TY  - CONF
AU  - Lukić, Ivana
AU  - Kesić, Željka
AU  - Zdujić, Miodrag
AU  - Skala, Dejan
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6934
AB  - Biodiesel, a mixture of fatty acid methyl esters (FAME), is an excellent non-toxic, and biodegradable substitute for mineral diesel fuels produced from crude oil. It is made from renewable sources by transesterification of triglycerides with methanol, or by a reaction usually defined as methanolysis. Usage of low-quality feedstock, such as waste cooking oil (WCO), is challenging due to the undesirable side reactions as a result of the presence of free fatty acids (FFA), and water, thus a pretreatment stage before subjecting it to the transesterification process is usually required. In the present study, a two-step approach based on an adsorptive pretreatment with quicklime in order to remove FFA from WCO, followed by methanolysis using CaO∙ZnO as a heterogeneous catalyst was proposed. The first step was analyzed with the goal to define the optimal temperature of adsorption, the adsorbent particle size, calcination procedure, as well as the necessary amount of quicklime used. The analysis of adsorption kinetics was performed using pseudo-first and pseudo-second order kinetic models, and the efficiency of quicklime in the FFA removal from the WCO was also determined. The results showed that FFA from WCO could be successfully removed using quicklime as adsorbent at 30 °C for 1 h, with a removal efficiency of 72% and an adsorption capacity of 910 mg/g. The amount of Ca2+ ion present in the oil after the pretreatment was determined to be 12.64 mg/kg, showing that a very small amount of calcium from CaO was dissolved in treated WCO. The FTIR analysis of quicklime after the adsorption of FFA confirmed the interaction of the carboxyl group in FFA with the active site of the adsorbent. Adsorptive pretreatment had a positive effect on the rate of transesterification reaction with CaO∙ZnO as a catalyst, enabling the achievement of over 96% of FAME yield in only 15 min at 60 °C. The present study showed that quicklime, being cheap, available, and efficient, has considerable potential for the removal of FFA from the WCO. Besides, both the adsorption and the heterogeneously catalyzed methanolysis are environmentally and economically acceptable processes.
PB  - Valladolid : The lnstitute of Bioeconomy of University of Valladolid
C3  - Book of abstracts / 2nd Greenering International Conference, 21–23th March 2023, Valladolid, Spain
T1  - Adsorptive pretreatment of waste cooking oil using quicklime for two-step biodiesel production
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6934
ER  - 

@conference{
author = "Lukić, Ivana and Kesić, Željka and Zdujić, Miodrag and Skala, Dejan",
year = "2023",
abstract = "Biodiesel, a mixture of fatty acid methyl esters (FAME), is an excellent non-toxic, and biodegradable substitute for mineral diesel fuels produced from crude oil. It is made from renewable sources by transesterification of triglycerides with methanol, or by a reaction usually defined as methanolysis. Usage of low-quality feedstock, such as waste cooking oil (WCO), is challenging due to the undesirable side reactions as a result of the presence of free fatty acids (FFA), and water, thus a pretreatment stage before subjecting it to the transesterification process is usually required. In the present study, a two-step approach based on an adsorptive pretreatment with quicklime in order to remove FFA from WCO, followed by methanolysis using CaO∙ZnO as a heterogeneous catalyst was proposed. The first step was analyzed with the goal to define the optimal temperature of adsorption, the adsorbent particle size, calcination procedure, as well as the necessary amount of quicklime used. The analysis of adsorption kinetics was performed using pseudo-first and pseudo-second order kinetic models, and the efficiency of quicklime in the FFA removal from the WCO was also determined. The results showed that FFA from WCO could be successfully removed using quicklime as adsorbent at 30 °C for 1 h, with a removal efficiency of 72% and an adsorption capacity of 910 mg/g. The amount of Ca2+ ion present in the oil after the pretreatment was determined to be 12.64 mg/kg, showing that a very small amount of calcium from CaO was dissolved in treated WCO. The FTIR analysis of quicklime after the adsorption of FFA confirmed the interaction of the carboxyl group in FFA with the active site of the adsorbent. Adsorptive pretreatment had a positive effect on the rate of transesterification reaction with CaO∙ZnO as a catalyst, enabling the achievement of over 96% of FAME yield in only 15 min at 60 °C. The present study showed that quicklime, being cheap, available, and efficient, has considerable potential for the removal of FFA from the WCO. Besides, both the adsorption and the heterogeneously catalyzed methanolysis are environmentally and economically acceptable processes.",
publisher = "Valladolid : The lnstitute of Bioeconomy of University of Valladolid",
journal = "Book of abstracts / 2nd Greenering International Conference, 21–23th March 2023, Valladolid, Spain",
title = "Adsorptive pretreatment of waste cooking oil using quicklime for two-step biodiesel production",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6934"
}

Lukić, I., Kesić, Ž., Zdujić, M.,& Skala, D.. (2023). Adsorptive pretreatment of waste cooking oil using quicklime for two-step biodiesel production. in Book of abstracts / 2nd Greenering International Conference, 21–23th March 2023, Valladolid, Spain
Valladolid : The lnstitute of Bioeconomy of University of Valladolid..
https://hdl.handle.net/21.15107/rcub_technorep_6934

Lukić I, Kesić Ž, Zdujić M, Skala D. Adsorptive pretreatment of waste cooking oil using quicklime for two-step biodiesel production. in Book of abstracts / 2nd Greenering International Conference, 21–23th March 2023, Valladolid, Spain. 2023;.
https://hdl.handle.net/21.15107/rcub_technorep_6934 .

Lukić, Ivana, Kesić, Željka, Zdujić, Miodrag, Skala, Dejan, "Adsorptive pretreatment of waste cooking oil using quicklime for two-step biodiesel production" in Book of abstracts / 2nd Greenering International Conference, 21–23th March 2023, Valladolid, Spain (2023),
https://hdl.handle.net/21.15107/rcub_technorep_6934 .

TY  - JOUR
AU  - Lukić, Ivana
AU  - Kesić, Željka
AU  - Zdujić, Miodrag
AU  - Skala, Dejan
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6569
AB  - Synthesis of biodiesel from various plant oils is realized by the transesterification of triglycerides with methanol or by a reaction usually defined as methanolysis. The usage of low-quality oils, such as waste cooking oil (WCO), is followed by undesirable side reactions as a result of the increased content of free fatty acids (FFA), and water. The presence of FFA in WCO usually requires a pretreatment stage before subjecting it to methanolysis. In the present work, heterogeneously catalyzed methanolysis of WCO with and without pretreatment was investigated. Removal of FFA from WCO was conducted by using only quicklime or with the addition of a small amount of methanol (FFA to methanol = 1:3 molar ratio). The obtained results showed that pretreatment of WCO with quicklime at 30 °C after 1 h reduces the FFA content by 72 %, while the adsorption capacity was determined to be 910 mg g-1. The adsorptive pretreatment, as a simple operation, using low-cost quicklime under mild conditions, had a positive effect on the transesterification rate with CaO∙ZnO as a catalyst, enabling the achievement of over 96 % of biodiesel yield in only 15 min, compared to 1 h without the pretreatment. Furthermore, pretreated WCO allows an increase in repeated catalyst use and overall savings in the necessary amount of catalyst. The present study showed that quicklime is an economic, environmental-friendly, and sustainable material for FFA removal from WCO.
PB  - Association of the Chemical Engineers of Serbia
T2  - Hemijska industrija
T1  - Adsorptive pretreatment of waste cooking oil using quicklime for fatty acid methyl esters synthesis
EP  - 84
IS  - 1
SP  - 69
VL  - 77
DO  - 10.2298/HEMIND220628005L
ER  - 

