A comparison of the influence of adsorbed gases on gas stresses leading to coal and gas outburst

The present work analyzes the influence of seepage and desorption processes on the initial conditions of coal and gas mini-outbursts. A series of laboratory experiments incorporating coal briquettes and three different gases, namely carbon dioxide, methane or nitrogen were carried out. Experiments relied on mini-outburst inducing. Space and time pressure distributions along the briquettes were recorded. A comparative analysis of the results revealed that the observed differences in mini-outbursts initial conditions cannot be explained by means of a simple coal or gas property such as sorption capacity, desorption rate, seepage rate, or viscosity of gas. On the contrary, the efficiency of accumulated gas releasing processes – desorption and diffusion inside of the coal grains and seepage through the briquette coupled processes – seems to explain the observed variations.