Appeal No. 98-3017 4
Application No. 08/437,986
We do not reach the rejection under section 112, first paragraph for the reasons stated
infra, and we enter a new rejection in accordance with 37 CFR § 1.196(b).
The Rejection over the Burress in view of Parker
Burress discloses a process for the isomerization of xylene together with the
conversion of ethyl benzene content. See column 4, lines 55-58. The process utilizes a
mixture of a C8 aromatic hydrocarbon feed. See column 5, line 30. As an initial step,
the feed passes to distillation in an ethyl benzene tower 2, from which a portion of the
ethyl benzene content is taken overhead by line 3. It is impracticably expensive to
attempt removal of substantially all of the ethyl benzene by tower. See column 5, lines
34-38.
In contrast Parker discloses hydrocarbon conversion of ethyl benzene in a mixed
xylene-ethyl benzene feedstock by contacting the feedstock with a zeolite catalyst which
results in ethyl benzene destruction. Preferably the ethyl benzene is cracked to form
ethylene and benzene. See Abstract, page 1, lines 3-7, and page 2, lines 35-36.
The examiner argues that Appellants’ pretreatment step corresponds to the
cracking step of Parker when applied to a feedstock of C8 aromatics. See Answer, page
5. Accordingly, the examiner concludes that, “[i]t would have been obvious to one of
ordinary skill in the art to apply the teaching of Parker to the disclosure of Burress with a
reasonable expectation of obtaining a highly-useful method of purifying a xylene isomer
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