Porosity of coal and shale: Insights from gas adsorption and SANS/USANS techniques

Journal Article · Sun Jan 01 04:00:00 EST 2012 · International Journal of Coal Geology

DOI:https://doi.org/10.1021/ef300735t· OSTI ID:1049091

Mastalerz, Maria ^[1]; He, Lilin ^[2]; Melnichenko, Yuri B ^[2]; Rupp, John A ^[2]

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1. Indiana Geological Survey
2. ORNL

Two Pennsylvanian coal samples (Spr326 and Spr879-IN1) and two Upper Devonian-Mississippian shale samples (MM1 and MM3) from the Illinois Basin were studied with regard to their porosity and pore accessibility. Shale samples are early mature stage as indicated by vitrinite reflectance (R{sub o}) values of 0.55% for MM1 and 0.62% for MM3. The coal samples studied are of comparable maturity to the shale samples, having vitrinite reflectance of 0.52% (Spr326) and 0.62% (Spr879-IN1). Gas (N{sub 2} and CO{sub 2}) adsorption and small-angle and ultrasmall-angle neutron scattering techniques (SANS/USANS) were used to understand differences in the porosity characteristics of the samples. The results demonstrate that there is a major difference in mesopore (2-50 nm) size distribution between the coal and shale samples, while there was a close similarity in micropore (<2 nm) size distribution. Micropore and mesopore volumes correlate with organic matter content in the samples. Accessibility of pores in coal is pore-size specific and can vary significantly between coal samples; also, higher accessibility corresponds to higher adsorption capacity. Accessibility of pores in shale samples is low.

• Research Organization: Oak Ridge National Laboratory (ORNL); High Flux Isotope Reactor
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1049091
• Journal Information: International Journal of Coal Geology, Journal Name: International Journal of Coal Geology Journal Issue: 8 Vol. 23; ISSN ENFUEM; ISSN 0887-0624
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ADSORPTION
CAPACITY
COAL
DISTRIBUTION
ILLINOIS BASIN
NEUTRONS
ORGANIC MATTER
POROSITY
SCATTERING
SHALES
VITRINITE