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Coalescence of Water Droplets in Crude Oil Emulsions: Analytical Solution
Author(s) -
Bresciani A. E.,
Alves R. M. B.,
Nascimento C. A. O.
Publication year - 2010
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.200900234
Subject(s) - coalescence (physics) , emulsion , oil refinery , oil droplet , crude oil , electric field , volume of fluid method , bubble , petroleum , petroleum engineering , volume (thermodynamics) , chemistry , materials science , mechanics , thermodynamics , engineering , breakup , physics , organic chemistry , quantum mechanics , astrobiology , biochemistry
In petroleum refineries, water is used in desalting units to remove the salt contained in crude oil. Typically, 7 % of the volume of hot crude oil is water, forming a water‐and‐oil emulsion. The emulsion flows between two electrodes and is subjected to an electric field. The electrical forces promote the coalescence of small droplets of water dispersed in crude oil, and these form bigger droplets. This paper calculates the forces acting on the droplets, highlighting particularly the mechanisms proposed for droplet–droplet coalescence under the influence of an applied electric field. Moreover, a model is developed in order to calculate the displacement speed of the droplets and the time between droplet collisions. Thus, it is possible to simulate and optimize the process by changing the operational variables (temperature, electrical field, and water quantity). The main advantage of this study is to show that it is feasible to increase the volume of water recycled in desalting processes, thus reducing the use of freshwater and the generation of liquid effluents in refineries.