TY  - CONF
AU  - Liu, Bangjun
AU  - Bechtel, Achim
AU  - Zhao, Cunliang
AU  - Stojanović, Ksenija
AU  - Tian, Zeqi
PY  - 2023
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6398
AB  - Considering the significance of liptinite maceral group to the hydrocarbon generative potential, a comprehensive petrographical, biomarker and isotopic study is performed on liptinite-rich coal to determine the origin of organic matter (OM), depositional conditions and maturity. The samples were collected from the Pliocene Jinsuo Basin (samples YNP and YND) and Eocene Shenbei Basin (sample SB) in China. The obtained results indicate mixed gymnosperm (Pinacea) and angiosperm sources of OM in the sporinite dominated YNP sample. The immature OM (Rr=0.25%) was deposited under oxidizing conditions with pronounced microbial activity. The OM of the resinite-rich YND sample was mostly derived from woody parts of plants and deposited under reducing conditions. The presence of polycyclic aromatic hydrocarbons at low maturity level (Rr=0.23%) is indicative for certain post-depositional events and/or palaeo-wildfires, that may be responsible for the observation of two kinds of resinite in this sample. The main sources of OM in the resinite-rich sample SB (Rr = 0.46%) were species of the conifer families Cupressaceae and Pinaceae. The OM was deposited under reducing conditions, with a very limited microbial activity. The δ2D values of all extracted liptinite-rich coal are lower than that of coal/kerogen, and falls in the range of lipids and resins.
PB  - European Association of Geoscientists and Engineers
C3  - 31st International Meeting on Organic Geochemistry
T1  - Comprehensive Study of Liptinite-Rich Coal from the Pliocene Jinsuo Basin and the Eocene Shenbei Basin (China)
SP  - 1
EP  - 2
DO  - 10.3997/2214-4609.202333066
ER  - 

@conference{
author = "Liu, Bangjun and Bechtel, Achim and Zhao, Cunliang and Stojanović, Ksenija and Tian, Zeqi",
year = "2023",
abstract = "Considering the significance of liptinite maceral group to the hydrocarbon generative potential, a comprehensive petrographical, biomarker and isotopic study is performed on liptinite-rich coal to determine the origin of organic matter (OM), depositional conditions and maturity. The samples were collected from the Pliocene Jinsuo Basin (samples YNP and YND) and Eocene Shenbei Basin (sample SB) in China. The obtained results indicate mixed gymnosperm (Pinacea) and angiosperm sources of OM in the sporinite dominated YNP sample. The immature OM (Rr=0.25%) was deposited under oxidizing conditions with pronounced microbial activity. The OM of the resinite-rich YND sample was mostly derived from woody parts of plants and deposited under reducing conditions. The presence of polycyclic aromatic hydrocarbons at low maturity level (Rr=0.23%) is indicative for certain post-depositional events and/or palaeo-wildfires, that may be responsible for the observation of two kinds of resinite in this sample. The main sources of OM in the resinite-rich sample SB (Rr = 0.46%) were species of the conifer families Cupressaceae and Pinaceae. The OM was deposited under reducing conditions, with a very limited microbial activity. The δ2D values of all extracted liptinite-rich coal are lower than that of coal/kerogen, and falls in the range of lipids and resins.",
publisher = "European Association of Geoscientists and Engineers",
journal = "31st International Meeting on Organic Geochemistry",
title = "Comprehensive Study of Liptinite-Rich Coal from the Pliocene Jinsuo Basin and the Eocene Shenbei Basin (China)",
pages = "1-2",
doi = "10.3997/2214-4609.202333066"
}

Liu, B., Bechtel, A., Zhao, C., Stojanović, K.,& Tian, Z.. (2023). Comprehensive Study of Liptinite-Rich Coal from the Pliocene Jinsuo Basin and the Eocene Shenbei Basin (China). in 31st International Meeting on Organic Geochemistry
European Association of Geoscientists and Engineers., 1-2.
https://doi.org/10.3997/2214-4609.202333066

Liu B, Bechtel A, Zhao C, Stojanović K, Tian Z. Comprehensive Study of Liptinite-Rich Coal from the Pliocene Jinsuo Basin and the Eocene Shenbei Basin (China). in 31st International Meeting on Organic Geochemistry. 2023;:1-2.
doi:10.3997/2214-4609.202333066 .

Liu, Bangjun, Bechtel, Achim, Zhao, Cunliang, Stojanović, Ksenija, Tian, Zeqi, "Comprehensive Study of Liptinite-Rich Coal from the Pliocene Jinsuo Basin and the Eocene Shenbei Basin (China)" in 31st International Meeting on Organic Geochemistry (2023):1-2,
https://doi.org/10.3997/2214-4609.202333066 . .

TY  - CONF
AU  - Zdravkov, Alexander
AU  - Gross, Doris
AU  - Bechtel, Achim
AU  - Stojanović, Ksenija
AU  - Kojić, Ivan
PY  - 2023
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6402
AB  - Three 0.2-0.6 m thick coal seams, representing seam splits from a locally thicker seam (~1.8
m), comprise the Eocene Suhostrel coal deposit from the S-SW margin of the E1-2-Ol1 Padesh
Graben. High TOC contents (avg. ~86 wt.%, daf), VR (avg. Ro = 1.05%) and Tmax (avg. 457°C),
argue for high vol. A/medium vol. bituminous coalification rank. Maceral composition is
dominated by vitrinite (avg. ~ 95 vol.%), represented by detrovitrinite (e.g., collodetrinite, avg.
37.5 vol.%, and vitrodetrinite, avg. 19.2 vol.%) and collotelinite (avg. 38.0 vol.%, mostly
gelified leaf-derived tissues, e.g. phyllo-vitrinite). Liptinite (avg. ~5 vol.%) includes cutinite
and microsporinite. Predominance of mid- and long-chain n-alkanes argues for peat formation
from a mixture of aquatic macrophytes and terrestrial vascular plants. Low Vegetation Index
values (VI = 0.1-3.2, avg. 0.8; Calder et al., 1991) denote major organic matter contribution
from vegetation with poor preservation potential. This is compatible with the presence of
oleanane, confirming input from angiosperm plants. The absence of resin-derived sesqui- and
diterpenoid hydrocarbons argues for an insignificant role of conifers during peat formation.
Reconstructed depositional settings (Fig. 1) argue for organic matter deposition under marginal
aquatic, marsh/fen-type peatland with meso- to rheotrophic characteristics (Groundwater Index,
GWI = 0.3-7.2, avg. 1.4; Calder et al., 1991). High mineral matter contents (ash yields 21-47
wt.%) imply hydrologically active environment with frequent (perhaps seasonal) changes in Eh
settings. Low concentrations of hopanoid biomarkers imply limited aerobic degradation of the
plant remains. Post-depositional marine influence and downward infiltrating sulfate-rich waters
are considered responsible for the presence of dibenzothiophene and its methylated derivatives.
PB  - Geological Society of Greece
C3  - Joint 74th ICCP and 39th TSOP Meeting 17th – 24th September 2023, Patras, Greece
C3  - Bulletin of the Geological Society Special Publication
T1  - Paleoenvironmental settings of peat formation within Padesh Graben, SW Bulgaria, deduced from maceral analysis and geochemical properties of Suhostrel Coal
VL  - 12
SP  - 53
EP  - 53
UR  - https://hdl.handle.net/21.15107/rcub_cherry_6402
ER  - 

@conference{
author = "Zdravkov, Alexander and Gross, Doris and Bechtel, Achim and Stojanović, Ksenija and Kojić, Ivan",
year = "2023",
abstract = "Three 0.2-0.6 m thick coal seams, representing seam splits from a locally thicker seam (~1.8
m), comprise the Eocene Suhostrel coal deposit from the S-SW margin of the E1-2-Ol1 Padesh
Graben. High TOC contents (avg. ~86 wt.%, daf), VR (avg. Ro = 1.05%) and Tmax (avg. 457°C),
argue for high vol. A/medium vol. bituminous coalification rank. Maceral composition is
dominated by vitrinite (avg. ~ 95 vol.%), represented by detrovitrinite (e.g., collodetrinite, avg.
37.5 vol.%, and vitrodetrinite, avg. 19.2 vol.%) and collotelinite (avg. 38.0 vol.%, mostly
gelified leaf-derived tissues, e.g. phyllo-vitrinite). Liptinite (avg. ~5 vol.%) includes cutinite
and microsporinite. Predominance of mid- and long-chain n-alkanes argues for peat formation
from a mixture of aquatic macrophytes and terrestrial vascular plants. Low Vegetation Index
values (VI = 0.1-3.2, avg. 0.8; Calder et al., 1991) denote major organic matter contribution
from vegetation with poor preservation potential. This is compatible with the presence of
oleanane, confirming input from angiosperm plants. The absence of resin-derived sesqui- and
diterpenoid hydrocarbons argues for an insignificant role of conifers during peat formation.
Reconstructed depositional settings (Fig. 1) argue for organic matter deposition under marginal
aquatic, marsh/fen-type peatland with meso- to rheotrophic characteristics (Groundwater Index,
GWI = 0.3-7.2, avg. 1.4; Calder et al., 1991). High mineral matter contents (ash yields 21-47
wt.%) imply hydrologically active environment with frequent (perhaps seasonal) changes in Eh
settings. Low concentrations of hopanoid biomarkers imply limited aerobic degradation of the
plant remains. Post-depositional marine influence and downward infiltrating sulfate-rich waters
are considered responsible for the presence of dibenzothiophene and its methylated derivatives.",
publisher = "Geological Society of Greece",
journal = "Joint 74th ICCP and 39th TSOP Meeting 17th – 24th September 2023, Patras, Greece, Bulletin of the Geological Society Special Publication",
title = "Paleoenvironmental settings of peat formation within Padesh Graben, SW Bulgaria, deduced from maceral analysis and geochemical properties of Suhostrel Coal",
volume = "12",
pages = "53-53",
url = "https://hdl.handle.net/21.15107/rcub_cherry_6402"
}

Zdravkov, A., Gross, D., Bechtel, A., Stojanović, K.,& Kojić, I.. (2023). Paleoenvironmental settings of peat formation within Padesh Graben, SW Bulgaria, deduced from maceral analysis and geochemical properties of Suhostrel Coal. in Joint 74th ICCP and 39th TSOP Meeting 17th – 24th September 2023, Patras, Greece
Geological Society of Greece., 12, 53-53.
https://hdl.handle.net/21.15107/rcub_cherry_6402

Zdravkov A, Gross D, Bechtel A, Stojanović K, Kojić I. Paleoenvironmental settings of peat formation within Padesh Graben, SW Bulgaria, deduced from maceral analysis and geochemical properties of Suhostrel Coal. in Joint 74th ICCP and 39th TSOP Meeting 17th – 24th September 2023, Patras, Greece. 2023;12:53-53.
https://hdl.handle.net/21.15107/rcub_cherry_6402 .

Zdravkov, Alexander, Gross, Doris, Bechtel, Achim, Stojanović, Ksenija, Kojić, Ivan, "Paleoenvironmental settings of peat formation within Padesh Graben, SW Bulgaria, deduced from maceral analysis and geochemical properties of Suhostrel Coal" in Joint 74th ICCP and 39th TSOP Meeting 17th – 24th September 2023, Patras, Greece, 12 (2023):53-53,
https://hdl.handle.net/21.15107/rcub_cherry_6402 .

TY  - CONF
AU  - Kus, Jolanta
AU  - Dolezych, Martina
AU  - Schneider, Wilfrid
AU  - Hower, James
AU  - Hofmann, Tamás
AU  - Visiné Rajczi, Eszter
AU  - Sachsenhofer, Reinhard
AU  - Bechtel, Achim
AU  - Stojanović, Ksenija
AU  - Životić, Dragana
AU  - Kojić, Ivan
AU  - Mastalerz, Maria
AU  - Graupner, Torsten
AU  - Lukens, William
AU  - Donaldson, Lloyd
PY  - 2023
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6401
AB  - Fossil wood with well-preserved cellulose is detected in open-cast mines of the Miocene Lusatia lignite-mining district (eastern Germany). Aimed to explain the preservation of cellulose, an organic geochemical study was performed on the fossil wood samples and intact heartwood tissues of the respective modern woody species. The results of micro Fourier transform infrared (micro-FTIR) spectroscopy, biomarker distributions and δ13C values indicate that the preservation of cellulose in fossil wood samples was governed by reducing conditions. Furthermore, it can be also attributed to weathering of the surrounding tuff- and rhyolite-dominated acidic volcanic rock that might have caused lowering of pH. All fossil wood samples contain minor hopanoids, implying negligible post-depositional microbial degradation of OM. Limited microbial degradation of OM could be also caused by protection of the wood by conifer resins. For example, fossil Cupressaceae sensu lato, as confirmed by detection of hibaene, totarane, and cuparene, was more resinous than the modern forms. The absence of perylene in fossil wood indicates the limited degradation of wood by fungi.
PB  - European Association of Geoscientists and Engineers
C3  - 31st International Meeting on Organic Geochemistry
T1  - The Preservation of Cellulose in Fossil Wood – Implications from Organic Geochemical Study of Fossil and Modern Wood
SP  - 109
EP  - 109
DO  - 10.3997/2214-4609.202333109
ER  - 

@conference{
author = "Kus, Jolanta and Dolezych, Martina and Schneider, Wilfrid and Hower, James and Hofmann, Tamás and Visiné Rajczi, Eszter and Sachsenhofer, Reinhard and Bechtel, Achim and Stojanović, Ksenija and Životić, Dragana and Kojić, Ivan and Mastalerz, Maria and Graupner, Torsten and Lukens, William and Donaldson, Lloyd",
year = "2023",
abstract = "Fossil wood with well-preserved cellulose is detected in open-cast mines of the Miocene Lusatia lignite-mining district (eastern Germany). Aimed to explain the preservation of cellulose, an organic geochemical study was performed on the fossil wood samples and intact heartwood tissues of the respective modern woody species. The results of micro Fourier transform infrared (micro-FTIR) spectroscopy, biomarker distributions and δ13C values indicate that the preservation of cellulose in fossil wood samples was governed by reducing conditions. Furthermore, it can be also attributed to weathering of the surrounding tuff- and rhyolite-dominated acidic volcanic rock that might have caused lowering of pH. All fossil wood samples contain minor hopanoids, implying negligible post-depositional microbial degradation of OM. Limited microbial degradation of OM could be also caused by protection of the wood by conifer resins. For example, fossil Cupressaceae sensu lato, as confirmed by detection of hibaene, totarane, and cuparene, was more resinous than the modern forms. The absence of perylene in fossil wood indicates the limited degradation of wood by fungi.",
publisher = "European Association of Geoscientists and Engineers",
journal = "31st International Meeting on Organic Geochemistry",
title = "The Preservation of Cellulose in Fossil Wood – Implications from Organic Geochemical Study of Fossil and Modern Wood",
pages = "109-109",
doi = "10.3997/2214-4609.202333109"
}

Kus, J., Dolezych, M., Schneider, W., Hower, J., Hofmann, T., Visiné Rajczi, E., Sachsenhofer, R., Bechtel, A., Stojanović, K., Životić, D., Kojić, I., Mastalerz, M., Graupner, T., Lukens, W.,& Donaldson, L.. (2023). The Preservation of Cellulose in Fossil Wood – Implications from Organic Geochemical Study of Fossil and Modern Wood. in 31st International Meeting on Organic Geochemistry
European Association of Geoscientists and Engineers., 109-109.
https://doi.org/10.3997/2214-4609.202333109

Kus J, Dolezych M, Schneider W, Hower J, Hofmann T, Visiné Rajczi E, Sachsenhofer R, Bechtel A, Stojanović K, Životić D, Kojić I, Mastalerz M, Graupner T, Lukens W, Donaldson L. The Preservation of Cellulose in Fossil Wood – Implications from Organic Geochemical Study of Fossil and Modern Wood. in 31st International Meeting on Organic Geochemistry. 2023;:109-109.
doi:10.3997/2214-4609.202333109 .

