Population Balance Modeling for Integrating Hydrodynamics with Electrostatics in Crude Oil Electrocoalescers

Document Type : Research Paper

Author

Petroleum Refining and Processing Technology Development Division, Research Institute of Petroleum Industry, Tehran, Iran

Abstract

A particular population balance model (PBM) which consists of hydrodynamic and electrostatic parts is developed for electrocoalescence of distributed water droplet in the continuous oil phase. The approach is the modification of a recognized PBM by adding the electrostatic effects on the overall coalescence rate including the number of times (frequency) occurring collision and the efficiency of coalescence. Moreover, the modified model has been being implemented in a CFD-PBM problem for a pilot plant electrocoalescer to predict the profile of water phase and size distribution of droplets. The results recognize the effect of local electric field intensity and local water content on electrocoalescence rate. Furthermore, the results demonstrate that separation for the very small droplets (<4μm) is minor, for the medium sizes (8-32μm) is more considerable, and for larger droplets (>64μm) occurs completely. Ultimately, by making a comparison between the simulation results and the pilot data, the EHD PB model is validated.
 

Keywords


REFERENCES
Mohammadi M., Shahhosseini S., and Bayat M., “Direct Numerical Simulation of Water Droplet Coalescence in the Oil,” International Journal of Heat and Fluid Flow, 2012, 36, 58-71.
Lee C. M., Sams G. W., and Wagner J. P., “Power Consumption Measurements for Ac and Pulsed dc for Electrostatic Coalescence of Water-in-oil Emulsions,” Journal of Electrostatics, 2001, 53(1), 1-24.
Guo C. and He L., “Coalescence Behaviour of Two Large Water-drops in Viscous Oil under a DC Electric Field,” Journal of Electrostatics, 2014, 72(6), 470-476.
Mohammadi M., Shahhosseini S., and Bayat M., “Numerical Prediction of the Electrical Waveform Effect on Electrocoalescence Kinetic,” Chemical Engineering Research and Design, 2013, 91(5), 904-918.
Mohammadi M., Shahhosseini S., and Bayat M., “Numerical Study of Collision and Coalescence of Water Droplets in an Electric Field,” Chemical Engineering and Technology, 2014, 37(1), 27-35.
Mohammadi M., Shahhosseini S., and Bayat M., “Electrocoalescence of Binary Water Droplets Falling in Oil: Experimental Study,” Chemical Engineering Research and Design, 2014, 92, 2694-2704.
Soni P., Juvekar V. A., and Naik V. M., “Investigation on Dynamics of Double Emulsion Droplet in a Uniform Electric Field,” Journal of Electrostatics, 2013, 71(3), 471-477.
Mohammadi M., “Numerical and Experimental Study on Electric Field Driven Coalescence of Binary Falling Droplets in Oil,” Separation and Purification Technology, 2017, 176, 262-276.
Verdoold S., and Marijnissen J. C. M., “Modeling a Bipolar-coagulation Reactor Using Coupled Population Balances,” Journal of Electrostatics, 2011, 69(3), 240-254.
Coulaloglou C. A., and Tavlarides L. L., “Description of Interaction Processes in Agitated Liquid-liquid Dispersions,” Chemical Engineering Science, 1977, 32(11), 1289-1297.
Prince M. J., and Blanch H. W., “Bubble Coalescence and Break-up in Air-sparged Bubble Columns,” AIChE Journal, 1990, 36(10), 1485-1499.
Tsouris C., Tavlarides L. L., “Breakage and Coalescence Models for Drops in Turbulent Dispersions,” AIChE Journal, 1994, 40(3), 395-406.
Lehr F., Millies M., and Mewes D., “Bubble-size Distributions and Flow Fields in Bubble Columns,” AIChE Journal, 2002, 48(11), 2426-2442.
Guo C., He L., and Xin Y., “Deformation and Breakup of Aqueous Drops in Viscous Oil under a Uniform AC Electric Field,” Journal of Electrostatics, 2015, 77, 27-34.
He L., Huang X., Luo X., and Yan H., “Numerical Study on Transient Response of Droplet Deformation in a Steady Electric Field,” Journal of Electrostatics, 2016, 82, 29-37.
Abbasi M. S., Song R., Kim J., and Lee J., “Electro-hydrodynamic Behavior and Interface Instability of Double Emulsion Droplets under High Electric Field,” Journal of Electrostatics, 2017, 85, 11-22.
Drumm C., Attarakih M. M., and Bart H. J., “Coupling of CFD with DPBM for an RDC Extractor,” Chemical Engineering Science, 2009, 64(4), 721-732.
Kamp J. and Kraume M., “Coalescence Efficiency Model Including Electrostatic Interactions in Liquid/liquid Dispersions,” Chemical Engineering Science, 2015, 126, 132–142.
Israelachvili J. N., “Ntermolecular and Surface Forces,” (2nd ed.) Academic Press: London, UK, 1991.
Derjaguin B. V., Churaev N. V., and Muller V. M.,  “Surface Forces,” Consultants Bureau: New York, USA, 1987.
Barega E. W., Zondervan E., and De Haan A. B., “A Combined Lossy Capacitor Population Balance Model (LCPBM) for Calculating the Influence of Frequency on Electric Field Enhanced Coalescence in a Static-mixer Settler Setup,” Chemical Engineering Science, 2013, 104, 727-741.
Meidanshahi V., Jahanmiri A., and Rahimpour M. R., “Modeling and Optimization of Two Stage AC Electrostatic Desalter,” Separation Science and Technology, 2012, 47, 30–42.
Aryafard E., Farsi M., and Rahimpour M. R., “Modeling and Simulation of Crude Oil Desalting in an Industrial Plant Considering Mixing Valve and Electrostatic Drum,” Chemical Engineering and Processing, 2015, 95, 383–389.
Aryafard E., Farsi M., Rahimpour M. R., and Raeissi S., “Modeling Electrostatic Separation for Dehydration and Desalination of Crude Oil in an Industrial Two-stage Desalting Plant,” Journal of the Taiwan Institute of Chemical Engineers, 2016, 58, 141–147.
Manga M., and Stone H., “Collective Hydrodynamics of Deformable Drops and Bubbles in Dilute Low Reynolds Number Suspensions,” Journal of Fluid Mechanics, 1995, 300, 231-263.
Atten P., “Electrocoalescence of water droplets in an insulating liquid,” Journal of Electrostatics, 1993, 30, 259-270.
Ramkrishna D., “Population Balances: Theory and Applications to Particulate Systems in Engineering,” Academic Press: San Diego, USA, 2000.
Kumar S., and Ramkrishna D., “On the Solution of Population Balance Equations by Discretization-I. A Fixed Pivot Technique,” Chemical Engineering Science, 1996, 51(8), 1311-1332.
Kumar J., Peglow M., Warnecke G., and Heinrich S., “Improved Accuracy and Convergence of Discretized Population Balance for Aggregation: The Cell Average Technique,” Chemical Engineering Science, 2006, 61(10), 3327-3342.
Lister J. D., Smit D. J., and Hounslow M. J., “Adjustable Discretized Population Balance for Growth and Aggregation,” AIChE Journal, 1995, 41(3), 591-603.