Adsorption Isotherms of Coals and Shales

  • Determining gas storage capacity by adsorption at reservoir temperature and pressure
  • Single or composite samples
  • Equilibrium moisture basis is standard but other moisture bases can be used as required
  • Range of gases include methane (CH4), ethane (C2H6), propane (C3H8), carbon dioxide (CO2) and nitrogen (N2)
  • Absolute or excess (Gibbs) adsorption can be determined
  • Gas saturation and critical desorption pressure can be calculated on request
    Modelling using Langmuir is standard and gives the Langmuir Pressure (PL) and Langmuir Volume (VL)
  • Other adsorption models such as the BET multilayer model and the pore filling models of Dubinin-Astakhov (D-A) and Dubinin-Radushkevich (D-R) can also be provided
  • Extended Langmuir modelling is used to determine the adsorption isotherm for the gas mixtures. Single gas adsorption isotherms are first determined then the extended Langmuir model is applied to these end members. Two or more gases can be modelled for the same reservoir.
  • Moisture content and ash yield are always carried out in conjunction with adsorption isotherm analysis.
  • Reports are provided as pdf files and as spreadsheets