In Re: Midwest Energy Emissions Corp. Patent Litigation

This multidistrict litigation (MDL), captioned In Re: Midwest Energy Emissions Corp. Patent Litigation, case number 4:24-md-03132, is ongoing in the U.S. District Court for the Southern District of Iowa. The plaintiff is Midwest Energy Emissions Corp. (ME2C), an environmental services and technology company that has rebranded to Birchtech Corp. but is proceeding under its former name in this litigation. ME2C develops and provides mercury capture systems and technologies, specifically its Sorbent Enhancement Additive (SEA) technology, to the power industry for coal-fired power plants. The defendants are a consortium of energy companies, including MidAmerican Energy Company, Interstate Power and Light Company, Union Electric Co. (d/b/a Ameren Missouri), Wisconsin Power and Light Company, Ameren Corp., PacifiCorp, Evergy, Inc., Evergy Metro, Inc., Evergy Missouri West, Inc., and Evergy Kansas Central, Inc., all of whom operate coal-fired power plants. The accused technology involves methods and systems used by these defendants for capturing mercury pollution from the flue gas streams of their coal-fired power plants, specifically through the use of halogen additives (such as bromine and iodine) and activated carbon.

The litigation asserts multiple patents, including US Patent 10589225, which relates to sorbent injection systems and processes for reducing mercury. Other asserted patents include US10343114, US10596517, US10668430, US10926218, and US10933370. All six patents are titled "Sorbents for the Oxidation and Removal of Mercury," share common inventors, and originate from a single patent application. US10926218 specifically pertains to iodine-based additives. The procedural posture of this case is an MDL, centralized by the Judicial Panel on Multidistrict Litigation on December 12, 2024, in the Southern District of Iowa before Judge Stephen H. Locher, with Magistrate Judge William P. Kelly also assigned. The Southern District of Iowa was chosen as the transferee forum due to its central geographic location and the presence of the largest number of defendants in a single action, facilitating consolidated pretrial proceedings, discovery, and consistent rulings on claim construction and patent validity.

This case is notable for several reasons within the emissions control technology industry, highlighting critical intellectual property risks for stakeholders. While ME2C is an operating company, its robust patent enforcement against numerous entities in the power sector demonstrates an aggressive assertion strategy. Many defendants have sought to stay the MDL proceedings pending inter partes review (IPR) petitions filed, or planned to be filed, with the Patent Trial and Appeal Board (PTAB) challenging the validity of the asserted patents. The court has, however, denied motions to stay without prejudice, electing to proceed until the PTAB decides on institution. Several IPRs have already been initiated, including IPR2025-00274, which involves defendants Berkshire Hathaway Energy Company, MidAmerican Energy Company, and PacifiCorp challenging the '114 patent, with MidAmerican having already settled and moved for termination from that IPR. ME2C also has a history of successfully litigating these patents, having secured a $57 million patent infringement verdict in March 2024 in the District of Delaware against other coal industry operators for their use of mercury capture technologies.

The "In Re: Midwest Energy Emissions Corp. Patent Litigation" (MDL No. 3132) is a multidistrict litigation consolidating several patent infringement cases concerning methods for capturing mercury emissions from coal-fired power plants. The MDL was centralized in the U.S. District Court for the Southern District of Iowa. Midwest Energy Emissions Corp. (ME2C), which changed its corporate name to Birchtech Corp. on October 17, 2024, is the plaintiff.

