PROCESS FOR REGENERATING MONOLITHIC HYDROGENATION CATALYTIC REACTOR

摘要

PURPOSE: A process to regenerate monolithic catalytic reactors employed in the liquid phase hydrogenation reactions, particularly those kinds of reactions involving nitroaromatic compounds is provided. CONSTITUTION: In a process for the heterogeneous catalytic reaction of a mixture of a reactant gas and reactant liquid in a monolith catalytic reactor carrying a catalytic metal under conditions of liquid phase reaction for a time sufficient to generate carbonaceous and deactivating byproducts, the improvement for regenerating the catalytic activity of the monolith catalytic reactor and thereby extend the life of the monolith catalytic reactor comprises the steps of initially passing an oxidizing gaseous mixture through the monolith catalytic reactor at an elevated temperature and for a time sufficient to remove carbonaceous and deactivating byproducts; and then, passing a reducing gas though the monolith catalytic reactor previously exposed to the oxidizing gas under conditions for reducing the catalytic metal to its reduced state. In a process for the heterogeneous catalytic reaction of a mixture of a hydrogen and dinitrotoluene in a monolith catalytic reactor carrying nickel and palladium as catalytic metals under conditions of liquid phase reaction for a time sufficient to generate carbonaceous and deactivating byproducts, the improvement for regenerating the catalytic activity of the monolith catalytic reactor and thereby extending the life of the monolith catalytic reactor comprises the steps of initially passing an oxidizing gaseous mixture through the monolith catalytic reactor at an elevated temperature and for a time sufficient to remove carbonaceous and deactivating byproducts; and then, passing a reducing gas though the monolith catalytic reactor previously exposed to the oxidizing gas under conditions for reducing the catalytic metals to its reduced state.