Alternative equation for sorption data interpretation

Gibbs isotherm measurements are used to quantify the properties of coal-gas-water systems in the field of Enhanced Coalbed Methane production. Gibbs isotherms are measured with a volumetric sorption apparatus using a data interpretation equation which relates pressure, temperature and volume measurements to the Gibbs sorption. An alternative, more simple, equation is presented which allows easier sorption calculation and assessment of the influence of uncertainties. An example of the sensitivity of carbon dioxide Gibbs sorption on coal for the most important parameters is shown.