Liquid-Liquid Extraction: Phase Diagrams and Calculations

This lecture focuses on the liquid-liquid extraction process, particularly when solvents and diluents are partially miscible. The instructor begins by discussing the differences in system behavior when dealing with partially miscible solvents and diluents, emphasizing the need for triangular phase diagrams to analyze compositions. The lecture covers the calculation of the number of stages required for countercurrent operations and introduces the concept of equilibrium relationships in partially miscible systems. The instructor explains how to read triangular phase diagrams and apply Viviani's theorem to determine compositions. The lecture also includes practical examples and exercises, illustrating how to calculate the flow rates and compositions of various streams in a countercurrent extraction setup. The importance of mass and energy balances in these calculations is highlighted, along with the use of operating lines and tie lines to establish relationships between different phases. Overall, the lecture provides a comprehensive understanding of the complexities involved in liquid-liquid extraction processes.