PTAB

IPR2014-01558

Volkswagen Group Of America Inc v. EmeraChem Holdings LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Regeneration of Catalyst/Absorber
  • Brief Description: The ’758 patent discloses a method for regenerating a devitalized catalyst/absorber used to remove nitrogen oxides (NOx) from a combustion engine's exhaust stream. The method involves passing a regeneration gas, containing a reducing agent and an inert carrier gas, over the devitalized catalyst/absorber to restore its activity.

3. Grounds for Unpatentability

Ground 1: Anticipation by Saito - Claims 1-9, 11-14, 16, and 20 are anticipated by Saito under 35 U.S.C. §102(b).

  • Prior Art Relied Upon: Saito (Japanese Patent Publication 62-106826).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Saito disclosed all elements of the challenged claims. Saito taught a method for regenerating a catalyst used to remove NOx from diesel exhaust by using a gaseous reducing agent. This catalyst comprised platinum and barium oxide disposed on a high surface area alumina carrier. The regeneration process used reducing agents like hydrogen and carbon monoxide, which could be diluted in an inert gas such as nitrogen, at specified temperatures and space velocities that fall within the claimed ranges.
    • Key Aspects: A central contention was that Saito’s disclosure of a barium oxide absorbent inherently meets the claim limitation requiring a "carbonate." Petitioner asserted that a person of ordinary skill in the art (POSITA) would have known that barium oxide necessarily converts to barium carbonate when exposed to engine exhaust containing carbon dioxide, a condition disclosed by Saito.

Ground 2: Anticipation by Hirota - Claims 1, 2, 4-6, 9, 11, and 12 are anticipated by Hirota under 35 U.S.C. §102(e).

  • Prior Art Relied Upon: Hirota (Patent 5,406,790).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended Hirota disclosed every limitation of the challenged claims. Hirota taught a catalytic NOx absorbent comprising platinum and barium oxide on an alumina support for treating diesel exhaust. The absorbent is regenerated by supplying a reducing agent (e.g., carbon monoxide, hydrogen) to release and reduce the absorbed NOx. Petitioner argued that the nitrogen present in the engine exhaust during the disclosed "rich" operating conditions constituted the claimed "inert carrier gas."
    • Key Aspects: Similar to the Saito ground, this argument relied on the inherent disclosure of a carbonate absorber. Petitioner argued that the barium oxide in Hirota's system would inevitably convert to barium carbonate in the presence of carbon dioxide from the exhaust, thereby anticipating the claims.

Ground 3: Obviousness over Campbell, Hirota/Saito, and Stiles - Claims 1-14 and 16-20 are obvious over the combination of Campbell and either Hirota or Saito, in view of Stiles.

  • Prior Art Relied Upon: Campbell (Patent 5,451,558), Hirota (Patent 5,406,790) or Saito (Japanese Patent Publication 62-106826), and Stiles (Patent 5,362,463).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Campbell disclosed the specific catalyst/absorber structure claimed in the ’758 patent, namely a platinum catalyst on a support coated with an alkali or alkaline earth carbonate. However, Campbell taught that a saturated absorber should be physically replaced rather than regenerated in-situ. Hirota and Saito, in contrast, taught the in-situ regeneration of similar NOx absorbents using reducing gases (hydrogen, carbon monoxide).
    • Motivation to Combine: Petitioner argued Stiles provided the motivation to combine these references. Stiles disclosed that a potassium carbonate adsorbent (a species expressly disclosed in Campbell) could be repeatedly regenerated in-situ by passing a reducing agent like hydrogen over it. A POSITA, seeking to improve upon Campbell's disposable system, would have been motivated by Stiles to apply the known in-situ regeneration techniques from Hirota or Saito to Campbell’s known catalyst/absorber composition.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success because the combination involved applying a known regeneration technique to a known catalyst composition to achieve the predictable result of improved reusability without loss of effectiveness, as taught by Stiles.

4. Key Claim Construction Positions

  • "high surface area": Petitioner proposed this term be construed as having a surface area of at least 50 square meters per gram. This construction was based on the disclosure of the commonly assigned Campbell ’558 patent, which is incorporated by reference in its entirety into the ’758 patent.
  • "inert": Petitioner argued this term should be construed according to its definition in the ’758 patent specification, which provides "nitrogen, helium, argon or steam" as exemplary inert carrier gases.

5. Key Technical Contentions (Beyond Claim Construction)

  • Inherent Formation of Carbonate: A core technical argument underpinning the anticipation grounds (Saito and Hirota) was that the disclosure of a barium oxide (BaO) absorbent inherently satisfies the claim limitation of a "carbonate" absorber. Petitioner contended that in the disclosed environment of an internal combustion engine exhaust stream, which contains carbon dioxide (CO2), BaO would necessarily and inevitably react to form barium carbonate. Therefore, even if the prior art did not explicitly name a "carbonate," its presence was an inherent property of the disclosed system.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-14 and 16-20 of the ’758 patent as unpatentable.