Kus, Jolanta, Dolezych, Martina, Schneider, Wilfrid, Hower, James, Hofmann, Tamás, Visiné Rajczi, Eszter, Sachsenhofer, Reinhard, Bechtel, Achim, Stojanović, Ksenija, Životić, Dragana, Kojić, Ivan, Mastalerz, Maria, Graupner, Torsten, Lukens, William, Donaldson, Lloyd, "The Preservation of Cellulose in Fossil Wood – Implications from Organic Geochemical Study of Fossil and Modern Wood" in 31st International Meeting on Organic Geochemistry (2023):109-109,
https://doi.org/10.3997/2214-4609.202333109 . .

TY  - CONF
AU  - Zdravkov, Alexander
AU  - Gross, Doris
AU  - Stojanović, Ksenija
AU  - Bechtel, Achim
AU  - Kojić, Ivan
PY  - 2023
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6399
AB  - In the current study formation of coal in the Suhostrel (Early-Mid Eocene) and the Bobov Dol (Late Oligocene) basins located in the SW Bulgaria was evaluated using organic petrographic characteristics and biomarker patterns. Furthermore, the potential of biomarkers to indicate climate cooling trend in the late Oligocene, which was less pronounced in Bulgaria compared to the global one was examined. Studied coals significantly differ in their coalification degree: Suhostrel (Ro ~ 1.10%), Bobov Dol (Ro ~ 0.45–0.50%). The obtained results show that main organic matter (OM) sources of Bobov Dol coal were mixed Pinaceae/Cupressaceae conifer communities from moderately wet oligo- to mesotrophic swamps. OM of Suhostrel coal is mainly derived from mixed angiosperm hydrophytic and woody vegetation, with the predominance of the former. The peatification was performed under reducing conditions with occasional marine ingressions into the paleomire. Although comparison of biomarker patterns at different OM maturity levels is complicated, some relevant indication can be observed from the compositions of non-hopanoid terpenoids, which showed that mild late Oligocene climate cooling in Bulgaria was associated with change from hydrophytic angiosperm- to gymnosperm-dominated peatlands. This is consistent with the results of investigation of the Bulgarian Paleogene flora.
PB  - European Association of Geoscientists and Engineers
C3  - 31st International Meeting on Organic Geochemistry
T1  - Comparative Petrographical and Organic Geochemical Study of Eocene and Oligocene Coal Basins from Sw Bulgaria
SP  - 1
EP  - 2
DO  - 10.3997/2214-4609.202333034
ER  - 

@conference{
author = "Zdravkov, Alexander and Gross, Doris and Stojanović, Ksenija and Bechtel, Achim and Kojić, Ivan",
year = "2023",
abstract = "In the current study formation of coal in the Suhostrel (Early-Mid Eocene) and the Bobov Dol (Late Oligocene) basins located in the SW Bulgaria was evaluated using organic petrographic characteristics and biomarker patterns. Furthermore, the potential of biomarkers to indicate climate cooling trend in the late Oligocene, which was less pronounced in Bulgaria compared to the global one was examined. Studied coals significantly differ in their coalification degree: Suhostrel (Ro ~ 1.10%), Bobov Dol (Ro ~ 0.45–0.50%). The obtained results show that main organic matter (OM) sources of Bobov Dol coal were mixed Pinaceae/Cupressaceae conifer communities from moderately wet oligo- to mesotrophic swamps. OM of Suhostrel coal is mainly derived from mixed angiosperm hydrophytic and woody vegetation, with the predominance of the former. The peatification was performed under reducing conditions with occasional marine ingressions into the paleomire. Although comparison of biomarker patterns at different OM maturity levels is complicated, some relevant indication can be observed from the compositions of non-hopanoid terpenoids, which showed that mild late Oligocene climate cooling in Bulgaria was associated with change from hydrophytic angiosperm- to gymnosperm-dominated peatlands. This is consistent with the results of investigation of the Bulgarian Paleogene flora.",
publisher = "European Association of Geoscientists and Engineers",
journal = "31st International Meeting on Organic Geochemistry",
title = "Comparative Petrographical and Organic Geochemical Study of Eocene and Oligocene Coal Basins from Sw Bulgaria",
pages = "1-2",
doi = "10.3997/2214-4609.202333034"
}

Zdravkov, A., Gross, D., Stojanović, K., Bechtel, A.,& Kojić, I.. (2023). Comparative Petrographical and Organic Geochemical Study of Eocene and Oligocene Coal Basins from Sw Bulgaria. in 31st International Meeting on Organic Geochemistry
European Association of Geoscientists and Engineers., 1-2.
https://doi.org/10.3997/2214-4609.202333034

Zdravkov A, Gross D, Stojanović K, Bechtel A, Kojić I. Comparative Petrographical and Organic Geochemical Study of Eocene and Oligocene Coal Basins from Sw Bulgaria. in 31st International Meeting on Organic Geochemistry. 2023;:1-2.
doi:10.3997/2214-4609.202333034 .

Zdravkov, Alexander, Gross, Doris, Stojanović, Ksenija, Bechtel, Achim, Kojić, Ivan, "Comparative Petrographical and Organic Geochemical Study of Eocene and Oligocene Coal Basins from Sw Bulgaria" in 31st International Meeting on Organic Geochemistry (2023):1-2,
https://doi.org/10.3997/2214-4609.202333034 . .

TY  - CONF
AU  - Zdravkov, Alexander
AU  - Bechtel, Achim
AU  - Gross, Doris
AU  - Stojanović, Ksenija
PY  - 2023
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6403
AB  - Up to fourteen sub-bituminous coal beds are hosted within the Oligocene Bobov Dol Basin.
Among them, six (numbered I to VI from base to top) are considered economically significant.
In this study, ninety samples from five of the main seams (I-V) and a locally mined sub-seam
(Ia) were characterized by maceral analysis and ash yield determination. The coal is composed
of huminite (avg. 86.6 vol.%), liptinite (avg. 17.5 vol.%) and minor inertinite (avg: 1.5 vol.%).
Maceral composition is dominated by gymnosperm-derived telohuminite (up to 72.0 vol.%)
with resinite (up to 28.0 vol.%) and exsudatinite (up to 16.0 vol.%) cell infillings, embedded in
attrinitic (avg. 21.0 vol.%) or densinitic (avg. 17.0 vol.%) groundmass. Most samples also
contain abundant leaf-derived huminte (phyllo-huminite, up to 29.0 vol.%) in association with
cutinite (up to 8.0 vol.%) and fluorinite (up to 5.0 vol.%). Low to moderate ash yields (< 25
wt.% for most samples) coupled with low to moderate values of the maceral indices, namely
TPI < 3 (for ~80% of the samples) and GI < 3 (for >53% of the samples), and low values of the
GWI < 1 (for 81% of the samples), denote organic matter deposition within an oligo- to
mesotrophic topogenous mire with (ground)watertable beneath the peat surface. Reconstruction
of paleoenvironmental settings based on maceral analysis (Fig. 1) argues for plant matter
accumulation under marginal aquatic (seam Ia) and moderately wet- to dry-forested mires
(seams I-V). Abundance of resinite and fluorinite-rich (phyllo-)huminite indicates development
of conifer-dominated forests (likely deciduous gymnosperms), perhaps within a background of
herbaceous plants and/or deciduous shrubs. The data is compatible with the previously reported
preliminary organic geochemical data for part of the seams (Zdravkov et al., 2021).
PB  - Geological Society of Greece
C3  - Joint 74th ICCP and 39th TSOP Meeting 17th – 24th September 2023, Patras, Greece
C3  - Bulletin of the Geological Society Special Publication
T1  - Reconstruction of peat-forming paleoenvironments within the Oligocene Bobov Dol Basin, SW Bulgaria: Insights from organic petrology
VL  - 12
SP  - 52
EP  - 52
UR  - https://hdl.handle.net/21.15107/rcub_cherry_6403
ER  - 

@conference{
author = "Zdravkov, Alexander and Bechtel, Achim and Gross, Doris and Stojanović, Ksenija",
year = "2023",
abstract = "Up to fourteen sub-bituminous coal beds are hosted within the Oligocene Bobov Dol Basin.
Among them, six (numbered I to VI from base to top) are considered economically significant.
In this study, ninety samples from five of the main seams (I-V) and a locally mined sub-seam
(Ia) were characterized by maceral analysis and ash yield determination. The coal is composed
of huminite (avg. 86.6 vol.%), liptinite (avg. 17.5 vol.%) and minor inertinite (avg: 1.5 vol.%).
Maceral composition is dominated by gymnosperm-derived telohuminite (up to 72.0 vol.%)
with resinite (up to 28.0 vol.%) and exsudatinite (up to 16.0 vol.%) cell infillings, embedded in
attrinitic (avg. 21.0 vol.%) or densinitic (avg. 17.0 vol.%) groundmass. Most samples also
contain abundant leaf-derived huminte (phyllo-huminite, up to 29.0 vol.%) in association with
cutinite (up to 8.0 vol.%) and fluorinite (up to 5.0 vol.%). Low to moderate ash yields (< 25
wt.% for most samples) coupled with low to moderate values of the maceral indices, namely
TPI < 3 (for ~80% of the samples) and GI < 3 (for >53% of the samples), and low values of the
GWI < 1 (for 81% of the samples), denote organic matter deposition within an oligo- to
mesotrophic topogenous mire with (ground)watertable beneath the peat surface. Reconstruction
of paleoenvironmental settings based on maceral analysis (Fig. 1) argues for plant matter
accumulation under marginal aquatic (seam Ia) and moderately wet- to dry-forested mires
(seams I-V). Abundance of resinite and fluorinite-rich (phyllo-)huminite indicates development
of conifer-dominated forests (likely deciduous gymnosperms), perhaps within a background of
herbaceous plants and/or deciduous shrubs. The data is compatible with the previously reported
preliminary organic geochemical data for part of the seams (Zdravkov et al., 2021).",
publisher = "Geological Society of Greece",
journal = "Joint 74th ICCP and 39th TSOP Meeting 17th – 24th September 2023, Patras, Greece, Bulletin of the Geological Society Special Publication",
title = "Reconstruction of peat-forming paleoenvironments within the Oligocene Bobov Dol Basin, SW Bulgaria: Insights from organic petrology",
volume = "12",
pages = "52-52",
url = "https://hdl.handle.net/21.15107/rcub_cherry_6403"
}

Zdravkov, A., Bechtel, A., Gross, D.,& Stojanović, K.. (2023). Reconstruction of peat-forming paleoenvironments within the Oligocene Bobov Dol Basin, SW Bulgaria: Insights from organic petrology. in Joint 74th ICCP and 39th TSOP Meeting 17th – 24th September 2023, Patras, Greece
Geological Society of Greece., 12, 52-52.
https://hdl.handle.net/21.15107/rcub_cherry_6403

Zdravkov A, Bechtel A, Gross D, Stojanović K. Reconstruction of peat-forming paleoenvironments within the Oligocene Bobov Dol Basin, SW Bulgaria: Insights from organic petrology. in Joint 74th ICCP and 39th TSOP Meeting 17th – 24th September 2023, Patras, Greece. 2023;12:52-52.
https://hdl.handle.net/21.15107/rcub_cherry_6403 .

Zdravkov, Alexander, Bechtel, Achim, Gross, Doris, Stojanović, Ksenija, "Reconstruction of peat-forming paleoenvironments within the Oligocene Bobov Dol Basin, SW Bulgaria: Insights from organic petrology" in Joint 74th ICCP and 39th TSOP Meeting 17th – 24th September 2023, Patras, Greece, 12 (2023):52-52,
https://hdl.handle.net/21.15107/rcub_cherry_6403 .

