David Netzer Consulting v. Shell Oil Company , 824 F.3d 989 ( 2016 )


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  •   United States Court of Appeals
    for the Federal Circuit
    ______________________
    DAVID NETZER CONSULTING ENGINEER LLC,
    Plaintiff-Appellant
    v.
    SHELL OIL COMPANY, SHELL CHEMICAL LP,
    SHELL OIL PRODUCTS COMPANY LLC,
    Defendants-Appellees
    ______________________
    2015-2086
    ______________________
    Appeal from the United States District Court for the
    Southern District of Texas in No. 4:14-cv-00166, Judge
    Lynn N. Hughes.
    ______________________
    Decided: May 27, 2016
    ______________________
    ANTHONY MATTHEW GARZA, Charhon Callahan Robson
    & Garza, P.C., Dallas, TX, argued for plaintiff-appellant.
    Also represented by STEVEN CHASE CALLAHAN.
    KATHLEEN M. SULLIVAN, Quinn Emanuel Urquhart &
    Sullivan, LLP, New York, NY, argued for defendants-
    appellees. Also represented by KEVIN ALEXANDER SMITH,
    San Francisco, CA; JOSHUA L. SOHN, Washington, DC;
    CHARLES BRUCE WALKER, JR., Norton Rose Fulbright US
    LLP, Houston, TX; JAYME PARTRIDGE, Patterson & Sheri-
    dan LLP, Houston, TX.
    2                        DAVID NETZER v. SHELL OIL COMPANY
    ______________________
    Before PROST, Chief Judge, LOURIE and TARANTO,
    Circuit Judges.
    LOURIE, Circuit Judge.
    David Netzer Consulting Engineer LLC (“Netzer”) *
    appeals from the decision of the United States District
    Court for the Southern District of Texas granting sum-
    mary judgment of noninfringement of the asserted claims
    of U.S. Patent 6,677,496 (“the ’496 patent”). David Netzer
    Consulting Eng’r LLC v. Shell Oil Co., No. 4:14-cv-00166,
    ECF No. 45 (S.D. Tex. Aug. 26, 2015) (“Decision”). For the
    reasons that follow, we affirm.
    BACKGROUND
    Netzer owns the ’496 patent, entitled “Process for the
    Coproduction of Benzene from Refinery Sources and
    Ethylene by Steam Cracking,” which describes a process
    for the coproduction of ethylene and purified benzene
    from refinery mixtures. Claim 1, the sole independent
    claim, reads as follows:
    1. A process for the coproduction of ethylene and
    purified benzene comprising:
    providing a first mixture comprising benzene,
    toluene, and one or more C6 to C7 non-
    aromatics;
    separating the majority of the benzene and the
    one or more C6 to C7 non-aromatics from the
    majority of the toluene to form a second
    mixture containing at least a portion of the
    *  As indicated infra, in March 2014, David Netzer
    Consulting Engineer LLC changed its name to David
    Netzer – Petrochemicals Consultant LLC.
    DAVID NETZER v. SHELL OIL COMPANY                          3
    benzene and at least a portion of the one or
    more C6 to C7 non-aromatics, wherein the
    second mixture is substantially free of hy-
    drocarbons having more than nine carbons;
    introducing at least a portion of the second
    mixture to a cracker and thereafter cracking
    at least about 80% of the C6 to C7 non-
    aromatics in the portion of the second mix-
    ture that has been introduced to the cracker
    while maintaining essentially no cracking of
    benzene to produce a cracked product con-
    taining ethylene, propylene and pyrolysis
    gasoline comprising olefins, di-olefins and
    benzene; and
    fractionating the pyrolysis gasoline to form a
    purified benzene product comprising at least
    about 80 wt % benzene.
    ’496 patent col. 7 ll. 11–32 (emphases added).
