@article{2-s2.0-85168546328,

title = {Interlaboratory study: Testing reproducibility of solid biofuels component identification using reflected light microscopy},

author = { A. Drobniak and M. Mastalerz and Z. Jelonek and I. Jelonek and T. Adsul and N.M. Andolšek and O.H. Ardakani and T. Congo and B. Demberelsuren and B.S. Donohoe and A. Douds and D. Flores and R. Ganzorig and S. Ghosh and A.P. Giże and P.A. Gonçalves and P.C. Hackley and J.J. Hatcherian and J.C. Hower and S. Kalaitzidis and S. Kędzior and W.R. Knowles and J. Kus and K. Lis and G.P. Lis and Be. Liu and Q. Luo and M. Du and D.K. Mishra and M. Misz-Kennan and T. Mugerwa and J.L. Nedzweckas and J.M.K. O'Keefe and Ja. Park and R. Pearson and H.I. Petersen and J. Reyes and J. Ribeiro and G. de la Rosa-Rodríguez and P. Sosnowski and B.J. Valentine and A.K. Varma and M. Wojtaszek-Kalaitzidi and Zh. Xu and A. Zdravkov and K. Ziemianin},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85168546328&doi=10.1016%2fj.coal.2023.104331&partnerID=40&md5=437705b071d6453eaaf41d2816f52333},

doi = {10.1016/j.coal.2023.104331},

issn = {01665162},

year  = {2023},

date = {2023-01-01},

journal = {International Journal of Coal Geology},

volume = {277},

publisher = {Elsevier B.V.},

abstract = {Considering global market trends and concerns about climate change and sustainability, increased biomass use for energy is expected to continue. As more diverse materials are being utilized to manufacture solid biomass fuels, it is critical to implement quality assessment methods to analyze these fuels thoroughly. One such method is reflected light microscopy (RLM), which has the potential to complement and enhance current standard testing, leading to improving fuel quality assessment and, ultimately, preventing avoidable air pollution. An interlaboratory study (ILS) was conducted to test the reproducibility of biomass fuels component identification using a reflected light microscopy technique. The exercise was conducted on thirty photomicrographs showing biomass and various undesired components (like plastics or mineral matter), which were purposely added (by the ILS organizers) to contaminate wood pellets and charcoal-based grilling fuels. Forty-six participants had various levels of difficulty identifying the marked components, and as a result, the percentage of correct answers ranged from 52.2 to 94.4%. Among the most difficult components to distinguish were petroleum products and inorganic matter. Various reasons led to the misidentification, including insufficient morphological descriptions of the components provided to participants, ambiguities of the nomenclature, limitations of the analytical and exercise method, and insufficient experience of the participants. Overall, the results indicate that RLM has the potential to enhance the quality assessment of biomass fuels. However, they also demonstrate that the petrographic classification used in this exercise requires further refinement before it can be standardized. While a new simplified classification of solid biomass fuels components was created as an outcome of this study, future research is necessary to refine the nomenclature, develop a microscopic morphological description of the components, and verify the accuracy of component identification with a follow-up ILS. © 2023 Elsevier B.V.},

note = {2},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85152519464,

title = {Coal Properties and Coalbed Methane Potential in the Southern Part of the Upper Silesian Coal Basin, Poland},

author = { S. Kędzior and L. Teper},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85152519464&doi=10.3390%2fen16073219&partnerID=40&md5=42af6a078dc0c774bb3605408830a9c4},

doi = {10.3390/en16073219},

issn = {19961073},

year  = {2023},

date = {2023-01-01},

journal = {Energies},

volume = {16},

number = {7},

publisher = {MDPI},

abstract = {The area studied covers unmined Pennsylvanian Ćwiklice and Dankowice coal deposits located in the southern part of the Upper Silesian Coal Basin, Poland. The geological structure of the area clearly affects the current distribution of methane. The content of methane is lower in coal seams lying within porous and permeable sandstones (Łaziska sandstones), whereas it is higher in seams that occur in sequences (Mudstone Series) where impermeable shales and mudstones occur. Due to the previous attempts to extract methane from boreholes, this area, characterized by a dense network of exploratory and prospecting drillings, is worth analyzing with regard to the conditions of methane occurrence in terms of extraction possibilities. Using contour maps, cross-sections and profiles, the variability of methane content and resources, as well as the moisture and ash content of coal seams, were analyzed. Methane content isolines are parallel to the boundary between the Cracow Sandstone Series and the Mudstone Series and to main faults. Coal moisture contents clearly reduce methane contents. A high methane content >8 m3/t coaldaf is typical for coal seams in which moisture contents do not exceed 5%. High- and medium-volatile bituminous coal in the area is characterized by low methane saturation, though saturation increases with depth. Coal permeability is variable (from 0.2 to more than 100 mD), but, below a depth of 1200 m, a clear trend of decreasing permeability with depth is evident. From the point of view of coalbed methane (CBM) recovery, relatively low coal permeabilities and methane saturation levels could make CBM output problematic in the studied area. Methane production will be more probable as a result of demethanation of the Dankowice 1 deposit, where coal mining is planned. This will result in the emission of methane into the atmosphere from ventilation shafts and methane drainage stations. Therefore, effective use of the gas captured by the methane drainage station is highly desirable for environmental and economic reasons. © 2023 by the authors.},

