Study on coal-bed methane isothermal adsorption at different temperatures based on the monolayer adsorption theory

摘要

Adsorption volume is not only an important parameter to evaluate the porous characteristics of coal, but can also provide basic data for adsorption capacity calculation. The apparent and true adsorption volumes were introduced and the calculation of adsorption volume was modified. The differences between apparent and true adsorption volumes were compared and analyzed. The fitted formula between adsorption constant and temperature was established in this work. The results indicated that: the differences between apparent and true adsorption volumes become much more significant with the rising temperature. The adsorption ability of coal is in close relationship with specific surface, and the Langmuir constant a presents a slow growth due to the increase in specific surface area when the temperature was raised. Such research results not only can help understand the adsorption properties of coal mass, but also can provide appropriate guidance in exploitation of Coal-Bed Methane (CBM).