STUDY OF METHANE GAS FLOW CHARACTERISTICS THROUGH POROUS MEDIA AT LABORATORY SCALE

• Main Author: Sola Yessica, Maria
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/85495
• Institution: Institut Teknologi Bandung

Methane gas (CH?) is a more dangerous greenhouse gas than Carbondioxide. Methane emissions are a by-product of underground coal mining. This methane gas can leak and accumulate in confined spaces or in the atmosphere. The quantity and rate of methane emissions depend on the strata and coal seams in the formations above and below that are affected by mining. Therefore, it is necessary to determine the amount of methane emissions from coal seams and overburden with various lithologies and to study the characteristics of permeability and diffusivity. This study aims to determine the characteristics of methane gas flow in various types of rocks (porous media) at the laboratory scale using methane gas sensors and conducted empirical calculations to compare with previous studies. The characteristics of the porous media include values of porosity and intrinsic permeability. Meanwhile, the characteristics of methane gas flow is the diffusion coefficient that covers the gas flux. Analysis shows that porosity and intrinsic permeability are directly proportional to flux and diffusion coefficient. The results show the porosity of sandstone (20%) is greater than siltstone (7%), and their intrinsic permeability values are 5.316 x 10-17 m2 (5.386 x 10-2 mD) and 1.076 x 10- 18 m2 (1.09 x 10-2 mD), and diffusion coefficient of methane gas for sandstone is 1.298 x 10-7 m2/s and siltstone is 1.623 x 10-8 m2/s. It can be concluded that the type of porous media affects the characteristics of methane gas flow. The comparison between the hydraulic conductivity of gas and liquid in sandstone is 3.641 x 10-7 m/s and 10-7.5 m/s and in siltstone 7.37 x 10-8 m/s and 10-11 m/s.