DCT

4:25-cv-00154

Midwest Energy Emissions Corp v. Evergy Kansas Central Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 4:25-cv-00050, W.D. Mo., 01/23/2025
  • Venue Allegations: Venue is asserted based on Defendants' residence within the district and their operation of coal-fired power plants, which constitute regular and established places of business where the alleged acts of infringement occurred.
  • Core Dispute: Plaintiff alleges that Defendants’ operation of coal-fired power plants infringes six patents related to methods for removing mercury from flue gas emissions.
  • Technical Context: The technology addresses the need for coal-fired power plants to comply with federal environmental regulations by capturing mercury before it is released into the atmosphere.
  • Key Procedural History: The complaint references a prior lawsuit in the District of Delaware against other parties, which resulted in a March 1, 2024 jury verdict finding two of the patents-in-suit (U.S. Patent Nos. 10,343,114 and 10,596,517) were willfully infringed. Plaintiff also alleges it contacted Defendants to negotiate a license on multiple occasions between August 2016 and February 2022, providing notice of the patented technology.

Case Timeline

Date Event
2004-08-30 Earliest Patent Priority Date ('114, '517, '225, '430, '370, '218 Patents)
2016-08-02 Plaintiff alleges first contact with Defendants for licensing negotiations
2018-11-01 Plaintiff alleges second contact with Defendants for licensing negotiations
2019-07-09 U.S. Patent No. 10,343,114 Issued
2019-07-XX Plaintiff filed related complaint in the District of Delaware
2019-08-07 Plaintiff alleges third contact with Defendants for licensing negotiations
2020-03-17 U.S. Patent No. 10,589,225 Issued
2020-03-24 U.S. Patent No. 10,596,517 Issued
2020-06-02 U.S. Patent No. 10,668,430 Issued
2021-02-23 U.S. Patent No. 10,926,218 Issued
2021-03-02 U.S. Patent No. 10,933,370 Issued
2022-02-08 Plaintiff alleges fourth contact with Defendants for licensing negotiations
2024-03-01 Jury verdict in Delaware case finds '114 and '517 Patents willfully infringed
2025-01-23 Complaint Filing Date

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

U.S. Patent No. 10,343,114 - “Sorbents for the Oxidation and Removal of Mercury”

  • Patent Identification: U.S. Patent No. 10,343,114, “Sorbents for the Oxidation and Removal of Mercury,” issued July 9, 2019 (Compl. ¶165).

The Invention Explained

  • Problem Addressed: The patent family addresses the challenge that conventional methods for removing mercury from coal-fired power plant flue gas are inefficient and costly (U.S. 10,933,370 B2, col. 2:5-38). Existing sorbents like activated carbon are initially unreactive, must be used in large quantities, are difficult to separate from collected ash, and create solid waste disposal problems that prevent the ash from being reused (U.S. 10,933,370 B2, col. 2:26-38).
  • The Patented Solution: The invention is a method for enhancing mercury removal by first introducing a halogen or halide additive (e.g., a bromine compound) into the coal or combustion chamber, which oxidizes the elemental mercury in the flue gas (U.S. 10,933,370 B2, col. 7:21-30). Subsequently, a sorbent material, such as activated carbon, is injected downstream to capture the now-oxidized mercury, which is then collected by particulate control devices like a baghouse or electrostatic precipitator (’114 Patent, Claim 25; U.S. 10,933,370 B2, col. 1:12-16).
  • Technical Importance: This two-part approach of using a halogen promoter followed by a sorbent was designed to create a more cost-effective and efficient mercury removal process, thereby enabling power plants to better comply with environmental regulations (Compl. ¶¶ 45, 52; U.S. 10,933,370 B2, col. 2:38-44).

Key Claims at a Glance

  • The complaint asserts infringement of at least Claim 25 (Compl. ¶168).
  • Independent Claim 25 is a method claim comprising the following essential elements:
    • combusting coal in a combustion chamber to provide mercury-containing gas, where the coal or the chamber comprises an added bromine-based compound (Br2, HBr, or a bromide compound);
    • injecting a sorbent material comprising activated carbon into the gas downstream of the combustion chamber;
    • contacting mercury in the gas with the sorbent to form a mercury/sorbent composition; and
    • separating the mercury/sorbent composition from the gas to form a cleaned gas.
  • The complaint reserves the right to assert claims 1-30 (Compl. ¶168).

