Evaluation of different thermodynamic models in predicting asphaltene precipitation: A comparative study

Daryasafar, Amin; Masoudi, Mohammad; Kord, Shahin; Madani, Mohammad

doi:10.1016/j.fluid.2020.112557

Cited by 23 publications

(21 citation statements)

References 52 publications

(76 reference statements)

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“…Figure shows that emulsions’ stability in 12.5 and 25% toluene in the oil mixture was quite similar in emulsions with 0.25% w/v gilsonite. Figure indicates that the emulsion with 25% toluene in the oil mixture is even more stable than the emulsion with 12.5% toluene and 1% gilsonite, which contradicts the common assumption that higher precipitation always parallels the formation of a more stable emulsion. − Figure shows that the higher the toluene, the less the asphaltene precipitation, and the expectation was to witness higher emulsion stability with lower toluene in the oil mixture. The experimental results of the stability tests refute this hypothesis.…”

Section: Resultsmentioning

confidence: 81%

“…Overall, the consensus is that the crude blend’s increased aromaticity lowers the emulsion stability, and the kinetic stability is often explained through a thermodynamical lens. − The colloidal modeling approach states that the asphaltenes and resins form aggregates, and the aggregates clump together, establishing micelles. These micelles cover the droplets’ interfacial area and stabilize the emulsions by steric hindrance primarily .…”

Section: Introductionmentioning

confidence: 99%

“…Figure24. droplet diameter variation in emulsions with the varied toluene fraction in the oil blend.…”

mentioning

confidence: 99%

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Role of Asphaltene in Stability of Water-in-Oil Model Emulsions: The Effects of Oil Composition and Size of the Aggregates and Droplets

Velayati

Nouri

2021

Energy Fuels

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Water-in-oil (W/O) emulsions are the most common type of emulsions handled in petroleum processes. It is thought that the field emulsions are primarily stabilized by asphaltene–resin micelles, and several research studies have examined the stability mechanisms of asphaltene in crude emulsions. However, there are still plenty of research gaps and unanswered questions in this area due to the complexity of the problem and difficulty of access and crude emulsion processing. These challenges can be addressed by investigating the effect of asphaltene on model emulsions’ kinetic stability. This study introduces a model W/O emulsion prepared by a new stabilizer (gilsonite) that contains asphaltenes and resins in combination with a non-ionic surfactant (Span 83). The colloidal characterization of the asphaltene aggregates in the mineral oil and oil blend of toluene and mineral oil was carried out. The size of the asphaltene aggregates in the mineral oil was found to increase with the added gilsonite concentration because of asphaltene precipitation and the process of smaller aggregates clumping together, forming flocs. Gilsonite was also found to precipitate and stabilize the W/O emulsions with the mineral oil as the external phase where the asphaltene precipitation was the most severe. The emulsions’ least kinetic stability was measured when toluene was added in the oil blend (50% volume fraction), where 100% water phase separation was observed with 0.25% gilsonite concentration. However, the dilute emulsion (10% water content in the emulsion) samples with 25% toluene revealed higher stability in terms of water phase separation than the case with 12.5% toluene with 20.83% less water separation in a 3 day storage period. This observation contradicts the expected outcome in a thermodynamic perspective where the W/O emulsion stability is thought to be merely dependent on asphaltene precipitation. The dilute emulsion with 12.5% toluene contained asphaltene aggregates larger than the emulsion droplets, which cannot contribute to the stability process. The ratio of the mean aggregate size to the mean droplet size was 133% larger for the dilute emulsion with a smaller fraction of toluene in the oil blend for this case. Therefore, the aggregates’ size to droplet size misalignment resulted in less stability for this emulsion than for the emulsion with higher aromaticity of the oil blend despite the very high precipitation rate. This paper presents observations of the effects of the asphaltene precipitation rate, size of the aggregates, and size distribution of the emulsion droplets on the model W/O emulsions’ stability. The significance of the results is in revealing the importance of integrating the thermodynamical and colloidal viewpoints to describe the role of asphaltene in stabilizing emulsions. This approach leads to the conclusion that besides asphaltene precipitation, the aggregate size distribution in relation to the size of the emulsion droplets is a critical factor in stabilizing the emulsions. Results presented in thi...

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Section: Resultsmentioning

confidence: 81%

Section: Introductionmentioning

confidence: 99%

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Role of Asphaltene in Stability of Water-in-Oil Model Emulsions: The Effects of Oil Composition and Size of the Aggregates and Droplets

Velayati

Nouri

2021

Energy Fuels

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“…This equation is a combination of the classical simple SRK equation with an advanced association term, which is Wertheim’s first-order thermodynamic perturbation theory (TPT-1). , The SRK term considers the physical interaction, and the advanced term accounts for the association. Performance of this EoS was acceptable in different applications in the petroleum industry, such as predicting asphaltene precipitation in natural depletion, − gas injection, − in situ oil upgrading, liquid–liquid equilibrium (LLE) modeling in the solvent-assisted bitumen recovery method, , and calculating the solvent/bitumen mixture viscosity in expanding solvent SAGD …”

Section: Introductionmentioning

confidence: 99%

Vapor–Liquid–Liquid Equilibrium Modeling of Water/Bitumen/Solvent (C₁, C₂, C₃, and n-C₄) Mixtures Using a Cubic-Plus-Association Equation of State

Abdi

Zirrahi

2022

Ind. Eng. Chem. Res.

