Dissolution of benzene, naphthalene, and biphenyl in a simulated Titan lake

Abstract

We constructed a laboratory apparatus capable of measuring the saturation equilibrium concentration (csat) and dissolution rate constants (keff) of organic solutes in ethane at 94K. We determined a csat of 18.5±1.9mg L−1, 0.159±0.003mg L−1, and 0.039±0.006mg L−1 for benzene, naphthalene, and biphenyl, respectively. The derived csat and keff can be used to predict the dissolution behavior of the materials in ethane under Titan conditions. The aromatic materials dissolved relatively quickly in liquid ethane at 94K, reaching saturation in less than 2h. The dissolution characteristics of benzene in ethane at 94K are compared to those of terrestrial karst-forming materials in water at 298K, and are used to constrain Titan surface processes. We discuss the implications of our measurements on the formation of karst on Titan, the concentration of organics in Titan’s lakes, and the formation of evaporite deposits during lake evaporation.