DCT

1:26-cv-01061

Ingenco Holdings LLC v. Opal Fuels Inc

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Key Events
Complaint
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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 1:26-cv-01061, D. Del., 08/20/2026
  • Venue Allegations: Venue is alleged to be proper in the District of Delaware because each Defendant is a Delaware corporation or limited liability company and therefore resides in the district for patent venue purposes.
  • Core Dispute: Plaintiff alleges that Defendants' renewable natural gas facilities infringe a patent covering a multi-step method for processing landfill gas into pipeline-quality natural gas.
  • Technical Context: The lawsuit concerns technology for purifying "stranded" methane-containing gas, such as landfill gas, by removing contaminants like carbon dioxide, nitrogen, and oxygen to create a commercially viable energy product.
  • Key Procedural History: The complaint references a related action involving the same patent against a different portfolio of renewable natural gas facilities. It also details an extensive pre-suit history, including Label License Agreements that allegedly put certain Defendants on notice of the patent, and a subsequent dispute over Plaintiff's contractual right to inspect the accused facilities, which Plaintiff alleges was refused by Defendants.

Case Timeline

Date Event
2005-10-28 '779 Patent Priority Date
2006-10-27 '779 Patent Application Filing Date
2010-06-08 '779 Patent Issue Date
2012-02-15 Air Liquide License Agreement executed between IPGCo and Air Liquide
2015-05-26 '779 Patent assigned from IPGCo to BEW
2020-12-16 Air Permit Minor Amendment application filed for the Pine Bend Project
2022-01-10 New Source Review Permit Application filed for the Prince William Project
2022-08-29 Request for Permit to Install filed for the Emerald Project
2022-10-01 Pine Bend Project commences commercial operation (approx.)
2022-11-02 Permit-to-Construct Application filed for the Sapphire Project
2023-03-14 '779 Patent assigned from BEW to Plaintiff Ingenco Holdings
2023-08-11 Air Construction Permit Application filed for the Polk County Project
2023-10-01 Emerald Project commences commercial operation (approx. Q3/Q4)
2023-10-04 NCDEQ Title V Air Permit issued for the Sapphire Project
2024-01-01 Prince William Project commences commercial operation (approx. Q1)
2024-03-01 Label License Agreement dated for the Polk County Project
2025-08-14 Commencement Date for Sapphire Project Label License Agreement
2026-04-15 Related case, Ingenco Holdings, LLC v. WM Renewable Energy, L.L.C., filed
2026-05-08 Plaintiff sends notice letters to Defendants regarding infringement
2026-05-11 Notice letters delivered to Defendants
2026-05-26 Plaintiff sends follow-up letter to Defendants
2026-05-27 License Agreement rights assigned from BEW to Plaintiff Ingenco Holdings
2026-08-20 Complaint filed
2028-09-24 '779 Patent Expiration Date (with extension)

II. Technology and Patent(s)-in-Suit Analysis

  • Patent Identification: U.S. Patent No. 7,731,779, Method for Processing Landfill and Other Stranded Gas Containing Commercial Quantities of Methane and Contaminated by Carbon Dioxide, Nitrogen and Oxygen into a Pipeline or Vehicle Quality Natural Gas Product, issued June 8, 2010.

The Invention Explained

  • Problem Addressed: The patent addresses the problem that "stranded" natural gas, particularly landfill gas (LFG), is often contaminated with carbon dioxide, nitrogen, and oxygen, making it uneconomical to process into pipeline-quality gas using traditional, capital-intensive cryogenic separation techniques '779 Patent, background, col. 1:19-30 '779 Patent, background, col. 2:12-23 Air infiltration into LFG collection systems introduces nitrogen and oxygen, which have historically been difficult to remove successfully '779 Patent, background, col. 2:45-54
  • The Patented Solution: The invention claims a modular, multi-step process that uses a specific sequence of non-cryogenic technologies to purify the gas '779 Patent, summary, col. 2:49-53 The process involves steps for removing hydrogen sulfide, compressing and cooling the gas, and then using a combination of pressure swing adsorption (PSA) units and process membranes to sequentially remove water, organic compounds, carbon dioxide, oxygen, and nitrogen '779 Patent, fig. 2 '779 Patent, detailed desc., col. 3:36-61 A key feature is the use of permeate (reject gas) from the membrane stage to regenerate other units or be recycled to improve overall methane recovery '779 Patent, claims 1, 4
  • Technical Importance: The patented method provides a way to make previously unusable or underutilized gas sources, like landfill gas, economically viable for injection into commercial natural gas pipelines or for use as vehicle fuel '779 Patent, abstract

