Appeal No. 2004-2118 Page 2
Application 09/329,502
employed including “an initial alkylation of the aromatic
substrate followed by an intermediate recovery operation and then
transalkylation” (specification, page 2).
Appellants acknowledge that “[i]n both alkylation and
transalkylation, whether conducted in the liquid phase or in the
vapor phase, it is a conventional practice to employ catalysts in
the reactors comprising shape-selective molecular sieves” that
“. . . may be the same or different . . . .” Id. Also,
appellants acknowledge that, while not universal, “it is often
the practice to employ a relatively small to intermediate pore
size molecular sieve such as ZSM-5, ZSM-11, or silicalite in the
alkylation reactor and follow this with a molecular sieve having
a somewhat larger pore size, such as zeolite-Y . . . .”
(appellants’ specification, page 3, first full paragraph).
Appellants use a high porosity zeolite-Y molecular sieve1
having a specified silica/alumina ratio, a specified pore size
and a specified surface area as a catalyst in the transalkylation
1 Appellants refer to a high porosity zeolite-Y as one that
possesses a surface area less than 500 m2/g (specification,
page 9, lines 2-5). At page 15 of the specification, it is
stated that “[t]he foregoing catalyst characteristics are for
the zeolite-Y catalyst as it exists in the crystallite form.”
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