Komatina, Mirko

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  • Komatina, Mirko (11)

Author's Bibliography

The kinetic study of juice industry residues drying process based on TGA-DTG experimental data

Milanović, Mihailo; Komatina, Mirko; Janković, Bojan; Stojiljković, Dragoslava; Manić, Nebojša

(2022)

TY  - JOUR
AU  - Milanović, Mihailo
AU  - Komatina, Mirko
AU  - Janković, Bojan
AU  - Stojiljković, Dragoslava
AU  - Manić, Nebojša
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10221
AB  - Sustainable development and mitigation of the climate changes are one of the main challenges of the circular economy, while the use of food industry residues could make an important contribution in tackling these challenges. In order to improve energy efficiency aspects of the industry residue treatment, generally, the drying process as the first step of the entire processing chain should be further analyzed. Regarding this, a comprehensive kinetic study was performed to provide the detailed mechanism of moisture removal from base raw material. Industrial residues from apple juice production were used for isothermal thermogravimetric analysis in the air atmosphere at different temperatures. Based on experimental data, different kinetic models were applied to determine kinetic parameters and dominant conversion functions. The dependence of the activation energy evaluated by Friedman’s isoconversional method on the conversion degree shows that the drying process is complex one. The mechanism of drying process and corresponding kinetic parameters were determined by multivariate nonlinear regression program (model-based analysis) and checked by modulated isothermal prediction (for quasi-isothermal conditions) and the isothermal prediction (for different isothermal conditions) tests. It was pointed out that temperature-dependent reaction step controlling overall mechanism represents releasing of CO2 which can suppress autocatalytic action of the ethylene, influencing the flavor and texture changes of the apple tissue. Obtained results can be used for prediction of the life-time of studied material, corresponding to selected temperatures and different conversion levels.
T2  - Journal of Thermal Analysis and Calorimetry
T1  - The kinetic study of juice industry residues drying process based on TGA-DTG experimental data
DO  - 10.1007/s10973-022-11289-5
ER  - 
@article{
author = "Milanović, Mihailo and Komatina, Mirko and Janković, Bojan and Stojiljković, Dragoslava and Manić, Nebojša",
year = "2022",
abstract = "Sustainable development and mitigation of the climate changes are one of the main challenges of the circular economy, while the use of food industry residues could make an important contribution in tackling these challenges. In order to improve energy efficiency aspects of the industry residue treatment, generally, the drying process as the first step of the entire processing chain should be further analyzed. Regarding this, a comprehensive kinetic study was performed to provide the detailed mechanism of moisture removal from base raw material. Industrial residues from apple juice production were used for isothermal thermogravimetric analysis in the air atmosphere at different temperatures. Based on experimental data, different kinetic models were applied to determine kinetic parameters and dominant conversion functions. The dependence of the activation energy evaluated by Friedman’s isoconversional method on the conversion degree shows that the drying process is complex one. The mechanism of drying process and corresponding kinetic parameters were determined by multivariate nonlinear regression program (model-based analysis) and checked by modulated isothermal prediction (for quasi-isothermal conditions) and the isothermal prediction (for different isothermal conditions) tests. It was pointed out that temperature-dependent reaction step controlling overall mechanism represents releasing of CO2 which can suppress autocatalytic action of the ethylene, influencing the flavor and texture changes of the apple tissue. Obtained results can be used for prediction of the life-time of studied material, corresponding to selected temperatures and different conversion levels.",
journal = "Journal of Thermal Analysis and Calorimetry",
title = "The kinetic study of juice industry residues drying process based on TGA-DTG experimental data",
doi = "10.1007/s10973-022-11289-5"
}
Milanović, M., Komatina, M., Janković, B., Stojiljković, D.,& Manić, N.. (2022). The kinetic study of juice industry residues drying process based on TGA-DTG experimental data. in Journal of Thermal Analysis and Calorimetry.
https://doi.org/10.1007/s10973-022-11289-5
Milanović M, Komatina M, Janković B, Stojiljković D, Manić N. The kinetic study of juice industry residues drying process based on TGA-DTG experimental data. in Journal of Thermal Analysis and Calorimetry. 2022;.
doi:10.1007/s10973-022-11289-5 .
Milanović, Mihailo, Komatina, Mirko, Janković, Bojan, Stojiljković, Dragoslava, Manić, Nebojša, "The kinetic study of juice industry residues drying process based on TGA-DTG experimental data" in Journal of Thermal Analysis and Calorimetry (2022),
https://doi.org/10.1007/s10973-022-11289-5 . .

The impact of production operating parameters on mechanical and thermophysical characteristics of commercial wood pellets

Manić, Nebojša G.; Janković, Bojan Ž.; Milović, Ljubica; Komatina, Mirko; Stojiljković, Dragoslava

(2021)

