The desorption process is observed as CO2 degassing out of the coal. After flooding the coal with CO2 up to 1600 psi, the sub-bituminous coal sample is removed from the pressure chamber and exposed to atmospheric conditions. The CO2 desorption occurs mostly through the cleats and fractures in the coal (highlighted with white marker), evidenced by the stream of bubbles of the soapy water. Also, tiny bubbles burst randomly in the coal bulk matrix, indicating the location of microfractures conducting the CO2. Details of the research in: Vega-Ortiz, Carlos . 2021. Optimization of CO2 Mass Transport and Storage at In-situ Conditions in Two Unconventional Plays: Coalbed Methane and Carbonaceous Mudstones. Ph.D. Thesis. The University of Utah.