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| Titel |
Modelling tar pollutant production and solubility in the frame of UCG with combined CO2 storage |
| VerfasserIn |
Stefan Klebingat, Rafig Azzam, Thomas Kempka, Ralph Schlüter, Marc Schulten, Peter Quicker, Christoph Neukum, Tomás Fernández-Steeger |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250050050
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| Zusammenfassung |
| Facing the ongoing depletion of traditional energy ressources underground coal
gasification (UCG) with combined CO2 storage is a sustainable approach with positive
economic potential (KEMPKA et al. 2009). Industrial UCG applications focus the
production of a high calorific product gas, simultaneously undesired by-products
have to be minimized to maintain the environmental safety in the aboveground and
underground ambience. Considering the underground system the estimation of
in-process generated tar pollutant quantities and its discharge into the adjacent
groundwater system under in-situ conditions is a major challenge that still remains
unsolved by now (SURY et al 2004, FRIEDMAN et al. 2009). Tars generally comprise a
complex pollutant spectrum with up to 10.000 single species (FRANK & COLLIN
1968). Information on tar data from past UCG field trials is rare and where available
often precise data on single compound quantities generated in the pyrolysis and
gasification zone are missing. Analyzing the bulk tar production quantitatively
pyrolysis seems to be the dominant tar generating process (STEPHENS & THORSNESS
1985).
Against this environmental background a thermodynamic model for in-process generated
tar single pollutant quantities under consideration of site specific UCG-reactor zones and trial
conditions is currently developed and validated against past field trial data in the frame of the
national joint project CO2SINUS, funded by the Federal Ministry of Education and Research
(BMBF), Germany. In the frame of a multi parameter study the following input
parameters are analysed regarding their influence on tar single pollutant output
production:
Coal chemistry and volume-streams
In-situ pressure and temperature conditions
Reactor water influx from the adjacent overburden
Reactor heat losses
The results gained out of these scenario calculations are used as input data for the
parameterization of a separately developed tar-groundwater-CO2 solubility model
considering single tar pollutant groups. In this context a special focus is set on
pressure-dependent solubility changes for deep coal deposits (1 to 5 km), reflecting the
European bituminous coal conditions.
The benefit of both model approaches together will allow a single pollutant precise
aqueous tar solubility prognosis for planned UCG projects under consideration of site specific
boundary conditions (coal type, (hydro-)geology, deposit pressure and temperature, water and
heat streams) as well operative tasks, e.g. the scheduled product gas mix. A step ahead the
environmental long-term groundwater risk of future UCG applications can be estimated using
the pollutant distribution data as input stream for upcoming pollutant transport
models.
References
FRANK, H.-G.,COLLIN G. (1968): Steinkohlenteer; Chemie, Technologie und
Verwendung – 245 S. Berlin, Heidelberg, New York (Springer).
FRIEDMANN, J., UPADHYE R., KONG, F.-M. (2009): Prospects for underground coal
gasification in carbon-constrained world. – Energy Procedia 1, 2009, 4551–4557.
KEMPKA, T., NAKATEN, N., SCHLüTER, R., AZZAM, R. Â (2009): Wirtschaftlichkeit
der in-situ Kohleumwandlung mit angegliederter CO2-Speicherung - In: Glückauf 154Â (5),
248-255.
STEPHENS, D.R., THORSNESS, C.B. (1985): Partial Seam CRIP test tar results. –
Proceedings of the 11th Annual Underground Coal Gasification Symposium, pages 179-199,
Morgantown, West Virginia, August 1985.
SURY, M., WHITE, M., KIRTON, J., CARR, P., WOODBRIDGE, R., MOSTADE, M.,
CHAPPELL, R., HARTWELL, D., HUNT, D., RENDELL, N. (2004): Review of
Environmental Issues of UCG, Report - No. COAL R272 DTI/Pub URN 04/1880, November
2004. |
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