Asphaltenes currently represent one of the most studied fractions of crude oil. This high-polarity fraction has an important impact on the value chain of the petroleum industry as a consequence of precipitation during production operations and coke formation during refining. Typical issues related to asphaltenes are due to changes in the phase equilibria dynamics during those processes. Asphaltene precipitation commonly causes plugging of pipelines and process equipment such as pumps, heat exchangers, or separator tanks. Likewise, during oil refining and upgrading operations, asphaltenes are the primary promoters of petcoke—one of the main by-products of those operations. Understanding the mechanism and kinetics of asphaltenes’ agglomeration, flocculation, and precipitation is vital to estimate the stability of this oil fraction. Determination of the flocculation (onset) point is rather important because this point represents the threshold where asphaltenes are not in solution anymore and irreversibly begin to precipitate. Different <i>ex situ</i> optical techniques have previously been developed to monitor the flocculation behavior. The fundamentals of such techniques are based on the interaction of asphaltenes-containing media (crude oil) with light. Alternatively, due to the asphaltenes‘ high polarity, electrical conductivity approaches have been employed to determine the flocculation point of asphaltenes. Taking conductivity data as a function of asphaltene concentration by EIS, change in the asphaltene aggregate size has been studied. The use of this technique to obtain conductivity data during the determination of the onset point of asphaltene flocculation, however, has not been reported. In this presentation, we will show results on the electrical conductivity of asphaltenes' solutions obtained via EIS as an alternative approach to determining the flocculation point of asphaltenes. More interestingly, outstanding results after coupling EIS with ultrasound (US) pulses show the high potential of this technique as an alternative way of determining asphaltenes' flocculation point.

Following the flocculation of crude oil asphaltenes’ using ultrasound and electrochemical impedance spectroscopy

256th National Meeting (2018)

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