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Title: DIPPER project 871 determination of ideal-gas enthalpies of formation for key compounds, The 1991 project results

Technical Report ·
DOI:https://doi.org/10.2172/10107077· OSTI ID:10107077

Results of a study aimed at improving group-contribution methodology for estimating thermodynamic properties of organic substances are reported. Specific weaknesses where particular group-contribution terms were unknown, or estimated because of lack of experimental data, are addressed by experimental studies of enthalpies of combustion in condensed phase, vapor-pressure measurements, and differential scanning calorimetric (d.s.c.) heat-capacity measurements. Ideal-gas enthalpies of formation of cyclohexene, phthalan (2,5-dihydrobenzo-3,4-furan), isoxazole, n-octylamine, di-n-octylamine, tri-n-octylamine, phenyl isocyanate, and 1,4,5,6-tetrahydropyrimidine are reported. Two-phase (liquid + vapor) heat capacities were determined for phthalan, isoxazole, the three octylamines, and phenyl isocyanate. Liquid-phase densities along the saturation line were measured for phthalan and isoxazole at 298 to 425 K. The critical temperature and critical density of n-octylamine were determined from d.s.c. results and critical pressure derived from the fitting procedures. Fitting procedures were used to derive critical temperatures, pressures, and densities for cyclohexene (pressure and density only), phthalan, isoxazole, di-n-octylamine, and phenyl isocyanate. Group-additivity parameters or ring-correction terms are derived.

Research Organization:
National Inst. for Petroleum and Energy Research, Bartlesville, OK (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
FC22-83FE60149
OSTI ID:
10107077
Report Number(s):
NIPER-716; ON: DE94003850; BR: 35AA15000/35AA20000
Resource Relation:
Other Information: PBD: Sep 1993
Country of Publication:
United States
Language:
English