@article{
author = "Lukić, Ivana and Kesić, Željka and Zdujić, Miodrag and Skala, Dejan",
year = "2023",
abstract = "Synthesis of biodiesel from various plant oils is realized by the transesterification of triglycerides with methanol or by a reaction usually defined as methanolysis. The usage of low-quality oils, such as waste cooking oil (WCO), is followed by undesirable side reactions as a result of the increased content of free fatty acids (FFA), and water. The presence of FFA in WCO usually requires a pretreatment stage before subjecting it to methanolysis. In the present work, heterogeneously catalyzed methanolysis of WCO with and without pretreatment was investigated. Removal of FFA from WCO was conducted by using only quicklime or with the addition of a small amount of methanol (FFA to methanol = 1:3 molar ratio). The obtained results showed that pretreatment of WCO with quicklime at 30 °C after 1 h reduces the FFA content by 72 %, while the adsorption capacity was determined to be 910 mg g-1. The adsorptive pretreatment, as a simple operation, using low-cost quicklime under mild conditions, had a positive effect on the transesterification rate with CaO∙ZnO as a catalyst, enabling the achievement of over 96 % of biodiesel yield in only 15 min, compared to 1 h without the pretreatment. Furthermore, pretreated WCO allows an increase in repeated catalyst use and overall savings in the necessary amount of catalyst. The present study showed that quicklime is an economic, environmental-friendly, and sustainable material for FFA removal from WCO.",
publisher = "Association of the Chemical Engineers of Serbia",
journal = "Hemijska industrija",
title = "Adsorptive pretreatment of waste cooking oil using quicklime for fatty acid methyl esters synthesis",
pages = "84-69",
number = "1",
volume = "77",
doi = "10.2298/HEMIND220628005L"
}

Lukić, I., Kesić, Ž., Zdujić, M.,& Skala, D.. (2023). Adsorptive pretreatment of waste cooking oil using quicklime for fatty acid methyl esters synthesis. in Hemijska industrija
Association of the Chemical Engineers of Serbia., 77(1), 69-84.
https://doi.org/10.2298/HEMIND220628005L

Lukić I, Kesić Ž, Zdujić M, Skala D. Adsorptive pretreatment of waste cooking oil using quicklime for fatty acid methyl esters synthesis. in Hemijska industrija. 2023;77(1):69-84.
doi:10.2298/HEMIND220628005L .

Lukić, Ivana, Kesić, Željka, Zdujić, Miodrag, Skala, Dejan, "Adsorptive pretreatment of waste cooking oil using quicklime for fatty acid methyl esters synthesis" in Hemijska industrija, 77, no. 1 (2023):69-84,
https://doi.org/10.2298/HEMIND220628005L . .

TY  - JOUR
AU  - Zdujić, Miodrag
AU  - Lukić, Ivana
AU  - Kesić, Željka
AU  - Janković-Častvan, Ivona
AU  - Marković, Smilja
AU  - Jovalekić, Čedomir
AU  - Skala, Dejan
PY  - 2019
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4261
AB  - The powder mixtures of calcium oxide (CaO) and silica gel (SiO2) in molar ratios of 1:1, 1.5:1, 2:1 and 3:1 were mechanochemically treated with the addition of water, and were subsequently calcined with a goal of synthesizing CaSiO3, Ca3Si2O7, Ca2SiO4 compounds and CaO/Ca2SiO4 two-phase mixture. The prepared materials were characterized by XRD, FTIR, SEM/EDS, particle size laser diffraction (PSLD), UV-vis diffuse reflectance spectroscopy (DRS), N-2 adsorption/desorption isotherms, Hammett indicator for basic strength and volumetric analysis for free CaO content. The catalytic activity of calcium silicates with different Ca/Si ratios was tested in the transesterification of triacylglycerols (sunflower oil) with methanol. Samples obtained with initial composition 2CaO center dot SiO2 and 3CaO center dot SiO2 calcined at 700 degrees C, and 3CaO center dot SiO2 calcined at 900 degrees C had high catalytic activity, resulting with triacylglycerols conversion and fatty acids methyl ester formation (FAME or biodiesel) above 96%. The activity of these samples can be attributed to the existence of free CaO defined by CaO/Ca2SiO4 complex mixture. The effect of different amount of catalyst used for transesterification (0.2-2 wt%) was analyzed using the most active catalyst i.e. 3CaO center dot SiO2 calcined at 700 degrees C as well as possibility of its reuse for biodiesel synthesis. It was also found that CaSiO3, Ca3Si2O7 and Ca2SiO4, phases did not possess catalytic activity.
PB  - Elsevier Science Bv, Amsterdam
T2  - Advanced Powder Technology
T1  - Synthesis of CaO-SiO2 compounds and their testing as heterogeneous catalysts for transesterification of sunflower oil
EP  - 1150
IS  - 6
SP  - 1141
VL  - 30
DO  - 10.1016/j.apt.2019.03.009
ER  - 

@article{
author = "Zdujić, Miodrag and Lukić, Ivana and Kesić, Željka and Janković-Častvan, Ivona and Marković, Smilja and Jovalekić, Čedomir and Skala, Dejan",
year = "2019",
abstract = "The powder mixtures of calcium oxide (CaO) and silica gel (SiO2) in molar ratios of 1:1, 1.5:1, 2:1 and 3:1 were mechanochemically treated with the addition of water, and were subsequently calcined with a goal of synthesizing CaSiO3, Ca3Si2O7, Ca2SiO4 compounds and CaO/Ca2SiO4 two-phase mixture. The prepared materials were characterized by XRD, FTIR, SEM/EDS, particle size laser diffraction (PSLD), UV-vis diffuse reflectance spectroscopy (DRS), N-2 adsorption/desorption isotherms, Hammett indicator for basic strength and volumetric analysis for free CaO content. The catalytic activity of calcium silicates with different Ca/Si ratios was tested in the transesterification of triacylglycerols (sunflower oil) with methanol. Samples obtained with initial composition 2CaO center dot SiO2 and 3CaO center dot SiO2 calcined at 700 degrees C, and 3CaO center dot SiO2 calcined at 900 degrees C had high catalytic activity, resulting with triacylglycerols conversion and fatty acids methyl ester formation (FAME or biodiesel) above 96%. The activity of these samples can be attributed to the existence of free CaO defined by CaO/Ca2SiO4 complex mixture. The effect of different amount of catalyst used for transesterification (0.2-2 wt%) was analyzed using the most active catalyst i.e. 3CaO center dot SiO2 calcined at 700 degrees C as well as possibility of its reuse for biodiesel synthesis. It was also found that CaSiO3, Ca3Si2O7 and Ca2SiO4, phases did not possess catalytic activity.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Advanced Powder Technology",
title = "Synthesis of CaO-SiO2 compounds and their testing as heterogeneous catalysts for transesterification of sunflower oil",
pages = "1150-1141",
number = "6",
volume = "30",
doi = "10.1016/j.apt.2019.03.009"
}

Zdujić, M., Lukić, I., Kesić, Ž., Janković-Častvan, I., Marković, S., Jovalekić, Č.,& Skala, D.. (2019). Synthesis of CaO-SiO2 compounds and their testing as heterogeneous catalysts for transesterification of sunflower oil. in Advanced Powder Technology
Elsevier Science Bv, Amsterdam., 30(6), 1141-1150.
https://doi.org/10.1016/j.apt.2019.03.009

Zdujić M, Lukić I, Kesić Ž, Janković-Častvan I, Marković S, Jovalekić Č, Skala D. Synthesis of CaO-SiO2 compounds and their testing as heterogeneous catalysts for transesterification of sunflower oil. in Advanced Powder Technology. 2019;30(6):1141-1150.
doi:10.1016/j.apt.2019.03.009 .

Zdujić, Miodrag, Lukić, Ivana, Kesić, Željka, Janković-Častvan, Ivona, Marković, Smilja, Jovalekić, Čedomir, Skala, Dejan, "Synthesis of CaO-SiO2 compounds and their testing as heterogeneous catalysts for transesterification of sunflower oil" in Advanced Powder Technology, 30, no. 6 (2019):1141-1150,
https://doi.org/10.1016/j.apt.2019.03.009 . .

