Hydrocarbons in crude oil

Ellis, L., Aromatic hydrocarbons in crude oil and sediments Molecular sieve separations and biomarkers, RhD thesis, Curtin University of Technology, 1994. 

Nathwani, J.S., Philip, C.R. (1977) Absorption-desorption of selected hydrocarbons in crude oils on soils. Chemosphere 6, 157-162. 

Pancirov, R.J. and Brown, R.A. Analytical methods for pol3muclear aromatic hydrocarbons in crude oils, heating oils and marine tissues, in Proceedings of Joint Conference on Prevention and Control of Oil Pollution, American Petroleum Institute, pp. 103-115, 1975. 

Rueter, P., Rabus, R., Wilkes, H., Aeckersberg, F., Rainey, F. A., Jannasch, H. W. Widdel, F. (1994) Anaerobic oxidation of hydrocarbons in crude oil by new types of sulphate-reducing bacteria. Nature, 372, 455-8. 

Most of the hydrocarbons in crude oil belong to the family of compounds called alkanes. The molecules within the alkane family contain carbon atoms covalendy bonded to four other atoms by single bonds (Figure 14.2). Because these molecules possess only single bonds they are said to be saturated, as no further atoms can be added. This can be seen in the bonding scheme for methane (Figure 14.3). The physical properties of the first six members of the alkane family are shown in Table 14.1. 

Volkman J. K., Alexander R., Kagi R. L, Rowland S. J., and Sheppard P. N. (1984) Biodegradation of aromatic hydrocarbons in crude oils from the Barrow SubBasin of western Australia. Org. Geochem. 6, 619-632. 

Hsieh M. and Philp R. P. (2001) Ubiquitous occurrence of high molecular weight hydrocarbons in crude oils. Org. Geochem. 32, 955-966. 

Light ends — This is a term used to describe the low molecular weight, volatile hydrocarbons in crude oil and petroleum products. The light ends are the first compounds recovered from crude oil during the fractional distillation process and are the first fractions of spilled oil to be lost through evaporation. 

Fig. 4. 25 Some important biomarker hydrocarbons in crude oils (n.b. numbering system for cheilanthanes is based on the C25 parent sesterterpane and so is different from the hopanoidal system).

As will be discussed later, most of the volatile (and soluble) hydrocarbons in crude oils and light refined products have less than 10 carbon atoms in the molecule. These hydrocarbons, especially the aromatics, are... 

Radke M., Garrigues P. and Wilsch H. (1990b) Methylated dicyclic and tricyclic aromatic hydrocarbons in crude oils from the Handil field, Indonesia. Org. Geochem. 15, 17-34. 

NMR and to some extent NMR spectroscopy are very important analytical tools to measure the content and composition of the alkanes and other hydrocarbons in crude oils , naphtha, bitumenous rocks, liquified coal products " , gasoline ", diesel fuels ° and the like. Rapid and reliable detection of the main components is of high practical importance, and gave rise to numerous reports on analytical procedures and results. Quantitative methods involving NMR have been developed, and the results checked by statistical methods such as principal component analysis ... 

The ESA-Py mass spectra are then used to rapidly distinguish synthetic polymer standards that differ in the nature of their building units, degree of polymerization, and copolymerization coefficients. In addition, a petroleomic application of ESA-Py/MS was also demonstrated. Trace polar compounds that coexist with large amoimts of nonpolar hydrocarbons in crude oil, amber, humic substances, and rubber samples were selectively ionized without any chromatographic separation or complicated pretreatment processes. 

The paraffins are also called methane series, and comprises most common hydrocarbons in crude oil. The paraffins that are liquid at normal temperature boil between 40-200 °C. The naphthenes are saturated closed ring series and are important part of all liquid refinery products. The aromatics are unsaturated closed ring series. Benzene is most common of the series and is present in most of the crude oils, but aromatics constitute a small fraction of all crudes. 

In spite of the above evidence, an exhaustive inquiry by Updegraff and Wren (1954) could not confirm the anaerobic utilization of hydrocarbons in crude oil or of -hexadecane by a number of strains of sulfate-reducing bacteria, including several obtained from ZoBell s laboratory. Updegraff and Wren (1954, p. 320) concluded that ... definite proof of the ability of sulfate-reducing bacteria to oxidize petroleum hydrocarbons is not to be found in the literature. ... 

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