Journal
ENERGY & FUELS
Volume 35, Issue 16, Pages 13109-13123Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acs.energyfuels.1c01693
Keywords
-
Categories
Funding
- DOE Office of Science [DE-AC02-06CH11357]
Ask authors/readers for more resources
Hierarchical gas confinement in porous coal material plays a critical role in gas adsorption and storage in underground coal seams. Small-angle neutron scattering (SANS) with contrast-matching method was used to quantify gas confinement in macro-/meso-/micropores on high-rank anthracite, revealing changes in scattering contrast with pressure variation during gas injection. The study differentiated gas confinement in different pore sizes based on model-free and data-fitting methods, highlighting the importance of considering pore accessibility and scattering background when estimating scattering contrast in micropores.
Hierarchical gas confinement in porous coal material is critical for gas adsorption and storage in underground coal seams. Small-angle neutron scattering (SANS) with contrast-matching method has been employed to quantify the possible gas confinement in macro-/meso-/micropores on high-rank anthracite with the forms of powder and thin sections. Model-free and data-fitting methods were used to estimate the hierarchical scattering contrast, the absolute difference between the scattering length densities (SLDs) of the solid matrix and fluid in pores, under different pressure and gas injection conditions. The scattering contrast generally reduces in macro-/mesopores but increases in micropores as the pressure increases during CD4 injection, suggesting a high degree of densification of methane in micropores. However, the cases for CO2 injection are complex, which could be because of multiple factors, including matrix compression and sorption-induced swelling, pore accessibility, the structure of the confined fluid, and the local structure of the matrix. This study uniquely differentiates the gas confinement in macro-/meso-/micropores of high-rank coal based on the model-free method considering pore accessibility effect and data-fitting method with and without considering effects of polydispersity and background. Care should be made to estimate scattering background, which influences estimating the scattering contrast in micropores based on the data-fitting method.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available