    The claimed process thus requires four steps: (1) pro-
    viding a mixture containing benzene, toluene, and C6–C7
    non-aromatic hydrocarbons; (2) separating most of the
    benzene and C6–C7 non-aromatic hydrocarbons from most
    of the toluene; (3) introducing the benzene-rich stream
    into a cracker, i.e., a reactor that breaks down long-chain
    hydrocarbons to short-chain hydrocarbons, and then
    cracking the C6–C7 non-aromatic hydrocarbons to produce
    ethylene and pyrolysis gasoline; and (4) “fractionating the
    pyrolysis gasoline to form a purified benzene product
    comprising at least about 80 wt % of benzene” (“the frac-
    tionating step”).
    On January 23, 2014, David Netzer, the sole inventor
    of the ’496 patent, assigned the patent to Netzer, a limited
    liability company newly formed under Texas law. J.A. 85
    (assignment); J.A. 81–83 (Certificate of Filing issued by
    the Secretary of State). The next day, Netzer sued Shell
    4                        DAVID NETZER v. SHELL OIL COMPANY
    Oil Company, Shell Chemical LP, and Shell Oil Products
    Company LLC (collectively, “Shell”) in the United States
    District Court for the Southern District of Texas, alleging
    that Shell infringed the ’496 patent. Shortly thereafter,
    the State of Texas requested that Netzer remove the word
    “Engineer” from its name.       In March 2014, Netzer
    changed its name from David Netzer Consulting Engineer
    LLC to David Netzer – Petrochemicals Consultant LLC
    through a Certificate of Correction. J.A. 78–79, 87–88.
    Meanwhile, Shell answered and counterclaimed for a
    declaratory judgment of noninfringement and invalidity
    in the district court.
    Shell then moved for summary judgment of non-
    infringement. Shell argued that the term “fractionating”
    should be construed to mean “conventional distillation,
    i.e., separating compounds based on difference in their
    boiling points,” which excludes extraction, i.e., separating
    compounds based on solubility differences. Shell argued
    that the patentee disclaimed extraction in the specifica-
    tion and prosecution history. According to Shell, its
    accused process does not meet the fractionating step
    because it uses extraction—more specifically, the Sul-
    folane process developed by Shell in the 1960s—to form a
    benzene product with 99.9% purity. Netzer responded
    that “fractionating” should be construed to mean “separat-
    ing a chemical mixture into fractions, no matter the
    process units used.” Examples of process units, according
    to Netzer, include distillation columns (for separating
    chemicals based on differences in boiling points), extrac-
    tors (for separating chemicals based on solubility differ-
    ences), and hydrotreaters (for hydrogenating unsaturated
    hydrocarbons, such as olefins). Netzer also argued that
    Shell infringes literally under either construction, and
    that Shell also infringes under the doctrine of equivalents.
    The district court granted summary judgment of non-
    infringement. The court did not formally construe the
    claims, but, rather, implicitly agreed with Shell that
    DAVID NETZER v. SHELL OIL COMPANY                           5
    “fractionating” does not include extraction. The court
    found no literal infringement, reasoning that “Netzer’s
    method does not include extraction and does not yield
    benzene of 99.9% purity” and that “[t]o infringe, Shell
    would have to eliminate the extraction step and still
    produce benzene purified to at least 80%.” Decision at 2.
    The court also found no infringement under the doctrine
    of equivalents because Netzer is barred by “specific exclu-
    sion, prosecution-history estoppel, and prior art.” 
    Id. at 3.
         The district court then entered final judgment in favor
    of Shell. David Netzer Consulting Eng’r LLC v. Shell Oil
    Co., No. 4:14-cv-00166, ECF No. 46 (S.D. Tex. Aug. 26,
    2015). Netzer timely appealed to this court. However,
    because Shell’s counterclaims remained pending in the
    district court, this court granted the parties’ joint motion
    for a limited remand. On that limited remand, the dis-
    trict court dismissed Shell’s declaratory judgment coun-
    terclaims without prejudice and then entered an amended
    final judgment, thus disposing of all claims and counter-
    claims. David Netzer Consulting Eng’r LLC v. Shell Oil
    Co., No. 4:14-cv-00166, ECF No. 56 (S.D. Tex. Mar. 31,
    2016). Netzer then filed a new notice of appeal, and its
    appeal was reinstated in this court. We have jurisdiction
    under 28 U.S.C. § 1295(a)(1).
