Reactivity of Iron-Bearing Minerals Under Carbon Sequestration Conditions

The rise in anthropogenic carbon dioxide in the atmosphere has caused the pursuit of adequate methods to alleviate the resulting strain on the world's ecosystem. A promising strategy is the geological sequestration of carbon dioxide, in which carbon dioxide emitted from large point sources is injected underground for storage. Under storage, carbon dioxide trapped as a carbonate mineral may be stable for geological time periods. Experiments were conducted to test the potential of ferric-bearing minerals to sequester carbon as a ferrous carbonate mineral (siderite). The formation of siderite requires the reduction of ferric ions which may be achieved by the co-injection of H2S or SO2 contaminants with CO2. Both ferrihydrite and hematite nanoparticles were exposed to an aqueous Na2S solution in the presence of supercritical CO2 (scCO2) and were analyzed in situ by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). In situ ATR-FTIR indicated that the formation of siderite occurred on the order of minutes for ferrihydrite and hematite nanoparticles. Particles were analyzed post-reaction with X-ray diffraction (XRD) and electron microscopy. XRD results indicated that ferrihydrite reacted completely to form siderite and elemental sulfur after 24 h at 100 °C, while hematite only partially reacted to form siderite and pyrite after 24 h at 70 °C. Additionally, hematite nanoparticles were exposed to H2S and scCO2 in a series of batch reactions, and the reaction products were determined by XRD as a function of CO2 and H2S partial pressures, alkalinity, salinity, time, and temperature.

Grantor dc:publisher

Temple University. Libraries

Year dc:date.issued

2011

Author dc:creator

• Murphy, Riley Tomas

Advisor dc:contributor.advisor

• Strongin, Daniel R.

Committee members dc:contributor.committeemember

• Stanley, Robert J.
• Wunder, Stephanie L.
• Schoonen, Martin A. A., 1960-

• Chemistry
• Geochemistry
• Hematite
• Sequestration
• Sulfide
• Supercritical

Statement dc:rights

• IN COPYRIGHT- This Rights Statement can be used for an Item that is in copyright. Using this statement implies that the organization making this Item available has determined that the Item is in copyright and either is the rights-holder, has obtained permission from the rights-holder(s) to make their Work(s) available, or makes the Item available under an exception or limitation to copyright (including Fair Use) that entitles it to make the Item available.

Licence dc:rights.uri

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

Language dc:language.iso

eng

Dc Identifier Other

864885238

OAI identifier oai:identifier

oai:scholarshare.temple.edu:20.500.12613/1976