TY  - JOUR
AU  - Manić, Nebojša G.
AU  - Janković, Bojan Ž.
AU  - Milović, Ljubica
AU  - Komatina, Mirko
AU  - Stojiljković, Dragoslava
PY  - 2021
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9870
AB  - This study presents the experimental results of the mechanical and thermophysical properties of wood pellet samples important for their utilization in pellet stoves and boilers for heat production. The impact of operational parameters during the production process on a single pelletizer unit for three typical domestic commercial wood pellet samples (PWP110, BWP110, and BWP140) on fuel particle mechanical characteristics and related thermal properties was analyzed. It was concluded that the changes in raw material selection, as well as related operating parameters (extrusion length, i.e., die temperature during production process), have influenced the key mechanical and thermal characteristics of tested commercial wood pellets. The presented results have indicated the existence of a thin solid layer (due to waxes and subsequently lignin coating layer behaviors depending on their glass transition temperatures) on the surface of the BWP140 pellet sample. This layer leads to increasing the thermal resistance in the considered sample which can be explained by decreasing the effective thermal conductivity. Also, the forming of this layer on the surface of the wood pellet sample was caused by the production process (high-temperature impact explained by increasing friction between the die and feedstock during pellets production). It could be related to a lower value of effective thermal conductivity and specific heat capacity for considered (Beech) wood pellet sample.
T2  - Biomass Conversion and Biorefinery
T1  - The impact of production operating parameters on mechanical and thermophysical characteristics of commercial wood pellets
DO  - 10.1007/s13399-021-01609-4
ER  - 
@article{
author = "Manić, Nebojša G. and Janković, Bojan Ž. and Milović, Ljubica and Komatina, Mirko and Stojiljković, Dragoslava",
year = "2021",
abstract = "This study presents the experimental results of the mechanical and thermophysical properties of wood pellet samples important for their utilization in pellet stoves and boilers for heat production. The impact of operational parameters during the production process on a single pelletizer unit for three typical domestic commercial wood pellet samples (PWP110, BWP110, and BWP140) on fuel particle mechanical characteristics and related thermal properties was analyzed. It was concluded that the changes in raw material selection, as well as related operating parameters (extrusion length, i.e., die temperature during production process), have influenced the key mechanical and thermal characteristics of tested commercial wood pellets. The presented results have indicated the existence of a thin solid layer (due to waxes and subsequently lignin coating layer behaviors depending on their glass transition temperatures) on the surface of the BWP140 pellet sample. This layer leads to increasing the thermal resistance in the considered sample which can be explained by decreasing the effective thermal conductivity. Also, the forming of this layer on the surface of the wood pellet sample was caused by the production process (high-temperature impact explained by increasing friction between the die and feedstock during pellets production). It could be related to a lower value of effective thermal conductivity and specific heat capacity for considered (Beech) wood pellet sample.",
journal = "Biomass Conversion and Biorefinery",
title = "The impact of production operating parameters on mechanical and thermophysical characteristics of commercial wood pellets",
doi = "10.1007/s13399-021-01609-4"
}
Manić, N. G., Janković, B. Ž., Milović, L., Komatina, M.,& Stojiljković, D.. (2021). The impact of production operating parameters on mechanical and thermophysical characteristics of commercial wood pellets. in Biomass Conversion and Biorefinery.
https://doi.org/10.1007/s13399-021-01609-4
Manić NG, Janković BŽ, Milović L, Komatina M, Stojiljković D. The impact of production operating parameters on mechanical and thermophysical characteristics of commercial wood pellets. in Biomass Conversion and Biorefinery. 2021;.
doi:10.1007/s13399-021-01609-4 .
Manić, Nebojša G., Janković, Bojan Ž., Milović, Ljubica, Komatina, Mirko, Stojiljković, Dragoslava, "The impact of production operating parameters on mechanical and thermophysical characteristics of commercial wood pellets" in Biomass Conversion and Biorefinery (2021),
https://doi.org/10.1007/s13399-021-01609-4 . .
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Energy performance of single family houses in Serbia: Analysis of calculation procedures

Manić, Dimitrije; Komatina, Mirko; Vučićević, Biljana S.; Jovanović, Marina P.

(2019)

TY  - JOUR
AU  - Manić, Dimitrije
AU  - Komatina, Mirko
AU  - Vučićević, Biljana S.
AU  - Jovanović, Marina P.
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8984
AB  - Energy certification of buildings in Serbia was introduced in 2011 and energy label depends on energy need for heating per unit floor area of heated space, calculated by the fully prescribed monthly quasi-steady-state method defined by ISO 13790. In the Republic of Serbia, most of families live in single-family houses built before the energy certification of buildings was introduced. Therefore, the estimation of energy performance of the existing buildings is important for labeling, and evaluation of energy saving measures and energy strategies to be implemented. This paper examines the applicability of monthly method defined by National legislation on the existing buildings stock in Serbia, by comparing it to the more accurate dynamic simulation method. Typical single-family houses are taken as a test case, since they are responsible for about 76% of energy consumption for heating. The results show that the dynamic simulation method estimates 21% to 54% higher energy need for heating, compared to the monthly method. Also, the monthly method estimates up to 13% higher savings by typical building envelope energy saving measures, compared to the dynamic simulation. This paper recommends improvement in procedures for calculation of building energy performance index to better assess energy consumption, effects of energy saving measures, and create solid background for developing and implementing of energy saving strategies.
T2  - Thermal Science
T1  - Energy performance of single family houses in Serbia: Analysis of calculation procedures
VL  - 23
IS  - Suppl. 5
SP  - 1695
EP  - 1705
DO  - 10.2298/TSCI180726073M
ER  - 
@article{
author = "Manić, Dimitrije and Komatina, Mirko and Vučićević, Biljana S. and Jovanović, Marina P.",
year = "2019",
abstract = "Energy certification of buildings in Serbia was introduced in 2011 and energy label depends on energy need for heating per unit floor area of heated space, calculated by the fully prescribed monthly quasi-steady-state method defined by ISO 13790. In the Republic of Serbia, most of families live in single-family houses built before the energy certification of buildings was introduced. Therefore, the estimation of energy performance of the existing buildings is important for labeling, and evaluation of energy saving measures and energy strategies to be implemented. This paper examines the applicability of monthly method defined by National legislation on the existing buildings stock in Serbia, by comparing it to the more accurate dynamic simulation method. Typical single-family houses are taken as a test case, since they are responsible for about 76% of energy consumption for heating. The results show that the dynamic simulation method estimates 21% to 54% higher energy need for heating, compared to the monthly method. Also, the monthly method estimates up to 13% higher savings by typical building envelope energy saving measures, compared to the dynamic simulation. This paper recommends improvement in procedures for calculation of building energy performance index to better assess energy consumption, effects of energy saving measures, and create solid background for developing and implementing of energy saving strategies.",
journal = "Thermal Science",
title = "Energy performance of single family houses in Serbia: Analysis of calculation procedures",
volume = "23",
number = "Suppl. 5",
pages = "1695-1705",
doi = "10.2298/TSCI180726073M"
}
Manić, D., Komatina, M., Vučićević, B. S.,& Jovanović, M. P.. (2019). Energy performance of single family houses in Serbia: Analysis of calculation procedures. in Thermal Science, 23(Suppl. 5), 1695-1705.
https://doi.org/10.2298/TSCI180726073M
Manić D, Komatina M, Vučićević BS, Jovanović MP. Energy performance of single family houses in Serbia: Analysis of calculation procedures. in Thermal Science. 2019;23(Suppl. 5):1695-1705.
doi:10.2298/TSCI180726073M .
Manić, Dimitrije, Komatina, Mirko, Vučićević, Biljana S., Jovanović, Marina P., "Energy performance of single family houses in Serbia: Analysis of calculation procedures" in Thermal Science, 23, no. Suppl. 5 (2019):1695-1705,
https://doi.org/10.2298/TSCI180726073M . .

