Are vanadyl porphyrins products of asphaltene/kerogen thermal breakdown?

Premović, Pavle; Jovanović, Ljubiša S.

doi:10.1016/s0016-2361(96)00201-3

Cited by 9 publications

(2 citation statements)

References 16 publications

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“…Mo and V are found in nitrogenase 3. Metalloporphyrins have also been found in fossil fuels: V porphyrins in kerogens,11 and in heavy petroleum,12 V and Ni porphyrins in crude oils 13–18. Metalloporphyrins containing V, Ga and Fe,19,, 20 as well as Mo and Ni,21 have been observed in coals and Ga porphyrins in coal extracts 22.…”

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Identification of organically associated trace elements in wood and coal by inductively coupled plasma mass spectrometry

Richaud

Lázaro

Lachas

et al. 2000

Rapid Commun. Mass Spectrom.

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1-Methyl-2-pyrrolidinone (NMP) was used to extract samples of wood (forest residue) and coal; the extracts were analysed by inductively coupled plasma mass spectrometry (ICP-MS) using two different sample preparation methods, in order to identify trace elements associated with the organic part of the samples. A sample of fly ash was similarly extracted and analysed in order to assess the behaviour of the mineral matter contained within the wood and coal samples. 32% of the biomass was extracted at the higher temperature and 12% at room temperature while only 12% of the coal was extracted at the higher temperature and 3% at room temperature. Less than 2% of the ash dissolved at the higher temperature. Size exclusion chromatograms of the extracts indicated the presence of significant amounts of large molecular mass materials (>1000 mu) in the biomass and coal extracts but not in the ash extract. Trace element analyses were carried out using ICP-MS on the acid digests prepared by 'wet ashing' and microwave extraction. Sixteen elements (As, Ba, Be, Cd, Co, Cr, Cu, Ga, Mn, Mo, Ni, Pb, Sb, Se, V and Zn) were quantified, in the samples before extraction, in the extracts and in the residues. Concentrations of trace elements in the original biomass sample were lower than in the coal sample while the concentrations in the ash sample were the highest. The major trace elements in the NMP extracts were Ba, Cu, Mn and Zn from the forest residue; Ba, Cu, Mn, Pb and Zn from the coal; Cu and Zn from the ash. These elements are believed to be associated with the organic extracts from the forest residue and coal, and also from the ash. Be and Sb were not quantified in the extracts because they were present at too low concentrations; up to 40% of Mn was extracted from the biomass sample at 202 degrees C, while Se was totally extracted from the ash sample. For the forest residue, approximately 7% (at room temperature) and 45% (at 202 degrees C) of the total trace elements studied were in the extract; for the coal, approximately 8% (at room temperature) and 23% (at 202 degrees C) were in the extract. For the ash, only 1.4% of the trace elements were extracted at 202 degrees C, comprising 25% of Cd but less than 1% of Pb.

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confidence: 99%

Identification of organically associated trace elements in wood and coal by inductively coupled plasma mass spectrometry

Richaud

Lázaro

Lachas

et al. 2000

Rapid Commun. Mass Spectrom.

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“…In this work, we used a solution in which this transition occurs at low temperatures in order to completely exclude the possible chemical reactions involving VOOEP. However, it must be noted since VOOEP is thermally stable enough, 76 the technique can be successfully applied in a wide temperature range, including elevated temperatures, up to ∼200 °C and even more if the ODS is in an inert atmosphere. Accordingly, if real OSD is not too viscous, then our approach can be successfully applied without dilution.…”

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Resin–Paraffin Aggregation Processes in Waxy Oil Revealed by Vanadyl Porphyrin Spin Probe

2023

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The work demonstrates the great potential of using a vanadyl porphyrin probe to study resin−paraffin aggregation processes in oils. The dynamics and polarity of the local environment of vanadyl octaethylporphine (VOOEP), used as a spin probe, specially introduced into oil with a high content of paraffins and resins, have been studied. It has been found that VOOEP does not enter into paraffin crystallites even at temperatures 25 K below the wax appearance temperature but forms aggregates composed of resin molecules that can be adsorbed onto the surface of paraffins. The proposed approach to the precise simulation of experimental ESR spectra based on the Monte Carlo method in the temperature range in which partial averaging of anisotropic interactions is observed showed that as the temperature decreases from 320 to 200 K, the fraction of aggregates that capture the spin probe increases from 10 to 80%. It has been found that the incorporation of VOOEP into the aggregates is accompanied by an increase in the polarity of the local environment of the spin probe, which is consistent with the proposed mechanism of resin−paraffin aggregation processes in waxy oils.

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Extraction of vanadyl porphyrins in crude oil by inclusion dispersive liquid–liquid microextraction and nano-baskets of calixarene

Bahram

Pourabdollah

2012

J Incl Phenom Macrocycl Chem

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Are vanadyl porphyrins products of asphaltene/kerogen thermal breakdown?

Cited by 9 publications

References 16 publications

Identification of organically associated trace elements in wood and coal by inductively coupled plasma mass spectrometry

Identification of organically associated trace elements in wood and coal by inductively coupled plasma mass spectrometry

Resin–Paraffin Aggregation Processes in Waxy Oil Revealed by Vanadyl Porphyrin Spin Probe

Extraction of vanadyl porphyrins in crude oil by inclusion dispersive liquid–liquid microextraction and nano-baskets of calixarene

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