Stability of the Bituminous Coal Microstructure upon Exposure to High Pressures of Helium

Abstract

Small-angle neutron scattering (SANS) and ultra-small-angle neutron scattering (USANS) measurements of the structure of two Australian bituminous coals (particle size of 1-0.5 mm) before, during, and after exposure to 155 bar of helium were made to identify any effects of pressure alone on the pore size distribution of coal and any irreversible effects upon exposure to high pressures of helium in the pore size range from 3 nm to 10 μm. No irreversible effects upon exposure were identified for any pore size. No effects of pressure on pore size distribution were observed, except for a small effect at a pore size of about 2 μm for one coal. This study provides a convenient baseline for SANS and USANS investigations on sorption of gases at elevated pressures on coals, by distinguishing between the effect of pressure alone on coal pore size distribution and against the effect of the gas to be investigated.

Characterization and Analysis of Porosity and Pore Structures

“…Schmidt 1989;Radlinski 2006), including: coals and hydrocarbon source rocks (Bale and Schmidt 1984;Reich et al 1990;Haenel 1992;Radlinski et al 1996Radlinski et al , 2000aRadlinski et al ,b, 2004Sastry et al 2000;Sen et al 2001Sen et al , 2002aMcMahon et al 2002;Prinz et al 2004;Avdeev et al 2006;Connolly et al 2006;Radlinski 2006;Mares et al 2009;Melnichenko et al 2009Melnichenko et al , 2012Sakurovs et al 2009;Mastalerz et al 2012Mastalerz et al , 2013Cai et al 2014;Thomas et al 2014), sandstones, shales, and carbonates (Hall et al 1983Wong and Howard 1986;Triolo et al 2000Triolo et al , 2006Sen et al 2002b;Lebedev et al 2004Lebedev et al , 2006Lebedev et al , 2007Giordano et al 2007;Anovitz et al 2009Anovitz et al , 2011Anovitz et al , 2013aAnovitz et al ,b, 2014Anovitz et al , 2015aFavvas et al 2009;Jin et al 2011Jin et al , 2013Clarkson et al 2012a…”

Small-Angle Scattering from Confined and Interfacial Fluids

“…Slope values between À3 and À4 indicate a surface fractal geometry of the coal matrix-pore interface. Reprinted with permission from [84]. Copyright 2009 American Chemical Society deformation of the porous solids remains one of the long-term problems in adsorption science [87].…”

Supercritical Fluids in Confined Geometries

“…SANS and USANS measurements of the structure of two Australian bituminous coals before, during, and after exposure to 155 bar of helium were made to identify any possible effects of pressure alone on the pore size distribution and any irreversible effects upon exposure to high pressures of helium in [84]. Coal 1 (a highly porous, inertinite-rich coal) and coal 2 (a low porosity, vitrinite-rich coal) were selected because of their extremely different porosities.…”