    DISCUSSION
    I
    Before we reach the merits of Netzer’s appeal, Netzer
    asks us to confirm that it has standing to maintain this
    action. According to Netzer, on January 24, 2014, at the
    inception of the lawsuit, an entity known as David Netzer
    Consulting Engineer LLC held enforceable title to the
    ’496 patent pursuant to the January 23, 2014 assignment,
    and thus had standing to sue. Netzer argues that the
    March 2014 name change did not retroactively invalidate
    the January 2014 assignment under Texas law. The
    district court did not question Netzer’s standing.
    6                        DAVID NETZER v. SHELL OIL COMPANY
    We agree with Netzer that it has standing to bring
    and maintain this action. At the inception of the lawsuit,
    the ’496 patent was assigned to the plaintiff entity, then
    named David Netzer Consulting Engineer LLC. Although
    that entity later changed its name to David Netzer –
    Petrochemicals Consultant LLC as required by Texas law,
    that name change did not undo the January 23, 2014
    transfer of patent ownership. The patent was owned by
    the same company, under its new name. We therefore
    conclude that Netzer, as the owner of the ’496 patent as of
    January 24, 2014, has standing to maintain this action.
    II
    We turn now to the merits of Netzer’s appeal. When
    reviewing a district court’s grant of summary judgment,
    we apply the law of the regional circuit in which the
    district court sits, here, the law of the Fifth Circuit. Teva
    Pharm. Indus. Ltd. v. AstraZeneca Pharm. LP, 
    661 F.3d 1378
    , 1381 (Fed. Cir. 2011). The Fifth Circuit reviews a
    district court’s summary judgment decision de novo,
    applying the same standard used by the district court.
    United States v. Caremark, Inc., 
    634 F.3d 808
    , 814 (5th
    Cir. 2011). Summary judgment is appropriate when,
    drawing all justifiable inferences in the nonmovant’s
    favor, “there is no genuine dispute as to any material fact
    and the movant is entitled to judgment as a matter of
    law.” Fed. R. Civ. P. 56(a); Anderson v. Liberty Lobby,
    Inc., 
    477 U.S. 242
    , 247–48 (1986).
    To determine infringement, a court first construes the
    scope and meaning of the asserted patent claims, and
    then compares the construed claims to the accused pro-
    duct or process. Absolute Software, Inc. v. Stealth Signal,
    Inc., 
    659 F.3d 1121
    , 1129 (Fed. Cir. 2011). “The proper
    construction of a patent’s claims is an issue of Federal
    Circuit law.” 
    Id. We review
    a district court’s ultimate
    claim constructions de novo and any underlying factual
    determinations involving extrinsic evidence for clear
    DAVID NETZER v. SHELL OIL COMPANY                          7
    error. Teva Pharm. U.S.A., Inc. v. Sandoz, Inc., 
    135 S. Ct. 831
    , 841–42 (2015).
    Here, the district court did not make any factual find-
    ings to support any claim construction. See Appellant’s
    Br. 21. Its claim construction was implicit in its decision
    of noninfringement. Because the intrinsic record alone
    determines the proper construction in this case, we are
    able to conduct our review adequately and we do so de
    novo. See Shire Dev., LLC v. Watson Pharm., Inc., 
    787 F.3d 1359
    , 1364, 1368 (Fed. Cir. 2015) (citing Teva, 135 S.
    Ct. at 840–42).
    Infringement is a question of fact. Absolute 
    Software, 659 F.3d at 1129
    –30. “On appeal from a grant of sum-
    mary judgment of non-infringement, we determine
    whether, after resolving reasonable factual inferences in
    favor of the patentee, the district court correctly conclud-
    ed that no reasonable jury could find infringement.” 
    Id. A. Claim
    Construction
    The words of a claim “are generally given their ordi-
    nary and customary meaning” as understood by a person
    of ordinary skill in the art at the time of the invention.
    Phillips v. AWH Corp., 
    415 F.3d 1303
    , 1312–13 (Fed. Cir.