Modeling of transport processes in the cigarette principle combustion furnace

Erić, Aleksandar; Nemoda, Stevan; Komatina, Mirko; Repić, Branislav; Dakic, Dragoljub

(2019)

TY  - JOUR
AU  - Erić, Aleksandar
AU  - Nemoda, Stevan
AU  - Komatina, Mirko
AU  - Repić, Branislav
AU  - Dakic, Dragoljub
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8989
AB  - This paper presents numerical and experimental investigations of complex and interrelated physical and chemical phenomena that occur during combustion of baled soybean residue in the furnace with the cigarette type of combustion. The result of comprehensive research is reactive flow model of biomass combustion inside furnace. Model is described by set of PDE which define momentum, heat and mass transfer processes in porous and fluid system. The main aim of developed CFD model is numerical simulation of combustion process inside the cigarette furnace. It is also used to provide deeper insight in complex processes occurring during biomass combustion. Verification of proposed numerical model was performed through comprehensive experimental tests on the experimental-industrial plant of 1.5 MW boiler for heating the greenhouses in the Agricultural Corporation in Belgrade. The tests included measurement of flow rate and air and flue gas temperature input and output values on the furnace that are taken as the boundary conditions of the developed model. Comparison of the experimental results shows satisfactory agreement with numerical results (the maximum relative deviation of calculation and measurement temperatures are 10-45%), therefore the developed mathematical model could be used to analyse the effects of structural and parametric (fuel composition, power rate, air excess etc.) changes of the facility, from the standpoint of energy efficiency and ecology.
T2  - Thermal Science
T1  - Modeling of transport processes in the cigarette principle combustion furnace
VL  - 23
IS  - Suppl. 5
SP  - 1499
EP  - 1510
DO  - 10.2298/TSCI180226318E
ER  - 
@article{
author = "Erić, Aleksandar and Nemoda, Stevan and Komatina, Mirko and Repić, Branislav and Dakic, Dragoljub",
year = "2019",
abstract = "This paper presents numerical and experimental investigations of complex and interrelated physical and chemical phenomena that occur during combustion of baled soybean residue in the furnace with the cigarette type of combustion. The result of comprehensive research is reactive flow model of biomass combustion inside furnace. Model is described by set of PDE which define momentum, heat and mass transfer processes in porous and fluid system. The main aim of developed CFD model is numerical simulation of combustion process inside the cigarette furnace. It is also used to provide deeper insight in complex processes occurring during biomass combustion. Verification of proposed numerical model was performed through comprehensive experimental tests on the experimental-industrial plant of 1.5 MW boiler for heating the greenhouses in the Agricultural Corporation in Belgrade. The tests included measurement of flow rate and air and flue gas temperature input and output values on the furnace that are taken as the boundary conditions of the developed model. Comparison of the experimental results shows satisfactory agreement with numerical results (the maximum relative deviation of calculation and measurement temperatures are 10-45%), therefore the developed mathematical model could be used to analyse the effects of structural and parametric (fuel composition, power rate, air excess etc.) changes of the facility, from the standpoint of energy efficiency and ecology.",
journal = "Thermal Science",
title = "Modeling of transport processes in the cigarette principle combustion furnace",
volume = "23",
number = "Suppl. 5",
pages = "1499-1510",
doi = "10.2298/TSCI180226318E"
}
Erić, A., Nemoda, S., Komatina, M., Repić, B.,& Dakic, D.. (2019). Modeling of transport processes in the cigarette principle combustion furnace. in Thermal Science, 23(Suppl. 5), 1499-1510.
https://doi.org/10.2298/TSCI180226318E
Erić A, Nemoda S, Komatina M, Repić B, Dakic D. Modeling of transport processes in the cigarette principle combustion furnace. in Thermal Science. 2019;23(Suppl. 5):1499-1510.
doi:10.2298/TSCI180226318E .
Erić, Aleksandar, Nemoda, Stevan, Komatina, Mirko, Repić, Branislav, Dakic, Dragoljub, "Modeling of transport processes in the cigarette principle combustion furnace" in Thermal Science, 23, no. Suppl. 5 (2019):1499-1510,
https://doi.org/10.2298/TSCI180226318E . .

Euler-Euler granular flow model of the combustion of liquid fuels in a fluidized reactor

Nemoda, Stevan; Mladenović, Milica R.; Paprika, Milijana; Dakić, Dragoljub V.; Erić, Aleksandar; Komatina, Mirko

(2015)

