TY  - JOUR
AU  - Mladenović, Milica R.
AU  - Mladenovic, Rastko
AU  - Manovic, Vasilije
AU  - Radovanović, Milan
AU  - Stojiljković, Dragoslava
PY  - 2009
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/3860
AB  - Based on investigations of ash deposit formation, semi-empirical indicators for slagging and fouling, based on ash chemical composition and its fusion temperature, have been determined These criteria-indicators, in suggested limits, describe the coals on which they are based (North-American and British) well. However, the experience in the thermal power production sector of Serbia shows that their literal application to domestic coals does not produce satisfactory results. This contribution provides an analysis of applicability and the choice of criteria that are suitable for Serbian coals. The focus of the contribution is on coal slagging indicators, since slagging has much heavier consequences on heat transfer inside the steam boiler, and on boiler operation as a whole. The basis for the analysis of chosen criteria comprises of the results of investigations of four coalfields - Kostolac, Kolubara, Kosovo (Serbia), and Ugljevik (Bosnia and Herzegovina).
T2  - Thermal Science
T1  - Criteria Selection for the Assessment of Serbian Lignites Tendency to Form Deposits on Power Boilers Heat Transfer Surfaces
VL  - 13
IS  - 4
SP  - 61
EP  - 78
DO  - 10.2298/TSCI0904061M
ER  - 

@article{
author = "Mladenović, Milica R. and Mladenovic, Rastko and Manovic, Vasilije and Radovanović, Milan and Stojiljković, Dragoslava",
year = "2009",
abstract = "Based on investigations of ash deposit formation, semi-empirical indicators for slagging and fouling, based on ash chemical composition and its fusion temperature, have been determined These criteria-indicators, in suggested limits, describe the coals on which they are based (North-American and British) well. However, the experience in the thermal power production sector of Serbia shows that their literal application to domestic coals does not produce satisfactory results. This contribution provides an analysis of applicability and the choice of criteria that are suitable for Serbian coals. The focus of the contribution is on coal slagging indicators, since slagging has much heavier consequences on heat transfer inside the steam boiler, and on boiler operation as a whole. The basis for the analysis of chosen criteria comprises of the results of investigations of four coalfields - Kostolac, Kolubara, Kosovo (Serbia), and Ugljevik (Bosnia and Herzegovina).",
journal = "Thermal Science",
title = "Criteria Selection for the Assessment of Serbian Lignites Tendency to Form Deposits on Power Boilers Heat Transfer Surfaces",
volume = "13",
number = "4",
pages = "61-78",
doi = "10.2298/TSCI0904061M"
}

Mladenović, M. R., Mladenovic, R., Manovic, V., Radovanović, M.,& Stojiljković, D.. (2009). Criteria Selection for the Assessment of Serbian Lignites Tendency to Form Deposits on Power Boilers Heat Transfer Surfaces. in Thermal Science, 13(4), 61-78.
https://doi.org/10.2298/TSCI0904061M

Mladenović MR, Mladenovic R, Manovic V, Radovanović M, Stojiljković D. Criteria Selection for the Assessment of Serbian Lignites Tendency to Form Deposits on Power Boilers Heat Transfer Surfaces. in Thermal Science. 2009;13(4):61-78.
doi:10.2298/TSCI0904061M .

Mladenović, Milica R., Mladenovic, Rastko, Manovic, Vasilije, Radovanović, Milan, Stojiljković, Dragoslava, "Criteria Selection for the Assessment of Serbian Lignites Tendency to Form Deposits on Power Boilers Heat Transfer Surfaces" in Thermal Science, 13, no. 4 (2009):61-78,
https://doi.org/10.2298/TSCI0904061M . .

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 . .

TY  - JOUR
AU  - Manovic, V
AU  - Grubor, Borislav
AU  - Lončarević, Davor
PY  - 2006
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2973
AB  - The process of inherent sulfur capture in coal particles during combustion in fluidized bed was modeled. The significance of the process is in fact that a part of sulfur may be retained in ash, decreasing emission of sulfur oxides. The process, which is also known as sulfur self-retention, is influenced by parameters that depend on coal characteristics and combustion conditions. The interest for this process was increased with the introduction of fluidized bed combustion technology because of its favorable temperatures and other conditions. The presented model is based on a model of porous char particles combustion under fluidized bed conditions, and the changing grain size model of sulfation of the CaO grains dispersed throughout the char particle volume. The phenomena of sintering, reduction of the produced CaSO4 with CO and thermal decomposition of the produced CaSO4 were incorporated in the model, allowing for the different reactivities of various forms of calcium. A temperature-dependent relation for the CaO grain radius takes sintering into account. Reductive and thermal decomposition were taken into account by the corresponding reaction rate constants of the Arrhenius type. The reactivity of the calcium forms in coal was considered by different initial radius of the CaO grains. A comprehensive parametric analysis of the model was done. The model was verified by the experimental results for three low-rank Serbian coals. Samples of different particle size (4.0-7.0, 7.0-10.0 and 10.0-13.0 mm) for each coal were combusted under fluidized bed conditions at three temperatures: 750, 800 and 850 degrees C. The maximal values of inherent sulfur capture at 800 degrees C were obtained. The comparison with the experimentally obtained results showed that the model can adequately predict the levels of the obtained values of sulfur self-retention efficiencies, as well as the influence of temperature, coal type and coal particle size. (c) 2005 Elsevier Ltd. All rights reserved.
T2  - Chemical Engineering Science
T1  - Modeling of inherent SO2 capture in coal particles during combustion in fluidized bed
VL  - 61
IS  - 5
SP  - 1676
EP  - 1685
DO  - 10.1016/j.ces.2005.10.003
ER  - 