note = {2},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85152531818,

title = {Time Variability of Methane Extraction from Hard Coal Deposits in the Upper Silesian Coal Basin (Poland) in Relation to Geological and Mining Conditions},

author = { S. Kędzior and M. Dreger},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85152531818&doi=10.46873%2f2300-3960.1379&partnerID=40&md5=c34ad43879394c1b5f0ac1947a32115d},

doi = {10.46873/2300-3960.1379},

issn = {25434950},

year  = {2023},

date = {2023-01-01},

journal = {Journal of Sustainable Mining},

volume = {22},

number = {2},

pages = {89-99},

publisher = {Głowny Instytut Gornictwa (Central Mining Institute)},

abstract = {The extraction and economical use of methane from coal mines in the Upper Silesian Coal Basin, Poland (USCB) have shown a variable tendency in recent decades, with numerous fluctuations from year to year. In 2021, approximately 286 million m3 of methane was collected from coal mines, which accounted for approximately 40% of the total emissions of this gas to mine workings. Due to the fact that the economical use of coal mine methane brings environmental, economic and work safety benefits, increasing its extraction is an urgent need. Trends in changes in the amount of mined methane in the entire USCB and in the deposits where the most methane was extracted in the last 25 years were analysed. The most important potential factors influencing the variability of coal mine gas extraction were taken into account, i.e. elements of the geological structure, coal extraction, methane emissions, mining and technical conditions, etc. The di-rections for using the collected methane and the main consumers were discussed. The aim is to indicate the most important problems faced by coal mining in terms of the capture and management of methane over the last 25 years and to outline possible solutions. © 2023, Głowny Instytut Gornictwa (Central Mining Institute). All rights reserved.},

note = {4},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85137982420,

title = {Geological and Mining Factors Controlling the Current Methane Conditions in the Rydułtowy Coal Mine (Upper Silesian Coal Basin, Poland)},

author = { S. Kędzior and M. Dreger},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85137982420&doi=10.3390%2fen15176364&partnerID=40&md5=b260597eb9918b805e20fa4ca0ab91c6},

doi = {10.3390/en15176364},

issn = {19961073},

year  = {2022},

date = {2022-01-01},

journal = {Energies},

volume = {15},

number = {17},

publisher = {MDPI},

abstract = {Methane emissions into mine workings and the atmosphere are still a significant environmental and work safety problem. Since 2000, the Rydułtowy coal mine, located in the western part of the Upper Silesian Coal Basin, has been struggling with significant methane emissions compared to the previous period. The distribution of the methane content in coal seams was analysed, and the factors that influenced it were reviewed. Then, the annual variability in methane emissions in mining excavations was investigated, and the depth of coal extraction was linked to methane conditions and the time of mining works. It has been shown that the currently observed distribution of methane in coal seams is the result of, inter alia, the geological development of the western part of the basin, the lithological character of coal-bearing Carboniferous deposits and overburden, and fault tectonics. The sorption capacity of coal seams decreases with increasing temperature and the coal rank. The amount of methane emitted into mine workings depends mainly on the methane content in the coal seams in mining sites and on the sorption capacity of the coal seams. The depth of exploitation, increasing from year to year, leads to an increase in the methane content in coal seams and a simultaneous decrease in the sorption capacity of coal, which will result in higher methane emissions in the future. © 2022 by the authors.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85118437135,

title = {Methane emissions against the background of natural and mining conditions in the Budryk and Pniówek mines in the Upper Silesian Coal Basin (Poland)},

author = { M. Dreger and S. Kędzior},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85118437135&doi=10.1007%2fs12665-021-10063-4&partnerID=40&md5=9d722db89feef800009c689cfbc60206},