    2005) (en banc). Because that meaning is “often not
    immediately apparent, and because patentees frequently
    use terms idiosyncratically,” the court looks to the intrin-
    sic record, including “the words of the claims themselves,
    the remainder of the specification, [and] the prosecution
    history,” as well as to extrinsic evidence when appro-
    priate, to construe a disputed claim term. 
    Id. at 1314,
    1319. “[W]hile extrinsic evidence can shed useful light on
    the relevant art, we have explained that it is less signifi-
    cant than the intrinsic record in determining the legally
    operative meaning of claim language.” 
    Id. at 1317
    (quota-
    tion marks omitted).
    8                          DAVID NETZER v. SHELL OIL COMPANY
    Because a patent is a fully integrated written instru-
    ment, we have long emphasized the importance of the
    specification in claim construction. 
    Id. at 1315
    (explain-
    ing that the specification “is the single best guide to the
    meaning of a disputed term”) (quoting Vitronics Corp. v.
    Conceptronic, Inc., 
    90 F.3d 1576
    , 1582 (Fed. Cir. 1996)).
    Thus, if the specification reveals a special definition given
    to a claim term by the inventor, then the inventor’s lexi-
    cography governs, even if it differs from the term’s ordi-
    nary meaning. 
    Id. at 1316.
    Likewise, if the specification
    reveals an intentional disclaimer or disavowal of claim
    scope by the inventor, then the inventor’s intention as
    expressed in the specification is regarded as dispositive.
    
    Id. We have
    found disavowal or disclaimer based on clear
    and unmistakable statement, such as “the present inven-
    tion includes . . . ,” “the present invention is . . . ,” and “all
    embodiments of the present invention are . . . .” Pacing
    Techs., LLC v. Garmin Int’l, Inc., 
    778 F.3d 1021
    , 1024
    (Fed. Cir. 2015).
    Netzer argues that “fractionating” means separating a
    mixture into fractions, no matter what processes are used
    to do so. According to Netzer, both the intrinsic record
    and the extrinsic evidence suggest that fractionation
    includes any method of separation, not limited to distilla-
    tion. Netzer contends that the patentee did not disclaim
    extraction by merely characterizing it as expensive in the
    specification. Netzer additionally argues that the claim
    only sets a lower limit on benzene purity, viz., “at least
    about 80 wt %,” and thus does not exclude extraction,
    which produces highly pure benzene. Netzer lastly argues
    that “fractionating” ought to be construed to encompass
    the disclosed preferred embodiment, so as to allow the
    pyrolysis gasoline to pass through (a) more than one
    process unit (in the preferred embodiment, a hydrotreater
    and then two distillation columns), and (b) process units
    that do not separate chemicals, such as a hydrotreater.
    DAVID NETZER v. SHELL OIL COMPANY                          9
    Shell responds that “fractionating” should be con-
    strued here to mean separating compounds based on
    differences in boiling points, not generic “separating” by
    any means. Shell argues that the intrinsic record compels
    that construction, which cannot be altered by conflicting
    extrinsic evidence. In particular, Shell contends that the
    patent specification uses “fractionating” or “fractionation”
    to describe separating compounds based on boiling points.
    According to Shell, the patentee also disclaimed extrac-
    tion in the specification by distinguishing it from “frac-
    tionation” and by explaining that the claimed invention
    was driven by a shift in market demand that no longer
    required high purity benzene produced by extraction, such
    as by the Sulfolane process.
    We agree with Shell that the claim term “fractionat-
    ing” in this patent means separating compounds based on
    differences in boiling points, i.e., distillation, which ex-
    cludes extraction, such as in the Sulfolane process. The
    specification repeatedly and consistently uses “fractionat-
    ing” or “fractionation” to describe separating petrochemi-
    cals based on boiling point differentials.         Moreover,
    importantly, the patentee made clear and unmistakable
    statements in the intrinsic record, distinguishing the
    claimed invention from and disclaiming conventional
    extraction methods that produce 99.9% pure benzene.
