Appeal No. 1997-1551
Application No. 08/235,597
removing substantially all the SO3 from the flue gas.
The examiner points to appellants= Aadmission@ at p. 5, lines 3 and 4, of the
specification that A(i)t is well-known in the pollution control field that a
wet scrubber does not effectively remove SO3 from flue gas.@
The examiner further notes that Kohl teaches that SO3 is Ahighly corrosive.@
In light of the Aadmission@ and the Kohl teaching, the examiner concludes that
there would have been Aexpected advantages of being able to remove
highly corrosive SO3 out
of the flue gas before it can damage any equipment or the environment
and also because it is know that wet-scrubbers are not efficient at
removing SO3 out of a gas.@
The examiner points to Peterson, p. 6A-3, as showing that Ca(OH)2 and NaHCO3 can
remove not only SO3 out of a gas but SO2 as well. The examiner further notes
that claim 2 would encompass both Ca(OH)2 and NaHCO3.3
The examiner argues in the paragraph bridging pp. 5 and 6 of his September
27, 1996 Answer that Peterson suggests both SO2 and SO3 may be
removed by Ca(OH)2 and NaHCO3 in a wet scrubber.
It should be noted, however, that the sorbents taught in Peterson are dry. See
p. 6A-2, para. 2; p. 6A-6, para. 2; and p. 6A-18, Table 1.
The examiner cites Steag for its teaching on the dry cleaning of flue gas after the particulate
collection step.
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