Integrated process for the preparation of phenol from benzene with recycling of the by-products

• Main Authors: Bortolo, Rossella, Bianchi, Daniele, Buzzoni, Roberto, Cesana, Alberto, Dalloro, Leonardo, D'Aloisio, Rino
• Format: Patent
• Language: English
• Published: 24.06.2004

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 H 2 O 2 /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).