The reactivity of tetrahydroquinoline, benzylamine and bibenzyl with supercritical water

Houser, Thomas J.; Tsao, C.C.; Dyla, James E.; Atten, Mary K. Van; McCarville, M. Beth

doi:10.1016/0016-2361(89)90096-3

Cited by 34 publications

(38 citation statements)

References 8 publications

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“…These experimental low N 2 yields during artificial heating of coals cannot explain the strong loss of N org during natural anthracitization. Instead, they indirectly support other experimental evidence for ammonia being the main inorganic nitrogen product from hydrous pyrolysis of kerogen and model compounds (Ader et al, 1998a(Ader et al, , b, 2000, as well as of other nitrogen heterocyles (Houser et al, 1986(Houser et al, , 1989Katritzky et al, 1995Katritzky et al, , 1997Ogunsola, 2000;Yuan et al, 2006).…”

Section: The Role Of H O-containing Hot Fluids During Transformationsupporting

confidence: 67%

Organic nitrogen chemistry during low-grade metamorphism

Boudou

Schimmelmann

Ader

et al. 2008

Geochimica et Cosmochimica Acta

136

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-Most of the organic nitrogen (N org ) on Earth is disseminated in crustal sediments and rocks in the form of fossil nitrogen-containing organic matter. The chemical speciation of fossil N org within the overall molecular structure of organic matter changes with time and heating during burial. Progressive thermal evolution of organic matter involves phases of enhanced elimination of N org and ultimately produces graphite containing only traces of nitrogen. Long-term chemical and thermal instability makes the chemical speciation of N org a valuable tracer to constrain the history of sub-surface metamorphism and to shed light on the subsurface biogeochemical nitrogen cycle and its participating organic and inorganic nitrogen pools. This study documents the evolutionary path of N org speciation, transformation and elimination before and during metamorphism and advocates the use of XRay Photoelectron Spectroscopy (XPS) to monitor changes in N org speciation as a diagnostic tool for organic metamorphism. Our multidisciplinary evidence from XPS, stable isotopes, traditional quantitative coal analyses, and other analytical approaches shows that at the metamorphic onset N org is dominantly present as pyrrolic and pyridinic nitrogen. The relative abundance of nitrogen substituting for carbon in condensed, partially aromatic systems (where N is covalently bonded to three C atoms) increases exponentially with increasing metamorphic grade, at the expense of pyridinic and pyrrolic nitrogen. At the same time, much N org is eliminated without significant nitrogen isotope fractionation. The apparent absence of Rayleigh-type nitrogen isotopic fractionation suggests that direct thermal loss of nitrogen from an organic matrix does not serve as a major pathway for N org elimination. Instead, we propose that hot H, O-containing fluids or some of their components gradually penetrate into the carbonaceous matrix and eliminate N org along a progressing reaction front, without causing nitrogen isotope fractionation in the residual N org in the unreacted core of the carbonaceous matrix. Before the reaction front can reach the core, an increasing part of core N org chemically stabilizes in the form of nitrogen atoms substituting for carbon in condensed, partially aromatic systems forming graphite-like structural domains with delocalized π-electron systems (nitrogen atoms substituting for "graphitic" carbon in natural metamorphic organic matter). Thus, this nitrogen species with a conservative isotopic composition is the dominant form of residual nitrogen at higher metamorphic grade.

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Section: The Role Of H O-containing Hot Fluids During Transformationsupporting

confidence: 67%

Organic nitrogen chemistry during low-grade metamorphism

Boudou

Schimmelmann

Ader

et al. 2008

Geochimica et Cosmochimica Acta

136

View full text Add to dashboard Cite

show abstract

“…Their research program focused on the removal of heteroatoms, especially nitrogen, from model compounds thought to be representative of structures found in coal. Compounds investigated include quinoline and isoquinoline (Houser et al, 1986;Li and Houser, 1992); tetrahydroquinoline, benzylamine and bibenzyl (Houser et al, 1989); benzaldehyde, benzylidenebenzylamine, benzyl alcohol, and benzoic acid (Tsao et al, 1992); and l-chlorohexane, ethyl benzilate, trihexylamine, quinuclidine, phenylpiperidine, and phenylpyridine (Houser et al, 1993). Several of the compounds in this most recent report mimic structures in chemical weapons rather than coal.…”

Section: Aiche Journalmentioning

confidence: 90%

“…The products were also very similar. Houser et al (1989) noted that water was clearly a reactant in benzylamine pyrolysis but not in bibenzyl pyrolysis. They recognized that a C-N bond was the distinguishing feature that facilitated hydrolysis (Tsao et al, 1992).…”

Section: Aiche Journalmentioning

confidence: 96%

Reactions at supercritical conditions: Applications and fundamentals

et al. 1995

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“…Benzaldehyde was an important intermediate in a previous nitrogen removal study (2). Several of the oxygen compounds examined were either observed or postulated as intermediates also.…”

Section: Nitroaen Compoundsmentioning

confidence: 94%

Removal of Heteroatoms from Organic Compounds by Supercritical Water

Houser¹

1992

ACS Symposium Series

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The reactivity of tetrahydroquinoline, benzylamine and bibenzyl with supercritical water

Cited by 34 publications

References 8 publications

Organic nitrogen chemistry during low-grade metamorphism

Organic nitrogen chemistry during low-grade metamorphism

Reactions at supercritical conditions: Applications and fundamentals

Removal of Heteroatoms from Organic Compounds by Supercritical Water

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