TY  - JOUR
AU  - Zdravkov, Alexander
AU  - Groß, Doris
AU  - Bechtel, Achim
AU  - Stojanović, Ksenija
AU  - Kojić, Ivan
PY  - 2023
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/6288
AB  - The paper reports results from organic petrological and geochemical characterization of Suhostrel bituminous coal deposit, SW Bulgaria. Three high ash (21–47 wt%) and thin (up to 0.6 m) coal seams, representing splits from a locally compact coal bed (∼1.8 m thick), were formed around the southern and south-western rim of the Padesh Graben during its Eocene evolution. High total organic carbon contents (avg. ∼86 wt%, daf), vitrinite reflectance (avg. Ro = 1.05%) and Tmax (avg. 457 °C) argue for high vol. A/medium vol. bituminous coalification rank. Maceral composition is dominated by vitrinite (avg. ∼ 95 vol%), accompanied by small amounts of liptinite (avg. ∼ 5 vol%). Apart from few occurrences of funginite, inertinite is not present. The organic matter is mostly represented by detrovitrinite and collotelinite, the latter generally occurring in the form of gelified leaf-derived tissues. Liptinite is mainly represented by cutinite and microsporinite and display no evidence for organic matter contribution from algae. Low TPI and VI indices indicate peat formation from vegetation with poor preservation potential. Insignificant contents of gelovitrinite, coupled with high GI indices denote greater importance of the geochemical processes for the gelification of the organic matter. Striking predominance of mid- and long-chain n-alkanes argues for peat formation from a mixture of aquatic macrophytes and terrestrial vegetational communities. Presence of oleanane, albeit in low concentration, provides robust argument for contribution from angiosperm plants, whereas absence of resin-derived sesqui- and diterpenoid hydrocarbons denotes insignificant role of conifers during peat accumulation. Reconstructed depositional settings indicate organic matter accumulation under marginal aquatic, marsh/fen-type peatland with meso- to rheotrophic characteristics (GWI > 0.5). High mineral matter contents, coupled with the abundance of siliciclastic grains, imply hydrologically active environment. Plant remains deposited under oxidizing conditions (Pr/Ph = 1.5–2.5), but because of high water table were likely subjected to frequent (perhaps seasonal) changes in Eh settings. The resultant limited aerobic biodegradation of the plant remains is evidenced by low concentrations of hopanoid biomarkers and their diagenetic degradation products – drimane-type sesquiterpenoids. Post-depositional marine influence and downward infiltrating sulfate-rich waters is considered responsible for the presence of dibenzothiophene derivatives in Suhostrel coal. All molecular maturity-related ratios (e.g. CPI, Ts/(Ts + Tm), βα/(αβ + βα) C30 hopanes, ββ/(ββ + αα) C29 steranes, MPI-1, etc.) are fully compatible with the bulk geochemical parameters (e.g., TOC, Tmax, Ro) and confirm the bituminous coalification rank of the coal. Based on this data, temperatures of ∼130–140 °C were likely reached during burial of the sediments in a zone, characterized by high thermal influx (geothermal gradient ∼43–47 °C/km).
PB  - Elsevier
T2  - International Journal of Coal Geology
T1  - Depositional settings of the Eocene Suhostrel bituminous coal, SW Bulgaria, inferred from organic petrology and molecular proxies
VL  - 276
SP  - 104319
DO  - 10.1016/j.coal.2023.104319
ER  - 

@article{
author = "Zdravkov, Alexander and Groß, Doris and Bechtel, Achim and Stojanović, Ksenija and Kojić, Ivan",
year = "2023",
abstract = "The paper reports results from organic petrological and geochemical characterization of Suhostrel bituminous coal deposit, SW Bulgaria. Three high ash (21–47 wt%) and thin (up to 0.6 m) coal seams, representing splits from a locally compact coal bed (∼1.8 m thick), were formed around the southern and south-western rim of the Padesh Graben during its Eocene evolution. High total organic carbon contents (avg. ∼86 wt%, daf), vitrinite reflectance (avg. Ro = 1.05%) and Tmax (avg. 457 °C) argue for high vol. A/medium vol. bituminous coalification rank. Maceral composition is dominated by vitrinite (avg. ∼ 95 vol%), accompanied by small amounts of liptinite (avg. ∼ 5 vol%). Apart from few occurrences of funginite, inertinite is not present. The organic matter is mostly represented by detrovitrinite and collotelinite, the latter generally occurring in the form of gelified leaf-derived tissues. Liptinite is mainly represented by cutinite and microsporinite and display no evidence for organic matter contribution from algae. Low TPI and VI indices indicate peat formation from vegetation with poor preservation potential. Insignificant contents of gelovitrinite, coupled with high GI indices denote greater importance of the geochemical processes for the gelification of the organic matter. Striking predominance of mid- and long-chain n-alkanes argues for peat formation from a mixture of aquatic macrophytes and terrestrial vegetational communities. Presence of oleanane, albeit in low concentration, provides robust argument for contribution from angiosperm plants, whereas absence of resin-derived sesqui- and diterpenoid hydrocarbons denotes insignificant role of conifers during peat accumulation. Reconstructed depositional settings indicate organic matter accumulation under marginal aquatic, marsh/fen-type peatland with meso- to rheotrophic characteristics (GWI > 0.5). High mineral matter contents, coupled with the abundance of siliciclastic grains, imply hydrologically active environment. Plant remains deposited under oxidizing conditions (Pr/Ph = 1.5–2.5), but because of high water table were likely subjected to frequent (perhaps seasonal) changes in Eh settings. The resultant limited aerobic biodegradation of the plant remains is evidenced by low concentrations of hopanoid biomarkers and their diagenetic degradation products – drimane-type sesquiterpenoids. Post-depositional marine influence and downward infiltrating sulfate-rich waters is considered responsible for the presence of dibenzothiophene derivatives in Suhostrel coal. All molecular maturity-related ratios (e.g. CPI, Ts/(Ts + Tm), βα/(αβ + βα) C30 hopanes, ββ/(ββ + αα) C29 steranes, MPI-1, etc.) are fully compatible with the bulk geochemical parameters (e.g., TOC, Tmax, Ro) and confirm the bituminous coalification rank of the coal. Based on this data, temperatures of ∼130–140 °C were likely reached during burial of the sediments in a zone, characterized by high thermal influx (geothermal gradient ∼43–47 °C/km).",
publisher = "Elsevier",
journal = "International Journal of Coal Geology",
title = "Depositional settings of the Eocene Suhostrel bituminous coal, SW Bulgaria, inferred from organic petrology and molecular proxies",
volume = "276",
pages = "104319",
doi = "10.1016/j.coal.2023.104319"
}

Zdravkov, A., Groß, D., Bechtel, A., Stojanović, K.,& Kojić, I.. (2023). Depositional settings of the Eocene Suhostrel bituminous coal, SW Bulgaria, inferred from organic petrology and molecular proxies. in International Journal of Coal Geology
Elsevier., 276, 104319.
https://doi.org/10.1016/j.coal.2023.104319

Zdravkov A, Groß D, Bechtel A, Stojanović K, Kojić I. Depositional settings of the Eocene Suhostrel bituminous coal, SW Bulgaria, inferred from organic petrology and molecular proxies. in International Journal of Coal Geology. 2023;276:104319.
doi:10.1016/j.coal.2023.104319 .

Zdravkov, Alexander, Groß, Doris, Bechtel, Achim, Stojanović, Ksenija, Kojić, Ivan, "Depositional settings of the Eocene Suhostrel bituminous coal, SW Bulgaria, inferred from organic petrology and molecular proxies" in International Journal of Coal Geology, 276 (2023):104319,
https://doi.org/10.1016/j.coal.2023.104319 . .

TY  - JOUR
AU  - Kojić, Ivan
AU  - Bechtel, Achim
AU  - Aleksić, Nikoleta
AU  - Životić, Dragana R.
AU  - Trifunović, Snežana S.
AU  - Gajica, Gordana
AU  - Stojanović, Ksenija A.
PY  - 2021
UR  - https://www.mdpi.com/2073-4360/13/5/759
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/4397
AB  - The mutual impact of low-quality lignite and high-density polyethylene (HDPE) during open system pyrolysis was investigated, aiming to improve utilization of lignite with simultaneous treatment of HDPE waste. Pyrolysis of lignite, HDPE, and their mixture (mass ratio, 1:1) was performed at temperatures 400, 450, 500, 550, and 600 °C. Initial substrates and pyrolysis products were characterized by thermogravimetric analysis (TGA), gas chromatography–mass spectrometry (GC–MS), specific carbon isotope analysis of individual hydrocarbons (δ13C), Rock-Eval pyrolysis, and elemental analysis. The positive synergetic effect during co-pyrolysis of lignite/HDPE mixture was observed at temperatures ≥450 °C, with the greatest being at 500 °C. The highest yield of liquid co-pyrolysis products with a similar composition to that of crude oils is also noticed at 500 °C. The yields of liquid and gaseous products and quality of pyrolytic products obtained by co-pyrolysis of lignite/HDPE mixture are notably improved compared with pyrolysis of lignite alone. On the other hand, data obtained from pyrolysis of HDPE alone indicate that it cannot be concurrent to well-developed catalytic thermal processes for polymer recycling. However, concerning the huge amount of produced HDPE, at least part of this plastic material can be reused for advanced thermal treatment of lignite, particularly in countries where this low-rank coal represents the main source of energy.
PB  - MDPI
T2  - Polymers
T1  - Study of the synergetic effect of co-pyrolysis of lignite and high-density polyethylene aiming to improve utilization of low-rank coal
VL  - 13
IS  - 5
SP  - 759
DO  - 10.3390/polym13050759
ER  - 

@article{
author = "Kojić, Ivan and Bechtel, Achim and Aleksić, Nikoleta and Životić, Dragana R. and Trifunović, Snežana S. and Gajica, Gordana and Stojanović, Ksenija A.",
year = "2021",
abstract = "The mutual impact of low-quality lignite and high-density polyethylene (HDPE) during open system pyrolysis was investigated, aiming to improve utilization of lignite with simultaneous treatment of HDPE waste. Pyrolysis of lignite, HDPE, and their mixture (mass ratio, 1:1) was performed at temperatures 400, 450, 500, 550, and 600 °C. Initial substrates and pyrolysis products were characterized by thermogravimetric analysis (TGA), gas chromatography–mass spectrometry (GC–MS), specific carbon isotope analysis of individual hydrocarbons (δ13C), Rock-Eval pyrolysis, and elemental analysis. The positive synergetic effect during co-pyrolysis of lignite/HDPE mixture was observed at temperatures ≥450 °C, with the greatest being at 500 °C. The highest yield of liquid co-pyrolysis products with a similar composition to that of crude oils is also noticed at 500 °C. The yields of liquid and gaseous products and quality of pyrolytic products obtained by co-pyrolysis of lignite/HDPE mixture are notably improved compared with pyrolysis of lignite alone. On the other hand, data obtained from pyrolysis of HDPE alone indicate that it cannot be concurrent to well-developed catalytic thermal processes for polymer recycling. However, concerning the huge amount of produced HDPE, at least part of this plastic material can be reused for advanced thermal treatment of lignite, particularly in countries where this low-rank coal represents the main source of energy.",
publisher = "MDPI",
journal = "Polymers",
title = "Study of the synergetic effect of co-pyrolysis of lignite and high-density polyethylene aiming to improve utilization of low-rank coal",
volume = "13",
number = "5",
pages = "759",
doi = "10.3390/polym13050759"
}

Kojić, I., Bechtel, A., Aleksić, N., Životić, D. R., Trifunović, S. S., Gajica, G.,& Stojanović, K. A.. (2021). Study of the synergetic effect of co-pyrolysis of lignite and high-density polyethylene aiming to improve utilization of low-rank coal. in Polymers
MDPI., 13(5), 759.
https://doi.org/10.3390/polym13050759

Kojić I, Bechtel A, Aleksić N, Životić DR, Trifunović SS, Gajica G, Stojanović KA. Study of the synergetic effect of co-pyrolysis of lignite and high-density polyethylene aiming to improve utilization of low-rank coal. in Polymers. 2021;13(5):759.
doi:10.3390/polym13050759 .

Kojić, Ivan, Bechtel, Achim, Aleksić, Nikoleta, Životić, Dragana R., Trifunović, Snežana S., Gajica, Gordana, Stojanović, Ksenija A., "Study of the synergetic effect of co-pyrolysis of lignite and high-density polyethylene aiming to improve utilization of low-rank coal" in Polymers, 13, no. 5 (2021):759,
https://doi.org/10.3390/polym13050759 . .

TY  - DATA
AU  - Kojić, Ivan
AU  - Bechtel, Achim
AU  - Aleksić, Nikoleta
AU  - Životić, Dragana R.
AU  - Trifunović, Snežana S.
AU  - Gajica, Gordana
AU  - Stojanović, Ksenija A.
PY  - 2021
UR  - https://www.mdpi.com/2073-4360/13/5/759
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/4398
PB  - MDPI
T2  - Polymers
T1  - Supplementary data for the article: Kojić, I.; Bechtel, A.; Aleksić, N.; Životić, D.; Trifunović, S.; Gajica, G.; Stojanović, K. Study of the Synergetic Effect of Co-Pyrolysis of Lignite and High-Density Polyethylene Aiming to Improve Utilization of Low-Rank Coal. Polymers 2021, 13 (5), 759. https://doi.org/10.3390/polym13050759.
UR  - https://hdl.handle.net/21.15107/rcub_cherry_4398
ER  - 

@misc{
author = "Kojić, Ivan and Bechtel, Achim and Aleksić, Nikoleta and Životić, Dragana R. and Trifunović, Snežana S. and Gajica, Gordana and Stojanović, Ksenija A.",
year = "2021",
publisher = "MDPI",
journal = "Polymers",
title = "Supplementary data for the article: Kojić, I.; Bechtel, A.; Aleksić, N.; Životić, D.; Trifunović, S.; Gajica, G.; Stojanović, K. Study of the Synergetic Effect of Co-Pyrolysis of Lignite and High-Density Polyethylene Aiming to Improve Utilization of Low-Rank Coal. Polymers 2021, 13 (5), 759. https://doi.org/10.3390/polym13050759.",
url = "https://hdl.handle.net/21.15107/rcub_cherry_4398"
}

Kojić, I., Bechtel, A., Aleksić, N., Životić, D. R., Trifunović, S. S., Gajica, G.,& Stojanović, K. A.. (2021). Supplementary data for the article: Kojić, I.; Bechtel, A.; Aleksić, N.; Životić, D.; Trifunović, S.; Gajica, G.; Stojanović, K. Study of the Synergetic Effect of Co-Pyrolysis of Lignite and High-Density Polyethylene Aiming to Improve Utilization of Low-Rank Coal. Polymers 2021, 13 (5), 759. https://doi.org/10.3390/polym13050759.. in Polymers
MDPI..
https://hdl.handle.net/21.15107/rcub_cherry_4398

Kojić I, Bechtel A, Aleksić N, Životić DR, Trifunović SS, Gajica G, Stojanović KA. Supplementary data for the article: Kojić, I.; Bechtel, A.; Aleksić, N.; Životić, D.; Trifunović, S.; Gajica, G.; Stojanović, K. Study of the Synergetic Effect of Co-Pyrolysis of Lignite and High-Density Polyethylene Aiming to Improve Utilization of Low-Rank Coal. Polymers 2021, 13 (5), 759. https://doi.org/10.3390/polym13050759.. in Polymers. 2021;.
https://hdl.handle.net/21.15107/rcub_cherry_4398 .

