Prediction Model for Isothermal Adsorption Curves Based on Adsorption Potential Theory and Adsorption Behaviors of Methane on Granular Coal

In this study, adsorption tests of methane on granular coal were performed to investigate the effects of various factors (temperature, particle size, pressure, and water content) on the adsorption behaviors. Using the experimental results, a new model was built for predicting isothermal adsorption curves by optimizing the saturated vapor pressure parameter in the adsorption potential theory. The predicted isothermal adsorption curves indicate that different coal samples have different saturated vapor pressure parameters. The fitting accuracy of different vapor pressure parameters was determined, for which the functions were also established. Thus, the optimal vapor pressure parameters for coal samples with different particle sizes were obtained and used to build a prediction model for the isothermal adsorption curves. To verify the accuracy, the model was used to predict the isothermal adsorption curve under the temperature of 308 K. The results were then compared with the experimental values measured at the corresponding temperature. Good agreement was found, thus verifying the veracity and accuracy of the model. Hence, the results of this study may provide a new method to predict the isothermal adsorption curves of coal at different temperatures.