Fuels kerogen

Oil shale deposits were formed in ancient lakes and seas by the slow deposition of organic and inorganic remains. The geology and composition of the inorganic minerals and organic kerogen components of oil shale vary with deposit locations throughout the world (1) (see also Fuel RESOURCES Petroleum). 

Synthetic fuels derived from shale or coal will have to supplement domestic suppHes from petroleum someday, and aircraft gas turbine fuels producible from these sources have been assessed. Shale-derived fuels can meet current specifications if steps are taken to reduce the nitrogen levels. However, extracting kerogen from shale rock and denitrogenating the jet fuel are energy-intensive steps compared with petroleum refining it has been estimated that shale jet fuel could be produced at about 70% thermal efficiency compared with 95% efficiency for petroleum (25). Such a difference represents much higher cost for a shale product. 

The kerogen content of different oil shales, i.e., the average yield of oil of an oil shale can vary greatly. Most oil shales have oil yields between 50 and 150 1 oil/t oil shale, rich shales may even yield more than 200 1/t. A particular characteristic of oil shale is its high areal density, which can exceed 1 million b/acre at its thickest (Bunger et al., 2004). Oil shale can also be used directly as fuel for electricity generation, as, for instance, in Estonia. However, oil shale is characterised by a low calorific value between 7.5 and 9 MJ/kg (based on LHV), which is about one fifth of the energy content of crude oil (Porath, 1999). 

Ashida, R., Painter, P., Larsen, J.W., Kerogen chemistry 4. Thermal decarboxylation of kerogens, Energy Fuels, 2005, 19, 1954. 

Lille, U., Heinmaa, I. Pehk, T. 2003. Molecular model of Estonian kukersite kerogen evaluated by 13C Mas NMR spectra. Fuel, 82, 799-804. 

Kerogen - [FUELS, SYNTHETIC - GASEOUS FUELS] (Vol 12) - [PETROLEUM - NOMENCLATURE IN THE PETROLEUM INDUSTRY] (Vol 18) - [OIL SHALE] (Vol 17) -role m petoleum origin [PETROLEUM - ORIGIN OF PETROLEUM] (Vol 18)... 

Electromagnetic radiation in the microwave frequency spectrum is absorbed most strongly by molecules with permanent dipole moments (4). The relaxation phenomenon of this absorbed power manifests itself in a heatlike reaction. The University of Colorado Oil Shale Project has studied the degradation of the liquid-fuel precursor (kerogen) by micro-wave interaction. Kerogen is a moderately strong absorber of this radia-... 

TTntil the recent years of renewed concern for alternative fuel oil and petrochemical sources, interest in the mineral shales which contain the earth s most abundant organic matter, kerogen, has been sporadic. Both in the United States and throughout the world there are vast shale reserves, but the technology to exploit them and extract the oil from... 

Burnham A. K., Braun R. L., Gregg H. R., and Samoun A. M. (1987) Comparison of methods for measuring kerogen pyrolysis rates and fitting kinetic parameters. Energy Fuels... 

Ganz H. and KalMeuth W. (1987) Application of infrared spectroscopy to the classification of kerogen-types and the evaluation of sotrrce rock and oil shale potentials. Fuel 66, 708-711. 

Two examples in which the solid itself is reactive are the shale oil retorts of Figure 17.29. Crushed oil shale is charged at the top, air and gaseous fuel at the bottom. When the shale moving downward reaches a temperature of 900°F, the kerogen decomposes into oil vapor, gas, and carbonaceous residue. There are many designs of pilot plant retorts, but the only commercial units at present are in the USSR and China. 

Results are reported here for experiments made on a Sydney basin oil shale from Glen Davis and on a Julia Creek shale and its demineralized organic residue. These specimens were obtained from CSIRO Division of Fossil Fuels and CSIRO Division of Energy Chemistry respectively. We do - not have analyses of these specimens but they are considered typical of the particular deposits, H/C ratios of 1.52 and 1.4 and 0/C ratios of 0.04 and 0.8 for Glen Davis and Julia Creek kerogens respectively have been published (8) ... 

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