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On the effect of temperature on precipitation and aggregation of asphaltenes in light live oils

Mohammadi, S ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1002/cjce.22555
  3. Publisher: Wiley-Liss Inc
  4. Abstract:
  5. Asphaltene precipitation and deposition is a serious issue in all facets of petroleum production and processing. Despite the numerous experimental efforts concerning asphaltenes, the effect of temperature on asphaltene precipitation and aggregation in live oils remains an elusive and controversial subject in the available literature. In this work, a series of high pressure-high temperature depressurization experiments were designed to assess the effect of temperature on asphaltene precipitation and aggregation in light live oils. Asphaltene related experiments were performed using a high pressure microscope and high pressure-high temperature filtration setup on a light live oil with a low asphaltene content and a high potential of asphaltene formation. The results of the experiments were interpreted in terms of asphaltene onset pressure, size distribution and average diameter of the aggregates, fractal dimension of the asphaltene aggregates, and the amount of precipitated asphaltene. It was found that the depressurization process at higher temperatures resulted in higher asphaltene onset pressure or earlier formation of asphaltenes. Visualization experiments showed that asphaltene aggregates in light live oil are pressure-temperature fractal structures. The depressurization process at lower temperatures led to the formation of highly porous and loose aggregate structures with relatively low fractal dimensions. As the temperature of the depressurization process decreases, the mechanism of asphaltene aggregation changes gradually from reaction-limited aggregation to diffusion-limited aggregation. This research reveals that temperature has crucial effects on the asphaltene aggregation process in light live oils at elevated pressures, which is of great importance for asphaltene handling and separation
  6. Keywords:
  7. Agglomeration ; Aggregates ; Fractal dimension ; Fractals ; High pressure effects ; Temperature ; Asphaltene aggregation ; Asphaltene onset pressures ; Asphaltene precipitation ; Diffusion limited aggregation ; Experimental ; High pressure high temperature ; Light oil ; Reaction limited aggregations ; Asphaltenes
  8. Source: Canadian Journal of Chemical Engineering ; Volume 94, Issue 9 , 2016 , Pages 1820-1829 ; 00084034 (ISSN)
  9. URL: http://onlinelibrary.wiley.com/doi/10.1002/cjce.22555/full