Browse by author
Lookup NU author(s): Dr Sadegh NadimiORCiD
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
In the process of coal seam fracturing with liquid nitrogen (LN2), the change of coal pore structure has an important influence on the efficiency of coalbed methane (CBM) extraction. The nano-scale pore size distribution (PSD) in coal particles before and after freezing with LN2 are experimentally studied in this work. Coal samples are collected from four coal mines, where coal and gas outburst accidents have occurred. Small angle X-ray scattering technology (SAXS) and scanning electron microscopy (SEM) are used to study the pore structure changes of coal samples quantitatively and qualitatively. It is found that the scattering intensity of coal samples increases after freezing. The PSD of all samples significantly changes in the range of 0.8–7 nm, showing new pore spaces in 0.8–4 nm and fewer pores in the 4–7 nm range. Both the pore fractal dimension and the radius of gyration of coal samples increase after freezing and are mainly affected by the changes in pores and the anisotropy of the coal matrix. Crack expansion and pore connections are observed in the surface structure of the coal sample using SEM. This study provides a better understanding of the nano-scale mechanism of coal seam fracturing with LN2 for the prevention of coal and gas outbursts.
Author(s): Jia P, Jia J, Nadimi S
Publication type: Article
Publication status: Published
Print publication date: 01/11/2023
Online publication date: 11/01/2023
Acceptance date: 18/12/2022
ISSN (print): 1674-2001
ISSN (electronic): 2210-4291
Publisher: Elsevier BV
Altmetrics provided by Altmetric