doi = {10.1007/s12665-021-10063-4},

issn = {18666280},

year  = {2021},

date = {2021-01-01},

journal = {Environmental Earth Sciences},

volume = {80},

number = {22},

publisher = {Springer Science and Business Media Deutschland GmbH},

abstract = {The paper presents the variability of hard coal output, methane content and methane emissions into coal workings and into the atmosphere from the two most methane-gassy coal mines in Poland. The Budryk mine is one of the youngest mines in Poland, but it is the most methane-gassy as well. In 2016, the total CH4 emissions exceed 140 million of m3. This large increase in methane emissions to mine workings is primarily related to the increase in the depth of coal extraction (up to 1290 m) and, consequently, the rapid increase in the methane content in coal seams (up to 10–12 m3/Mg coaldaf). On the other hand, in the Pniówek mine, methane emission was the highest at the beginning of the study period (1986–1991). During the following years, emission decreased to the values of less than 140 million of m3, which were still one of the largest amounts of emitted methane in the entire Upper Silesian Coal Basin. The coexistence of natural factors, such as the geological structure and gas distribution, as well as mining-related factors, i.e. the depth of mining, the intensity of coal extraction determines the temporal variability of methane emissions in the studied mines. © 2021, The Author(s).},

note = {3},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85086564715,

title = {Fluctuations in methane and carbon dioxide concentrations in the near-surface zone and their genetic characterization in abandoned and active coal mines in the SW part of the Upper Silesian Coal Basin, Poland},

author = { H. Sechman and M.J. Kotarba and S. Kędzior and A. Kochman and A. Twaróg},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85086564715&doi=10.1016%2fj.coal.2020.103529&partnerID=40&md5=24c75e4c36f81459bd50278d465d0157},

doi = {10.1016/j.coal.2020.103529},

issn = {01665162},

year  = {2020},

date = {2020-01-01},

journal = {International Journal of Coal Geology},

volume = {227},

publisher = {Elsevier B.V.},

abstract = {The objective of this paper is to determine the origin and variability of methane and carbon dioxide concentrations in the near-surface zone and of coalbed methane in the SW part of the Chwałowice Trough and adjacent areas of the Main Syncline of the Upper Silesian Coal Basin (USCB). For this purpose soil-gas samples were taken at 202 measuring points, arranged along 5 profiles located in the mining area of the abandoned 1 Maja mine and directly adjacent areas as well as in the vicinity of four abandoned and remediated mining shafts. The maximum methane and carbon dioxide concentrations in the gas samples measured exceeds 22 and 9 vol%, respectively. The carbon isotope composition of methane and carbon dioxide was determined in samples in which elevated concentrations of these gases were found. Moreover, seven coalbed gas samples and bituminous coals were collected from coal seams exclusively from virgin parts of the Anna, Marcel, Jastrzębie, and Zofiówka mines. These data were supplemented with results of archival research for genetic interpretation of coalbed gases. Research reveals that typical humic low- and medium-volatile bituminous coals occur in Mississippian and Pennsylvanian coal-bearing strata in the study area. Fluctuations in methane and carbon dioxide concentration in the near-surface zone are related to the lithostratigraphy and tectonics of the area as well as to complicated methane depth distribution. Faults may play an important role in the microseepage of gases from deep to the near-surface zone. The connection of near-surface gases with subsurface gases was confirmed by similar stable carbon isotope composition in the methane recorded in the soil-gas samples and in the gas samples from the coal seams and sandstones of the Carboniferous formations. Distribution of anomalous methane concentrations recorded in soil-gas samples taken from profiles may indicate natural gas accumulations in the top zone of the Pennsylvanian coal-bearing formations. One example of this kind of accumulation is the Marklowice natural gas field, located within the mining area of the Marcel coal mine. Relatively high methane concentrations measured in soil gas in the vicinity of shafts I and III indicate that the degassing systems of closed and remediated mining shafts are not fully effective. Increases in carbon dioxide concentrations in the surface zone and frequent associated decreases in methane concentration were most often the result of microbial methane oxidation. © 2020 The Authors},

note = {11},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85076632032,

title = {Distribution of methane and carbon dioxide concentrations in the near-surface zone over regional fault zones and their genetic characterization in the Pszczyna-Oświęcim area (SE part of the Upper Silesian Coal Basin, Poland)},

author = { H. Sechman and M.J. Kotarba and S. Kędzior and M. Dzieniewicz and T. Romanowski and A. Góra},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85076632032&doi=10.1016%2fj.petrol.2019.106804&partnerID=40&md5=453734595935641f098aefa8cc836bf9},

doi = {10.1016/j.petrol.2019.106804},

issn = {09204105},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Petroleum Science and Engineering},