TY  - JOUR
AU  - Nemoda, Stevan
AU  - Mladenović, Milica R.
AU  - Paprika, Milijana
AU  - Dakić, Dragoljub V.
AU  - Erić, Aleksandar
AU  - Komatina, Mirko
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/512
AB  - This paper deals with the numerical simulation of liquid fuel combustion in a fluidized reactor using two-fluid Eulerian-Eulerian fluidized bed modeling incorporating the kinetic theory of granular flow (KTGF) to gas and solid phase flow prediction. The comprehensive model of the complex processes in a fluidized combustion chamber incorporates, besides the prediction of gas and particular phase velocity fields, the energy equations for the gas and solid phase and the transport equations of conservation of chemical species with the source terms due to the conversion of chemical components. Numerical experiments showed that the coefficients in the model of inter-phase interaction drag force have a significant effect, and they have to be adjusted for each regime of fluidization. A series of numerical experiments was performed with combustion of liquid fuels in a fluidized bed (FB), with and without significant water content. The given estimations were related to the unsteady state, and the modeled period corresponds to the passing time of the flow through the reactor column. The numerical experiments were conducted to examine the impact of the water content in a liquid fuel on the global FB combustion kinetics.
T2  - Journal of the Serbian Chemical Society
T1  - Euler-Euler granular flow model of the combustion of liquid fuels in a fluidized reactor
VL  - 80
IS  - 3
SP  - 377
EP  - 389
DO  - 10.2298/JSC140130029N
ER  - 
@article{
author = "Nemoda, Stevan and Mladenović, Milica R. and Paprika, Milijana and Dakić, Dragoljub V. and Erić, Aleksandar and Komatina, Mirko",
year = "2015",
abstract = "This paper deals with the numerical simulation of liquid fuel combustion in a fluidized reactor using two-fluid Eulerian-Eulerian fluidized bed modeling incorporating the kinetic theory of granular flow (KTGF) to gas and solid phase flow prediction. The comprehensive model of the complex processes in a fluidized combustion chamber incorporates, besides the prediction of gas and particular phase velocity fields, the energy equations for the gas and solid phase and the transport equations of conservation of chemical species with the source terms due to the conversion of chemical components. Numerical experiments showed that the coefficients in the model of inter-phase interaction drag force have a significant effect, and they have to be adjusted for each regime of fluidization. A series of numerical experiments was performed with combustion of liquid fuels in a fluidized bed (FB), with and without significant water content. The given estimations were related to the unsteady state, and the modeled period corresponds to the passing time of the flow through the reactor column. The numerical experiments were conducted to examine the impact of the water content in a liquid fuel on the global FB combustion kinetics.",
journal = "Journal of the Serbian Chemical Society",
title = "Euler-Euler granular flow model of the combustion of liquid fuels in a fluidized reactor",
volume = "80",
number = "3",
pages = "377-389",
doi = "10.2298/JSC140130029N"
}
Nemoda, S., Mladenović, M. R., Paprika, M., Dakić, D. V., Erić, A.,& Komatina, M.. (2015). Euler-Euler granular flow model of the combustion of liquid fuels in a fluidized reactor. in Journal of the Serbian Chemical Society, 80(3), 377-389.
https://doi.org/10.2298/JSC140130029N
Nemoda S, Mladenović MR, Paprika M, Dakić DV, Erić A, Komatina M. Euler-Euler granular flow model of the combustion of liquid fuels in a fluidized reactor. in Journal of the Serbian Chemical Society. 2015;80(3):377-389.
doi:10.2298/JSC140130029N .
Nemoda, Stevan, Mladenović, Milica R., Paprika, Milijana, Dakić, Dragoljub V., Erić, Aleksandar, Komatina, Mirko, "Euler-Euler granular flow model of the combustion of liquid fuels in a fluidized reactor" in Journal of the Serbian Chemical Society, 80, no. 3 (2015):377-389,
https://doi.org/10.2298/JSC140130029N . .
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Experimental and Numerical Investigation of the Primary Fragmentation of a Lignite during Fluidized-Bed (FB) Devolatilization

Paprika, Milijana; Komatina, Mirko; Dakić, Dragoljub V.; Živković, Goran S.; Mladenović, Milica R.

(2015)

TY  - JOUR
AU  - Paprika, Milijana
AU  - Komatina, Mirko
AU  - Dakić, Dragoljub V.
AU  - Živković, Goran S.
AU  - Mladenović, Milica R.
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/7069
AB  - The paper presents a comparison between experimental and model results of primary fragmentation of a lignite coal in a fluidized bed (FB). In the experiments, the char particle size distribution and the general indicators of primary fragmentation (intensity and index) were determined. The same parameters were calculated using a mathematical model of the process, fed by data of the fuel (the amount of volatiles and fixed carbon), fluidized bed temperature; and inlet particle size distribution. The size distribution and number of the char particles in fluidized bed significantly differ from the size distribution and number of inlet coal particles. Char population has a bimodal distribution separate distributions for the smaller and larger sets of fragments. The experimental and model results show the same tendency: a coal particle partially breaks at the beginning of devolatilization, giving a large number of fine fragments, while, as the process continues, the rest of the parent particle sometimes breaks down into a smaller number of larger pieces, and sometimes does not fragment at all. Review of the Weibull distribution coefficients enables prediction of the char particle size distribution for the characteristic fluidized bed conditions and inlet coal particle sizes.
T2  - Energy and Fuels
T1  - Experimental and Numerical Investigation of the Primary Fragmentation of a Lignite during Fluidized-Bed (FB) Devolatilization
VL  - 29
IS  - 5
SP  - 3394
EP  - 3398
DO  - 10.1021/ef5024803
ER  - 
@article{
author = "Paprika, Milijana and Komatina, Mirko and Dakić, Dragoljub V. and Živković, Goran S. and Mladenović, Milica R.",
year = "2015",
abstract = "The paper presents a comparison between experimental and model results of primary fragmentation of a lignite coal in a fluidized bed (FB). In the experiments, the char particle size distribution and the general indicators of primary fragmentation (intensity and index) were determined. The same parameters were calculated using a mathematical model of the process, fed by data of the fuel (the amount of volatiles and fixed carbon), fluidized bed temperature; and inlet particle size distribution. The size distribution and number of the char particles in fluidized bed significantly differ from the size distribution and number of inlet coal particles. Char population has a bimodal distribution separate distributions for the smaller and larger sets of fragments. The experimental and model results show the same tendency: a coal particle partially breaks at the beginning of devolatilization, giving a large number of fine fragments, while, as the process continues, the rest of the parent particle sometimes breaks down into a smaller number of larger pieces, and sometimes does not fragment at all. Review of the Weibull distribution coefficients enables prediction of the char particle size distribution for the characteristic fluidized bed conditions and inlet coal particle sizes.",
journal = "Energy and Fuels",
title = "Experimental and Numerical Investigation of the Primary Fragmentation of a Lignite during Fluidized-Bed (FB) Devolatilization",
volume = "29",
number = "5",
pages = "3394-3398",
doi = "10.1021/ef5024803"
}
Paprika, M., Komatina, M., Dakić, D. V., Živković, G. S.,& Mladenović, M. R.. (2015). Experimental and Numerical Investigation of the Primary Fragmentation of a Lignite during Fluidized-Bed (FB) Devolatilization. in Energy and Fuels, 29(5), 3394-3398.
https://doi.org/10.1021/ef5024803
Paprika M, Komatina M, Dakić DV, Živković GS, Mladenović MR. Experimental and Numerical Investigation of the Primary Fragmentation of a Lignite during Fluidized-Bed (FB) Devolatilization. in Energy and Fuels. 2015;29(5):3394-3398.
doi:10.1021/ef5024803 .
Paprika, Milijana, Komatina, Mirko, Dakić, Dragoljub V., Živković, Goran S., Mladenović, Milica R., "Experimental and Numerical Investigation of the Primary Fragmentation of a Lignite during Fluidized-Bed (FB) Devolatilization" in Energy and Fuels, 29, no. 5 (2015):3394-3398,
https://doi.org/10.1021/ef5024803 . .
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Experimental determination thermo physical characteristics of balled biomass

