Characterization of Porosity and Pore Accessibility of Vitrinite-Rich Bituminous and Subbituminous Coals by Small-Angle Neutron Scattering, Mercury Intrusion Porosimetry, and Low-Pressure N₂ Adsorption

Three bituminous and one subbituminous vitrinite-rich coals were characterized using small-angle neutron scattering with contrast matching, mercury intrusion porosimetry, and low-pressure N₂adsorption techniques to quantify their porosity and pore accessibility in an effort to assess their solvent extractabilities, as a first approximation, for manufacturing useful end-products. The techniques revealed consistent results while complimenting one another. The total porosity was found to follow the coal rank with the lowest rank having the highest porosity within the studied coals. The amount of inaccessible pores was found to increase with rank for the bituminous coals studied here. The increase in the ease of accessibility and total porosity with decreasing rank suggested easier penetration of chemical reagents for solvent extraction, for example.