Element speciation analysis of petroleum and related materials

An EXAFS and XANES Study of V, Ni, and Fe Speciation in Cokes for Anodes Used in Aluminum Production

“…The metals V and Ni in coke are derived from crude oil. In crude oil these elements are found as soluble organometallic complexes, dominated by porphyrins where the metal is coordinated to N [17][18][19] and also non-porphyrin organic complexes where the metal is coordinated to S or O [20] [21]. The V is mostly as porphyrins in the more widely studied maltene (light) fraction of crude oil, but it is also present in porphyrins in the asphaltene (heavier) fraction [19].…”

“…It has the very substantial advantage over X-ray diffraction techniques for crystal structure in that the structure of interest may be very dilute and highly dispersed and still be tractable by EXAFS. The metals V and Ni are present in crude oil in large part as soluble organometallic complexes such as porphyrins where the metal is coordinated to N [17][18][19] and also non-porphyrin organic complexes where the metal is coordinated to S or O [20] [21]. The metals concentrate in the heavy fractions and thus in the coke by-product rather than the light fractions.…”

Behavior of Re and Os during contact between an aqueous solution and oil: Consequences for the application of the Re–Os geochronometer to petroleum

“…Though both elements are chalcophile, the fact that transfer occurs very efficiently in both sulfur poor (P-oil) and sulfur-rich (V-oil) oils suggests that sulfur does not play a critical role, or at least that its role is hidden by an even stronger affinity of Re and Os for organic material. Re and Os, like many other metals (Ali et al, 1983(Ali et al, , 1993Caumette et al, 2009), are principally located in the heavy fraction of oil (asphaltenes; Selby et al, 2007). Moreover, within the asphaltene fraction, Re and Os are both concentrated in the most polar constituents, suggesting a similar mode of incorporation (Mahdaoui et al, 2013).…”

Separation of Heavy Crude Oil Emulsions Using Microwave Radiation for Further Crude Oil Analysis

“…In general, these elements are associated with organic compounds (36). Nickel and vanadium are present in crude oil generally as metalloporphyrins (37,38) and sulfur occurs mainly as hydrogen (39).…”