Erić, Aleksandar; Dakić, Dragoljub V.; Nemoda, Stevan; Komatina, Mirko; Repić, Branislav

(2012)

TY  - JOUR
AU  - Erić, Aleksandar
AU  - Dakić, Dragoljub V.
AU  - Nemoda, Stevan
AU  - Komatina, Mirko
AU  - Repić, Branislav
PY  - 2012
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/5055
AB  - The paper presents the results of an experimental investigation conducted to determine the permeability coefficients and the stagnant thermal conductivity i.e. the thermo physical properties deemed to be the most important features of the bed material when considering combustion in pusher-type furnaces (i.e. combustion of biomass bales in cigar burners). The appropriate experimental methods have been developed and suitable experimental apparatus designed and constructed in order to determine permeability and stagnant thermal conductivity coefficient of the soybean straw bales. The experimental investigation conducted was aimed at examining the effects of relevant biomass bale parameters on the aforementioned coefficients. Based on the numerous measurements performed, correlations were obtained that are deemed highly important for optimization of the biomass bale combustion, as well as for modeling the transport phenomena occurring in the porous bed formed during biomass bales combustion in cigar burners. Data collected during the course of research investigation were used to develop a detailed CFD model of straw bales combustion in cigar burners. (C) 2012 Elsevier Ltd. All rights reserved.
T2  - Energy
T1  - Experimental determination thermo physical characteristics of balled biomass
VL  - 45
IS  - 1
SP  - 350
EP  - 357
DO  - 10.1016/j.energy.2012.02.063
ER  - 
@article{
author = "Erić, Aleksandar and Dakić, Dragoljub V. and Nemoda, Stevan and Komatina, Mirko and Repić, Branislav",
year = "2012",
abstract = "The paper presents the results of an experimental investigation conducted to determine the permeability coefficients and the stagnant thermal conductivity i.e. the thermo physical properties deemed to be the most important features of the bed material when considering combustion in pusher-type furnaces (i.e. combustion of biomass bales in cigar burners). The appropriate experimental methods have been developed and suitable experimental apparatus designed and constructed in order to determine permeability and stagnant thermal conductivity coefficient of the soybean straw bales. The experimental investigation conducted was aimed at examining the effects of relevant biomass bale parameters on the aforementioned coefficients. Based on the numerous measurements performed, correlations were obtained that are deemed highly important for optimization of the biomass bale combustion, as well as for modeling the transport phenomena occurring in the porous bed formed during biomass bales combustion in cigar burners. Data collected during the course of research investigation were used to develop a detailed CFD model of straw bales combustion in cigar burners. (C) 2012 Elsevier Ltd. All rights reserved.",
journal = "Energy",
title = "Experimental determination thermo physical characteristics of balled biomass",
volume = "45",
number = "1",
pages = "350-357",
doi = "10.1016/j.energy.2012.02.063"
}
Erić, A., Dakić, D. V., Nemoda, S., Komatina, M.,& Repić, B.. (2012). Experimental determination thermo physical characteristics of balled biomass. in Energy, 45(1), 350-357.
https://doi.org/10.1016/j.energy.2012.02.063
Erić A, Dakić DV, Nemoda S, Komatina M, Repić B. Experimental determination thermo physical characteristics of balled biomass. in Energy. 2012;45(1):350-357.
doi:10.1016/j.energy.2012.02.063 .
Erić, Aleksandar, Dakić, Dragoljub V., Nemoda, Stevan, Komatina, Mirko, Repić, Branislav, "Experimental determination thermo physical characteristics of balled biomass" in Energy, 45, no. 1 (2012):350-357,
https://doi.org/10.1016/j.energy.2012.02.063 . .
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Spectroscopic research on infrared emittance of coal ash deposits

Saljnikov, Aleksandar; Vučićević, Biljana S.; Komatina, Mirko; Gojak, Milan; Goricanec, Darko; Stevanović, Zoran

(2009)

