Appeal No. 1997-1371
Application 08/213,290
upon Griggs and Friend as evidence of obviousness. Claim 2, which depends
from claim 1, further stands rejected under 35 U.S.C. § 103, with the examiner
relying upon Griggs, Friend, Suzuki, and Barker as evidence of obviousness.
We reverse.
The claims at issue
B. Claim 1, representative of the claims on appeal, is directed to a method of
producing bleached wood pulp comprising the steps summarized as follows:
1. digesting wood chips to produce brownstock pulp and weak black liquor;
2. washing the brownstock pulp and extracting the weak black liquor;
3. introducing the brownstock pulp into an oxygen delignification stage utilizing
an oxygen containing stream;
4. thereafter introducing the brownstock pulp into an ozone bleaching stage
utilizing an ozone/oxygen containing stream and producing a waste stream
principally containing water vapor, carbon dioxide, ozone, and oxygen;
5. scrubbing the waste stream with an aqueous solution containing sodium
sulfide and sodium hydroxide to –
a. remove ozone and carbon dioxide from the waste stream;
b. form a scrubbed stream; and
6. using the scrubbed stream to form at least part of the oxygen containing
stream for the oxygen delignification stage.
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