COMBINED METHOD OF OBTAINING PHENOL FROM BENZOL WITH BY-PRODUCT RE-CYCLE Russian patent published in 2008 - IPC C07C37/60 C07C39/04 B01J29/89 

FIELD: chemistry.

SUBSTANCE: at first stage by continuous method phenol is obtained by direct benzol oxidation with hydrogen peroxide with ratio of H₂O₂/benzol from 10 to 70% mol., in three-phase reaction system, which includes first liquid phase, consisting of benzol and organic solvent, second liquid phase, consisting of water, and solid phase, consisting of activated catalyst, which contains titanium silicate TS-1. At second stage phenol and benzol which has not reacted are separated from reaction mixture by fraction distillation. At third stage solvent and by-products, containing dioxybenzols, are separated from mixture, supplied from tail fraction of second stage distillation, by extraction with base obtaining water solution of dioxybenzols. At fourth stage obtained water solution of dioxybenzols is converted into phenol by hydrodeoxygenation with hydrogen in conditions of continuous operation at temperature from 250 to 500°C, pressure 0.1-10 MPa and in presence of catalyst containing element of group VIB or their mixture or element of group VIII of periodic system or their mixture and promoter. At fifth stage obtained by re-cycle at previous stage phenol is supplied to distillation stage.

EFFECT: increase of degree of benzol conversion and selectivity on phenol, elimination of diphenol formation and reduction of solvents quantity.

22 cl, 8 ex, 1 dwg