Publications

Coalbed methane is methane gas (CH4) adsorbed in coal seams. In Indonesia there are 11 identified high potential CBM reservoirs. However, these large inventions are not supported by more research about Indonesias CBM potential, particularly the methane adsorption capacity in Indonesian coal. This information about methane adsorption capacity is required to estimate the gas content of CBM reservoirs and as input for production process simulations. This research works with two types of Indonesian coal (Barito and Ombilin), three temperature variations (30 °C, 40 °C, 60 °C), and six pressure variations (150 psia, 300 psia, 450 psia, 600 psia, 750 psia, and 900 psia, also, two moisture content variations (dry coal and moisture equilibrium coal) were factored in. Adsorption of Methane into Indonesian coal is carried out according to isothermic Gibbs adsorption, and Ono-Kondo adsorption modeling. This high pressure adsorption model development consists of two parameters in the calculation: the fluid -solid energy parameter (is/k) and the maximum adsorption capacity (C). Adsorption results reveal that the adsorption capacity of Barito coal is 22% more than that of Ombilin coal. The moisture effect of both types of coal change significantly, becoming around 14% less than that of dry coal. Moreover, the effect of pressure is monotonically proportional to the adsorption capacityof both types of coal. Further, the effect of temperature is inversely proportional to this, based on a comparison between30°C and 40°C, it is about 16.1% for dry Barito coal and 12.8% for dry Ombilin coal. In this research, the maximum adsorption capacity occurred at a 30°C temperature, 900 psia, and dry Barito coal, which is 0.3029 mmol/gram of coal. The highest results for the Ono-Kondo modeling development resulted at is/k for dry Barito coal and at a C value of 30 °C. The deviation between Ono-Kondo modeling and the experimental results is about 0.44%. The Ono-Kondo modeling is therefore quite accurate, enabling a prediction oft the CH4 adsorption capacity of Indonesian coal.Keywords : Coalbed Methane (CBM), Methane adsorption capacity, Indonesian coal, Adsorption experiment, Ono-Kondo modelling.