The invention relates to a process for the preparation of phenol comprising the
following phases:
1) preparation in continuous of phenol by means of the direct oxidation
of benzene with hydrogen peroxide operating with an H2O2/benzene
ratio ranging from 10 to 70%, in a three-phase reaction system comprising a first
liquid phase consisting of benzene and an organic solvent, a second liquid phase
consisting of water, a solid phase consisting of an activated catalyst based on
titanium silicalite TS-1;
2) separation of the phenol and non-reacted benzene from the reaction mixture
of the oxidation section (1), by means of fractionated distillation;
3) separation of the solvent and by-products from the mixture coming from
the distillation tail (2), by means of basic extraction;
4) transformation of the by-products obtain in section (3) to phenol by
means of hydrodeoxygenation with hydrogen operating in continuous, in aqueous solution,
at a temperature ranging from 250 to 500 C., at pressures of 1-100 bar and
in the presence of a catalyst based on elements of group VIB or their mixtures
or group VIII of the periodic table or their mixtures;
5) recycling of the phenol obtained in section (4) to the distillation section (2).
|
|
|