volume = {187},

publisher = {Elsevier B.V.},

abstract = {The objective of this paper was to characterize the variability of methane (CH4) and carbon dioxide (CO2) concentrations in the near-surface zone, measured along 4 selected sampling lines positioned perpendicularly to regional fault zones, in the SE part of the Upper Silesian Coal Basin (USCB), Poland. This way it was possible to check the migration activity of these gases to the surface through low-permeable Miocene strata. It was also possible to evaluate the applicability of surface geochemical survey methodology to the identification of potential accumulations of free natural gas in the topmost parts of the Carboniferous formations in the USCB. The results of 319 soil-gas samples were supported by stable isotope analyses and related to the geological setting and the distribution of methane potential at various depths. Moreover, the sampling included the area of the closed and remediated Andrzej VII mining shaft, where 5 soil-gas samples were taken. Additionally, gas flux was evaluated at 3 measurement points at which increased gas concentrations were detected. The maximum concentrations of CH4 and CO2 in soil gases were 15.4 and 9.39 vol%, respectively. Soil gases contain both thermogenic and microbial CH4 and CO2 that migrated from secondary and primary gas zones within the Pennsylvanian coal-bearing strata. In some sites, CO2 was also generated by the oxidation of soil organic matter and/or CH4 in a near-surface zone. Anomalous CH4 concentrations were generally found over elevated fragments of erosional structures of Carboniferous coal-bearing formations. This indicates the presence of free CH4 accumulations beneath the Miocene overburden. However, the surface anomalies did not always correlate with the zones of CH4 secondary accumulations. Anomalous concentrations of CH4 and CO2 correlated with the regional fault zones that cut through the Carboniferous formations. This indicates the potential presence of fault traps saturated with free CH4 in the upper parts of Carboniferous formations. Relatively low values were observed for both CH4 and CO2 emissions (maximum: 25 and 4320 mg m−2 d−1; respectively). This suggests relatively low dynamics of gas migration from the depth to the soil zone. © 2019 Elsevier B.V.},

note = {6},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85067467879,

title = {Methane occurrence, emissions and hazards in the Upper Silesian Coal Basin, Poland},

author = { S. Kędzior and M. Dreger},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85067467879&doi=10.1016%2fj.coal.2019.103226&partnerID=40&md5=46894dd752ac36bcd12b27036b4d4986},

doi = {10.1016/j.coal.2019.103226},

issn = {01665162},

year  = {2019},

date = {2019-01-01},

journal = {International Journal of Coal Geology},

volume = {211},

publisher = {Elsevier B.V.},

abstract = {The paper presents the variability of methane emissions into mining excavations and the atmosphere in the Upper Silesian Coal Basin (USCB) (Poland) against the background of natural and mining factors. Emissions of methane from exploited coal seams have become a serious problem in the USCB due to the growing methane hazard in coal mines and emissions of methane into the atmosphere. In the mid-nineties 753 million m3 of methane was emitted annually from the USCB mines. Despite a significant drop in coal production over the next 20 years, methane emissions have not decreased sharply; on the contrary, in recent years they have begun to grow, and, in 2016, reached the level of 933 million m3 per year. This represents an increase of 180 million m3 per year since the mid-nineties. One of the important reasons for this phenomenon is the constantly increasing depth of coal exploitation, which in many mines now exceeds 1000 m; this is the depth corresponding to the deep methane zone, where the volume of accumulated methane in the coal seams is particularly high. Factors influencing the volume of methane emissions in relation to mine workings can be divided roughly into two groups: natural (geological) and anthropogenic (mining-related). Natural factors include methane content in coal seams, gas pressure, the presence of free gas in fault zones, related fissures and porous sandstone, the migration of methane through faults and fissures, and the presence of a continuous and impermeable Miocene overburden. Mining factors include the depth of exploitation and the concentration of coal production as expressed in terms of the length, height, and advance of walls. The interdependence of these factors means that, despite the decline in coal production, methane emissions, both total and specific, are increasing. This problem cannot be neglected, especially since it may grow worse in future. One measure to prevent the growth of methane emissions and the associated hazard may be the intensification of mine methane drainage and the economic use of captured mining gas, which is already done in the USCB. © 2019 Elsevier B.V.},

note = {31},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85063219716,

title = {Methane emissions and demethanation of coal mines in the Upper Silesian Coal Basin between 1997 and 2016},

author = { M. Dreger and S. Kędzior},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063219716&doi=10.2478%2fenviron-2019-0002&partnerID=40&md5=e3e78155da38d0dcc19163b816c7fc01},

