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Hydrodenitrogenation: An increasingly important part of catalytic hydroprocessing interlocking of thermodynamics and kinetics

Description: This report outlines a new use of thermodynamic property data. The Gibbs energies of reaction obtained from thermodynamic property measurements are used to estimate, with some success, relative reactivities for aromatic organonitrogen compounds. Calculated relative rates of reaction reproduce literature values within one power of ten. The relative rates of reaction are shown to be directly proportional to the concentration of hydrogenated species formed during hydrodenitrogenation (HDN). The production of completely saturated ring systems (overhydrogenation) in HDN reactions using conventional hydroprocessing is explained solely in terms of the thermodynamics in operation in the system. The results obtained show that the order of relative reactivity obtained is strongly dependence can account for some apparent contradictions when kinetic studies reported in the literature are compared. The results for a study of the hydroprocessing of a straight-run gas oil are reproduced in this report. The formation of anilines and the increase in indole concentration above that in the original gas oil sample are explained via the thermodynamics operating in the system.
Date: April 1, 1992
Creator: Steele, W.V. & Chirico, R.D.
Partner: UNT Libraries Government Documents Department

Thermodynamics of the hydrodenitrogenation of carbazole

Description: A thermodynamic analysis, based on accurate experimental Gibbs energies of formation, was completed for the key hydrogen-consuming steps in the HDN reaction network for carbazole. The results were compared with literature reaction studies. The concept of crossover temperature'' is shown to be a valuable tool in the interpretation of literature reaction-study results. Methods of nitrogen removal from aromatic materials are discussed in light of the findings of the thermodynamic analysis. It is concluded that the removal of nitrogen from heterocyclic aromatic nitrogen-containing compounds with conventional hydrodesulfurization catalysts, temperatures, and hydrogen pressures occurs under thermodynamic control'' with unavoidably high hydrogen consumption. The report also concludes that to reduce hydrogen consumption in the HDN of carbazole, pathways via 1,2,3,4a,9a-hexahydrocarbazole must be followed. Conditions under which these processes are possible are discussed. 36 refs., 9 figs.
Date: October 1, 1991
Creator: Steele, W.V. & Chirico, R.D.
Partner: UNT Libraries Government Documents Department

The thermodynamic properties of 2-aminobiphenyl (an intermediate in the carbazole/hydrogen reaction network)

Description: Catalytic hydrodenitrogenation (HDN) is a key step in upgrading processes for conversion of heavy petroleum, shale oil, tar sands, and the products of the liquefaction of coal to economically viable products. This research program provides accurate experimental thermochemical and thermophysical properties for key organic nitrogen-containing compounds present in the range of alternative feedstocks, and applies the experimental information to thermodynamic analyses of key HDN reaction networks. This report is the first in a series that will lead to an analysis of a three-ring HDN system; the carbazole/hydrogen reaction network. 2-Aminobiphenyl is the initial intermediate in the HDN pathway for carbazole, which consumes the least hydrogen possible. Measurements leading to the calculation of the ideal-gas thermodynamic properties for 2-aminobiphenyl are reported. Experimental methods included combustion calorimetry, adiabatic heat-capacity calorimetry, comparative ebulliometry, inclined-piston gauge manometry, and differential-scanning calorimetry (d.s.c). Entropies, enthalpies, and Gibbs energies of formation were derived for the ideal gas for selected temperatures between 298.15 K and 820 K. The critical temperature and critical density were determined for 2-aminobiphenyl with the d.s.c., and the critical pressure was derived. The Gibbs energies of formation are used in thermodynamic calculations to compare the feasibility of the initial hydrogenolysis step in the carbazole/H{sub 2} network with that of its hydrocarbon and oxygen-containing analogous; i.e., fluorene/H{sub 2} and dibenzofuran/H{sub 2}. Results of the thermodynamic calculations are compared with those of batch-reaction studies reported in the literature. 57 refs., 8 figs., 18 tabs.
Date: December 1, 1990
Creator: Steele, W.V.; Chirico, R.D.; Knipmeyer, S.E. & Nguyen, A.
Partner: UNT Libraries Government Documents Department

