Quantifying the role of ultrasonic wave radiation on kinetics of asphaltene aggregation in a toluene-pentane mixture

I. Najafi, S. M R Mousavi, M. H. Ghazanfari, C. Ghotbi, A. Ramazani, R. Kharrat, Mahmood Amani

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Recently, ultrasonic wave technology has received much attention as a method for removal of asphaltene deposits from the near wellbore region. However, very little is known about another feature of this technology on the kinetics of asphaltene molecules aggregation. In this work, the kinetics of asphaltene flocculation in several crude oil samples exposed to ultrasonic waves for different time intervals is studied by confocal microscopy. The colloidal structural evolutions of flocks are described by analysis of size distribution of flocculated asphaltene particles. The results show that for the first 90 min of flocculation time, the size of aggregates increases rapidly, and a reaction-limited aggregation model matches well with the experimental data for all samples. But, after 90 min, a reduction in aggregate size of sonicated samples is observed, whereas the aggregate size of nonsonicated oil samples increases in close agreement with the diffusion-limited aggregation model. It has been found that asphaltene flocculation of sonicated samples cannot obey classic Derjaguin-Ladau-Verwey-Overbeek (DLVO) theory of colloidal dispersions due to partial reversibility of flocculation. An optimum value for ultrasonic radiation time, at which the viscosity and flocculation rate of asphaltenic crude oils reduce to a minimum, is found to be close to 10 min for Sarvak crude oil. The results of this study illustrate two different behaviors associated with asphaltene aggregation in the case of sonicated oil samples.

Original languageEnglish
Pages (from-to)966-974
Number of pages9
JournalPetroleum Science and Technology
Volume29
Issue number9
DOIs
Publication statusPublished - Jan 2011
Externally publishedYes

Fingerprint

asphaltene
Ultrasonic waves
Toluene
Flocculation
toluene
flocculation
Agglomeration
Radiation
kinetics
Kinetics
Petroleum
Crude oil
crude oil
aggregate size
Oils
Confocal microscopy
Dispersions
oil
Deposits
Ultrasonics

Keywords

  • asphaltene aggregation kinetics
  • asphaltene flocks size distribution
  • confocal microscopy
  • DLVO colloidal model
  • flocculation time
  • ultrasonic wave technology

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Fuel Technology
  • Geotechnical Engineering and Engineering Geology
  • Energy Engineering and Power Technology

Cite this

Quantifying the role of ultrasonic wave radiation on kinetics of asphaltene aggregation in a toluene-pentane mixture. / Najafi, I.; Mousavi, S. M R; Ghazanfari, M. H.; Ghotbi, C.; Ramazani, A.; Kharrat, R.; Amani, Mahmood.

In: Petroleum Science and Technology, Vol. 29, No. 9, 01.2011, p. 966-974.

Research output: Contribution to journalArticle

Najafi, I. ; Mousavi, S. M R ; Ghazanfari, M. H. ; Ghotbi, C. ; Ramazani, A. ; Kharrat, R. ; Amani, Mahmood. / Quantifying the role of ultrasonic wave radiation on kinetics of asphaltene aggregation in a toluene-pentane mixture. In: Petroleum Science and Technology. 2011 ; Vol. 29, No. 9. pp. 966-974.
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