Determination of the Kinetics of the Ethoxylation of Octanol in Homogeneous Phase

A two-dimensional computational fluid dynamics model was utilized to test different kinetic models for the description of the anionic polymerization of octanol with ethylene oxide in a microreactor. The reaction was performed as a continuous reaction under elevated pressure and temperatures in a one-phase system. The kinetic parameters were determined with numerical methods by reducing the deviation to experimental data based on the Nelder–Mead method. Four different reaction models with one, two, three, and four different rates for the first propagation steps were tested. The best agreement with the experimental data was found for the four rate model, with a prediction accuracy close to the experimental error. The gathered data suggests an increasing reaction rate for the first four propagation steps, which is in agreement with the Weibull–Törnquist effect [Weibull and Törnquist. Berichte vom VI. Internationalen Kongress für Grenzflächenaktive Stoffe, Zürich, vom 11. bis 15. September 1972; Carl Hanser Verlag: Munich, 1972; p 125; Sallay et al. Tenside Deterg. 1980, 17, 298].