Origin and paleoenvironmental reconstruction of the "Kovin" coal deposit - implications from petrographic and geochemical investigations.

Ispitivani su uzorci lignita, starosti gornjeg miocena (pont), iz ležišta „Kovin“ u cilju utvrđivanja porekla organske supstance (OS) i određivanja karakteristika depozicione sredine. Korišćene su petrografska analiza, grupni organsko-geohemijski parametri, biomarkerska analiza i merenje izotopskog sastava ugljenika (δ13C) pojedinačnih biomarkerskih jedinjenja u zasićenoj i aromatičnoj frakciji uglja...Lignite samples from Upper Miocene (Pontian) „Kovin“ deposit were investigated in order to asses the origin of organic matter (OM) and evaluate characteristics of depositional environment. Petrographic analysis, bulk organic geochemical parameters, biomarker analysis and carbon isotopic composition (δ13C) of individual biomarker compounds in saturated and aromatic fraction of coal were used..

Origin and paleoenvironmental reconstruction of the "Kovin" coal deposit - implications from petrographic and geochemical investigations.

Ispitivani su uzorci lignita, starosti gornjeg miocena (pont), iz ležišta „Kovin“ u cilju utvrđivanja porekla organske supstance (OS) i određivanja karakteristika depozicione sredine. Korišćene su petrografska analiza, grupni organsko-geohemijski parametri, biomarkerska analiza i merenje izotopskog sastava ugljenika (δ13C) pojedinačnih biomarkerskih jedinjenja u zasićenoj i aromatičnoj frakciji uglja...Lignite samples from Upper Miocene (Pontian) „Kovin“ deposit were investigated in order to asses the origin of organic matter (OM) and evaluate characteristics of depositional environment. Petrographic analysis, bulk organic geochemical parameters, biomarker analysis and carbon isotopic composition (δ13C) of individual biomarker compounds in saturated and aromatic fraction of coal were used..

Maceral and biomarker composition of lignite lithotypes - Implications on palaeoenvironment and grindability properties

Maceral and biomarker composition of different lignite lithotypes: matrix-coal, pale yellow xylite-rich coal, dark yellow xylite-rich coal, brown xylite-rich coal, mineral-rich coal and dopplerite originating from the Upper Miocene (“Pontian”) Kostolac Basin, Serbia was studied in detail. The objective was to establish the sources of organic matter and to determine palaeoenvironmental conditions which resulted in formation of different lignite lithotypes. Moreover, the influence of lignite lithotypes on grindability properties has also been assessed. Mineral-rich coal was formed in topogenous fresh water peat mire with open water areas. Formation of matrix coal was performed in reed march. The peatification of pale yellow- and dark yellow xylite proceeded in dry forest swamp. Brown xylite was formed in wet forest swamp, whereas dopplerite could have formed during transition of wet forest swamp into bush mire. Contents of liptinites, inertinites, gelinite, mineral matter, sesquiterpenoids, hopanoids and n-alkanes have positive impact on Hardgrove Grindability Index (HGI), whereas total huminites, telohuminite and total organic carbon content, as well as retene/2-methyl, 1-(4’-methylpentyl), 6-isopropylnaphthalene ratio exhibited negative influence on HGI

Petrographical and organic geochemical study of the lignite from the Smederevsko Pomoravlje field (Kostolac Basin, Serbia)

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

Characterisation of lignite lithotypes from the "Kovin" deposit (Serbia) - Implications from petrographic, biomarker and isotopic analysis

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

Petrographic and biomarker analysis of xylite-rich coal from the Kolubara and Kostolac lignite basins (Pannonian Basin, Serbia)

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

Preliminary organic geochemical study of lignite from the Smederevsko Pomoravlje field (Kostolac Basin, Serbia) - Reconstruction of geological evolution and potential for rational utilization

The study was aimed at determining the origin and geological evolution of lignites from the Smederevsko Pomoravlje field (Kostolac Basin, Serbia). The possibility of a rational utilization of the coal was also considered. For this purpose, numerous organic geochemical analyses were applied to representative lignite samples. The obtained results showed that the coal from the Smederevsko Pomoravlje field is a typical humic coal. The peat-forming vegetation was dominated by gymnosperm plants. The coal-forming plants belonged to the gymnosperm families Taxodiaceae, Cupressaceae, Phyllo-cladaceae and Pinaceae. Other precursors of organic matter (OM) were microbial biomass ferns and angiosperms. It was established that peatification occurred in a neutral to slightly acidic, fresh water environment Under anoxic to suboxic redox conditions. The maturity of the OM is low, in the phase of intense diagenetic processes. The biomarker compositions and values of the corresponding parameters revealed that the Smederevsko Pomoravlje field, the Drmno field (Kostolac Basin) and the "A" field (Kovin deposit) represent a part of a unique lignite basin. The results of this study suggest possible rational utilization of the Smederevsko Pomoravlje lignites in thermal power plants. This is particularly related to samples from coal seam I. A significant amount of gas could be generated from lignites at higher maturities. Eight samples met the basic assumptions for effective gasification

Origin and paleoenvironmental reconstruction of the "Kovin" coal deposit - implications from petrographic and geochemical investigations.

Ispitivani su uzorci lignita, starosti gornjeg miocena (pont), iz ležišta „Kovin“ u cilju utvrđivanja porekla organske supstance (OS) i određivanja karakteristika depozicione sredine. Korišćene su petrografska analiza, grupni organsko-geohemijski parametri, biomarkerska analiza i merenje izotopskog sastava ugljenika (δ13C) pojedinačnih biomarkerskih jedinjenja u zasićenoj i aromatičnoj frakciji uglja...Lignite samples from Upper Miocene (Pontian) „Kovin“ deposit were investigated in order to asses the origin of organic matter (OM) and evaluate characteristics of depositional environment. Petrographic analysis, bulk organic geochemical parameters, biomarker analysis and carbon isotopic composition (δ13C) of individual biomarker compounds in saturated and aromatic fraction of coal were used..

Origin and paleoenvironmental reconstruction of the "Kovin" coal deposit - implications from petrographic and geochemical investigations.

Ispitivani su uzorci lignita, starosti gornjeg miocena (pont), iz ležišta „Kovin“ u cilju utvrđivanja porekla organske supstance (OS) i određivanja karakteristika depozicione sredine. Korišćene su petrografska analiza, grupni organsko-geohemijski parametri, biomarkerska analiza i merenje izotopskog sastava ugljenika (δ13C) pojedinačnih biomarkerskih jedinjenja u zasićenoj i aromatičnoj frakciji uglja...Lignite samples from Upper Miocene (Pontian) „Kovin“ deposit were investigated in order to asses the origin of organic matter (OM) and evaluate characteristics of depositional environment. Petrographic analysis, bulk organic geochemical parameters, biomarker analysis and carbon isotopic composition (δ13C) of individual biomarker compounds in saturated and aromatic fraction of coal were used..