Ultimate analysis of petroleum

The ultimate analysis (elemental composition) of petroleum is not reported to the same extent as it is for coal (Speight, 1994). Nevertheless, there are ASTM procedures (ASTM, 1995) for the ultimate analysis of petroleum and petroleum products but many such methods may have been designed for other materials. 

The elemental composition (ultimate analysis) of petroleum, no matter what the origin of the particular petroleum, varies only slightly over very narrow limits (Chapter 1) ... 

Sec. 1.7 Physical and Chemical Properties of Compounds and Mixtures 57 TABLE 1.8 Ultimate Analysis of Petroleum Crude... 

Three different carbon particles were used in these experiments char which was produced by the carbonization of non-coking Taiheiyo coal at 800°C, activated carbon produced from petroleum residuals, and graphite of high purity. The ultimate analysis of these carbons are given in Table I. 

The computation of maximum volatile nitrogen yield was based upon the ultimate analysis of the chars generated at all drop tube furnace temperatures from 1000 C to 1700 C. Petroleum coke can have significant concentrations of fuel nitrogen measured in g/GJ (lb/10 Btu) as shown in Table 2.3. Further, this nitrogen can be concentrated more heavily in the char than the nitrogen in coal. 

As already noted, the chemical composition of petroleum and petroleum products is complex and may change over time following release into the environment. These factors make it essential that the most appropriate analytical methods are selected from a comprehensive hst of methods and techniques that are used for the analysis of environmental samples (Dean, 1998 Miller, 2000 Budde, 2001 Sunahara et al., 2002 Nelson, 2003 Smith and Cresset, 2003). But once a method is selected, it may not be the ultimate answer to solving the problem of identification and, hence, behavior (Patnaik, 2004). There are a significant number of petroleum hydrocarbon-affected sites, and evaluation and remediation of these sites may be difficult because of the complexity of the issues (analytical, scientific, and regulatory not to mention economic) regarding water and soil affected. 

As early as 1833, Dumas (37) made the statement that, based on the results of the ultimate analyses of crudes, they consisted essentially of hydrocarbons, in spite of the fact that they had different sources. Mabery (107) after many years of arduous labor to determine the hydrocarbon composition of crude oils came to a similar conclusion in 1903. He concluded that petroleum from whatever source is one and the same substance, consisting of a mixture of a few series of hydrocarbons in variable proportions, and no matter what field the oil comes from, it only varies from oil from other fields in its content of these series of hydrocarbons, the members of the series varying from one crude to another. In the same paper, where Mabery summarized his work in 1903, he said in substance that he had been working with the financial assistance of the C. M. Warren Fund, but that lack of adequate money for research on the composition of petroleum was a serious handicap. He added that if 5,000 could be obtained from the Carnegie Institute, a really thorough analysis could be made. 

As regulations regarding the environmental impact of petroleum products like fuels and lubricants become more and more strict, the need for accurate and fast chemical analysis increases. Moreover, accurate and fast chemical analysis also strongly supports the production and ultimately the quality of the end product. The demand to reduce the concentrations of possibly harmfiil elements like sulfur imposes new challenges for detection technology. 

Typically, petroleum residue is characterized by proximate analysis, which only quantifies the fraction of fuel material (FM), ash and moisture, and elemental (ultimate) analysis (C, H, O, N, S). In the proximate analysis, the fuel fraction is usually divided into two parts fixed carbon (FC) and volatile material (VM). For calculation purposes, both fractions are totalized as ash-free dry fuel matter (expressed in weight%). With the elemental analysis (reported in weight% dry basis for each element), it is possible to obtain the condensed formula of the fuel fraction and thus its molecular weight. 

In the same way, the energy our bodies need to keep warm, move about, and build new tissue comes from a food reserve carbohydrates, chiefly in the form of starch. (We eat other animals, too, but ultimately the chain goes back to a carbo-hydrate-eater.) In the final analysis, we get energy from food just as we do from petroleum we oxidize it to carbon dioxide and water. 

The early investigators, by repeated fractional distillation, were able to determine that crude petroleum consisted principally of hydrocarbons. Ultimate analyses had shown that relatively small proportions of sulfur, nitrogen, and oxygen were usually present, probably in the form of derivatives. They were able to identify a number of hydrocarbon types such as paraffins, cycloparaffins, and aromatics, and even to isolate some members of these series in a qualitative way. The state of the art was very well summed up by Hoefer (1888) (65) when he wrote in his book Das Erdol as follows It should be pointed out that up to the present no complete quantitative analysis has been carried out on any crude petroleum, that we must be content rather to discover which are the principal types of hydrocarbons present, which predominate and, qualitatively, to identify the individual members of such series. ... 

Fuel oil, therefore, in its various categories has an extensive range of applications, and the choice of a standard procedure to be used for assessing or controlling product quality must, of necessity, depend on both the type of fuel and its ultimate use. But first, as for all petroleum analysis and testing, the importance of correct sampling of the fuel oil cannot be overemphasized, because no proper assessment of quality can be made unless the data are obtained on truly representative samples (ASTM D-270, IP 51). 

A compilation of properties of several selected heavy crude oils is shown in Table 1.1. As can be seen, heavy crude oils exhibit a wide range of physical and chemical properties. Whereas the properties such as viscosity, density, boiling point, and color may vary widely, the ultimate or elemental analysis varies over a narrow range for a large number of samples. The carbon content is relatively constant, while the hydrogen and heteroatom contents are responsible for the major differences between petroleum. Nitrogen, oxygen, and sulfur can be present in only trace amounts in some heavy crude oils, which consist primarily of hydrocarbons. 

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