TY  - CHAP
AU  - Meyer, Florian
AU  - Stamenić, Marko
AU  - Žižović, Irena
AU  - Eggers, Rudolf
PY  - 2017
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3489
AB  - A new trend in mathematical modeling of supercritical extraction process from plant material is presented. The most of the previously published models considered properties of the fixed bed of plant material during the extraction to be constant. This assumption might be quite true in the case of plant materials with relatively low quantity of extractables. However, the fixed bed property change may occur in the case of extraction from material with high quantities of extractables. Recently, mathematical model which took into account particle density, bed porosity and particle diameter as variables was derived. In this chapter, the model is further improved by introducing variable solubility of the extract in supercritical fluid. On the basis of new experimental results on the binary equilibrium of the system supercritical fluid - extract present in solid, a relationship between solubility in supercritical fluid and oil content in solid was established. The new model was derived which took into account particle density, bed porosity, particle diameter and solubility in supercritical fluid as variables. The model was verified on results from experiments in which the kinetics of supercritical extraction from rapseed was analyzed. Parameters of the model showed expected behaviour with respect to the change of particle size. Further analysis, shown in this chapter, showed that, if the dependency of solubility from the concentration in the solid phase is not accounted for, the model tends to overestimate the yield of the extraction. The new model is so far, the most realistic model and one of the most demanding models regarding experimental work and mathematical tools for the description of mass transfer in fixed beds.
T2  - Mathematical Research Summaries
T1  - Advances in mathematical modeling of supercritical extraction processes
EP  - 102
SP  - 101
VL  - 2
UR  - https://hdl.handle.net/21.15107/rcub_technorep_3489
ER  - 

@inbook{
author = "Meyer, Florian and Stamenić, Marko and Žižović, Irena and Eggers, Rudolf",
year = "2017",
abstract = "A new trend in mathematical modeling of supercritical extraction process from plant material is presented. The most of the previously published models considered properties of the fixed bed of plant material during the extraction to be constant. This assumption might be quite true in the case of plant materials with relatively low quantity of extractables. However, the fixed bed property change may occur in the case of extraction from material with high quantities of extractables. Recently, mathematical model which took into account particle density, bed porosity and particle diameter as variables was derived. In this chapter, the model is further improved by introducing variable solubility of the extract in supercritical fluid. On the basis of new experimental results on the binary equilibrium of the system supercritical fluid - extract present in solid, a relationship between solubility in supercritical fluid and oil content in solid was established. The new model was derived which took into account particle density, bed porosity, particle diameter and solubility in supercritical fluid as variables. The model was verified on results from experiments in which the kinetics of supercritical extraction from rapseed was analyzed. Parameters of the model showed expected behaviour with respect to the change of particle size. Further analysis, shown in this chapter, showed that, if the dependency of solubility from the concentration in the solid phase is not accounted for, the model tends to overestimate the yield of the extraction. The new model is so far, the most realistic model and one of the most demanding models regarding experimental work and mathematical tools for the description of mass transfer in fixed beds.",
journal = "Mathematical Research Summaries",
booktitle = "Advances in mathematical modeling of supercritical extraction processes",
pages = "102-101",
volume = "2",
url = "https://hdl.handle.net/21.15107/rcub_technorep_3489"
}

Meyer, F., Stamenić, M., Žižović, I.,& Eggers, R.. (2017). Advances in mathematical modeling of supercritical extraction processes. in Mathematical Research Summaries, 2, 101-102.
https://hdl.handle.net/21.15107/rcub_technorep_3489

Meyer F, Stamenić M, Žižović I, Eggers R. Advances in mathematical modeling of supercritical extraction processes. in Mathematical Research Summaries. 2017;2:101-102.
https://hdl.handle.net/21.15107/rcub_technorep_3489 .

Meyer, Florian, Stamenić, Marko, Žižović, Irena, Eggers, Rudolf, "Advances in mathematical modeling of supercritical extraction processes" in Mathematical Research Summaries, 2 (2017):101-102,
https://hdl.handle.net/21.15107/rcub_technorep_3489 .

