Online determination of natural gas properties
Résumé
Methane number and Lower Heating Value (LHV) of natural gas are determined by the online measurement of thermal conductivity at two different temperatures. Natural gas is first considered as a ternary mixture of the most important components. A pseudo-ternary composition can then be calculated, using the thermal conductivity formula for mixtures derived from kinetic theory. A non-linear system is solved numerically using the Newton-Raphson method. A sensor based on thermal conductivity measurement has been developed and tested successfully for many natural gas compositions.