Petroleum-derived hydrocarbons

Wakeham [14] has discussed the application of synchronous fluorescence spectroscopy to the characterization of indigenous and petroleum derived hydrocarbons in lacustrine sediments. The author reports a comparison, using standard oils, of conventional fluorescence emission spectra and spectra produced by synchronously scanning both excitation and emission monochromators. 

There are several reasons why the data for total petroleum hydrocarbons do not provide ideal information for investigating sites and establishing target cleanup criteria. For example, use of the term total petroleum hydrocarbons suggests that the analytical method measures the combined concentration of all petroleum-derived hydrocarbons, thereby giving an accurate indication of site contamination. But this is not always the case. Furthermore, target cleanup levels based on total petroleum hydrocarbons concentrations implicitly assume (1) that the data are an accurate measurement of petroleum-derived hydrocarbon concentration, and (2) the data also indicate the level of risk associated with the contamination. These assumptions are not correct due to many factors, including the nonspecificity of some of the methods used and the complex nature of petroleum hydrocarbons and their interaction with the environment over time. 

There are many analytical techniques available that measure total petroleum hydrocarbon concentrations in the environment, but no single method is satisfactory for measurement of the entire range of petroleum-derived hydrocarbons. In addition, and because the techniques vary in the manner in which hydrocarbons are extracted and detected, each method may be applicable to the measurement of different subsets of the petroleum-derived hydrocarbons present in a sample. The four most commonly used total petroleum hydrocarbon analytical methods include (1) gas chromatography (GC), (2) infrared spectrometry (IR), (3) gravimetric analysis, and (4) immunoassay (Table 7.1) (Miller, 2000, and references cited therein). 

Reinhard, M. (1993). In situ bioremediation technologies for petroleum- derived hydrocarbons based on alternate electron acceptors (other than molecular oxygen). In In Situ Bioremediation of Ground Water and Geological Material A Review of Technologies, ed. R. D. Norris et al., section 7, pp. 7.1-7.7. EPA/600/R-93/124. NTIS Document No. PB93-215564, Washington, DC. 

FEEDSTOCKS. Gaseous or liquid petroleum-derived hydrocarbons or mixture of hydrocarbons from which gasoline, fuel oil. and petrochemicals are produced hy thermal or catalytic cracking. It is also called charging slock. Feedstocks commonly used include ethane, propane, butane, hutene. benzene, loluene. xylene, maphtha, and gas oils. 

On the more practical side, vast quantities of simple alcohols—methanol, ethanol, 2-propanol, 1-butanol—and many ethers are made from petroleum-derived hydrocarbons. These alcohols are widely used as solvents and as intermediates for the synthesis of more complex substances. 

This profile covers total petroleum hydrocarbons (TPH), which is defined as the measurable amount of petroleum-based hydrocarbon in an environmental medium (Chapter 2). TPH is measured as the total quantity of hydrocarbons without identification of individual constituents. Sources of TPH contamination in the environment range from crude oil, to fuels such as gasoline and kerosene, to solvents, to mineral-based crankcase oil and mineral-based hydraulic fluids. These products contain not only a large number and variety of petroleum hydrocarbons, but also other chemicals that, strictly speaking, are not the subject of this profile, such as non-hydrocarbon additives and contaminants. The TPH issue is further complicated by the number of petroleum-derived hydrocarbons that have been identified—more than 250—and the variability in composition of crude oils and petroleum products (see Section 3.2 and Appendices D and E for details). 

Petroleum-derived hydrocarbons and their metabolites (e.g., fatty acids), especially those in the aliphatic and aromatic EC>16-EC35 fractions, tend to accumulate in the liver, spleen, and adipose tissues. There are no known clinical methods to facilitate or accelerate removal of petroleum hydrocarbons or their metabolites from these tissues. 

Carbonized coal products have a unique fingerprint by both GC and fluorescence analyses. Both these fingerprints confirm that sediments from the Elizabeth River are contaminated with carbonized coal products and allow for the detection of carbonized coal hydrocarbons, even in the presence of petroleum-derived hydrocarbons. Fluorescence allows for the rapid analysis of more samples and shows the contamination within the Elizabeth River to be widespread. Carbonized coal products in the sediments may constitute a chronic long-term source of PNA s to the water column. 

Crude oil and the products derived from it are a complex mixture of compounds which change over time and distance when released into the environment. Added to this is the uncertainty related to definitions - for example, total petroleum hydrocarbons (TPH), often referred to as oil and grease, mineral oil, hydrocarbon oil and extractable hydrocarbons. Also, there are many analytical techniques available for measuring TPH concentrations. No single method measures the entire range of compounds covered by petroleum-derived hydrocarbons. 

Blumer, M. and Sass, J., 1972. Indigenous and petroleum-derived hydrocarbons in a polluted sediment. Mar. Pollut. Bull., 6 92—94. 

Most syngas is produced captively for the manufacture of methanol from natural gas. Natural gas is reformed with steam to produce a raw syngas which enters a methanol synthesis reactor and is converted directly to methanol. Methanol is not regarded as a petrochemical, as it is usually produced from natural gas rather than a petroleum-derived hydrocarbon, but it is used as feedstock to produce a great many petrochemicals. Syngas is also used as feedstock in the 0x0 process to produce a wide variety of aldehydes and alcohols. 

API. 1987a. Acute inhalation toxicity evaluation of a petroleum derived hydrocarbon in rats - API 84-02 and API 85-01 with heavy thermal cracked naphtha, with cover letter dated 05/19/87. Project no. 22235-14. Washington, DC. American Petroleum Institute. 

Oil pollution and its physical, chemical and biological effects appear to be inevitable consequences of the production, transport and use of mineral oil and its products. A vast number of publications, too numerous to be cited here, demonstrate that petroleum-derived hydrocarbons have been distributed widely in the marine environment. 

Not infrequently, even research vessels are sources of petroleum which rapidly forms a plume around the ship when on station. Therefore, samples for the determination of petroleum-derived hydrocarbons in seawater should be taken immediately after the ship has come to a stop. If this is not possible, one might consider rowing a rubber dinghy some distance upwind from the ship to take the samples (do not use an outboard engine). 

The fuel of choice for Rudolph Diesel s internal combustion engine, introduced to the world at the Paris Exposition in 1900, was peanut oil. Coming full circle after over a century, so-called biodiesel fuels have become popular alternatives to the petroleum-derived hydrocarbon mixtures widely used in diesel engines. Rudolph Diesel eventually found that pure vegetable oil was too viscous to be practical... 

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