TY  - JOUR
AU  - Ivanović, Jasna
AU  - Meyer, Florian
AU  - Stamenić, Marko
AU  - Jaeger, Philip
AU  - Žižović, Irena
AU  - Eggers, Rudolf
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2665
AB  - A proper method was to be developed for the pretreatment of different types of natural materials in order to increase the efficiency of supercritical fluid extraction (SFE) regarding yield and active substance content. The effects of different mechanical pretreatments were investigated: flaking, impact plus shearing, and cutting plus grinding. Additionally, the influence of intermediate rapid gas decompression was studied. Significant effects of the applied pretreatments on the yield (increase by up to 1350 %) were shown for SFE of selected oilseeds, artemisia aerial parts, and the lichen Usnea barbata. Flaking was the most effective pretreatment for increasing the yield of SFE of fennel seeds, artemisia aerial parts, and Usnea lichen, while impact plus shearing was optimal for processing amaranth, milk thistle, and oat seeds. The use of defined optimal pretreatments led to notable increases in the contents of usnic acid (50 %) and artemisinin (300 %).
PB  - Wiley-VCH Verlag Gmbh, Weinheim
T2  - Chemical Engineering & Technology
T1  - Pretreatment of Natural Materials Used for Supercritical Fluid Extraction of Commercial Phytopharmaceuticals
EP  - 1611
IS  - 9
SP  - 1606
VL  - 37
DO  - 10.1002/ceat.201300715
ER  - 

@article{
author = "Ivanović, Jasna and Meyer, Florian and Stamenić, Marko and Jaeger, Philip and Žižović, Irena and Eggers, Rudolf",
year = "2014",
abstract = "A proper method was to be developed for the pretreatment of different types of natural materials in order to increase the efficiency of supercritical fluid extraction (SFE) regarding yield and active substance content. The effects of different mechanical pretreatments were investigated: flaking, impact plus shearing, and cutting plus grinding. Additionally, the influence of intermediate rapid gas decompression was studied. Significant effects of the applied pretreatments on the yield (increase by up to 1350 %) were shown for SFE of selected oilseeds, artemisia aerial parts, and the lichen Usnea barbata. Flaking was the most effective pretreatment for increasing the yield of SFE of fennel seeds, artemisia aerial parts, and Usnea lichen, while impact plus shearing was optimal for processing amaranth, milk thistle, and oat seeds. The use of defined optimal pretreatments led to notable increases in the contents of usnic acid (50 %) and artemisinin (300 %).",
publisher = "Wiley-VCH Verlag Gmbh, Weinheim",
journal = "Chemical Engineering & Technology",
title = "Pretreatment of Natural Materials Used for Supercritical Fluid Extraction of Commercial Phytopharmaceuticals",
pages = "1611-1606",
number = "9",
volume = "37",
doi = "10.1002/ceat.201300715"
}

Ivanović, J., Meyer, F., Stamenić, M., Jaeger, P., Žižović, I.,& Eggers, R.. (2014). Pretreatment of Natural Materials Used for Supercritical Fluid Extraction of Commercial Phytopharmaceuticals. in Chemical Engineering & Technology
Wiley-VCH Verlag Gmbh, Weinheim., 37(9), 1606-1611.
https://doi.org/10.1002/ceat.201300715

Ivanović J, Meyer F, Stamenić M, Jaeger P, Žižović I, Eggers R. Pretreatment of Natural Materials Used for Supercritical Fluid Extraction of Commercial Phytopharmaceuticals. in Chemical Engineering & Technology. 2014;37(9):1606-1611.
doi:10.1002/ceat.201300715 .

Ivanović, Jasna, Meyer, Florian, Stamenić, Marko, Jaeger, Philip, Žižović, Irena, Eggers, Rudolf, "Pretreatment of Natural Materials Used for Supercritical Fluid Extraction of Commercial Phytopharmaceuticals" in Chemical Engineering & Technology, 37, no. 9 (2014):1606-1611,
https://doi.org/10.1002/ceat.201300715 . .

