Exxon Research v. U.S.

• Decision Date: 19 September 2001
• Docket Number: No. 00-5077,00-5077
• Citation: 265 F.3d 1371,60 USPQ2d 1272
• Parties: (Fed.Cir. 2001) EXXON RESEARCH AND ENGINEERING COMPANY, Plaintiff-Appellant, v. UNITED STATES, Defendant-Appellee
• Court: U.S. Court of Appeals — Federal Circuit

Page 1371

265 F.3d 1371 (Fed.Cir. 2001)

EXXON RESEARCH AND ENGINEERING COMPANY, Plaintiff-Appellant, v. UNITED STATES, Defendant-Appellee.

No. 00-5077

United States Court of Appeals for the Federal Circuit

September 19, 2001

Appealed from: United States Court of Federal Claims, Judge Edward J. Damich E. Edward Bruce, Covington & Burling, of Washington, DC, argued for plaintiff-appellant. With him on the brief were Christopher N. Sipes, and Kevin C. Newsom. Of counsel on the brief were Steven D. Glazer, James W. Quinn, Kevin McMahon and Elizabeth S. Weiswasser, Weil, Gotshal & Manges LLP, of New York, New York. Of counsel were Matthew D. Powers, David J. Lender, and Peter Tu, Weil Gotshal & Manges, LLP.

Grace S. Karaffa, Attorney, Commercial Litigation Branch, Civil Division, Department of Justice, of Washington, DC, argued for defendant-appellee. With her on the brief was Vito J. DiPietro, Director. Of counsel on the brief were Thomas J. Byrnes, Richard T. Ruzich, and Ken B. Barrett, Attorneys.

Before MAYER, Chief Judge, LOURIE and BRYSON, Circuit Judges.

BRYSON, Circuit Judge.

Exxon Research and Engineering Co. is the assignee of U.S. Patent Nos. 5,292,705 ("the '705 patent") and 5,348,982 ("the '982 patent"), which are directed to improvements in a method for converting natural gas into liquid hydrocarbon products. Exxon brought suit against the United States in the Court of Federal Claims, asserting that the government infringed the '705 and '982 patents by authorizing Department of Energy subcontractors to use conversion methods covered by the patents. The government filed a motion for summary judgment seeking to have both patents held invalid for indefiniteness. In a detailed and careful opinion, the Court of Federal Claims granted the government's motion, and Exxon appealed. We conclude that, although this case presents several close questions, the claims at issue are not invalid for indefiniteness. Accordingly, we reverse the court's judgment of invalidity with respect to the two Exxon patents and remand the case for further proceedings.

I

The '705 and '982 patents relate to improvements in what is known as the Fischer-Tropsch process for converting natural gas to liquid hydrocarbon products. As the process is described in the patents, natural gas is first broken down to produce synthesis gas (carbon monoxide and hydrogen). The synthesis gas is then introduced into a slurry bubble column where it undergoes the Fischer-Tropsch reaction. In the slurry bubble column, catalytic particles are suspended in liquid hydrocarbons. Gas phase reactants, including the synthesis gas, are then bubbled through the reactor. As the gas bubbles rise, the reactants are absorbed into the liquid and diffuse to the catalyst where they are converted to liquid hydrocarbon products.

A

The '705 patent is directed to a method of activating an essentially fresh, reduced cobalt-containing Fischer-Tropsch catalyst. According to the specification, the cobalt catalyst is incorporated into an inert support material such as an inorganic refractory oxide. Because cobalt can be dangerous to handle, the supported cobalt catalyst is then typically heated in air to form an inactive cobalt oxide. The cobalt oxide must then be "reduced" to active cobalt metal before it is introduced into the slurry bubble column reactor. That is conventionally done by treating the cobalt oxide with hydrogen or hydrogen-containing gas at elevated temperatures or pressures. The specification teaches that the essentially fresh, reduced cobalt catalyst can then be "super activated" in a way that accelerates the conversion of the natural gas components into liquid hydrocarbons if the cobalt is further treated with hydrogen or a hydrogen-containing gas after the catalyst is introduced into the slurry bubble column reactor. The super-activation procedure is conducted either before synthesis gas is introduced into the reactor or shortly after the synthesis reaction has begun. The '705 patent states that the claimed treatment method increases the relative catalyst productivity in the Fischer-Tropsch reaction by at least 30%. '705 patent, col. 1, ll. 59-64. The '705 patent claims:

1. A method for activating an essentially fresh, reduced cobalt containing Fischer-Tropsch catalyst which comprises treating the catalyst with hydrogen or a hydrogen containing gas in the presence of hydrocarbon liquids for a period sufficient to increase substantially the initial catalyst productivity.

All other claims of the '705 patent depend from claim 1.

In its motion for summary judgment, the government asserted that the terms "for a period sufficient" and "to increase substantially" in claim 1 of the '705 patent were both indefinite. The Court of Federal Claims agreed with the government's submission and therefore held the '705 patent invalid.

