An Analytical Solubility Model for Nitrogen-Methane-Ethane Ternary Mixtures
Jason Hartwig, Peter Meyerhofer, Ralph Lorenz, Eric Lemmon
Saturn's moon Titan has surface seas of liquid hydrocarbons and a thick, cold, nitrogen atmosphere, and is a target for future exploration. Critical to the design and operation of vehicles for this environment is knowledge of the amount of dissolved nitrogen gas within the cryogenic liquid methane and ethane seas. This paper reviews experimental data on the vapor- liquid equilibrium of nitrogen/methane/ethane mixtures, noting the possibility for split liquid phases, and presents three simple analytical models for conveniently predicting solubility of nitrogen in pure liquid ethane, pure liquid methane, and a mixture of liquid ethane and methane. Model coefficients are fit to three temperature ranges near the critical point, intermediate range, and near the freezing point to permit accurate predictions across the full range of thermodynamic conditions. The models are validated against 2373 points, with mean absolute error between data and model less than 8% for both binary nitrogen/methane and nitrogen/ethane systems, and less than 21% for the ternary nitrogen/methane/ethane system.
, Meyerhofer, P.
, Lorenz, R.
and Lemmon, E.
An Analytical Solubility Model for Nitrogen-Methane-Ethane Ternary Mixtures, J. Phys. & Chem. Ref. Data (JPCRD), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.1016/j.icarus.2017.08.003
(Accessed June 4, 2023)