Propylene → Propionic Acid

The substantially dry organic solution is now fed by the line 121 to a reactor 122 which is conveniently illustrated as a column, although in practice a long tubular reactor would be preferred. Propylene is also fed to this reactor by a line 123 from a storage vessel 124. It will be appreciated that under normal conditions of temperature and pressure, propylene is a gas and therefore the reactor 122 is operated under pressure in order that the propylene should be kept in solution in the organic solution. The propylene reacts with the perpropionic acid in the reactor 122 to give propylene oxide and propionic acid in accordance with step (e). This product mixture is taken by a line 125 to a first distillation column 126 and in this column any unreacted propylene is distilled off as a light fraction and is passed by a line 127 to a condenser 128. In the condenser 128 the propylene is condensed and is fed by a line 129 back to the reactor 122. Any uncondensible gases are passed to waste through a line 130.