Appeal 2006-2691
Application 09/942,830
invention to use a sulfur-containing organic additive with the catalysts in the
HDS process of Hatanaka for the advantages taught by the Takahashi
references (id.). We agree.
Appellants argue that the “crux of this appeal” is the “fundamental
difference” between the ultra-deep HDS process as compared to
conventional HDS (Br. 5). Appellants submit that conventional HDS
reduces the sulfur content of a hydrocarbon feedstock to values of about
1500 ppm, removing compounds such as sulfides, disulfides, thiophenes,
and benzothiophenes, while ultra-deep HDS reduces the sulfur content to
less than about 50 ppm, primarily removing alkylated benzothiophenes (Br.
5-6). Appellants argue that the reacting compounds and reaction mechanism
for the two processes are so different that the catalysts one skilled in the art
would expect to provide good results in a conventional HDS do not perform
as well in ultra-deep HDS (Br. 6). Appellants agree with the Examiner that
Hatanaka is directed to ultra-deep HDS, with the sulfur content reduced to as
low as 30 ppm (Br. 6, citing Hatanaka, Example 3). However, Appellants
argue that all the Takahashi references are directed to similar conventional
HDS processes (Br. 6-7), and thus there would be no teaching, suggestion,
or motivation to combine the disclosures of the references (Br. 7).
Appellants also argue that Hatanaka is concerned with three reaction zones
to finally reduce the sulfur content to less than 50 ppm, while the Takahashi
references are directed to HDS processes similar to that of the first reaction
zone of Hatanaka (Br. 7).
Appellants’ arguments are not persuasive. In contrast to Appellants’
arguments, Appellants disclose that “[i]n the context of the present
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