TY  - CHAP
AU  - Lukić, Ivana
AU  - Kesić, Željka
AU  - Zdujić, Miodrag
AU  - Skala, Dejan
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3160
AB  - Increased environmental concern and awareness of limited reserves of fossil fuels gave a great importance to alternative and renewable energy sources over the past couple decades. An excellent substitute for mineral diesel fuels is biodiesel, a mixture of fatty acid methyl esters (FAME), made by alcoholysis of different triacylglycerols (TAG) from various renewable sources (vegetable oils or animal fats) in the presence of a homogeneous or heterogeneous catalyst. Drawbacks of homogeneously catalyzed alcoholysis, to-day the most commonly used commercial biodiesel production process, have shifted the research focus on technologies based on utilization of solid catalyst. Heterogeneously catalyzed alcoholysis is more environmentally friendly, offers simplified production and improved process efficiency, allowing the possibility of catalyst’s regeneration, too. This technology of biodiesel synthesis is also the base for the continuous process development. Although great attention has been paid to the development of a catalyst that will have good activity and stability, followed by cheap method of synthesis, this task is still a challenge and needs further intensive research. Solid base catalysts have been characterized by high activity under mild reaction conditions and short reaction times, however, due to their sensitivity to the presence of impurities in the oil, primary the presence of free fatty acids (FFA) and water, they were not suitable, according to results of many investigations, for transesterification of lower-cost feedstock, such as non-edible plant oils and the waste cooking oils. For these feedstocks heterogeneous biodiesel synthesis should be performed applying solid acid catalyst. Despite the generally lower activity compared to solid base catalysts and higher reaction temperatures required for transesterification of oils into biodiesel, the main advantage of solid acids is their ability to simultaneously carry out esterification of FFA and transesterification of TAG. It is the main reason why application of solid acids for biodiesel production became a growing field of research during the last few years. In the present chapter, a comprehensive review of different solid acids used for biodiesel synthesis is presented. The method of catalyst preparation, type of precursor and employed calcination temperature greatly affect the acid catalyst activity and its final properties. The concentration of catalytic sites along with other characteristics, like surface area and catalyst porosity, are of great importance for catalytic activity of solid acids. The solid acids synthesis procedures and main catalyst’s characteristics are also analyzed in details, as well as the activity of solid acid catalysts in transesterification of different feedstock, with the emphasis on the lower-quality materials with high FFA content. One of the problems associated with heterogeneous catalysts is their deactivation with time due to poisoning, sintering or leaching of the active components, thus the attention in this review is also devoted to this issue. Furthermore, the transesterification process kinetics, being fundamental to reactor design and optimization of operational conditions in order to achieve maximum yield and lower cost of the process, is discussed.
T2  - Heterogeneous Catalysts: Design, Applications and Research Insights
T1  - Solid acids as catalysts for biodiesel synthesis
EP  - 136
SP  - 21
UR  - https://hdl.handle.net/21.15107/rcub_technorep_3160
ER  - 

@inbook{
author = "Lukić, Ivana and Kesić, Željka and Zdujić, Miodrag and Skala, Dejan",
year = "2016",
abstract = "Increased environmental concern and awareness of limited reserves of fossil fuels gave a great importance to alternative and renewable energy sources over the past couple decades. An excellent substitute for mineral diesel fuels is biodiesel, a mixture of fatty acid methyl esters (FAME), made by alcoholysis of different triacylglycerols (TAG) from various renewable sources (vegetable oils or animal fats) in the presence of a homogeneous or heterogeneous catalyst. Drawbacks of homogeneously catalyzed alcoholysis, to-day the most commonly used commercial biodiesel production process, have shifted the research focus on technologies based on utilization of solid catalyst. Heterogeneously catalyzed alcoholysis is more environmentally friendly, offers simplified production and improved process efficiency, allowing the possibility of catalyst’s regeneration, too. This technology of biodiesel synthesis is also the base for the continuous process development. Although great attention has been paid to the development of a catalyst that will have good activity and stability, followed by cheap method of synthesis, this task is still a challenge and needs further intensive research. Solid base catalysts have been characterized by high activity under mild reaction conditions and short reaction times, however, due to their sensitivity to the presence of impurities in the oil, primary the presence of free fatty acids (FFA) and water, they were not suitable, according to results of many investigations, for transesterification of lower-cost feedstock, such as non-edible plant oils and the waste cooking oils. For these feedstocks heterogeneous biodiesel synthesis should be performed applying solid acid catalyst. Despite the generally lower activity compared to solid base catalysts and higher reaction temperatures required for transesterification of oils into biodiesel, the main advantage of solid acids is their ability to simultaneously carry out esterification of FFA and transesterification of TAG. It is the main reason why application of solid acids for biodiesel production became a growing field of research during the last few years. In the present chapter, a comprehensive review of different solid acids used for biodiesel synthesis is presented. The method of catalyst preparation, type of precursor and employed calcination temperature greatly affect the acid catalyst activity and its final properties. The concentration of catalytic sites along with other characteristics, like surface area and catalyst porosity, are of great importance for catalytic activity of solid acids. The solid acids synthesis procedures and main catalyst’s characteristics are also analyzed in details, as well as the activity of solid acid catalysts in transesterification of different feedstock, with the emphasis on the lower-quality materials with high FFA content. One of the problems associated with heterogeneous catalysts is their deactivation with time due to poisoning, sintering or leaching of the active components, thus the attention in this review is also devoted to this issue. Furthermore, the transesterification process kinetics, being fundamental to reactor design and optimization of operational conditions in order to achieve maximum yield and lower cost of the process, is discussed.",
journal = "Heterogeneous Catalysts: Design, Applications and Research Insights",
booktitle = "Solid acids as catalysts for biodiesel synthesis",
pages = "136-21",
url = "https://hdl.handle.net/21.15107/rcub_technorep_3160"
}

Lukić, I., Kesić, Ž., Zdujić, M.,& Skala, D.. (2016). Solid acids as catalysts for biodiesel synthesis. in Heterogeneous Catalysts: Design, Applications and Research Insights, 21-136.
https://hdl.handle.net/21.15107/rcub_technorep_3160

Lukić I, Kesić Ž, Zdujić M, Skala D. Solid acids as catalysts for biodiesel synthesis. in Heterogeneous Catalysts: Design, Applications and Research Insights. 2016;:21-136.
https://hdl.handle.net/21.15107/rcub_technorep_3160 .

Lukić, Ivana, Kesić, Željka, Zdujić, Miodrag, Skala, Dejan, "Solid acids as catalysts for biodiesel synthesis" in Heterogeneous Catalysts: Design, Applications and Research Insights (2016):21-136,
https://hdl.handle.net/21.15107/rcub_technorep_3160 .

TY  - CHAP
AU  - Lukić, Ivana
AU  - Kesić, Željka
AU  - Zdujić, Miodrag
AU  - Skala, Dejan
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3173
AB  - Limited reserves of fossil fuels as well as the growing concern for the environment, has led to a worldwide search for renewable energy sources, among which biodiesel, a mixture of fatty acid methyl esters (FAME), is one of the most perspective alternative fuels since it is a non-toxic and can be produced from different renewable sources through simple cost-effective alcoholysis, while being compatible with existing infrastructures. Vegetable oils, as renewable in nature and environmentally friendly, with a possibility to be produced on a large scale, represent a promising feedstock for biodiesel production. In this chapter, a comprehensive review of different vegetable oils as a feedstock for biodiesel synthesis is reported, including edible and non-edible oils, as well as waste vegetable oils. Selection of feedstock for biodiesel production mainly depends on the specific conditions and circumstances in some region (climate, presence of certain crops, the economic development of a country, etc.). Various fatty acid compositions of triacylglycerols directly determine the quality and fulfillment of the standards of biodiesel. One of the crucial points which determine technology route for biodiesel synthesis is content of free fatty acids (FFA) which might be present in vegetable oils, as well as the presence of water and other compounds. Also, many analysis performed in the past have shown that the production cost of biodiesel is mainly determined by the price of used feedstock, which represents 70-80% of total production costs of biodiesel. Currently more than 95% of feedstock comes from edible oils since they are easily accessible, consists mainly of triacylglycerols, whereby the properties of biodiesel produced from these oils are suitable to be used as diesel fuel substitute. Most commonly used edible oils for biodiesel production are rapeseed, soybean, sunflower and palm. However, for economic and social reasons, in recent years research and development of biodiesel production has focused on other sources of triacylglycerols, in order to replace edible oils by lower-cost non-edible plant oils and the waste cooking oils, feedstocks that are unsuitable for human consumption. Properties of different oils and biodiesel obtained from them as well as the technologies suitable for biodiesel synthesis are compared in this chapter. The wellknown fact is that the conventional and to-day widely applied homogeneous method of biodiesel synthesis is sensitive to the presence of impurities in the oil, primarily the presence of FFA and water. Furthermore, biodiesel synthesis is followed by creation of large amount of wastewater produced during neutralization of catalyst and purification of final product. The drawbacks of a homogeneous process can be avoided by applying technologies based on utilization of heterogeneous catalyst or by application of the noncatalytic supercritical process of biodiesel synthesis. These technologies for biodiesel production were also analyzed and compared.
T2  - Vegetable Oil: Properties, Uses and Benefits
T1  - Vegetable oil as a feedstock for biodiesel synthesis
EP  - 128
SP  - 83
UR  - https://hdl.handle.net/21.15107/rcub_technorep_3173
ER  - 

