Fatty acid-asphaltene interactions at oil/water interface

Wang, Xi; Pensini, Erica; Liang, Yin; Xu, Zhenghe; Chandra, Manish; Andersen, Simon Ivar; Abdallah, Wael; Buiting, Jan

doi:10.1016/j.colsurfa.2016.10.029

Cited by 39 publications

(19 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, some of the surface-active species existing in crude oil are known to stabilize water-in-oil emulsions, which causes further problems in recovery operations . Despite the extensive investigations on the processes occurring at the oil/water interface, which have been conducted over the last five decades, − the mechanistic background for interfacial phenomena, especially the time-resolved decay of interfacial tension for crude oil–water mixtures, is not yet understood in detail. ,,, One of the reasons for this is the complexity of crude oil compositions. Interfacial tension variation is due to a combination of polar (acid–base) and nonpolar (Lifshitz-van der Waals) forces .…”

Section: Introductionmentioning

confidence: 99%

“…Recently, we have shown by gas chromatography mass spectrometry (GC/MS) that a large range of homologous carboxylic acids indeed deposit in abundance at the crude oil–water interface . Examination of Langmuir films of asphaltenes and carboxylic acids indicates a specific interaction between the acid and the asphaltenes, leading to an apparent softening of the interfacial film …”

Section: Introductionmentioning

confidence: 99%

“…20 Examination of Langmuir films of asphaltenes and carboxylic acids indicates a specific interaction between the acid and the asphaltenes, leading to an apparent softening of the interfacial film. 21 Carboxylic acids are well-known surface-active species in nature. They adsorb at the oil−water interface and can form regular organized film structures.…”

Section: ■ Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Dynamic Asphaltene-Stearic Acid Competition at the Oil–Water Interface

et al. 2018

Self Cite

View full text Add to dashboard Cite

Interfacial tension (IFT) is one of the major parameters which govern the fluid flow in oil production and recovery. This paper investigates the interfacial activity of different natural surfactants found in crude oil. The main objective was to better understand the competition between carboxylic acids and asphaltenes on toluene/water interfaces. Dynamic IFT was measured for water-in-oil pendant drops contrary to most studies using oil-in-water drops. Stearic acid (SA) was used as model compound for surface-active carboxylic acids in crude. The influence of concentration of these species on dynamic IFT between model oil and deionized water was examined. The acid concentrations were of realistic values (total acid number 0.1 to 2 mg KOH/g oil) while asphaltene concentrations were low and set between 10 and 100 ppm. In mixtures, the initial surface pressure was entirely determined by the SA content while asphaltenes showed a slow initial diffusion to the interface followed by increased adsorption at longer times. The final surface pressure was higher for asphaltenes compared to SA, but for binaries, the final surface pressure was always lower than the sum of the individuals. At high SA concentration, surface pressures of mixtures were dominated entirely by the SA, although, Langmuir isotherm analysis shows that asphaltenes bind to the interface 200-250 times stronger than SA. The surface area/molecule for both SA and asphaltenes were found to be larger than the values reported in recent literature. Various approaches to dynamic surface adsorption were tested, showing that apparent diffusivity of asphaltenes is very low, in agreement with other works. Hence, the adsorption is apparently under barrier control. A possible hypothesis is that at the initial phase of the experiment and at lower concentration of asphaltenes, the interface is occupied by stearic acid molecules forming a dense layer of hydrocarbon chains that may repel the asphaltenes.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Dynamic Asphaltene-Stearic Acid Competition at the Oil–Water Interface

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…The experimental compression isotherm of lecithin−saponin mixtures fell in between the isotherms measured with the individual components, in either DI water or NaCl solutions. This result can be attributed to either the coadsorption of lecithin and saponin at the toluene−water interface (as individual components) 70 or to the formation of lecithin− saponin complexes. 71 In addition to differences in the maximum pressure achieved, the species in water also affected the shape of the compression isotherms.…”