@article{
author = "Manovic, V and Grubor, Borislav and Lončarević, Davor",
year = "2006",
abstract = "The process of inherent sulfur capture in coal particles during combustion in fluidized bed was modeled. The significance of the process is in fact that a part of sulfur may be retained in ash, decreasing emission of sulfur oxides. The process, which is also known as sulfur self-retention, is influenced by parameters that depend on coal characteristics and combustion conditions. The interest for this process was increased with the introduction of fluidized bed combustion technology because of its favorable temperatures and other conditions. The presented model is based on a model of porous char particles combustion under fluidized bed conditions, and the changing grain size model of sulfation of the CaO grains dispersed throughout the char particle volume. The phenomena of sintering, reduction of the produced CaSO4 with CO and thermal decomposition of the produced CaSO4 were incorporated in the model, allowing for the different reactivities of various forms of calcium. A temperature-dependent relation for the CaO grain radius takes sintering into account. Reductive and thermal decomposition were taken into account by the corresponding reaction rate constants of the Arrhenius type. The reactivity of the calcium forms in coal was considered by different initial radius of the CaO grains. A comprehensive parametric analysis of the model was done. The model was verified by the experimental results for three low-rank Serbian coals. Samples of different particle size (4.0-7.0, 7.0-10.0 and 10.0-13.0 mm) for each coal were combusted under fluidized bed conditions at three temperatures: 750, 800 and 850 degrees C. The maximal values of inherent sulfur capture at 800 degrees C were obtained. The comparison with the experimentally obtained results showed that the model can adequately predict the levels of the obtained values of sulfur self-retention efficiencies, as well as the influence of temperature, coal type and coal particle size. (c) 2005 Elsevier Ltd. All rights reserved.",
journal = "Chemical Engineering Science",
title = "Modeling of inherent SO2 capture in coal particles during combustion in fluidized bed",
volume = "61",
number = "5",
pages = "1676-1685",
doi = "10.1016/j.ces.2005.10.003"
}

Manovic, V., Grubor, B.,& Lončarević, D.. (2006). Modeling of inherent SO2 capture in coal particles during combustion in fluidized bed. in Chemical Engineering Science, 61(5), 1676-1685.
https://doi.org/10.1016/j.ces.2005.10.003

Manovic V, Grubor B, Lončarević D. Modeling of inherent SO2 capture in coal particles during combustion in fluidized bed. in Chemical Engineering Science. 2006;61(5):1676-1685.
doi:10.1016/j.ces.2005.10.003 .

Manovic, V, Grubor, Borislav, Lončarević, Davor, "Modeling of inherent SO2 capture in coal particles during combustion in fluidized bed" in Chemical Engineering Science, 61, no. 5 (2006):1676-1685,
https://doi.org/10.1016/j.ces.2005.10.003 . .

TY  - JOUR
AU  - Komatina, M
AU  - Manovic, V
AU  - Dakić, Dragoljub V.
PY  - 2006
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2566
AB  - The purpose of this study was to investigate the temperature of coal particle during combustion in fluidized bed (FB). It is necessary to know the coal particle temperature in order to predict kinetics of chemical reactions within and at the surface of coal particle, accurate NOx and SO2 emission, fragmentation, attrition, the possibility of ash melting, etc. The experimental investigations were conducted in order to obtain the reliable data on the temperature of particle burning in the FB. A method using thermocouple was developed and applied for measurements. Thermocouple was inserted in the center of the particle shaped into spherical form with various diameters: 5, 7, 8, and 10 rum. Two characteristic types of low-rank Serbian coals were investigated. Experiments were done at the FB temperature in the range of 590-710 degrees C. Two types of experiments were performed: (i) combustion using air as fluidization gas and (ii) devolatilization with N-2 followed by combustion of obtained char in air. The temperature histories of particles during all stages after introducing in the FB were analyzed. Temperature difference between the burning particle and the 1713 was defined as a criterion, for comparison. It was shown that the temperature profile depends on the type of the coal and the particle size. The higher temperature difference between the burning particle and the FB was obtained for smaller particles and for lignite (130-180 degrees C) in comparison to the brown coal (70-130 degrees C). The obtained results indicated that a primary role in the temperature history of coal particle have the mass and heat transfer through combusting particle.
T2  - Energy and Fuels
T1  - An experimental study of temperature of burning coal particle in fluidized bed
VL  - 20
IS  - 1
SP  - 114
EP  - 119
DO  - 10.1021/ef050222o
ER  - 