TY  - JOUR
AU  - Saljnikov, Aleksandar
AU  - Vučićević, Biljana S.
AU  - Komatina, Mirko
AU  - Gojak, Milan
AU  - Goricanec, Darko
AU  - Stevanović, Zoran
PY  - 2009
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3805
AB  - This paper deals with thermal radiation characteristics of ash deposits on a pulverized coal combustion boiler of an electric power plant. Normal emittance spectra in the near to medium infrared (2.5-25 mu m) region and total normal emittances were measured on four kinds of ground ash deposits. Measurements were conducted in the 570-1460 K temperature range which is common for boiler furnaces, by both heating and cooling the ash samples, with the aim to study the effect of their thermal history. Dependence of emittance on wavelength, temperature and chemical composition was studied, too. Samples were tested for transparency (opacity) to verify the accuracy of results. It was determined that the thicknesses used for the ash powders are opaque for infrared radiation for thicknesses in the order of a millimeter. Tests have shown that spectral emittance increases with an increase of wavelength with a characteristic pattern common for all samples. Spectral normal emittance increases strongly with temperature at shorter wavelengths and remains high and unchanged at longer ones. Emittance spectra are not very sensitive to chemical composition of ashes especially beyond lambda approximate to 5 mu m. With an increase of temperature, total emittance of the powdered sample decreases to a minimum value around 1200 K. Further temperature rise induces an increase of total emittance due to sintering in the ash. On cooling, the emittance increases monotonically following the hysteresis. Quantitative directions for evaluating thermal radiation characteristics of ash deposits for the merits of the safety design of boiler furnaces were proposed. That comprises correlating the experimentally obtained emittance spectra with curves of simple analytical form, i.e., a continuous function of minimum emittance vs. wavelength. The proposed method can be extended to other specimens from the same furnace and used to determine correlations for thermal calculation of old and design of new furnaces - with similar geometry and combusting similar coal. The method is potentially applicable to completely different boiler furnaces combusting different coal, and the authors recommend running the tests with new deposit samples. The data will then be applicable to the thermal design of a whole new class of furnaces, having similar geometry and combusting similar coal. This is expected to greatly enhance the accuracy and precision of thermal calculation as well as the efficiency of thermal design of steam boilers. (C) 2009 Elsevier Inc. All rights reserved.
T2  - Experimental Thermal and Fluid Science
T1  - Spectroscopic research on infrared emittance of coal ash deposits
VL  - 33
IS  - 8
SP  - 1133
EP  - 1141
DO  - 10.1016/j.expthermflusci.2009.07.002
ER  - 
@article{
author = "Saljnikov, Aleksandar and Vučićević, Biljana S. and Komatina, Mirko and Gojak, Milan and Goricanec, Darko and Stevanović, Zoran",
year = "2009",
abstract = "This paper deals with thermal radiation characteristics of ash deposits on a pulverized coal combustion boiler of an electric power plant. Normal emittance spectra in the near to medium infrared (2.5-25 mu m) region and total normal emittances were measured on four kinds of ground ash deposits. Measurements were conducted in the 570-1460 K temperature range which is common for boiler furnaces, by both heating and cooling the ash samples, with the aim to study the effect of their thermal history. Dependence of emittance on wavelength, temperature and chemical composition was studied, too. Samples were tested for transparency (opacity) to verify the accuracy of results. It was determined that the thicknesses used for the ash powders are opaque for infrared radiation for thicknesses in the order of a millimeter. Tests have shown that spectral emittance increases with an increase of wavelength with a characteristic pattern common for all samples. Spectral normal emittance increases strongly with temperature at shorter wavelengths and remains high and unchanged at longer ones. Emittance spectra are not very sensitive to chemical composition of ashes especially beyond lambda approximate to 5 mu m. With an increase of temperature, total emittance of the powdered sample decreases to a minimum value around 1200 K. Further temperature rise induces an increase of total emittance due to sintering in the ash. On cooling, the emittance increases monotonically following the hysteresis. Quantitative directions for evaluating thermal radiation characteristics of ash deposits for the merits of the safety design of boiler furnaces were proposed. That comprises correlating the experimentally obtained emittance spectra with curves of simple analytical form, i.e., a continuous function of minimum emittance vs. wavelength. The proposed method can be extended to other specimens from the same furnace and used to determine correlations for thermal calculation of old and design of new furnaces - with similar geometry and combusting similar coal. The method is potentially applicable to completely different boiler furnaces combusting different coal, and the authors recommend running the tests with new deposit samples. The data will then be applicable to the thermal design of a whole new class of furnaces, having similar geometry and combusting similar coal. This is expected to greatly enhance the accuracy and precision of thermal calculation as well as the efficiency of thermal design of steam boilers. (C) 2009 Elsevier Inc. All rights reserved.",
journal = "Experimental Thermal and Fluid Science",
title = "Spectroscopic research on infrared emittance of coal ash deposits",
volume = "33",
number = "8",
pages = "1133-1141",
doi = "10.1016/j.expthermflusci.2009.07.002"
}
Saljnikov, A., Vučićević, B. S., Komatina, M., Gojak, M., Goricanec, D.,& Stevanović, Z.. (2009). Spectroscopic research on infrared emittance of coal ash deposits. in Experimental Thermal and Fluid Science, 33(8), 1133-1141.
https://doi.org/10.1016/j.expthermflusci.2009.07.002
Saljnikov A, Vučićević BS, Komatina M, Gojak M, Goricanec D, Stevanović Z. Spectroscopic research on infrared emittance of coal ash deposits. in Experimental Thermal and Fluid Science. 2009;33(8):1133-1141.
doi:10.1016/j.expthermflusci.2009.07.002 .
Saljnikov, Aleksandar, Vučićević, Biljana S., Komatina, Mirko, Gojak, Milan, Goricanec, Darko, Stevanović, Zoran, "Spectroscopic research on infrared emittance of coal ash deposits" in Experimental Thermal and Fluid Science, 33, no. 8 (2009):1133-1141,
https://doi.org/10.1016/j.expthermflusci.2009.07.002 . .
9
11
15

Modeling the temperature in coal char particle during fluidized bed combustion

Manovic, Vasilije; Komatina, Mirko; Oka, Simeon N.

