Error analyses in volumetric method for measuring methane and CO2 adsorption on coal

CO2 sequestration in deep coal seams with enhanced coalbed methane recovery (CO2-ECBM) is emerging as a promising option to stabilise CO2 concentration in the atmosphere. Volumetric method for measuring methane and CO2 adsorption on coal can generate the critical information of the coalbed methane recovery and CO2 storage amount of the target coal seams. In this work, the potential sources of error involved in volumetric method including sample mass, volume, temperature, pressure and compressibility factor and their impact on the measured methane and CO2 adsorption amount have been studied using the law of error propagation. Feasible measures to improve the measured precision based on 'fixed volume' method have also been put forward.