Here's a chronological summary of the key legal developments:

1. Filing & Initial Pleadings (2024)

• Formation of MDL: The Judicial Panel on Multidistrict Litigation (JPML) issued a Transfer Order on December 12, 2024, centralizing three actions from the District of Arizona, the Eastern District of Missouri, and the Southern District of Iowa into MDL No. 3132 in the Southern District of Iowa. The centralization was deemed warranted to eliminate duplicative discovery, prevent inconsistent pretrial rulings (especially regarding claim construction and validity), and conserve resources.
• Patents Asserted: The litigation involves multiple patents, including U.S. Patent No. 10,589,225, along with 10,343,114, 10,596,517, 10,668,430, and 10,933,370, which are asserted in all three initial actions. U.S. Patent No. 10,926,218 is also asserted against several defendants in the Iowa action. All six patents are titled "Sorbents for the Oxidation and Removal of Mercury."
• Defendants and Counterclaims: Defendants include various energy companies such as MidAmerican Energy Company, Interstate Power and Light Company, Union Electric Co. (d/b/a Ameren Missouri), Wisconsin Power and Light Company, Ameren Corp., PacifiCorp, Evergy, Inc., Evergy Metro, Inc., Evergy Missouri West, Inc., and Evergy Kansas Central, Inc. Many defendants filed answers to the complaints, including affirmative defenses and counterclaims against Midwest Energy Emissions Corp. For example, MidAmerican Energy Company filed an Answer and Counterclaim on December 17, 2024.

2. Pre-trial Motions of Substance (2025)

• Motions to Stay Pending IPR: On May 22, 2025, the Court denied without prejudice Defendants' Motions to Stay the litigation pending decisions by the Patent Trial and Appeal Board (PTAB) on whether to institute inter partes review (IPR) proceedings. The Court stated that a stay would not be imposed before the PTAB decided on institution.
• Motion to Compel Infringement Contentions: Also on May 22, 2025, the Court denied Defendants' Joint Motion to Compel Supplemental Infringement Contentions and Joint Motion to Extend the Deadline for Defendants' Invalidity Contentions. The Court found that ME2C's Initial Infringement Contentions, which identified 116 patent claims across six patents, provided sufficient notice to the defendants.

3. Claim Construction (Markman) Outcomes

• As of the current date (2026-05-22), there is no publicly available information indicating that a Markman hearing has been held or a claim construction order has been issued in MDL No. 3132. The docket indicates discussions regarding Markman hearings, but no outcome is reported.

4. Discovery Milestones with Strategic Significance

• Plaintiff's Initial Infringement Contentions were served by March 18, 2025, and filed publicly as Exhibit A to ECF 106-3 in the MDL. The sufficiency of these contentions was a point of contention, leading to the denied motion to compel.

5. Trial Events, Verdict, and Post-Trial Motions

• No trial has occurred in the MDL No. 3132, as it is still in the pretrial phase.
• Related Case Outcome (Delaware): It is important to note that prior to the formation of this MDL, Midwest Energy Emissions Corp. had already litigated infringement claims against other defendants in the District of Delaware (e.g., Midwest Energy Emissions Corp. v. Arthur J. Gallagher & Co., et al., No: 1:19-cv-01334). In that Delaware case, a federal jury awarded ME2C a $57 million patent infringement verdict on March 1, 2024, for infringement of U.S. Patent Nos. 10,343,114 and 10,596,517. Post-trial motions, such as for JMOL, were subsequently denied in that Delaware case on September 25, 2025. This prior litigation and its outcome were noted by the JPML when centralizing the current MDL, indicating that similar claims and patents might be litigated.

6. Settlement, Dismissal, Judgment, or Appeal

• The MDL is currently ongoing.
• Settlements in PTAB Proceedings: There have been partial settlements in related PTAB proceedings. For instance, in IPR2025-00717 and IPR2025-00718, a joint motion to terminate was filed by Petitioner WEC Energy Group, Inc. and Patent Owner Birchtech Corp. (formerly ME2C) on October 22, 2025, due to a settlement agreement. These IPRs involved U.S. Patent No. 10,926,218. The termination was granted only for WEC, while the proceedings continued for other petitioners like PacifiCorp and MidAmerican Energy Company.