(2008)

TY  - JOUR
AU  - Manovic, Vasilije
AU  - Komatina, Mirko
AU  - Oka, Simeon N.
PY  - 2008
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3379
AB  - The temperatures of a coal char particle in hot bubbling fluidized bed (FB) were analyzed by a model of combustion. The unsteady model includes phenomena of heat and mass transfer through a porous char particle, as well as heterogeneous reaction at the interior char surface and homogeneous reaction in the pores. The parametric analysis of the model has shown that above 550 degrees C combustion occurs under the regime limited by diffusion. The experimental results of temperature measurements by thermocouple in the particle center during FB combustion at temperatures in the range 590-710 degrees C were compared with the model predictions. Two coals of different rank were used: lignite and brown coal, with particle size in the range 5-10 mm. The comparisons have shown that the model can adequately predict the histories of temperatures in char particles during combustion in FB. In the first order, the model predicts the influence of the particle size, coal rank (via porosity), and oxygen concentration in its surroundings. (C) 2007 Elsevier Ltd. All rights reserved.
T2  - Fuel
T1  - Modeling the temperature in coal char particle during fluidized bed combustion
VL  - 87
IS  - 6
SP  - 905
EP  - 914
DO  - 10.1016/j.fuel.2007.05.020
ER  - 
@article{
author = "Manovic, Vasilije and Komatina, Mirko and Oka, Simeon N.",
year = "2008",
abstract = "The temperatures of a coal char particle in hot bubbling fluidized bed (FB) were analyzed by a model of combustion. The unsteady model includes phenomena of heat and mass transfer through a porous char particle, as well as heterogeneous reaction at the interior char surface and homogeneous reaction in the pores. The parametric analysis of the model has shown that above 550 degrees C combustion occurs under the regime limited by diffusion. The experimental results of temperature measurements by thermocouple in the particle center during FB combustion at temperatures in the range 590-710 degrees C were compared with the model predictions. Two coals of different rank were used: lignite and brown coal, with particle size in the range 5-10 mm. The comparisons have shown that the model can adequately predict the histories of temperatures in char particles during combustion in FB. In the first order, the model predicts the influence of the particle size, coal rank (via porosity), and oxygen concentration in its surroundings. (C) 2007 Elsevier Ltd. All rights reserved.",
journal = "Fuel",
title = "Modeling the temperature in coal char particle during fluidized bed combustion",
volume = "87",
number = "6",
pages = "905-914",
doi = "10.1016/j.fuel.2007.05.020"
}
Manovic, V., Komatina, M.,& Oka, S. N.. (2008). Modeling the temperature in coal char particle during fluidized bed combustion. in Fuel, 87(6), 905-914.
https://doi.org/10.1016/j.fuel.2007.05.020
Manovic V, Komatina M, Oka SN. Modeling the temperature in coal char particle during fluidized bed combustion. in Fuel. 2008;87(6):905-914.
doi:10.1016/j.fuel.2007.05.020 .
Manovic, Vasilije, Komatina, Mirko, Oka, Simeon N., "Modeling the temperature in coal char particle during fluidized bed combustion" in Fuel, 87, no. 6 (2008):905-914,
https://doi.org/10.1016/j.fuel.2007.05.020 . .
19
18
18

Effects of air excess control in a heat storage solid fuel-fired household furnace

Mladenovic, Rastko; Belošević, Srđan; Paprika, Milijana; Komatina, Mirko; Dakić, Dragoljub V.; Erić, Aleksandar; Đurović, Dejan M.

(2007)

TY  - JOUR
AU  - Mladenovic, Rastko
AU  - Belošević, Srđan
AU  - Paprika, Milijana
AU  - Komatina, Mirko
AU  - Dakić, Dragoljub V.
AU  - Erić, Aleksandar
AU  - Đurović, Dejan M.
PY  - 2007
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3209
AB  - Due to a significant increase in electricity prices during the last decade and insufficient production capacity of the electric power industry in Serbia, many households that are currently using electric heat storage furnaces for heating have been forced to find an alternative solution for heating. A possible solution is replacing electric heating appliances with similar solid fuel-fired ones. Existing solid fuel-fired furnaces are often unsatisfactory with respect to their efficiencies and flue gas emissions. A prototype of a new concept of heat storage, solid fuel-fired furnace has been developed to meet these growing needs, providing electricity saving together with considerable environmental benefits. In order to examine furnace performance, efficiency and environmental aspects, and to assess the influence of air excess control in the furnace on the efficiency and flue gas emissions, numerous experimental tests were conducted. The amount of combustion air, the flue gas flow rate and the fuel feeding regime have been adjusted in order to keep the flue gas oxygen content in a relatively narrow range, thus obtaining controlled combustion conditions and, correspondingly, lower carbon monoxide emission and higher furnace efficiency. In this way, the furnace was made able to respond to the changes in heating needs, fuel quality and other parameters, which is considered to be advantageous in comparison with similar solid-fuel fired furnaces. (c) 2007 Elsevier Ltd. All rights reserved.
T2  - Applied Thermal Engineering
T1  - Effects of air excess control in a heat storage solid fuel-fired household furnace
VL  - 27
IS  - 13
SP  - 2243
EP  - 2251
DO  - 10.1016/j.applthermaleng.2007.01.016
ER  - 
@article{
author = "Mladenovic, Rastko and Belošević, Srđan and Paprika, Milijana and Komatina, Mirko and Dakić, Dragoljub V. and Erić, Aleksandar and Đurović, Dejan M.",
year = "2007",
abstract = "Due to a significant increase in electricity prices during the last decade and insufficient production capacity of the electric power industry in Serbia, many households that are currently using electric heat storage furnaces for heating have been forced to find an alternative solution for heating. A possible solution is replacing electric heating appliances with similar solid fuel-fired ones. Existing solid fuel-fired furnaces are often unsatisfactory with respect to their efficiencies and flue gas emissions. A prototype of a new concept of heat storage, solid fuel-fired furnace has been developed to meet these growing needs, providing electricity saving together with considerable environmental benefits. In order to examine furnace performance, efficiency and environmental aspects, and to assess the influence of air excess control in the furnace on the efficiency and flue gas emissions, numerous experimental tests were conducted. The amount of combustion air, the flue gas flow rate and the fuel feeding regime have been adjusted in order to keep the flue gas oxygen content in a relatively narrow range, thus obtaining controlled combustion conditions and, correspondingly, lower carbon monoxide emission and higher furnace efficiency. In this way, the furnace was made able to respond to the changes in heating needs, fuel quality and other parameters, which is considered to be advantageous in comparison with similar solid-fuel fired furnaces. (c) 2007 Elsevier Ltd. All rights reserved.",
journal = "Applied Thermal Engineering",
title = "Effects of air excess control in a heat storage solid fuel-fired household furnace",
volume = "27",
number = "13",
pages = "2243-2251",
doi = "10.1016/j.applthermaleng.2007.01.016"
}
Mladenovic, R., Belošević, S., Paprika, M., Komatina, M., Dakić, D. V., Erić, A.,& Đurović, D. M.. (2007). Effects of air excess control in a heat storage solid fuel-fired household furnace. in Applied Thermal Engineering, 27(13), 2243-2251.
https://doi.org/10.1016/j.applthermaleng.2007.01.016
Mladenovic R, Belošević S, Paprika M, Komatina M, Dakić DV, Erić A, Đurović DM. Effects of air excess control in a heat storage solid fuel-fired household furnace. in Applied Thermal Engineering. 2007;27(13):2243-2251.
doi:10.1016/j.applthermaleng.2007.01.016 .
Mladenovic, Rastko, Belošević, Srđan, Paprika, Milijana, Komatina, Mirko, Dakić, Dragoljub V., Erić, Aleksandar, Đurović, Dejan M., "Effects of air excess control in a heat storage solid fuel-fired household furnace" in Applied Thermal Engineering, 27, no. 13 (2007):2243-2251,
https://doi.org/10.1016/j.applthermaleng.2007.01.016 . .
3
2
4

