Acoustic emission generated in systems: coal - carbon dioxide and coal - methane

Authors: Z. Majewska, J. Ziętek

Simultaneous measurements of acoustic emission (AE) and volumetric strain of coal samples subjected to gas sorption - desorption were made.

Carbon dioxide and methane were used as sorbats. The sorption tests were carried out on high - rank coal obtained from Lower Silesia Basin.

Testing facilities used in this study comprised of a pressure vessel and associated pressurization and monitoring systems.

Before testing each coal sample was vacuum degassed. Particulare care was taken to mantain constant conditions during all experiments. Qualitatively different acoustic emission and deformation characteristics were obtained for coal - CO₂ and coal - CH₄ systems.

An attempt has been made to clarify the differences observed in terms of the model of coal structure. This study demonstrates how the interactions between coal matrix and gas molecules can be inferred from remotely measured AE data.