Appeal No. 2003-0172
Application 09/810,801
The appellants state that “[a]lthough it may arguably be
obvious to use low asphaltene feeds in the Wernicke two-step
process, there is nothing to suggest to one of ordinary skill in
the art to use low asphaltene feeds in a non-obvious one-step
process” (appeal brief, page 6). Thus, the appellants do not
argue that it would have been unobvious to one of ordinary skill
in the art to use, in the Wernicke two step process, a crude oil
feed having low asphaltenes, i.e., pentane insolubles less than
or equal to 1.2. The appellants’ argument is that it would not
have been obvious to one of ordinary skill in the art to
thermally steam crack this crude oil without first hydrotreating
it.
The appellants argue that the statement in Wernicke ‘520
that “[p]etroleum fractions having such a boiling range [380ºC to
700ºC] are unsuitable for direct thermal cracking, since besides
a small yield of olefins, additional products are pyrolysis oil,
coke, and tar” indicates that hydrotreatment is necessary before
petroleum fractions within the boiling range of the crude oil of
the appellants’ invention are thermally steam cracked (brief,
page 5). In the Wernicke ‘520 examples, however, the feed gas
oil has a boiling range of 208-354ºC, which is below the range in
the above excerpt. Wernicke ‘520 does not state that the lower
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