NETL Researchers Develop Method to Estimate CO₂ Storage
Capacity in Oriskany Formation

	Robert Dilmore, a researcher at NETL, assembles a pressure vessel reactor to place in the hydrothermal rocking autoclave. Dilmore is part of a team of scientists investigating carbon dioxide/water/rock interaction for carbon dioxide storage in deep saline aquifers and other geological formations.

As part of NETL’s ongoing research into geologic sequestration of anthropogenic carbon dioxide, results of an investigation into solubility capacity of the Oriskany Sandstone brine aquifer will appear in an upcoming special edition of the American Chemical Society journal Environmental Science and Technology.

Rocking autoclave reactors were used to measure the solubility of carbon dioxide in real brines of the Oriskany formation at in situ conditions, and these data were used to validate a model.

Using available geospatial data, this empirically-verified model was applied within a geographic information system to develop an estimate of the solubility capacity of carbon dioxide in the Oriskany formation: 0.36 gigatons of carbon dioxide.

This estimate provides a low-boundary of formation capacity, as compared to a volumetric (free-phase) supercritical carbon dioxide capacity estimated to be approximately 8.8 gigatons.

NETL Conducts Systematic Study of Carbon Dioxide Adsorbents

	Jeff Culp, a researcher at NETL, examines a sample of carbon dioxide adsorbents composed of layers and pillars which may find applications in such technologies as gas purification, gas storage, and sensors.

In the continuing search for better adsorbents for carbon dioxide, the relationship between performance and molecular structure becomes a key guiding principle.

NETL researchers have conducted a thorough study of the relationship between performance and molecular structure of a series of carbon dioxide adsorbents composed of layers and pillars.

The adsorbents consist of sheet-like ionic metal complexes held apart by pillars of organic compounds.  The pillars are specifically chosen to be of different lengths and to be more or less flexible. Carbon dioxide storage capacity was related to the relative size of the pores and greater capacity was associated with pillars of greater length.  The adsorption strength was strongly affected by whether the pillars were rigid or flexible.  The adsorbent made with the most flexible pillar had a collapsed pore structure that was ineffective in adsorbing carbon dioxide while those made with rigid pillars had open pores that readily took in carbon dioxide.

The pillared layered architecture has been found to be an excellent scaffold on which to study the effect of molecular structure on adsorbent behavior. This technique is now being extended by investigating the effect of attaching organic functional groups with stronger affinity for carbon dioxide to the pillars.

The study of the relationship between performance and molecular structure of carbon dioxide adsorbents is being reported in a manuscript to be submitted to the Journal of the American Chemical Society.

NETL Researchers Identify Major Failure Mechanism of Chromia Refractories in Slagging Gasifiers

	An NETL researcher conducts a rotary slag test to study the effect of gasifier operating conditions and carbon feedstock slag/ash chemistry on the refractory service life of chromia refractories in slagging gasifiers.

NETL researchers have studied the effect of gasifier operating conditions and carbon feedstock slag/ash chemistry on the refractory service life of chromia refractories in slagging gasifiers.

They identified structural spalling as one of major failure mechanisms for chromia refractories.  In a paper published in the International Journal of Applied Ceramic Technology, the researchers also presented the development of a refractory designed by NETL to withstand spalling and enhance refractory performance.