PTAB

IPR2025-01174

Topsoe Inc v. L'Air Liquide Société Anonyme pour l'Etude Et L'ExploitATION des Procédés Georges Claude

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Process and Plant for Preparation of Hydrogen and Separation of Carbon Dioxide
  • Brief Description: The ’805 patent discloses a process for producing hydrogen and separating carbon dioxide (CO2) from hydrocarbon gases. The process integrates an endothermic reforming step with an autothermal reforming (ATR) step, where heat generated from the exothermic ATR step is used to drive the endothermic reforming reaction, aiming to reduce overall CO2 emissions.

3. Grounds for Unpatentability

Ground 1: Obviousness over Martin and Rafati - Claims 1, 6, 11, and 12 are obvious over Martin in view of Rafati.

  • Prior Art Relied Upon: Martin (a 2019 conference presentation titled "Progress Update on the Allam Cycle") and Rafati (Application # 2019/0135626).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Martin discloses the core process of the ’805 patent, including a dual reformer system (ATR and a gas-heated reformer (GHR)) arranged in parallel, followed by downstream CO conversion (syngas shift), hydrogen separation via pressure swing adsorption (PSA), and CO2 separation using a low-temperature cryogenic system. However, as a high-level conference paper, Martin may lack specific operational details. Rafati was presented as disclosing a nearly identical parallel dual-reforming process for hydrogen production, providing the specific details of reactor configurations, process streams, and compositions that complement Martin’s framework. The combination of Martin’s overall process flow and Rafati’s detailed implementation allegedly discloses all limitations of independent claim 1 and the plant of claim 12.
    • Motivation to Combine: Petitioner contended a person of ordinary skill in the art (POSA) would combine Martin and Rafati because both address the same problem of producing hydrogen efficiently while minimizing CO2 emissions using the same parallel dual-reforming technology. Rafati was asserted to provide the well-known technical details needed to implement the process outlined in Martin, making the combination a predictable application of known principles to achieve a known goal.
    • Expectation of Success: A POSA would have a high expectation of success because the processes are highly compatible, using similar reactants, process conditions, and the same sequence of downstream separation units (CO shift, PSA, cryogenic CO2 removal).

Ground 2: Obviousness over Martin, Rafati, and Gauthier - Claims 2-4 and 6 are obvious over Martin and Rafati in further view of Gauthier.

  • Prior Art Relied Upon: Martin, Rafati, and Gauthier (Application # US2009/0298957).
  • Core Argument for this Ground:
    • Prior Art Mapping: Building on the Martin/Rafati combination for claim 1, Petitioner argued Gauthier teaches the additional limitations found in dependent claims 2-4 and 6. Gauthier discloses treating a purge gas stream from a cryogenic CO2 separation unit with a membrane permeation module to generate a second, purified hydrogen-rich stream (addressing claims 2 and 3). Gauthier further teaches recycling this second hydrogen-rich stream back into the primary PSA unit to increase overall hydrogen yield (addressing claim 4). For claim 6, Gauthier teaches purifying the primary CO2-rich stream via distillation to remove methane, a thermal separation process that produces a higher-value, food-grade CO2 product.
    • Motivation to Combine: A POSA would be motivated to add Gauthier's teachings to the Martin/Rafati process to achieve the well-understood goals of increasing hydrogen yield and improving the purity and value of the captured CO2. These modifications were presented as known, value-adding steps in the field of syngas processing.

Ground 3: Obviousness over Martin, Rafati, and Terrien - Claims 2-5 are obvious over Martin and Rafati in further view of Terrien.

  • Prior Art Relied Upon: Martin, Rafati, and Terrien (Application # 2012/0291484).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground again used the Martin/Rafati combination as the base process and added Terrien to teach the limitations of claims 2-5. Terrien discloses separating hydrogen from a residual gas stream using a membrane (addressing claims 2 and 3). Critically, Terrien teaches recycling the resulting hydrogen-rich permeate stream for use as fuel in the reforming unit (e.g., an SMR or ATR) to improve the process's overall energy efficiency and CO2 capture (addressing claim 5). Terrien also discloses recycling a hydrogen-rich stream to a PSA unit, similar to Gauthier (addressing claim 4).
    • Motivation to Combine: A POSA would be motivated to integrate Terrien's fuel recycling strategy into the Martin/Rafati process to improve energy efficiency, a primary objective in industrial chemical processes. Using a hydrogen-rich byproduct stream as fuel to reduce the consumption of natural gas was argued to be a known and logical process optimization.

4. Key Technical Contentions

  • Rebuttal of Unexpected Results: Petitioner argued that the ’805 patent’s assertion of "surprisingly significant" CO2 emission reductions is unsupported. The petition contended that the material balance simulations provided in Tables 2 and 3 of the patent contain significant errors and discrepancies, including a lack of elemental carbon balance, which undermines their credibility and prevents a meaningful comparison against the prior art to establish any unexpected benefits.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-6, 11, and 12 of the ’805 patent as unpatentable under 35 U.S.C. §103.