Patent ID: 8481443

Claim:
A catalyst system for transalkylation of a C 9 +aromatic hydrocarbon feedstock with a C 6 -C 7 aromatic hydrocarbon, the catalyst system comprising: (a) a first catalyst bed comprising (i) a first molecular sieve having a Constraint Index in the range of about 3 to about 12 and (ii) at least first and second different metals or compounds thereof of Groups 6-12of the Periodic Table of the Elements; and (b) a second catalyst bed comprising a second molecular sieve having a Constraint Index less than 3; wherein the weight ratio of said first catalyst to said second catalyst is in the range of about 5:95 to about 75:25 and wherein said first catalyst bed is located upstream of said second catalyst bed when the catalyst system is brought into contact with said C 9 +aromatic hydrocarbon feedstock and said C 6 -C 7 aromatic hydrocarbon in the presence of hydrogen; and (c) a third catalyst bed comprising a third molecular sieve having a Constraint Index in the range of about 3 to about 12, wherein said third catalyst bed is located downstream of said second catalyst bed when the catalyst system is brought into contact with said C 9 +aromatic hydrocarbon feedstock and said C 6 -C 7 aromatic hydrocarbon in the presence of hydrogen; wherein said first metal is at least one of platinum, palladium, iridium, and rhenium, present in the first catalyst in an amount between about 0.001 and about 5 wt % of the first catalyst, wherein said second metal is at least one of copper, silver, gold, ruthenium, iron, tungsten, molybdenum, cobalt, nickel and zinc, present in the first catalyst in an amount between about 0.001 and about 10 wt % of the first catalyst.