PTAB

IPR2025-01455

Topsoe Inc v. Casale SA

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Process for Synthesis of Ammonia from Natural Gas
  • Brief Description: The ’168 patent discloses a process for synthesizing ammonia from natural gas. The process involves converting desulphurized natural gas in a specific conversion section—comprising a pre-reformer followed by an autothermal reformer (ATR) without an intermediate primary reformer—and then splitting the resulting CO2-depleted synthesis gas into a fuel stream and a process stream for ammonia production.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1, 7, and 10 by Terrien

  • Prior Art Relied Upon: Terrien (Application # 2012/0292574).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Terrien discloses every limitation of claim 1. Terrien teaches a process for hydrogen synthesis that includes converting desulphurized natural gas in a section with a pre-reformer and an ATR, treating the resulting syngas with a shift reaction and CO2 removal, and splitting the CO2-depleted (H2-rich) stream. Critically, Terrien shows a portion of this split stream is used as fuel, and because it is a simple split, the resulting streams have the same composition. Petitioner contended that a person of ordinary skill in the art (POSITA) would understand that Terrien’s hydrogen synthesis process is a suitable front-end for an ammonia plant.
    • Key Aspects: This ground asserted that the key claim limitation added during reexamination—a pre-reformer followed by an ATR "without a primary reformer therebetween"—is explicitly disclosed by Terrien's process configuration. For dependent claims, Petitioner argued Terrien’s teaching of 100% CO2 emission elimination inherently meets the purity requirement of claim 7, and its disclosure of recycling fuel to the conversion section anticipates claim 10.

Ground 2: Obviousness of Claims 1, 2, 5-7, and 19 over Terrien in view of Price

  • Prior Art Relied Upon: Terrien (Application # 2012/0292574) and Price (Application # 2002/0143219).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Terrien provides the foundational process, including syngas generation and splitting for fuel use. To the extent any limitation is not explicitly disclosed by Terrien, Price supplies the missing element. Price was cited to explicitly teach a reforming section with a steam reformer followed by an ATR (fulfilling the "without a primary reformer" limitation) and to expressly disclose that the resulting syngas is intended for ammonia synthesis. Price also teaches further purification steps, such as pressure swing adsorption (PSA) and methanation, common in ammonia synthesis, which maps to claims 2 and 5.
    • Motivation to Combine: A POSITA would combine Terrien and Price to leverage Terrien’s efficient hydrogen production and CO2 reduction methods for the well-known application of ammonia synthesis taught by Price. Both references are in the same field of syngas production and share the goal of creating high-purity gas streams, making their combination straightforward.
    • Expectation of Success: Success would be expected because the combination involves substituting known, compatible process units (e.g., Price's reformer configuration) into an analogous process (Terrien's) to achieve the predictable result of producing ammonia-ready syngas.

Ground 3: Obviousness of Claims 1-10, 17, and 19 over Licht in view of Price

  • Prior Art Relied Upon: Licht (Patent 8,137,422) and Price (’219 application).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground presented an alternative invalidity theory starting with Licht. Petitioner argued Licht discloses a process for converting natural gas into syngas using a pre-reformer and reformers, treating the syngas via a shift reaction and CO2 removal, and splitting the product stream for use as fuel, with both streams having the same composition. Price was then combined to supply the specific "ATR downstream from a prereformer without a primary reformer" configuration, which a POSITA would recognize as a more efficient substitute for Licht’s secondary reformer. Price also explicitly provides the motivation to use the process for ammonia synthesis and teaches additional purification and methanation steps (claims 2 and 5).
    • Motivation to Combine: A POSITA would combine the teachings to improve the efficiency of Licht’s hydrogen production process by incorporating the well-known ATR configuration from Price. The goal would be to apply Licht’s carbon-reducing process to the specific, commercially important end-product of ammonia, as detailed in Price.
    • Expectation of Success: A POSITA would have a high expectation of success, as combining these known syngas process steps from analogous references would yield predictable improvements in efficiency and product application.

  • Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations adding Ji (Patent 8,309,617) to teach recycling of purge gas for claim 11 and Rytter (Patent 6,809,121) to teach specific, well-known operating ranges for fuel fraction percentages and oxygen concentrations for claims 3-4 and 8-9.

4. Relief Requested

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