Key Claims at a Glance

  • The complaint asserts at least independent claims 1 and 4 '779 Patent, claims 1, 4 Compl. ¶33
  • Independent Claim 1 includes the following essential elements:
    • removing hydrogen sulfide from the gas;
    • compressing the gas;
    • cooling the gas;
    • removing water, non methane organic compounds, and volatile organic compounds using one or more pressure swing adsorption units;
    • removing carbon dioxide and oxygen using process membranes;
    • removing nitrogen and oxygen using one or more pressure swing adsorption units;
    • wherein the step of removing carbon dioxide and oxygen using process membranes produces permeate which is then used in the step of recycling the gas to improve methane recovery.
  • Independent Claim 4 is similar but specifies that the permeate from the membrane step is used to regenerate the upstream PSA units used for water and organic compound removal.
  • The complaint reserves the right to assert dependent claims as evidence may show Compl. ¶33

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are five landfill renewable natural gas (RNG) facilities: the Polk County Project, the Sapphire Project, the Pine Bend Project, the Emerald Project, and the Prince William Project (the "Infringing Projects") Compl. ¶1

Functionality and Market Context

  • Each accused facility is alleged to process landfill gas into pipeline-quality RNG for injection into natural gas pipelines Compl. ¶30 The complaint asserts that each facility employs the same core "membrane- and pressure-swing-adsorption-based gas-treatment architecture" Compl. ¶1 Compl. ¶30
  • The complaint alleges this common design origin is confirmed by public records and the resume of an engineer from SCS Energy, who is identified as the designer for each of the five projects Compl. ¶¶1 Compl. ¶25 Compl. ¶30 The resume, attached as Exhibit H to the complaint, is described as identifying the projects as utilizing "carbon-dioxide membrane separation and nitrogen pressure-swing-adsorption separation technology" Compl. ¶11 Compl. ¶30
  • The complaint alleges that through the operation of these facilities, Defendants generate substantial revenues from natural gas sales and the sale of D-3 Renewable Identification Numbers ("RINs") under the EPA's Renewable Fuel Standard Compl. ¶41

IV. Analysis of Infringement Allegations

The complaint alleges that each of the five Infringing Projects practices the patented method, detailing the specific configuration of each project based on public permitting records and design drawings Compl. ¶¶31-38 The allegations for the Sapphire Project are presented below as a representative example.

'779 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
removing hydrogen sulfide from the gas The project performs this step via its "sulfur-removal stage." ¶33 col. 3:36-41
compressing the gas; cooling the gas This is performed by the project's "gas compressors and coolers." ¶33 col. 3:41-43
removing water, non methane organic compounds, and volatile organic compounds using one or more pressure swing adsorption units This is allegedly performed by the first of two PSA systems identified in the project's Title V Air Permit, described in a regulatory filing as a PSA process that removes NMOC and sulfur-bearing compounds. ¶32; ¶33 col. 3:44-53
removing carbon dioxide and oxygen using process membranes This is performed by "Air Liquide membrane separation skids" identified in a General Arrangement drawing, where carbon dioxide is separated from methane. ¶33; ¶35 col. 3:56-61
removing nitrogen and oxygen using one or more pressure swing adsorption units This is performed by the second of the two PSA systems identified in the Title V Air Permit. ¶33; ¶35 col. 4:5-11
wherein the step of removing carbon dioxide and oxygen using process membranes produces permeate which is then used in the step of recycling the gas to improve methane recovery This is performed by the project's "permeate-handling configuration," with a General Arrangement drawing allegedly showing a "dedicated recycle-compressor train and a vacuum-compressor train" corroborating the recycle. ¶33; ¶35 col. 4:60-64

