Patent’s Non-Standard Use of “Fractionation” Limits Scope of the Claims

federal-circuit-distanceDavid Netzer Consulting Eng’r LLC v. Shell Oil Co. (Fed. Cir. May 27, 2016) (Before Lourie, Taranto, and Prost, CJ.) (Opinion for the court, Lourie, J.) Click Here for a copy of the opinion.

Netzer sued Shell Oil for infringement of a patent which claims a process for the coproduction of ethylene and purified benzene from refinery mixtures.  The parties disputed whether Shell’s process included “fractionating” gasoline, as claimed, to produce a substance comprising at least 80% benzene.  Shell used a solubility-based extraction process to obtain 99.9% pure benzene.  Shell argued that the patent specification defined “fractionation” as a distillation-based process, and Shell’s solubility-based process did not infringe.  Netzer claimed that “fractionation” referred to any process to separate chemical mixtures into fractions.  The district court granted summary judgment of non-infringement without addressing the claim construction.  Netzer appealed.  In the absence of a holding on claim construction, the Federal Circuit assumed from the judgment that the district court determined that “fractionating” referred only to distillation-based processes. The Federal Circuit affirmed both the implied claim construction and the summary judgment of non-infringement.

The Court found that “fractionation” referred only to distillation-based techniques.  The specification’s use of the term “fractionation” controlled even if the definition was idiosyncratic.  By that standard, the Court found that “fractionation” did not encompass solubility-based techniques.  The specification identified the limits of “conventional fractionation” which were only limits of “conventional distillation,” and no other fractionation techniques known in the art were mentioned.  Therefore, the specification equated “conventional fractionation” and “conventional distillation.”  More broadly, this demonstrated that the specification equated the terms “fractionation” and “distillation.”  This finding was further supported by the repeated and consistent use of the term “fractionation” in discussion of processes to separate mixtures by distillation.

The specification further reinforced this finding by comparing solubility-based processes and fractionation.  For example, the specification noted that “conventional methods” of solubility based extraction can create 99.9% pure benzene.  However, the specification had previously indicated “conventional fractionation” is unable to create such a pure product.  If “conventional fractionation” is unable to produce such a pure product, then these “conventional methods” could not be “conventional fractionation” and thus solubility based methods were not included in the term “fractionation.”  Further, the patent identified demand for this process arising from decreased need for costly 99.9% pure benzene that would be produced by solubility based methods.  In doing so, the patent noted that the assumed impurities of the “present invention” would be acceptable.  The Court held that since these impurities were not present in the “conventional method,” that method was specifically disclaimed from the “present invention.”


Netzer argued that the presence of a hydrotreating step prior to a refinery mixture’s entry into two distillation columns demonstrated that fractionation was not defined by the specification as only a distillation-based separation.  The court rejected this argument, since the hydrotreating did not actually cause separation of any kind.  Netzer also argued that the phrase “conventional fractionation in a distillation column” would be redundant if “fractionation” and “distillation” were identical terms.  The Court disagreed noting that conventional fractionation identifies the type of process (distillation) but not the specific tools used for the distillation.  The Court did not consider extrinsic evidence in light of what it considered unambiguous intrinsic evidence.

Alternatively, Netzer argued that even under the district court’s construction, Shell was still infringing since its process had a distillation step before it began a solubility-based extraction.  The Court disagreed, as Shell’s process only used distillation to purify the benzene to 57% as opposed to the at least 80% claimed by the patent.  Furthermore, the Court held that disclaiming “conventional methods” of solubility-based extraction precluded Netzer from then claiming literal infringement or infringement under the doctrine of equivalents.  Nor, did the Court think any reasonable jury would find that the accused process performs substantially the same function in substantially the same way to obtain substantially the same result.  For these reasons, the Federal Circuit affirmed the grant of summary judgment of non-infringement.



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