Kojić, Ivan, Bechtel, Achim, Aleksić, Nikoleta, Životić, Dragana R., Trifunović, Snežana S., Gajica, Gordana, Stojanović, Ksenija A., "Supplementary data for the article: Kojić, I.; Bechtel, A.; Aleksić, N.; Životić, D.; Trifunović, S.; Gajica, G.; Stojanović, K. Study of the Synergetic Effect of Co-Pyrolysis of Lignite and High-Density Polyethylene Aiming to Improve Utilization of Low-Rank Coal. Polymers 2021, 13 (5), 759. https://doi.org/10.3390/polym13050759." in Polymers (2021),
https://hdl.handle.net/21.15107/rcub_cherry_4398 .

TY  - JOUR
AU  - Nytoft, Hans Peter
AU  - Kildahl-Andersen, Geir
AU  - Lindström, Sofie
AU  - Rise, Frode
AU  - Bechtel, Achim
AU  - Mitrović, Danica D.
AU  - Đoković, Nataša
AU  - Životić, Dragana R.
AU  - Stojanović, Ksenija A.
PY  - 2019
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/2811
AB  - Two previously unidentified dehydroabietane isomers were isolated from Miocene Serbian
lignite and Rhaetian (Late Triassic) coaly mudstones from South Sweden and characterized using
NMR-spectroscopy as cis- and trans-dehydroicetexane. Both have a 9(10→20)-abeo-abietane or
icetexane skeleton consisting of a 6-7-6 tricyclic framework with seven carbons in ring B instead of
the usual six in common diterpanes of the abietane-type. Dehydroicetexanes can be detected using GC-MS-MS in m/z 270 → 146 chromatograms without interference from dehydroabietane or other isomers. Dehydroicetexanes are often abundant in high latitude coals and mudstones ranging fromTriassic to Miocene, and in high latitude oils (Canada and Greenland) sourced from terrigenous organic matter. The trans/(cis+ trans) dehydroicetexane ratio is low in immature sediments, but usually around 0.83 in oils and mature sediments with vitrinite reflectance (%Rr) above 0.5 suggesting an equilibrium from the start of the oil window. Dehydroicetexanes are more stable than dehydroabietane and some oils, rich in dehydroicetexanes, contain no dehydroabietane. Precursors could be plant diterpenoids having the icetexane structure, which have been known for more than 40 years and isolated from a variety of higher plant sources, including some angiosperms. Many of the relatively simple icetexanes were isolated for the first time from Chamaecyparis pisifera and related species where they seem to be particularly abundant, suggesting that dehydroicetaxanes may be used as markers for the genus Chamaecyparis or for Cupressoideae in general.
PB  - Elsevier
T2  - Organic Geochemistry
T1  - Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae
DO  - 10.1016/j.orggeochem.2019.01.001
ER  - 

@article{
author = "Nytoft, Hans Peter and Kildahl-Andersen, Geir and Lindström, Sofie and Rise, Frode and Bechtel, Achim and Mitrović, Danica D. and Đoković, Nataša and Životić, Dragana R. and Stojanović, Ksenija A.",
year = "2019",
abstract = "Two previously unidentified dehydroabietane isomers were isolated from Miocene Serbian
lignite and Rhaetian (Late Triassic) coaly mudstones from South Sweden and characterized using
NMR-spectroscopy as cis- and trans-dehydroicetexane. Both have a 9(10→20)-abeo-abietane or
icetexane skeleton consisting of a 6-7-6 tricyclic framework with seven carbons in ring B instead of
the usual six in common diterpanes of the abietane-type. Dehydroicetexanes can be detected using GC-MS-MS in m/z 270 → 146 chromatograms without interference from dehydroabietane or other isomers. Dehydroicetexanes are often abundant in high latitude coals and mudstones ranging fromTriassic to Miocene, and in high latitude oils (Canada and Greenland) sourced from terrigenous organic matter. The trans/(cis+ trans) dehydroicetexane ratio is low in immature sediments, but usually around 0.83 in oils and mature sediments with vitrinite reflectance (%Rr) above 0.5 suggesting an equilibrium from the start of the oil window. Dehydroicetexanes are more stable than dehydroabietane and some oils, rich in dehydroicetexanes, contain no dehydroabietane. Precursors could be plant diterpenoids having the icetexane structure, which have been known for more than 40 years and isolated from a variety of higher plant sources, including some angiosperms. Many of the relatively simple icetexanes were isolated for the first time from Chamaecyparis pisifera and related species where they seem to be particularly abundant, suggesting that dehydroicetaxanes may be used as markers for the genus Chamaecyparis or for Cupressoideae in general.",
publisher = "Elsevier",
journal = "Organic Geochemistry",
title = "Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae",
doi = "10.1016/j.orggeochem.2019.01.001"
}

Nytoft, H. P., Kildahl-Andersen, G., Lindström, S., Rise, F., Bechtel, A., Mitrović, D. D., Đoković, N., Životić, D. R.,& Stojanović, K. A.. (2019). Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae. in Organic Geochemistry
Elsevier..
https://doi.org/10.1016/j.orggeochem.2019.01.001

Nytoft HP, Kildahl-Andersen G, Lindström S, Rise F, Bechtel A, Mitrović DD, Đoković N, Životić DR, Stojanović KA. Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae. in Organic Geochemistry. 2019;.
doi:10.1016/j.orggeochem.2019.01.001 .

Nytoft, Hans Peter, Kildahl-Andersen, Geir, Lindström, Sofie, Rise, Frode, Bechtel, Achim, Mitrović, Danica D., Đoković, Nataša, Životić, Dragana R., Stojanović, Ksenija A., "Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae" in Organic Geochemistry (2019),
https://doi.org/10.1016/j.orggeochem.2019.01.001 . .

TY  - JOUR
AU  - Nytoft, Hans Peter
AU  - Kildahl-Andersen, Geir
AU  - Lindström, Sofie
AU  - Rise, Frode
AU  - Bechtel, Achim
AU  - Mitrović, Danica D.
AU  - Đoković, Nataša
AU  - Životić, Dragana R.
AU  - Stojanović, Ksenija A.
PY  - 2019
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/2846
AB  - Two previously unidentified dehydroabietane isomers were isolated from Miocene Serbian lignite and Rhaetian (Late Triassic) coaly mudstones from South Sweden and characterized using NMR-spectroscopy as cis- and trans-dehydroicetexane. Both have a 9(10 → 20)-abeo-abietane or icetexane skeleton, consisting of a 6-7-6 tricyclic framework with seven carbons in ring B instead of the usual six in common diterpanes of the abietane-type. Dehydroicetexanes can be detected using GC-MS-MS in m/z 270 → 146 chromatograms without interference from dehydroabietane or other isomers. Dehydroicetexanes are often abundant in high latitude coals and mudstones ranging from Triassic to Miocene, and in high latitude oils (Canada and Greenland) sourced from terrigenous organic matter. The trans/(cis + trans) dehydroicetexane ratio is low in immature sediments, but usually around 0.83 in oils and mature sediments with vitrinite reflectance (%R r ) above 0.5, suggesting an equilibrium from the start of the oil window. Dehydroicetexanes are more stable than dehydroabietane and some oils, rich in dehydroicetexanes, contain no dehydroabietane. Precursors could be plant diterpenoids having the icetexane structure, which have been known for more than 40 years and isolated from a variety of higher plant sources, including some angiosperms. Many of the relatively simple icetexanes were isolated for the first time from Chamaecyparis pisifera and related species where they seem to be particularly abundant, suggesting that dehydroicetexanes may be used as markers for the genus Chamaecyparis or for Cupressoideae in general.
PB  - Elsevier
T2  - Organic Geochemistry
T1  - Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae
VL  - 129
SP  - 14
EP  - 23
DO  - 10.1016/j.orggeochem.2019.01.001
ER  - 

@article{
author = "Nytoft, Hans Peter and Kildahl-Andersen, Geir and Lindström, Sofie and Rise, Frode and Bechtel, Achim and Mitrović, Danica D. and Đoković, Nataša and Životić, Dragana R. and Stojanović, Ksenija A.",
year = "2019",
abstract = "Two previously unidentified dehydroabietane isomers were isolated from Miocene Serbian lignite and Rhaetian (Late Triassic) coaly mudstones from South Sweden and characterized using NMR-spectroscopy as cis- and trans-dehydroicetexane. Both have a 9(10 → 20)-abeo-abietane or icetexane skeleton, consisting of a 6-7-6 tricyclic framework with seven carbons in ring B instead of the usual six in common diterpanes of the abietane-type. Dehydroicetexanes can be detected using GC-MS-MS in m/z 270 → 146 chromatograms without interference from dehydroabietane or other isomers. Dehydroicetexanes are often abundant in high latitude coals and mudstones ranging from Triassic to Miocene, and in high latitude oils (Canada and Greenland) sourced from terrigenous organic matter. The trans/(cis + trans) dehydroicetexane ratio is low in immature sediments, but usually around 0.83 in oils and mature sediments with vitrinite reflectance (%R r ) above 0.5, suggesting an equilibrium from the start of the oil window. Dehydroicetexanes are more stable than dehydroabietane and some oils, rich in dehydroicetexanes, contain no dehydroabietane. Precursors could be plant diterpenoids having the icetexane structure, which have been known for more than 40 years and isolated from a variety of higher plant sources, including some angiosperms. Many of the relatively simple icetexanes were isolated for the first time from Chamaecyparis pisifera and related species where they seem to be particularly abundant, suggesting that dehydroicetexanes may be used as markers for the genus Chamaecyparis or for Cupressoideae in general.",
publisher = "Elsevier",
journal = "Organic Geochemistry",
title = "Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae",
volume = "129",
pages = "14-23",
doi = "10.1016/j.orggeochem.2019.01.001"
}

Nytoft, H. P., Kildahl-Andersen, G., Lindström, S., Rise, F., Bechtel, A., Mitrović, D. D., Đoković, N., Životić, D. R.,& Stojanović, K. A.. (2019). Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae. in Organic Geochemistry
Elsevier., 129, 14-23.
https://doi.org/10.1016/j.orggeochem.2019.01.001

Nytoft HP, Kildahl-Andersen G, Lindström S, Rise F, Bechtel A, Mitrović DD, Đoković N, Životić DR, Stojanović KA. Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae. in Organic Geochemistry. 2019;129:14-23.
doi:10.1016/j.orggeochem.2019.01.001 .

Nytoft, Hans Peter, Kildahl-Andersen, Geir, Lindström, Sofie, Rise, Frode, Bechtel, Achim, Mitrović, Danica D., Đoković, Nataša, Životić, Dragana R., Stojanović, Ksenija A., "Dehydroicetexanes in sediments and crude oils: Possible markers for Cupressoideae" in Organic Geochemistry, 129 (2019):14-23,
https://doi.org/10.1016/j.orggeochem.2019.01.001 . .

TY  - CONF
AU  - Mitrović, Danica D.
AU  - Đoković, Nataša
AU  - Životić, Dragana R.
AU  - Obradović, Marko O.
AU  - Bechtel, Achim
AU  - Stojanović, K.
PY  - 2019
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/3823
PB  - European Association of Geoscientists and Engineers, EAGE
C3  - 29th International Meeting on Organic Geochemistry, IMOG 2019
T1  - Maceral and biomarker composition of lignite lithotypes - Implications on palaeoenvironment and grindability properties
DO  - 10.3997/2214-4609.201902880
ER  - 

@conference{
author = "Mitrović, Danica D. and Đoković, Nataša and Životić, Dragana R. and Obradović, Marko O. and Bechtel, Achim and Stojanović, K.",
year = "2019",
publisher = "European Association of Geoscientists and Engineers, EAGE",
journal = "29th International Meeting on Organic Geochemistry, IMOG 2019",
title = "Maceral and biomarker composition of lignite lithotypes - Implications on palaeoenvironment and grindability properties",
doi = "10.3997/2214-4609.201902880"
}

Mitrović, D. D., Đoković, N., Životić, D. R., Obradović, M. O., Bechtel, A.,& Stojanović, K.. (2019). Maceral and biomarker composition of lignite lithotypes - Implications on palaeoenvironment and grindability properties. in 29th International Meeting on Organic Geochemistry, IMOG 2019
European Association of Geoscientists and Engineers, EAGE..
https://doi.org/10.3997/2214-4609.201902880

Mitrović DD, Đoković N, Životić DR, Obradović MO, Bechtel A, Stojanović K. Maceral and biomarker composition of lignite lithotypes - Implications on palaeoenvironment and grindability properties. in 29th International Meeting on Organic Geochemistry, IMOG 2019. 2019;.
doi:10.3997/2214-4609.201902880 .

Mitrović, Danica D., Đoković, Nataša, Životić, Dragana R., Obradović, Marko O., Bechtel, Achim, Stojanović, K., "Maceral and biomarker composition of lignite lithotypes - Implications on palaeoenvironment and grindability properties" in 29th International Meeting on Organic Geochemistry, IMOG 2019 (2019),
https://doi.org/10.3997/2214-4609.201902880 . .

