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| Titel |
Quantifying chemical and petrophysical alterations in porous materials by CO2 using HRXCT |
| VerfasserIn |
Marijn Boone, Veerle Cnudde, Mieke Quaghebeur, Helga Ferket |
| 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 |
250055244
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| Zusammenfassung |
| Geological sequestration of CO2 is a transitional solution to reduce the concentration of
greenhouse gases in the atmosphere pending sufficient renewable energy alternatives. CO2
can also be used as raw product for industrial processes whereby CO2 is sequesterd and
new materials are formed. Carbonation can be used to stabilize mineral waste or
even be transformed into innovative materials. Understanding the mineral-CO2
interactions is essential in the advances of the carbonation process and the upscaling of
geological storage. Accurately translating chemical data from reactor experiments and
petrophysical data of reservoir rocks to a model for reactive transport is often a
challenging step. This is mainly due to the complexity of the used reservoir rocks in
the experiments, resulting in a model that cannot be univocally calibrated or even
validated.
This research starts from a clear, verifiable design, in order to unravel the processes that
occur when a CO2-enriched fluid reacts with different mineral phases in porous media. To
comprehend the chemical properties and the kinetics of the reactions, individual minerals are
exposed to a CO2-enriched fluid in batch reactors. To analyze the physico-chemical
changes (the “diagenesis” of the rock), artificial porous rocks are created from
these individual minerals with controllable petrophysical parameters (for example:
porosity, permeability, reactive surface, composition) using 3D fiber deposition or
other techniques. By using 3D fiber deposition, a homogenous rectangular structure
is made, which is ideal for up scaling and modeling of reactive processes. These
homogenous artificial rocks are then exposed to a CO2-enriched fluid in batch and flow
through reactors and analyzed using traditional methods and High Resolution X-ray
Computed Tomography (HRXCT). HRXCT is a nondestructive technique that allows a
complete characterization of the artificial rocks in 3D up to sub-micron resolution
(400 nm). The 3D images from the HRXCT are then used as a verification basis
for reactive transport models through porous media. Furthermore, because of the
nondestructive nature of the technique, the changes (dissolution/precipitation) in the artificial
samples due to the exposure to a CO2-enriched fluid, are analyzed on the same sample
and the mineral-CO2 interactions can be quantified through time. By combining
these experimental results on the same samples through time with the models for
reactive transport through porous media, the models can be validated and eventually
calibrated. This will later on help to understand more complex experiments on real
reservoir materials and will allow the optimization of the carbonation processes for the
stabilization of mineral waste and the production of innovative building materials. |
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