7. Parallel PTAB IPR/PGR Proceedings

• Several Inter Partes Review (IPR) proceedings have been filed against Midwest Energy Emissions Corp.'s patents, including U.S. Patent No. 10,589,225.
• IPR Filings: Petitioners such as Berkshire Hathaway Energy Company and PacifiCorp have filed IPRs. For example, IPR2025-00274 was filed by Berkshire Hathaway Energy Company et al. against MES, Inc. (an entity related to ME2C) on January 16, 2025. Other IPRs noted in docket entries include IPR2025-00422, IPR2025-00424 (specifically mentioning USP 10,589,225).
• Effect on Litigation: The district court denied motions to stay the MDL pending PTAB institution decisions, indicating that the litigation would proceed unless and until the PTAB actually institutes IPRs. The existence of these IPRs suggests ongoing challenges to the validity of the asserted patents, which could significantly impact the MDL if instituted.

Here is the counsel of record representing the plaintiff, Midwest Energy Emissions Corp., in the "In Re: Midwest Energy Emissions Corp. Patent Litigation" (4:24-md-03132) case:

Firm: Caldwell Cassady & Curry, LLP
Office Location: Dallas, Texas

Attorneys:

• Bradley W. Caldwell

  • Role: Lead Counsel (Principal)
  • Firm: Caldwell Cassady & Curry, LLP (Dallas, Texas)
  • Relevant Patent Litigation Experience: Recognized as one of the nation's leading trial lawyers in patent infringement and complex commercial litigation, with over $3 billion in verdicts, including multiple nine-figure verdicts against Apple Inc., Microsoft, Samsung, and LG. He served as lead trial counsel for Midwest Energy Emissions Corp. in a Delaware patent infringement case, securing a $57 million verdict.

• Justin Nemunaitis

  • Role: Lead Counsel (Principal)
  • Firm: Caldwell Cassady & Curry, LLP (Dallas, Texas)
  • Relevant Patent Litigation Experience: Focuses on patent infringement disputes and complex commercial litigation. He has helped secure large patent infringement verdicts, including for VirnetX against Apple Inc., and was involved in the Midwest Energy Emissions Corp. Delaware trial. His involvement in the MDL is noted in court filings.

• Daniel R. Pearson

  • Role: Trial Counsel (Principal)
  • Firm: Caldwell Cassady & Curry, LLP (Dallas, Texas)
  • Relevant Patent Litigation Experience: A principal focusing on complex commercial litigation and patent infringement disputes, he has contributed to multiple multimillion-dollar verdicts, including the $57 million verdict for Midwest Energy Emissions Corp. in Delaware.

• Adrienne Dellinger

  • Role: Trial Counsel (Principal)
  • Firm: Caldwell Cassady & Curry, LLP (Dallas, Texas)
  • Relevant Patent Litigation Experience: An accomplished patent litigator involved in high-stakes civil disputes, she served as trial counsel in the $57 million patent infringement case for Midwest Energy Emissions Corp. in Delaware and other patent infringement cases with significant verdicts.

• Aisha Mahmood Haley

  • Role: Trial Counsel (Principal)
  • Firm: Caldwell Cassady & Curry, LLP (Dallas, Texas)
  • Relevant Patent Litigation Experience: A principal at the firm focusing on complex business litigation and patent disputes, she was an integral member of the trial team that secured the $57 million verdict for Midwest Energy Emissions Corp. in Delaware. She has extensive experience in all phases of high-value litigation.

• Richard Cochrane

  • Role: Trial Counsel (Associate)
  • Firm: Caldwell Cassady & Curry, LLP (Dallas, Texas)
  • Relevant Patent Litigation Experience: An associate focusing on complex business litigation and patent disputes, he played a vital role in the $57 million verdict for Midwest Energy Emissions Corp. in Delaware and other significant patent infringement trials.

The above attorneys from Caldwell Cassady & Curry are acting as lead counsel and trial counsel for Midwest Energy Emissions Corp. in this patent litigation. No other plaintiff counsel from other firms or in-house counsel were explicitly identified in the available search results for this specific MDL case.