Identified Points of Contention

  • Technical Questions: A central question may be whether the equipment at each accused facility, particularly the units alleged to be "pressure swing adsorption units," actually operates in the manner required by the claims. The complaint notes that for some projects, the internal configuration of certain equipment (e.g., the Air Liquide-supplied skids) is not publicly disclosed, and infringement of the upstream PSA step is alleged "upon information and belief" Compl. ¶31 Compl. ¶36 The General Arrangement drawing for the Sapphire Project (G-100) is cited as evidence identifying an "upstream adsorption train" Compl. ¶35, which may become a key piece of evidence.
  • Scope Questions: The dispute may turn on the precise definition of "pressure swing adsorption" and whether the Defendants' systems, which the complaint sometimes describes as "regenerative" or "non-regenerating" Compl. ¶14 Compl. ¶16, fall within the claim scope. The complaint alleges that even if not literally present, the steps are practiced under the doctrine of equivalents Compl. ¶65

V. Key Claim Terms for Construction

  • The Term: "pressure swing adsorption units"
  • Context and Importance: This term appears in two separate limitations of the independent claims, referring to an upstream unit for removing water/VOCs and a downstream unit for removing nitrogen/oxygen '779 Patent, claims 1, 4 The complaint's entire infringement theory is predicated on the accused facilities employing a "membrane- and pressure-swing-adsorption-based" architecture Compl. ¶1 Practitioners may focus on this term because the factual question of whether Defendants' systems meet this definition will be critical to proving infringement. The complaint's own allegations suggest some ambiguity, referring to a "PSA process followed by non-regenerating activated-carbon vessels" at one project Compl. ¶32, which raises the question of whether "non-regenerating" vessels can be considered part of a "pressure swing adsorption" system.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification describes the function of the PSA units broadly as being for the "removal of water and nearly all non methane organic compounds (NMOC's) and volatile organic compounds (VOC's)" and for the separation of methane and nitrogen '779 Patent, col. 3:44-49 '779 Patent, col. 4:5-8 It refers to the technology by a trade name ("Molecular Gate™") as one example, but does not appear to limit the term to that specific embodiment '779 Patent, col. 4:8-9 This may support an interpretation based on the function performed rather than a specific operational mechanism.
    • Evidence for a Narrower Interpretation: The term "pressure swing adsorption" has a specific technical meaning involving cyclical adsorption at high pressure and regeneration (desorption) at low pressure. The specification notes that the PSA units for nitrogen rejection are "regenerated by pulling a vacuum on the adsorbent beds" '779 Patent, col. 4:27-28 A defendant may argue this description of regeneration is an essential feature of the claimed "pressure swing adsorption units," potentially excluding systems that operate differently or are described as "non-regenerating."

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that parent company OPAL Fuels induced infringement by its operating subsidiaries Compl. ¶66 The basis for this allegation includes OPAL Fuels' alleged direction and control over the design, construction, and operation of the infringing facilities; its knowledge of the '779 patent via Label License Agreements and notice letters; and its specific intent to cause infringement by deploying a common gas-treatment architecture across its portfolio Compl. ¶¶66-67
  • Willful Infringement: Willfulness is alleged based on both pre-suit and post-suit knowledge Compl. ¶69 The complaint alleges that two subsidiaries had actual notice from the moment they executed Label License Agreements that explicitly identified the '779 patent by number Compl. ¶43 It further alleges all Defendants had actual knowledge of the patent and infringement contentions no later than their receipt of formal notice letters on May 11, 2026 Compl. ¶43 Compl. ¶46 Continued operation after this notice is alleged to be willful and deliberate Compl. ¶61

VII. Analyst's Conclusion: Key Questions for the Case

  1. A core issue will be one of evidentiary proof: Can the Plaintiff, through discovery and the inspections it claims it was denied, establish that the internal, non-public workings of the Defendants' gas processing equipment-particularly the upstream adsorption units-perform the specific functions of "pressure swing adsorption" as required by the patent's claims?
  2. The case will likely involve a significant question of claim construction: Does the term "pressure swing adsorption units", as defined by the patent's specification and prosecution history, encompass the specific adsorption systems used by the Defendants, especially where the complaint's own evidence describes some components as "non-regenerating"?
  3. A central question for damages will be one of willfulness and notice: Did the "Label License Agreements," which identified the patent and required a separate "project-wide license," provide actual notice of infringement to the signatory Defendants, and did the subsequent notice letters provide such notice to all Defendants, making their continued operation post-notice an act of willful infringement?