Section: T H Imentioning

confidence: 99%

Zein-Bonded Graphene and Biosurfactants Enable the Electrokinetic Clean-Up of Hydrocarbons

et al. 2021

Self Cite

View full text Add to dashboard Cite

Nonaqueous phase liquids (NAPL, e.g., hydrocarbons and chlorinated compounds) are common groundwater pollutants. Electrokinetic remediation of NAPLs uses electric fields to draw them toward electrodes and remove them from groundwater. The treatment requires NAPL mobility. Emulsification increases mobility, but at a risk for downstream receptors. We propose using alkaline aqueous solutions of zein and graphene nanoparticles (GNP) to form conductive materials, which could also act as barriers to control NAPL migration. Alkaline zein−GNP solutions can be injected in the polluted soil and solidified by neutralizing the pH (e.g., with glacial acetic acid, GAA). Shear rheology experiments showed that zein−GNP composites were cohesive, and voltammetry showed that GNP increased electrical conductivity of zein-based materials by 3.5 times. Gas chromatography−mass spectroscopy (GC−MS) demonstrated that the electrokinetic treatment of model sandy aquifers yielded >60% and ∼47% removal of emulsified toluene in freshwater and in salt solutions, respectively (with 30 min treatment using a 10 V differential voltage between a zein−GNP and an aluminum electrode. NaCl was used as model salt contaminant. The conductivity of surfactant solutions was lower in saline water than in freshwater, explaining differences in toluene removal. Toluene−water emulsions were stabilized using the natural surfactants lecithin and saponin. These surfactants acted synergistically in stabilizing emulsions in either freshwater or salt solutions. Lecithin and saponin likely interacted at toluene−water interfaces, as indicated by the morphology, interfacial tension and compressional rigidity of toluene−water interfaces with both components (relative to interfaces of either lecithin or saponin alone). The compressional behavior of interfacial films was well-described by the Marczak model. Electrokinetic treatment of saturated model sandy aquifers also decreased the turbidity of emulsions of water and either tricholoroethylene (TCE, by ∼41%) or diesel (by ∼75%), in the presence of a bacterial biosurfactant. This decrease was used as semiquantitative indicator of NAPL removal from water.

show abstract

“…A general mechanism is that the basic nitrogen-containing functional groups in asphaltenes interact with the naphthenic acids, leading to the formation of naphthenic acid-asphaltene complexes which have stronger capabilities of stabilizing the oil/water interface [31]. More recent studies have suggested that organic acids could soften the rigid asphaltene film on the oil/water interface and make the emulsion more stable [34].…”

Section: Organic Acidsmentioning

confidence: 99%

Interfacial Chemistry in Steam-Based Thermal Recovery of Oil Sands Bitumen with Emphasis on Steam-Assisted Gravity Drainage and the Role of Chemical Additives

Taylor

2018

Colloids and Interfaces

View full text Add to dashboard Cite

In this article, the importance of colloids and interfaces in thermal heavy oil or bitumen extraction methods is reviewed, with particular relevance to oil sands. It begins with a brief introduction to the chemical composition and surface chemistry of oil sands, as well as steam-based thermal recovery methods. This is followed by the specific consideration of steam-assisted gravity drainage (SAGD) from the perspective of the interfacial chemistry involved and factors responsible for the displacement of bitumen from reservoir mineral surfaces. Finally, the roles of the different chemical additives proposed to improve thermal recovery are considered in terms of their contributions to recovery mechanisms from interfacial and colloidal perspectives. Where appropriate, unpublished results from the author's laboratory have been used to illustrate the discussions.

show abstract

Fatty acid-asphaltene interactions at oil/water interface

Cited by 39 publications

References 48 publications

Dynamic Asphaltene-Stearic Acid Competition at the Oil–Water Interface

Dynamic Asphaltene-Stearic Acid Competition at the Oil–Water Interface

Zein-Bonded Graphene and Biosurfactants Enable the Electrokinetic Clean-Up of Hydrocarbons

Interfacial Chemistry in Steam-Based Thermal Recovery of Oil Sands Bitumen with Emphasis on Steam-Assisted Gravity Drainage and the Role of Chemical Additives

Contact Info

Product

Resources

About