doi = {10.2478/environ-2019-0002},

issn = {23540079},

year  = {2019},

date = {2019-01-01},

journal = {Environmental and Socio-Economic Studies},

volume = {7},

number = {1},

pages = {12-23},

publisher = {De Gruyter Open Ltd},

abstract = {Between 1997 and 2016 we observed important changes in hard coal extraction and methane emission in the Upper Silesian Coal Basin. Hard coal extraction in the near future will be very dangerous because it will be necessary to reach deeper methane-rich coal seams. Permanent monitoring of the volume of emitted and captured methane is necessary to combat the methane hazard. The predictability of gaseous hazards are important in order to keep underground work safe. We gathered and analysed data from three coal companies: Katowice Coal Holding, the Coal Company, Jastrzȩbie Coal Company and in the whole of the Upper Silesian Coal Basin for the last twenty years and this allowed us to notice changes and CH 4 trends in ventilation emission and demethanation. There is a decrease in the extraction of hard coal from year to year. At the same time there is an increase in the total methane emissions which forces actions aimed to effective contracting the methane hazard. Specifically, methane emission has been increasing for years, making hard coal extraction very dangerous. We observed increases in CH 4 vent emission and volume of methane coming from underground drainage systems. Much more methane is released during hard coal extraction at deeper mine levels. Throughout the entire research period the methane hazard increased. Therefore, the development of modern technologies for methane capturing should contribute to improvement of hazardous conditions for coal mining in the basin. © 2019 Marcin Dreger et al., published by Sciendo.},

note = {7},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85061406043,

title = {Distribution of methane and carbon dioxide concentrations in the near-surface zone, genetic implications, and evaluation of gas flux around abandoned shafts in the Jastrzębie-Pszczyna area (southern part of the Upper Silesian Coal Basin, Poland)},

author = { H. Sechman and M.J. Kotarba and S. Kędzior and M. Dzieniewicz and T. Romanowski and A. Twaróg},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85061406043&doi=10.1016%2fj.coal.2019.02.001&partnerID=40&md5=ddbe65c83c10fab12ed4b6382bce1bc6},

doi = {10.1016/j.coal.2019.02.001},

issn = {01665162},

year  = {2019},

date = {2019-01-01},

journal = {International Journal of Coal Geology},

volume = {204},

pages = {51-69},

publisher = {Elsevier B.V.},

abstract = {The objective of this paper is to evaluate the possible migration of coal-bed methane and carbon dioxide to the earth's surface in a selected areas from the southern part of the Upper Silesian Coal Basin (USCB) and resulted hazards produced by near-surface gas migration, referred to the geological setting and the origin of these gases. The surface geochemical survey was run over the areas of both the operating and the abandoned bituminous coal mines, including the remediated shafts and the regional tectonic dislocations: the Bzie-Czechowice and the Jawiszowice fault zones. The survey included a total of 453 soil gas samples collected at a depth of about 1.2 m and along 7 horizontal profiles as well as in the vicinities of remediated shafts. All collected gas samples were chromatographically analysed for methane and carbon dioxide concentrations. Selected samples showing increased concentrations of methane and/or carbon dioxide were analysed also for stable carbon isotopes of these gases. Additionally, gas emission was measured at 5 sites selected due to the increased concentrations of the gases. The maximum detected concentrations of methane and carbon dioxide in soil gas samples were 52.8 and 17.4 vol%, respectively. The closure of high methane-emitting bituminous coal mines in the USCB, including the termination of mine ventilation, caused the increase of average methane concentrations in the near-surface zone. Vast anomalies of both gases can be the effects of migration from secondary accumulations of “free” methane present in the elevated parts of Carboniferous formation capped by Miocene claystones and mudstones. Methane originated from primary accumulations located beneath the degassing zone and migrated along fault zones. However, carbon dioxide migrated from both the primary and the secondary accumulations, and, sometimes, it originated also from secondary oxidation of methane. The methane recovery captured with degassing wells run in the area of the abandoned “Morcinek” Mine disturbed the naturaly, vertically migrating methane towards the earth's surface and caused the local decrease of average methane concentrations in soil gas collected along the D-D' sampling line. It was additionally confirmed by relatively high methane concentrations (over 50 vol%) detected in samples collected from the wells degassing the shafts I, II and III of the closed “Morcinek” Mine. The methane is of microbial origin and migrated from secondary accumulation located within the Carboniferous (Pennsylvanian) coal-bearing strata. In the regional tectonic zone of the Bzie-Czechowice Fault, over 4 times higher average carbon dioxide concentrations were detected, in comparison with those analysed in the Jawiszowice Fault Zone. Carbon dioxide was of microbial origin, migrating from a secondary accumulation. Relatively low values of both the methane and carbon dioxide emissions were noticed at sampling sites, where elevated concentrations of both gases were encountered previously in the near-surface zone. This suggests that gases may accumulate in the near-surface zone as a result of long-term, and relatively slow migration from the depth. Hence, and in this case the potential gas hazard caused by uncontrolled and fast inflow of methane and carbon dioxide to a basements of buildings is insignificant. © 2019 Elsevier B.V.},

note = {11},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85059533655,

title = {Distribution of methane contents and coal rank in the profiles of deep boreholes in the Upper Silesian Coal Basin, Poland},

author = { S. Kędzior},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85059533655&doi=10.1016%2fj.coal.2018.12.010&partnerID=40&md5=6ca931fd39929680c5f4291303755716},