TY  - JOUR
AU  - Bechtel, Achim
AU  - Oberauer, Klaus
AU  - Kostić, Aleksandar Ž.
AU  - Gratzer, Reinhard
AU  - Milisavljević, Vladimir
AU  - Aleksić, Nikoleta
AU  - Stojanović, Ksenija A.
AU  - Gross, Doris
AU  - Sachsenhofer, Reinhard F.
PY  - 2018
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/2573
AB  - The most prolific oil shale deposit in Serbia is located in the Aleksinac Basin and is assigned to the Lower Miocene. Depositional environments and hydrocarbon potential were assessed for the Aleksinac oil shale and coal layers through bulk geochemical, organic petrographical, biomarker, and carbon isotope data from core samples from a single well. Maturity parameters (vitrinite reflectance, T-max, biomarker isomerisation ratios) prove that the organic matter (OM) is immature. A lower lacustrine oil shale sequence is comprised of alternating sandstone and clay-rich rocks and some thin coal beds, indicating strong variations in depositional environment. This stratum is covered with thick sandstone (50 m) terminated by the main 4 m thick coal seam that was deposited in a low-lying mire, as evidenced by high total sulfur and mineral matrix contents. The plant input was dominated by angiosperms. A relative rise in water level led to the drowning of the swamp and to the deposition of a 60 m thick upper oil shale in a lacustrine environment. The OM of the oil shale is dominated by kerogen Type I (lamalginite). Biomarker data suggest a stratified water column that likely formed due to differences in salinity. The stratified water column led to a strictly anoxic environment and photic zone euxinia in a mesosalinar, hydrologically closed lake, which enabled the accumulation of uncommonly high amounts of organic material (average TOC: 18.0 wt%) with excellent preservation (average HI: 743 mg HC/g TOC). (c) 2017 Elsevier Ltd. All rights reserved.
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - Organic Geochemistry
T1  - Depositional environment and hydrocarbon source potential of the Lower Miocene oil shale deposit in the Aleksinac Basin (Serbia)
VL  - 115
SP  - 93
EP  - 112
DO  - 10.1016/j.orggeochem.2017.10.009
ER  - 

@article{
author = "Bechtel, Achim and Oberauer, Klaus and Kostić, Aleksandar Ž. and Gratzer, Reinhard and Milisavljević, Vladimir and Aleksić, Nikoleta and Stojanović, Ksenija A. and Gross, Doris and Sachsenhofer, Reinhard F.",
year = "2018",
abstract = "The most prolific oil shale deposit in Serbia is located in the Aleksinac Basin and is assigned to the Lower Miocene. Depositional environments and hydrocarbon potential were assessed for the Aleksinac oil shale and coal layers through bulk geochemical, organic petrographical, biomarker, and carbon isotope data from core samples from a single well. Maturity parameters (vitrinite reflectance, T-max, biomarker isomerisation ratios) prove that the organic matter (OM) is immature. A lower lacustrine oil shale sequence is comprised of alternating sandstone and clay-rich rocks and some thin coal beds, indicating strong variations in depositional environment. This stratum is covered with thick sandstone (50 m) terminated by the main 4 m thick coal seam that was deposited in a low-lying mire, as evidenced by high total sulfur and mineral matrix contents. The plant input was dominated by angiosperms. A relative rise in water level led to the drowning of the swamp and to the deposition of a 60 m thick upper oil shale in a lacustrine environment. The OM of the oil shale is dominated by kerogen Type I (lamalginite). Biomarker data suggest a stratified water column that likely formed due to differences in salinity. The stratified water column led to a strictly anoxic environment and photic zone euxinia in a mesosalinar, hydrologically closed lake, which enabled the accumulation of uncommonly high amounts of organic material (average TOC: 18.0 wt%) with excellent preservation (average HI: 743 mg HC/g TOC). (c) 2017 Elsevier Ltd. All rights reserved.",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "Organic Geochemistry",
title = "Depositional environment and hydrocarbon source potential of the Lower Miocene oil shale deposit in the Aleksinac Basin (Serbia)",
volume = "115",
pages = "93-112",
doi = "10.1016/j.orggeochem.2017.10.009"
}

Bechtel, A., Oberauer, K., Kostić, A. Ž., Gratzer, R., Milisavljević, V., Aleksić, N., Stojanović, K. A., Gross, D.,& Sachsenhofer, R. F.. (2018). Depositional environment and hydrocarbon source potential of the Lower Miocene oil shale deposit in the Aleksinac Basin (Serbia). in Organic Geochemistry
Pergamon-Elsevier Science Ltd, Oxford., 115, 93-112.
https://doi.org/10.1016/j.orggeochem.2017.10.009

Bechtel A, Oberauer K, Kostić AŽ, Gratzer R, Milisavljević V, Aleksić N, Stojanović KA, Gross D, Sachsenhofer RF. Depositional environment and hydrocarbon source potential of the Lower Miocene oil shale deposit in the Aleksinac Basin (Serbia). in Organic Geochemistry. 2018;115:93-112.
doi:10.1016/j.orggeochem.2017.10.009 .

Bechtel, Achim, Oberauer, Klaus, Kostić, Aleksandar Ž., Gratzer, Reinhard, Milisavljević, Vladimir, Aleksić, Nikoleta, Stojanović, Ksenija A., Gross, Doris, Sachsenhofer, Reinhard F., "Depositional environment and hydrocarbon source potential of the Lower Miocene oil shale deposit in the Aleksinac Basin (Serbia)" in Organic Geochemistry, 115 (2018):93-112,
https://doi.org/10.1016/j.orggeochem.2017.10.009 . .

TY  - JOUR
AU  - Bechtel, Achim
AU  - Oberauer, Klaus
AU  - Kostić, Aleksandar Ž.
AU  - Gratzer, Reinhard
AU  - Milisavljević, Vladimir
AU  - Aleksić, Nikoleta
AU  - Stojanović, Ksenija A.
AU  - Gross, Doris
AU  - Sachsenhofer, Reinhard F.
PY  - 2018
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/3031
AB  - The most prolific oil shale deposit in Serbia is located in the Aleksinac Basin and is assigned to the Lower Miocene. Depositional environments and hydrocarbon potential were assessed for the Aleksinac oil shale and coal layers through bulk geochemical, organic petrographical, biomarker, and carbon isotope data from core samples from a single well. Maturity parameters (vitrinite reflectance, T-max, biomarker isomerisation ratios) prove that the organic matter (OM) is immature. A lower lacustrine oil shale sequence is comprised of alternating sandstone and clay-rich rocks and some thin coal beds, indicating strong variations in depositional environment. This stratum is covered with thick sandstone (50 m) terminated by the main 4 m thick coal seam that was deposited in a low-lying mire, as evidenced by high total sulfur and mineral matrix contents. The plant input was dominated by angiosperms. A relative rise in water level led to the drowning of the swamp and to the deposition of a 60 m thick upper oil shale in a lacustrine environment. The OM of the oil shale is dominated by kerogen Type I (lamalginite). Biomarker data suggest a stratified water column that likely formed due to differences in salinity. The stratified water column led to a strictly anoxic environment and photic zone euxinia in a mesosalinar, hydrologically closed lake, which enabled the accumulation of uncommonly high amounts of organic material (average TOC: 18.0 wt%) with excellent preservation (average HI: 743 mg HC/g TOC). (c) 2017 Elsevier Ltd. All rights reserved.
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - Organic Geochemistry
T1  - Depositional environment and hydrocarbon source potential of the Lower Miocene oil shale deposit in the Aleksinac Basin (Serbia)
VL  - 115
SP  - 93
EP  - 112
DO  - 10.1016/j.orggeochem.2017.10.009
ER  - 

@article{
author = "Bechtel, Achim and Oberauer, Klaus and Kostić, Aleksandar Ž. and Gratzer, Reinhard and Milisavljević, Vladimir and Aleksić, Nikoleta and Stojanović, Ksenija A. and Gross, Doris and Sachsenhofer, Reinhard F.",
year = "2018",
abstract = "The most prolific oil shale deposit in Serbia is located in the Aleksinac Basin and is assigned to the Lower Miocene. Depositional environments and hydrocarbon potential were assessed for the Aleksinac oil shale and coal layers through bulk geochemical, organic petrographical, biomarker, and carbon isotope data from core samples from a single well. Maturity parameters (vitrinite reflectance, T-max, biomarker isomerisation ratios) prove that the organic matter (OM) is immature. A lower lacustrine oil shale sequence is comprised of alternating sandstone and clay-rich rocks and some thin coal beds, indicating strong variations in depositional environment. This stratum is covered with thick sandstone (50 m) terminated by the main 4 m thick coal seam that was deposited in a low-lying mire, as evidenced by high total sulfur and mineral matrix contents. The plant input was dominated by angiosperms. A relative rise in water level led to the drowning of the swamp and to the deposition of a 60 m thick upper oil shale in a lacustrine environment. The OM of the oil shale is dominated by kerogen Type I (lamalginite). Biomarker data suggest a stratified water column that likely formed due to differences in salinity. The stratified water column led to a strictly anoxic environment and photic zone euxinia in a mesosalinar, hydrologically closed lake, which enabled the accumulation of uncommonly high amounts of organic material (average TOC: 18.0 wt%) with excellent preservation (average HI: 743 mg HC/g TOC). (c) 2017 Elsevier Ltd. All rights reserved.",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "Organic Geochemistry",
title = "Depositional environment and hydrocarbon source potential of the Lower Miocene oil shale deposit in the Aleksinac Basin (Serbia)",
volume = "115",
pages = "93-112",
doi = "10.1016/j.orggeochem.2017.10.009"
}

Bechtel, A., Oberauer, K., Kostić, A. Ž., Gratzer, R., Milisavljević, V., Aleksić, N., Stojanović, K. A., Gross, D.,& Sachsenhofer, R. F.. (2018). Depositional environment and hydrocarbon source potential of the Lower Miocene oil shale deposit in the Aleksinac Basin (Serbia). in Organic Geochemistry
Pergamon-Elsevier Science Ltd, Oxford., 115, 93-112.
https://doi.org/10.1016/j.orggeochem.2017.10.009

Bechtel A, Oberauer K, Kostić AŽ, Gratzer R, Milisavljević V, Aleksić N, Stojanović KA, Gross D, Sachsenhofer RF. Depositional environment and hydrocarbon source potential of the Lower Miocene oil shale deposit in the Aleksinac Basin (Serbia). in Organic Geochemistry. 2018;115:93-112.
doi:10.1016/j.orggeochem.2017.10.009 .

Bechtel, Achim, Oberauer, Klaus, Kostić, Aleksandar Ž., Gratzer, Reinhard, Milisavljević, Vladimir, Aleksić, Nikoleta, Stojanović, Ksenija A., Gross, Doris, Sachsenhofer, Reinhard F., "Depositional environment and hydrocarbon source potential of the Lower Miocene oil shale deposit in the Aleksinac Basin (Serbia)" in Organic Geochemistry, 115 (2018):93-112,
https://doi.org/10.1016/j.orggeochem.2017.10.009 . .

TY  - JOUR
AU  - Kojić, Ivan
AU  - Bechtel, Achim
AU  - Kittinger, Friedrich
AU  - Stevanović, Nikola R.
AU  - Obradović, Marko
AU  - Stojanović, Ksenija A.
PY  - 2018
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/2201
AB  - Pyrolysis of high density polyethylene (HDPE) in the open system was studied. A plastic bag for food packing was used as a source of HDPE. Pyrolysis was performed at temperatures of 400, 450 and 500 degrees C, which were chosen based on thermogravimetric analysis. The HDPE pyrolysis yielded liquid, gaseous and solid products. Temperature rise resulted in the increase of conversion of HDPE into liquid and gaseous products. The main constituents of liquid pyrolysates are 1-n-alkenes, n-alkanes and terminal n-dienes. The composition of liquid products indicates that the performed pyrolysis of HDPE could not serve as a standalone operation for the production of gasoline or diesel, but preferably as a pre-treatment to yield a product to be blended into a refinery or petrochemical feed stream. The advantage of a liquid pyrolysate in comparison to crude oil is the extremely low content of aromatic hydrocarbons and the absence of polar compounds. The gaseous products have desirable composition and consist mainly of methane and ethene. The solid residues do not produce ash by combustion and have high calorific values. Co-pyrolysis of HDPE with mineral-rich lignite indicated positive synergetic effect at 450 and 500 degrees C, which is reflected through the increased experimental yields of liquid and gaseous products in comparison to theoretical ones.
PB  - Serbian Chemical Soc, Belgrade
T2  - Journal of the Serbian Chemical Society
T1  - Study of pyrolysis of high density polyethylene in the open system and estimation of its capability for co-pyrolysis with lignite
VL  - 83
IS  - 7-8
SP  - 923
EP  - 940
DO  - 10.2298/JSC171215027K
ER  - 

@article{
author = "Kojić, Ivan and Bechtel, Achim and Kittinger, Friedrich and Stevanović, Nikola R. and Obradović, Marko and Stojanović, Ksenija A.",
year = "2018",
abstract = "Pyrolysis of high density polyethylene (HDPE) in the open system was studied. A plastic bag for food packing was used as a source of HDPE. Pyrolysis was performed at temperatures of 400, 450 and 500 degrees C, which were chosen based on thermogravimetric analysis. The HDPE pyrolysis yielded liquid, gaseous and solid products. Temperature rise resulted in the increase of conversion of HDPE into liquid and gaseous products. The main constituents of liquid pyrolysates are 1-n-alkenes, n-alkanes and terminal n-dienes. The composition of liquid products indicates that the performed pyrolysis of HDPE could not serve as a standalone operation for the production of gasoline or diesel, but preferably as a pre-treatment to yield a product to be blended into a refinery or petrochemical feed stream. The advantage of a liquid pyrolysate in comparison to crude oil is the extremely low content of aromatic hydrocarbons and the absence of polar compounds. The gaseous products have desirable composition and consist mainly of methane and ethene. The solid residues do not produce ash by combustion and have high calorific values. Co-pyrolysis of HDPE with mineral-rich lignite indicated positive synergetic effect at 450 and 500 degrees C, which is reflected through the increased experimental yields of liquid and gaseous products in comparison to theoretical ones.",
publisher = "Serbian Chemical Soc, Belgrade",
journal = "Journal of the Serbian Chemical Society",
title = "Study of pyrolysis of high density polyethylene in the open system and estimation of its capability for co-pyrolysis with lignite",
volume = "83",
number = "7-8",
pages = "923-940",
doi = "10.2298/JSC171215027K"
}

Kojić, I., Bechtel, A., Kittinger, F., Stevanović, N. R., Obradović, M.,& Stojanović, K. A.. (2018). Study of pyrolysis of high density polyethylene in the open system and estimation of its capability for co-pyrolysis with lignite. in Journal of the Serbian Chemical Society
Serbian Chemical Soc, Belgrade., 83(7-8), 923-940.
https://doi.org/10.2298/JSC171215027K

Kojić I, Bechtel A, Kittinger F, Stevanović NR, Obradović M, Stojanović KA. Study of pyrolysis of high density polyethylene in the open system and estimation of its capability for co-pyrolysis with lignite. in Journal of the Serbian Chemical Society. 2018;83(7-8):923-940.
doi:10.2298/JSC171215027K .

Kojić, Ivan, Bechtel, Achim, Kittinger, Friedrich, Stevanović, Nikola R., Obradović, Marko, Stojanović, Ksenija A., "Study of pyrolysis of high density polyethylene in the open system and estimation of its capability for co-pyrolysis with lignite" in Journal of the Serbian Chemical Society, 83, no. 7-8 (2018):923-940,
https://doi.org/10.2298/JSC171215027K . .