B

The '982 patent teaches a method for optimally operating a slurry bubble column using a supported cobalt catalyst to produce hydrocarbon products at an increased rate. This result is achieved by controlling certain reactor variables. Claim 1 of the '982 patent recites:

1. A method for optimally operating a large diameter three phase (gas, liquid, solid) slurry bubble column having a diameter greater than 15 cm for Fischer-Tropsch synthesis over a supported cobalt catalyst in which solid particles are fluidized in the liquid phase by bubbles of the gas phase, comprising:

(a) injecting the gas phase into said column at an average gas velocity along said column, U_g % 2 cm/sec, such that the flow regime is in the substantial absence of slug flow;

(b) fluidizing the solid supported cobalt catalyst particles of average diameter, d_p % 5 m, to the height, H % 3m, of the expanded liquid in the column by operating with a catalyst settling velocity, Us, and dispersion coefficient, D, such that

                      0.5(Us - UL  3 m
                

___

                         = H 
                

where

                     Us = 1 dp2 Ps - P1 gf(Cp), where dp > 5m
                      ___ ______
                      18    
                

and

(c) maintaining plug flow in said column by operating with a gas phase velocity, U_g, expanded liquid height, H, and dispersion coefficient, D, such that

U_g = 0.2D/H, where H % 3m, U_g % 2 cm/sec

wherein

                Ps = effective density of the particles 
                P1 = density of the liquid 
                u= viscosity of the liquid 
                f(Cp) = hindered settling function 
                    = volume fraction of solids in the 
                       slurry (liquid plus solids) 
                L = liquid velocity along the column 
                H = height of the expanded liquid in said reactor 
                g = gravitational constant 
                dp = diameter of particles 
                m = meters. 
                

All other claims of the '982 patent depend from claim 1.

On the government's motion for summary judgment, the Court of Federal Claims found that four of the terms in claim 1 of the '982 patent were indefinite and that claim 1 and all the dependent claims were therefore invalid. The four terms that the court found to be indefinite are: "substantial absence of slug flow," "fluidizing the . . . catalyst particles . . . to the height, H % 3m," "particles of average diameter," and the term "U_L" as used in the first formula set out in claim 1.

II

A

Section 112 paragraph 2 of the Patent Act requires that a patent specification conclude with one or more claims "particularly pointing out and distinctly claiming subject matter which the applicant regards as his invention." 35 U.S.C. 112, 2. We have stated the standard for assessing whether a patent claim is sufficiently definite to satisfy the statutory requirement as follows: If one skilled in the art would understand the bounds of the claim when read in light of the specification, then the claim satisfies section 112 paragraph 2. Miles Labs., Inc. v. Shandon, Inc., 997 F.2d 870, 875, 27 USPQ2d 1123, 1126 (Fed. Cir. 1993).

While that standard is easy to state, it has not always proved easy to apply. The Supreme Court explained the reason underlying the indefiniteness doctrine 60 years ago in United Carbon Co. v. Binney & Smith Co., 317 U.S. 228, 236, 55 USPQ 381, 385 (1942):

A zone of uncertainty which enterprise and experimentation may enter only at the risk of infringement claims would discourage invention only a little less than unequivocal foreclosure of the field. Moreover, the claims must be reasonably clear-cut to enable courts to determine whether novelty and invention are genuine.

In determining whether that standard is met, i.e., whether "the claims at issue [are] sufficiently precise to permit a potential competitor to determine whether or not he is infringing," Morton Int'l, Inc. v. Cardinal Chem. Co., 5 F.3d 1464, 1470, 28 USPQ2d 1190, 1195 (Fed. Cir. 1993), we have not held that a claim is indefinite merely because it poses a difficult issue of claim construction. We engage in claim construction every day, and cases frequently present close questions of claim construction on which expert witnesses, trial courts, and even the judges of this court may disagree. Under a broad concept of indefiniteness, all but the clearest claim construction issues could be regarded as giving rise to invalidating indefiniteness in the claims at issue. But we have not adopted that approach to the law of indefiniteness. We have not insisted that claims be plain on their face in order to avoid condemnation for indefiniteness; rather, what we have asked is that the claims be amenable to construction, however difficult that task may be. If a claim is insolubly ambiguous, and no narrowing construction can properly be adopted, we have held the claim indefinite. If the meaning of the claim is discernible, even though the task may be formidable and the conclusion may be one over which reasonable persons will disagree, we have held the claim sufficiently clear to avoid invalidity on indefiniteness grounds. See, e.g., Modine Mfg. Co. v. U.S. Int'l Trade Comm'n, 75 F.3d 1545, 1557, 37 USPQ2d 1609, 1617 (Fed. Cir. 1996) (rejecting indefiniteness argument after construing claims; stating that "when claims are amenable to more...