Excess molar enthalpies for (propane+ethene) over the temperature range from 273.15 K to 373.15 K and the pressure range from 5 MPa to 15 MPa

✍ Scribed by P.R. Brown; J.B. Ott; L.R. Lemon; J.D. Moore

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 498 KB
• Volume: 28
• Category: Article
• ISSN: 0021-9614
• DOI: 10.1006/jcht.1996.0080

✦ Synopsis

Thus, measurements have been made at a temperature where both components are liquid (T = 273.15 K), at four temperatures where one component (C3H8) is a liquid while the other (C2H4) is a supercritical fluid T = (298.15, 323.15, 348.15, and 363.15) K, a temperature (T = 369.82 K) at or very near the critical temperature of propane and well above the critical temperature of ethene, and at one temperature where both components are supercritical fluids (T = 373.15 K). At T = 273.15 K and p = 5 MPa, the minimum H E m is -220 J•mol -1 , with the composition corresponding to the minimum skewed towards the ethene-rich mixture. With increasing pressure, H E m becomes less negative, and the minimum changes to a maximum, whose composition switches towards the propane-rich mixture. The result is an s-shaped H E m (x) curve at intermediate pressures and a positive H E m (x) curve at the high pressures. At the higher temperatures, where supercritical fluids are present, the maximum and minimum values of H E m are much larger, and both temperature and pressure have a large effect on H E m . Thus H E m changes from a minimum value of approximately -2400 J•mol -1 with a positive pressure coefficient (1H E