TY  - DATA
AU  - Kojić, Ivan
AU  - Bechtel, Achim
AU  - Kittinger, Friedrich
AU  - Stevanović, Nikola R.
AU  - Obradović, Marko
AU  - Stojanović, Ksenija A.
PY  - 2018
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/3306
PB  - Serbian Chemical Soc, Belgrade
T2  - Journal of the Serbian Chemical Society
T1  - Supplementary data for the article: Kojic, I.; Bechtel, A.; Kittinger, F.; Stevanovic, N.; Obradovic, M.; Stojanovic, K. Study of Pyrolysis of High Density Polyethylene in the Open System and Estimation of Its Capability for Co-Pyrolysis with Lignite. J. Serb. Chem. Soc. 2018, 83 (7–8), 923–940. https://doi.org/10.2298/JSC171215027K
UR  - https://hdl.handle.net/21.15107/rcub_cherry_3306
ER  - 

@misc{
author = "Kojić, Ivan and Bechtel, Achim and Kittinger, Friedrich and Stevanović, Nikola R. and Obradović, Marko and Stojanović, Ksenija A.",
year = "2018",
publisher = "Serbian Chemical Soc, Belgrade",
journal = "Journal of the Serbian Chemical Society",
title = "Supplementary data for the article: Kojic, I.; Bechtel, A.; Kittinger, F.; Stevanovic, N.; Obradovic, M.; Stojanovic, K. Study of Pyrolysis of High Density Polyethylene in the Open System and Estimation of Its Capability for Co-Pyrolysis with Lignite. J. Serb. Chem. Soc. 2018, 83 (7–8), 923–940. https://doi.org/10.2298/JSC171215027K",
url = "https://hdl.handle.net/21.15107/rcub_cherry_3306"
}

Kojić, I., Bechtel, A., Kittinger, F., Stevanović, N. R., Obradović, M.,& Stojanović, K. A.. (2018). Supplementary data for the article: Kojic, I.; Bechtel, A.; Kittinger, F.; Stevanovic, N.; Obradovic, M.; Stojanovic, K. Study of Pyrolysis of High Density Polyethylene in the Open System and Estimation of Its Capability for Co-Pyrolysis with Lignite. J. Serb. Chem. Soc. 2018, 83 (7–8), 923–940. https://doi.org/10.2298/JSC171215027K. in Journal of the Serbian Chemical Society
Serbian Chemical Soc, Belgrade..
https://hdl.handle.net/21.15107/rcub_cherry_3306

Kojić I, Bechtel A, Kittinger F, Stevanović NR, Obradović M, Stojanović KA. Supplementary data for the article: Kojic, I.; Bechtel, A.; Kittinger, F.; Stevanovic, N.; Obradovic, M.; Stojanovic, K. Study of Pyrolysis of High Density Polyethylene in the Open System and Estimation of Its Capability for Co-Pyrolysis with Lignite. J. Serb. Chem. Soc. 2018, 83 (7–8), 923–940. https://doi.org/10.2298/JSC171215027K. in Journal of the Serbian Chemical Society. 2018;.
https://hdl.handle.net/21.15107/rcub_cherry_3306 .

Kojić, Ivan, Bechtel, Achim, Kittinger, Friedrich, Stevanović, Nikola R., Obradović, Marko, Stojanović, Ksenija A., "Supplementary data for the article: Kojic, I.; Bechtel, A.; Kittinger, F.; Stevanovic, N.; Obradovic, M.; Stojanovic, K. Study of Pyrolysis of High Density Polyethylene in the Open System and Estimation of Its Capability for Co-Pyrolysis with Lignite. J. Serb. Chem. Soc. 2018, 83 (7–8), 923–940. https://doi.org/10.2298/JSC171215027K" in Journal of the Serbian Chemical Society (2018),
https://hdl.handle.net/21.15107/rcub_cherry_3306 .

TY  - JOUR
AU  - Đoković, Nataša
AU  - Mitrović, Danica D.
AU  - Životić, Dragana R.
AU  - Bechtel, Achim
AU  - Sachsenhofer, Reinhard F.
AU  - Stojanović, Ksenija A.
PY  - 2018
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/2077
AB  - The maceral and biomarker characteristics of 4 sublithotypes of xylite-rich coal (SXCs), pale yellow, dark yellow, brown and black, originating from the Kolubara and Kostolac lignite basins were determined. Based on these results, differences in sources and changes of organic matter (OM) resulting in formation of 4 SXCs were established. Conifers (particularly Cupressaceae, Taxodiaceae and Pinacea) had a significant impact on the precursor OM of all SXCs. The contribution of gymnosperm vs. angiosperm vegetation decreased in order pale yellow SXC  gt  dark yellow SXC  gt  brown SXC  gt  black SXC. The distribution of non-hopanoid triterpenoids indicates that change of SXC colour from -yellow to black is associated with reduced input of angiosperm plants from the Betulacea family. Differences in hopane distribution, bitumen content, proportion of short-chain n-alkanes and degree of aromatization of di-and triterpenoids of pale yellow SXC are controlled by microbial communities which took part in the diagenetic alteration of OM. The content of total huminites increased from black to pale yellow SXC, whereas contents of total liptinite and inertinite macerals showed the opposite trend. SXCs differ according to textinite/ulminite ratio, which sharply decreased from pale yellow to black SXC, reflecting increase in gelification of woody tissue. Regarding the composition of liptinite macerals, the SXCs mostly differ according to resinite/liptodetrinite and resinite/suberinite ratios, which are higher in yellow than in brown and black SXC. This result along with values of TOC/N ratio and Carbon Preference Index indicate that the contribution of well preserved woody material, including lignin tissue vs. the impact of epicuticular waxes decreased from yellow to black SXC.
PB  - Slovak Acad Sciences Geological  Inst, Bratislava
T2  - Geologica Carpathica
T1  - Petrographic and biomarker analysis of xylite-rich coal from the Kolubara and Kostolac lignite basins (Pannonian Basin, Serbia)
VL  - 69
IS  - 1
SP  - 51
EP  - 70
DO  - 10.1515/geoca-2018-0004
ER  - 

@article{
author = "Đoković, Nataša and Mitrović, Danica D. and Životić, Dragana R. and Bechtel, Achim and Sachsenhofer, Reinhard F. and Stojanović, Ksenija A.",
year = "2018",
abstract = "The maceral and biomarker characteristics of 4 sublithotypes of xylite-rich coal (SXCs), pale yellow, dark yellow, brown and black, originating from the Kolubara and Kostolac lignite basins were determined. Based on these results, differences in sources and changes of organic matter (OM) resulting in formation of 4 SXCs were established. Conifers (particularly Cupressaceae, Taxodiaceae and Pinacea) had a significant impact on the precursor OM of all SXCs. The contribution of gymnosperm vs. angiosperm vegetation decreased in order pale yellow SXC  gt  dark yellow SXC  gt  brown SXC  gt  black SXC. The distribution of non-hopanoid triterpenoids indicates that change of SXC colour from -yellow to black is associated with reduced input of angiosperm plants from the Betulacea family. Differences in hopane distribution, bitumen content, proportion of short-chain n-alkanes and degree of aromatization of di-and triterpenoids of pale yellow SXC are controlled by microbial communities which took part in the diagenetic alteration of OM. The content of total huminites increased from black to pale yellow SXC, whereas contents of total liptinite and inertinite macerals showed the opposite trend. SXCs differ according to textinite/ulminite ratio, which sharply decreased from pale yellow to black SXC, reflecting increase in gelification of woody tissue. Regarding the composition of liptinite macerals, the SXCs mostly differ according to resinite/liptodetrinite and resinite/suberinite ratios, which are higher in yellow than in brown and black SXC. This result along with values of TOC/N ratio and Carbon Preference Index indicate that the contribution of well preserved woody material, including lignin tissue vs. the impact of epicuticular waxes decreased from yellow to black SXC.",
publisher = "Slovak Acad Sciences Geological  Inst, Bratislava",
journal = "Geologica Carpathica",
title = "Petrographic and biomarker analysis of xylite-rich coal from the Kolubara and Kostolac lignite basins (Pannonian Basin, Serbia)",
volume = "69",
number = "1",
pages = "51-70",
doi = "10.1515/geoca-2018-0004"
}

Đoković, N., Mitrović, D. D., Životić, D. R., Bechtel, A., Sachsenhofer, R. F.,& Stojanović, K. A.. (2018). Petrographic and biomarker analysis of xylite-rich coal from the Kolubara and Kostolac lignite basins (Pannonian Basin, Serbia). in Geologica Carpathica
Slovak Acad Sciences Geological  Inst, Bratislava., 69(1), 51-70.
https://doi.org/10.1515/geoca-2018-0004

Đoković N, Mitrović DD, Životić DR, Bechtel A, Sachsenhofer RF, Stojanović KA. Petrographic and biomarker analysis of xylite-rich coal from the Kolubara and Kostolac lignite basins (Pannonian Basin, Serbia). in Geologica Carpathica. 2018;69(1):51-70.
doi:10.1515/geoca-2018-0004 .

Đoković, Nataša, Mitrović, Danica D., Životić, Dragana R., Bechtel, Achim, Sachsenhofer, Reinhard F., Stojanović, Ksenija A., "Petrographic and biomarker analysis of xylite-rich coal from the Kolubara and Kostolac lignite basins (Pannonian Basin, Serbia)" in Geologica Carpathica, 69, no. 1 (2018):51-70,
https://doi.org/10.1515/geoca-2018-0004 . .

TY  - JOUR
AU  - Đoković, Nataša
AU  - Mitrović, Danica D.
AU  - Životić, Dragana R.
AU  - Bechtel, Achim
AU  - Sachsenhofer, Reinhard F.
AU  - Matic, Vesna
AU  - Glamocanin, Lidija
AU  - Stojanović, Ksenija A.
PY  - 2018
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/2195
AB  - Three Upper Miocene (Pontian) lignite seams are present in the Smederevsko Pomoravlje field (Kostolac Basin, Serbia). The origin of their organic matter (OM), the characteristics of the depositional environment and certain utilisation properties have been evaluated based on petrographic data, bulk organic geochemical parameters, biomarker patterns and their isotope signatures. Moreover, results of isotopic analysis were used for the investigation of the influence of diagenetic aromatisation on delta C-13 signatures of biomarkers. The studied lignites are typical humic coals. The OM of lignites is derived from woody vegetation and herbaceous peat-forming plants, with a strong prevalence of the former. The peat-forming vegetation is dominated by decay resistant conifers, including gymnosperm families Cupressaceae, Taxodiaceae, and Pinaceae. Angiosperms occurred in lower amounts. Minor contribution of ferns, fungi and emergent aquatic macrophyta to the biomass is also evident. Chemoautotrophic- and heterotrophic bacteria played an import role during diagenesis. Diagenetic alterations, associated with change in the number of carbon atoms, influence delta C-13 ratios. Diagenetic aromatisation of di- and non-hopanoid triterpenoids is accompanied with C-13 depletion, whereas aromatisation of hopanoids displays the opposite trend. Peatification proceeded in a fresh water environment under variable, anoxic to slightly oxic redox conditions. The lowermost coal seam III accumulated in a topogenous fresh water peat mire with open water areas, which changed occasionally into a wet forest swamp. This resulted in the deposition of mineral-rich coal. The characteristics of lignite in coal seam II are similar to those of coal seam III. This is supported also by generally similar delta C-13 values of individual biomarkers. Coal seam I is dominated by xylite-rich coal, formed under mesotrophic to ombrotrophic conditions. Rapid flooding of the bogs stopped peat growth in all three coal seams. The ratios of ring-A-degraded and non-degraded aromatic diterpenoids and non-hopanoid triterpenoids, proposed in this study, as well as degree of aromatisation of these biomarkers, reflect changes in the water table. Calorific values of the samples indicate that they meet basic requirements for utilisation in the thermal power plants. None of the lignite samples is suitable for coal briquetting, whereas, based on petrographic data, lignite from coal seam I possesses certain potential for fluidized bed gasification.
PB  - Elsevier Science Bv, Amsterdam
T2  - International Journal of Coal Geology
T1  - Petrographical and organic geochemical study of the lignite from the Smederevsko Pomoravlje field (Kostolac Basin, Serbia)
VL  - 195
SP  - 139
EP  - 171
DO  - 10.1016/j.coal.2018.06.005
ER  - 

@article{
author = "Đoković, Nataša and Mitrović, Danica D. and Životić, Dragana R. and Bechtel, Achim and Sachsenhofer, Reinhard F. and Matic, Vesna and Glamocanin, Lidija and Stojanović, Ksenija A.",
year = "2018",
abstract = "Three Upper Miocene (Pontian) lignite seams are present in the Smederevsko Pomoravlje field (Kostolac Basin, Serbia). The origin of their organic matter (OM), the characteristics of the depositional environment and certain utilisation properties have been evaluated based on petrographic data, bulk organic geochemical parameters, biomarker patterns and their isotope signatures. Moreover, results of isotopic analysis were used for the investigation of the influence of diagenetic aromatisation on delta C-13 signatures of biomarkers. The studied lignites are typical humic coals. The OM of lignites is derived from woody vegetation and herbaceous peat-forming plants, with a strong prevalence of the former. The peat-forming vegetation is dominated by decay resistant conifers, including gymnosperm families Cupressaceae, Taxodiaceae, and Pinaceae. Angiosperms occurred in lower amounts. Minor contribution of ferns, fungi and emergent aquatic macrophyta to the biomass is also evident. Chemoautotrophic- and heterotrophic bacteria played an import role during diagenesis. Diagenetic alterations, associated with change in the number of carbon atoms, influence delta C-13 ratios. Diagenetic aromatisation of di- and non-hopanoid triterpenoids is accompanied with C-13 depletion, whereas aromatisation of hopanoids displays the opposite trend. Peatification proceeded in a fresh water environment under variable, anoxic to slightly oxic redox conditions. The lowermost coal seam III accumulated in a topogenous fresh water peat mire with open water areas, which changed occasionally into a wet forest swamp. This resulted in the deposition of mineral-rich coal. The characteristics of lignite in coal seam II are similar to those of coal seam III. This is supported also by generally similar delta C-13 values of individual biomarkers. Coal seam I is dominated by xylite-rich coal, formed under mesotrophic to ombrotrophic conditions. Rapid flooding of the bogs stopped peat growth in all three coal seams. The ratios of ring-A-degraded and non-degraded aromatic diterpenoids and non-hopanoid triterpenoids, proposed in this study, as well as degree of aromatisation of these biomarkers, reflect changes in the water table. Calorific values of the samples indicate that they meet basic requirements for utilisation in the thermal power plants. None of the lignite samples is suitable for coal briquetting, whereas, based on petrographic data, lignite from coal seam I possesses certain potential for fluidized bed gasification.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "International Journal of Coal Geology",
title = "Petrographical and organic geochemical study of the lignite from the Smederevsko Pomoravlje field (Kostolac Basin, Serbia)",
volume = "195",
pages = "139-171",
doi = "10.1016/j.coal.2018.06.005"
}

Đoković, N., Mitrović, D. D., Životić, D. R., Bechtel, A., Sachsenhofer, R. F., Matic, V., Glamocanin, L.,& Stojanović, K. A.. (2018). Petrographical and organic geochemical study of the lignite from the Smederevsko Pomoravlje field (Kostolac Basin, Serbia). in International Journal of Coal Geology
Elsevier Science Bv, Amsterdam., 195, 139-171.
https://doi.org/10.1016/j.coal.2018.06.005

Đoković N, Mitrović DD, Životić DR, Bechtel A, Sachsenhofer RF, Matic V, Glamocanin L, Stojanović KA. Petrographical and organic geochemical study of the lignite from the Smederevsko Pomoravlje field (Kostolac Basin, Serbia). in International Journal of Coal Geology. 2018;195:139-171.
doi:10.1016/j.coal.2018.06.005 .

