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IPR2025-01454

Topsoe Inc v. Casale SA

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Process for Synthesis of Ammonia
  • Brief Description: The ’168 patent discloses a process for converting natural gas into synthesis gas (syngas) for the subsequent synthesis of ammonia. The process involves a specific conversion section configuration and splitting the resulting CO2-depleted syngas into a fuel fraction and a process gas fraction.

3. Grounds for Unpatentability

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

  • Prior Art Relied Upon: 2007 IFA (a slide presentation from the International Fertilizer Association Technical Committee Meeting, Mar. 2007).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that 2007 IFA, a publicly accessible presentation, discloses every limitation of independent claim 1. It allegedly teaches a process for ammonia synthesis that converts desulphurized natural gas and steam with oxygen into syngas using a conversion section that includes an autothermal reformer (ATR) downstream from a pre-reformer, without an intermediate primary reformer. The reference further discloses treating the syngas via a shift reaction and CO2 removal, and then splitting the CO2-depleted syngas stream. One stream ("H2 Fuel") is used as fuel for a gas turbine and steam generator, while the second stream ("ammonia syngas") is intended for ammonia synthesis. Petitioner asserted that a POSA would understand from the process diagram that these two streams, branching from a single point without intervening treatment, necessarily have the same composition.
    • Prior Art Mapping (Dependent Claims): Petitioner contended 2007 IFA also explicitly discloses the limitations of dependent claims 5 (methanation and nitrogen addition), 6 (separating the fuel fraction upstream of methanation/nitrogen addition), and 10 (feeding the fuel fraction to a steam production/superheating furnace).

Ground 2: Claims 1, 3-4, 8-10, and 18 are anticipated and/or obvious over Rytter under 35 U.S.C. §§ 102/103.

  • Prior Art Relied Upon: Rytter (Patent 6,809,121).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued Rytter discloses all elements of claim 1. Rytter teaches a process for syngas production (including for ammonia synthesis) using a conversion section with a pre-reformer followed by an ATR without a primary reformer. It also describes treating the syngas via a shift reaction and CO2 removal. Rytter further discloses splitting the H2-containing stream, with part supplied as fuel to a reforming plant or heat-generating station and the remaining part used for methanol or ammonia synthesis. Petitioner asserted that splitting "part of the H2-containing stream" inherently results in streams of the same composition.
    • Prior Art Mapping (Dependent Claims): Rytter allegedly discloses the specific fuel fraction percentages of claims 3-4 (disclosing a range up to 95% for fuel) and the use of "substantially pure O2" which meets the oxygen concentration levels of claims 8-9. It also teaches feeding the fuel fraction to furnaces for steam production (claim 10) and producing excess syngas that can be exported (claim 18).

Ground 3: Claims 1-2, 5-6, 10, and 19 are anticipated by Fjellhaug under 35 U.S.C. §102.

  • Prior Art Relied Upon: Fjellhaug (Patent 6,505,467).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued Fjellhaug anticipates claim 1 by disclosing a process for producing syngas for ammonia synthesis. The process uses a pre-reformer upstream of an air-driven ATR with no primary reformer therebetween. While not explicitly stating desulfurization, Petitioner contended it is inherent for ATR use. Fjellhaug also shows CO shift and CO2 removal, followed by splitting the syngas stream. A first stream is used as fuel, and second streams are intended for ammonia synthesis. Petitioner asserted that because the ammonia feed is "drawn from" the line that also provides the fuel stream, the streams have the same composition.
    • Prior Art Mapping (Dependent Claims): Fjellhaug allegedly discloses further purification via a membrane unit (claim 2), a methanation step (claim 5) upstream of which the fuel is separated (claim 6), use of the fuel in gas turbines to produce steam (claim 10), and a steam/carbon ratio not greater than 2 (claim 19).

  • Additional Grounds: Petitioner asserted numerous additional obviousness challenges based on combinations of the primary references with secondary art. These included: 2007 IFA in view of Rytter, Price, Ji, or Licht; Rytter in view of Price, Ji, or Licht; and Fjellhaug in view of Rytter, Ji, or Licht. These grounds relied on combining references to supply teachings for specific operating ranges (e.g., fuel fraction percentages, oxygen concentrations, steam/carbon ratios) or to add well-known process steps (e.g., purge gas recycling, trim fuel use, further purification).

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-11 and 17-19 of the ’168 patent as unpatentable.