@inbook{
author = "Lukić, Ivana and Kesić, Željka and Zdujić, Miodrag and Skala, Dejan",
year = "2016",
abstract = "Limited reserves of fossil fuels as well as the growing concern for the environment, has led to a worldwide search for renewable energy sources, among which biodiesel, a mixture of fatty acid methyl esters (FAME), is one of the most perspective alternative fuels since it is a non-toxic and can be produced from different renewable sources through simple cost-effective alcoholysis, while being compatible with existing infrastructures. Vegetable oils, as renewable in nature and environmentally friendly, with a possibility to be produced on a large scale, represent a promising feedstock for biodiesel production. In this chapter, a comprehensive review of different vegetable oils as a feedstock for biodiesel synthesis is reported, including edible and non-edible oils, as well as waste vegetable oils. Selection of feedstock for biodiesel production mainly depends on the specific conditions and circumstances in some region (climate, presence of certain crops, the economic development of a country, etc.). Various fatty acid compositions of triacylglycerols directly determine the quality and fulfillment of the standards of biodiesel. One of the crucial points which determine technology route for biodiesel synthesis is content of free fatty acids (FFA) which might be present in vegetable oils, as well as the presence of water and other compounds. Also, many analysis performed in the past have shown that the production cost of biodiesel is mainly determined by the price of used feedstock, which represents 70-80% of total production costs of biodiesel. Currently more than 95% of feedstock comes from edible oils since they are easily accessible, consists mainly of triacylglycerols, whereby the properties of biodiesel produced from these oils are suitable to be used as diesel fuel substitute. Most commonly used edible oils for biodiesel production are rapeseed, soybean, sunflower and palm. However, for economic and social reasons, in recent years research and development of biodiesel production has focused on other sources of triacylglycerols, in order to replace edible oils by lower-cost non-edible plant oils and the waste cooking oils, feedstocks that are unsuitable for human consumption. Properties of different oils and biodiesel obtained from them as well as the technologies suitable for biodiesel synthesis are compared in this chapter. The wellknown fact is that the conventional and to-day widely applied homogeneous method of biodiesel synthesis is sensitive to the presence of impurities in the oil, primarily the presence of FFA and water. Furthermore, biodiesel synthesis is followed by creation of large amount of wastewater produced during neutralization of catalyst and purification of final product. The drawbacks of a homogeneous process can be avoided by applying technologies based on utilization of heterogeneous catalyst or by application of the noncatalytic supercritical process of biodiesel synthesis. These technologies for biodiesel production were also analyzed and compared.",
journal = "Vegetable Oil: Properties, Uses and Benefits",
booktitle = "Vegetable oil as a feedstock for biodiesel synthesis",
pages = "128-83",
url = "https://hdl.handle.net/21.15107/rcub_technorep_3173"
}

Lukić, I., Kesić, Ž., Zdujić, M.,& Skala, D.. (2016). Vegetable oil as a feedstock for biodiesel synthesis. in Vegetable Oil: Properties, Uses and Benefits, 83-128.
https://hdl.handle.net/21.15107/rcub_technorep_3173

Lukić I, Kesić Ž, Zdujić M, Skala D. Vegetable oil as a feedstock for biodiesel synthesis. in Vegetable Oil: Properties, Uses and Benefits. 2016;:83-128.
https://hdl.handle.net/21.15107/rcub_technorep_3173 .

Lukić, Ivana, Kesić, Željka, Zdujić, Miodrag, Skala, Dejan, "Vegetable oil as a feedstock for biodiesel synthesis" in Vegetable Oil: Properties, Uses and Benefits (2016):83-128,
https://hdl.handle.net/21.15107/rcub_technorep_3173 .

TY  - JOUR
AU  - Kesić, Željka
AU  - Lukić, Ivana
AU  - Zdujić, Miodrag
AU  - Mojović, Ljiljana
AU  - Skala, Dejan
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3380
AB  - Vegetable oils are mainly esters of fatty acids and glycerol, which can be converted to fatty acid methyl esters (FAME), also known as biodiesel, by the transesterification reaction with methanol. In order to attain environmental benignity, much attention has been focused in the last decades on utilizing heterogeneous catalysts for biodiesel production instead the homogenously catalyzed transesterification of vegetable oil. The pure CaO or CaO mixed with some other metal oxide due to its low solubility in methanol, FAME and glycerol, low cost and availability, is one of the most promising among the proposed heterogeneous catalysts. Solid catalysts containing CaO usually fulfill a number of important requirements, such as high activity at mild temperature, marginal leaching of Ca cations, long life activity, reusability in transesterification of vegetable oil and easy recovery from the final products of trancesterification (FAME and glycerol). This review is focused on the recent application of pure CaO or CaO in complex catalyst structure and their use as heterogeneous base catalysts for biodiesel synthesis and suitability for industrial application.
PB  - Savez hemijskih inženjera, Beograd
T2  - Chemical Industry & Chemical Engineering Quarterly
T1  - Calcium oxide based catalysts for biodiesel production: a review
EP  - 408
IS  - 4
SP  - 391
VL  - 22
DO  - 10.2298/CICEQ160203010K
ER  - 

@article{
author = "Kesić, Željka and Lukić, Ivana and Zdujić, Miodrag and Mojović, Ljiljana and Skala, Dejan",
year = "2016",
abstract = "Vegetable oils are mainly esters of fatty acids and glycerol, which can be converted to fatty acid methyl esters (FAME), also known as biodiesel, by the transesterification reaction with methanol. In order to attain environmental benignity, much attention has been focused in the last decades on utilizing heterogeneous catalysts for biodiesel production instead the homogenously catalyzed transesterification of vegetable oil. The pure CaO or CaO mixed with some other metal oxide due to its low solubility in methanol, FAME and glycerol, low cost and availability, is one of the most promising among the proposed heterogeneous catalysts. Solid catalysts containing CaO usually fulfill a number of important requirements, such as high activity at mild temperature, marginal leaching of Ca cations, long life activity, reusability in transesterification of vegetable oil and easy recovery from the final products of trancesterification (FAME and glycerol). This review is focused on the recent application of pure CaO or CaO in complex catalyst structure and their use as heterogeneous base catalysts for biodiesel synthesis and suitability for industrial application.",
publisher = "Savez hemijskih inženjera, Beograd",
journal = "Chemical Industry & Chemical Engineering Quarterly",
title = "Calcium oxide based catalysts for biodiesel production: a review",
pages = "408-391",
number = "4",
volume = "22",
doi = "10.2298/CICEQ160203010K"
}

Kesić, Ž., Lukić, I., Zdujić, M., Mojović, L.,& Skala, D.. (2016). Calcium oxide based catalysts for biodiesel production: a review. in Chemical Industry & Chemical Engineering Quarterly
Savez hemijskih inženjera, Beograd., 22(4), 391-408.
https://doi.org/10.2298/CICEQ160203010K

Kesić Ž, Lukić I, Zdujić M, Mojović L, Skala D. Calcium oxide based catalysts for biodiesel production: a review. in Chemical Industry & Chemical Engineering Quarterly. 2016;22(4):391-408.
doi:10.2298/CICEQ160203010K .

Kesić, Željka, Lukić, Ivana, Zdujić, Miodrag, Mojović, Ljiljana, Skala, Dejan, "Calcium oxide based catalysts for biodiesel production: a review" in Chemical Industry & Chemical Engineering Quarterly, 22, no. 4 (2016):391-408,
https://doi.org/10.2298/CICEQ160203010K . .

