (2 dm3) for the HDS of the diesel fraction (light gas oil, LGO). Testing of the regenerated catalyst was performed with light gas oil (LGO) of different characteristics. The determined values of the reaction rate constant were compared to some published data in the literature for the HDS of specific sulfur compounds as well as the values of the activation energy. The rates of deactivation of the fresh and regenerated catalyst actually existed compared to some other results recently published in the literature. However, such an observed differences were not sufficient to derive a relation which could be used for the determination of the rate of catalyst deactivation.",
publisher = "Association of the Chemical Engineers of Serbia",
journal = "Chemical Industry and Chemical Engineering Quarterly / CICEQ",
title = "Hydrodesulfurization of light gas oil - kinetic determination in a batch reactor [Hidrodesulfurizacija lakog gasnog ulja - ispitivanje kinetike HDS u šaržnom reaktoru]",
volume = "8",
number = "4",
pages = "529-532",
url = "https://hdl.handle.net/21.15107/rcub_cer_83"
}

Skala, D., Orlović, A., Marković, B., Terlecki-Baričević, A. V.,& Jovanović, D.. (2002). Hydrodesulfurization of light gas oil - kinetic determination in a batch reactor [Hidrodesulfurizacija lakog gasnog ulja - ispitivanje kinetike HDS u šaržnom reaktoru]. in Chemical Industry and Chemical Engineering Quarterly / CICEQ
Association of the Chemical Engineers of Serbia., 8(4), 529-532.
https://hdl.handle.net/21.15107/rcub_cer_83

Skala D, Orlović A, Marković B, Terlecki-Baričević AV, Jovanović D. Hydrodesulfurization of light gas oil - kinetic determination in a batch reactor [Hidrodesulfurizacija lakog gasnog ulja - ispitivanje kinetike HDS u šaržnom reaktoru]. in Chemical Industry and Chemical Engineering Quarterly / CICEQ. 2002;8(4):529-532.
https://hdl.handle.net/21.15107/rcub_cer_83 .

Skala, Dejan, Orlović, Aleksandar, Marković, Bojana, Terlecki-Baričević, Ana V., Jovanović, D., "Hydrodesulfurization of light gas oil - kinetic determination in a batch reactor [Hidrodesulfurizacija lakog gasnog ulja - ispitivanje kinetike HDS u šaržnom reaktoru]" in Chemical Industry and Chemical Engineering Quarterly / CICEQ, 8, no. 4 (2002):529-532,
https://hdl.handle.net/21.15107/rcub_cer_83 .