Properties and efficiency of a Pt/Al2O3 catalyst applied in a solid fuel thermo-accumulating furnace

Belošević, Srđan; Mladenovic, Rastko; Dakić, Dragoljub V.; Paprika, Milijana; Erić, Aleksandar; Đurović, Dejan M.; Komatina, Mirko; Grbic, Bosko; Radic, Nenad

(2007)

TY  - JOUR
AU  - Belošević, Srđan
AU  - Mladenovic, Rastko
AU  - Dakić, Dragoljub V.
AU  - Paprika, Milijana
AU  - Erić, Aleksandar
AU  - Đurović, Dejan M.
AU  - Komatina, Mirko
AU  - Grbic, Bosko
AU  - Radic, Nenad
PY  - 2007
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3287
AB  - A prototype of a solid fuel thermo-accumulating furnace has been developed. In order to achieve a higher combustion efficiency, a Pt/Al2O3 catalyst in the form of 3 +/- 0.3 mm spheres was applied, which enabled further combustion of flue gases within the furnace. Experimental investigation of the influence of the catalyst on the conversion of CO has been done for different operation regimes and positions of the catalyst. Paper presents selected results regarding CO emission during wood and coal combustion. Investigations suggest a considerable effect of the catalyst and a strong influence of the catalyst position to CO emission reduction. The microstructure of the catalyst beads, characterized by selective chemisorption of CO, has shown the decrease of the number of Pt sites as a consequence of block-age by coke deposits formed during the combustion of solid fuel.
T2  - Journal of the Serbian Chemical Society
T1  - Properties and efficiency of a Pt/Al2O3 catalyst applied in a solid fuel thermo-accumulating furnace
VL  - 72
IS  - 8-9
SP  - 869
EP  - 878
DO  - 10.2298/JSC0709869B
ER  - 
@article{
author = "Belošević, Srđan and Mladenovic, Rastko and Dakić, Dragoljub V. and Paprika, Milijana and Erić, Aleksandar and Đurović, Dejan M. and Komatina, Mirko and Grbic, Bosko and Radic, Nenad",
year = "2007",
abstract = "A prototype of a solid fuel thermo-accumulating furnace has been developed. In order to achieve a higher combustion efficiency, a Pt/Al2O3 catalyst in the form of 3 +/- 0.3 mm spheres was applied, which enabled further combustion of flue gases within the furnace. Experimental investigation of the influence of the catalyst on the conversion of CO has been done for different operation regimes and positions of the catalyst. Paper presents selected results regarding CO emission during wood and coal combustion. Investigations suggest a considerable effect of the catalyst and a strong influence of the catalyst position to CO emission reduction. The microstructure of the catalyst beads, characterized by selective chemisorption of CO, has shown the decrease of the number of Pt sites as a consequence of block-age by coke deposits formed during the combustion of solid fuel.",
journal = "Journal of the Serbian Chemical Society",
title = "Properties and efficiency of a Pt/Al2O3 catalyst applied in a solid fuel thermo-accumulating furnace",
volume = "72",
number = "8-9",
pages = "869-878",
doi = "10.2298/JSC0709869B"
}
Belošević, S., Mladenovic, R., Dakić, D. V., Paprika, M., Erić, A., Đurović, D. M., Komatina, M., Grbic, B.,& Radic, N.. (2007). Properties and efficiency of a Pt/Al2O3 catalyst applied in a solid fuel thermo-accumulating furnace. in Journal of the Serbian Chemical Society, 72(8-9), 869-878.
https://doi.org/10.2298/JSC0709869B
Belošević S, Mladenovic R, Dakić DV, Paprika M, Erić A, Đurović DM, Komatina M, Grbic B, Radic N. Properties and efficiency of a Pt/Al2O3 catalyst applied in a solid fuel thermo-accumulating furnace. in Journal of the Serbian Chemical Society. 2007;72(8-9):869-878.
doi:10.2298/JSC0709869B .
Belošević, Srđan, Mladenovic, Rastko, Dakić, Dragoljub V., Paprika, Milijana, Erić, Aleksandar, Đurović, Dejan M., Komatina, Mirko, Grbic, Bosko, Radic, Nenad, "Properties and efficiency of a Pt/Al2O3 catalyst applied in a solid fuel thermo-accumulating furnace" in Journal of the Serbian Chemical Society, 72, no. 8-9 (2007):869-878,
https://doi.org/10.2298/JSC0709869B . .