Midwest Energy Emissions Corp. v. Ameren Corporation

Midwest Energy Emissions Corp. (ME2C), an environmental technologies firm now also known as Birchtech Corp., initiated a patent infringement lawsuit against Ameren Corporation, a major American electric and natural gas utility company that operates coal-fired power plants in Missouri and Illinois. The core of the dispute centers on ME2C's "SEA® (Sorbent Enhancement Additive) Technologies," which are designed to capture mercury pollution from coal-fired power plants. Ameren is accused of infringing ME2C's patents by allegedly employing methods for reducing mercury emissions that utilize a combination of halogen additives, such as bromine and iodine, and activated carbon.

The patent at issue in this specific case, U.S. Patent No. 10,589,225, is one of several patents sharing the title "Sorbents for the Oxidation and Removal of Mercury" that are being asserted by ME2C in similar litigations. These patents generally describe methods for controlling mercury emissions from power plants, often involving the use of bromine-enhanced coal (or "refined coal") alongside sorbents like activated carbon to maintain mercury content in cleaned gas at or below desired levels. The lawsuits assert that the defendant's use of these mercury emissions reduction technologies infringes upon ME2C's intellectual property rights.

The case, initially filed in the U.S. District Court for the Eastern District of Missouri (4:24-cv-00980), has since been consolidated into multidistrict litigation (MDL No. 4:24-md-3132) in the U.S. District Court for the Southern District of Iowa, presided over by Judge Stephen H. Locher. This centralization by the Judicial Panel on Multidistrict Litigation (JPML) aims to streamline the litigation by consolidating pretrial proceedings, including discovery and claim construction, for multiple similar lawsuits filed by ME2C against various utility companies. The establishment of an MDL signifies a coordinated patent enforcement campaign by ME2C, building on a history of successful patent litigation, including a prior $57 million verdict in a similar Delaware action against other power plant operators. The ongoing litigation is notable for its industry impact, targeting environmental control technologies crucial for coal-fired power plants to meet regulations like the Mercury and Air Toxics Standards (MATS), and for ME2C's strategic, multi-defendant approach to patent assertion.

Key Legal Developments and Outcome for Midwest Energy Emissions Corp. v. Ameren Corporation

The patent infringement suit Midwest Energy Emissions Corp. v. Ameren Corporation, initially filed as case number 4:24-cv-00980 in the U.S. District Court for the Eastern District of Missouri, was later consolidated into multidistrict litigation (MDL) No. 4:24-md-3132 in the Southern District of Iowa. The MDL, titled In re Midwest Energy Emissions Corp. Patent Litigation, was established on December 17, 2024, by the Judicial Panel on Multidistrict Litigation. The lawsuit involves U.S. Patent No. 10,589,225, among others, pertaining to methods for capturing mercury emissions from coal-fired power plants.

Filing & Initial Pleadings:

• 2024: Midwest Energy Emissions Corp. (ME2C) filed the patent infringement suit against Ameren Corporation in the Eastern District of Missouri.
• 2024-11-06: In the originating Eastern District of Missouri case (4:24-cv-00980), a motion to stay discovery pending a decision by the Judicial Panel on Multidistrict Litigation (JPML) on transfer was granted.
• 2024-12-12: The JPML issued an order to transfer several related cases, including the Ameren case, to the Southern District of Iowa for consolidation.
• 2024-12-17: The case was officially transferred from the Eastern District of Missouri to the Southern District of Iowa and consolidated into MDL No. 4:24-md-3132. Ameren Corporation is listed as a defendant in the MDL. Other defendants within the MDL, such as MidAmerican Energy Company, filed answers with affirmative defenses and counterclaims.

Pre-trial Motions of Substance:

• 2025-05-22: Within the MDL, several defendants filed motions to stay the proceedings, citing their intention to file, or having already filed, applications with the Patent Trial and Appeal Board (PTAB) for inter partes review (IPR) of the validity of the patents-in-suit. The Court denied these motions to stay without prejudice, indicating it would not impose a stay before the PTAB had decided whether to institute review proceedings.
• 2025-05-22: Defendants' joint motion to compel ME2C to file amended initial infringement contentions, arguing they were too numerous and lacked specificity, was denied. The Court found ME2C's contentions sufficient to provide notice of the claims.

Parallel PTAB IPR/PGR Proceedings:

• Several IPR proceedings have been initiated against patents involved in the broader Midwest Energy Emissions Corp. Patent Litigation, though a specific IPR for U.S. Patent No. 10,589,225 was not explicitly detailed in the search results.
• 2025-06-06: Union Electric Company, identifying Ameren Corporation as a real party-in-interest, filed an IPR petition (IPR2025-00423) challenging claims of U.S. Patent No. 10,343,114.
• 2025-09-08: The PTAB instituted an inter partes review (IPR2025-00278) for U.S. Patent No. 10,343,114, based on a petitioner's asserted grounds of unpatentability. Another IPR (IPR2025-00274) was also filed concurrently against the same patent.
• 2025-01-24: An IPR (IPR2025-00281) challenging claims of U.S. Patent No. 10,596,517 was filed.