    Specifically, the ’496 patent describes an “azeotrope”
    problem. An azeotrope is a mixture of two or more com-
    pounds that has a uniform boiling point; its components
    vaporize together as a mixture and thus cannot be easily
    separated from each other by distillation. J.A. 273. The
    specification explains that certain C6–C7 non-aromatic
    hydrocarbons form azeotropes with benzene, making it
    “impossible” to separate benzene from that mixture by
    “conventional fractionation.” ’496 patent col. 2 ll. 17–20.
    The specification then discusses this issue in further
    detail and refers to the azeotrope problem as “the conven-
    tional fractionation issue.” 
    Id. col. 3
    ll. 18–35. Thus, the
    10                          DAVID NETZER v. SHELL OIL COMPANY
    patentee used “conventional fractionation” to refer to
    conventional distillation, i.e., a conventional method that
    separates compounds based on differences in their boiling
    points.
    Elsewhere, the specification repeatedly and consist-
    ently uses the term “fractionation,” whether modified by
    an adjective or not, in connection with temperature or
    boiling points. See, e.g., 
    id. col. 2
    ll. 58–59 (“naphtha
    resulting from crude oil fractionation has a boiling range
    of 100 to 350º F”); 
    id. col. 2
    ll. 62–63 (“naphtha undergoes
    further fractionation to separate a cut point of below
    200º F, light naphtha”); 
    id. fig.1 &
    col. 5 ll. 9–14 (describ-
    ing a “Fractionation & PSA Refrigeration” unit in Figure
    1, where ethylene, a more volatile compound, is recovered
    by “refrigerated fractionation,” and propylene and C4 mix,
    less volatile compounds, are each recovered by “warm
    fractionation”); 
    id. col. 5
    ll. 24–34 (stating that the hydro-
    treated pyrolysis gasoline undergoes “fractionation” for
    benzene recovery in two distillation columns). Although
    the specification uses the word “distillation” only in some
    instances, 
    id. col. 2
    ll. 23, 60; 
    id. col. 3,
    ll. 10–11; 
    id. col. 8,
    ll. 12–13, the repeated and consistent references to “frac-
    tionation” in the context of boiling-point-based separation
    indicate that the patentee uses “fractionation” to refer to
    distillation specifically, not to generic “separation.”
    Importantly, the patentee distinguished conventional
    extraction from fractionation in the specification, indicat-
    ing that “fractionation” does not include conventional
    extraction.     After identifying the azeotrope problem
    encountered by “conventional fractionation,” 
    id. col. 2
    ll. 17–20, the specification explains that “[t]he conven-
    tional method of benzene purification and separation from
    the above azeotropes is by aromatic extraction or extrac-
    tive distillation processes, such as [the] Sulfolane [pro-
    cess],” 
    id. col. 2
    ll. 21–25 (emphases added), which
    produces >99.9% pure benzene, 
    id. col. 2
    l. 28. Thus,
    according to the patentee, conventional extraction and
    DAVID NETZER v. SHELL OIL COMPANY                         11
    conventional fractionation are different methods. Unlike
    conventional fractionation, conventional extraction—
    which includes the Sulfolane process—can successfully
    remove non-aromatic hydrocarbon azeotropes to produce
    highly pure benzene. The Sulfolane process is therefore
    conventional extraction, not “conventional fractionation.”
    The Sulfolane process was developed by Shell in the
    1960s; it is a conventional method of separation. If one
    were to adopt Netzer’s proposed construction that “frac-
    tionation” means separation by any method, then “con-
    ventional fractionation” would mean separation by any
    conventional method, which would encompass the Sul-
    folane process. That interpretation would be contrary to
    the specification.
    Furthermore, as shown by the intrinsic record, the pa-
    tentee clearly disclaimed conventional extraction, charac-
    terizing it as expensive and not required due to a shift in
    market demand, and distinguishing it from the “present
    invention.” 