TY  - CHAP
AU  - Meyer, Florian
AU  - Stamenić, Marko
AU  - Žižović, Irena
AU  - Eggers, Rudolf
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2568
AB  - A new trend in mathematical modeling of supercritical extraction process from plant material is presented.The most of the previously published models considered properties of the fixed bed of plant material during the extraction to be constant. This assumption might be quite true in the case of plant materials with relatively low quantity of extractables. However, the fixed bed property change may occur in the case of extraction from material with high quantities of extractables. Recently, mathematical model which took into account particle density, bed porosity and particle diameter as variables was derived. In this chapter, the model is further improved by introducing variable solubility of the extract in supercritical fluid. On the basis of new experimental results on the binary equilibrium of the system supercritical fluid - extract present in solid, a relationship between solubility in supercritical fluid and oil content in solid was established. The new model was derived which took into account particle density, bed porosity, particle diameter and solubility in supercritical fluid as variables. The model was verified on results from experiments in which the kintecis of supercritical extraction from rapseed was analyzed. Parameters of the model showed expected behaviour with respect to the change of particle size. Further analysis, shown in this chapter, showed that, if the dependency of solubility from the concentration in the solid phase is not accounted for, the model tends to overestimate the yield of the extraction.The new model is so far, the most realistic model and one of the most demanding models regarding experimental work and mathematical tools for the description of mass transfer in fixed beds.
T2  - Mathematical Modeling in Social Sciences and Engineering
T1  - Advances in Mathematical Modeling of Supercritical Extraction Processes
EP  - 70
SP  - 59
UR  - https://hdl.handle.net/21.15107/rcub_technorep_2568
ER  - 

@inbook{
author = "Meyer, Florian and Stamenić, Marko and Žižović, Irena and Eggers, Rudolf",
year = "2014",
abstract = "A new trend in mathematical modeling of supercritical extraction process from plant material is presented.The most of the previously published models considered properties of the fixed bed of plant material during the extraction to be constant. This assumption might be quite true in the case of plant materials with relatively low quantity of extractables. However, the fixed bed property change may occur in the case of extraction from material with high quantities of extractables. Recently, mathematical model which took into account particle density, bed porosity and particle diameter as variables was derived. In this chapter, the model is further improved by introducing variable solubility of the extract in supercritical fluid. On the basis of new experimental results on the binary equilibrium of the system supercritical fluid - extract present in solid, a relationship between solubility in supercritical fluid and oil content in solid was established. The new model was derived which took into account particle density, bed porosity, particle diameter and solubility in supercritical fluid as variables. The model was verified on results from experiments in which the kintecis of supercritical extraction from rapseed was analyzed. Parameters of the model showed expected behaviour with respect to the change of particle size. Further analysis, shown in this chapter, showed that, if the dependency of solubility from the concentration in the solid phase is not accounted for, the model tends to overestimate the yield of the extraction.The new model is so far, the most realistic model and one of the most demanding models regarding experimental work and mathematical tools for the description of mass transfer in fixed beds.",
journal = "Mathematical Modeling in Social Sciences and Engineering",
booktitle = "Advances in Mathematical Modeling of Supercritical Extraction Processes",
pages = "70-59",
url = "https://hdl.handle.net/21.15107/rcub_technorep_2568"
}

Meyer, F., Stamenić, M., Žižović, I.,& Eggers, R.. (2014). Advances in Mathematical Modeling of Supercritical Extraction Processes. in Mathematical Modeling in Social Sciences and Engineering, 59-70.
https://hdl.handle.net/21.15107/rcub_technorep_2568

Meyer F, Stamenić M, Žižović I, Eggers R. Advances in Mathematical Modeling of Supercritical Extraction Processes. in Mathematical Modeling in Social Sciences and Engineering. 2014;:59-70.
https://hdl.handle.net/21.15107/rcub_technorep_2568 .

Meyer, Florian, Stamenić, Marko, Žižović, Irena, Eggers, Rudolf, "Advances in Mathematical Modeling of Supercritical Extraction Processes" in Mathematical Modeling in Social Sciences and Engineering (2014):59-70,
https://hdl.handle.net/21.15107/rcub_technorep_2568 .

