Variations in δ13C values of levoglucosan from low-temperature burning of lignite and biomass

Levoglucosan, an anhydrosaccharide, is commonly used as an organic tracer for biomass burning, but has also been identified from coal smoke particulate matter (PM) including lignites. Here we showed that stable carbon isotope analysis specifically of levoglucosan may be one possible way to determine the relative contributions from coal combustion versus biomass burning sources. PM sampleswere collected from low-temperature burning/ smoldering of Miocene lignites from Poland and basket willow (Salix viminalis L.) representative of biomass. The calculated levoglucosan δ13C values of xylites varied from −23.6 to−21.6‰, while for detritic coal samples they ranged from −24.2 to −23.1‰, with means of −22.7 and −23.7‰, respectively. The calculated levoglucosan δ13C value of basketwillow woodwas−27.1‰. Values ofwillowwoodmixtureswith xylite varied from−25.8 to−23.4‰(with an increasing proportion of xylite), while values of mixtures of willow and detritic coal ranged from−26.9 to−24.6‰(with an increasing proportion of detritic coal). The δ13C values for themixtures changed proportionally to the contents of individual components with R2=0.88 and 0.89 for willow with xylite and detritic coal, respectively. The hopanoid distributions characteristic for low-temperature lignite/peat burning, with a predominance of 22R-α,β-homohopane, ββ-hopanes and hopenes, as well as low or very low values of the homohopane index,were observed in smokePMfrommost lignite samples and absent in the basket willow sample. Thus, the relatively high content of hopanes (with the occurrence of 22R-α,β-homohopane, ββ- hopanes and hopenes) in atmospheric PM samples can be treated as additional tracers of lignite combustion

Interactions between microbial degradation of sedimentary organic matter and lake hydrodynamics in shallow water bodies: insights from Lake Sarbsko (northern Poland)

In this paper we demonstrate spatial and seasonal changes in the pathways of microbial decomposition of organic matter within the surface sediments of Lake Sarbsko, a coastal water body located on the middle Polish-Baltic coast. We studied lake waters and bottom sediments at 11 sampling stations throughout the basin and in different seasons between November 2007 and September 2008. It was established that, in this very productive and shallow lake, microbial activity increases in warmer seasons and ceases during winter. In spring, bacterial activity is fuelled by increased influx of highly reactive planktonic organic matter, which is decomposed via methanogenesis, reduction of NO3 -, SO4 2-, and Fe and Mn oxides. On the other hand, during summer, oxidation processes (mainly oxidation of CH4) tend to predominate. The change from reduction to oxidation is attributed to wind-induced vertical mixing of Lake Sarbsko waters and resuspension of bottom deposits. Degradation of sedimentary organic matter in Lake Sarbsko results in appreciable changes in the pH and the concentrations of red-ox sensitive ions in pore waters, but it has little effect on the chemistry of bottom and surface waters. However, release of PO4 3- from the sediments might be a source of this nutrient in the lake. Internal loading of phosphates in Lake Sarbsko occurs under both oxic/mildly reducing and anoxic conditions

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

Supplementray material for: [https://doi.org/10.2298/JSC171215027K]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2201

Reconstruction of peat-forming paleoenvironments within the Oligocene Bobov Dol Basin, SW Bulgaria: Insights from organic petrology

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 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)

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

Comprehensive Study of Liptinite-Rich Coal from the Pliocene Jinsuo Basin and the Eocene Shenbei Basin (China)

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

Paleoenvironmental settings of peat formation within Padesh Graben, SW Bulgaria, deduced from maceral analysis and geochemical properties of Suhostrel Coal

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

Comparative Petrographical and Organic Geochemical Study of Eocene and Oligocene Coal Basins from Sw Bulgaria

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

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