Regeneration of Fibrous Bed Coalescers for Oil-Water Separation B. Shah, W. Langdon, and D. Wasan’ Department of Chemical Engineering, Illinois Institute of Technology, Chicago, 111. 60616
The regeneration of fibrous bed coalescers operating on secondary oil-in-water emulsions was studied. Unstabilized or commercially available glass fibers were used, and the latter fibers were bound together into a rigid structure or stabilized by application of isobutyl methacrylate resin on the fibers and the subsequent heat treatment. The efficiency of these coalescers was close to 100% for several hours and then fell off rapidly. The cycle life, defined as the time when the concentration of the effluent emulsion reaches 5 ppm, was of the order of 6 h. Steam was an easily applicable and efficient regenerating agent. Steam regeneration of stabilized beds gave cycle lives 0.8 that of fresh bed. The cycle life of stabilized bed varied inversely with superficial velocity and was independent of inlet concentrations in the range of 100-200 ppm (v/v). The stabilized beds were regenerated three times without an appreciable decrease in cycle life.
Pollution of inland waterways and coastal waters by effluents containing waste oil from many industries and commercial and naval vessels has adverse effects on marine and human life. The oil can be present in the form of an emulsion of fine droplets due ‘to wave action and particularly so if subjected to pumping. Primary emulsions (droplet size > 10 11) may be easily separated by gravity settling. However, secondary emulsions (droplet size
