The Experts below are selected from a list of 159 Experts worldwide ranked by ideXlab platform
Z. Mcmahon - One of the best experts on this subject based on the ideXlab platform.
-
Experimental determination of acetylene and ethylene solubility in Liquid Methane and ethane: Implications to Titan’s surface
Geochimica et Cosmochimica Acta, 2017Co-Authors: S. Singh, J. Ph. Combe, D. Cordier, A. Wagner, Vincent Chevrier, Z. McmahonAbstract:Abstract In this study, the solubility of acetylene (or ethyne, C2H2) and ethylene (or ethene, C2H4) in Liquid Methane (CH4) and ethane (C2H6) has been experimentally determined at Titan surface temperature (90 K) and pressure (1.5 bars). As predicted by theoretical models, the solubilities of acetylene and ethylene are very large at Titan temperature and these species are most likely to be abundantly present in the lakes and as evaporites on the shores or dry lake beds. Our results indicate the solubility of 4.9 × 10−2 mole fraction for acetylene in Methane and 48 × 10−2 mole fraction in ethane; for ethylene, 5.6 × 10−1 mole fraction in Methane and 4.8 × 10−1 mole fraction in ethane. Assuming the mole fractions from atmospheric models in the lower stratosphere and equilibrium with the surface, we determined that the lakes on Titan that cover ∼400,000 km2 are not saturated. The Liquid lakes on Titan act as an important reservoir for both acetylene and ethylene. Assuming difference of Methane and ethane content in the lakes at different latitudes, the difference in solubility in Liquid Methane and ethane, solutes in lakes may change with the temporal evolution (such as; evaporation and condensation) over seasons and geological time scales.
Jacob Leachman - One of the best experts on this subject based on the ideXlab platform.
-
Experimental PρT-x measurements of Liquid Methane-ethane-nitrogen mixtures
Fluid Phase Equilibria, 2018Co-Authors: Ian A. Richardson, J.w. Hartwig, Jacob LeachmanAbstract:Abstract NASA is designing an unmanned submarine to explore the hydrocarbon rich seas of Saturn's moon Titan. Titan is the only known celestial body in our solar system other than Earth with stable Liquid seas on its surface. The thermodynamic properties of Titan's seas have not been well characterized. This work investigates the solubility of nitrogen in varying Liquid Methane-ethane compositions and the effects of dissolved nitrogen on the density of the sea. Twenty-one pressure-density-temperature-composition (PρT-x) measurements are presented from 92 K to 96 K for pressures from 1 bar to 11 bar for varying compositions of Methane, ethane, and nitrogen. These measurements are being used to aid in thermodynamic modeling of the Titan seas as well as the design of the Titan Submarine.
C. Mckinley - One of the best experts on this subject based on the ideXlab platform.
-
Solubility of Solid Benzene, Toluene, n-Hexane, and n-Heptane in Liquid Methane
Advances in Cryogenic Engineering, 1995Co-Authors: G. P. Kuebler, C. MckinleyAbstract:Reliable phase equilibrium data are essential for the design of effective and economical gas treatment processes such as natural gas liquefaction. Data on cryogenic mixtures involving relatively simple molecules are also of theoretical interest. An apparatus and the techniques developed to obtain solid–Liquid phase equilibrium data for cryogenic systems are described here. Results are presented for the individual solubilities of solid benzene, toluene, n-hexane, and n-heptane in Liquid Methane.
D. Serazio - One of the best experts on this subject based on the ideXlab platform.
-
Speed of sound measurements in Liquid Methane (CH4) at cryogenic temperatures between (130 and 162) K and at pressures up to 10 MPa
The Journal of Chemical Thermodynamics, 2020Co-Authors: G. Cavuoto, S. Lago, P.a. Giuliano Albo, D. SerazioAbstract:Abstract This paper reports speed of sound experimental measurements in Liquid Methane ( CH 4 ) along five isotherms, in the temperature range of (130 and 162) K, and for pressures up to 10 MPa. A dedicated experimental apparatus, custom-designed for accurate speed of sound measurement at cryogenic temperatures and high pressures, has been developed and the double pulse-echo technique has been adopted. In order to characterize this new apparatus and its performance, experimental results have been compared with speed of sound values of Liquid Methane available in literature. A further comparison has been made between the experimental measurements and the speed of sound values obtained using the reference equation of state of Methane of Setzmann and Wagner, as well as the GERG-2008 model. The ultrasonic path-length has been calibrated using pure water as a reference fluid, with a relative uncertainty of 0.026%. The temperature was measured with two platinum resistance thermometers with an absolute uncertainty of 0.02 K. Thermometers have been calibrated using the ITS-90 temperature scale between the triple point of argon and the triple point of water. Finally, the relative expanded uncertainty (k = 2) associated to the obtained results is of 0.4%, mainly influenced by the repeatability of the measurements.
Christopher P. Mckay - One of the best experts on this subject based on the ideXlab platform.
-
Titan under a red dwarf star and as a rogue planet: requirements for Liquid Methane
Planetary and Space Science, 2011Co-Authors: Ashley E. Gilliam, Christopher P. MckayAbstract:Abstract Titan has a surface temperature of 94 K and a surface pressure of 1.4 atmospheres. These conditions make it possible for Liquid Methane solutions to be present on the surface. Here, we consider how Titan could have Liquid Methane while orbiting around an M4 red dwarf star, and a special case of Titan orbiting the red dwarf star Gliese 581. Because light from a red dwarf star has a higher fraction of infrared than the Sun, more of the starlight will reach the surface of Titan because its atmospheric haze is more transparent to infrared wavelengths. If Titan was placed at a distance from a red dwarf star such that it received the same average flux as it receives from the Sun, we calculate the increased infrared fraction, which will warm surface temperatures by an additional ∼10 K. Compared to the Sun, red dwarf stars have less blackbody ultraviolet light but can have more Lyman α and particle radiation associated with flares. Thus depending on the details, the haze production may be much higher or much lower than for the current Titan. With the haze reduced by a factor of 100, Titan would have a surface temperature of 94 K at a distance of 0.23 AU from an M4 star and at a distance of 1.66 AU, for Gliese 581. If the haze is increased by a factor of 100 the distances become 0.08 and 0.6 AU for the M4-star and Gliese 581, respectively. As a rogue planet, with no incident stellar flux, Titan would need 1.6 W/m 2 of geothermal heat to maintain its current surface temperature, or an atmospheric opacity of 20× its present amount with 0.1 W/m 2 of geothermal heat. Thus Titan-like worlds beyond our solar system may provide environment supporting surface Liquid Methane.
-
Possibilities for methanogenic life in Liquid Methane on the surface of Titan
Icarus, 2005Co-Authors: Christopher P. Mckay, H.d. SmithAbstract:Photochemically produced compounds on Titan, principally acetylene, ethane and organic solids, would release energy when consumed with atmospheric hydrogen, at levels of 334, 57, and 54 kJ mol −1 , respectively. On Earth methanogenic bacteria can survive on this energy level. Here we speculate on the possibility of widespread methanogenic life in Liquid Methane on Titan. Hydrogen may be the best molecule to show the affects of such life because it does not condense at the tropopause and has no sources or sinks in the troposphere. If life is consuming atmospheric hydrogen it will have a measurable effec to n the hydrogen mixing ratio in the troposphere if the biological consumption is greater than 10 8 cm −2 s −1 . Life could develop strategies to overcome the low solubility of organics in Liquid Methane and use catalysts to accelerate biochemical reactions despite the low temperature. The results of the recen t Huygens probe could indicate the presence of such life by anomalous depletions of acetylene and ethane as well as hydrogen at the surface.