PTAB

IPR2025-01173

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 from hydrocarbons (e.g., methane) while separating carbon dioxide (CO2) to reduce emissions. The core of the claimed invention is a dual reforming arrangement using an endothermic reforming step thermally coupled with an autothermal reforming (ATR) step, followed by a series of gas separation steps.

3. Grounds for Unpatentability

Ground 1: Anticipation over Reinertsen - Claims 1, 11, and 12 are anticipated by Reinertsen under 35 U.S.C. §102.

  • Prior Art Relied Upon: Reinertsen (Application # 2023/0119784).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Reinertsen discloses every element of independent claims 1 and 12 and dependent claim 11. Specifically, Reinertsen teaches a process for hydrogen production with CO2 separation that uses a dual reformer in a series configuration. This configuration includes a gas-heated reformer (GHR) for an endothermic step and an ATR, where heat from the ATR is explicitly recycled to provide heat for the endothermic GHR step. Reinertsen further discloses all subsequent claimed steps, including a water-gas shift reaction, hydrogen separation via pressure swing adsorption (PSA), and cryogenic CO2 separation from the residual gas stream, including the necessary compression and cooling steps.

Ground 2: Obviousness over Reinertsen and Darde - Claims 1-6, 11, and 12 are obvious over Reinertsen in view of Darde under 35 U.S.C. §103.

  • Prior Art Relied Upon: Reinertsen (Application # 2023/0119784) and Darde (WO 2014/091098).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Reinertsen teaches the key dual reformer configuration (thermally coupled endothermic reformer and ATR) that the patent examiner considered novel during prosecution. Darde, acknowledged as prior art in the ’805 patent, discloses a conventional hydrogen production process that explicitly teaches using PSA for hydrogen separation upstream of a cryogenic CO2 purification unit. Petitioner argued that while Reinertsen discloses both PSA and membrane separation for hydrogen, combining Reinertsen's dual-reformer process with Darde's explicit teaching of a PSA-cryogenic separation sequence renders the claimed process obvious. Darde supplements Reinertsen by explicitly describing the composition of the residual gas streams and the process for separating a second hydrogen-rich stream.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would combine Reinertsen and Darde to solve the common, recognized problem of producing hydrogen with reduced CO2 emissions. Darde teaches that using PSA upstream of cryogenic separation yields high-purity hydrogen and an off-gas with a high CO2 concentration, ideal for efficient cryogenic capture. A POSA would have been motivated to implement this known, predictable separation sequence from Darde into the advanced dual-reforming process of Reinertsen to achieve well-documented benefits of energy efficiency and high CO2 capture rates.
    • Expectation of Success: A POSA would have a high expectation of success, as the combination merely applies a known separation technique (PSA upstream of cryogenic CO2 capture from Darde) to a similar process stream (syngas from Reinertsen's dual reformer). Both references use well-known, compatible unit operations to achieve the same goal.

Ground 3: Obviousness over Rytter and Darde - Claims 1, 6, 11, and 12 are obvious over Rytter in view of Darde under §103.

  • Prior Art Relied Upon: Rytter (WO 2019/162236) and Darde (WO 2014/091098).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground presented an alternative to Ground 2, with Rytter serving as the primary reference. Petitioner argued Rytter, like Reinertsen, discloses the core dual-reforming process with a GHR and an ATR in a series configuration where heat from the ATR is used to heat the GHR. Rytter also discloses the downstream water-gas shift, hydrogen separation, and CO2 separation steps. While Rytter’s main embodiment shows CO2 separation upstream of H2 separation, it explicitly discloses that the sequence is selectable and that H2 separation can occur first.
    • Motivation to Combine: The motivation is similar to Ground 2. A POSA, aware from Rytter that the separation sequence is a design choice, would have looked to references like Darde for guidance on optimizing the process. Darde provides a clear teaching and rationale for placing PSA upstream of cryogenic CO2 separation to improve capture efficiency. A POSA would have been motivated to substitute this known, advantageous sequence into Rytter’s process to achieve the recognized goal of efficient, low-emission hydrogen production.
    • Expectation of Success: A POSA would expect success because it involves the routine optimization of a finite number of known design choices (i.e., the order of H2/CO2 separation) to achieve predictable results.

  • Additional Grounds: Petitioner asserted an additional obviousness challenge (Ground 4) against claims 2-5 based on Reinertsen, Darde, and Terrien (Application # 2012/0291484), arguing Terrien provides explicit teachings on recycling hydrogen-rich streams to further increase process efficiency.

4. Key Technical Contentions

  • Unsupported Assertions of Unexpected Results: Petitioner contended that the ’805 patent’s claims of “surprisingly significant” reductions in CO2 emissions are not supported by credible evidence. The petition argued that the material balance simulations provided in the patent’s specification contain clear errors and discrepancies, including a failure to achieve an elemental carbon balance. Petitioner asserted these flawed simulations cannot serve as evidence of unexpected results to overcome a prima facie case of obviousness.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-6, 11, and 12 of Patent 11,673,805 as unpatentable.