@article{
author = "Komatina, M and Manovic, V and Dakić, Dragoljub V.",
year = "2006",
abstract = "The purpose of this study was to investigate the temperature of coal particle during combustion in fluidized bed (FB). It is necessary to know the coal particle temperature in order to predict kinetics of chemical reactions within and at the surface of coal particle, accurate NOx and SO2 emission, fragmentation, attrition, the possibility of ash melting, etc. The experimental investigations were conducted in order to obtain the reliable data on the temperature of particle burning in the FB. A method using thermocouple was developed and applied for measurements. Thermocouple was inserted in the center of the particle shaped into spherical form with various diameters: 5, 7, 8, and 10 rum. Two characteristic types of low-rank Serbian coals were investigated. Experiments were done at the FB temperature in the range of 590-710 degrees C. Two types of experiments were performed: (i) combustion using air as fluidization gas and (ii) devolatilization with N-2 followed by combustion of obtained char in air. The temperature histories of particles during all stages after introducing in the FB were analyzed. Temperature difference between the burning particle and the 1713 was defined as a criterion, for comparison. It was shown that the temperature profile depends on the type of the coal and the particle size. The higher temperature difference between the burning particle and the FB was obtained for smaller particles and for lignite (130-180 degrees C) in comparison to the brown coal (70-130 degrees C). The obtained results indicated that a primary role in the temperature history of coal particle have the mass and heat transfer through combusting particle.",
journal = "Energy and Fuels",
title = "An experimental study of temperature of burning coal particle in fluidized bed",
volume = "20",
number = "1",
pages = "114-119",
doi = "10.1021/ef050222o"
}

Komatina, M., Manovic, V.,& Dakić, D. V.. (2006). An experimental study of temperature of burning coal particle in fluidized bed. in Energy and Fuels, 20(1), 114-119.
https://doi.org/10.1021/ef050222o

Komatina M, Manovic V, Dakić DV. An experimental study of temperature of burning coal particle in fluidized bed. in Energy and Fuels. 2006;20(1):114-119.
doi:10.1021/ef050222o .

Komatina, M, Manovic, V, Dakić, Dragoljub V., "An experimental study of temperature of burning coal particle in fluidized bed" in Energy and Fuels, 20, no. 1 (2006):114-119,
https://doi.org/10.1021/ef050222o . .

TY  - JOUR
AU  - Manovic, V
AU  - Grubor, Borislav
PY  - 2006
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2567
AB  - The overall process of coal combustion takes place in two successive steps: devolatilization and char combustion. The fate of sulfur during the devolatilization of coal of different rank was investigated. The significance of the investigation is in fact that a major part of sulfur release occurs during devolatilization of coal, (i.e., emission of sulfur oxides during combustion of coal largely depends on sulfur release during devolatilization). The experimental investigations were conducted to obtain the data about the quantitative relation between sulfur content in the coal and sulfur content in the char. Standard procedures were used for obtaining the chars in a laboratory oven and determining the sulfur forms in the coal and char samples. The experiments were done with grounded coal samples ( LT 0.2 mm), at the temperatures in the range of 500-1000 degrees C. We showed that the amount of sulfur remaining in the char decreases, but not significantly in the temperature range 600-900 degrees C. On the basis of the theoretical consideration of behavior of sulfur forms during devolatilization, certain simplifying assumptions, and obtained experimental data, we propose two correlations to associate the content of sulfur in the coal and in the char. The correlations are based on the results of the proximate analysis and sulfur forms in coal. Good agreement was found when the proposed correlations were compared with the experimental results obtained for investigated coals. Moreover, the correlations were verified by results found in the literature for numerous Polish, Albanian, and Turkish coals. Significant correlations (P LT 0.05) between observed and calculated data with correlation coefficient, R GT 0.9, were noticed in the case of all coals.
T2  - Energy and Fuels
T1  - Correlation for the total sulfur content in char after devolatilization
VL  - 20
IS  - 1
SP  - 133
EP  - 137
DO  - 10.1021/ef050244a
ER  - 

@article{
author = "Manovic, V and Grubor, Borislav",
year = "2006",
abstract = "The overall process of coal combustion takes place in two successive steps: devolatilization and char combustion. The fate of sulfur during the devolatilization of coal of different rank was investigated. The significance of the investigation is in fact that a major part of sulfur release occurs during devolatilization of coal, (i.e., emission of sulfur oxides during combustion of coal largely depends on sulfur release during devolatilization). The experimental investigations were conducted to obtain the data about the quantitative relation between sulfur content in the coal and sulfur content in the char. Standard procedures were used for obtaining the chars in a laboratory oven and determining the sulfur forms in the coal and char samples. The experiments were done with grounded coal samples ( LT 0.2 mm), at the temperatures in the range of 500-1000 degrees C. We showed that the amount of sulfur remaining in the char decreases, but not significantly in the temperature range 600-900 degrees C. On the basis of the theoretical consideration of behavior of sulfur forms during devolatilization, certain simplifying assumptions, and obtained experimental data, we propose two correlations to associate the content of sulfur in the coal and in the char. The correlations are based on the results of the proximate analysis and sulfur forms in coal. Good agreement was found when the proposed correlations were compared with the experimental results obtained for investigated coals. Moreover, the correlations were verified by results found in the literature for numerous Polish, Albanian, and Turkish coals. Significant correlations (P LT 0.05) between observed and calculated data with correlation coefficient, R GT 0.9, were noticed in the case of all coals.",
journal = "Energy and Fuels",
title = "Correlation for the total sulfur content in char after devolatilization",
volume = "20",
number = "1",
pages = "133-137",
doi = "10.1021/ef050244a"
}

Manovic, V.,& Grubor, B.. (2006). Correlation for the total sulfur content in char after devolatilization. in Energy and Fuels, 20(1), 133-137.
https://doi.org/10.1021/ef050244a

Manovic V, Grubor B. Correlation for the total sulfur content in char after devolatilization. in Energy and Fuels. 2006;20(1):133-137.
doi:10.1021/ef050244a .

