Flocculation of Asphaltenes by Polymers: Influence of Polymer Solubility Conditions

Abstract

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.

Polarity of Cationic Lignin Polymers: Physicochemical Behavior in Aqueous Solutions and Suspensions

“…[22] In another study, sulfonated polystyrenes with varied sulfonation degrees were produced to precipitate a model asphaltene suspension, and the polymers with greater polarities had better flocculation performance. [23] These studies suggest that the polarities of polymers may directly affect their performance in interacting with other particles in suspensions. In this regard, the impact of lignin-based polymers (with different polarities) on the flocculation of kaolin suspension is unclear, which is the second objective of the current study.…”

Challenges in developing polymer flocculants to improve bitumen quality in non-aqueous extraction processes: an experimental study

“…Hyperbranched functionalized polyethylene (HBfPE) (5% methyl acrylate) was synthesized in our group, as described elsewhere (Botha et al 2017). Polystyrene sulfonate was modified according to the procedure detailed in Mazzeo et al (Mazzeo et al 2018).…”

“…Polymer solubility was determined qualitatively based on cloud point observations at room temperature, at concentrations of 2 mg/mL (Mazzeo et al 2018). Both toluene and cyclohexane were used as solvents to screen the viability of the polymer flocculants.…”

Reduction of asphaltenes adsorbed on kaolinite by polymers based on cardanol

“…Since the asphaltenes adsorbed on fine solids can influence the dewatering process, it would be expected that flocculants for asphaltenes could be used to reduce the amount of asphaltenes adsorbed. In turn, the action of polymers as asphaltenes flocculants has also been observed (Ferreira et al 2015;Palermo and Lucas 2016;Mazzeo et al 2018;Zou et al 2019). Since the aromatic ring of styrene has a great potential to interact with the asphaltenes polyaromatic structure, some studies have been done using styrene in the copolymer structure, for example, with acrylate presenting long hydrocarbon chains or with sulfonated styrene.…”

“…Since the aromatic ring of styrene has a great potential to interact with the asphaltenes polyaromatic structure, some studies have been done using styrene in the copolymer structure, for example, with acrylate presenting long hydrocarbon chains or with sulfonated styrene. Depending on the copolymer composition, it was found that the copolymers can act as a stabilizer or flocculant of asphaltenes (Palermo and Lucas 2016;Mazzeo et al 2018;Zou et al 2019). Polymers based on cardanol, which is a biodegradable waste product from the cashew nut industry and widely available as derived from CNSL (cashew nut shell liquid) (Lopes et al 2008;Mazzetto et al 2012;Ferreira et al 2015;Paula et al 2020;Celia-Silva et al 2020), have also been studied as dispersant and flocculant of asphaltenes.…”