Characteristic nature of sedimentation and coalification in the Tertiary system of the Japanese Islands

Takahashi, Ryohei; Aihara, Atsuo

doi:10.1016/0166-5162(89)90103-1

Cited by 15 publications

(4 citation statements)

References 6 publications

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“…A simple glance at the data from Table 1 or to Figure 5 shows that the coals used here cover the same range of rank and maceral occurrences as that of the coals selected from the literature. Table 4 also shows the results of the application of the method proposed in this study to estimate the volatile matter content of a large number of coals from SBN Database (104), Penn State Database (796), and Argonne Premium Coals Program (6). Although the Argonne Premium Coals 34 are only a small set compared to those in the databases from coal banks and they are already included in the dataset from Penn State Coal Bank, the fact that they are widely used for a large number of studies led us to consider them separately.…”

Section: Resultsmentioning

confidence: 99%

“…Attempts have been made to relate the variations in the chemical composition of coals brought about by the increase of rank with optical parameters such as vitrinite reflectance. Thus, acceptable correlations were found whenever dealing with homogeneous coals of similar origins and maceral compositions, such as those carried out on German, Canadian, Euro-American, Japanese, Australian, and Indian series of coals. However, when coals of fairly different maceral compositions are used, the correlation between vitrinite reflectance and volatile matter content becomes much poorer, and therefore of little applicability for the estimation of coal rank.…”

Section: Introductionmentioning

confidence: 99%

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Maceral Effects in the Determination of Proximate Volatiles in Coals

et al. 2000

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The proximate and ultimate analyses of coals are commonly regarded as sufficient for a satisfactory description of their chemical composition. This is no doubt true if coal is considered as a whole, but it has to be borne in mind that coals are actually composed of fairly different materials (macerals), and that the corresponding chemical characterization data are average values of the individual compositions of the macerals present in the coal. As regards the determination of coal maturity, the volatile matter content is widely used as a rank parameter, although this characteristic varies not only with coalification but also with maceral composition. A full description of the chemistry of coals, for the prediction of their behavior during industrial processing, requires that the characteristics of their maceral components is also known. This paper is an attempt to evaluate the relative contributions of vitrinite, liptinite, and inertinite to the volatile matter content of coals, over the entire coalification scale. Proximate and petrographic analyses were carried out on 39 coals, and data from 992 more coals and 83 coal fractions were obtained from the literature and coal databases. A best-fit strategy was run with these data, so that the volatile matter contents of the three maceral groups and their variations with rank were determined. The results showed qualitative trends similar to those reported in the literature, but a substantial improvement in their predicting ability was achieved, and the ranges of applicability were expanded to the entire coalification scale.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Maceral Effects in the Determination of Proximate Volatiles in Coals

et al. 2000

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“…Cenozoic coals have the potential to generate oil, since they are relatively rich in hydrogen and aliphatic structures compared with older Carboniferous coals (e.g., Aihara, 1979;Takahashi and Aihara, 1989;MacGregor, 1994;Petersen and Nytoft, 2006;Petersen et al, 2009). The maturity level of hydrocarbon gases in reservoirs generally indicates the maturity level at the time of their expulsion from the source rocks.…”

Section: Evaluation Of the Timing Of Gas Expulsion From Coalmentioning

confidence: 99%

Semi-open and closed system pyrolysis of Paleogene coal for evaluating the timing of hydrocarbon gas expulsion

Takahashi

Suzuki

2017

International Journal of Coal Geology

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Hydrocarbon gas expulsion from coal source rocks takes place under conditions intermediate between an open and closed system. The compositional and isotopic changes of hydrocarbon gases generated from Paleogene coal with increasing maturation were investigated under semi-open and closed system laboratory pyrolysis to evaluate the maturity level at the time of hydrocarbon gas expulsion. Lower yields of saturated hydrocarbon gases and their higher  13 C values were observed in the semi-open system pyrolysis compared to those at the same maturity level in the closed system pyrolysis, since gaseous hydrocarbons depleted in 13 C were removed during semi-open system pyrolysis. The δ 2 H values of hydrocarbon gases generated in the closed system pyrolysis were initially lower than those in the semi-open system pyrolysis, and then became markedly higher at the higher maturity level (vitrinite reflectance [VR r ] > 1.2%), indicating significant hydrogenation of isotopically heavier inorganic hydrogen derived from water moisture in the coal matrix. The semi-open and closed system pyrolysis showed that the relationship between the isotopic composition of hydrocarbon gases expelled from coal and the maturity of coal depends on the state of openness or closedness of the hydrocarbon generation environment. Diagrams showing the relationship between the  13 C values of hydrocarbon gases expelled from Paleogene coal and the VR r under conditions intermediate between semi-open and semi-closed systems were proposed for evaluating the timing of hydrocarbon gas expulsion in sedimentary basins.

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“…Therefore, the vitrinite reflectance is regarded as the best rank parameter. Many correlations between the chemical composition of coal and vitrinite reflectance were derived; − however, when coals of fairly different maceral composition are used, these correlations become much poorer…”

Section: Introductionmentioning

confidence: 99%

The Heterogeneity of Coal Chemical Properties Derived from a Reflectogram

Tang¹,

Gupta²,

Sheng³

et al. 2004

Energy Fuels

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The proximate and ultimate analyses of a coal are regarded as sufficient to describe its chemical composition, and they have been widely used for practical applications. However, coal is actually a heterogeneous substance and is composed of different materials (macerals); therefore, the corresponding chemical compositions are average values of the individual composition of the macerals present in the coal. The reflectance distribution of a coal (the reflectogram), which shows the heterogeneity of the coal, can be represented by several reflectance bins. In this paper, the variation of chemical properties of a coal is differentiated by the difference in reflectance. The main focus of this paper is to establish correlations between chemical properties of a single reflectance bin and its reflectance from a maceral-independent approach and maceral-dependent approach. The bulk chemical properties (volatile matter (VM) content, ratio of hydrogen to carbon (H/C), etc.) of a coal then can be obtained by adding the properties of each individual reflectance bin together. Proximate and ultimate analyses with reflectogram analyses were conducted for 29 coal samples. A least-squares fit strategy was applied to derive the correlations, which were then used to predict the bulk properties of another eight samples. The relative error of the estimated VM from the maceral-dependent approach is 3.9%, whereas the relative error from the maceral-independent approach is 7.9%. No single reflectance bin data are available in the literature; therefore, comparisons between the properties of single reflectance bin from maceraldependent approach and bulk properties of maceral-rich fractions (bulk VM content versus mean maceral reflectance) in the literature have been made, and both show similar qualitative trends.

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Characteristic nature of sedimentation and coalification in the Tertiary system of the Japanese Islands

Cited by 15 publications

References 6 publications

Maceral Effects in the Determination of Proximate Volatiles in Coals

Maceral Effects in the Determination of Proximate Volatiles in Coals

Semi-open and closed system pyrolysis of Paleogene coal for evaluating the timing of hydrocarbon gas expulsion

The Heterogeneity of Coal Chemical Properties Derived from a Reflectogram

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