TY  - JOUR
AU  - Ivanović, Jasna
AU  - Meyer, Florian
AU  - Mišić, Dušan
AU  - Ašanin, Jelena
AU  - Jaeger, Philip
AU  - Žižović, Irena
AU  - Eggers, Rudolf
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5700
AB  - Multiplication and spreading of multiresistant pathogenic bacteria that cause fatal infections in humans and animals have boosted research on implementation of newer technologies for producing natural substances with strong antibacterial activities. In this study, SFE from lichen Usnea barbata was investigated for different pre-treatment methods with respect to extracts yield, usnic acid recovery and antibacterial activity against more than thirty methicillin resistant staphylococci strains. Extraction of U. barbata with subcritical carbon dioxide was studied as well. Extraction yield, usnic acid content and antibacterial activity of the extracts were strongly affected by the pre-treatment method. Intensive pre-treatment methods such as flaking and cutting + grinding caused a considerable comminution of the lichen thallus and enabled high extraction yields. On the other hand, mild pre-treatment of the lichen such as impact + shearing enabled isolation of extracts with lower MIC values. Experimental results indicated that extraction with liquid carbon dioxide at 30 MPa and 25 degrees C was the most favorable condition at which a satisfactory high extraction yield was obtained (2.08%). Extract isolated with liquid carbon dioxide had a high usnic acid content in the extract (632 g/kg) and a very strong antibacterial activity (average MIC of 19.11 mu g/mL). Antibacterial activity of all the extracts against tested strains was comparable to the pure usnic acid or even stronger. This study indicated a potential use of the supercritical extracts of U. barbata in pharmaceutical formulations for treatment of infections caused by staphylococci.
PB  - Elsevier, Amsterdam
T2  - Journal of Supercritical Fluids
T1  - Influence of different pre-treatment methods on isolation of extracts with strong antibacterial activity from lichen Usnea barbata using carbon dioxide as a solvent
EP  - 9
SP  - 1
VL  - 76
DO  - 10.1016/j.supflu.2013.01.005
ER  - 

@article{
author = "Ivanović, Jasna and Meyer, Florian and Mišić, Dušan and Ašanin, Jelena and Jaeger, Philip and Žižović, Irena and Eggers, Rudolf",
year = "2013",
abstract = "Multiplication and spreading of multiresistant pathogenic bacteria that cause fatal infections in humans and animals have boosted research on implementation of newer technologies for producing natural substances with strong antibacterial activities. In this study, SFE from lichen Usnea barbata was investigated for different pre-treatment methods with respect to extracts yield, usnic acid recovery and antibacterial activity against more than thirty methicillin resistant staphylococci strains. Extraction of U. barbata with subcritical carbon dioxide was studied as well. Extraction yield, usnic acid content and antibacterial activity of the extracts were strongly affected by the pre-treatment method. Intensive pre-treatment methods such as flaking and cutting + grinding caused a considerable comminution of the lichen thallus and enabled high extraction yields. On the other hand, mild pre-treatment of the lichen such as impact + shearing enabled isolation of extracts with lower MIC values. Experimental results indicated that extraction with liquid carbon dioxide at 30 MPa and 25 degrees C was the most favorable condition at which a satisfactory high extraction yield was obtained (2.08%). Extract isolated with liquid carbon dioxide had a high usnic acid content in the extract (632 g/kg) and a very strong antibacterial activity (average MIC of 19.11 mu g/mL). Antibacterial activity of all the extracts against tested strains was comparable to the pure usnic acid or even stronger. This study indicated a potential use of the supercritical extracts of U. barbata in pharmaceutical formulations for treatment of infections caused by staphylococci.",
publisher = "Elsevier, Amsterdam",
journal = "Journal of Supercritical Fluids",
title = "Influence of different pre-treatment methods on isolation of extracts with strong antibacterial activity from lichen Usnea barbata using carbon dioxide as a solvent",
pages = "9-1",
volume = "76",
doi = "10.1016/j.supflu.2013.01.005"
}

Ivanović, J., Meyer, F., Mišić, D., Ašanin, J., Jaeger, P., Žižović, I.,& Eggers, R.. (2013). Influence of different pre-treatment methods on isolation of extracts with strong antibacterial activity from lichen Usnea barbata using carbon dioxide as a solvent. in Journal of Supercritical Fluids
Elsevier, Amsterdam., 76, 1-9.
https://doi.org/10.1016/j.supflu.2013.01.005

Ivanović J, Meyer F, Mišić D, Ašanin J, Jaeger P, Žižović I, Eggers R. Influence of different pre-treatment methods on isolation of extracts with strong antibacterial activity from lichen Usnea barbata using carbon dioxide as a solvent. in Journal of Supercritical Fluids. 2013;76:1-9.
doi:10.1016/j.supflu.2013.01.005 .