TY  - JOUR
AU  - Kesić, Željka
AU  - Lukić, Ivana
AU  - Zdujić, Miodrag
AU  - Jovalekić, Čedomir
AU  - Veljković, Vlada B.
AU  - Skala, Dejan
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3383
AB  - Calcium-containing perovskites CaTiO3, CaMnO3, CaZrO3 and Ca2Fe2O5 were synthesized by calcination of mechanochemically treated stoichiometric mixtures of CaCO3 and either TiO2, MnO2, ZrO2 or Fe2O3 powders. X-ray diffraction analysis revealed a pure single perovskite phase for all four samples after calcination. This study proved that the pure perovskite phase exhibited low or no catalytic activity at 60 degrees C for the methanolysis of sunflower oil. However, at 165 degrees C FAME yield of more than 90% was reached after 2 h using CaTiO3, CaMnO3 and CaZrO3 as catalyst. Contrary to inactive pure perovskites at 60 degrees C, the CaTiO3 and Ca2Fe2O5 samples containing a very small amount of "free" CaO also showed methanolysis activity at 60 degrees C. This fact can be used to explain some contradictory statements reported in literature related to the perovskites as catalyst for biodiesel synthesis at mild temperatures.
PB  - Elsevier Science Bv, Amsterdam
T2  - Fuel Processing Technology
T1  - Assessment of CaTiO3, CaMnO3, CaZrO3 and Ca2Fe2O5 perovskites as heterogeneous base catalysts for biodiesel synthesis
EP  - 168
SP  - 162
VL  - 143
DO  - 10.1016/j.fuproc.2015.11.018
ER  - 

@article{
author = "Kesić, Željka and Lukić, Ivana and Zdujić, Miodrag and Jovalekić, Čedomir and Veljković, Vlada B. and Skala, Dejan",
year = "2016",
abstract = "Calcium-containing perovskites CaTiO3, CaMnO3, CaZrO3 and Ca2Fe2O5 were synthesized by calcination of mechanochemically treated stoichiometric mixtures of CaCO3 and either TiO2, MnO2, ZrO2 or Fe2O3 powders. X-ray diffraction analysis revealed a pure single perovskite phase for all four samples after calcination. This study proved that the pure perovskite phase exhibited low or no catalytic activity at 60 degrees C for the methanolysis of sunflower oil. However, at 165 degrees C FAME yield of more than 90% was reached after 2 h using CaTiO3, CaMnO3 and CaZrO3 as catalyst. Contrary to inactive pure perovskites at 60 degrees C, the CaTiO3 and Ca2Fe2O5 samples containing a very small amount of "free" CaO also showed methanolysis activity at 60 degrees C. This fact can be used to explain some contradictory statements reported in literature related to the perovskites as catalyst for biodiesel synthesis at mild temperatures.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Fuel Processing Technology",
title = "Assessment of CaTiO3, CaMnO3, CaZrO3 and Ca2Fe2O5 perovskites as heterogeneous base catalysts for biodiesel synthesis",
pages = "168-162",
volume = "143",
doi = "10.1016/j.fuproc.2015.11.018"
}

Kesić, Ž., Lukić, I., Zdujić, M., Jovalekić, Č., Veljković, V. B.,& Skala, D.. (2016). Assessment of CaTiO3, CaMnO3, CaZrO3 and Ca2Fe2O5 perovskites as heterogeneous base catalysts for biodiesel synthesis. in Fuel Processing Technology
Elsevier Science Bv, Amsterdam., 143, 162-168.
https://doi.org/10.1016/j.fuproc.2015.11.018

Kesić Ž, Lukić I, Zdujić M, Jovalekić Č, Veljković VB, Skala D. Assessment of CaTiO3, CaMnO3, CaZrO3 and Ca2Fe2O5 perovskites as heterogeneous base catalysts for biodiesel synthesis. in Fuel Processing Technology. 2016;143:162-168.
doi:10.1016/j.fuproc.2015.11.018 .

Kesić, Željka, Lukić, Ivana, Zdujić, Miodrag, Jovalekić, Čedomir, Veljković, Vlada B., Skala, Dejan, "Assessment of CaTiO3, CaMnO3, CaZrO3 and Ca2Fe2O5 perovskites as heterogeneous base catalysts for biodiesel synthesis" in Fuel Processing Technology, 143 (2016):162-168,
https://doi.org/10.1016/j.fuproc.2015.11.018 . .

TY  - JOUR
AU  - Lukić, Ivana
AU  - Kesić, Željka
AU  - Zdujić, Miodrag
AU  - Skala, Dejan
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3400
AB  - In the present work, calcium diglyceroxide (CaDG) was synthesized by mechanochemical treatment of CaO dispersed in glycerol, and characterized by X-ray diffraction (XRD), thermal analysis (TGA/DTA), infrared spectroscopy (FTIR), and Hammett indicator method for base strength determination. The obtained CaDG was tested as a catalyst in the methanolysis of sunflower oil under different working conditions: catalyst amount, agitation speed, temperature and methanol to oil molar ratio. The main advantage of CaDG used as a catalyst in methanolysis is related to the initial rate of methanolysis. According to many previously reported data in literature the mass transfer resistance controls the overall rate of methanolysis, but it is not observed with CaDG used as catalyst. Recently developed kinetic model that describes the complex methanolysis process was successfully applied for this system and model parameters were determined, supporting the explanation of the physical effect of the CaDG catalyst on the reduction of mass transfer resistance and increasing the rate of methanolysis. The absence of mass transfer rate at the beginning of process is a consequence of the nature of the CaDG, which is adsorbed at the droplet interfaces between methanol and oil leading to the formation of fine dispersion of these two immiscible liquids.
PB  - Elsevier Sci Ltd, Oxford
T2  - Fuel
T1  - Calcium diglyceroxide synthesized by mechanochemical treatment, its characterization and application as catalyst for fatty acid methyl esters production
EP  - 165
SP  - 159
VL  - 165
DO  - 10.1016/j.fuel.2015.10.063
ER  - 

@article{
author = "Lukić, Ivana and Kesić, Željka and Zdujić, Miodrag and Skala, Dejan",
year = "2016",
abstract = "In the present work, calcium diglyceroxide (CaDG) was synthesized by mechanochemical treatment of CaO dispersed in glycerol, and characterized by X-ray diffraction (XRD), thermal analysis (TGA/DTA), infrared spectroscopy (FTIR), and Hammett indicator method for base strength determination. The obtained CaDG was tested as a catalyst in the methanolysis of sunflower oil under different working conditions: catalyst amount, agitation speed, temperature and methanol to oil molar ratio. The main advantage of CaDG used as a catalyst in methanolysis is related to the initial rate of methanolysis. According to many previously reported data in literature the mass transfer resistance controls the overall rate of methanolysis, but it is not observed with CaDG used as catalyst. Recently developed kinetic model that describes the complex methanolysis process was successfully applied for this system and model parameters were determined, supporting the explanation of the physical effect of the CaDG catalyst on the reduction of mass transfer resistance and increasing the rate of methanolysis. The absence of mass transfer rate at the beginning of process is a consequence of the nature of the CaDG, which is adsorbed at the droplet interfaces between methanol and oil leading to the formation of fine dispersion of these two immiscible liquids.",
publisher = "Elsevier Sci Ltd, Oxford",
journal = "Fuel",
title = "Calcium diglyceroxide synthesized by mechanochemical treatment, its characterization and application as catalyst for fatty acid methyl esters production",
pages = "165-159",
volume = "165",
doi = "10.1016/j.fuel.2015.10.063"
}

Lukić, I., Kesić, Ž., Zdujić, M.,& Skala, D.. (2016). Calcium diglyceroxide synthesized by mechanochemical treatment, its characterization and application as catalyst for fatty acid methyl esters production. in Fuel
Elsevier Sci Ltd, Oxford., 165, 159-165.
https://doi.org/10.1016/j.fuel.2015.10.063

Lukić I, Kesić Ž, Zdujić M, Skala D. Calcium diglyceroxide synthesized by mechanochemical treatment, its characterization and application as catalyst for fatty acid methyl esters production. in Fuel. 2016;165:159-165.
doi:10.1016/j.fuel.2015.10.063 .

Lukić, Ivana, Kesić, Željka, Zdujić, Miodrag, Skala, Dejan, "Calcium diglyceroxide synthesized by mechanochemical treatment, its characterization and application as catalyst for fatty acid methyl esters production" in Fuel, 165 (2016):159-165,
https://doi.org/10.1016/j.fuel.2015.10.063 . .

