A powerful algorithm for liquid-liquid-liquid equilibria predictions and calculations

The paper describes a new robust and efficient algorithm for liquid-liquid- liquid equilibria (LLLE) predictions and calculation. The architecture of t he algorithm is a two-level one, and a judicious combination of a stability analysis, carried out in the first stage, with phase identification routin es and liquid flash calculations, carried out in the second stage, is reali sed. The numerical routines require modest computational efforts and demons trate excellent convergence characteristics. The thermodynamic model applie d to a system does not influence the robustness of the new algorithm, which can treat any model and handle any number of components and phases. The us efulness and efficiency of the new algorithm is exemplified by using two mo del systems, a water + oil + non-ionic surfactant system and the system eth ylene glycol + lauryl alcohol + nitromethane. (C) 2000 Elsevier Science Ltd . All rights reserved.