Manovic, V, Grubor, Borislav, "Correlation for the total sulfur content in char after devolatilization" in Energy and Fuels, 20, no. 1 (2006):133-137,
https://doi.org/10.1021/ef050244a . .

TY  - CONF
AU  - Oka, Simeon N.
AU  - Grubor, Borislav
AU  - Dakić, Dragoljub V.
AU  - Ilic, M.
AU  - Manovic, V.
AU  - Erić, Milić D.
AU  - Paprika, Milijana
AU  - Oka, Nikola
AU  - Belošević, Srđan
AU  - Mladenovic, R.
AU  - Crnomarković, Nenad Đ.
PY  - 2005
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/6638
AB  - The results of the detailed investigations of behavior of lignites Kolubara and Kovin, in fluidized bed combustion are presented in the paper. Investigation was carried out due to the interest of the Serbian Electric Power Production Company to use CFBC boilers in the process of refurbishment of old pulverized coal combustion boilers. As a part of a feasibility study for CFBC use in power plants in Serbia, investigation of combustion characteristics of lignites was performed using original methodology introduced many years ago by Laboratory for Thermal Engineering and Energy. Methodology was approved by numerous investigations of more than 20 Yugoslav coals for FBC combustion, with the aim to determine design data for bubbling FBC boilers. The main attention in present investigation was paid to the problem of using methodology developed for bubbling FBC in the conditions present in CFBC boilers. Four samples of Kolubara lignite, with heat capacity from 2.5 to 8.5 MJ/kg, and different ash contents were investigated, and also lignite Kovin in the same range of heat capacity. Investigations were performed in three phases: (1) ultimate and proximate analysis, determination of ash sintering temperature by standard method and in fluidized bed laboratory oven, (2) investigations in laboratory fluidized bed furnace and determination of coal particle fragmentation, burning rate, start-up temperature and self-sulfure-capture and (3) investigation of combustion in pilot-plant in stationary combustion conditions. In conclusion, suitability of results obtained in BFBC conditions is approved, and earlier statement that lignites are suitable for BFBC is confirmed by the statement that lignites are even more suitable for burning in CFBC boilers. Considering differences between combustion and flow conditions in bubbling and circulating FBC boilers, behavior of the lignites in CFBC is discussed in details and optimal regime parameters of the CFBC boilers are determined. The results obtained will be used by Serbian Electric Power Production Company for evaluation of bid for CFBC boiler implementation in refurbishment of old thermal power plants.
T1  - Investigation of the suitability of Serbian lignites for burning in CFBC boilers
SP  - 13
EP  - 25
UR  - https://hdl.handle.net/21.15107/rcub_vinar_6638
ER  - 

@conference{
author = "Oka, Simeon N. and Grubor, Borislav and Dakić, Dragoljub V. and Ilic, M. and Manovic, V. and Erić, Milić D. and Paprika, Milijana and Oka, Nikola and Belošević, Srđan and Mladenovic, R. and Crnomarković, Nenad Đ.",
year = "2005",
abstract = "The results of the detailed investigations of behavior of lignites Kolubara and Kovin, in fluidized bed combustion are presented in the paper. Investigation was carried out due to the interest of the Serbian Electric Power Production Company to use CFBC boilers in the process of refurbishment of old pulverized coal combustion boilers. As a part of a feasibility study for CFBC use in power plants in Serbia, investigation of combustion characteristics of lignites was performed using original methodology introduced many years ago by Laboratory for Thermal Engineering and Energy. Methodology was approved by numerous investigations of more than 20 Yugoslav coals for FBC combustion, with the aim to determine design data for bubbling FBC boilers. The main attention in present investigation was paid to the problem of using methodology developed for bubbling FBC in the conditions present in CFBC boilers. Four samples of Kolubara lignite, with heat capacity from 2.5 to 8.5 MJ/kg, and different ash contents were investigated, and also lignite Kovin in the same range of heat capacity. Investigations were performed in three phases: (1) ultimate and proximate analysis, determination of ash sintering temperature by standard method and in fluidized bed laboratory oven, (2) investigations in laboratory fluidized bed furnace and determination of coal particle fragmentation, burning rate, start-up temperature and self-sulfure-capture and (3) investigation of combustion in pilot-plant in stationary combustion conditions. In conclusion, suitability of results obtained in BFBC conditions is approved, and earlier statement that lignites are suitable for BFBC is confirmed by the statement that lignites are even more suitable for burning in CFBC boilers. Considering differences between combustion and flow conditions in bubbling and circulating FBC boilers, behavior of the lignites in CFBC is discussed in details and optimal regime parameters of the CFBC boilers are determined. The results obtained will be used by Serbian Electric Power Production Company for evaluation of bid for CFBC boiler implementation in refurbishment of old thermal power plants.",
title = "Investigation of the suitability of Serbian lignites for burning in CFBC boilers",
pages = "13-25",
url = "https://hdl.handle.net/21.15107/rcub_vinar_6638"
}

