Spatial distribution and origin of coalbed gases at the working faces of the Velenje Coal Basin, Slovenia, since the year 2000

Geochemical and isotopic monitoring of coalbed gases at the excavation fields of mining areas in Velenje Coal Basin, Slovenia, has been ongoing since the year 2000 with the aim of obtaining better insights into the distribution and origin of coalbed gases. Results from the mining areas Pesje and Preloge (active excavation fields) are presented here from the year 2000 up to the present. Composition and origin of coalbed gases were determined using mass spectrometry at the Jožef Stefan Institute. From a larger database of geochemical samples, 119 samples were used for analysis and spatial presentation in a geographical information system (GIS) environment. We have used geochemical (CH4, CO2 and N2) and isotopic (δ13CCO2 and δ13CCH4) tracers for geochemical and isotopic characterisation of coalbed gases from the active excavation fields. Concentrations of CO2 and the carbon dioxide–methane indices in the southern part of the basin are higher than in the northern part of the basin due to the vicinity of the active Šoštanj Fault. The value of δ13CCH4 at the active excavation field indicates a bacterial origin, with values greater than –50‰, and only some boreholes show elevated δ13CCH4 quantities as a consequence of the CO2 reduction process in Velenje Coal Basin. The value of δ13CCO2 indicates the bacterial and endogenic origin of carbon

Underground coal gasification - the Velenje Coal Mine energy and economic calculations

Underground coal gasification (UCG) is a viable possibility for the exploitation of vast coal deposits that are unreachable by conventional mining and can meet the energy, economic and environmental demands of the 21st century. Due to the complexity of the process, and the site-specific coal and seam properties, it is important to acknowledge all the available data and past experiences, in order to conduct a successful UCG operation. Slovenia has huge unmined reserves of coal, and therefore offers the possibility of an alternative use of this domestic primary energy source. According to the available underground coal gasification technology, the energy and economic assessment for the exploitation of coal to generate electricity and heat was made. A new procedure for the estimation of the energy efficiency of the coal gasification process, which is also used to compare the energy analyses for different examples of coal exploitation, was proposed, as well as the technological schemes and plant operating mode in Velenje, and the use of produced synthetic coal gas (syngas). The proposed location for the pilot demonstration experiment in Velenje Coal Mine was reviewed and the viability of the underground coal gasification project in Velenje was determined

Podzemna gasifikacija uglja - energetski i ekonomski proračuni za rudnik uglja Velenje

Underground coal gasification (UCG) is a viable possibility for the exploitation of vast coal deposits that are unreachable by conventional mining and can meet the energy, economic and environmental demands of the 21st century. Due to the complexity of the process, and the site-specific coal and seam properties, it is important to acknowledge all the available data and past experiences, in order to conduct a successful UCG operation. Slovenia has huge unmined reserves of coal, and therefore offers the possibility of an alternative use of this domestic primary energy source. According to the available underground coal gasification technology, the energy and economic assessment for the exploitation of coal to generate electricity and heat was made. A new procedure for the estimation of the energy efficiency of the coal gasification process, which is also used to compare the energy analyses for different examples of coal exploitation, was proposed, as well as the technological schemes and plant operating mode in Velenje, and the use of produced synthetic coal gas (syngas). The proposed location for the pilot demonstration experiment in Velenje Coal Mine was reviewed and the viability of the underground coal gasification project in Velenje was determined.Podzemna gasifikacija uglja (PGU) je održiva mogućnost za eksploataciju ogromnih ležišta uglja koji su nedostupni konvencionalnom rudarstvu i može da zadovolji energetske, ekonomske i ekološke zahteve 21. veka. Zbog složenosti procesa, specifičnosti nalazišta i svojstva slojeva uglja, veoma je važno da se poznaju svi raspoloživi podaci i iskustva iz prošlosti, radi uspešnog obavljanja PGU operacije. Slovenija ima ogromne neiskopane rezerve uglja, i zato nudi mogućnost alternativnog korišćenja ovog domaćeg primarnog izvora energije. Prema dostupnoj tehnologiji za podzemnu gasifikaciju uglja, napravljena je energetska i ekonomska procena eksploatacije uglja za generisanje električne energije i toplote. Predložen je novi postupak za procenu energetske efikasnosti procesa gasifikacije uglja, koji je korišćen za uporednu analizu različitih primera eksploatacije uglja , kao i tehnološke šeme i način rada postrojenja u Velenju za proizvodnju sinteznog ugljenog gasa (singas). Pregledana je predložena lokacija za pilot demonstracioni eksperiment u rudniku uglja Velenje i utvrđena je održivost projekta PGU u Velenju