U.S. Patent No. 10,596,517 - “Sorbents for the Oxidation and Removal of Mercury”

  • Patent Identification: U.S. Patent No. 10,596,517, “Sorbents for the Oxidation and Removal of Mercury,” issued March 24, 2020 (Compl. ¶186).

The Invention Explained

  • Problem Addressed: As with the related ’114 Patent, this patent addresses the technical and economic shortcomings of prior art mercury sorbents, which require large volumes and long reaction times to effectively capture mercury from flue gas streams (U.S. 10,596,517 B2, col. 2:5-38).
  • The Patented Solution: The patent claims a method for reducing mercury in flue gas by combusting coal that contains a bromine-based additive (Br2, HBr, or a bromide compound) to form a mercury-containing gas (U.S. 10,596,517 B2, col. 1:50-57). The mercury is then collected from this gas using a sorbent comprising activated carbon, which is added to the gas stream downstream of the combustion chamber (’517 Patent, Claim 1).
  • Technical Importance: The claimed method provides a more reactive and efficient process for capturing mercury, allowing power plants to achieve regulatory compliance more economically than with conventional methods that rely solely on un-promoted sorbents (U.S. 10,596,517 B2, col. 2:38-44).

Key Claims at a Glance

  • The complaint asserts infringement of at least Claim 1 (Compl. ¶189).
  • Independent Claim 1 is a method claim comprising the following essential elements:
    • combusting coal in a combustion chamber, the coal comprising an additive (Br2, HBr, a bromide compound, or a combination thereof), to form the mercury-containing gas; and
    • collecting mercury in the gas with a sorbent comprising activated carbon, which is added to the gas.
  • The complaint reserves the right to assert claims 1-30 (Compl. ¶189).

U.S. Patent No. 10,589,225 - “Sorbents for the Oxidation and Removal of Mercury”

  • Patent Identification: U.S. Patent No. 10,589,225, “Sorbents for the Oxidation and Removal of Mercury,” issued March 17, 2020 (Compl. ¶203).
  • Technology Synopsis: The patent claims a method for treating mercury-containing gas by combusting a mixture that includes coal, pyrolysis char, and a bromide-based additive (HBr or a bromide compound). A particulate sorbent of activated carbon is then added to the resulting gas to capture the mercury (Compl. ¶¶ 210, 212).
  • Asserted Claims: At least Claim 1 (Compl. ¶¶ 206, 208).
  • Accused Features: The operation of Defendants' coal-fired power plants, which allegedly combust coal with bromide additives and inject activated carbon sorbent downstream to comply with mercury regulations (Compl. ¶¶ 209, 211, 213).

U.S. Patent No. 10,668,430 - “Sorbents for the Oxidation and Removal of Mercury”

  • Patent Identification: U.S. Patent No. 10,668,430, “Sorbents for the Oxidation and Removal of Mercury,” issued June 2, 2020 (Compl. ¶¶ 38, 220).
  • Technology Synopsis: This patent claims a method for separating mercury from gas that specifies the timing of the additive introduction. A bromide-based additive is added to the coal before the coal enters the combustion chamber, or the combustion chamber itself comprises the additive. Activated carbon sorbent is then injected downstream to capture the mercury (Compl. ¶227).
  • Asserted Claims: At least Claim 1 (Compl. ¶¶ 223, 225).
  • Accused Features: The operation of Defendants' coal-fired power plants, which allegedly add bromide-based additives to coal prior to or during combustion and subsequently inject activated carbon sorbent to remove mercury (Compl. ¶¶ 226, 228, 230).

U.S. Patent No. 10,933,370 - “Sorbents for the Oxidation and Removal of Mercury”

  • Patent Identification: U.S. Patent No. 10,933,370, “Sorbents for the Oxidation and Removal of Mercury,” issued March 2, 2021 (Compl. ¶241).
  • Technology Synopsis: This patent claims a mercury separation method that introduces a specific quantitative limitation. It requires that the weight ratio of the halide/halogen additive to the amount of activated carbon sorbent is "from about 1:100 to about 30:100" (Compl. ¶250).
  • Asserted Claims: At least Claim 1 (Compl. ¶¶ 244, 246).
  • Accused Features: The operation of Defendants' coal-fired power plants, which allegedly use a process of adding halide/halogen additives and activated carbon sorbent that falls within the claimed weight ratio (Compl. ¶251).

