This book is designed to bridge the gap between handbooks and technical literature and is intended to serve the research needs of both academic and industrial scientists and graduate students. It begins with a discussion on reactive extraction systems and provides a state-of-the-art description of phase equilibria in reacting liquid-liquid systems. The following chapter discusses reactive mass transfer with a focus on transfer regimes, surfactant layers, zeta potential and experimental techniques. A brief summary on current developments and not common extraction techniques is also offered. A program for column design which is available from the author's homepage is described in Appendix X, and references to other license free codes in the web are also given.