Affiliation:
1. School of Mathematical and Physical Sciences, University of New England , Biddeford, Maine 04005, USA
Abstract
Pressure–composition binary phase diagrams were determined for methanethiol, dimethyl sulfide, thiophene, benzothiophene, or dibenzothiophene with carbon dioxide at temperatures from 363 to 453 K and pressures from 2 to 20 MPa. Utilizing Gibbs ensemble Monte Carlo molecular simulation, phase coexistence compositions were determined, along with the impact of 4% water cosolvent on select results. Solution structure as a function of pressure and temperature is characterized via radial distribution functions. Comparison to available experimental composition data gives overall mean absolute percentage deviations of 2.2% for thiophene, 37% for methanethiol, and 99% for benzothiophene. Solubilities in a CO2-rich phase are calculated to be sufficient to allow extraction and detection of the compounds studied here via supercritical fluid chromatography and mass spectrometry as a possible analysis approach for future Mars rover missions.