Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Estimation and modeling of coal pore accessibility using small angle neutron scattering

Journal Article · · Fuel
 [1];  [2];  [2];  [1];  [2];  [2];  [1]
  1. Pennsylvania State Univ., University Park, PA (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Gas diffusion in coal is controlled by nano-structure of the pores. The interconnectivity of pores not only determines the dynamics of gas transport in the coal matrix but also influences the mechanical strength. In this study, small angle neutron scattering (SANS) was employed to quantify pore accessibility for two coal samples, one of sub-bituminous rank and the other of anthracite rank. Moreover, a theoretical pore accessibility model was proposed based on scattering intensities under both vacuum and zero average contrast (ZAC) conditions. Our results show that scattering intensity decreases with increasing gas pressure using deuterated methane (CD4) at low Q values for both coals. Pores smaller than 40 nm in radius are less accessible for anthracite than sub-bituminous coal. On the contrary, when the pore radius is larger than 40 nm, the pore accessibility of anthracite becomes larger than that of sub-bituminous coal. Only 20% of pores are accessible to CD4 for anthracite and 37% for sub-bituminous coal, where the pore radius is 16 nm. For these two coals, pore accessibility and pore radius follows a power-law relationship.
Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1265817
Alternate ID(s):
OSTI ID: 1247723
Journal Information:
Fuel, Journal Name: Fuel Journal Issue: C Vol. 161; ISSN 0016-2361
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (44)

Failure mechanisms in coal: Dependence on strain rate and microstructure: FAILURE MECHANISMS IN COAL journal September 2014
Evaluation of in situ stress changes with gas depletion of coalbed methane reservoirs journal August 2014
Determination of the Effective Stress Law for Deformation in Coalbed Methane Reservoirs journal October 2013
Study of structural change in Wyodak coal in high-pressure CO2 by small angle neutron scattering journal June 2010
Nature of the porosity in American coals journal October 1972
Application of small-angle neutron scattering (SANS) to the study of coal porosity journal September 1983
Coal microstructure and micropermeability and their effects on natural gas recovery journal January 1993
The effect of pore structure and gas pressure upon the transport properties of coal: a laboratory and modeling study. 1. Isotherms and pore volume distributions journal September 1999
The pore structure of the Argonne coals as interpreted from contrast matching small angle neutron scattering journal September 2000
Small angle neutron scattering signature of oil generation in artificially and naturally matured hydrocarbon source rocks journal January 2000
Water vapour adsorption in highly porous carbons as seen by small and wide angle X-ray scattering journal April 2010
Characterization of accessible and inaccessible pores in microporous carbons by a combination of adsorption and small angle neutron scattering journal July 2012
Application of SAXS and SANS in evaluation of porosity, pore size distribution and surface area of coal journal August 2004
Swelling-induced volumetric strains internal to a stressed coal associated with CO2 sorption journal November 2007
Gas diffusion behavior of coal and its impact on production from coalbed methane reservoirs journal June 2011
Pore size distribution and accessible pore size distribution in bituminous coals journal October 2012
Development of the meso- and macroporous structure of coals with rank as analysed with small angle neutron scattering and adsorption experiments journal March 2004
Adsorption of methane, nitrogen, carbon dioxide and their mixtures on wet Tiffany coal journal December 2005
Accessibility of pores in coal to methane and carbon dioxide journal January 2012
Laboratory measurement and modeling of coal permeability with continued methane production: Part 2 – Modeling results journal April 2012
Characterization of tight gas reservoir pore structure using USANS/SANS and gas adsorption analysis journal May 2012
Pore structure characterization of North American shale gas reservoirs using USANS/SANS, gas adsorption, and mercury intrusion journal January 2013
Pore Structure of the Argonne Premium Coals journal March 1995
Methods for Characterization of Inorganic and Mineral Matter in Coal:  A Critical Overview journal March 2003
Methane/CO 2 Sorption Modeling for Coalbed Methane Production and CO 2 Sequestration journal July 2006
Pore Accessibility by Methane and Carbon Dioxide in Coal as Determined by Neutron Scattering journal February 2012
Porosity of Coal and Shale: Insights from Gas Adsorption and SANS/USANS Techniques journal July 2012
A USANS/SANS Study of the Accessibility of Pores in the Barnett Shale to Methane and Water journal February 2013
Wettability Evaluation of a CO 2 /Water/Bentheimer Sandstone System: Contact Angle, Dissolution, and Bubble Size journal May 2014
Pore Structure Characterization of Coal by Synchrotron Small-Angle X-ray Scattering and Transmission Electron Microscopy journal May 2014
Hierarchical Pore Morphology of Cretaceous Shale: A Small-Angle Neutron Scattering and Ultrasmall-Angle Neutron Scattering Study journal September 2014
Small-Angle and Ultrasmall-Angle Neutron Scattering (SANS/USANS) Study of New Albany Shale: A Treatise on Microporosity journal January 2015
Scattering by an Inhomogeneous Solid journal June 1949
The determination of the void structure of microporous coals by small‐angle neutron scattering: Void geometry and structure in Illinois No. 6 bituminous coal journal February 1986
Small-Angle X-Ray-Scattering Investigation of Submicroscopic Porosity with Fractal Properties journal August 1984
Reduction and analysis of SANS and USANS data using IGOR Pro journal November 2006
The 40 m general purpose small-angle neutron scattering instrument at Oak Ridge National Laboratory journal August 2012
Absolute calibration of small-angle neutron scattering data journal February 1987
Compressibility of sorptive porous media: Part 1. Background and theory journal September 2014
Compressibility of sorptive porous media: Part 2. Experimental study on coal journal September 2014
A new theoretical approach to model sorption-induced coal shrinkage or swelling journal July 2013
Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry journal January 1972
Capillary Pressure and Wettability Behavior of CO2 Sequestration in Coal at Elevated Pressures journal December 2008
Small-Angle Neutron Scattering and the Microstructure of Rocks journal January 2006

Cited By (4)


Similar Records

Pore size distribution and accessible pore size distribution in bituminous coals
Journal Article · Sat Dec 31 23:00:00 EST 2011 · International Journal of Coal Geology · OSTI ID:1049088

Pore accessibility and trapping of methane in Marcellus shale
Journal Article · Mon Sep 13 20:00:00 EDT 2021 · International Journal of Coal Geology · OSTI ID:1827291

Pore accessibility by methane and carbon dioxide in coal as determined by neutron scattering
Journal Article · Sat Dec 31 23:00:00 EST 2011 · Energy & Fuels · OSTI ID:1045224