Ionization in H2O -- bearing carbon dioxide determined by conductivity measurements

Recent studies report rapid corrosion of metals and carbonation of minerals in contact with H2O-saturated (or nearly saturated) CO2. One explanation for this behavior is that addition of small amounts of H2O to CO2 leads to significant ionization within the fluid (analogous to corrosion in aqueous fluids). The extent of ionization in the bulk CO2 fluid was determined using a flow-through conductivity cell capable of analyzing very dilute solutions. Experiments were conducted from 25 to 200"C and 25 to 200 bar with H2O concentrations up to ~1650 ppmw. In all experiments, conductivities <10 nS/cm were obtained, indicating that the solution is essentially ion-free. This observation suggests that mobile ions are not present in the bulk CO2--rich fluid, and that the observed corrosion and carbonation reactions are not the result of ionization in the bulk fluid.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Geosciences

Department dc:contributor.department

Geosciences

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2013

Author dc:creator

• Capobianco, Ryan Michael

Chair dc:contributor.committeechair

• Bodnar, Robert J.

Committee members dc:contributor.committeemember

• Gruszkiewicz, Kiroslaw S.
• Rimstidt, J. Donald

• carbon dioxide
• corrosion
• carbon capture and sequestration
• enhanced geothermal energy
• carbonic acid

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

vt_gsexam:599

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/23283