Phase behavior of carbon dioxide + 1,2-epoxycyclohexane mixtures

Journal Article · Tue Jul 01 04:00:00 EDT 1997 · Journal of Chemical and Engineering Data

DOI:https://doi.org/10.1021/je960381p· OSTI ID:529761

Super, M S; Enick, R M; Beckman, E J ^[1]

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1. Univ. of Pittsburgh, PA (United States). Dept. of Chemical Engineering

There has been a trend in the chemical industry toward green chemistry and chemical processing. As a result, carbon dioxide has recently received attention as a solvent replacement. The two-phase boundaries of mixtures of carbon dioxide and 1,2-epoxycyclohexane (cyclohexene oxide) were determined at 343 K, 363 K, 383 K, and 405 K for cyclohexene oxide mole fractions of 0.02 < x{sub 2} < 0.65. The bubble/dew points were determined visually in a windowed, variable volume, high-pressure cell during isothermal expansions and compressions of mixtures of known overall composition. Pressure-composition diagrams were constructed from the experimental data, and the critical points of the mixtures were determined for each temperature from these phase diagrams. Although the Peng-Robinson equation of state slightly overestimated the critical pressure, an excellent fit of the remainder of the bubble and dew point data was obtained with a binary interaction parameter of 0.05. Anomalous phase behavior, in the form of remarkably high dew point data, was observed at 383 K and 405 K. {sup 1}H NMR results of the cyclohexene oxide from these experiments suggest that this was due to the formation of poly(cyclohexene ether). The formation of this polymer may have been catalyzed by trace amounts of water in the system. This polymer has a low solubility in CO{sub 2}; therefore, its presence increased the dew point pressure.

• Sponsoring Organization: USDOE, Washington, DC (United States)
• OSTI ID: 529761
• Journal Information: Journal of Chemical and Engineering Data, Journal Name: Journal of Chemical and Engineering Data Journal Issue: 4 Vol. 42; ISSN 0021-9568; ISSN JCEAAX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
CARBON DIOXIDE
COPOLYMERIZATION
CYCLOALKENES
EPOXIDES
EQUATIONS OF STATE
MATERIAL SUBSTITUTION
PHASE STUDIES
SOLVENTS