Here is the counsel of record representing the defendants in the "In Re: Midwest Energy Emissions Corp. Patent Litigation" (4:24-md-03132) case:

Given the large number of defendants, various law firms represent different parties. The following attorneys and firms have been identified from available public docket information and related proceedings:

For Ameren Corp., Union Electric Co. (d/b/a Ameren Missouri), Evergy, Inc., Evergy Metro, Inc., Evergy Missouri West, Inc., and Evergy Kansas Central, Inc.:

• Robert M. Evans, Jr.
  • Role: Counsel for Ameren Corp. and Evergy entities.
  • Firm: Unspecified in search results, but associated with the defense of Ameren Corp. and Evergy, Inc.
  • Relevant Patent Litigation Experience: Information not readily available in the provided search results.
• Richard Bennett Walsh, Jr.
  • Role: Counsel for Ameren Corp. and Evergy entities.
  • Firm: Unspecified in search results, but associated with the defense of Ameren Corp. and Evergy, Inc.
  • Relevant Patent Litigation Experience: Information not readily available in the provided search results.
• Megan LaDriere White
  • Role: Counsel (granted Pro Hac Vice on February 14, 2025).
  • Firm: Information not readily available in the provided search results.
  • Relevant Patent Litigation Experience: Information not readily available in the provided search results.
• Paul R. Morico
  • Role: Counsel (granted Pro Hac Vice on February 14, 2025).
  • Firm: Baker Botts L.L.P.
  • Relevant Patent Litigation Experience: Known for patent litigation; his firm, Baker Botts L.L.P., is a prominent intellectual property firm.
• Local Counsel for Evergy entities (and potentially others):
  • Firm: Belin McCormick, P.C. (Des Moines, Iowa)
  • Relevant Patent Litigation Experience: Often serves as local counsel in Iowa federal court cases.

For Berkshire Hathaway Energy Company, MidAmerican Energy Company, and PacifiCorp:

• Richard W. Mark
  • Role: Counsel. He is listed as a "Challenger" for Berkshire Hathaway Energy Co. in related cases within the MDL.
  • Firm: Gibson Dunn & Crutcher LLP.
  • Relevant Patent Litigation Experience: Has 21 years of experience in patent law, with practice areas including chemical, mechanical engineering, manufacturing, transportation, e-commerce, and design.

For Interstate Power and Light Company and Wisconsin Power and Light Company:

• Michelle M. Kemp
  • Role: Lead Counsel for Petitioners Interstate Power and Light and Wisconsin Power and Light in related PTAB proceedings.
  • Firm: Caldwell Cassady & Curry P.C. (Dallas, TX). Note: This is the same firm as the plaintiff's counsel, which is unusual. This indicates Ms. Kemp may be representing these entities in their capacity as Petitioners in IPRs against the patent owner, rather than as defendants in the MDL. The provided search result shows her listed under "Counsel for Petitioners Interstate Power and Light and Wisconsin Power and Light" in a PTAB document and a Caldwell Cassady & Curry address.
  • Relevant Patent Litigation Experience: Information not readily available in the provided search results.
• Hamad M. Hamad
  • Role: Counsel for Petitioners Interstate Power and Light and Wisconsin Power and Light in related PTAB proceedings.
  • Firm: Caldwell Cassady & Curry P.C. (Dallas, TX). Similar to Ms. Kemp, this appears to be in his capacity as IPR counsel for the Petitioners.
  • Relevant Patent Litigation Experience: Information not readily available in the provided search results.

It's important to note that while Michelle M. Kemp and Hamad M. Hamad are listed with Caldwell Cassady & Curry (the plaintiff's firm), their appearance is in the context of representing Interstate Power and Light and Wisconsin Power and Light as Petitioners in PTAB proceedings challenging the patent owner (Birchtech Corp., formerly ME2C). This highlights the complex, multi-faceted nature of patent disputes. Interstate Power and Light Company and Wisconsin Power and Light Company were also dismissed from the MDL due to settlement.