Oka, S. N., Grubor, B., Dakić, D. V., Ilic, M., Manovic, V., Erić, M. D., Paprika, M., Oka, N., Belošević, S., Mladenovic, R.,& Crnomarković, N. Đ.. (2005). Investigation of the suitability of Serbian lignites for burning in CFBC boilers. , 13-25.
https://hdl.handle.net/21.15107/rcub_vinar_6638

Oka SN, Grubor B, Dakić DV, Ilic M, Manovic V, Erić MD, Paprika M, Oka N, Belošević S, Mladenovic R, Crnomarković NĐ. Investigation of the suitability of Serbian lignites for burning in CFBC boilers. 2005;:13-25.
https://hdl.handle.net/21.15107/rcub_vinar_6638 .

Oka, Simeon N., Grubor, Borislav, Dakić, Dragoljub V., Ilic, M., Manovic, V., Erić, Milić D., Paprika, Milijana, Oka, Nikola, Belošević, Srđan, Mladenovic, R., Crnomarković, Nenad Đ., "Investigation of the suitability of Serbian lignites for burning in CFBC boilers" (2005):13-25,
https://hdl.handle.net/21.15107/rcub_vinar_6638 .

TY  - JOUR
AU  - Manovic, V
AU  - Grubor, Borislav
PY  - 2004
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2790
AB  - The purpose of this study was to determine the cause of the experimentally noticed decrease of sulfate sulfur during a thermal treatment of coal. In the case of the pyrolysis of the investigated six coals of different rank and with a widely differing sulfur contents, the decrease of the amount of sulfate sulfur was often GT 50% and, in some cases, GT 80%. The analysis of the obtained results indicates that this effect may be attributed to the overrated values of the sulfate sulfur in coal, which are the result of certain erroneous effects of the hydrochloric acid (HCl) treatment of coal, which is used during the standard procedures for sulfate sulfur determination. It is shown that, because of the HCl treatment, a portion of the organic and/or pyritic sulfur is identified as sulfate sulfur. This effect may be expected to be more pronounced in the case of low-rank coals, as well as in coals that have a relatively large content of pyritic sulfur.
T2  - Energy and Fuels
T1  - A study of misleading effects of HCl treatment in the characterization of sulfur in coal
VL  - 18
IS  - 4
SP  - 1169
EP  - 1174
DO  - 10.1021/ef049964s
ER  - 

@article{
author = "Manovic, V and Grubor, Borislav",
year = "2004",
abstract = "The purpose of this study was to determine the cause of the experimentally noticed decrease of sulfate sulfur during a thermal treatment of coal. In the case of the pyrolysis of the investigated six coals of different rank and with a widely differing sulfur contents, the decrease of the amount of sulfate sulfur was often GT 50% and, in some cases, GT 80%. The analysis of the obtained results indicates that this effect may be attributed to the overrated values of the sulfate sulfur in coal, which are the result of certain erroneous effects of the hydrochloric acid (HCl) treatment of coal, which is used during the standard procedures for sulfate sulfur determination. It is shown that, because of the HCl treatment, a portion of the organic and/or pyritic sulfur is identified as sulfate sulfur. This effect may be expected to be more pronounced in the case of low-rank coals, as well as in coals that have a relatively large content of pyritic sulfur.",
journal = "Energy and Fuels",
title = "A study of misleading effects of HCl treatment in the characterization of sulfur in coal",
volume = "18",
number = "4",
pages = "1169-1174",
doi = "10.1021/ef049964s"
}

Manovic, V.,& Grubor, B.. (2004). A study of misleading effects of HCl treatment in the characterization of sulfur in coal. in Energy and Fuels, 18(4), 1169-1174.
https://doi.org/10.1021/ef049964s

Manovic V, Grubor B. A study of misleading effects of HCl treatment in the characterization of sulfur in coal. in Energy and Fuels. 2004;18(4):1169-1174.
doi:10.1021/ef049964s .

Manovic, V, Grubor, Borislav, "A study of misleading effects of HCl treatment in the characterization of sulfur in coal" in Energy and Fuels, 18, no. 4 (2004):1169-1174,
https://doi.org/10.1021/ef049964s . .

TY  - JOUR
AU  - Manovic, V
AU  - Grubor, Borislav
AU  - Repić, Branislav
AU  - Mladenović, Milica R.
AU  - Jovanović, Marina P.
PY  - 2003
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2689
AB  - The sulfur release during combustion of six Serbian coals of different rank (from lignite to semi-anthracite) and sulfur content (0.28 - 6.04 %) was determined by analyzing the content of various sulfur forms in coal, char and ash samples. Based on theoretical considerations and behaviour of sulfur compounds during the processes of devolatilization and char combustion, correlations are proposed for estimation of the amount of sulfur released during devolatilization as well as during the overall process of coal combustion. Both correlations take into account the results of the proximate analysis of coal and that of the sulfur forms in the coal, while for the second one the sulfur retention efficiency during char combustion (eta) is needed. The correlations were successfully verified by using the obtained experimental data, as well as the data found in literature. For most of the coals the same value of eta = 0.7 may be used, unless if the molar Ca/S ratio is significantly smaller than 1.
T2  - Fresenius Environmental Bulletin
T1  - Sulfur release during combustion of Serbian coals
VL  - 12
IS  - 11
SP  - 1348
EP  - 1353
UR  - https://hdl.handle.net/21.15107/rcub_vinar_2689
ER  - 

