Record details

    The effect of pyrolysis condition on the assessment of the origin of bitumens and coals from the Bohemian Massif (Czech Republic)
Statement of responsibility
    Jiří Čejka, Zdeněk Sobalík, Luboš Holý, Bohdan Kříbek
    Čejka, Jiří
    Holý, Luboš
    Kříbek, Bohdan, 1946-
    Sedláček, Václav
    Sobalík, Zdeněk
Source title - monograph
    Weathering of Fossil Organic Matter
    s. 49-60
    4 obr., 1 tab., 3 s.bibl.
Subject group
    břidlice černá
    organická substance
    plzeňská pánev
    sokolovská pánev
Geographical name
Abstract (in english)
   The composition of fossil organic matter of different origin and thermal maturation has been studied using gas chromatographic-mass spectrometric characterisation of its pyrolysis products. It has been found that the relative concentration of pyrolysis products obtained from the individual samples depends on the pyrolysis temperature and duration. An increase in the pyrolysis temperature from 300 to 500°C caused cracking of the aliphatic hydrocarbons resulting in shortening of the n-alkaline chains. High yields of pyrolysis products can be obtained at temperatures above 350°C; on the other hand, suppression of cracking reactions can be achieved for relatively short duration of pyrolysis. the optimal pyrolysis conditions for fossil organic matter investigated can be suggested s follows: temperature range 400-450°C, duration 10-60 minutes depending on the amount of organic matter present in the sample.
   Then the chromatographic patterns clearly reflect the origin of the organic matter and the degree of its thermal maturation in the rocks. While aliphatic hydrocarbons predominated in the pyrolysis products of organic matter originating in marine or lacustrine, algae-dominated environments, benzene, alkylbenzenes, alkylnaphthalenes and azulenes formed a substantial part of the pyrolysis products obtained from organic matter derived mostly from continental plants (brown and black coal). In Silurian black shale, the organic matter underwent a very high degree of thermal maturation and produced only short-range alkanes and a small amount of alkylnaphthalenes. The amount of pyrolysate obtained from various samples correlates with their Rock-Eval hydrogen index (IH). This indicates that the pyrolysate yield is depended on the H/C ratio in the fossil organic matter
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
Entered date
    28. 3. 2008
Import date
    8. 8. 2012