Frank Steyer

Synthesis of cylohexanol by three-phase reactive distillation: influence of kinetics on phase equilibria

A reactive distillation process is being suggested for the production of the commercially interesting intermediate cyclohexanol from cyclohexene and water, which avoids some of the drawbacks of the conventional liquid-phase cyclohexane oxidation process, especially with respect to operational safety. This reactive distillation process has its own intricate challenges due to the fact that reaction, distillative separation and liquid-phase splitting occur simultaneously. The interaction of these three phenomena is studied using residue curve maps for both, model simulations and experimental data. Based on the fixed point analysis of the residue curves, a novel process is proposed for the reactive separation of cyclohexene/cyclohexane mixtures which is difficult to be carried out by conventional distillation due to very close boiling temperatures.

Equilibrium and rate-based approaches to liquid–liquid phase splitting calculations

Abstract Several approaches are presented that can be used to compute liquid–liquid phase splitting. These approaches are based on homotopy continuation methods or on non-equilibrium thermodynamics. It is shown that they exhibit quite different computational demands with respect to computation times and a suggestion is made as to which algorithm to use. For chemical systems with only a few components, the computation times encountered on a normal PC in most cases are only a few milliseconds, in some cases even less—suggesting the general use of such algorithms to assure that phase splitting is always detected when present.