Patent ID: 6881853

Claim:
A process for preparing propylene oxide, which comprises at least the following steps: (a) propene is reacted with a hydroperoxide in a solvent in the presence of a zeolite catalyst to give a mixture (M 0 ), where the mixture (M 0 ) comprises propylene oxide, solvent, unreacted propene, unreacted hydroperoxide and oxygen, (b) the propylene oxide is separated from the mixture (M 0 ) so as to give a mixture (M 1 ) which comprises unreacted propene and oxygen, (c) the mixture (M 1 ) is brought into contact with a liquid medium comprising at least a solvent to give the mixtures (M 2 ) and (M 3 ), where the mixture (M 3 ) comprises part of the unreacted propene and oxygen and the mixture (M 2 ) comprises solvent and residual propene, and where the mixture (M 3 ) which has been separated off and comprises unreacted propene and oxygen has a ratio of oxygen to propene such that the mixture (M 3 ) is not ignitable, and where the mixture (M 2 ) is fed to at least one reaction of propene with hydroperoxide.