Đoković, Nataša, Mitrović, Danica D., Životić, Dragana R., Bechtel, Achim, Sachsenhofer, Reinhard F., Matic, Vesna, Glamocanin, Lidija, Stojanović, Ksenija A., "Petrographical and organic geochemical study of the lignite from the Smederevsko Pomoravlje field (Kostolac Basin, Serbia)" in International Journal of Coal Geology, 195 (2018):139-171,
https://doi.org/10.1016/j.coal.2018.06.005 . .

TY  - JOUR
AU  - Mitrović, Danica D.
AU  - Đoković, Nataša
AU  - Životić, Dragana R.
AU  - Bechtel, Achim
AU  - Cvetković, Olga
AU  - Stojanović, Ksenija A.
PY  - 2017
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/2510
AB  - Four lignite lithotypes (matrix coal, xylite-rich coal, mixture of matrix and mineral-rich coal and mixture of matrix and xylite-rich coal), originating from the Kovin deposit, were investigated in detail. The paper was aimed to determine the main maceral, biomarker and isotopic (delta C-13) characteristics of investigated lithotypes. Based on these results the sources and depositional environment of organic matter in 4 lithotypes were established. These samples were also used as substrates for investigation of the influence of diagenetic alteration on delta C-13 signatures of biomarkers, as well as for assessment of the most convenient utilization for each lithotype. The investigated lithotypes differ in accordance with the composition of huminite macerals. Xylite-rich coal notably distinguishes from other lithotypes beacuse of the highest content of conifer resins vs. epicuticular waxes. The mixture of matrix and mineral-rich coal is characterised by the greatest contribution of algae and fungi and the most intense methanotrophic activity at the time of deposition. In all coal lithotypes diagenetic aromatisation influenced isotopic composition of individual biomarkers. Xylite-rich coal has the poorest grindability properties. However, this coal lithotype is the most suitable for fluidized bed gasification, whereas the mixture of matrix and mineral-rich coal has the lowest applicability for this process. The calorific value decreases in order: xylite-rich coal  gt  matrix coal  gt  mixture of matrix and xylite-rich coal  gt  mixture of matrix and mineral-rich coal. The increase of organic carbon content and calorific value is controlled by the increase of contribution of wood vegetation vs. herbaceous peat-forming plants, as well as by stability of water table during peatification.
PB  - Serbian Chemical Soc, Belgrade
T2  - Journal of the Serbian Chemical Society
T1  - Characterisation of lignite lithotypes from the "Kovin" deposit (Serbia) - Implications from petrographic, biomarker and isotopic analysis
VL  - 82
IS  - 6
SP  - 739
EP  - 754
DO  - 10.2298/JSC161122030M
ER  - 

@article{
author = "Mitrović, Danica D. and Đoković, Nataša and Životić, Dragana R. and Bechtel, Achim and Cvetković, Olga and Stojanović, Ksenija A.",
year = "2017",
abstract = "Four lignite lithotypes (matrix coal, xylite-rich coal, mixture of matrix and mineral-rich coal and mixture of matrix and xylite-rich coal), originating from the Kovin deposit, were investigated in detail. The paper was aimed to determine the main maceral, biomarker and isotopic (delta C-13) characteristics of investigated lithotypes. Based on these results the sources and depositional environment of organic matter in 4 lithotypes were established. These samples were also used as substrates for investigation of the influence of diagenetic alteration on delta C-13 signatures of biomarkers, as well as for assessment of the most convenient utilization for each lithotype. The investigated lithotypes differ in accordance with the composition of huminite macerals. Xylite-rich coal notably distinguishes from other lithotypes beacuse of the highest content of conifer resins vs. epicuticular waxes. The mixture of matrix and mineral-rich coal is characterised by the greatest contribution of algae and fungi and the most intense methanotrophic activity at the time of deposition. In all coal lithotypes diagenetic aromatisation influenced isotopic composition of individual biomarkers. Xylite-rich coal has the poorest grindability properties. However, this coal lithotype is the most suitable for fluidized bed gasification, whereas the mixture of matrix and mineral-rich coal has the lowest applicability for this process. The calorific value decreases in order: xylite-rich coal  gt  matrix coal  gt  mixture of matrix and xylite-rich coal  gt  mixture of matrix and mineral-rich coal. The increase of organic carbon content and calorific value is controlled by the increase of contribution of wood vegetation vs. herbaceous peat-forming plants, as well as by stability of water table during peatification.",
publisher = "Serbian Chemical Soc, Belgrade",
journal = "Journal of the Serbian Chemical Society",
title = "Characterisation of lignite lithotypes from the "Kovin" deposit (Serbia) - Implications from petrographic, biomarker and isotopic analysis",
volume = "82",
number = "6",
pages = "739-754",
doi = "10.2298/JSC161122030M"
}

Mitrović, D. D., Đoković, N., Životić, D. R., Bechtel, A., Cvetković, O.,& Stojanović, K. A.. (2017). Characterisation of lignite lithotypes from the "Kovin" deposit (Serbia) - Implications from petrographic, biomarker and isotopic analysis. in Journal of the Serbian Chemical Society
Serbian Chemical Soc, Belgrade., 82(6), 739-754.
https://doi.org/10.2298/JSC161122030M

Mitrović DD, Đoković N, Životić DR, Bechtel A, Cvetković O, Stojanović KA. Characterisation of lignite lithotypes from the "Kovin" deposit (Serbia) - Implications from petrographic, biomarker and isotopic analysis. in Journal of the Serbian Chemical Society. 2017;82(6):739-754.
doi:10.2298/JSC161122030M .

Mitrović, Danica D., Đoković, Nataša, Životić, Dragana R., Bechtel, Achim, Cvetković, Olga, Stojanović, Ksenija A., "Characterisation of lignite lithotypes from the "Kovin" deposit (Serbia) - Implications from petrographic, biomarker and isotopic analysis" in Journal of the Serbian Chemical Society, 82, no. 6 (2017):739-754,
https://doi.org/10.2298/JSC161122030M . .

TY  - JOUR
AU  - Mitrović, Danica D.
AU  - Đoković, Nataša
AU  - Životić, Dragana R.
AU  - Bechtel, Achim
AU  - Šajnović, Aleksandra
AU  - Stojanović, Ksenija A.
PY  - 2016
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/2372
AB  - The origin of the organic matter (OM) and the characteristics of the depositional environment of lignites from the Upper Miocene Kovin deposit (hosting three coal seams) of Serbia were evaluated based on petrographic data, bulk organic geochemical parameters, biomarker analysis and stable isotope geochemistry (delta C-13 of individual biomarkers). Samples were collected from four boreholes, GD-601 and GD-603 (the "A" field), and KB-79 and KB-91 (the "B" field), representing different parts of coal seams I, II, and III. Investigated lignites are typical humic coals. The OM of lignites is derived from woody vegetation and herbaceous peat-forming plants, with prevalence of the former in most samples. Peat-forming vegetation is characterized by abundant decay resistant gymnosperm (coniferous) plants, followed by a low amount of angiosperms. Lignite forming plants mostly belonged to the gymnosperm families Cupressaceae, Taxodiaceae, Phyllocladaceae and Pinaceae. Slight input of ferns, fungi and aquatic macrophyta to lignite OM is also evident. Distributions of hopanoids and isotopic compositions of these biomarkers reflect the activity of various microbial populations represented by methanotrophic-, chemoautotrophic- and heterotrophic bacteria during diagenesis. Prominent C-28 28,30-bisnorneohop-13(18)-ene was observed for the first time in the lignite extracts. According to the delta C-13 value it was probably derived from chemoautotrophic bacteria. C28 28,30-bisnorneohop-13(18)-ene could be one of the possible precursors of a series of orphan aromatic hopanoids bearing an ethyl group at C-21, via progressive aromatization. Peatification proceeded in a fresh water environment under variable redox conditions, from anoxic to slightly oxic. All three coal seams are heterogeneous. The lower parts of the coal seams represent a topogenous fresh water peat mire with open water areas, which was subjected to inundations. The upper parts of coal seams represent a wet forest swamp with relatively stable conditions. Despite the observed variations in all three coal seams, the mean values of petrographic and organic geochemical parameters suggest general increasing of wetness and establishment of more stable conditions from seam III to seam I. Maceral and biomarker data indicate that rapid flooding of the bogs stopped peat growth in all three coal seams. Relatively frequent variations in all three coal seams, followed by repetition of lignite characteristics depict well the pronounced seasonality e.g. short term cycles of the climate during Late Miocene in investigated area. (C) 2016 Elsevier B.V. All rights reserved.
PB  - Elsevier Science Bv, Amsterdam
T2  - International Journal of Coal Geology
T1  - Petrographical and organic geochemical study of the Kovin lignite deposit, Serbia
VL  - 168
SP  - 80
EP  - 107
DO  - 10.1016/j.coal.2016.07.008
ER  - 

@article{
author = "Mitrović, Danica D. and Đoković, Nataša and Životić, Dragana R. and Bechtel, Achim and Šajnović, Aleksandra and Stojanović, Ksenija A.",
year = "2016",
abstract = "The origin of the organic matter (OM) and the characteristics of the depositional environment of lignites from the Upper Miocene Kovin deposit (hosting three coal seams) of Serbia were evaluated based on petrographic data, bulk organic geochemical parameters, biomarker analysis and stable isotope geochemistry (delta C-13 of individual biomarkers). Samples were collected from four boreholes, GD-601 and GD-603 (the "A" field), and KB-79 and KB-91 (the "B" field), representing different parts of coal seams I, II, and III. Investigated lignites are typical humic coals. The OM of lignites is derived from woody vegetation and herbaceous peat-forming plants, with prevalence of the former in most samples. Peat-forming vegetation is characterized by abundant decay resistant gymnosperm (coniferous) plants, followed by a low amount of angiosperms. Lignite forming plants mostly belonged to the gymnosperm families Cupressaceae, Taxodiaceae, Phyllocladaceae and Pinaceae. Slight input of ferns, fungi and aquatic macrophyta to lignite OM is also evident. Distributions of hopanoids and isotopic compositions of these biomarkers reflect the activity of various microbial populations represented by methanotrophic-, chemoautotrophic- and heterotrophic bacteria during diagenesis. Prominent C-28 28,30-bisnorneohop-13(18)-ene was observed for the first time in the lignite extracts. According to the delta C-13 value it was probably derived from chemoautotrophic bacteria. C28 28,30-bisnorneohop-13(18)-ene could be one of the possible precursors of a series of orphan aromatic hopanoids bearing an ethyl group at C-21, via progressive aromatization. Peatification proceeded in a fresh water environment under variable redox conditions, from anoxic to slightly oxic. All three coal seams are heterogeneous. The lower parts of the coal seams represent a topogenous fresh water peat mire with open water areas, which was subjected to inundations. The upper parts of coal seams represent a wet forest swamp with relatively stable conditions. Despite the observed variations in all three coal seams, the mean values of petrographic and organic geochemical parameters suggest general increasing of wetness and establishment of more stable conditions from seam III to seam I. Maceral and biomarker data indicate that rapid flooding of the bogs stopped peat growth in all three coal seams. Relatively frequent variations in all three coal seams, followed by repetition of lignite characteristics depict well the pronounced seasonality e.g. short term cycles of the climate during Late Miocene in investigated area. (C) 2016 Elsevier B.V. All rights reserved.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "International Journal of Coal Geology",
title = "Petrographical and organic geochemical study of the Kovin lignite deposit, Serbia",
volume = "168",
pages = "80-107",
doi = "10.1016/j.coal.2016.07.008"
}

Mitrović, D. D., Đoković, N., Životić, D. R., Bechtel, A., Šajnović, A.,& Stojanović, K. A.. (2016). Petrographical and organic geochemical study of the Kovin lignite deposit, Serbia. in International Journal of Coal Geology
Elsevier Science Bv, Amsterdam., 168, 80-107.
https://doi.org/10.1016/j.coal.2016.07.008

Mitrović DD, Đoković N, Životić DR, Bechtel A, Šajnović A, Stojanović KA. Petrographical and organic geochemical study of the Kovin lignite deposit, Serbia. in International Journal of Coal Geology. 2016;168:80-107.
doi:10.1016/j.coal.2016.07.008 .

Mitrović, Danica D., Đoković, Nataša, Životić, Dragana R., Bechtel, Achim, Šajnović, Aleksandra, Stojanović, Ksenija A., "Petrographical and organic geochemical study of the Kovin lignite deposit, Serbia" in International Journal of Coal Geology, 168 (2016):80-107,
https://doi.org/10.1016/j.coal.2016.07.008 . .

