Kerogen chemical composition

Their chemical compositions are very complex and depend essentially on their age, that is, the phase of development of the kerogene, regardless of the origin of the crude (Speight, 1991) (see Chapter 1). 

The Murchison meteorite shown in Figure 6.7, like all meteorites, is named after the place from which it was recovered and in this case it is the town of Murchison, Victoria in Australia about 100 km north of Melbourne. The fall occurred in 1969 and was followed by an analysis of the chemical composition in some considerable detail. The Murchison meteorite is a carbonaceous chondrite containing about 2 per cent carbon, some as inorganic carbonates, and some as soluble compounds such as amino acids but the bulk as a macromolecular heterogeneous material referred to as kerogen. 

The chemical compositions of oil shales and oil shale kerogen have been studied extensively (20). However, little work has been done to integrate chemical composition data in order to aid in the selection of suitable extracting processes. In this study, five analysis methods were used to chemically characterize the samples. These methods included Rock-Eval analysis, Fischer analysis, Xi C NMR, Ultimate analysis, and X-ray diffraction mineral analysis. 

In crude and by-product oils, the paramagnetic species presence allows that the RPE technique assists to elucidate the complex chemical composition of these systems. Petroleum and related materials such as heavy oils, asphalt, pitch coal tar, tar sands, kerogen, and oil shale have been studied by EPR (Ikeya, 1993). 

Molecular Composition of Brazilian oil shales. Oil shales may be considered as composed of two main (chemical) phases an inorganic phase, constituted of mineral species (crystaline and/or amorphous) and an organic phase that, in its turn, can be divided into two oth er (sub) phases the bitumen, the soluble (in organic solvents) frac tion and the kerogen defined as the insoluble organic matter of organic. 

Hatcher, P. G. (1980). The origin, composition, chemical structures and diagenesis of humic substances, coals and kerogens as studied by nuclear magnetic resonance. Ph.D. dissertation, University of Maryland, 283 pp. 

Recently, there have been a number of studies using computational chemistry techniques to model macromolecules of kerogens (Faulon et al. 1990), coals (Carlson 1992 Nakamura 1993 Murata et al. 1993 Faulon et al. 1994), asphaltenes (Murgich et al. 1996 Kowalewski et al. 1996 Diallo et al. 1998), wood and lignin (Faulon 1994, 1995 Faulon and Hatcher 1994), and biomarkers (Peters et al. 1996 Peters 2000). Computational chemistry models have been used to predict a variety of physical and chemical properties, such as the density of coals (Nakamura et al. 1993 Murata et al. 1993), the microporosity of coals (Faulon 1994, 1995), and the self-association of asphaltenes and resins (Murgich et al. 1996 Subramanian and Sheu 1997 Zajac et al. 1997). Oil companies and petroleum research organizations are interested in compositional and structural chemistry of these macromolecules because of its potential for solving both upstream and downstream problems. 

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