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Dynamical Behavior of Hydrocarbons Under Nanopore Confinement


EMSL Project ID
47739

Abstract

It is becoming increasingly clear that organic molecules present as gas species, in aqueous and mixed-volatile fluids - ranging from simple hydrocarbons and carboxylic acids to branched and cyclic compounds, to proteins and humic substances - play major roles in controlling geochemical processes, not just at Earth's surface, but also deep within the crust and mantle. Indeed, a key goal in geochemistry is to develop a comprehensive understanding of the thermophysical properties, structures, dynamics, and reactivity of complex geologic fluids and molecules (water and other C-H-O-N-S fluids, electrolytes, and organic-biological molecules) at multiple length scales (molecular to macroscopic) over wide ranges of temperature, pressure, and composition. This knowledge is foundational to advances in the understanding of geochemical processes involving mineral-fluid interfaces and reactions, and is applicable to problems addressed by both the EMSL Geochemistry/Biogeochemistry and Subsurface Science Theme and the Science of Interfacial Phenomena Science Theme.

The overarching goal of our BES-funded project is to obtain a fundamental, molecular-level understanding of the sorptivity, structure and dynamics of natural hydrocarbon (HC)-bearing volatile fluids at mineral surfaces or within nanoporous matrices over temperatures, pressures and compositions encountered in near-surface and shallow crustal environments. We will focus primarily on the behavior of C-H volatiles including methane and propane (two of the dominant gases observed in conventional natural gas accumulations as well as unconventional gas). We propose to use EMSL's world-class MAS NMR systems to quantify the mobility and interactions of methane and propane under nano-confinement in mesoporous silica, alumina and carbon as a function of pressure (density) and temperature. This team effort is linked to complementary quasielastic and inelastic neutron scattering (QENS; INS) experiments conducted at ORNL/SNS and to a MD effort through our collaboration with BES co-PI Prof. Alberto Striolo at Oklahoma University.

Project Details

Start Date
2012-11-30
End Date
2013-09-30
Status
Closed

Team

Principal Investigator

Karl Mueller
Institution
Pacific Northwest National Laboratory

Co-Investigator(s)

David Cole
Institution
The Ohio State University

Team Members

Salim Ok
Institution
The Ohio State University

Amity Andersen
Institution
Environmental Molecular Sciences Laboratory

David Hoyt
Institution
Environmental Molecular Sciences Laboratory