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Optimum Operating Frequency for Electrocoalescence Induced by Pulsed Corona Discharge
Mohcen Shahbaznezhad1, Amir Dehghanghadikolaei2, Hossein Sojoudi2
1Department of Electrical Engineering and Computer Science, The University of Toledo, Toledo, Ohio 43606, United States.
ACS Omega
|December 16, 2020
Summary
This study introduces a novel contactless charge injection method using pulsed direct current (dc) electric fields for efficient oil-water separation. The optimized method improves coalescence effectiveness and energy efficiency in emulsions.
Area of Science:
- Petroleum Engineering
- Chemical Engineering
- Applied Physics
Background:
- Current oil-water separation techniques are energy-intensive, time-consuming, and inefficient.
- Pulsed and nonuniform electric fields offer potential solutions for common separation issues like chain formation and partial coalescence.
Purpose of the Study:
- To investigate the impact of nonuniform and pulsed direct current (dc) electric fields on water droplet coalescence in oil.
- To optimize operating parameters for enhanced effectiveness and energy efficiency in oil-water separation.
Main Methods:
- Utilized a contactless charge injection method via corona discharge.
- Employed high-speed imaging and image processing to analyze droplet interactions and forces (dipole-dipole, electrophoresis, dielectrophoresis).
- Experimentally calibrated and optimized pulsed dc frequencies and pure dc waveforms.
Main Results:
- Demonstrated that pulsed dc and pure dc electric fields significantly impact water droplet coalescence.
- Identified optimal electric field parameters for improved coalescence effectiveness and energy consumption.
- Proposed specific electric field strategies for concentrated and dispersed emulsions.
Conclusions:
- Pulsed dc electric fields are recommended for coalescing water droplets in concentrated emulsions.
- Pure dc electric fields are suggested for coalescing water droplets in dispersed emulsions.
- The contactless charge injection method offers an efficient approach to oil-water separation.
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