Using Reduced Pressure Distillation of Azeotropes to Perform Solvent Switches in Chemical Process Development at Scale

Many organic chemists, including Kilomentor, have accumulated tables of lower boiling azeotropes that can be useful when designing work up procedures or solvent switching protocols. These azeotropes are mostly ones that exist at atmospheric pressure. When one thinks more carefully about the actual isolation in a particular scale up, because a solvent exchanging distillation is going to take quite some time, it would be better if the distilling were done at reduced pressure where boiling points are lower and where we can expect less degradation of the solute product we want. The difficulty is to know whether an azeotrope exists at the reduced system pressure we can achieve dependably in the scaled reactor. Fortunately, for a group of common organic solvents the Vapor-Liquid phase diagrams are available for free at http://vle-calc.com/phase_diagram.html

All you need to do is select the solvents you are working with, choose isobaric conditions, choose an x, y, T type diagram, select the pressure you can expect to easily achieve ( pressure units can be selected by clicking on the pressure unit shown) and press the calculate button.

There is a limitation on the solvents that the software can deal with.