The thermodynamic properties of benzothiazole and benzoxazole
This research program, funded by the Department of Energy, Office of Fossil Energy, Advanced Extraction and Process Technology, provides accurate experimental thermochemical and thermophysical properties for key'' organic diheteroatom-containing compounds present in heavy petroleum feedstocks, and applies the experimental information to thermodynamic analyses of key hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation reaction networks. Thermodynamic analyses, based on accurate information, provide insights for the design of cost-effective methods of heteroatom removal. The results reported here, and in a companion report to be completed, will point the way to the development of new methods of heteroatom removal from heavy petroleum. Measurements leading to the calculation of the ideal-gas thermodynamic properties are reported for benzothiazole and benzoxazole. Experimental methods included combustion calorimetry, adiabatic heat-capacity calorimetry, comparative ebulliometry, inclinded-piston gauge manometry, and differential-scanning calorimetry (d.s.c). Critical property estimates are made for both compounds. Entropies, enthalpies, and Gibbs energies of formation were derived for the ideal gas for both compounds for selected temperatures between 280 K and near 650 K. The Gibbs energies of formation will be used in a subsequent report in thermodynamic calculations to study the reaction pathways for the removal of the heteratoms by hydrogenolysis. The results obtained in this research are compared with values present in the literature. The failure of a previous adiabatic heat capacity study to see the phase transition in benzothiazole is noted. Literature vibrational frequency assignments were used to calculate ideal gas entropies in the temperature range reported here for both compounds. Resulting large deviations show the need for a revision of those assignments. 68 refs., 6 figs., 15 tabs.
- Research Organization:
- National Inst. for Petroleum and Energy Research, Bartlesville, OK (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- FC22-83FE60149
- OSTI ID:
- 5364366
- Report Number(s):
- NIPER-533; ON: DE91002250
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
BENZOXAZOLES
THERMODYNAMIC PROPERTIES
PETROLEUM
DENITRIFICATION
THIAZOLES
CALORIMETRY
CRYSTALLIZATION
ENTHALPY
ENTROPY
EVAPORATION
FORMATION FREE ENTHALPY
HYDROGENATION
MEASURING INSTRUMENTS
PHASE TRANSFORMATIONS
PRESSURE MEASUREMENT
SPECIFIC HEAT
TEMPERATURE DEPENDENCE
VAPOR PRESSURE
AZOLES
CHEMICAL REACTIONS
ENERGY
ENERGY SOURCES
FOSSIL FUELS
FREE ENTHALPY
FUELS
HETEROCYCLIC COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXAZOLES
PHYSICAL PROPERTIES
023000* - Petroleum- Properties & Composition
020400 - Petroleum- Processing
400201 - Chemical & Physicochemical Properties