Nickel and vanadyl porphyrins in Saudi Arabian crude oils

Abstract

This study reports the isolation and characterization of nickel and vanadyl porphyrins in the residue (535 °C+) and asphaltenes from Arabian Heavy crude oil. The residue was obtained by distillation of crude oil, whereas the asphaltenes were precipitated by rc-heptane from the crude oil. Metalloporphyrins were first extracted from the residue and the asphaltenes. The nickel porphyrins were separated from vanadyl porphyrins by means of adsorption chromatography on silica gel and alumina using solvents of increasing polarity. The chromatographic separation process was monitored by ultraviolet-visible spectrophotometry. Both nickel and vanadyl porphyrins were identified and characterized by ultraviolet-visible spectrophotometry and mass spectrometry.been fully or partially established. Types of these porphyrins and their structures are also listed.

Removal of Nickel and Vanadium from Heavy Oils Using Supercritical Water

“…The exact molecular form of these metal complexes is still controversial among the researchers within this field. Treibs 29a) 29c) was the first to demonstrate the presence of MPs of V and Fe in a wide range of petroleums and bitumens 30) ; those of Ni were identified later. This discovery spurred searches for these complex compounds in a variety of samples of different geological origins.…”

Nickel removal from nickel-5,10,15,20-tetraphenylporphine using supercritical water in absence of catalyst: A basic study

“…Nickel and vanadium are present in heavy oils forming porphyrinic structures [7,8]. Most studies to date have utilized porphyrin chelates [9,10]. There are basically four methods for the removal of metals from heavy oils and residuum fractions: physical, chemical, electrochemical and catalytic treatment processes [8,11].…”

“…Hung and Wei [2], Agrawal and Wei [6], Ware and Wei [7], Garcia-Lopez et al [5] studied reaction kinetics in the presence of unsulfided catalyst while Weitkamp et al [13], Chen and Massoth [14], Bonné et al [15] carried out additional studies in the presence of sulfide catalyst. These researchers explored valuable study in the temperature ranges 125-400 • C. These efforts removed 90% metals implying high investment, operation cost and longer reaction time (8-9 h) [2][3][4][5][6][7][8][9][10][11][12][13][14][15]. It was Bonné et al [16] and Rankel [17] whom studied HDM reactions in the absence of a catalyst showing that conversion of Ni-TPP was low without a catalyst, but hydrogen sulfide has the capability to promote the conversion of Ni-TPP.…”

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a b s t r a c tReactions of 10,15, were studied in supercritical water in the presence of toluene without the addition of any catalyst, H 2 or H 2 S that is called a green process. The objective of this study was to remove nickel from Ni-TPP, the most common metal compound present in heavy crude, in high extent at low reaction time.

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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).…”