High-temperature programmed pyrolysis of Paleozoic source rocks from Northern Germany and adjacent areas and its thermodynamic constraints

Everlien, G.

doi:10.1016/s0146-6380(96)00093-9

Cited by 7 publications

(5 citation statements)

References 34 publications

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“…Combined with the extended EasyRo% model [21], the following correlation has been established (Fig. 8); for examples, when the methane transformation ratios (TR) are 10% (or 0.1), 50% and 90%, the corresponding Easy Ro values are 0.7%, 1.3% and 3.2%, respectively.…”

Section: Late Gas Generation Potential Of Coalmentioning

confidence: 99%

“…Some early studies concluded that the final stage of late gas generation from coal ended with a maturity at around 2.5% (Ro), and after coal reached maturity between 2.5% and 3.0% (Ro), its gas generation potential is very low and becomes negligible [20]. However, many other studies suggested the late gas potential is still significant; for example, Everlien [21] studied the late gas potential of different type OMs, and reported that considerable amounts of methane are still generated from high rank coals and black shales. In his paper, he suggested that the high-temperature micropyrolysis method was a highly suitable tool for determining the complete residual potential of high-maturity sedimentary rocks in metagenesis (>2.0% R max ).…”

mentioning

confidence: 99%

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Coal pyrolysis characteristics by TG–MS and its late gas generation potential

Wang

Huang

et al. 2015

Fuel

129

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Section: Late Gas Generation Potential Of Coalmentioning

confidence: 99%

mentioning

confidence: 99%

Coal pyrolysis characteristics by TG–MS and its late gas generation potential

Wang

Huang

et al. 2015

Fuel

129

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“…Modelling with Optkin or 2D Petromod software, for example, justifies the early pyrolytic elimination of only a minor amount of anthracitic N org , even under high heat flow of up to 80 W/cm 2 from the Carboniferous to present time (Littke et al, 1995), in reality most N org is not eliminated throughout low grade metamorphism (Boudou and Espitalié, 1995). In the laboratory under dry conditions, most Norg can only be decomposed at unnaturally high temperatures (Everlien, 1996). XPS data of solid pyrolysis residues indicate that programmed pyrolysis in the laboratory can reproduce some trends in naturally metamorphosed samples (Fig.…”

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

confidence: 99%

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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“…R r values from Manang samples range from 4.36 to 5.28 %R r , with an average value of 4.84 %R r . The PDI-1D thermal modeling software of IES, Jü lich (Wygrala, 1988), adopting the extended version of the Easy %R 0 kinetics (Sweeney and Burnham, 1990;Everlien, 1996), was used to estimate the peak paleotemperature. We modelled a pseudo-well, where the Manang samples were close to maximum temperatures for a period of $5 Myr.…”

Section: Vitrinite Reflectance (Vr)mentioning

confidence: 99%

“…Problems arise for the peak paleotemperature estimation for the Marpha area because of the extremely high thermal overprint. Most samples show VR > 6.23 %R r , which is the uppermost limit for the application of the extended version of the Easy %R 0 kinetics (Everlien, 1996). Therefore, neglecting the eventual effect of strain, it can only be presumed that the coalification temperature was above 400°C.…”

Section: Vitrinite Reflectance (Vr)mentioning

confidence: 99%