The thermodynamic properties of 2,3-benzothiophene

Description: Upgrading of heavy fossil fuels is normally done by hydrotreating in the presence of catalysts at 5 to 15 MPa pressure of hydrogen and 575 to 700 K. The efficient use of expensive hydrogen in this process is essential to the economic viability of alternative fuel sources (heavy petroleum, tar sands, shale oil, and the products of the liquefaction of coal). 2,3-Benzothiophene is widely used as a model compound in catalyst-comparison and kinetic studies of the hydrodesulfurization (HDS) mechanism. To perform a thermodynamic analysis of the 2,3-benzothiophene/hydrogen reaction network at the process temperatures, Gibbs energies of reaction at those high temperatures are required for the molecules involved. Measurements leading to the calculation of the ideal-gas thermodynamic properties for 2,3-benzothiophene are reported. Experimental methods included adiabatic heat-capacity calorimetry, comparative ebulliometry, inclined-piston gauge manometry, and differential-scanning calorimetry (d.s.c.). The critical temperature and critical density were determined with the d.s.c., and the critical pressure was derived. Entropies, enthalpies, and Gibbs energies of formation were derived for the ideal gas for selected temperatures between 260 K and 750 K. These values were derived by combining the reported measurements with values published previously for the enthalpy of combustion, the enthalpy of fusion, and the absolute entropy and enthalpy of the liquid at the triple-point temperature. Measured and derived quantities were compared with available literature values. 55 refs., 6 figs., 13 tabs.
Date: January 1, 1991
Creator: Chirico, R.D.; Knipmeyer, S.E.; Nguyen, A. & Steele, W.V.
Partner: UNT Libraries Government Documents Department

The thermodynamic properties of 2-methylaniline and trans-(R,S)- decahydroquinoline

Description: Measurements leading to the calculation of the ideal-gas thermodynamic properties for 2-methylaniline and trans-(R,S)-decahydroquinoline are reported. Experimental methods included combustion calorimetry, adiabatic heat-capacity calorimetry, comparative ebulliometry, inclined-piston gauge manometry, and differential-scanning calorimetry (dsc). Entropies, enthalpies, and Gibbs energies of formation were derived for the ideal gas at selected temperatures for both compounds. Critical properties were determined for 2-methylaniline with the dsc. Measured combustion enthalpies, vapor pressures, critical properties, and ideal-gas entropies were compared with estimated and experimental literature values. 59 refs., 7 figs., 15 tabs.
Date: February 1, 1990
Creator: Steele, W.V.; Chirico, R.D.; Nguyen, A. & Knipmeyer, S.E.
Partner: UNT Libraries Government Documents Department

Thermodynamic properties of 9-methylcarbazole and 1,2,3,4-tetrahydro-9-methylcarbazole

Description: Removal of carbazole and its derivatives from heavy petroleum has proved to be particularly difficult using present technology. Studies have shown carbazole and its alkyl-homologs are the dominant nitrogen-containing components in clarified slurry oils, thereby indicating their low reactivity and/or formation during cat-cracking processes. The results reported here will point the way to the development of new methods of nitrogen removal from carbazole and its derivatives. Measurements leading to the calculation of the ideal-gas thermodynamic properties are reported for 9-methylcarbazole and 1,2,3,4-tetrahydro-9-methylcarbazole. For studies on 1,2,3,4-tetrahydro-9-methylcarbazole experimental methods included combustion calorimetry, adiabatic heat-capacity calorimetry, vibrating-tube densitometry, comparative ebulliometry, inclined-piston gauge manometry, and differential-scanning calorimetry (d.s.c.). Adiabatic heat-capacity and combustion calorimetric studies were reported previously for 9-methylcarbazole. Vapor pressures by comparative ebulliometry and inclined-piston gauge manometry, and heat-capacities for the liquid phase by d.s.c. are reported here. Entropies, enthalpies, and Gibbs energies of formation were derived for the ideal gas for both compounds for selected temperatures between 298.15 K and near 700 K. The Gibbs energies of formation will be used in a subsequent report in thermodynamic calculations to study the reaction pathway of the initial hydrogenation step in the carbazole/H{sub 2} hydrodenitrogenation network. 52 refs., 9 figs., 15 tabs.
Date: April 1, 1991
Creator: Steele, W.V.; Knipmeyer, S.E.; Nguyen, A. & Chirico, R.D.
Partner: UNT Libraries Government Documents Department

