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A hyperbaric AFM for imaging mineral surfaces in supercritical CO2


EMSL Project ID
32092

Abstract

Storage of anthropogenic carbon dioxide (CO2) in deep underground saline aquifers has been proposed as a viable method of slowing the increase of CO2 in the earthâ??s atmosphere while continuing to allow the use of fossil-C based fuels for energy. In these aquifers, the CO2 will exist in the supercritical state. Consequently, numerous bulk laboratory studies are underway to measure the thermodynamic and kinetic properties of the reactions that would occur for various mineral systems in the presence of hydrous, supercritical CO2. Yet, the molecular-scale, site-specific reactions that take place at these mineral-fluid interfaces are entirely unknown. These fundamental reactions ultimately sum to produce the interfacial phenomena that are observed in bulk studies and described macroscopically by equilibrium thermodynamics or kinetic rate laws. Attempts to understand and control the chemistry at these interfaces, which is necessary to assess the practicality of subsurface carbon sequestration, should be based on explicit and quantitative understanding of these fundamental interactions. To address this, we propose to build and test a hyperbaric atomic force microscope that is capable of imaging mineral-H2O-supercritical CO2 systems in situ and in real-time on a molecular-scale. This instrument will be based on the hyperbaric, hyperthermal AFM that has been developed in recent years, but will be able to handle the pressures necessary to operate with supercritical CO2. Calcite will be utilized as a test specimen to facilitate the development of the system. To be fully operational, this instrumentation will need to be interfaced with the Nanoscope IIIa scanning probe in the Interfacial and Nanoscale Science Facility.

Project Details

Start Date
2009-03-31
End Date
2010-04-04
Status
Closed

Team

Principal Investigator

Scott Lea
Institution
Environmental Molecular Sciences Laboratory

Team Members

James Amonette
Institution
Pacific Northwest National Laboratory

Related Publications

Lea AS, SR Higgins, KG Knauss, and KM Rosso. 2011. "A high-pressure atomic force microscope for imaging in supercritical carbon dioxide." Review of Scientific Instruments 82(4):Article No.: 043709.