REGULATION OF THE CHLORINE CONTENT IN FRESH, REGENERATED AND COKED PTRE AL2O3 CATALYST/

In bifunctional naphtha reforming catalysts the regulation of the chlo rine content in order to equilibrate both catalytic functions (metalli c and acidic) is one of the most relevant topics. In this paper a stud y of the chlorine regulation in fresh, regenerated and coked samples o f a given commercial Pt (0.3 wt %)-Re (0.3 wt %)/Al2O3) catalyst is pr esented. Results show that an equilibrium chlorine content is reached when the samples are treated with an H2O-HCl mixture vaporized in a ga s carrier (air or H-2). This equilibrium content depends on the H2O/HC l molar ratio and the temperature of the regulation treatment. For fre sh samples the equilibrium chlorine content does not depend on the nat ure of the gas carrier. Moreover, the retention capacity of chlorine b y the support per unit of surface area is the same for fresh and regen erated samples. The presence of different amounts of coke on the surfa ce does not modify the chlorine uptake with respect to the sample with out coke.