Current Posture:
The case Midwest Energy Emissions Corp. v. Ameren Corporation remains active as part of MDL No. 4:24-md-3132 in the Southern District of Iowa. As of the most recent information, the court has denied motions to stay pending PTAB institution decisions and denied motions to compel more specific infringement contentions. There is no information indicating a claim construction (Markman) hearing has concluded, significant discovery milestones beyond the contentions dispute, trial events, verdict, settlement, or final judgment specifically for the Ameren case or the MDL as a whole. The various IPRs initiated on related patents will likely influence the course of the litigation.

The plaintiff, Midwest Energy Emissions Corp., is represented by the following counsel:

• Bradley W. Caldwell

  • Role: Lead Trial Counsel
  • Firm: Caldwell Cassady & Curry P.C., Dallas, TX
  • Experience: Caldwell has served as lead trial counsel for Midwest Energy Emissions Corp. since 2018 and has secured multiple multi-million dollar patent infringement verdicts, including a $57 million verdict for Midwest Energy Emissions Corp. in a Delaware patent infringement case.

• Justin T. Nemunaitis

  • Role: Lead Counsel (presented witnesses at trial in a related Delaware case)
  • Firm: Caldwell Cassady & Curry P.C., Dallas, TX
  • Experience: Nemunaitis has been part of the trial team for Midwest Energy Emissions Corp. in significant patent infringement litigation and is frequently listed on MDL filings for the plaintiff.

• Daniel R. Pearson

  • Role: Lead Counsel (presented witnesses at trial in a related Delaware case)
  • Firm: Caldwell Cassady & Curry P.C., Dallas, TX
  • Experience: Pearson was a key member of the trial team that secured a $57 million patent infringement verdict for Midwest Energy Emissions Corp.

• Adrienne R. Dellinger

  • Role: Counsel
  • Firm: Caldwell Cassady & Curry P.C., Dallas, TX
  • Experience: Dellinger played a vital role in the Caldwell Cassady & Curry team that won the $57 million patent infringement verdict for Midwest Energy Emissions Corp.

• Aisha Mahmood Haley

  • Role: Counsel
  • Firm: Caldwell Cassady & Curry P.C., Dallas, TX
  • Experience: Haley was part of the Caldwell Cassady & Curry team that secured a significant patent infringement verdict for Midwest Energy Emissions Corp.

• Richard A. Cochrane

  • Role: Counsel
  • Firm: Caldwell Cassady & Curry P.C., Dallas, TX
  • Experience: Cochrane contributed to the Caldwell Cassady & Curry team's success in the Midwest Energy Emissions Corp. patent litigation.

• Jeremiah W. Nixon

  • Role: Local Counsel
  • Firm: The Simon Law Firm PC, St. Louis, MO (based on firm's general location and context of original filing in Eastern District of Missouri)
  • Experience: Listed as counsel for Midwest Energy Emissions Corp. in a case consolidated into the MDL.

• Anthony G. Simon

  • Role: Local Counsel
  • Firm: The Simon Law Firm PC, St. Louis, MO (based on firm's general location and context of original filing in Eastern District of Missouri)
  • Experience: Listed as counsel for Midwest Energy Emissions Corp. in a case consolidated into the MDL.

• James M. Lennon

  • Role: Local Counsel
  • Firm: Devlin Law Firm LLC, Wilmington, DE
  • Experience: Listed as counsel for Midwest Energy Emissions Corp. in the related Delaware patent infringement case.

• Peter Akawie Mazur

  • Role: Local Counsel
  • Firm: Devlin Law Firm LLC, Wilmington, DE
  • Experience: Listed as counsel for Midwest Energy Emissions Corp. in the related Delaware patent infringement case.

Defendant Ameren Corporation is represented by the following counsel:

• Richard Bennett Walsh, Jr.

  • Role: Counsel
  • Firm: Lewis Rice, St. Louis, Missouri
  • Experience Note: Richard Walsh has filed corporate disclosure statements on behalf of Ameren Corp. and Union Electric Co. in this litigation. He is also noted as counsel for Union Electric Company in related Inter Partes Review (IPR) proceedings.

• Robert M. Evans, Jr.

  • Role: Counsel
  • Firm: Lewis Rice, St. Louis, Missouri
  • Experience Note: Robert M. Evans, Jr. is listed as counsel for Ameren Corp. and Union Electric Co. in the consolidated MDL and the original case. His firm, Lewis Rice, has an office in St. Louis, Missouri.

The original case, 4:24-cv-00980, was filed in the U.S. District Court for the Eastern District of Missouri on July 17, 2024, and was subsequently consolidated into MDL No. 4:24-md-3132 in the U.S. District Court for the Southern District of Iowa on December 17, 2024. Therefore, the counsel listed above are appearing in the consolidated MDL.