Pyrobitumen
Pyrobitumen | |
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General | |
Category | Organic matter |
Colour | Variable |
Pyrobitumen is a type of solid,
2, dichloromethane, and benzene-methanol
While the primary distinction between bitumen and pyrobitumen is solubility, the thermal processes driving the molecular cross-linking also decrease the atomic ratio of hydrogen to carbon from greater than one to less than one and ultimately to approximately one half. It should also be understood that both solubility and atomic H/C ratios form a continuum, and most solid bitumens have both soluble and insoluble components. The distinction between pyrobitumen and residual kerogen in a mature source rock is based on microscopic evidence of fluid flow within the rock fabric and is usually not determined.
The terms bitumen and pyrobitumen have related definitions in the Earth's crust and in the laboratory. In geology, bitumen is the product of deposition and maturation of organic matter. The
The terms bitumen and asphalt are often used interchangeably to describe highly viscous to solid forms of petroleum that have been used in construction since the fifth millennium B.C. Bitumen is distinct from tar, which properly describes a product formed by pyrolysis (destructive distillation) of coal or wood. Pitch recovered from petroleum by distillation is also sometimes called bitumen or asphalt.
Etymology
The expression "bitumen" originated in the Sanskrit, where we find the words jatu, meaning "pitch," and jatu-krit, meaning "pitch creating", "pitch producing" (referring to coniferous or resinous trees). The Latin equivalent is claimed by some to be originally gwitu-men (pertaining to pitch), and by others, pixtumens (exuding or bubbling pitch), which was subsequently shortened to bitumen.
Definition
Hunt
Classification
Archaic classification systems for classifying bitumens were constructed without the extensive knowledge of organic geochemistry developed over the past 50 years. Pyrobitumen was originally defined as a solid bitumen that is insoluble and infusible. The original classification system for solid bitumen of Abraham,[4] as adapted from Curiale,[5] is shown in Figure 1. Curiale says that while the historical classification scheme is useful for sorting museum collections, it is not useful for establishing genetic relationships, and he proposed the alternative classification shown in Figure 2.
Although there is not a direct relationship between the classification systems in Figures 1 and 2, one kind of pyrobitumen is a subset of the post-oil solid bitumen formed by thermal degradation of kerogen and oil. Of the 27 samples investigated by Curiale, the three impsonite samples had low solubility (<3%) and a low H/C ratio (<0.9) characteristic of highly mature organic matter. These samples also had the lowest asphaltene, highest aromatic, and highest volatile content in the soluble fraction. Carbon deposits associated with uranium nodules also had low solubilities and H/C ratios less than 1.0 and correspond to pyrobitumens with inorganic origins. For comparison, coal tar pitch has an atomic H/C ratio of about 0.8.[6] In the petroleum
Some archaic definitions of pyrobitumen include
References
- ^ B. P. Tissot and D. H. Welte (1984) Petroleum Formation and Occurrence, 2nd ed., Springer-Verlag, pp. 460–463.
- ^ J. M. Hunt, Petroleum Geochemistry and Geology, 2nd ed., Freeman, 1996, p. 437.
- ^ J. M. Hunt, Petroleum Geochemistry and Geology, 1st ed., Freeman, 1979, p. 28, 546.
- ^ H. Abraham (1945) Asphalts and Allied Substances, Van Nostrand-Rheinhold, page 62.
- ^ J. A. Curiale, Origin of solid bitumens, with emphasis on biological marker results, Org. Geochem. Vol. 10, pp. 559–580, 1986.
- ^ E. Fitzer, K.H. Dochling, H. P Boehm, and H. Marsh, “Recommended terminology for the description of carbon as a solid,” Pure Appl. Chem., Vol. 67, pp. 473–506, 1995.
- ^ M. D. Lewan, “Petrographic study of primary petroleum migration in the Woodford Shale and related rock units,” in (ed. B. Doligez) Migration of Hydrocarbons in Sedimentary Basins, Editions Technip, Paris, p.113-130.
- ^ http://www.spe.org/glossary/wiki/doku.php/terms:pyrobitumen, downloaded January 2, 2014.
- ^ J. M. Hunt, Petroleum Geochemistry and Geology, 2nd ed., Freeman, 1996, p. 597.
- ^ a b R. J. Hwang, S. C. Teerman, R. M. Carlson, “Geochemical comparison of reservoir solid bitumens with diverse origins,” Org. Geochem. Vol. 29, pp. 505–517, 1998.
- siliceous mudstones of the Mississippian Barnett Shale,” J. Sed. Res., Vol. 79, pp. 848–861 (2009).
- ^ A. K. Burnham and J. A. Happe, “On the mechanism of kerogen pyrolysis,” Fuel, Vol. 63, 1353–1356, 1984.
- ^ J. T. McCartney and S. Ergun, “Optical properties of graphite and coal,” Fuel, Vol. 37, pp. 272–281, 1958.
- ^ W. Kalkreuth, M. Steller, I. Wieschenkamper, and S. Ganz, “Petrographic and chemical characterization of Canadian and German coals in relation to utilization potential. 1. Petrographic and chemical characterization of feedcoals,” Fuel, Vol. 70, 683–694, 1991.
- ^ J. T. McCartney and M. Teichmuller, “Classification of coals according to degree of coalification by reflectance of the vitrinite component,” Fuel, Vol. 51, pp. 64–68, 1972.
- ^ P. K. Mukhopahyay, “Maturation of organic matter as revealed by microscopic methods: Applications and limitations of vitrinite reflectance, and continuous spectral and pulsed laser fluorescence spectroscopy, “in Diagenesis, III. Developments in Sedimentology, Vol 47, pp. 435–510, 1992.
- ^ K. E. Peters, C. C. Walters, J. M. Moldowan, The Biomarker Guide, Cambridge University Press, 2005, p. 1155.
- ^ J. L. Warner, D. K. Baskin, R. J. Hwang, R. M. K. Carlson, M. E. Clark, Geochemical Evidence for Two Stages of Hydrocarbon Emplacement and the Origin of Solid Bitumen in the Giant Tengiz Field, Kazakhstan, in P. O. Yilmaz and G. H. Isaksen, eds., Oil and gas of the Greater Caspian area: AAPG Studies in Geology 55, 2007, pp. 165–169.
- ^ M. L. Bordenave, Applied Petroleum Geochemistry, Editions Technip, Paris, 1993, pp. 106, 159.