The thermodynamic properties of benzothiazole and benzoxazole

Description: 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.
Date: August 1, 1991
Creator: Steele, W.V.; Chirico, R.D.; Knipmeyer, S.E. & Nguyen, A.
Partner: UNT Libraries Government Documents Department

Thermodynamic properties for polycyclic systems by non-calorimetric methods

Description: A detailed vibrational spectroscopic study of furan, pyrrole, and thiophene has been completed. These compounds form part of the base of five-membered ring systems on which the rest of the research program will be built Several methyl-substituted derivatives were also studied. The results will be used to confirm the model for alkyl- substitution in the ring systems. Gas-phase spectra and fundamental- frequency assignments were completed for 2,3- and 2,5-dihydrofuran. Those compounds initiate work on ring-puckering within the research program. A paper describing the need for third virial estimation, when using the virial equation of state to derive thermodynamic properties at pressures greater than 1 bar was completed.
Date: March 1, 1993
Creator: Steele, W.V.; Chirico, R.D. & Klots, T.D.
Partner: UNT Libraries Government Documents Department

The thermodynamic properties of thianthrene and phenoxathiin

Description: Measurements leading to the calculation of the ideal-gas thermodynamic properties are reported for thianthrene (Chemical Abstracts registry number [92-85-3]) and phenoxathiin (registry number [262-20-41]). Experimental methods included combustion calorimetry, adiabatic heat-capacity calorimetry, vibrating-tube densitometry, comparative ebulliometry, inclined-piston gauge manometry, and differential-scanning calorimetry (d.s.c.). Critical properties were estimated for both materials based on the measurement results. Entropies, enthalpies, and Gibbs energies of formation were derived for the ideal gas for both compounds for selected temperatures between 298.15 K and 700 K. The property-measurement results reported here for thianthrene and phenoxathiin provide the first experimental gas-phase Gibbs energies of formation for tricyclic diheteroatom-containing molecules.
Date: April 1, 1993
Creator: Steele, W.V.; Chirico, R.D.; Knipmeyer, S.E. & Nguyen, A.
Partner: UNT Libraries Government Documents Department

Gas Hydrate Research Database and Web Dissemination Channel

Description: To facilitate advances in application of technologies pertaining to gas hydrates, a United States database containing experimentally-derived information about those materials was developed. The Clathrate Hydrate Physical Property Database (NIST Standard Reference Database {number_sign} 156) was developed by the TRC Group at NIST in Boulder, Colorado paralleling a highly-successful database of thermodynamic properties of molecular pure compounds and their mixtures and in association with an international effort on the part of CODATA to aid in international data sharing. Development and population of this database relied on the development of three components of information-processing infrastructure: (1) guided data capture (GDC) software designed to convert data and metadata into a well-organized, electronic format, (2) a relational data storage facility to accommodate all types of numerical and metadata within the scope of the project, and (3) a gas hydrate markup language (GHML) developed to standardize data communications between 'data producers' and 'data users'. Having developed the appropriate data storage and communication technologies, a web-based interface for both the new Clathrate Hydrate Physical Property Database, as well as Scientific Results from the Mallik 2002 Gas Hydrate Production Research Well Program was developed and deployed at http://gashydrates.nist.gov.
Date: September 30, 2009
Creator: Frenkel, Micheal; Kroenlein, Kenneth; Diky, V; Chirico, R.D.; Kazakow, A.; Muzny, C.D. et al.
Partner: UNT Libraries Government Documents Department

Thermodynamic properties by non-calorimetric methods. Progress report, August 1, 1988--July 31, 1989

Description: This three year research program provides a valuable complement to the experimental programs currently in progress at NIPER for the Advanced Research and Technology Development (AR and TD) and Advanced Exploration and Process Technology (AEPT) divisions of the Department of Energy. These experimental programs are focused on the calorimetric determination of thermodynamic properties of key polynuclear heteroatom-containing aromatic molecules. This project for the Office of Energy Research focuses on the non-calorimetric determination of thermodynamic properties through the extension of existing correlation methodologies and through molecular spectroscopy with statistical mechanics. The paper discusses progress in three areas: (1) Improvement of thermochemical and thermophysical property predictions via enhancement of group-contribution methods using two approaches, namely, development and improvement of group-contribution parameters via correlations involving the expanded modern thermodynamics data base and development of group-contribution parameters via molecular spectroscopy and statistical mechanics of key monocyclic organic compounds; (2) Molecular spectroscopy and statistical mechanics: equipment development and developments in interpretation and assignment of spectra; and (3) Thermophysical property correlations.
Date: December 31, 1989
Creator: Steele, W.V.; Chirico, R.D.; Collier, W.B. & Strube, M.M.
Partner: UNT Libraries Government Documents Department