@article{
author = "Manovic, V and Grubor, Borislav and Repić, Branislav and Mladenović, Milica R. and Jovanović, Marina P.",
year = "2003",
abstract = "The sulfur release during combustion of six Serbian coals of different rank (from lignite to semi-anthracite) and sulfur content (0.28 - 6.04 %) was determined by analyzing the content of various sulfur forms in coal, char and ash samples. Based on theoretical considerations and behaviour of sulfur compounds during the processes of devolatilization and char combustion, correlations are proposed for estimation of the amount of sulfur released during devolatilization as well as during the overall process of coal combustion. Both correlations take into account the results of the proximate analysis of coal and that of the sulfur forms in the coal, while for the second one the sulfur retention efficiency during char combustion (eta) is needed. The correlations were successfully verified by using the obtained experimental data, as well as the data found in literature. For most of the coals the same value of eta = 0.7 may be used, unless if the molar Ca/S ratio is significantly smaller than 1.",
journal = "Fresenius Environmental Bulletin",
title = "Sulfur release during combustion of Serbian coals",
volume = "12",
number = "11",
pages = "1348-1353",
url = "https://hdl.handle.net/21.15107/rcub_vinar_2689"
}

Manovic, V., Grubor, B., Repić, B., Mladenović, M. R.,& Jovanović, M. P.. (2003). Sulfur release during combustion of Serbian coals. in Fresenius Environmental Bulletin, 12(11), 1348-1353.
https://hdl.handle.net/21.15107/rcub_vinar_2689

Manovic V, Grubor B, Repić B, Mladenović MR, Jovanović MP. Sulfur release during combustion of Serbian coals. in Fresenius Environmental Bulletin. 2003;12(11):1348-1353.
https://hdl.handle.net/21.15107/rcub_vinar_2689 .

Manovic, V, Grubor, Borislav, Repić, Branislav, Mladenović, Milica R., Jovanović, Marina P., "Sulfur release during combustion of Serbian coals" in Fresenius Environmental Bulletin, 12, no. 11 (2003):1348-1353,
https://hdl.handle.net/21.15107/rcub_vinar_2689 .

TY  - JOUR
AU  - Grubor, Borislav
AU  - Manovic, V
AU  - Oka, Simeon N.
PY  - 2003
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2688
AB  - The process of sulfur self-retention (SSR) occurs as a result of the reactions between the mineral matter in coal ash and the SO2 evolved during coal combustion. Consequently, the emission of SO2 may be significantly reduced. The results of experimental investigations and modeling of SSR is presented in this work. The transformations of sulfur forms during devolatilization are taken into account via a correlation for the amount of sulfur that remains in the char, after devolatilization. A novel approach has been applied for modeling SSR during char combustion, closely related to the grain model used for SO2 retention by limestone as a sorbent. It is assumed that SSR is a result of the reaction between SO2 and CaO in the form of uniformly distributed micro-grains in char. An unreacted shrinking core model is adopted for the reactions between the CaO micro-grains and SO2. The comparison with the experimentally obtained values in a fluidized bed reactor and in a laboratory oven, using coals of different rank (fixed carbon over volatile matter ratio, C-fix/VM = 0.75-7.40), content of sulfur forms (total 0.84-6.04%, organic 0.71-4.71%, pyritic 0-2.57%) and molar Ca/S ratio (0.34-3.17), has shown that the model can adequately predict the kinetics of the process, the levels of the obtained values of SSR efficiencies, as well as the influence of temperature, coal particle size and the surrounding conditions. (C) 2003 Elsevier B.V. All rights reserved.
T2  - Chemical Engineering Journal
T1  - An experimental and modeling study of the contribution of coal ash to SO2 capture in fluidized bed combustion
VL  - 96
IS  - 1-3
SP  - 157
EP  - 169
DO  - 10.1016/j.cej.2003.08.021
ER  - 

@article{
author = "Grubor, Borislav and Manovic, V and Oka, Simeon N.",
year = "2003",
abstract = "The process of sulfur self-retention (SSR) occurs as a result of the reactions between the mineral matter in coal ash and the SO2 evolved during coal combustion. Consequently, the emission of SO2 may be significantly reduced. The results of experimental investigations and modeling of SSR is presented in this work. The transformations of sulfur forms during devolatilization are taken into account via a correlation for the amount of sulfur that remains in the char, after devolatilization. A novel approach has been applied for modeling SSR during char combustion, closely related to the grain model used for SO2 retention by limestone as a sorbent. It is assumed that SSR is a result of the reaction between SO2 and CaO in the form of uniformly distributed micro-grains in char. An unreacted shrinking core model is adopted for the reactions between the CaO micro-grains and SO2. The comparison with the experimentally obtained values in a fluidized bed reactor and in a laboratory oven, using coals of different rank (fixed carbon over volatile matter ratio, C-fix/VM = 0.75-7.40), content of sulfur forms (total 0.84-6.04%, organic 0.71-4.71%, pyritic 0-2.57%) and molar Ca/S ratio (0.34-3.17), has shown that the model can adequately predict the kinetics of the process, the levels of the obtained values of SSR efficiencies, as well as the influence of temperature, coal particle size and the surrounding conditions. (C) 2003 Elsevier B.V. All rights reserved.",
journal = "Chemical Engineering Journal",
title = "An experimental and modeling study of the contribution of coal ash to SO2 capture in fluidized bed combustion",
volume = "96",
number = "1-3",
pages = "157-169",
doi = "10.1016/j.cej.2003.08.021"
}