TY  - JOUR
AU  - Kesić, Željka
AU  - Lukić, Ivana
AU  - Zdujić, Miodrag
AU  - Jovalekić, Čedomir
AU  - Liu, Hui
AU  - Skala, Dejan
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2921
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.
AB  - Cilj ovih istraživanja bio je da se pripremi CaO·ZnO katalizator koji sadrži malu količinu K2CO3 i analizira njegova aktivnost u sintezi biodizela. Katalizator je pripremljen prema sledećoj proceduri: CaO i ZnO (molski odnos 1:2), voda i K2CO3 (u različitoj količini) su tretirani mehanohemijski i nakon mlevenja zagrevani na 700 °C u atmosferi vazduha da bi se dobila smeša oksida CaO·ZnO/xK2CO3 (x = 0, 1, 2 i 4 mol K2CO3 na 10 mol CaO). Karakterizacija pripremljenih katalizatora izvršena je metodama rendgenske difrakcije (XRD), indukovane kuplovane plazme (ICP), spektroskopije fotoelektrona dobijenih X-zracima (XPS), termogravimetrijske analize (TGA), infracrvene spektroskopije (FTIR), skenirajuće elektronske mikroskopije i energetske disperzione spektroskopije (SEM/EDS), raspodele veličine čestica (PSLD), merenjem rastvorljivosti katalizatora odnosno Ca, Zn i K jona u metanolu, kao i određivanjem njihove baznosti (metodom Hametovih indikatora). Pripremljeni CaO·ZnO/xK2CO3 kompozitni prahovi testirani su kao katalizatori u reakciji metanolize suncokretovog ulja na 70 °C, pri molarnom odnosu suncokretovog ulja i metanola od 1:10 i sa 2 mas.% katalizatora u odnosu na masu ulja. Pokazano je da prisustvo K2CO3 u pripremljenim uzorcima povećava aktivnost katalizatora i da je takav efekat posledica homogeno-heterogene katalize u sintezi biodizela.
PB  - Association of the Chemical Engineers of Serbia
T2  - Chemical Industry & Chemical Engineering Quarterly
T1  - Mechanochemical synthesis of CaO·ZnO.K2CO3 catalyst: Characterization and activity for methanolysis of sunflower oil
T1  - Mehanohemijska sinteza CaO·ZnO.K2CO3, katalizatora - karakterizacija i aktivnost u metanolizi suncokretovog ulja
EP  - 12
IS  - 1-1
SP  - 1
VL  - 21
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., Cilj ovih istraživanja bio je da se pripremi CaO·ZnO katalizator koji sadrži malu količinu K2CO3 i analizira njegova aktivnost u sintezi biodizela. Katalizator je pripremljen prema sledećoj proceduri: CaO i ZnO (molski odnos 1:2), voda i K2CO3 (u različitoj količini) su tretirani mehanohemijski i nakon mlevenja zagrevani na 700 °C u atmosferi vazduha da bi se dobila smeša oksida CaO·ZnO/xK2CO3 (x = 0, 1, 2 i 4 mol K2CO3 na 10 mol CaO). Karakterizacija pripremljenih katalizatora izvršena je metodama rendgenske difrakcije (XRD), indukovane kuplovane plazme (ICP), spektroskopije fotoelektrona dobijenih X-zracima (XPS), termogravimetrijske analize (TGA), infracrvene spektroskopije (FTIR), skenirajuće elektronske mikroskopije i energetske disperzione spektroskopije (SEM/EDS), raspodele veličine čestica (PSLD), merenjem rastvorljivosti katalizatora odnosno Ca, Zn i K jona u metanolu, kao i određivanjem njihove baznosti (metodom Hametovih indikatora). Pripremljeni CaO·ZnO/xK2CO3 kompozitni prahovi testirani su kao katalizatori u reakciji metanolize suncokretovog ulja na 70 °C, pri molarnom odnosu suncokretovog ulja i metanola od 1:10 i sa 2 mas.% katalizatora u odnosu na masu ulja. Pokazano je da prisustvo K2CO3 u pripremljenim uzorcima povećava aktivnost katalizatora i da je takav efekat posledica homogeno-heterogene katalize u sintezi biodizela.",
publisher = "Association of the Chemical Engineers of Serbia",
journal = "Chemical Industry & Chemical Engineering Quarterly",
title = "Mechanochemical synthesis of CaO·ZnO.K2CO3 catalyst: Characterization and activity for methanolysis of sunflower oil, Mehanohemijska sinteza CaO·ZnO.K2CO3, katalizatora - karakterizacija i aktivnost u metanolizi suncokretovog ulja",
pages = "12-1",
number = "1-1",
volume = "21",
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 & Chemical Engineering Quarterly
Association of the Chemical Engineers of Serbia., 21(1-1), 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 & Chemical Engineering Quarterly. 2015;21(1-1):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 & Chemical Engineering Quarterly, 21, no. 1-1 (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  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2608
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  - Association of the Chemical Engineers of Serbia
T2  - Chemical Industry & 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
EP  - 439
IS  - 3
SP  - 425
VL  - 20
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 = "Association of the Chemical Engineers of Serbia",
journal = "Chemical Industry & 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",
pages = "439-425",
number = "3",
volume = "20",
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 & Chemical Engineering Quarterly
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 & 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 & Chemical Engineering Quarterly, 20, no. 3 (2014):425-439,
https://doi.org/10.2298/CICEQ130514025L . .

TY  - JOUR
AU  - Lukić, Ivana
AU  - Kesić, Željka
AU  - Skala, Dejan
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2747
AB  - A heterogeneous catalyst, ZnO supported on alumina/silica, was synthesized by the sol-gel method. The prepared catalysts were employed for methanolysis of sunflower oil. Effects of various supports as well as calcination temperature were evaluated following the kinetics of the reaction. Simple first-order irreversible and reversible reaction models were applied to determine the reaction rate constant. The results proved that under optimized conditions the catalyst exhibited good activity in the methanolysis of sunflower oil and the kinetics of the methanolysis process could be expressed by the first-order reversible reaction model. For other catalysts with lower activity, the first-order irreversible reaction model could be successfully applied to describe well the process kinetics.
PB  - Wiley-VCH Verlag Gmbh, Weinheim
T2  - Chemical Engineering & Technology
T1  - Kinetics of Heterogeneous Biodiesel Synthesis Using Supported ZnO as Catalyst
EP  - 1884
IS  - 11
SP  - 1879
VL  - 37
DO  - 10.1002/ceat.201300714
ER  - 

@article{
author = "Lukić, Ivana and Kesić, Željka and Skala, Dejan",
year = "2014",
abstract = "A heterogeneous catalyst, ZnO supported on alumina/silica, was synthesized by the sol-gel method. The prepared catalysts were employed for methanolysis of sunflower oil. Effects of various supports as well as calcination temperature were evaluated following the kinetics of the reaction. Simple first-order irreversible and reversible reaction models were applied to determine the reaction rate constant. The results proved that under optimized conditions the catalyst exhibited good activity in the methanolysis of sunflower oil and the kinetics of the methanolysis process could be expressed by the first-order reversible reaction model. For other catalysts with lower activity, the first-order irreversible reaction model could be successfully applied to describe well the process kinetics.",
publisher = "Wiley-VCH Verlag Gmbh, Weinheim",
journal = "Chemical Engineering & Technology",
title = "Kinetics of Heterogeneous Biodiesel Synthesis Using Supported ZnO as Catalyst",
pages = "1884-1879",
number = "11",
volume = "37",
doi = "10.1002/ceat.201300714"
}

Lukić, I., Kesić, Ž.,& Skala, D.. (2014). Kinetics of Heterogeneous Biodiesel Synthesis Using Supported ZnO as Catalyst. in Chemical Engineering & Technology
Wiley-VCH Verlag Gmbh, Weinheim., 37(11), 1879-1884.
https://doi.org/10.1002/ceat.201300714

Lukić I, Kesić Ž, Skala D. Kinetics of Heterogeneous Biodiesel Synthesis Using Supported ZnO as Catalyst. in Chemical Engineering & Technology. 2014;37(11):1879-1884.
doi:10.1002/ceat.201300714 .

Lukić, Ivana, Kesić, Željka, Skala, Dejan, "Kinetics of Heterogeneous Biodiesel Synthesis Using Supported ZnO as Catalyst" in Chemical Engineering & Technology, 37, no. 11 (2014):1879-1884,
https://doi.org/10.1002/ceat.201300714 . .

TY  - CONF
AU  - Kesić, Željka
AU  - Lukić, Ivana
AU  - Zdujić, Miodrag
AU  - Skala, Dejan
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2574
PB  - Czech Society of Chemical Engineering
C3  - 21st International Congress of Chemical and Process Engineering, CHISA 2014 and 17th Conference on P
T1  - Homogeneous-heterogeneous catalytic effect of CaO · ZnO/K2CO3 during biodiesel synthesis
SP  - 233
VL  - 1
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2574
ER  - 

@conference{
author = "Kesić, Željka and Lukić, Ivana and Zdujić, Miodrag and Skala, Dejan",
year = "2014",
publisher = "Czech Society of Chemical Engineering",
journal = "21st International Congress of Chemical and Process Engineering, CHISA 2014 and 17th Conference on P",
title = "Homogeneous-heterogeneous catalytic effect of CaO · ZnO/K2CO3 during biodiesel synthesis",
pages = "233",
volume = "1",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2574"
}

Kesić, Ž., Lukić, I., Zdujić, M.,& Skala, D.. (2014). Homogeneous-heterogeneous catalytic effect of CaO · ZnO/K2CO3 during biodiesel synthesis. in 21st International Congress of Chemical and Process Engineering, CHISA 2014 and 17th Conference on P
Czech Society of Chemical Engineering., 1, 233.
https://hdl.handle.net/21.15107/rcub_technorep_2574

Kesić Ž, Lukić I, Zdujić M, Skala D. Homogeneous-heterogeneous catalytic effect of CaO · ZnO/K2CO3 during biodiesel synthesis. in 21st International Congress of Chemical and Process Engineering, CHISA 2014 and 17th Conference on P. 2014;1:233.
https://hdl.handle.net/21.15107/rcub_technorep_2574 .