doi = {10.1016/j.coal.2018.12.010},

issn = {01665162},

year  = {2019},

date = {2019-01-01},

journal = {International Journal of Coal Geology},

volume = {202},

pages = {190-208},

publisher = {Elsevier B.V.},

abstract = {The central, western and southwestern parts of the Polish Upper Silesian Coal Basin (USCB) are characterized by elevated methane contents and coal ranging in rank from high-volatile bituminous to anthracite. Two patterns of methane distribution with depth have been recognized. The northern pattern involves a naturally outgassed zone and a primary methane interval below 600–800 m. The southern pattern comprises a secondary peak immediately below Miocene cover rocks and a deeper primary peak. A variety of factors influencing present-day methane contents make the distribution of methane at depth complex even in individual boreholes. An analysis of the depth trend of average methane contents reveals that, in some cases, the primary methane peak is divided into two smaller sub-peaks, the first coinciding with medium-volatile bituminous coal and the second typically with the transition from low-volatile bituminous coal to anthracite. The sub-maxima are separated by an interval of gradually decreasing methane content, usually in the direction towards low-volatile bituminous coals. Rapid increases in methane content with depth are probably related to the occurrence of medium-volatile bituminous coals that are, in turn, related to the second coalification jump at which coal loses ca. 10% of its volatiles, producing, inter alia, methane which is adsorbed by the coal. Low-volatile bituminous coal and anthracite are characterized by high methane contents due to further methane generation at this stage of the coalification process. Anthracite has a high methane content because of its high sorption capacity and high coal rank. Though basin evolution, temperature, and pressure (stress) are the key factors influencing the process of methane generation, coal sorption capacity for gases and present-day depth distribution of methane, other processes of gas migration and accumulation contribute to distribution patterns that are both variable and complex. © 2019 Elsevier B.V.},

note = {16},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-85027918251,

title = {Methane contents and coal-rank variability in the Upper Silesian Coal Basin, Poland},

author = { S. Kędzior},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85027918251&doi=10.1016%2fj.coal.2014.09.009&partnerID=40&md5=a57cb5004352b7afb0bde6a348b3c4da},

doi = {10.1016/j.coal.2014.09.009},

issn = {01665162},

year  = {2015},

date = {2015-01-01},

journal = {International Journal of Coal Geology},

volume = {139},

number = {1},

pages = {152-164},

publisher = {Elsevier B.V.},

abstract = {The process of coalification results in changes in both the chemical composition and physical properties of the coal. One of the most important stages in the development of bituminous coal is the so called "second coalification jump" corresponding to medium-volatile coals characterized by a significant decrease of volatile matter from 33% to 20% and the release of methane, carbon dioxide and water. In the Upper Silesian Coal Basin (USCB), the highest values of methane content (>12-14m3/t coal daf) range from 35-22% (Vdaf) and vitrinite reflectance (Rr) values from 0.84-1.50% range-in approximate accord with values defining the second coalification jump (Vdaf-29%; Rr-1.3%), i.e., coking coals. In the basin, the distribution of the top of high methane zone (4.5m3/t coal daf) is similar to that of the coking coals. That is why increasing methane contents towards the southern- and western parts of the basin can be explained by the increasing proportion of coking coals there. However, on a basin scale, correlations between present methane contents and individual parameters of coal rank are weak due, most likely, to late gas migration due, in turn, to factors unrelated to earlier coalification including, inter alia, tectonic disturbance and hydrodynamic processes. © 2014 Elsevier B.V.},

note = {38},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84879015379,

title = {Reservoir parameters and maceral composition of coal in different carboniferous lithostratigraphical series of the Upper Silesian Coal Basin, Poland},

author = { S. Kędzior and I. Jelonek},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84879015379&doi=10.1016%2fj.coal.2012.08.007&partnerID=40&md5=420892848418269db55cf943382e3ac2},

doi = {10.1016/j.coal.2012.08.007},

issn = {01665162},

year  = {2013},

date = {2013-01-01},

journal = {International Journal of Coal Geology},

volume = {111},

pages = {98-105},

publisher = {Elsevier B.V.},

abstract = {Laboratory tests were carried out on coal samples taken from mine openings of selected coal mines in the Upper Silesian Coal Basin. The analyses involved maceral composition (vitrinite; inertinite and liptinite group) and vitrinite reflectance on the one hand, and reservoir parameters (coal permeability and effective porosity) on the other. The results are compared. Samples with high values of coal permeability are characterized by vitrinite contents of ca 60%, and samples with the lowest permeability by vitrinite contents of 40%. The vitrinite-rich bright coals are brittle and prone to crushing caused by tectonic pressures. Moreover, coal permeability is more strongly anisotropic in the bright coals of the Cracow Sandstone and the Mudstone Series than in the dull coals of the Upper Silesian Sandstone Series. In bright coals, permeability is much along the direction parallel to vitrain layers. Good reservoir parameters such as permeability and effective porosity are crucial for fluid flow through the coal seams and, thus, successful coalbed methane exploitation. In the Upper Silesian Coal Basin, Cracow Sandstone- and Mudstone Series with vitrinite-rich coals should be a good target, though serious geological problems must first be overcome. © 2012 Elsevier B.V.},

