Study on Adsorption Characteristics of Coal Reservoirs in Yangyi Mine

Abstract

The method for studying the adsorption characteristics of the coal seam has the density method, the mercury-pressing method and the adsorption method. In this experiment, a low temperature nitrogen adsorption method was used to determine the relative data of the coal-like porosity by using the surface area meter TriStarI3020 to determine the arrangement of the nitrogen molecules on the surface of the coal-like samples. Before the beginning of the experiment, the samples of Yang dong coal reservoir were prepared, weighed, the devaporation time was set at 2h, and the temperature was kept at 105℃.The low temperature nitrogen adsorption experiment was carried out by TriStarII3020.The data of adsorption of nitrogen molecules by coal samples at low temperature are obtained by experiments. The gap characteristics of coal samples are studied by analyzing the characteristic folding points and relative relations of the generated linear diagram. Get coal samples under the condition of low temperature changing with pressure adsorption nitrogen molecular data changes, through the analysis of the linear graph of generated features that are characteristic of fold point and relative relationship to study the space characteristics of the coal sample. Through the analysis can determine the area mainly for both ends of the open pores in coal mine, the porosity of the thin neck bottle type, this research has great significance to the adsorption of gas in the coal reservoir, facilitate monitoring during the coal mining operations have an impact on safety production of the gas such as gas. Can get the conclusion: in the low relative pressure p/p°< 0.1 the surface of the coal samples are distributed in nitrogen molecular monolayer, with the increase of pressure surface of coal samples began to multilayer adsorption intensified will appear the characteristics of the molecular cohesion, condensation of a pressure value after the single nitrogen molecules adsorption quantity also presents the geometric growth tend to be infinite.The pore of coal is mainly based on open type and fine neck bottle, and there is a small number of open pores.