Asphaltene Emulsions

Effect of the Asphaltene Oxidation Process on the Formation of Emulsions of Water in Oil (W/O) Model Solutions

“…It is observed that for the untreated asphaltenes and the asphaltenes oxidized at 373 and 473 K, the amount of W/O emulsion formed increases as the asphaltene concentration increases, i.e., increase in concentration increases the quantity of oil-soluble natural surfactants (NS) leading to a higher percentage of W/O phase. Moreover, oxidation increases water affinity and reduce oil solubility thus promoting NS adsorption at the interface [23,29]. This effect can be explained due to as the relative coverage of asphaltene at the model solution-water interface increases, the interfacial film may behave more elastic than viscous which increases the system stiffness that has been attributed to asphaltenes cross-linking [19,63].…”

“…Asphaltenes are polar and high molecular weight compounds in colloidal dispersion in oil, containing heteroatoms such as N, O, and S. Their location in the molecular structure gives the asphaltenes high polarity and an amphiphilic character, i.e., its structure has different functional groups with polar and nonpolar selectivity [22]. In the emulsions formation, the accumulation of asphaltenes at the water-oil interface forms a rigid film that directly influences the stability of the emulsion and prevents droplet coalescence of the dispersed phase [23,24]. According to Rane et al [25][26][27][28], asphaltenes form a film at the water-oil interface where asphaltene are adsorbed and form a stable multilayer that prevents separation of the immiscible phases.…”

Rheological properties of highly concentrated dense packed layer emulsions (w/o) stabilized by asphaltene

“…Several literature studies report emulsion stabilization properties of asphaltenes. 4,27,28 The studies successfully correlate chemical and physical properties of with the emulsion stability of the respective crude oil.…”

“…The aggregate size depends on temperature, pressure, and nature of the solvent. 4,27,28 Despite frequent formation of stable DPLs during separation processes, there is an absence of fundamental knowledge concerning DPL rheological characteristics. Knowledge of rheological properties of these systems may lead to improved predictions of DPL deformation and break up processes.…”

Studying the Influence of Antifoaming Additives on Crude Oil/Air Interface: Proposal of a New Methodology

“…Some studies have evaluated the asphaltene/air and asphaltene/water interfaces of solutions using the Du Noüy ring (Oliveira et al, 2017), while others have used the BiCone accessory (Fan et al, 2010;Spiecker & Kilpatrick, 2004;Kilpatrick & Spiecker, 2001). However, to the best of our knowledge, no studies have been published involving rheological analysis applied at the crude oil/air interface to investigate the formation of foams.…”