Patent ID: 6313363
Filing Date: 2001-11-06
Classification: B01J,C07C,Y02P,Y10S

Abstract:
A process for isomerising an aromatic compound containing eight carbon atoms per molecule, wherein a catalyst undergoes an activation process by subjecting the catalyst to at least one sulphurization and at least one passivation using ammonia wherein the passivation comprises a first stage wherein the catalyst is brought into contact at least once with ammonia in the form of a gas or in the form of an ammonia precursor prior to the introduction of an isomerisation feed; the process comprising adding hydrogen and a recycle mixture to the isomerisation feed at a reactor inlet, isomerizing at least one reactant from the recycle mixture and/or feed catalyzed by the sulphated and passivated catalyst; said recycle mixture consisting essentially of compounds having a boiling point of about 80.degree. C.--about 135.degree. C. comprising at least one acyclic paraffin containing eight carbon atoms per molecule, at least one naphthene containing eight carbon atoms per molecule, benzene, and toluene, and being devoid of (a) aromatic hydrocarbons containing at least eight carbon atoms per molecule and (b) paraffinic hydrocarbons containing 1-7 carbon atoms per molecule; said recycle mixture being obtained, at least partially, by recycling a fraction separated from the resulting effluent leaving the isomerization reactor.