TY  - JOUR
AU  - Životić, Dragana R.
AU  - Bechtel, Achim
AU  - Sachsenhofer, Rainhard
AU  - Gratzer, Rainhard
AU  - Radic, Dejan
AU  - Obradović, Marko
AU  - Stojanović, Ksenija A.
PY  - 2015
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/1710
AB  - The influence of different coal lithotypes on grindability has been investigated using lignite from two of the most important Upper Miocene lignite basins in Serbia (Kolubara and Kostolac). Yellow xylite-rich types demonstrated the most negative impact on Hardgrove Grindability Index (HGI). All different types of xylite-rich coal, as well as total xylite-rich coal from the Kolubara basin have a negative influence on the grindability properties, while only the yellow type of xylite-rich coal from the Kostolac showed a negative impact on HGI. Matrix coal does not show a clear effect on HGI. A negative correlation between textinite content and HGI is observed in both basins, whereas contents of other macerals do not show influence on grindability properties. Content of total organic carbon demonstrated the negative impact on HGI. Correlation analysis indicates that the negative impact of the yellow type of xylite-rich coal and the sum of total xylite-rich coal on the grindability properties partly can be related to content of total organic carbon and high amount of soluble organic matter. Matrix lithotype does not show any significant correlation with bulk geochemical parameters in both basins. The peat-forming vegetation of all samples from both basins were dominated by decay-resistant gymnosperm (coniferous) plants, belonging to one or several of the families Taxodiaceae, Podocarpaceae, Cupressaceae, Araucariaceae, Phyllocladaceae and Pinaceae. Lignite from the Kolubara basin is characterized by a higher contribution of angiosperm vegetation than coal from the Kostolac basin. Peatification of the Kolubara coal occurred under more oxic conditions than the Kostolac one. Analysis of biomarkers indicated that the negative impact of all types of xylite-rich coal from the Kolubara on HGI can be related to the higher proportion of angiosperms, abundance of mid-chain n-alkanes and sesquiterpenoids, aromatization of non-hopanoid triterpenoids and hopanoids, and intense degradation of wood tissues in a more oxic environment. The positive impact of matrix coal on HGI in the Kolubara samples can be attributed to elevated content of non-aromatic hopanoids and low amounts of aromatic non-hopanoid triterpenoids and sesquiterpenoids, which seems to hinder the grindability properties.
PB  - Elsevier Science Bv, Amsterdam
T2  - International Journal of Coal Geology
T1  - Petrological and organic geochemical properties of lignite from the Kolubara and Kostolac basins, Serbia: Implication on Grindability Index (Reprinted)
VL  - 139
SP  - 165
EP  - 183
DO  - 10.1016/j.coal.2014.10.006
ER  - 

@article{
author = "Životić, Dragana R. and Bechtel, Achim and Sachsenhofer, Rainhard and Gratzer, Rainhard and Radic, Dejan and Obradović, Marko and Stojanović, Ksenija A.",
year = "2015",
abstract = "The influence of different coal lithotypes on grindability has been investigated using lignite from two of the most important Upper Miocene lignite basins in Serbia (Kolubara and Kostolac). Yellow xylite-rich types demonstrated the most negative impact on Hardgrove Grindability Index (HGI). All different types of xylite-rich coal, as well as total xylite-rich coal from the Kolubara basin have a negative influence on the grindability properties, while only the yellow type of xylite-rich coal from the Kostolac showed a negative impact on HGI. Matrix coal does not show a clear effect on HGI. A negative correlation between textinite content and HGI is observed in both basins, whereas contents of other macerals do not show influence on grindability properties. Content of total organic carbon demonstrated the negative impact on HGI. Correlation analysis indicates that the negative impact of the yellow type of xylite-rich coal and the sum of total xylite-rich coal on the grindability properties partly can be related to content of total organic carbon and high amount of soluble organic matter. Matrix lithotype does not show any significant correlation with bulk geochemical parameters in both basins. The peat-forming vegetation of all samples from both basins were dominated by decay-resistant gymnosperm (coniferous) plants, belonging to one or several of the families Taxodiaceae, Podocarpaceae, Cupressaceae, Araucariaceae, Phyllocladaceae and Pinaceae. Lignite from the Kolubara basin is characterized by a higher contribution of angiosperm vegetation than coal from the Kostolac basin. Peatification of the Kolubara coal occurred under more oxic conditions than the Kostolac one. Analysis of biomarkers indicated that the negative impact of all types of xylite-rich coal from the Kolubara on HGI can be related to the higher proportion of angiosperms, abundance of mid-chain n-alkanes and sesquiterpenoids, aromatization of non-hopanoid triterpenoids and hopanoids, and intense degradation of wood tissues in a more oxic environment. The positive impact of matrix coal on HGI in the Kolubara samples can be attributed to elevated content of non-aromatic hopanoids and low amounts of aromatic non-hopanoid triterpenoids and sesquiterpenoids, which seems to hinder the grindability properties.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "International Journal of Coal Geology",
title = "Petrological and organic geochemical properties of lignite from the Kolubara and Kostolac basins, Serbia: Implication on Grindability Index (Reprinted)",
volume = "139",
pages = "165-183",
doi = "10.1016/j.coal.2014.10.006"
}

Životić, D. R., Bechtel, A., Sachsenhofer, R., Gratzer, R., Radic, D., Obradović, M.,& Stojanović, K. A.. (2015). Petrological and organic geochemical properties of lignite from the Kolubara and Kostolac basins, Serbia: Implication on Grindability Index (Reprinted). in International Journal of Coal Geology
Elsevier Science Bv, Amsterdam., 139, 165-183.
https://doi.org/10.1016/j.coal.2014.10.006

Životić DR, Bechtel A, Sachsenhofer R, Gratzer R, Radic D, Obradović M, Stojanović KA. Petrological and organic geochemical properties of lignite from the Kolubara and Kostolac basins, Serbia: Implication on Grindability Index (Reprinted). in International Journal of Coal Geology. 2015;139:165-183.
doi:10.1016/j.coal.2014.10.006 .

Životić, Dragana R., Bechtel, Achim, Sachsenhofer, Rainhard, Gratzer, Rainhard, Radic, Dejan, Obradović, Marko, Stojanović, Ksenija A., "Petrological and organic geochemical properties of lignite from the Kolubara and Kostolac basins, Serbia: Implication on Grindability Index (Reprinted)" in International Journal of Coal Geology, 139 (2015):165-183,
https://doi.org/10.1016/j.coal.2014.10.006 . .

TY  - CONF
AU  - Mitrović, Danica D.
AU  - Đoković, Nataša
AU  - Životić, Dragana R.
AU  - Bechtel, Achim
AU  - Stojanović, Ksenija A.
PY  - 2015
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/2817
PB  - Schriftenreihe der Deutschen Gesellschaft für Geowissenschaften (SDGG)
C3  - 67th Annual Meeting of the International Committee for Coal and Organic Petrology
T1  - Palaeoenvironmental reconstruction of the Kovin lignite deposit, Serbia
UR  - https://hdl.handle.net/21.15107/rcub_cherry_2817
ER  - 

@conference{
author = "Mitrović, Danica D. and Đoković, Nataša and Životić, Dragana R. and Bechtel, Achim and Stojanović, Ksenija A.",
year = "2015",
publisher = "Schriftenreihe der Deutschen Gesellschaft für Geowissenschaften (SDGG)",
journal = "67th Annual Meeting of the International Committee for Coal and Organic Petrology",
title = "Palaeoenvironmental reconstruction of the Kovin lignite deposit, Serbia",
url = "https://hdl.handle.net/21.15107/rcub_cherry_2817"
}

Mitrović, D. D., Đoković, N., Životić, D. R., Bechtel, A.,& Stojanović, K. A.. (2015). Palaeoenvironmental reconstruction of the Kovin lignite deposit, Serbia. in 67th Annual Meeting of the International Committee for Coal and Organic Petrology
Schriftenreihe der Deutschen Gesellschaft für Geowissenschaften (SDGG)..
https://hdl.handle.net/21.15107/rcub_cherry_2817

Mitrović DD, Đoković N, Životić DR, Bechtel A, Stojanović KA. Palaeoenvironmental reconstruction of the Kovin lignite deposit, Serbia. in 67th Annual Meeting of the International Committee for Coal and Organic Petrology. 2015;.
https://hdl.handle.net/21.15107/rcub_cherry_2817 .

Mitrović, Danica D., Đoković, Nataša, Životić, Dragana R., Bechtel, Achim, Stojanović, Ksenija A., "Palaeoenvironmental reconstruction of the Kovin lignite deposit, Serbia" in 67th Annual Meeting of the International Committee for Coal and Organic Petrology (2015),
https://hdl.handle.net/21.15107/rcub_cherry_2817 .

TY  - JOUR
AU  - Životić, Dragana R.
AU  - Bechtel, Achim
AU  - Sachsenhofer, Rainhard
AU  - Gratzer, Rainhard
AU  - Radic, Dejan
AU  - Obradović, Marko
AU  - Stojanović, Ksenija A.
PY  - 2014
UR  - https://cherry.chem.bg.ac.rs/handle/123456789/1867
AB  - The influence of different coal lithotypes on grindability has been investigated using lignite from two of the most important Upper Miocene lignite basins in Serbia (Kolubara and Kostolac). Yellow xylite-rich types demonstrated the most negative impact on Hardgrove Grindability Index (HGI). All different types of xylite-rich coal, as well as total xylite-rich coal from the Kolubara basin have a negative influence on the grindability properties, while only the yellow type of xylite-rich coal from the Kostolac showed a negative impact on HGI. Matrix coal does not show a clear effect on HGI. A negative correlation between textinite content and HGI is observed in both basins, whereas contents of other macerals do not show influence on grindability properties. Content of total organic carbon demonstrated the negative impact on HGI. Correlation analysis indicates that the negative impact of the yellow type of xylite-rich coal and the sum of total xylite-rich coal on the grindability properties partly can be related to content of total organic carbon and high amount of soluble organic matter. Matrix lithotype does not show any significant correlation with bulk geochemical parameters in both basins. The peat-forming vegetation of all samples from both basins were dominated by decay-resistant gymnosperm (coniferous) plants, belonging to one or several of the families Taxodiaceae, Podocarpaceae, Cupressaceae, Araucariaceae, Phyllocladaceae and Pinaceae. Lignite from the Kolubara basin is characterized by a higher contribution of angiosperm vegetation than coal from the Kostolac basin. Peatification of the Kolubara coal occurred under more oxic conditions than the Kostolac one. Analysis of biomarkers indicated that the negative impact of all types of xylite-rich coal from the Kolubara on HGI can be related to the higher proportion of angiosperms, abundance of mid-chain n-alkanes and sesquiterpenoids, aromatization of non-hopanoid triterpenoids and hopanoids, and intense degradation of wood tissues in a more oxic environment. The positive impact of matrix coal on HGI in the Kolubara samples can be attributed to elevated content of non-aromatic hopanoids and low amounts of aromatic non-hopanoid triterpenoids and sesquiterpenoids, which seems to hinder the grindability properties. (C) 2014 Elsevier B.V. All rights reserved.
PB  - Elsevier Science Bv, Amsterdam
T2  - International Journal of Coal Geology
T1  - Petrological and organic geochemical properties of lignite from the Kolubara and Kostolac basins, Serbia: Implication on Grindability Index
VL  - 131
SP  - 344
EP  - 362
DO  - 10.1016/j.coal.2014.07.004
ER  - 

@article{
author = "Životić, Dragana R. and Bechtel, Achim and Sachsenhofer, Rainhard and Gratzer, Rainhard and Radic, Dejan and Obradović, Marko and Stojanović, Ksenija A.",
year = "2014",
abstract = "The influence of different coal lithotypes on grindability has been investigated using lignite from two of the most important Upper Miocene lignite basins in Serbia (Kolubara and Kostolac). Yellow xylite-rich types demonstrated the most negative impact on Hardgrove Grindability Index (HGI). All different types of xylite-rich coal, as well as total xylite-rich coal from the Kolubara basin have a negative influence on the grindability properties, while only the yellow type of xylite-rich coal from the Kostolac showed a negative impact on HGI. Matrix coal does not show a clear effect on HGI. A negative correlation between textinite content and HGI is observed in both basins, whereas contents of other macerals do not show influence on grindability properties. Content of total organic carbon demonstrated the negative impact on HGI. Correlation analysis indicates that the negative impact of the yellow type of xylite-rich coal and the sum of total xylite-rich coal on the grindability properties partly can be related to content of total organic carbon and high amount of soluble organic matter. Matrix lithotype does not show any significant correlation with bulk geochemical parameters in both basins. The peat-forming vegetation of all samples from both basins were dominated by decay-resistant gymnosperm (coniferous) plants, belonging to one or several of the families Taxodiaceae, Podocarpaceae, Cupressaceae, Araucariaceae, Phyllocladaceae and Pinaceae. Lignite from the Kolubara basin is characterized by a higher contribution of angiosperm vegetation than coal from the Kostolac basin. Peatification of the Kolubara coal occurred under more oxic conditions than the Kostolac one. Analysis of biomarkers indicated that the negative impact of all types of xylite-rich coal from the Kolubara on HGI can be related to the higher proportion of angiosperms, abundance of mid-chain n-alkanes and sesquiterpenoids, aromatization of non-hopanoid triterpenoids and hopanoids, and intense degradation of wood tissues in a more oxic environment. The positive impact of matrix coal on HGI in the Kolubara samples can be attributed to elevated content of non-aromatic hopanoids and low amounts of aromatic non-hopanoid triterpenoids and sesquiterpenoids, which seems to hinder the grindability properties. (C) 2014 Elsevier B.V. All rights reserved.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "International Journal of Coal Geology",
title = "Petrological and organic geochemical properties of lignite from the Kolubara and Kostolac basins, Serbia: Implication on Grindability Index",
volume = "131",
pages = "344-362",
doi = "10.1016/j.coal.2014.07.004"
}

Životić, D. R., Bechtel, A., Sachsenhofer, R., Gratzer, R., Radic, D., Obradović, M.,& Stojanović, K. A.. (2014). Petrological and organic geochemical properties of lignite from the Kolubara and Kostolac basins, Serbia: Implication on Grindability Index. in International Journal of Coal Geology
Elsevier Science Bv, Amsterdam., 131, 344-362.
https://doi.org/10.1016/j.coal.2014.07.004

Životić DR, Bechtel A, Sachsenhofer R, Gratzer R, Radic D, Obradović M, Stojanović KA. Petrological and organic geochemical properties of lignite from the Kolubara and Kostolac basins, Serbia: Implication on Grindability Index. in International Journal of Coal Geology. 2014;131:344-362.
doi:10.1016/j.coal.2014.07.004 .

Životić, Dragana R., Bechtel, Achim, Sachsenhofer, Rainhard, Gratzer, Rainhard, Radic, Dejan, Obradović, Marko, Stojanović, Ksenija A., "Petrological and organic geochemical properties of lignite from the Kolubara and Kostolac basins, Serbia: Implication on Grindability Index" in International Journal of Coal Geology, 131 (2014):344-362,
https://doi.org/10.1016/j.coal.2014.07.004 . .