Effects of Short-Chain n-Alcohols on the Properties of Asphaltenes at Toluene/Air and Toluene/Water Interfaces

Martins, Raphael G.; Martins, Lilian S.; Santos, Ronaldo Gonçalves dos

doi:10.3390/colloids2020013

Cited by 12 publications

(10 citation statements)

References 21 publications

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“…For the heptol50–water system, the interfacial tension in the absence of asphaltene is around 40 mN/m. For both systems (toluene–water as well as heptol50–water), the interfacial tension shows a decreasing trend with increasing asphaltene concentration and becomes almost negligible at around 3000 ppm concentration for the toluene–water system, which matches with the literature . The interfacial tension for the heptol50–water system decreases much faster than for the toluene–water system and crosses it at around 500 ppm concentration before finally becoming stable at around 2000 ppm.…”

Section: Resultssupporting

confidence: 86%

Effect of Asphaltenes on the Kinetics of Methane Hydrate Formation and Dissociation in Oil-in-Water Dispersion Systems Containing Light Saturated and Aromatic Hydrocarbons

2021

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Proper understanding of the interaction of individual components of crude oil with hydrate formation and dissociation is essential to design an effective mitigation strategy for hydrate blockage, especially in offshore flowlines. In this study, various isothermal methane hydrate formation and dissociation kinetics experiments have been carried out in oil-in-water dispersion systems to understand the effect of liquid hydrocarbons (such as n-heptane and toluene) and asphaltenes with varying concentrations at 8 MPa and 275.15 K. To correlate the results obtained from the kinetics experiments, solubility tests and interfacial tension measurements have also been carried out. It was observed that aromatic hydrocarbons (e.g., toluene) in the system led to less dissolution of methane gas as compared to alkanes (e.g., n-heptane). This, along with the more developed oil− water interface due to the lower density difference with water, made the system more vulnerable to hydrate formation, and it displayed secondary hydrate induction. The presence of asphaltenes in the oil−water system showed higher gas consumption during hydrate formation at lower concentrations, possibly due to flocculated asphaltene molecules at the oil−water interface acting as nucleation sites for hydrate formation. As the concentration of asphaltene increases, the growth of hydrate crystals is found to be limited, as more asphaltene molecules tend to restrict the gas diffusion toward the water phase, controlling the growth kinetics during hydrate formation. The hydrate dissociation experiments suggest that the presence of flocculated asphaltenes in the system has delayed the dissociation of methane hydrate crystals for some time. The findings of this study will help gain an insight into the interaction of asphaltene, alkanes, and aromatics on the kinetics of methane hydrate formation and dissociation suitable for flow assurance applications.

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Section: Resultssupporting

confidence: 86%

Effect of Asphaltenes on the Kinetics of Methane Hydrate Formation and Dissociation in Oil-in-Water Dispersion Systems Containing Light Saturated and Aromatic Hydrocarbons

2021

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“…Asphaltenes are a solubility family of compounds with the proven interfacial activity present as indigenous components of crude oil. − The different interactions at interfaces are responsible for a variety of phenomena that strongly influence crude oil production − and transport. , The uncertainty brought by the lack of consensus on the molecular weight of asphaltenes and their dominating structures − hinders the development of comprehensive interfacial thermodynamic models for their adequate study.…”

Section: Introductionmentioning

confidence: 99%

Deviation from Equilibrium Thermodynamics of an Asphaltene Model Compound during Compression–Expansion Experiments at Fluid–Fluid Interfaces

et al. 2021

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Asphaltenes play a crucial role in crude oil behavior, and model compounds are often used to capture, mimic, and predict certain interfacial properties. In previous works, sorption of an asphaltene model compound (C5PeC11) was studied using surface pressure isotherms, where a deviation from the expected thermodynamic behavior of the interface during decane−water and air−water compression experiments was observed but not explained. In this work, the interfacial behavior of C5PeC11 was assessed at the decane−water and the air−water interfaces using a multiscale approach that includes: compression−expansion experiments on rectangular and radial Langmuir troughs, dynamic interfacial stress relaxation, and fluorescence microscopy imaging. Connections between molecular and microscopic phenomena strongly suggest that the nonthermodynamic response can be explained through a dynamic effect whose origin lies in the predominance of intermolecular forces in C5PeC11 molecules over the mechanical compression force applied. When aggregation begins at the air− water interface, stable structures are formed, and the nonthermodynamic phenomenon is not observed in subsequent compressions. However, at the decane−water interface, the initial aggregation is not consolidated due to the effect of the oil phase on the free energy of the interface allowing the high reproducibility of the dynamic effect in subsequent compression cycles. These results highlight the need to probe interfacial systems at various length scales to adequately separate equilibrium thermodynamics from dynamic responses.

