That, 1 ike the isoprenoids, have specif ic animal or plant precursors Many of the cycloalkanes or saturated r ing structures, also calledĬycloparaff ins or naphthenes, consist of important minor constituents Isoprenoids, and while the C10-C20 isoprenoids are often ma jor Pristane (Cl") and phytane (C20) are usually the most abundant Is the isoprenoid hydrocarbons consisting of isoprene building blocks. Above C13, the most important group of branched compounds Usually around 40, although compounds with 60 carbons have been Of the gener al molecular formula (CnH2n+2 ), with n r ang ing f rom 1 to Saturated normal alkanes (also called paraffins) and branched alkanes The alkanes, or aliphatic hydrocarbons, consist of the fully Petroleum hydrocarbons (Figure 1-1) consist of alkanes,Ĭycloalkanes, and aromatic compounds containing at least one benzene Table 1-1 presents examples of the composition of crude oils andįuel oils. Widely varying concentrations of trace metals such as V, Ni, Fe, Al, Often collectively referred to as NSO compounds. Present as elemental sulfur or as heterocyclic constituents andįunctional groups. Nitrogen (0-1%), and oxygen (0-5%) are important minor constituents Hydrogen (10-15~) are the main elements in petroleum, sulfur (0-10%) Ĭlark and Brown, 1977 I, although the major ity of crude oils contain the In crude oils, accounting for 50-989 of the total composition (R.C. " Hydrocarbons are the most abundant compounds Crude oils contain thousands of different chemicalĬompounds owing to processes dur ing petroleum formation resulting in
Producing regions, and even from within a particular formation, can The chemical composition of crude oils from different Otherwise noted, those texts are the sources for the following
Recently by Tissot and Welte (1979) and Hunt (1980), and unless Petroleum formation and composition have been discussed in detail Istics of the hydrocarbon sources to the mar ine environment and This section bight ights the main compositional character. Vated by chemical and microbial alterations that occur after intro-ĭuction of a particular set of hydrocarbon compounds to the mar ineĮnvironment, a set originally attributable to a source but subsequently The interpretive dilemma becomes further aggra. Geochemist in associating a given complex hydrocarbon a~s~mblaa" with Thus, the analytical chemist faces a challenge in der iving detailedĬompositional data on a given environmental sample as does the bio. Sources of hydrocarbons enter ing the mar ine environment are numerous,Īnd the number of individual hydrocarbon components are quite large. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages. Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book.
0 kommentar(er)