    Id. col. 2
    ll. 25–28, 33–37, 44–48, 51–55. The
    specification explains that there had been a strong mar-
    ket demand for “benzene of nitration grade, about 99.9 wt
    %,” 
    id. col. 1
    l. 54, but that such high purity benzene was
    no longer required in some circumstances; rather, ben-
    zene products from the “present invention” containing
    non-aromatic impurities can be used in its place. 
    Id. col. 2
    ll. 46–48 (“the assumed non-aromatic impurities in the
    benzene, resulting from the application of the present
    invention” (emphasis added)); 
    id. col. 2
    ll. 54–55 (“This
    market shift is the major driving force behind the present
    invention.” (emphasis added)). Likewise, the patentee
    twice stated during prosecution that the claimed process
    is “particularly useful” “to produce a benzene product that
    need not have a purity over 99 wt%, much less over 99.9
    wt%, as previously required.” J.A. 261, 880 (emphases
    added).
    Those clear statements indicate that the inventor con-
    templated the claimed invention to be different from
    12                       DAVID NETZER v. SHELL OIL COMPANY
    conventional extraction, which produces highly pure,
    nitration-grade 99.9% benzene. If “fractionation” were to
    include conventional extraction, then the claimed process
    would yield 99.9% pure benzene and there would not be
    significant “non-aromatic impurities . . . resulting from
    the application of the present invention.” ’496 patent col.
    2 ll. 46–48; see also 
    id. col. 3
    l. 58, col. 4 ll. 26–30 (“In
    accordance with the inventive method,” “fractionation”
    produces “close to 98 wt % benzene.”).
    To be clear, we only conclude that the patentee dis-
    claimed conventional extraction, such as the Sulfolane
    process. We recognize that the claim language only sets a
    lower limit on the purity of the benzene product, and thus
    does not preclude other unconventional distillation meth-
    ods that are capable of producing highly pure benzene.
    But in view of the disclaimer of conventional extraction in
    the publicly available intrinsic record, Netzer cannot now
    attempt to recapture the disclaimed subject matter.
    Netzer also argues that construing “fractionating” as
    distillation would improperly exclude the preferred em-
    bodiment disclosed in Figure 1 of the ’496 patent. We
    disagree. In that disclosed embodiment, the pyrolysis
    gasoline is passed through a hydrotreater, and the result-
    ing “hydrotreated pyrolysis gasoline” is then passed
    through two distillation columns to produce a benzene
    product with 98% to 99% purity. 
    Id. fig.1 &
    col. 5 ll. 21–
    26, 48–51. Contrary to Netzer’s argument, the hydro-
    treater embodiment does not compel a different meaning
    of “fractionating.” The disclosed embodiment merely adds
    a hydrotreating step—a step that does not separate the
    individual components of the pyrolysis gasoline from each
    other, but rather hydrogenates the olefins in that mix-
    ture—before the fractionating step; it does not require the
    construction of “fractionating” to include hydrotreating, or
    any process other than distillation. Notably, dependent
    claim 19 is directed to a process “further comprising” a
    DAVID NETZER v. SHELL OIL COMPANY                           13
    hydrotreating step, 
    id. col. 8
    ll. 33–35, thus showing that
    hydrotreating is not part of the fractionating step.
    Rather, the intrinsic record suggests that the patentee
    referred to the hydrotreated pyrolysis gasoline as a type
    of pyrolysis gasoline: the language of claim 1 defines
    “pyrolysis gasoline” as “comprising olefins, di-olefins and
    benzene,” 
    id. col. 7
    ll. 28–29, and the specification refers
    to the product from the hydrotreater as the “hydrotreated
    pyrolysis gasoline,” 
    id. col. 5
    l. 25, which is then distilled
    twice to form benzene with 98% to 99% purity. According-
    ly, under the proper construction of “fractionating,” the
    disclosed embodiment is within the scope of the claims.
    Netzer primarily relies on two pieces of intrinsic evi-
    dence, but neither supports its proposed construction.
    First, Netzer notes that dependent claim 11 recites “con-
    ventional fractionation in a distillation column.” 
