Appeal No. 1997-2353 Page 4
Application No. 08/405,912
carbamate and unreacted ammonia from the reaction mixture
leaving a second reaction space and for recycling of the
carbamate, respectively, to the first reaction space and the
ammonia to the second reaction space. We note that the
examiner is of the opinion that “Pagani does not teach
recycling of carbamate and unreacted ammonia, and separation
of urea, carbamate and unreacted ammonia” (answer, page 4).
The examiner does assert, however, that Inoue discloses
separating excess ammonia and carbamate in the synthesis of
urea and that “recycling of carbamate and unreacted ammonia is
old in the art . . .” of urea synthesis as disclosed by Zardi
(answer, page 4). According to the examiner (answer, page 4),
[i]t would have been prima facie obvious to one
of ordinary skill in the art at the time the
invention was made to modify Pagani, by introducing
a separation step of separating excess of ammonia,
carbamate, as taught by Inou [sic] et al., or
alternatively, recycling unreacted ammonia and
carbamate, as taught by Zardi, because the latter
references expressly teach such modification, with
the reasonable expectation of achieving a successful
process of obtaining high yield of urea, absent
evidence to the contrary.
Appellants argue that “[i]t is difficult to see where the
examiner can find a suggestion of this kind” (brief, page 5).
We agree. While the examiner (answer, pages 5 and 6) refers
to various lines of pages 1-3 of Pagani as teaching the use of
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