Effect of Colloidal Particles on the Emulsion Stability in Oily Waste Sludge

Kim, Young H.; Kim, Chul U.

Environmental Engineering Research 1997;2(3): 159-171.

¹Dept. of chem. Eng., Ansung National University, Kyunggi-Do 456-749, Korea
²Chem. Eng. Research Center, Korea Research Institute of Chemical Technology, Taejon 305-600, Korea

Corresponding Author: Young H. Kim ,

Received: July 22, 1996; Accepted: April 21, 1997.

ABSTRACT

The effects of the colloidal particles on the stability of the water-in-oil emulsion formed in oily waste sludge were studied. The dispersed subrnicron solid particles that are composed of asphaltene/resin particle stabilized the emulsion film formed between approaching the emulsion drops. It was found that, when the effective volume concentration of the particles is sufficiently high and their polydispersity is low, the sub-micron particles form a layering structure inside the film. The particle long-range structure stopped the film thinning during film drainage and stabilized the emulsion film. The size distribution of the asphaltene/resins colloidal particles was affected by the type of the crude oil phase (solute-solvent interactions). When the oil phase has a low solvency for the asphaltene/resins, the emulsion stability was decreased by diminishing the long-range particle structure due to the particle aggregation. The aggregated particle cluster was re-dispersed when the oil was blended with a different high solvency oil, resulting in a higher emulsion stability. A high performance chemical demulsifier aggregated the sub-micron asphaltene/resins particles and effectively separated the water phase from the oil sludge by lowering the emulsion stability due to diminishing the particle-particle in U tactions.

Keywords: sludge | emulsion stability | demulsification