note = {24},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-84871642504,

title = {Geology, spatial distribution of methane content and origin of coalbed gases in Upper Carboniferous (Upper Mississippian and Pennsylvanian) strata in the south-eastern part of the Upper Silesian Coal Basin, Poland},

author = { S. Kędzior and M.J. Kotarba and Z. Pekała},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84871642504&doi=10.1016%2fj.coal.2012.11.007&partnerID=40&md5=7c94b1a5796bb80836dd7fe0dfe4c990},

doi = {10.1016/j.coal.2012.11.007},

issn = {01665162},

year  = {2013},

date = {2013-01-01},

journal = {International Journal of Coal Geology},

volume = {105},

pages = {24-35},

abstract = {The subject of the investigation was both vertical and horizontal distribution of methane content in coal series within the south-eastern part of the Upper Silesian Coal Basin. In the study area coal deposits are characterized by various methane structures and varied spatial distribution of methane. "Brzeszcze" coal deposit located in the upthrow of Jawiszowice fault zone represents the so-called "open" methane pattern, in which the upper parts of coal-bearing series, to the depth of 300-500m (seam 327), are naturally degassed. Beneath, methane content rapidly increases with depth, and often achieves high values (between ten and twenty m3CH4/Mg coal daf). The area located to the south of Jawiszowice fault zone represents the so-called "closed" methane pattern, which means, that the primary methane zone was reworked due to the forming of Carpathian Foredeep in the Miocene period. A thick cover of Miocene claystones overlying the Carboniferous formations favors gas accumulation in the uppermost parts of the Carboniferous coal-bearing complex, especially in the roof elevations. Free methane occurs within the elevated part of porous and permeable Łaziska sandstones covered by Miocene claystones. The highest methane content characterizes the coal seams, which lie within Mudstone or Upper Silesian Sandstone Series. Smaller methane content is typical of the seams lying within Łaziska sandstones. The fault tectonics is another factor influencing the distribution of methane content, therefore, the large-size dislocations i.e. Jawiszowice and Bzie-Czechowice fault zones move the high-methane coal seams according to throw direction - southwards. The Carboniferous lithology, fault tectonics and also Miocene claystones covering the Carboniferous formations are the crucial factors influencing the various methane contents in the area discussed. Methane - the main component of gases accumulated in coal deposits and the minor components such as ethane, propane, butanes and carbon dioxide are of thermogenic origin that resulted from Variscan coalification, whereas the methane of the secondary accumulation in the uppermost part of Carboniferous formations beneath the impermeable Miocene cover contains a large microbial component, which is a result of Paleocene infiltration of meteoric waters with nutrients for methane bacteria into the coal series. © 2012 Elsevier B.V.},

note = {61},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-79954620589,

title = {The occurrence of a secondary zone of coal-bed methane in the southern part of the Upper Silesian Coal Basin (southern Poland): Potential for methane exploitation},

author = { S. Kędzior},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79954620589&doi=10.1016%2fj.coal.2011.01.003&partnerID=40&md5=cbd81b4f58ae313fdc71da19904266b5},

doi = {10.1016/j.coal.2011.01.003},

issn = {01665162},

year  = {2011},

date = {2011-01-01},

journal = {International Journal of Coal Geology},

volume = {86},

number = {2-3},

pages = {157-168},

abstract = {Coal-bed methane (CBM) exploitation in the Upper Silesian Coal Basin has, in spite of earlier failures, again aroused investor interest. Carboniferous coal seams at depths of 200-500m are characterized by coal permeability values (estimated at 27-230mD) and degrees of methane saturation (almost 100%) that suggest future successful exploitation. Based on the results of geological surveys archived in the Polish Geological Institute, the shallow CBM zone is defined as a gas horizon distinct from a deep CBM zone. The disposition of the shallow zone follows the topography of the Upper Carboniferous paleorelief, and, is deemed the most important factor controlling methane distribution within this zone. The most favorable places for CBM accumulation within the shallow coal seams are erosional highs and the slopes of Upper Carboniferous ridges associated with fault zones. The thickness of the zone (>200m) and methane contents (>8m3/t coal daf) are highest in these places. The nearly-full saturation of the coal seams with methane reflects the involvement of two genetic types of gas - indigenous late-stage microbial methane and thermogenic methane derived from the deeper coals. The favorable geological characteristic of this shallow CBM zone is a potential source of energy for Upper Silesia. © 2011 Elsevier B.V.},