U.S. Patent No. 10,926,218 - “Sorbents for the Oxidation and Removal of Mercury”

  • Patent Identification: U.S. Patent No. 10,926,218, “Sorbents for the Oxidation and Removal of Mercury,” issued February 23, 2021 (Compl. ¶262).
  • Technology Synopsis: This patent claims a mercury separation method similar to the ’370 Patent but specifies the use of an iodine-based additive (HI, an iodide salt, or a combination thereof). It also requires the same weight ratio of additive to sorbent of "from about 1:100 to about 30:100" (Compl. ¶¶ 269, 271).
  • Asserted Claims: At least Claim 1 (Compl. ¶¶ 265, 267).
  • Accused Features: The operation of Defendants' coal-fired power plants, which allegedly use an iodine-based additive and activated carbon sorbent in a process that falls within the claimed weight ratio (Compl. ¶¶ 270, 272).

III. The Accused Instrumentality

  • Product Identification: The accused instrumentalities are the mercury removal methods performed at the Iatan, Hawthorn, La Cygne, Jeffrey Energy Center (JEC), and Lawrence coal-fired power plants (the "Accused Coal Plants") (Compl. ¶112).
  • Functionality and Market Context:
    • The complaint alleges that to comply with the EPA's Mercury and Air Toxics Standards (MATS), Defendants' power plants perform a multi-step process for mercury removal (Compl. ¶111). This allegedly involves combusting coal with an added bromine, bromide, iodine, or other halogen/halide compound in a combustion chamber (Compl. ¶112). Downstream from the chamber, a sorbent material comprising activated carbon is injected into the flue gas (Compl. ¶112). The mercury, now bound to the activated carbon, is collected in a particulate collection device such as a baghouse or an electrostatic precipitator (ESP) (Compl. ¶112).
    • The complaint asserts that these operational steps are necessary for the Accused Coal Plants to meet their regulatory obligations under MATS, particularly when burning low-sulfur Powder River Basin coal, which contains elemental mercury (Compl. ¶¶ 110-111).

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

'114 Patent Infringement Allegations

Claim Element (from Independent Claim 25) Alleged Infringing Functionality Complaint Citation Patent Citation
A method of separating mercury from a mercury-containing gas. Defendants perform the claimed method at the Accused Coal Plants to comply with mercury emissions regulations. ¶171 col. 2:45-50
combusting coal in a combustion chamber to provide the mercury-containing gas, wherein the coal comprises added Br2, HBr, a bromide compound, or a combination thereof, added to the coal upstream of the combustion chamber, or the combustion chamber comprises added Br2, HBr, a bromide compound, or a combination thereof... The Accused Coal Plants burn coal with an added bromine-based compound, or add such a compound directly to the combustion chamber, to generate flue gas containing mercury. ¶173 col. 2:50-57
injecting a sorbent material comprising activated carbon into the mercury containing gas downstream of the combustion chamber. The Accused Coal Plants inject an activated carbon sorbent into the flue gas after it has exited the combustion chamber. ¶175 col. 2:8-16
contacting mercury in the mercury-containing gas with the sorbent, to form a mercury/sorbent composition. Mercury present in the flue gas exiting the combustion chamber makes contact with the injected sorbent within the same gas stream. ¶177 col. 2:16-20
separating the mercury/sorbent composition from the mercury-containing gas, to form a cleaned gas. The Accused Coal Plants use equipment such as baghouses or electrostatic precipitators to collect the sorbent, with the captured mercury, from the flue gas. ¶179 col. 2:13-16
  • Identified Points of Contention:
    • Scope Questions: A potential dispute may arise over the definition of "a bromide compound." Defendants may argue that the specific chemical additives they use do not fall within the scope of this term as it is defined by the patent's specification and prosecution history.
    • Technical Questions: The factual basis for infringement will depend on evidence that Defendants' processes meet every step of the claimed method. A key question will be whether Defendants add a bromine-based compound for the purpose of mercury oxidation, as claimed, or for other unrelated operational reasons.

