Developing a novel colloidal model for predicting asphaltene precipitation from crude oil by alkane dilution
| Autor: | M. M. Shadman, Mostafa Dehghanizadeh, Amir Hossein Saeedi Dehaghani, Mohammad Hasan Badizad |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Thermodynamics 02 engineering and technology 010402 general chemistry 01 natural sciences Surface tension symbols.namesake Adsorption Materials Chemistry Physical and Theoretical Chemistry Spectroscopy Asphaltene Alkane chemistry.chemical_classification Precipitation (chemistry) 021001 nanoscience & nanotechnology Condensed Matter Physics Atomic and Molecular Physics and Optics 0104 chemical sciences Electronic Optical and Magnetic Materials Gibbs free energy Dilution chemistry Particle-size distribution symbols 0210 nano-technology |
| Zdroj: | Journal of Molecular Liquids. 318:113879 |
| ISSN: | 0167-7322 |
| DOI: | 10.1016/j.molliq.2020.113879 |
| Popis: | This research aims to propose a thermodynamic model for predicting asphaltene precipitation upon diluting a crude oil with a paraffinic solvent. To this end, a thorough mathematical formulation was carried out to derive a novel micellization model based on the associative properties of asphaltenic compounds. It was assumed that asphaltenes exist in the oil both as monomeric molecules and aggregated cores; with stabilization latter by attachment of resin on its periphery. The aggregation equilibrium was established by taking into account asphaltene's lyophobic tendency, heat of resin adsorption, and interfacial tension between micelle and oil media which is the main driving factor contributing to Gibbs free energy of micellization. In this study, the mean diameter of asphaltene aggregates at different dilution ratios was incorporated into the framework of modeling approach, by measuring particle size distribution of asphaltenes at varying n-heptane fractions. The data density of pure asphaltene for an Iranian crude-oil sample was used in calculations. The proposed model favorably predicted the precipitation trend of the crude oil diluted at varying fractions of n-heptane. This model shows that taking into account the size of asphaltene aggregates can significantly improve the prediction accuracy of the micellization model, compared to the simple model, with normalized root-mean-square error of 9.4 and 28.7, respectively. A detailed sensitivity analysis was performed to gain insight into physical implication of the model parameters. |
| Databáze: | OpenAIRE |
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