note = {26},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-69949101369,

title = {Accumulation of coal-bed methane in the south-west part of the Upper Silesian Coal Basin (southern Poland)},

author = { S. Kędzior},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-69949101369&doi=10.1016%2fj.coal.2009.08.003&partnerID=40&md5=806c1a6f481fa290394a5c1ad028d405},

doi = {10.1016/j.coal.2009.08.003},

issn = {01665162},

year  = {2009},

date = {2009-01-01},

journal = {International Journal of Coal Geology},

volume = {80},

number = {1},

pages = {20-34},

abstract = {The archives of the Polish Geological Institute house a wealth of coal-bed methane (CBM) data from surface boreholes and excavations in coal from the deposits of the Upper Silesian Coal Basin (USCB). These data support a model for the origin of substantial methane accumulations in the south-west part of the basin that reflects the interplay of the factors controlling methane sorption capacity and those controlling methane content. The factors controlling the sorption capacity of coal include coal rank, temperature, pressure, moisture content and maceral composition. Methane-content controls include lithology, stratigraphy, tectonics, hydrogeology and mining activity. The nature of the coal-bearing Carboniferous horizons, the sorption/desorption properties of the coals, the disposition of faults and folds, the topography of the Carboniferous palaeosurface and the presence of an impermeable Miocene cover were key controls. The methane accumulated in coal seams and in their host rocks in settings comparable with those in which petroleum and gas deposits are trapped. © 2009 Elsevier B.V. All rights reserved.},

note = {85},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-52649092909,

title = {The geological aspect of the occurrence of high coalbed methane zone in pawłowice area (Upper Silesian Coal Basin) [Wystepowanie płytkiej strefy wysokometanowych pokładów wegla w rejonie pawłowic (Górnoślaskie Zagłebie Weglowe)]},

author = { S. Kędzior},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-52649092909&partnerID=40&md5=ac019a77ca4e8fbdc1f2471dc510bf91},

issn = {08676143},

year  = {2008},

date = {2008-01-01},

journal = {Biuletyn - Panstwowego Instytutu Geologicznego},

number = {429},

pages = {69-74},

abstract = {The article presents the distribution and extent of the shallow coalbed methane zone based on the methane bearing capacity data, obtained from surface bore-holes drilled in the Pawlowice area. The results of the analysis show that the relief of the top-Carboniferous surface strongly influenced the presence and layout of the shallow methane bearing zone in the study area.},

note = {1},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-34748909459,

title = {The natural occurrence of methane and the methods of its extraction from hard coal seams of selected USA coal basins, and the prospects for methane extraction in Poland - A report from the training course in the USA [Warunki naturalne wystepowania i metody eksploatacji metanu pokładów wegla w wybranych zagłebiach weglowych USA oraz możliwości rozwoju eksploatacji tego gazu w Polsce - Sprawozdanie z wyjazdu szkoleniowego do USA]},

author = { S. Kędzior and J. Hadro and J. Kwarciński and S. Nagy and M. Młynarczyk and R. Rostkowski and E. Zalewska},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-34748909459&partnerID=40&md5=70c738932f06b568758efba0597516da},

issn = {00332151},

year  = {2007},

date = {2007-01-01},

journal = {Przeglad Geologiczny},

volume = {55},

number = {7},

pages = {565-570},

abstract = {[No abstract available]},

note = {8},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{2-s2.0-0036994099,

title = {The influence of tectonic factor on methane bearing capacity in chosen areas of the Upper Silesian Coal Basin},

author = { S. Kędzior},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036994099&partnerID=40&md5=35cc208bcf8830b0ff8dcbe80e7100b8},

issn = {15079791},

year  = {2002},

date = {2002-01-01},

journal = {Polish Geological Institute Special Papers},

volume = {7},

pages = {143-148},

abstract = {The paper presents general information on variability of coalbed methane bearing capacity in tectonic zones, faults, rock fissures etc. Methane occurrences were compared in two tectonic zones of the Upper Silesian Coal Basin - the zone of fault-block tectonics and the folded one. The influence of big size faults (i.e. Bzie-Czechowice fault) and neighbouring fissures on methane bearing capacity is strongly marked in the zone of fault-block tectonics. The most important tectonic factors influencing the methane occurrence in the folded zone are Chwałowice and Jejkowice depressions and also Orlová and Michalkovice overthrusts. The methane bearing zones are parallel to Chwałowice and Jejkowice depressions bottom axis. Presence of Carpathian nappes intensifies rock fissuring process, which could involve the methane migration and cause degasification of coal seams lying under these nappes.},

note = {6},

keywords = {},

pubstate = {published},

tppubtype = {article}

}