Ivanović, Jasna, Meyer, Florian, Mišić, Dušan, Ašanin, Jelena, Jaeger, Philip, Žižović, Irena, Eggers, Rudolf, "Influence of different pre-treatment methods on isolation of extracts with strong antibacterial activity from lichen Usnea barbata using carbon dioxide as a solvent" in Journal of Supercritical Fluids, 76 (2013):1-9,
https://doi.org/10.1016/j.supflu.2013.01.005 . .

TY  - JOUR
AU  - Meyer, Florian
AU  - Stamenić, Marko
AU  - Žižović, Irena
AU  - Eggers, Rudolf
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2167
AB  - Properties of the fixed bed of plant material during the extraction with scCO(2) from rapeseed were investigated for the two types of mechanical pretreatments: flaking and impact milling. Obtained results indicated that particle density, bulk density of the bed and consequently the bed porosity changed during the extraction. In the case of flaked rapeseed, the change of particle diameter was also detected and quantified. On the basis of experimental data linear relationships between the particle density/bed porosity/mean particle diameter and oil content in solid were established. Mathematical model based on the mass balances for the supercritical and solid phase which took into account particle density, bed porosity and particle diameter (for flaked plant material) as variables was derived. The proposed model described experimental data with high accuracy. Possible error due to neglecting the change of the fixed bed properties was presented as well.
PB  - Elsevier Science Bv, Amsterdam
T2  - Journal of Supercritical Fluids
T1  - Fixed bed property changes during scCO(2) extraction of natural materials - Experiments and modeling
EP  - 149
SP  - 140
VL  - 72
DO  - 10.1016/j.supflu.2012.08.022
ER  - 

@article{
author = "Meyer, Florian and Stamenić, Marko and Žižović, Irena and Eggers, Rudolf",
year = "2012",
abstract = "Properties of the fixed bed of plant material during the extraction with scCO(2) from rapeseed were investigated for the two types of mechanical pretreatments: flaking and impact milling. Obtained results indicated that particle density, bulk density of the bed and consequently the bed porosity changed during the extraction. In the case of flaked rapeseed, the change of particle diameter was also detected and quantified. On the basis of experimental data linear relationships between the particle density/bed porosity/mean particle diameter and oil content in solid were established. Mathematical model based on the mass balances for the supercritical and solid phase which took into account particle density, bed porosity and particle diameter (for flaked plant material) as variables was derived. The proposed model described experimental data with high accuracy. Possible error due to neglecting the change of the fixed bed properties was presented as well.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Journal of Supercritical Fluids",
title = "Fixed bed property changes during scCO(2) extraction of natural materials - Experiments and modeling",
pages = "149-140",
volume = "72",
doi = "10.1016/j.supflu.2012.08.022"
}

Meyer, F., Stamenić, M., Žižović, I.,& Eggers, R.. (2012). Fixed bed property changes during scCO(2) extraction of natural materials - Experiments and modeling. in Journal of Supercritical Fluids
Elsevier Science Bv, Amsterdam., 72, 140-149.
https://doi.org/10.1016/j.supflu.2012.08.022

Meyer F, Stamenić M, Žižović I, Eggers R. Fixed bed property changes during scCO(2) extraction of natural materials - Experiments and modeling. in Journal of Supercritical Fluids. 2012;72:140-149.
doi:10.1016/j.supflu.2012.08.022 .

Meyer, Florian, Stamenić, Marko, Žižović, Irena, Eggers, Rudolf, "Fixed bed property changes during scCO(2) extraction of natural materials - Experiments and modeling" in Journal of Supercritical Fluids, 72 (2012):140-149,
https://doi.org/10.1016/j.supflu.2012.08.022 . .

