Solution behavior of asphaltic residues and deasphalted oil prepared by extraction of heavy oil

Altoé, Rodrigo; Oliveira, Márcia; Lopes, H. E.; Teixeira, C.; Cirilo, Leilane; Lucas, Elizabete F.; González, Gaspar

doi:10.1016/j.colsurfa.2013.12.082

Cited by 12 publications

(14 citation statements)

References 25 publications

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“…The percentage of fraction A-C7I removed from the solution was significantly higher (∼70%) than that of A-C5I. This is coherent with the fact that fraction A-C5I is more stable than C7I due to the wider polarity distribution of its molecules, ,,,, and also because the polymer, with polar character, interacts preferentially with the more polar asphaltene molecules, indicating that the most likely action mechanism was adsorption of the asphaltenes on the polymers.…”

Section: Resultssupporting

confidence: 54%

“…Moreover, asphaltene flocculants can be applied in deasphalting processes, which consist of removing the asphaltenic material from the residues left after producing certain derivatives, such as paraffins or lubricating oils. Another application of these flocculants is to improve heavy crude by reducing the asphaltenic fraction, to raise the market price of the oil. − …”

Section: Introductionmentioning

confidence: 99%

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Flocculation of Asphaltenes by Polymers: Influence of Polymer Solubility Conditions

et al. 2018

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Sulfonated polystyrene has shown flexible action as an asphaltene dispersant/flocculant as a function of the degree of sulfonation and concentration used. In this work, samples of sulfonated polystyrene with different sulfonation degrees were assessed in precipitation assays in model asphaltene systems, with variation of the asphaltene fractions (asphaltenes extracted by n-pentane and n-heptane, C5I and C7I, respectively), asphaltene concentration, polymer concentration, and medium used to dissolve the polymer and asphaltenes. The precipitation tests were carried out with an ultraviolet–visible spectrometer, and the absorbance values were converted into asphaltene concentration values in solution by using calibration curves. The results showed that the concentration of sulfonic groups at which the polymer performs best as an asphaltene flocculant is 10 mol %. The dependence of the polymer’s effect as a flocculant or stabilizer of asphaltenes in function of its hydrophilicity and concentration was confirmed. Moreover, the results indicate there is a strong relationship between the polymer’s solubility in the medium and its flocculant action, which is significantly more effective when the polymer does not have strong affinity for the medium.

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Section: Resultssupporting

confidence: 54%

Section: Introductionmentioning

confidence: 99%

Flocculation of Asphaltenes by Polymers: Influence of Polymer Solubility Conditions

et al. 2018

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“…It is known that the flow of crude oil is influenced by the formation of asphaltenes aggregates (Altoé, et al, 2014), and this influence depends on the size of the particles formed. In this case, the evaluation of the performance of additives to stabilize asphaltenes can produce false negatives, since the additive can present good performance in reducing the size of the asphaltenes aggregates without causing a significant shift in the precipitation onset.…”

Section: Introductionmentioning

confidence: 99%

The influence of chemicals on asphaltenes precipitation: a comparison between atomic force microscopy and near infrared techniques

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Soares

et al. 2017

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Asphaltenes can cause serious problems to petroleum industry. Indication of asphaltenes stability can be obtained by precipitation induced by n-heptane, monitored by near-infrared (NIR). However, this technique does not provide information on the particles sizes. In this study, the precipitation onset of model systems (1wt% asphaltenes in toluene) was monitored by NIR, with and without adding additive. The particles sizes of the same systems were monitored by atomic force microscopy (AFM): Dispersions of asphaltenes in toluene, n-heptane and mixtures of these two solvents were analyzed by AFM. For the pure model system, the size of the asphaltenes aggregates clearly increased in function of rising n-heptane concentration in the solvent mixture, with this increase being much more pronounced for solubility parameter values below that corresponding to the precipitation onset. In the presence of additives, significantly smaller particles were obtained even when the precipitation onset showed only a slight shift.

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“…Their SARA analyses were supplied by Petrobras, using chromatographic analysis (ASTM D5186) 47 and the IP-143/84 method. 48,49 Results of these analyses are listed in Table 1 along with the calculated, SARA-based CII of the COs. The corresponding asphalt-free and resin-free fractions (CO (Asp&Res-free) ) were supplied by Petrobras and were obtained using high pressure fractionation unit.…”

Section: Methodsmentioning

confidence: 99%

Successful Approach to Mimic the Solvent Power of Maltenes Based on SARA Analysis, Solvatochromic and Solubility Parameters

et al. 2018

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We extended the oil compatibility model to the dissolution of asphaltenes (Asps) in maltenes from 10 crude oils (COs). As scales for the power of solvents of interest, vide infra, we used solvatochromic parameters, calculated from the UV–vis spectra of solvatochromic compounds (probes), Hildebrand/Hansen solubility parameters, and the colloidal instability index of COs. As the colors of maltenes or asphaltene-free crude oils CO(Asp‑free) were too dark to permit recording the absorption spectra of the probes, we formulated models for these fractions (MCO(Asp‑free)). They were composed of low molar mass hydrocarbons, namely, cis and trans decalines, isooctane, 1-methylnaphthalene and, as model for resins, benzothiazole/n-octyl-1-naphthoate. We based formulations of these MCO(Asp‑free) on SARA analysis of the COs and elemental analysis of the corresponding resins. We validated MCO(Asp‑free) as models for the corresponding CO(Asp‑free) by showing that the correlation between Hildebrand solubility parameter (δt) of (COs) and δt for MCO(Asp‑free) is linear with a slope close to unity. Regarding Asp dissolution, we show that the correlations between log(dissolved Asp, mass %) and each of the following solvent descriptors is linear: empirical polarity of MCOs(Asp‑free); δt of COs; colloidal instability index of COs. Furthermore, the multiple correlation between log(dissolved Asp, mass %) and other solvatochromic parameters showed that solvent dipolarity and polarizability are important factors for Asp dissolution, in agreement with our previous results on Asp dissolution in pure solvents. The formulation of a model that successfully mimics maltenes is potentially very useful, e.g., in rationalizing the efficiency of certain classes of additives employed for Asp stabilization.

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Solution behavior of asphaltic residues and deasphalted oil prepared by extraction of heavy oil

Cited by 12 publications

References 25 publications

Flocculation of Asphaltenes by Polymers: Influence of Polymer Solubility Conditions

Flocculation of Asphaltenes by Polymers: Influence of Polymer Solubility Conditions

The influence of chemicals on asphaltenes precipitation: a comparison between atomic force microscopy and near infrared techniques

Successful Approach to Mimic the Solvent Power of Maltenes Based on SARA Analysis, Solvatochromic and Solubility Parameters

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