Grubor, B., Manovic, V.,& Oka, S. N.. (2003). An experimental and modeling study of the contribution of coal ash to SO2 capture in fluidized bed combustion. in Chemical Engineering Journal, 96(1-3), 157-169.
https://doi.org/10.1016/j.cej.2003.08.021

Grubor B, Manovic V, Oka SN. An experimental and modeling study of the contribution of coal ash to SO2 capture in fluidized bed combustion. in Chemical Engineering Journal. 2003;96(1-3):157-169.
doi:10.1016/j.cej.2003.08.021 .

Grubor, Borislav, Manovic, V, Oka, Simeon N., "An experimental and modeling study of the contribution of coal ash to SO2 capture in fluidized bed combustion" in Chemical Engineering Journal, 96, no. 1-3 (2003):157-169,
https://doi.org/10.1016/j.cej.2003.08.021 . .

TY  - JOUR
AU  - Manovic, V
AU  - Grubor, Borislav
AU  - Ilic, M
AU  - Jovancicevic, B
PY  - 2003
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2622
AB  - An overall model for sulfur self-retention in ash during coal particle combustion is developed in this paper. It is assumed that sulfur retention during char combustion occurs due to the reaction between SO2 and CaO in the form of uniformly distributed non-porous grains. Parametric analysis shows that the process of sulfur self-retention is limited by solid difussion through the non-porous product layer formed on the CaO grains and that the most important coal characteristics which influence sulfur self-retention are coal rank. content of sulfur forms. molar Ca/S ratio and particle radius. A comparison with the experimentally obtained values in a FB reactor showed that die model can adequately predict the kinetics of the process, the levels of the obtained values of the SSR efficiencies, as well as the influence of temperature and coal particle size.
T2  - Journal of the Serbian Chemical Society
T1  - Sulfur retention by ash during coal combustion. Part II. A model of the process
VL  - 68
IS  - 3
SP  - 171
EP  - 182
DO  - 10.2298/JSC0303171M
ER  - 

@article{
author = "Manovic, V and Grubor, Borislav and Ilic, M and Jovancicevic, B",
year = "2003",
abstract = "An overall model for sulfur self-retention in ash during coal particle combustion is developed in this paper. It is assumed that sulfur retention during char combustion occurs due to the reaction between SO2 and CaO in the form of uniformly distributed non-porous grains. Parametric analysis shows that the process of sulfur self-retention is limited by solid difussion through the non-porous product layer formed on the CaO grains and that the most important coal characteristics which influence sulfur self-retention are coal rank. content of sulfur forms. molar Ca/S ratio and particle radius. A comparison with the experimentally obtained values in a FB reactor showed that die model can adequately predict the kinetics of the process, the levels of the obtained values of the SSR efficiencies, as well as the influence of temperature and coal particle size.",
journal = "Journal of the Serbian Chemical Society",
title = "Sulfur retention by ash during coal combustion. Part II. A model of the process",
volume = "68",
number = "3",
pages = "171-182",
doi = "10.2298/JSC0303171M"
}

Manovic, V., Grubor, B., Ilic, M.,& Jovancicevic, B.. (2003). Sulfur retention by ash during coal combustion. Part II. A model of the process. in Journal of the Serbian Chemical Society, 68(3), 171-182.
https://doi.org/10.2298/JSC0303171M

Manovic V, Grubor B, Ilic M, Jovancicevic B. Sulfur retention by ash during coal combustion. Part II. A model of the process. in Journal of the Serbian Chemical Society. 2003;68(3):171-182.
doi:10.2298/JSC0303171M .

Manovic, V, Grubor, Borislav, Ilic, M, Jovancicevic, B, "Sulfur retention by ash during coal combustion. Part II. A model of the process" in Journal of the Serbian Chemical Society, 68, no. 3 (2003):171-182,
https://doi.org/10.2298/JSC0303171M . .

TY  - JOUR
AU  - Ilic, M
AU  - Grubor, Borislav
AU  - Manovic, V
PY  - 2003
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2618
AB  - A model for the combustion of porous char particles as a basis for modeling the process of sulfur retention by ash dining coal combustion is developed in this paper. The model belongs to the microscopic intrinsic models and describes the dynamic behavior of a porous char particle during comustion, taking into account temporal and spatial changes of all important physical properties of the char particle and various combustion parameters. The The paramettic analysis of the enhanced model shows that the model represents a good basis for the development of a model for the process of sulfur retention by ash during coal combustion. The model enables die prediction of die values of all parameters necessary for the introduction of reactions between sulfur compounds and mineral components in ash. primarily calcium oxide.
T2  - Journal of the Serbian Chemical Society
T1  - Sulfur retention by ash during coal combustion. Part I. A model of char particle combustion
VL  - 68
IS  - 2
SP  - 137
EP  - 145
DO  - 10.2298/JSC0302137I
ER  - 