    Id. col. 8
    ll. 9–13. Netzer argues that if fractionation means distil-
    lation, then there would be no need to state “fractionation
    in a distillation column.” We find that argument unavail-
    ing. The quoted phrase merely requires that the fraction-
    ation, or distillation, occur in a distillation column as
    opposed to in another device. Such specific, clarifying
    language does not change the meaning of fractionation.
    Second, Netzer relies on a passage in the specifica-
    tion, which states that: “Fractionation and production of
    benzene with over 75 wt % purity from reformer reactor
    effluent by conventional distillation may become difficult
    . . . .” 
    Id. col. 3
    ll. 9–11. Netzer again argues that if
    fractionation means distillation, then it does not make
    sense to say “fractionation . . . by conventional distilla-
    tion.” We disagree. Netzer has not quoted the full sen-
    tence. The omitted portion of the quoted sentence reads:
    “. . . because of the azeotrope forming characteristics of
    compounds such as dimethylpentanes, cyclohexane and
    methyl-cyclopentane.” 
    Id. col. 3
    ll. 11–13. Thus, that full
    sentence explains that the listed azeotropes make conven-
    14                       DAVID NETZER v. SHELL OIL COMPANY
    tional fractionation, i.e., conventional distillation, diffi-
    cult. To avoid that problem, one may resort to unconven-
    tional fractionation techniques, such as the claimed
    process of cracking the C6–C7 azeotropes to convert them
    to shorter chain and more volatile hydrocarbons before
    fractionation. Thus, the quoted sentence is entirely
    consistent with, and indeed supports, our construction of
    “fractionating.”
    Accordingly, the intrinsic evidence here points in only
    one direction, and requires that “fractionating” in this
    patent be construed as separating compounds based on
    differences in boiling points. The parties cite conflicting
    extrinsic evidence, which does not compel a different
    construction. As we have explained, extrinsic evidence
    may not be used to contradict claim meaning that is
    unambiguous in light of the intrinsic record. Summit 6,
    LLC v. Samsung Elecs. Co., 
    802 F.3d 1283
    , 1290 (Fed. Cir.
    2015).
    We therefore conclude that “fractionating” in the pre-
    sent patent means separating compounds based on differ-
    ences in boiling points, which excludes conventional
    extraction methods, such as the Sulfolane process.
    B. Infringement
    Netzer also argues that the district court erred in
    granting summary judgment of noninfringement. Accord-
    ing to Netzer, under its proposed construction, Shell’s
    accused process satisfies the fractionating limitation
    because Shell separates 99.9% pure benzene from pyroly-
    sis gasoline. Even under Shell’s proposed construction,
    Netzer contends, Shell still literally infringes the ’496
    patent because it directs its pyrolysis gasoline through a
    series of process units, some of which are distillation
    columns, and forms 99.9% pure benzene in the end. It is
    irrelevant that the mixture also passes through an extrac-
    tor as part of that process, according to Netzer, because
    adding an extra step to an otherwise infringing process
    DAVID NETZER v. SHELL OIL COMPANY                           15
    does not defeat a finding of infringement. Netzer addi-
    tionally argues that the district court erred in finding
    Netzer barred from relying on the doctrine of equivalents
    to prove infringement, and that the accused process
    satisfies the function-way-result test as to the “fractionat-
    ing” limitation.
    Shell responds that, under the proper construction of
    “fractionating,” i.e., distillation, or separating compounds
    based on differences in boiling points, Shell does not
    infringe the ’496 patent because it uses its own Sulfolane
    process, which uses extraction, not distillation, to form
    >80% pure benzene. More specifically, Shell explains that
    its pyrolysis gasoline is refined in multiple steps to yield a
    mixture containing about 57% benzene, far below the 80%
    required by the claims; and Shell then uses the Sulfolane
    process to remove non-aromatic impurities in that mix-
    ture to produce 99.9% pure benzene. Shell also responds
    that Netzer is barred from asserting infringement under
    the doctrine of equivalents because the patentee dis-
    claimed the Sulfolane process. Even if Netzer is not
    barred, Shell argues, the Sulfolane process does not purify
    benzene in substantially the same way as “fractionating.”
