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Keywords:

  • filtration;
  • deposition;
  • trickle bed;
  • capacitance tomography;
  • hydrodynamics

Abstract

Modulation of electrical conductivity in kaolin/kerosene suspensions was examined as a means for the attenuation of fines retention in trickle-bed reactors. The suspension stability was remarkably enhanced through ON-OFF concentration modulation of an electrolyte-based kerosene conductivity improver and resulted in an efficient bed-cleaning strategy under operating conditions. Periodic additions of the conductivity improver enabled fines and deposits to gain momentarily large and similar electrical charges undoing, or impeding, multilayer deposition. The time evolution of the two-phase pressure drop and specific deposit with/without conductivity improver was monitored, as well as the corresponding local deposition structure via electrical capacitance tomography (ECT). Electrical conductivity modulation was found to reduce the bed-specific deposit by an order of magnitude and the bed pressure drop increment by a factor 14. ECT imaging evaluated the efficacy of this modulation strategy in mitigating deposition and in preventing filtration-induced flow maldistribution. © 2010 American Institute of Chemical Engineers AIChE J, 2011