Asphaltenes Precipitation Onset: Influence of the Addition of a Second Crude Oil or Its Asphaltenes Fractions (C3I and C5I)

Barreira, F.; Reis, Leidiane G.; Nunes, Rita de Cassia P.; Filipakis, Sofia D.; Lucas, Elizabete F.

doi:10.1021/acs.energyfuels.8b01749

Cited by 8 publications

(14 citation statements)

References 40 publications

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“…The asphaltene precipitation onset by titration with n-heptane can be monitored by techniques such as optical microscopy (magnification of 200×) 4,22,23 and near-infrared spectroscopy (NIR). [24][25][26][27][28][29][30] For optical microscopy, aliquots of oil after addition of determined volumes of n-heptane are observed under the microscope until detecting the appearance of asphaltene particles. 4,22,23 In turn, NIR is used to monitor the absorption intensity of the sample during titration with n-heptane: the dilution of the sample leads to a reduction of the absorption intensity, while the appearance of particles causes this intensity to increase.…”

Section: Model Molecules For Evaluating Asphaltene Precipitation Onsementioning

confidence: 99%

“…The oil is considered more stable the greater the volume of n-heptane necessary to cause the asphaltenes to precipitate. [24][25][26][27][28][29][30] Ascertaining the solubility parameter of a crude oil sample by experimental determination of the asphaltene precipitation onset is unreliable when this onset point is hard to detect. This occurs when visualization of the particles by optical microscopy is difficult and the absorption intensity curve in function of n-heptane volume is poorly defined.…”

Section: Model Molecules For Evaluating Asphaltene Precipitation Onsementioning

confidence: 99%

“…This limitation can be overcome by estimating the precipitation onset by mixing the target petroleum with another crude oil that has well-defined precipitation onset, called the standard petroleum. 30,31 Based on this experimental procedure, the solubility parameter of the target oil (δ p ) can be calculated by using equation 2. 17 (2) where δ h , δ p , δ sp are the respective solubility parameters of n-heptane, the target petroleum and the standard petroleum, and ϕ h , ϕ p , ϕ sp are the fractions by volume of n-heptane, target petroleum and standard petroleum in the final mixture at the flocculation point.…”

Section: Model Molecules For Evaluating Asphaltene Precipitation Onsementioning

confidence: 99%

“…In a previous study, 30 a Brazilian crude oil, called APS, was used as the standard to determine the precipitation onset and hence the solubility parameter of two other oils. Since the solubility parameter values obtained are not exactly equal to those determined directly by using the precipitation onset of the target oil sample itself, it is necessary that the standard petroleum always to be the same.…”

Section: Model Molecules For Evaluating Asphaltene Precipitation Onsementioning

confidence: 99%

“…34,[36][37][38][46][47][48][49][50] Molecular simulation has also been employed to improve the relation between the physico-mechanical properties of model molecules and those of real asphaltenes, 34,37,[50][51][52] as well as to shed light on the aggregation and separation of asphaltenes in binary solvent systems. 34,[36][37][38] As already mentioned, in a previous work, 30 we used a petroleum defined as standard (APS) to improve the profile of absorption curve (by NIR) of crude oils called APA and APB in function of the volume of n-heptane titrated. In this study, we synthesized and characterized model molecules to be added to these two crude oils, seeking to find systems whose asphaltenes precipitation onset values are close to those obtained by the addition of APS.…”

Section: Model Molecules For Evaluating Asphaltene Precipitation Onsementioning

confidence: 99%

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Model Molecules for Evaluating Asphaltene Precipitation Onset of Crude Oils

Nunes

Valle

Reis

et al. 2019

J. Braz. Chem. Soc.

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Predicting the compatibility of crude oils from different streams can be done by applying models that use the solubility parameter of the oils. The approximate solubility parameter value of a given crude oil can be calculated by observing the asphaltene precipitation onset caused by titration with n-heptane. For oils whose precipitation onset is not well defined, a small quantity of another petroleum with easily detected onset can be added. It would be ideal to always use the same petroleum for this addition, but this is obviously not possible. The purpose of this study was to replace this petroleum by a synthetic molecule. Therefore, molecules were selected and synthesized to obtain structures containing aromatic ring, aliphatic chain and heteroatom. The molecules were characterized by infrared spectrometry, gas chromatography-mass spectrometry, elemental analysis and gel permeation chromatography. Nitrated cardanol, polycardanol obtained by addition polymerization (PCA) and nitrated PCA presented the desired behavior. However, the concentration of the molecule in toluene needs to be adjusted in function of the characteristics of the petroleum. For a particular crude oil, when model molecule present solubility in a wider solubility parameter range, lower concentration will require to identify the precipitation onset of that oil.

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Section: Model Molecules For Evaluating Asphaltene Precipitation Onsementioning

confidence: 99%

Section: Model Molecules For Evaluating Asphaltene Precipitation Onsementioning

confidence: 99%

Section: Model Molecules For Evaluating Asphaltene Precipitation Onsementioning

confidence: 99%

Section: Model Molecules For Evaluating Asphaltene Precipitation Onsementioning

confidence: 99%

Section: Model Molecules For Evaluating Asphaltene Precipitation Onsementioning

confidence: 99%

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Model Molecules for Evaluating Asphaltene Precipitation Onset of Crude Oils

Nunes

Valle

Reis

et al. 2019

J. Braz. Chem. Soc.

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Compatibility of Crude Oil Blends─Processing Issues Related to Asphaltene Precipitation, Methods of Instability Prediction─A Review

Bambinek

Przyjazny

Boczkaj

2022

Ind. Eng. Chem. Res.

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Processing crude oil of variable composition, especially due to the need to process crude oil blends obtained from various sources, presents a tremendous process challenge. This is mainly due to the destabilization of the colloidal system manifested mostly by the precipitation of the asphaltene fraction. The precipitation of asphaltenes from crude oil is a serious problem during extraction, transport, and processing. In the latter case, engineers and scientists have spent a lot of time determining what mechanisms are conducive to the occurrence of this phenomenon. On the one hand, there was a scientific curiosity about the principles of the nanoworld (nanoscale) of asphaltene molecules that determine their stability, and on the other hand, the willingness of process engineers in refineries to maintain the equipment in the best condition and maximize plant profits. Over the years, many methods have been developed to assess the stability of asphaltenes in crude oils and their blends, starting with methodologies based on the separation of a complex mixture into basic groups of compounds with similar properties (SARA) to sophisticated numerical models on an increasingly better understanding of interactions between molecules under changing conditions. In the former case, the basic instruments available in every laboratory are used whereas in the latter case technically advanced measurement systems capable of reproducing the real conditions of crude oil processing are employed. This paper reviews the methods of determining the stability of crude oils and their blends along with a critical assessment of their effectiveness.

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