Bitumen analysis

The most common solvent used for extraction of bitumen from dried sediments is dichloromethane (CHjClj) with a small admixture (e.g. 1%) of methanol, 

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Another interesting, but rather complex system, which couples flow injection analysis, EC and GC has been recently reported (47). This system allows the determination of the total amount of potentially carcinogenic polycyclic aromatic compounds (PACs) in bitumen and bitumen fumes. This system could also be used for the analysis of specific PACs in other residual products. 

These are semisolid or solid substances formed in nature from crude oils after the volatile components have evaporated and the remainder has undergone oxidation and polymerization. They are also referred to as bitumens, waxes, and pitch. These materials are believed to consist of mixtures of complex organic molecules of high molecular weight. As with crude oils, which contain thousands of different chemical compounds, an exact chemical analysis for identification and composition is impractical to perform on the solid deposits of petroleum. 

Recovering the bitumen is not easy, and the deposits are either strip-mined if they are near the surface, or recovered in situ if they are in deeper beds. The bitumen could be extracted by using hot water and steam and adding some alkali to disperse it. The produced bitumen is a very thick material having a density of approximately 1.05 g/cm. It is then subjected to a cracking process to produce distillate fuels and coke. The distillates are hydrotreated to saturate olefinic components. Table 1-8 is a typical analysis of Athabasca bitumen. ... 

The analysis of geochemical liquids such as crude oils, hydrothermal bitumens, extracts of coals, and host rocks containing dispersed organic matter or pyrolysates... 

Generally, only a very small amount of visible organic residue is required for analysis. If it is pure organic material (e.g., if it has the same appearance as a modern resin or bitumen), then a pinhead sized piece (a few milligrams) is usually sufficient. With samples on this scale, however, heterogeneity within... 

By far the most widespread use of NMR in an on-line production environment is the utilization of downhole exploration tools by petroleum service companies such as Schlumberger, Halliburton, and Baker Hughes. Articles on these unilateral NMR systems are found in the patent databases, " academic literature, and on-line resources provided by the exploration companies. The references provided here are just a few examples in a very prolific field. The technique is applied in high-temperature and pressure situations and currently is used down to a depth of about 10 km (6 miles) to produce a picture of water/oil content in the adjacent rock formations as well as to derive permeability, diffusivity, and hydrocarbon chemistry information. Mobile unilateral NMR systems such as the NMR-MOUSE are also being developed in order to take benchtop NMR systems into the field to perform analysis of geological core samples at the drill site. NMR analyzers are also being developed to determine the bitumen content and properties in tar sand production and processing. " " ... 

Mary s City, 364-375 Bulk isotopic analysis (S13C and SD), asphaltene in bitumen samples, 141-149... 

Mesopotamian glazed ceramics, 430-433,435/, 437-440 obsidian sourcing, 278,279-281 See also Neutron activation analysis Intermountain Region, North America, historic pottery, 447-459 Iran, Neolithic, bitumen traces in ceramic vessels, 137-151 Iran, Neolithic sites Ali Kosh, 138, 139/... 

Table III. Chemical Analysis and Molecular Weights of Tar Sands Bitumen, Coal Liquids, and Their Fractions...

Table II. Analysis of Unozonized and Partly-Ozonized Bitumen...

Simulated Distillation of Bitumen Sample. The boiling-range distribution of the recovered bitumen was determined by simulated distillation gas-liquid chromatography using the procedure of Poulson et al. (15). Boiling points are determined by calibration with a mixture of n-paraffins ranging from Cn to C42. The upper limit for boiling point determination in this analysis is about 540°C (1000°F). 

Neutral Lewis bases were removed by contacting the acid- and base-free bitumen with ferric chloride/Attapulgus clay in a column system. Weakly adsorbed complexes were desorbed with 1,2-dichloroethane while strongly held complexes were desorbed with benzene and methanol. This procedure provided two neutral Lewis bases fractions for analysis. 

The elemental analysis of oil sand bitumen (extra heavy oil) has also been widely reported (Speight, 1990), but the data suffer from the disadvantage that identification of the source is too general (i.e., Athabasca bitumen which covers several deposits) and is often not site specific. In addition, the analysis is quoted for separated bitumen, which may have been obtained by any one of several procedures and may therefore not be representative of the total bitumen on the sand. However, recent efforts have focused on a program to produce sound, reproducible data from samples for which the origin is carefully identified (Wallace et al., 1988). It is to be hoped that this program continues as it will provide a valuable database for tar sand and bitumen characterization. 

The major exception to these narrow limits is the oxygen content of bitumen, which can vary from as little as 0.2% to as high as 4.5%. This is not surprising, since when oxygen is estimated by difference the analysis is subject to the accumulation of all of the errors in the other elemental data. Also, bitumen is susceptible to aerial oxygen and the oxygen content is very dependent upon the sample history. In addition, the ultimate composition of the Alberta bitumen does not appear to be influenced by the proportion of bitumen in the oil sand or by the particle size of the oil sand minerals. 

However, in order to define conventional petroleum, heavy oil, and bitumen, the use of a single physical parameter such as viscosity is not sufficient. Other properties such as API gravity, elemental analysis, composition, and, most of all, the properties of the bulk deposit must also be included in any definition of these materials. Only then will it be possible to classify petroleum and its derivatives (Speight, 1999). 

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