Appeal No. 1997-4399
Application 08/505,338
It is well settled that “[t]he consistent criterion for determination of obviousness is whether the
prior art would have suggested to one of ordinary skill in the art that [the claimed process] should be
carried out and would have a reasonable likelihood of success, viewed in the light of the prior art.
[Citations omitted] Both the suggestion and the expectation of success must be founded in the prior art,
not in the applicant’s disclosure.” In re Dow Chem. Co., 837 F.2d 469, 473, 5 USPQ2d 1529, 1531
(Fed. Cir. 1988). Thus, a prima facie case of obviousness is established by showing that some
objective teaching, suggestion or motivation in the applied prior art taken as a whole and/or knowledge
generally available to one of ordinary skill in the art would have led that person to the claimed invention
as a whole, including each and every limitation of the claims, without recourse to the teachings in
appellants’ disclosure. See generally, In re Rouffet, 149 F.3d 1350, 1358, 47 USPQ2d 1453, 1458
(Fed. Cir. 1998); Pro-Mold and Tool Co. v. Great Lakes Plastics Inc., 75 F.3d 1568, 1573,
37 USPQ2d 1626, 1629-30 (Fed. Cir. 1996); In re Oetiker, 977 F.2d 1443, 1447-48, 24 USPQ2d
1443, 1446-47 (Fed. Cir. 1992) (Nies, J., concurring); In re Laskowski, 871 F.2d 115, 10 USPQ2d
1397 (Fed. Cir. 1989); In re Fine, 837 F.2d 1071, 1074-76, 5 USPQ2d 1596, 1598-1600 (Fed.
Cir. 1988). We agree with appellants that the examiner has failed to carry his burden of making out a
prima facie case of obviousness with respect to the claimed invention.
We find that the process for the selective removal of hydrogen sulphide from gas containing
hydrogen and carbon dioxide by absorption in carbonate-containing alkaline solutions is specified in
appealed claim 1 to “multiple stages of circulating carbonate-containing alkaline solutions” and
“adjusting the pH in each stage . . . to about 9-12 by the addition of a hydroxide” to obtain a “total
sulphide content exceeding about 0.30 mole/l in the outgoing solution.” Thus, the claim requires at least
that the hydrogen sulphide must be recovered as a sulphide.
We find that Murray discloses that the prior art process of merely absorbing hydrogen sulphide
in an alkaline solution from a gas containing the sulphide and carbon dioxide is inefficient (col. 2, lines
19-33). Murray teaches that the absorption of hydrogen sulfide by maintaining the aqueous alkaline
solution, which contains sodium ions and preferably carbonate ions, at a pH of about 9.0 and above so
3 The examiner withdrew the ground of rejection of claims 1 through 8 and 11 under § 103 as being
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