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| Titel |
The Inherent Tracer Fingerprint of Captured CO2 |
| VerfasserIn |
Stephanie Flude, Domokos Gyore, Finlay Stuart, Adrian Boyce, Stuart Haszeldine, Rick Chalaturnyk, Stuart Gilfillan |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250149698
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| Publikation (Nr.) |
 EGU/EGU2017-14074.pdf |
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| Zusammenfassung |
| Inherent tracers, the isotopic and trace gas composition of captured CO2 streams, are
potentially powerful tracers for use in CCS technology [1,2]. Despite this potential, the
inherent tracer fingerprint in captured CO2 streams has yet to be robustly investigated and
documented [3]. Here, we will present the first high quality systematic measurements of the
carbon and oxygen isotopic and noble gas fingerprints measured in anthropogenic CO2
captured from combustion power stations and fertiliser plants, using amine capture,
oxyfuel and gasification processes, and derived from coal, biomass and natural gas
feedstocks.
We will show that δ13C values are mostly controlled by the feedstock composition, as
expected. The majority of the CO2 samples exhibit δ18O values similar to atmospheric O2
although captured CO2 samples from biomass and gas feedstocks at one location in the UK
are significantly higher. Our measured noble gas concentrations in captured CO2
are generally as expected [2], typically being two orders of magnitude lower in
concentration than in atmospheric air. Relative noble gas elemental abundances are
variable and often show an opposite trend to that of a water in contact with the
atmosphere.
Expected enrichments in radiogenic noble gases (4He and 40Ar) for fossil fuel derived
CO2 were not always observed due to dilution with atmospheric noble gases during the CO2
generation and capture process. Many noble gas isotope ratios indicate that isotopic
fractionation takes place during the CO2 generation and capture processes, resulting in
isotope ratios similar to fractionated air. We conclude that phase changes associated with CO2
transport and sampling may induce noble gas elemental and isotopic fractionation, due to
different noble gas solubilities between high (liquid or supercritical) and low (gaseous)
density CO2.
Data from the Australian CO2CRC Otway test site show that δ13C of CO2 will
change once injected into the storage reservoir, but that this change is small and can
be quantitatively modelled in order to determine the proportion of CO2 that has
dissolved into the formation waters. Furthermore, noble gas data from the Otway
storage reservoir post-injection, shows evidence of noble gas stripping of formation
water and contamination with Kr and Xe related to an earlier injection experiment.
Importantly, He data from SaskPower’s Aquistore illustrates that injected CO2 will inherit
distinctive crustal radiogenic noble gas fingerprints from the subsurface once injected
into an undisturbed geological storage reservoir, meaning this could be used to
identify unplanned migration of the CO2 to the surface and shallow subsurface
[4].
References
[1] Mayer et al., (2015) IJGGC, Vol. 37, 46-60 http://dx.doi.org/10.1016/j.ijggc.2015.02.021
[2] Gilfillan et al., (2014) Energy Procedia, Vol. 63, 4123-4133
http://dx.doi.org/10.1016/j.egypro.2014.11.443
[3] Flude et al., (2016) Environ. Sci. Technol., 50 (15), pp 7939–7955 DOI:
10.1021/acs.est.6b01548
[4] Gilfillan et al., (2011) IJGGC, Vol. 5 (6) 1507-1516 http://dx.doi.org/10.1016/j.ijggc.2011.08.008 |
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