Abstract
Coalbed Methane is an attractive source of energy to mitigate the
growing energy demand of India. It is often abbreviated as
unconventional source of energy. In this paper two bore hole samples
(J/01 & J/02) were collected and characterized for the isotherm studies
to know the sorption capacity of the coal. Pure gas isotherm was
constructed based on the manomateric method. Pure gas isotherm was
constructed in indigenously fabricated setup. Langmuir model was used
for the prediction of sorption capacity at particular pressure. Langmuir
constants (PL & VL) were calculated using regression analysis. It was
found that volume wise CO2 has 2.09 to 2.75 times more adsorption
capacity than coal.Once pure gas isotherm was drawn and PL and VL was
calculated. Langmuir constants were given as follows: CH4 -VL (scf/ton)
of J/01 and J/02 are 227.27 and 454.55 respectively CH4 -PL (psi) of
J/01 and J/02 are 128.54 and 173.68 CO2-VL (scf/ton) of J/01 and J/02
are 476.19 1250 respectively CO2-PL(psi) of J/01 and J/02 are 133.33
596.13 Binary mixture of CH4 and CO2 was modelled at different gas
mixtures and at pressure of 2000 psi. Multicomponent iterative model
(MIA) was proposed using Newton Raphson iteration to study the co
adsorption isotherm of CH4 and CO2 at different binary mixtures. It was
found that one CO2 mole fraction increases in gas phase. For sample J/01
Enhanced Coalbed Methane (ECBM) recovery will occur after 27.4 % of CO2
in gas phase while ECBM recovery will occur after 13.03% of CO2 in gas
phase. Pure component isotherm and co adsorption isotherm is given in
figure 1 & 2.