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Multiphase equilibrium calculations are important in primary and enhanced oil recovery production mechanisms such as natural depletion, gas injection, and steam injection. Predicting the physical properties of phases under different conditions is necessary for designing optimum recovery techniques. In this work, we report a cubic-plus-association equation of state (CPA EoS) parameterization of vapor−liquid−liquid equilibrium (VLLE) of water/bitumen/solvent (C 1 , C 2 , C 3 , and n-C 4 ) systems. In this approach, first, the unknown parameters of the EoS are tuned versus the solvent mole fraction in the bitumen-rich phase and saturated bitumen density data. Next, the binary interaction parameters (BIPs) between bitumen and hydrocarbons (C 1 , C 2 , C 3 , and n-C 4 ) and nonhydrocarbon (CO 2 and N 2 ) solvents are adjusted versus experimental data. The absolute average relative deviation (AARD) values for solubility of

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“…The appropriate models provide the development of a quantitative description of the experimental data and can predict the phase behavior of simple and complex solutions. − However, there is not a universally valid model to forecast the phase behavior of biological solutions. Several empirical equations for the solvent activity coefficient in the binary aqueous urea solutions have been proposed in the literature. ,, Recently, Sadeghi et al used the PC-SAFT equation of state for the modeling of mean ionic activity coefficients and osmotic coefficients at 300.15 K in aqueous electrolyte solutions containing urea of different concentrations …”

Section: Introductionmentioning

confidence: 99%

Vapor–Liquid Equilibrium of Aqueous Urea Solution from Dynamic Vapor Sorption Measurements at 283.15–343.15 K

Shahebrahimi

Fazlali

2020

J. Chem. Eng. Data

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Urea solution as a biopolymer denaturing agent and source of nitrogen fertilizer has a key role in some industries, and it seems necessary to study the phase behavior of this system. This work aims to investigate the vapor–liquid equilibria (VLE) of aqueous urea solutions over a wide range of concentrations and temperatures. For this purpose, water activity measurements were performed for the aqueous urea solution using the dynamic vapor sorption (DVS) technique at 283.15–343.15 K in the various urea concentrations. The results showed good agreement between obtained data using DVS and the isopiestic technique at 298.15 K. The conductivity value of the urea solution at 298.15 K revealed that this system is a very weak electrolyte solution. Thereby, a combination of Pitzer’s extension of the Debye–Huckel function (PDH) to cover the ion interaction and some local composition models including Wilson, nonrandom two-liquid (NRTL), nonrandom factor (NRF), modified Wilson-NRF, and NRTL-NRF to point to physical interaction was considered to correlate the experimental activity data. It was revealed that increasing the temperature led to increasing the accuracy of NRTL-NRF and NRF models and other models can correlate the experimental data at any temperature in this range well.

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Evaluation of different thermodynamic models in predicting asphaltene precipitation: A comparative study

Cited by 23 publications

References 52 publications

Role of Asphaltene in Stability of Water-in-Oil Model Emulsions: The Effects of Oil Composition and Size of the Aggregates and Droplets

Role of Asphaltene in Stability of Water-in-Oil Model Emulsions: The Effects of Oil Composition and Size of the Aggregates and Droplets

Vapor–Liquid–Liquid Equilibrium Modeling of Water/Bitumen/Solvent (C₁, C₂, C₃, and n-C₄) Mixtures Using a Cubic-Plus-Association Equation of State

Vapor–Liquid Equilibrium of Aqueous Urea Solution from Dynamic Vapor Sorption Measurements at 283.15–343.15 K

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Evaluation of different thermodynamic models in predicting asphaltene precipitation: A comparative study

Cited by 23 publications

References 52 publications

Role of Asphaltene in Stability of Water-in-Oil Model Emulsions: The Effects of Oil Composition and Size of the Aggregates and Droplets

Role of Asphaltene in Stability of Water-in-Oil Model Emulsions: The Effects of Oil Composition and Size of the Aggregates and Droplets

Vapor–Liquid–Liquid Equilibrium Modeling of Water/Bitumen/Solvent (C1, C2, C3, and n-C4) Mixtures Using a Cubic-Plus-Association Equation of State

Vapor–Liquid Equilibrium of Aqueous Urea Solution from Dynamic Vapor Sorption Measurements at 283.15–343.15 K

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Vapor–Liquid–Liquid Equilibrium Modeling of Water/Bitumen/Solvent (C₁, C₂, C₃, and n-C₄) Mixtures Using a Cubic-Plus-Association Equation of State