'517 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A method for reducing mercury in a mercury-containing gas. Defendants perform the claimed method at the Accused Coal Plants to comply with mercury emissions regulations. ¶192 col. 2:45-50
combusting coal in a combustion chamber, the coal comprising an additive comprising Br2, HBr, a bromide compound, or a combination thereof, to form the mercury-containing gas. The Accused Coal Plants combust coal treated with a bromine-based additive, which creates a mercury-containing flue gas. ¶194 col. 2:50-57
collecting mercury in the mercury-containing gas with a sorbent added to the mercury-containing gas, the sorbent comprising activated carbon. An activated carbon sorbent is added to the flue gas after combustion, and equipment such as baghouses or ESPs collects the sorbent and the mercury bound to it. ¶196 col. 2:8-16
  • Identified Points of Contention:
    • Scope Questions: The term "collecting mercury...with a sorbent" may be a point of contention. The claim language suggests a single functional step, whereas the physical process involves both contact (adsorption) and subsequent physical separation (collection). The parties may dispute whether the defendants' use of separate ESPs or baghouses to capture the sorbent constitutes "collecting...with a sorbent" as claimed.
    • Technical Questions: As with the ’114 Patent, a central factual question will be demonstrating that the additives used by Defendants are, in fact, the bromide compounds covered by the claim and that they are used in the manner described.

V. Key Claim Terms for Construction

  • The Term: "a bromide compound" (’114 Patent, Claim 25; ’517 Patent, Claim 1)
  • Context and Importance: This term is central to the infringement analysis for five of the six asserted patents. The scope of "bromide compound" will determine which chemical additives fall within the claims. Defendants' liability may depend on whether the specific additives used at their plants are construed to be "bromide compounds."
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The claim language itself is broad, not limiting the term to any specific type of bromide compound (e.g., U.S. 10,596,517 B2, col. 36:13-16). The specification of the related ’370 patent describes promoters including "Group V" and "Group VI" halides, suggesting a broad chemical scope was contemplated (U.S. 10,933,370 B2, col. 3:6-8).
    • Evidence for a Narrower Interpretation: Defendants may argue that the term should be limited to the specific examples disclosed in the patent's detailed description, such as HBr or PBr3 (e.g., U.S. 10,933,370 B2, col. 17:1-12), or that prosecution history estoppel narrows its scope.
  • The Term: "sorbent comprising activated carbon" (’517 Patent, Claim 1)
  • Context and Importance: Practitioners may focus on this term because the accused process may involve injecting a sorbent that contains materials in addition to activated carbon. Whether such a mixture meets the "sorbent comprising activated carbon" limitation is a potential point of dispute.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The term "comprising" is a transitional phrase in patent law that is generally interpreted as being open-ended, meaning "including but not limited to." This suggests the sorbent can contain activated carbon as one component among others. The specification of the related ’370 patent describes the use of a "base activated carbon" to which optional secondary components and alkali may be added, supporting the idea of a multi-component sorbent (U.S. 10,933,370 B2, col. 3:4-24).
    • Evidence for a Narrower Interpretation: A defendant may argue that in the context of the invention, the "sorbent" refers to the active material responsible for mercury capture, which the patent identifies as activated carbon. Any other materials in an injected mixture could be characterized as inert carriers or separate additives rather than part of the "sorbent" itself.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that the parent company, Evergy, Inc., induced infringement by its subsidiaries by exercising control over their operations and participating in supply contracts for the bromine additives and activated carbon (Compl. ¶¶ 181, 198). It also alleges inducement by non-operating co-owners of the plants, who allegedly direct and pay the plant operators to perform the infringing methods to ensure regulatory compliance (Compl. ¶¶ 182, 199).
  • Willful Infringement: The willfulness allegations are based on alleged pre-suit knowledge. The complaint asserts that Defendants were repeatedly notified of the patents and their infringement starting in August 2016 (Compl. ¶¶ 153-157, 160). The complaint further supports its willfulness claim by citing the March 2024 jury verdict in a separate Delaware case, which found that infringement of the ’114 and ’517 patents by other parties using similar technology was willful (Compl. ¶69).

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

  • A core issue will be one of evidentiary proof for ratio claims: For the ’370 and ’218 patents, which require a specific weight ratio of additive-to-sorbent, a key question will be whether Plaintiff can produce evidence from Defendants' operational data demonstrating that the accused power plants consistently operate within the claimed numerical range of "about 1:100 to about 30:100."
  • A second key question will be one of corporate liability and intent: Can Plaintiff establish that the parent entity (Evergy, Inc.) and non-operating co-owners exercised sufficient specific control and possessed the requisite knowledge and intent to be held liable for inducing the infringement allegedly carried out by the plant operators?
  • Finally, a central question for damages will be the scope of willfulness: Given the allegations of extensive pre-suit notice and a prior jury verdict finding willfulness for the ’114 and ’517 patents, a critical issue for the court will be whether Defendants’ continued use of the accused methods after receiving such notice constitutes the type of egregious conduct required to support a finding of willful infringement and enhanced damages across all six asserted patents.