Porphyrins in Heavy Petroleums: A Review

The petroleum industry is increasingly concerned with the conversion of vacuum residues as a consequence of decreased conventional crude oil availability. The compositional analysis of heavy oil products has become a key step in conversion processes, but the complexity of these oil matrices tends to increase with their boiling point. In this study, comprehensive two-dimensional liquid chromatography (LCxLC) coupled to inductively coupled mass spectrometry (ICP-MS/MS) is considered with a view to meet new requirements and to bring additional information regarding the species present in these matrices. In search for a high degree of orthogonality, two separation techniques involving two different retention mechanisms were evaluated: Size Exclusion Chromatography (SEC) and Reverse Phase Liquid Chromatography (RPLC). In SEC, the analytes are separated according to their molecular weight while according to their hydrophobicity in RPLC. The separation power of both individual separation techniques was first evaluated. Off-line and on-line LCxLC were compared on the basis of an optimization approach. It is shown that off-line SECxRPLC can provide, for the same analysis time of 150 min, a higher peak capacity (2600 vs 1700) while a similar dilution factor (close to 30) but also requires far fewer fractions to be analyzed (12 vs 2 400). Asphaltenes which constitute the heaviest fraction of crude oils (obtained from petroleum industry) were analyzed by the developed off-line SECxRPLC method. The resulting 2D-contour plots show that co-elutions could be removed leading, for the first time, to new information on high molecular weight species containing sulfur and vanadium.

show abstract

“…Porphyrins, chelated with nickel and vanadyl, are widely described in the literature [5][6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Comprehensive two-dimensional liquid chromatography with inductively coupled plasma mass spectrometry detection for the characterization of sulfur, vanadium and nickel compounds in petroleum products

Bernardin

Masle

Bessueille-Barbier

et al. 2020

Journal of Chromatography A

View full text Add to dashboard Cite

show abstract

“…[2][3][4] V and Ni contained in heavy oil are usually in the form of porphyrin, aetioporphyrin, or non-porphyrin complexes. 5 Although metal removal can be achieved by hydrodemetallization, the catalyst will be irreversibly deactivated because of the deposition of V and Ni on the catalyst surface. In order to extend the operating cycle of fixed-bed hydrogenation reactors, the total concentration of V and Ni in the heavy oil feed must not exceed 120 ppm.…”

Section: Introductionmentioning

confidence: 99%

Demetallization of heavy oil through pyrolysis: A reaction kinetics analysis

et al. 2020

View full text Add to dashboard Cite

By tracking the transfer of vanadium and nickel in pyrolysis products, a seven‐lump reaction kinetic model for pyrolysis‐based demetallization of heavy oil was established. During pyrolysis, the demetallization of heavy oil is achieved by condensing metal‐rich resins and asphaltenes to coke. The condensation of oil components originally contained in heavy oil differs greatly in reaction behavior, having the activation energy between 167 and 361 kJ/mol. As the pyrolysis progresses, the newly formed heavy components show a condensation behavior close to that of the light components. Limited by high activation energy and low initial fraction, the condensation of asphaltenes to coke and the resulting removal of metals contained in asphaltenes are hindered. Meanwhile, the condensation of light components has a major contribution to coke formation. An increase in reaction temperature accelerates the demetallization, but hardly changes the yield and component distribution of liquid products at the same metal removal rate.

show abstract

“…Among them, vanadium and nickel are a common cause of catalyst degradation and deactivation in hydrotreatment units. For the effective extraction of the metals, the molecular structure of the metal complexes and their location (binding) in the asphaltene-resin aggregates are intensively studied [1][2][3][4][5][6]. These studies appear even more interesting in light of the data proposing vanadyl complexes as a part of quantum computers [7,8] and even as a sensitive probe in biomedical applications [9].…”

Section: Introductionmentioning

confidence: 99%

“…In general, petroleum porphyrins exist in homologous manifolds of several structural classes and can manifest great structural diversity. A series of papers nowadays is devoted to the determination of various vanadyl porphyrins (VP), to application of state-of-the-art massspectroscopic techniques for that purpose as well as to the development of different pathways of the effective vanadyl extraction [1,4,[16][17][18][19][20][21][22][23]. Dickie and Yen were the first to suggest that, having many of the same interactive groups as asphaltenes, petroporphyrins could also play a role in asphaltene self-assembly, adsorption, and phase separation [24].…”

Section: Introductionmentioning

confidence: 99%

“…It is common knowledge that intermolecular interactions, such as hydrogen bonding, dipole−dipole interactions, and π − π stacking, in asphaltenes lead to aggregation into nanoaggregates in the bulk oil phase and the formation of elastic films at organic−aqueous interfaces although the basic asphaltene structure and mechanism of aggregation continue to be debated [2,17,25]. The relationship between petroporphyrins and asphaltenes is largely unexplored [1,4,[26][27][28].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

High-Field (3.4 T) ENDOR Investigation of Asphaltenes in Native Oil and Vanadyl Complexes by Asphaltene Adsorption on Alumina Surface

et al. 2019

View full text Add to dashboard Cite

Vanadyl porphyrin complexes in asphaltenes from heavy (Karmalinskoye) oil and in asphaltene films obtained as a result of adsorption on the surface of aluminum oxide were studied by electron paramagnetic resonance (EPR) and double electron-nuclear resonance (ENDOR) in the W-band frequency range (microwave frequency of 95 GHz, magnetic field of 3.4 T). Mims ENDOR spectra from 1H and 27Al nuclei are observed. ENDOR spectra are different for native oil and asphaltenes from one side and the adsorbed samples from the other side while no significant changes in X- (microwave frequency of 9 GHz) or W-band EPR spectra are found. The results allow supposing that vanadyl porphyrin complexes (at least in the studied asphaltene films) participate in the formation of asphaltene aggregates through the functional groups rather than π−π interactions. The data show the feasibility of the commercial pulsed ENDOR approaches for the investigation of crude oils and their constituents under external influence.

show abstract

Porphyrins in Heavy Petroleums: A Review

Cited by 59 publications

References 130 publications

Comprehensive two-dimensional liquid chromatography with inductively coupled plasma mass spectrometry detection for the characterization of sulfur, vanadium and nickel compounds in petroleum products

Comprehensive two-dimensional liquid chromatography with inductively coupled plasma mass spectrometry detection for the characterization of sulfur, vanadium and nickel compounds in petroleum products

Demetallization of heavy oil through pyrolysis: A reaction kinetics analysis

High-Field (3.4 T) ENDOR Investigation of Asphaltenes in Native Oil and Vanadyl Complexes by Asphaltene Adsorption on Alumina Surface

Contact Info

Product

Resources

About