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“…Se ha determinado que, incluso en bajas concentraciones, la molécula de asfaltenos presenta tendencia a agregarse y precipitarse, lo que causa grandes daños en las diferentes etapas del procesamiento del petróleo, como consecuencia de obstrucciones ocasionadas por los depósitos orgánicos que producen (Guzmán et al, 2017;Hasanvand et al, 2018). La formación de depósitos de asfaltenos es un problema de importancia en la producción de petróleo, porque el depósito de asfaltenos perjudica la recuperación y la producción, al producir reducción de la permeabilidad de la roca del yacimiento y disminución del diámetro efectivo de los punzonados en la tubería de producción, lo que restringe el flujo de petróleo (Martins, Martins y Santos, 2018).…”

Section: Introductionunclassified

“…El uso de dispersantes de asfaltenos, genera costos importantes a la industria petrolera, no solo de dinero, sino ambientales, debido a que los mismos están compuestos por compuestos activos y solventes como el tolueno o xileno, que son tóxicos y potenciales contaminantes de suelos y aguas (Alrashidi y Nasr-El-Din, 2017). Debido a lo anterior, se ha investigado el uso de compuestos químicos alternativos, como alcoholes de cadena corta (Martins et al, 2018), metil esteres, terpenos y etil lactato (Elochukwu, Saaid y Pilus, 2014). De igual forma, se han estudiado productos naturales, en particular, aceites vegetales y derivados de ellos como dispersantes de asfaltenos, entre los que se pueden citar, ácidos grasos como el láurico, palmítico y oleico (Alrashidi, Afra y Nasr-El-Din, 2019), los aceites de coco y de andiroba (Alrashidi y Nasr-El-Din, 2017; Marín, 2019), los aceites de nabo, almendra amarga, sésamo, manzanilla, jengibre, avellana, oliva y romero (Mardani, Mokhtari y Soltani, 2018), aceite de Jatropha curcas (Marín, Marcano y Febres, 2016).…”

Section: Introductionunclassified

Análisis comparativo de la eficiencia estabilizadora de asfaltenos del aceite de cáscara de Anacardium occidentale y productos comerciales

Tocuyo

Velásquez

2020

Enfoque UTE

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La investigación tuvo como objetivo comparar la eficiencia inhibidora y estabilizante de asfaltenos, en mezclas de aceite de cáscaras de Anacardium occidentale (CNSL) en diésel y productos dispersantes comerciales, para evaluar el aceite como alternativa de tratamiento químico antiasfalténico del petróleo crudo. Se determinó el umbral de floculación por precipitación con n-heptano y el punto de dispersión por adición de xileno, ambos mediante la observación directa de la formación de flóculos de asfaltenos en un microscopio óptico. El diseño experimental utilizado fue factorial, con cuatro variables respuestas (umbral de floculación, actividad inhibidora, índice de inestabilidad y eficiencia de estabilización) y dos factores experimentales (producto y dosis). Se evaluaron cinco productos con CNSL y tres productos comerciales, todos en dosis 2, 4, 6 y 8 µl en 10 ml de una muestra de petróleo crudo mediano. El análisis estadístico se basó en Anova multifactorial y test de diferencia mínima significativa de Fisher (LSD) con α = 0.05. Se obtuvo que los dos factores experimentales influyeron significativamente en las variables respuestas de forma individual y también sus interacciones. Los productos con CNSL fueron más eficientes como inhibidores y los comerciales más eficientes como estabilizadores.

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Effects of Short-Chain n-Alcohols on the Properties of Asphaltenes at Toluene/Air and Toluene/Water Interfaces

Cited by 12 publications

References 21 publications

Effect of Asphaltenes on the Kinetics of Methane Hydrate Formation and Dissociation in Oil-in-Water Dispersion Systems Containing Light Saturated and Aromatic Hydrocarbons

Effect of Asphaltenes on the Kinetics of Methane Hydrate Formation and Dissociation in Oil-in-Water Dispersion Systems Containing Light Saturated and Aromatic Hydrocarbons

Deviation from Equilibrium Thermodynamics of an Asphaltene Model Compound during Compression–Expansion Experiments at Fluid–Fluid Interfaces

Análisis comparativo de la eficiencia estabilizadora de asfaltenos del aceite de cáscara de Anacardium occidentale y productos comerciales

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