Determination of ideal-gas enthalpies of formation for key compounds:

Description: The results of a study aimed at improvement of group-contribution methodology for estimation of thermodynamic properties of organic and organosilicon 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 the condensed phase, vapor-pressure measurements, and differential scanning calorimetric (d.s.c.) heat-capacity measurements. Ideal-gas enthalpies of formation of ({plus minus})-butan-2-ol, tetradecan-1-ol, hexan-1,6-diol, methacrylamide, benzoyl formic acid, naphthalene-2,6-dicarboxylic acid dimethyl ester, and tetraethylsilane are reported. A crystalline-phase enthalpy of formation at 298.15 K was determined for naphthalene-2,6-dicarboxylic acid, which decomposed at 695 K before melting. The combustion calorimetry of tetraethylsilane used the proven fluorine-additivity methodology. Critical temperature and critical density were determined for tetraethylsilane with differential scanning calorimeter and the critical pressure was derived. Group-additivity parameters useful in the application of group- contribution correlations are derived. 112 refs., 13 figs., 19 tabs.
Date: October 1, 1991
Creator: Steele, W.V.; Chirico, R.D.; Nguyen, A.; Hossenlopp, I.A. & Smith, N.K.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Date: September 1, 1993
Creator: Steele, W. V.; Chirico, R. D.; Knipmeyer, S. E.; Nguyen, A. & Tasker, I. R.
Partner: UNT Libraries Government Documents Department

The thermodynamic properties of 4,5,9,10-tetrahydropyrene and 1,2,3,6,7,8-hexahydropyrene

Description: Measurements leading to the calculation of the ideal-gas thermodynamic properties are reported for 4,5,9,10-tetrahydropyrene and 1,2,3,6,7,8-hexahydropyrene. Experimental methods included combustion calorimetry, adiabatic heat-capacity calorimetry, vibrating-tube densitometry, comparative ebulliometry, inclined-piston gauge manometry, and differential-scanning calorimetry (d.s.c.). Critical properties were estimated for both materials based on the measurement results. Entropies, enthalpies, and Gibbs energies of formation were derived for the ideal gases for selected temperatures between 380 K and 700 K. The property-measurement results reported here for 4,5,9,10-tetrahydropyrene and 1,2,3,6,7,8-hexahydropyrene are the first for these important intermediates in the pyrene/H{sub 2} hydrogenation reaction network.
Date: December 1, 1992
Creator: Chirico, R. D.; Knipmeyer, S. E.; Nguyen, A.; Smith, N. K. & Steele, W. V.
Partner: UNT Libraries Government Documents Department

Thermodynamic properties by non-calorimetric methods. Final report

Description: This research program provided a valuable complement to the experimental programs currently in progress at NIPER for the Advanced Research and Technology Development (AR and TD) and Advanced Exploration and Process Technology (AEPT) divisions of the Department of Energy. These experimental programs are focused on the calorimetric determination of thermodynamic properties of key polynuclear heteroatom-containing aromatic molecules. The project for the Office of Energy Research focused on the non-calorimetric determination of thermodynamic properties through the extension of existing correlation methodologies and through molecular spectroscopy with statistical mechanics. The paper discusses the following studies: Group-contribution approach for polycyclic aromatic hydrocarbons (naphthalene, phenanthrene, anthracene, pyrene, 3-methylphenanthrene, benzoquinolines, biphenyl/hydrogen system); Group-contribution approach for key monocyclic organic compounds; Molecular spectroscopy and statistical mechanics; and Thermophysical property correlations.
Date: December 31, 1992
Creator: Steele, W.V.; Chirico, R.D.; Collier, W.B.; Strube, M.M. & Klots, T.D.
Partner: UNT Libraries Government Documents Department