@article{
author = "Ilic, M and Grubor, Borislav and Manovic, V",
year = "2003",
abstract = "A model for the combustion of porous char particles as a basis for modeling the process of sulfur retention by ash dining coal combustion is developed in this paper. The model belongs to the microscopic intrinsic models and describes the dynamic behavior of a porous char particle during comustion, taking into account temporal and spatial changes of all important physical properties of the char particle and various combustion parameters. The The paramettic analysis of the enhanced model shows that the model represents a good basis for the development of a model for the process of sulfur retention by ash during coal combustion. The model enables die prediction of die values of all parameters necessary for the introduction of reactions between sulfur compounds and mineral components in ash. primarily calcium oxide.",
journal = "Journal of the Serbian Chemical Society",
title = "Sulfur retention by ash during coal combustion. Part I. A model of char particle combustion",
volume = "68",
number = "2",
pages = "137-145",
doi = "10.2298/JSC0302137I"
}

Ilic, M., Grubor, B.,& Manovic, V.. (2003). Sulfur retention by ash during coal combustion. Part I. A model of char particle combustion. in Journal of the Serbian Chemical Society, 68(2), 137-145.
https://doi.org/10.2298/JSC0302137I

Ilic M, Grubor B, Manovic V. Sulfur retention by ash during coal combustion. Part I. A model of char particle combustion. in Journal of the Serbian Chemical Society. 2003;68(2):137-145.
doi:10.2298/JSC0302137I .

Ilic, M, Grubor, Borislav, Manovic, V, "Sulfur retention by ash during coal combustion. Part I. A model of char particle combustion" in Journal of the Serbian Chemical Society, 68, no. 2 (2003):137-145,
https://doi.org/10.2298/JSC0302137I . .

TY  - JOUR
AU  - Grubor, Borislav
AU  - Manovic, V
PY  - 2002
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/2538
AB  - Self-retention Of SO2 by ash of different grades of Kolubara lignite was experimentally investigated in a laboratory furnace. The peculiarity of this type of coal is that in the open pit there are distinct layers of coal and ballast matter, which complicates the formation of representative samples. Two grades of this coal (differing in ballast matter content) were investigated using 3 sieved fractions: 1-1.6 mm, 2.5-3.15 mm, and 4.76-7 mm. It was found that particle size had no significant effect on the sulfur self-retention efficiency (etaSO(2)). The effect of ballast matter content on etaSO(2) was investigated by classifying two sieved fractions into classes with different density ranging from LT 1000 kg/m(3) to GT 1600 kg/m(3). It was found that most of sulfur self-retention occurs in less dense particles., For this coal only 60% of the total calcium was found to be active in relation to sulfur self-retention capability. Most of the active calcium and sulfur were found to be present in particles of lower density, which explains their dominant contribution to overall sulfur self-retention.
T2  - Energy and Fuels
T1  - Influence of non-uniformity of coal and distribution of active calcium on sulfur self-retention by ash - A case study of lignite Kolubara
VL  - 16
IS  - 4
SP  - 951
EP  - 955
DO  - 10.1021/ef0200119
ER  - 

@article{
author = "Grubor, Borislav and Manovic, V",
year = "2002",
abstract = "Self-retention Of SO2 by ash of different grades of Kolubara lignite was experimentally investigated in a laboratory furnace. The peculiarity of this type of coal is that in the open pit there are distinct layers of coal and ballast matter, which complicates the formation of representative samples. Two grades of this coal (differing in ballast matter content) were investigated using 3 sieved fractions: 1-1.6 mm, 2.5-3.15 mm, and 4.76-7 mm. It was found that particle size had no significant effect on the sulfur self-retention efficiency (etaSO(2)). The effect of ballast matter content on etaSO(2) was investigated by classifying two sieved fractions into classes with different density ranging from LT 1000 kg/m(3) to GT 1600 kg/m(3). It was found that most of sulfur self-retention occurs in less dense particles., For this coal only 60% of the total calcium was found to be active in relation to sulfur self-retention capability. Most of the active calcium and sulfur were found to be present in particles of lower density, which explains their dominant contribution to overall sulfur self-retention.",
journal = "Energy and Fuels",
title = "Influence of non-uniformity of coal and distribution of active calcium on sulfur self-retention by ash - A case study of lignite Kolubara",
volume = "16",
number = "4",
pages = "951-955",
doi = "10.1021/ef0200119"
}

Grubor, B.,& Manovic, V.. (2002). Influence of non-uniformity of coal and distribution of active calcium on sulfur self-retention by ash - A case study of lignite Kolubara. in Energy and Fuels, 16(4), 951-955.
https://doi.org/10.1021/ef0200119

Grubor B, Manovic V. Influence of non-uniformity of coal and distribution of active calcium on sulfur self-retention by ash - A case study of lignite Kolubara. in Energy and Fuels. 2002;16(4):951-955.
doi:10.1021/ef0200119 .

Grubor, Borislav, Manovic, V, "Influence of non-uniformity of coal and distribution of active calcium on sulfur self-retention by ash - A case study of lignite Kolubara" in Energy and Fuels, 16, no. 4 (2002):951-955,
https://doi.org/10.1021/ef0200119 . .