Catalyst Regenerator for Partial Oxidation of Benzene in Reaction-extraction System

Abstract

The liquid-phase oxidation of benzene to phenol was investigated in the biphasic benzene-water system using VCl3 and molecular oxygen as the catalyst and oxidant, respectively. Benzene was dissolved in the aqueous catalyst phase and reacted with oxygen to form phenol. Phenol was preferentially extracted into the benzene phase, thus suppressing the formation of over-oxidized byproducts. During the reaction, the catalyst was oxidized and deactivated. To regenerate the catalyst, a regenerator was installed into the system. Hydrogen was fed to the regenerator to reduce the deactivated catalyst, but no significant improvement of the system performance was observed without the presence of a second catalyst. Pd sheet in the regenerator allowed the system to run very stably, and the system was easy to shut down and start up.