Emulsion liquid membranes:: Role of internal droplet size distribution on toluene/n-heptane separation

Using oil/water/oil-type emulsion liquid membranes, batch wise extraction experiments are carried out to separate toluene from a mixture of toluene and n-heptane. In the separation process using emulsion liquid membranes, the internal phase polydispersity affects mass transport of a solute because under steady operating conditions, internal droplet size and size distribution are proportional to the interfacial area. The present study aims to assess the polydispersity character of the internal droplets of emulsion globules. In this paper, the important variables affecting dispersed drop sizes as well as internal droplets mean diameter and size distribution of the emulsion globule, including impeller speed during emulsification, surfactant concentration, volume ratio of surfactant solution, carrier concentration and composition of feed phase are systematically investigated. (c) 2005 Elsevier B.V. All rights reserved.