PTAB

IPR2025-01454

Topsoe, Inc. v. Casale SA

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1. Case Identification

2. Patent Overview

  • Title: Process for Synthesis of Ammonia
  • Brief Description: The ’168 patent discloses a process for synthesizing ammonia from natural gas. The process involves converting natural gas into synthesis gas (syngas) in a conversion section that includes a pre-reformer and an autothermal reformer (ATR) but lacks a primary reformer, then splitting the resulting CO2-depleted syngas into a fuel fraction and a process gas fraction of the same composition.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1, 5, 6, and 10 under 35 U.S.C. § 102 by 2007 IFA

  • Prior Art Relied Upon: 2007 IFA (a presentation from an International Fertilizer Association conference).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the 2007 IFA reference explicitly discloses every limitation of independent claim 1 through its process flow diagram. The diagram shows a process for ammonia synthesis that converts desulphurized natural gas using a pre-reformer and an ATR, without an intermediate primary reformer. The reference further illustrates treatment of the resulting syngas (shift reaction, CO2 removal) and a subsequent split of the CO2-depleted stream into an "H2 Fuel" stream and an "Ammonia Syngas" stream. Petitioner asserted these streams have the same composition as they branch from a single point without intervening treatment. For dependent claims, 2007 IFA also discloses a methanator and nitrogen addition (claim 5) downstream of the split, thereby satisfying the limitation of claim 6.
    • Key Aspects: Petitioner contended that the key features the Examiner relied upon for allowance during prosecution—the specific reformer configuration and the "same composition" of the split streams—are directly taught by 2007 IFA, a reference not previously considered.

Ground 2: Anticipation/Obviousness of Claims 1, 3-4, 8-10, and 18 under 35 U.S.C. §§ 102/103 by Rytter

  • Prior Art Relied Upon: Rytter (Patent 6,809,121).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted Rytter anticipates or renders obvious the challenged claims by disclosing a syngas production process applicable to ammonia synthesis. Rytter teaches the claimed conversion section with a pre-reformer and an ATR but no primary reformer. It also teaches syngas treatment and splitting a CO2-depleted H2-containing stream for use as both fuel and for synthesis. Rytter’s disclosure of using "at least 5%" of the stream for synthesis implies the remaining portion (up to 95%) is available for fuel, which Petitioner argued discloses the fuel fraction ranges of claims 3-4. Furthermore, Rytter’s teaching of using "substantially pure O2" was argued to disclose the oxygen concentration levels of claims 8-9.
    • Motivation to Combine (for obviousness elements): For any limitations deemed not explicitly disclosed, the motivation would be to apply Rytter's known parameters to optimize a standard syngas process for energy efficiency and reduced carbon emissions, a well-known goal in the art.
    • Expectation of Success: A POSITA would have expected success in applying Rytter's teachings because they relate to well-understood principles of syngas production and plant optimization.

Ground 3: Obviousness of Claims 1, 3-4, 8-9, 10, and 18 under 35 U.S.C. § 103 over Fjellhaug in view of Rytter

  • Prior Art Relied Upon: Fjellhaug (Patent 6,505,467) and Rytter (Patent 6,809,121).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued Fjellhaug provides the basic process framework for claim 1, including a pre-reformer and ATR configuration for ammonia synthesis, syngas treatment, and splitting the syngas into fuel and process streams. Rytter was cited to supply specific operational parameters not explicitly detailed in Fjellhaug. Specifically, Rytter teaches using oxygen or oxygen-enriched air in the ATR and provides explicit ranges for fuel fraction splits and oxygen concentrations that satisfy claims 3-4 and 8-9.
    • Motivation to Combine: A POSITA would combine Fjellhaug with Rytter to incorporate well-known design choices for optimizing an ATR-based syngas process. A POSITA would modify Fjellhaug's air-driven ATR to use oxygen-enriched air as taught by Rytter, a known method to improve efficiency. It would have been obvious to apply Rytter's known operating ranges for fuel split and oxygen levels to the analogous process in Fjellhaug.
    • Expectation of Success: Success would be expected, as both references concern analogous syngas production technologies with substantial overlap, making the combination of features predictable and yielding no unexpected results.
  • Additional Grounds: Petitioner asserted numerous other challenges, including anticipation of various claims by 2007 IFA, Rytter, or Fjellhaug alone. Additional obviousness grounds combined these primary references with [Price](https://ai-lab.exparte.com/case/ptab/IPR2025-01454/doc/1011) (Application # 2002/0143219), [Ji](https://ai-lab.exparte.com/case/ptab/IPR2025-01454/doc/1012) (Patent 8,309,617), and [Licht](https://ai-lab.exparte.com/case/ptab/IPR2025-01454/doc/1009) (Patent 8,137,422) to teach limitations related to further purification, purge gas recycling, and trim fuel use, respectively.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued against discretionary denial under the Fintiv factors. The petition noted that a co-pending district court case ([Topsoe, Inc. v. Casale SA](https://ai-lab.exparte.com/case/ptab/IPR2025-01454)) is in its earliest stages, with no scheduling order entered and no trial date set. This suggests the IPR would conclude well before a potential district court trial, weighing against discretionary denial of institution.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-11 and 17-19 of Patent 11,286,168 as unpatentable.