Abstract: Publisher Summary The objective of this chapter is to provide comprehensive knowledge-based information by critical analysis, classification, model description, and applications of a variety of emulsion liquid membrane (ELM) separation processes. It also discusses new perspectives and directions of development in these fields. Liquid membrane separations have been extensively examined for potential application in many fields such as metal recovery, gas separation, organic compound removal, pollutant removal, and bioseparations. The difficulties in the application of these processes did not consist in sophisticated equipment or installation but in the adequate choice of reagent to allow the selective extraction of solute in required quantity. The widespread use of the ELM process has been limited due to the instability of emulsion globules against fluid shear. Numerous studies have attempted to enhance the stability of ELMs. Examples include adding more surfactants into the membrane phase and increasing the membrane viscosity. However, in most reported attempts increased stability has been unfortunately accompanied by loss in extraction efficiency and rate. A unique contacting device, a Taylor-Couette column, provides a relatively low and uniform fluid shear that helps maintain the stability of emulsion without compromising the extraction efficiency of a target compound. Current research has also been directed to minimizing membrane leakage or rupture through the use of bifunctional surfactants, which act as both emulsifier and extractant, and on additives (e.g., polymer) to impact elasticity of membrane.