Kesić, Željka, Lukić, Ivana, Zdujić, Miodrag, Skala, Dejan, "Homogeneous-heterogeneous catalytic effect of CaO · ZnO/K2CO3 during biodiesel synthesis" in 21st International Congress of Chemical and Process Engineering, CHISA 2014 and 17th Conference on P, 1 (2014):233,
https://hdl.handle.net/21.15107/rcub_technorep_2574 .

TY  - CONF
AU  - Lukić, Ivana
AU  - Kesić, Željka
AU  - Zdujić, Miodrag
AU  - Skala, Dejan
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2573
PB  - Czech Society of Chemical Engineering
C3  - 21st International Congress of Chemical and Process Engineering, CHISA 2014 and 17th Conference on P
T1  - Pretreatment of used vegetable oil using CaO and CaO-ZnO for biodiesel production
SP  - 347
VL  - 1
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2573
ER  - 

@conference{
author = "Lukić, Ivana and Kesić, Željka and Zdujić, Miodrag and Skala, Dejan",
year = "2014",
publisher = "Czech Society of Chemical Engineering",
journal = "21st International Congress of Chemical and Process Engineering, CHISA 2014 and 17th Conference on P",
title = "Pretreatment of used vegetable oil using CaO and CaO-ZnO for biodiesel production",
pages = "347",
volume = "1",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2573"
}

Lukić, I., Kesić, Ž., Zdujić, M.,& Skala, D.. (2014). Pretreatment of used vegetable oil using CaO and CaO-ZnO for biodiesel production. in 21st International Congress of Chemical and Process Engineering, CHISA 2014 and 17th Conference on P
Czech Society of Chemical Engineering., 1, 347.
https://hdl.handle.net/21.15107/rcub_technorep_2573

Lukić I, Kesić Ž, Zdujić M, Skala D. Pretreatment of used vegetable oil using CaO and CaO-ZnO for biodiesel production. in 21st International Congress of Chemical and Process Engineering, CHISA 2014 and 17th Conference on P. 2014;1:347.
https://hdl.handle.net/21.15107/rcub_technorep_2573 .

Lukić, Ivana, Kesić, Željka, Zdujić, Miodrag, Skala, Dejan, "Pretreatment of used vegetable oil using CaO and CaO-ZnO for biodiesel production" in 21st International Congress of Chemical and Process Engineering, CHISA 2014 and 17th Conference on P, 1 (2014):347,
https://hdl.handle.net/21.15107/rcub_technorep_2573 .

TY  - JOUR
AU  - Lukić, Ivana
AU  - Kesić, Željka
AU  - Maksimović, Svetolik
AU  - Zdujić, Miodrag
AU  - Liu, Hui
AU  - Krstić, Jugoslav
AU  - Skala, Dejan
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2423
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·ZnO
EP  - 378
SP  - 367
VL  - 113
DO  - 10.1016/j.fuel.2013.05.093
ER  - 

@article{
author = "Lukić, Ivana and Kesić, Željka 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·ZnO",
pages = "378-367",
volume = "113",
doi = "10.1016/j.fuel.2013.05.093"
}

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

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

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

TY  - JOUR
AU  - Maksimović, Svetolik
AU  - Kesić, Željka
AU  - Lukić, Ivana
AU  - Milovanović, Stoja
AU  - Ristić, Mihailo S.
AU  - Skala, Dejan
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2498
AB  - Yield and composition of curry flower (Helichrysum italicum) and sage leaves (Salvia officinalis) extract obtained by supercritical CO2 extraction (SFE) at 15 MPa and 40 degrees C were analyzed and compared to composition of curry flowers and sage essential oil isolated by hydrodistillation. Furthermore, the SFE performed using a mixture of curry flowers and sage plant and SFE of mixture of curry flowers and essential oil of sage were analyzed, too. It was shown that the average selectivity of monoterpenes and some individual sesquiterpenes and diterpenes present in pure sage or pure curry extract were significantly changed when mixture of these plants was used for SFE. The goal of SFE realized with mixture of curry flowers and sage essential oil was to explain effect of essential oil used as co-solvent changing the solubility of different compounds or characteristic group of terpenes in supercritical CO2. Increased extraction of heavier compounds from curry flower which is actually not present in pure essential oil of sage was also detected. The pseudo-kinetic model was proposed and corresponding parameters which define the rate of extraction were determined and compared to the parameters obtained according to Sovova's model usually used in literature for predicting yield of SFE from different plants.
PB  - Elsevier, Amsterdam
T2  - Journal of Supercritical Fluids
T1  - Supercritical fluid extraction of curry flowers, sage leaves, and their mixture
EP  - 12
SP  - 1
VL  - 84
DO  - 10.1016/j.supflu.2013.09.003
ER  - 

@article{
author = "Maksimović, Svetolik and Kesić, Željka and Lukić, Ivana and Milovanović, Stoja and Ristić, Mihailo S. and Skala, Dejan",
year = "2013",
abstract = "Yield and composition of curry flower (Helichrysum italicum) and sage leaves (Salvia officinalis) extract obtained by supercritical CO2 extraction (SFE) at 15 MPa and 40 degrees C were analyzed and compared to composition of curry flowers and sage essential oil isolated by hydrodistillation. Furthermore, the SFE performed using a mixture of curry flowers and sage plant and SFE of mixture of curry flowers and essential oil of sage were analyzed, too. It was shown that the average selectivity of monoterpenes and some individual sesquiterpenes and diterpenes present in pure sage or pure curry extract were significantly changed when mixture of these plants was used for SFE. The goal of SFE realized with mixture of curry flowers and sage essential oil was to explain effect of essential oil used as co-solvent changing the solubility of different compounds or characteristic group of terpenes in supercritical CO2. Increased extraction of heavier compounds from curry flower which is actually not present in pure essential oil of sage was also detected. The pseudo-kinetic model was proposed and corresponding parameters which define the rate of extraction were determined and compared to the parameters obtained according to Sovova's model usually used in literature for predicting yield of SFE from different plants.",
publisher = "Elsevier, Amsterdam",
journal = "Journal of Supercritical Fluids",
title = "Supercritical fluid extraction of curry flowers, sage leaves, and their mixture",
pages = "12-1",
volume = "84",
doi = "10.1016/j.supflu.2013.09.003"
}

Maksimović, S., Kesić, Ž., Lukić, I., Milovanović, S., Ristić, M. S.,& Skala, D.. (2013). Supercritical fluid extraction of curry flowers, sage leaves, and their mixture. in Journal of Supercritical Fluids
Elsevier, Amsterdam., 84, 1-12.
https://doi.org/10.1016/j.supflu.2013.09.003

Maksimović S, Kesić Ž, Lukić I, Milovanović S, Ristić MS, Skala D. Supercritical fluid extraction of curry flowers, sage leaves, and their mixture. in Journal of Supercritical Fluids. 2013;84:1-12.
doi:10.1016/j.supflu.2013.09.003 .

Maksimović, Svetolik, Kesić, Željka, Lukić, Ivana, Milovanović, Stoja, Ristić, Mihailo S., Skala, Dejan, "Supercritical fluid extraction of curry flowers, sage leaves, and their mixture" in Journal of Supercritical Fluids, 84 (2013):1-12,
https://doi.org/10.1016/j.supflu.2013.09.003 . .