TY  - JOUR
AU  - Meyer, Florian
AU  - Jaeger, Philip
AU  - Eggers, Rudolf
AU  - Stamenić, Marko
AU  - Milovanović, Stoja
AU  - Žižović, Irena
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2145
AB  - Pre-treatment of natural materials prior to their extraction strongly influences the efficiency of the process. Therefore, proper selection of pre-treatment method enables intensification of extraction process. Within this study "rapid gas decompression" (RGD) was investigated as a pretreatment method using carbon dioxide as working fluid. Oilseeds (rapeseed and sunflower seed), St. Johns Wort and Hop were studied as valuable raw materials for industrial application of supercritical fluid extraction. The sorption behaviour of carbon dioxide within the natural materials was examined gravimetrically under high pressure conditions between 5 and 26 MPa and at temperatures between 40 and 60 degrees C. It was observed that considerable amounts of carbon dioxide sorb within natural materials and a combination of dissolution within the solute phase and adsorption on the plant matrix occurs. RGD was used as a pre-treatment method prior to the extraction or as an intermediate treatment during the extraction process. The results showed that effect of RGD on extraction was the most pronounced for St. Johns Wort but also the extraction kinetics of the other materials were affected. Probable mechanisms occurring during RGD are discussed.
PB  - Elsevier Science Sa, Lausanne
T2  - Chemical Engineering and Processing-Process Intensification
T1  - Effect of CO2 pre-treatment on scCO(2) extraction of natural material
EP  - 45
SP  - 37
VL  - 56
DO  - 10.1016/j.cep.2012.02.003
ER  - 

@article{
author = "Meyer, Florian and Jaeger, Philip and Eggers, Rudolf and Stamenić, Marko and Milovanović, Stoja and Žižović, Irena",
year = "2012",
abstract = "Pre-treatment of natural materials prior to their extraction strongly influences the efficiency of the process. Therefore, proper selection of pre-treatment method enables intensification of extraction process. Within this study "rapid gas decompression" (RGD) was investigated as a pretreatment method using carbon dioxide as working fluid. Oilseeds (rapeseed and sunflower seed), St. Johns Wort and Hop were studied as valuable raw materials for industrial application of supercritical fluid extraction. The sorption behaviour of carbon dioxide within the natural materials was examined gravimetrically under high pressure conditions between 5 and 26 MPa and at temperatures between 40 and 60 degrees C. It was observed that considerable amounts of carbon dioxide sorb within natural materials and a combination of dissolution within the solute phase and adsorption on the plant matrix occurs. RGD was used as a pre-treatment method prior to the extraction or as an intermediate treatment during the extraction process. The results showed that effect of RGD on extraction was the most pronounced for St. Johns Wort but also the extraction kinetics of the other materials were affected. Probable mechanisms occurring during RGD are discussed.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Chemical Engineering and Processing-Process Intensification",
title = "Effect of CO2 pre-treatment on scCO(2) extraction of natural material",
pages = "45-37",
volume = "56",
doi = "10.1016/j.cep.2012.02.003"
}

Meyer, F., Jaeger, P., Eggers, R., Stamenić, M., Milovanović, S.,& Žižović, I.. (2012). Effect of CO2 pre-treatment on scCO(2) extraction of natural material. in Chemical Engineering and Processing-Process Intensification
Elsevier Science Sa, Lausanne., 56, 37-45.
https://doi.org/10.1016/j.cep.2012.02.003

Meyer F, Jaeger P, Eggers R, Stamenić M, Milovanović S, Žižović I. Effect of CO2 pre-treatment on scCO(2) extraction of natural material. in Chemical Engineering and Processing-Process Intensification. 2012;56:37-45.
doi:10.1016/j.cep.2012.02.003 .

Meyer, Florian, Jaeger, Philip, Eggers, Rudolf, Stamenić, Marko, Milovanović, Stoja, Žižović, Irena, "Effect of CO2 pre-treatment on scCO(2) extraction of natural material" in Chemical Engineering and Processing-Process Intensification, 56 (2012):37-45,
https://doi.org/10.1016/j.cep.2012.02.003 . .