    We agree with Shell that the district court did not err
    in granting summary judgment of noninfringement.
    Shell’s process does not literally meet the fractionating
    limitation. Shell relies on conventional extraction—more
    specifically, its own Sulfolane process—to refine a mixture
    containing about 57% benzene to a benzene product of
    greater than 80% purity. As we have explained, “frac-
    tionating” means distillation; it does not include conven-
    tional extraction. Moreover, the earlier steps of the Shell
    process only refine pyrolysis gasoline to produce a 57%
    pure benzene mixture, which does not satisfy the limita-
    tion “to form a purified benzene product comprising at
    least about 80 wt % benzene.”
    16                       DAVID NETZER v. SHELL OIL COMPANY
    It is true that a method claim with the word “compris-
    ing” appearing at the beginning generally allows for
    additional, unclaimed steps in the accused process, but
    each claimed step must nevertheless be performed as
    written. Dippin’ Dots, Inc. v. Mosey, 
    476 F.3d 1337
    , 1343
    (Fed. Cir. 2007) (“[The] enumerated steps must . . . all be
    practiced as recited in the claim for a process to infringe.
    The presumption raised by the term ‘comprising’ does not
    reach into each of the six steps to render every word and
    phrase therein open-ended . . . .”). Netzer’s infringement
    theory requires rewriting the claimed step to read “frac-
    tionating the pyrolysis gasoline [and] form[ing] a purified
    benzene product” rather than “fractionating the pyrolysis
    gasoline to form a purified benzene product,” as the claim
    is written.
    We are also unpersuaded by Netzer’s argument ana-
    logizing the accused process to the preferred embodiment
    of the ’496 patent, as both process the pyrolysis gasoline
    through multiple steps and generate >80% pure benzene
    in the end. As we have explained, hydrotreating is not
    part of the fractionating step. The hydrotreating step in
    the preferred embodiment merely produces a hydrotreat-
    ed pyrolysis gasoline; it is not a step that separates the
    individual components of the pyrolysis gasoline. In the
    preferred embodiment, the hydrotreated pyrolysis gaso-
    line is distilled twice to form >80% benzene. In contrast,
    nothing in the Shell process distills pyrolysis gasoline “to
    form” >80% benzene.
    Moreover, as 
    indicated supra
    , the patentee disclaimed
    conventional extraction, including the Sulfolane process.
    Netzer cannot now assert that the claimed fractionating
    step is literally infringed by the Sulfolane process. Like-
    wise, Netzer cannot show infringement under the doctrine
    of equivalents. The disclaimer of the Sulfolane process for
    literal infringement applies equally to infringement under
    the doctrine of equivalents. SciMed Life Sys., Inc. v.
    DAVID NETZER v. SHELL OIL COMPANY                        17
    Advanced Cardiovascular Sys., Inc., 
    242 F.3d 1337
    , 1347
    (Fed. Cir. 2001).
    We agree with Shell, moreover, that no reasonable ju-
    ry would find that the accused process performs substan-
    tially the same function in substantially the same way to
    obtain substantially the same result. Warner-Jenkinson
    Co. v. Hilton Davis Chem. Co., 
    520 U.S. 17
    , 38–40 (1997).
    Shell’s Sulfolane process does not purify benzene to >80%
    purity in substantially the same way as the claimed
    process because almost all of the purification in the Sul-
    folane process is done through extraction, i.e., separating
    compounds based on solubility differences, which is
    substantially different from the claimed process of sepa-
    rating compounds based on differences in boiling points.
    Drawing all justifiable inferences in Netzer’s favor, we
    agree with Shell that Netzer cannot establish infringe-
    ment under the doctrine of equivalents in light of the
    substantial difference between the claimed process and
    the accused process.
    We therefore conclude that the district court did not
    err in granting summary judgment of noninfringement,
    either literally or under the doctrine of equivalents.
    CONCLUSION
    We have considered the remaining arguments and
    find them unpersuasive. For the foregoing reasons, we
    affirm the district court’s summary judgment of non-
    infringement.
    AFFIRMED