TY  - JOUR
AU  - Kesić, Željka
AU  - Lukić, Ivana
AU  - Brkić, Dragana
AU  - Rogan, Jelena
AU  - Zdujić, Miodrag
AU  - Liu, Hui
AU  - Skala, Dejan
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2129
AB  - In this study, the synthesis of biodiesel or fatty acid methyl esters (FAME) from sunflower oil and methanol using CaO center dot ZnO catalyst was investigated. Catalyst was synthesized by ball milling of Ca(OH)(2) and ZnO powder mixture with the addition of water (BMH), as well as solely by ball milling of mentioned powders (BM) and subsequent calcination at 700 degrees C in air atmosphere. For comparison, the CaO center dot ZnO mixed oxide was also prepared using usual coprecipitation procedure (CP) followed by calcination at 700 degrees C of the formed calcium zinc hydroxide hydrate. The BMH, BM and CP catalysts were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), infrared spectroscopy (FTIR), particle size distribution measurement and scanning electron microscopy (SEM and SEM-EDS). In addition, specific surface area (BET), solubility in methanol at 60 degrees C and alkalinity (Hammett indicator method) were also determined. The activity of BMH, BM and CP catalysts for biodiesel synthesis were tested at 60 degrees 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.
PB  - Elsevier, Amsterdam
T2  - Applied Catalysis A-General
T1  - Mechanochemical preparation and characterization of CaO·ZnO used as catalyst for biodiesel synthesis
EP  - 65
SP  - 58
VL  - 427-428
DO  - 10.1016/j.apcata.2012.03.032
ER  - 

@article{
author = "Kesić, Željka and Lukić, Ivana and Brkić, Dragana and Rogan, Jelena and Zdujić, Miodrag and Liu, Hui and Skala, Dejan",
year = "2012",
abstract = "In this study, the synthesis of biodiesel or fatty acid methyl esters (FAME) from sunflower oil and methanol using CaO center dot ZnO catalyst was investigated. Catalyst was synthesized by ball milling of Ca(OH)(2) and ZnO powder mixture with the addition of water (BMH), as well as solely by ball milling of mentioned powders (BM) and subsequent calcination at 700 degrees C in air atmosphere. For comparison, the CaO center dot ZnO mixed oxide was also prepared using usual coprecipitation procedure (CP) followed by calcination at 700 degrees C of the formed calcium zinc hydroxide hydrate. The BMH, BM and CP catalysts were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), infrared spectroscopy (FTIR), particle size distribution measurement and scanning electron microscopy (SEM and SEM-EDS). In addition, specific surface area (BET), solubility in methanol at 60 degrees C and alkalinity (Hammett indicator method) were also determined. The activity of BMH, BM and CP catalysts for biodiesel synthesis were tested at 60 degrees 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.",
publisher = "Elsevier, Amsterdam",
journal = "Applied Catalysis A-General",
title = "Mechanochemical preparation and characterization of CaO·ZnO used as catalyst for biodiesel synthesis",
pages = "65-58",
volume = "427-428",
doi = "10.1016/j.apcata.2012.03.032"
}

Kesić, Ž., Lukić, I., Brkić, D., Rogan, J., Zdujić, M., Liu, H.,& Skala, D.. (2012). Mechanochemical preparation and characterization of CaO·ZnO used as catalyst for biodiesel synthesis. in Applied Catalysis A-General
Elsevier, Amsterdam., 427-428, 58-65.
https://doi.org/10.1016/j.apcata.2012.03.032

Kesić Ž, Lukić I, Brkić D, Rogan J, Zdujić M, Liu H, Skala D. Mechanochemical preparation and characterization of CaO·ZnO used as catalyst for biodiesel synthesis. in Applied Catalysis A-General. 2012;427-428:58-65.
doi:10.1016/j.apcata.2012.03.032 .

Kesić, Željka, Lukić, Ivana, Brkić, Dragana, Rogan, Jelena, Zdujić, Miodrag, Liu, Hui, Skala, Dejan, "Mechanochemical preparation and characterization of CaO·ZnO used as catalyst for biodiesel synthesis" in Applied Catalysis A-General, 427-428 (2012):58-65,
https://doi.org/10.1016/j.apcata.2012.03.032 . .

TY  - CONF
AU  - Kesić, Željka
AU  - Lukić, Ivana
AU  - Zdujić, Miodrag
AU  - Liu, Hui
AU  - Skala, Dejan
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2004
AB  - The transesterification of triglycerides (vegetable oil) with methanol using CaO·ZnO mixed oxides catalyst were conducted to produce Fatty Acid Methyl Esters (FAME), i.e. biodiesel. The 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 displayed good activity in the methanolysis of sunflower oil, with the yield of FAME  gt  90% after 4 hr of reaction. This is an abstract of a paper presented at the CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference PRES (Prague, Czech Republic 8/25-29/2012).
PB  - 20th International Congress of Chemical and Process Engineering, CHISA 2012 and 15th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction, PRES 2012
C3  - CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Co
T1  - Mechanochemically synthesized CaO·ZnO catalyst for biodiesel production
DO  - 10.1016/j.proeng.2012.07.509
ER  - 

@conference{
author = "Kesić, Željka and Lukić, Ivana and Zdujić, Miodrag and Liu, Hui and Skala, Dejan",
year = "2012",
abstract = "The transesterification of triglycerides (vegetable oil) with methanol using CaO·ZnO mixed oxides catalyst were conducted to produce Fatty Acid Methyl Esters (FAME), i.e. biodiesel. The 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 displayed good activity in the methanolysis of sunflower oil, with the yield of FAME  gt  90% after 4 hr of reaction. This is an abstract of a paper presented at the CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference PRES (Prague, Czech Republic 8/25-29/2012).",
publisher = "20th International Congress of Chemical and Process Engineering, CHISA 2012 and 15th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction, PRES 2012",
journal = "CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Co",
title = "Mechanochemically synthesized CaO·ZnO catalyst for biodiesel production",
doi = "10.1016/j.proeng.2012.07.509"
}

Kesić, Ž., Lukić, I., Zdujić, M., Liu, H.,& Skala, D.. (2012). Mechanochemically synthesized CaO·ZnO catalyst for biodiesel production. in CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Co
20th International Congress of Chemical and Process Engineering, CHISA 2012 and 15th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction, PRES 2012..
https://doi.org/10.1016/j.proeng.2012.07.509

Kesić Ž, Lukić I, Zdujić M, Liu H, Skala D. Mechanochemically synthesized CaO·ZnO catalyst for biodiesel production. in CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Co. 2012;.
doi:10.1016/j.proeng.2012.07.509 .

Kesić, Željka, Lukić, Ivana, Zdujić, Miodrag, Liu, Hui, Skala, Dejan, "Mechanochemically synthesized CaO·ZnO catalyst for biodiesel production" in CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Co (2012),
https://doi.org/10.1016/j.proeng.2012.07.509 . .

TY  - JOUR
AU  - Kesić, Željka
AU  - Lukić, Ivana
AU  - Zdujić, Miodrag
AU  - Liu, Hui
AU  - Skala, Dejan
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2247
AB  - The transesterification of triglycerides (vegetable oil) with methanol using CaO center dot 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 CaO and ZnO 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 degrees 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 degrees 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 Science Bv, Amsterdam
T2  - CHISA 2012
T1  - Mechanochemically synthesized CaO center dot ZnO catalyst for biodiesel production
EP  - 1178
SP  - 1169
VL  - 42
DO  - 10.1016/j.proeng.2012.07.509
ER  - 

@article{
author = "Kesić, Željka and Lukić, Ivana and Zdujić, Miodrag and Liu, Hui and Skala, Dejan",
year = "2012",
abstract = "The transesterification of triglycerides (vegetable oil) with methanol using CaO center dot 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 CaO and ZnO 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 degrees 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 degrees 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 Science Bv, Amsterdam",
journal = "CHISA 2012",
title = "Mechanochemically synthesized CaO center dot ZnO catalyst for biodiesel production",
pages = "1178-1169",
volume = "42",
doi = "10.1016/j.proeng.2012.07.509"
}

Kesić, Ž., Lukić, I., Zdujić, M., Liu, H.,& Skala, D.. (2012). Mechanochemically synthesized CaO center dot ZnO catalyst for biodiesel production. in CHISA 2012
Elsevier Science Bv, Amsterdam., 42, 1169-1178.
https://doi.org/10.1016/j.proeng.2012.07.509

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

Kesić, Željka, Lukić, Ivana, Zdujić, Miodrag, Liu, Hui, Skala, Dejan, "Mechanochemically synthesized CaO center dot ZnO catalyst for biodiesel production" in CHISA 2012, 42 (2012):1169-1178,
https://doi.org/10.1016/j.proeng.2012.07.509 . .