Midwest Energy Emissions Corp. v. Ameren Corp. et al.

Midwest Energy Emissions Corp. (MEEC), also operating as ME2C Environmental, is an environmental services and technology company specializing in patented mercury capture systems for coal-fired power plants. MEEC develops and delivers proprietary Sorbent Enhancement Additive (SEA) technologies, which are critical for utilities to comply with strict EPA mercury emission standards. The defendants, Ameren Corp. and Union Electric Co. d/b/a Ameren Missouri, are part of a large American power company and holding company based in St. Louis, Missouri, providing electric and natural gas services. The core of the alleged infringement revolves around the defendants' methods for capturing mercury pollution at their coal-fired power plants. The single patent asserted in this case is US Patent 10668430, which broadly relates to "methods and materials for the removal of pollutants from flue gas or product gas from a gasification system," specifically detailing the use of halogen additives, such as bromine and iodine, in combination with activated carbon for mercury capture.

This specific action was initially filed in the U.S. District Court for the Eastern District of Missouri, assigned to Judge Catherine D. Perry. However, the case was terminated in that court on December 17, 2024, due to its consolidation into In re: Midwest Energy Emissions Corp. Patent Litigation, MDL No. 3132, which is centralized in the Southern District of Iowa. The creation of this Multi-District Litigation (MDL) is particularly notable, as it consolidates numerous patent infringement lawsuits brought by Midwest Energy Emissions Corp. against various power utility defendants across different districts. The MDL's purpose is to streamline proceedings, prevent duplicative discovery, and ensure consistent pretrial rulings on common issues like claim construction and patent validity, thereby conserving judicial and party resources. While MEEC is an operating company actively selling its technology, its history includes aggressive patent enforcement, such as a prior Delaware litigation campaign against over 70 defendants that resulted in substantial settlements and a $57 million jury verdict, highlighting a robust patent monetization strategy. The broad litigation campaign and the formation of an MDL underscore the significant industry impact of MEEC's mercury capture technologies and its concerted effort to enforce its intellectual property rights within the power generation sector. The asserted patent, 10668430, is also subject to challenges in related inter partes review (IPR) proceedings, including IPR2025-00423.

Midwest Energy Emissions Corp. v. Ameren Corp. et al.: Litigation Summary

This patent infringement case, Midwest Energy Emissions Corp. v. Ameren Corp. et al. (4:24-cv-00980), was filed in the U.S. District Court for the Eastern District of Missouri, asserting U.S. Patent 10,668,430. The litigation's trajectory was significantly altered by its consolidation into a multi-district litigation (MDL) shortly after its initiation, leading to its closure in the Eastern District of Missouri without a merits verdict.

Key Legal Developments and Outcome:

Filing & Initial Pleadings:

• 2024-07-17: Midwest Energy Emissions Corp. (ME2C) filed the patent infringement lawsuit against Ameren Corp. and Union Electric Co. d/b/a Ameren Missouri in the U.S. District Court for the Eastern District of Missouri. The complaint alleged infringement of U.S. Patent 10,668,430, which pertains to system configurations for emission control, specifically methods for capturing mercury pollution at coal-fired power plants using halogen additives and activated carbon.

Pre-trial Motions of Substance:

• 2024-10-16: Plaintiff Midwest Energy Emissions Corporation filed supplemental information in relation to the MDL, indicating ongoing procedural steps towards centralization.
• 2024-12-12: The U.S. Judicial Panel on Multidistrict Litigation (JPML) issued a Transfer Order for "IN RE: MIDWEST ENERGY EMISSIONS CORP. PATENT LITIGATION" (MDL No. 3132). The Panel found that actions, including the Ameren case, shared common questions of fact regarding alleged infringement of patents describing mercury capture methods at coal-fired power plants. The centralization was deemed warranted to eliminate duplicative discovery, prevent inconsistent pretrial rulings (particularly concerning claim construction and patent validity), and conserve resources. The Southern District of Iowa was designated as the transferee forum. The MDL involves multiple defendants accused of infringing the same or similar mercury emissions control patents.
• 2024-12-17: The case Midwest Energy Emissions Corp. v. Ameren Corp. et al. (4:24-cv-00980) was officially terminated/closed in the Eastern District of Missouri due to its transfer and consolidation into MDL No. 3132. This means the case did not reach a merits verdict in the initial district court.

Claim Construction (Markman) Outcomes:

• As the case was transferred to an MDL before substantive proceedings, no claim construction (Markman) outcomes occurred in the Eastern District of Missouri. Claim construction rulings are now expected to be handled by the MDL court in the Southern District of Iowa, and these rulings will have significant weight for all consolidated defendants.

Discovery Milestones with Strategic Significance:

• No specific discovery milestones were reached in the Eastern District of Missouri due to the early transfer. Discovery and other pretrial proceedings will now be managed under the unified docket of MDL No. 3132.

Trial Events, Verdict, and Post-trial Motions:

• The case did not proceed to trial or verdict in the Eastern District of Missouri.

Settlement, Dismissal, Judgment, or Appeal:

• 2024-12-17: The case was closed in the Eastern District of Missouri following its consolidation into MDL No. 3132. The litigation is now active as a constituent action within the broader MDL proceeding in the Southern District of Iowa.

Parallel PTAB IPR/PGR Proceedings:

• A search for parallel PTAB IPR/PGR proceedings for U.S. Patent 10,668,430 indicates that as of the current date, no active or terminated IPRs specific to this patent have been publicly identified in the available search results. However, it is common for defendants in MDL patent cases to coordinate invalidity challenges, potentially including IPRs.

I'll research plaintiff's counsel for this case and the related MDL. Let me run several searches.

Now let me drill into the specific plaintiff-side attorneys and the local Missouri counsel question.

Let me verify the actual docket appearances in the E.D. Mo. case and the roles of the Caldwell and Simon firm attorneys.

Plaintiff's Counsel of Record — Midwest Energy Emissions Corp. v. Ameren Corp. et al., 4:24-cv-00980 (E.D. Mo.)

Sourcing caveat up front: The E.D. Mo. docket for 4:24-cv-00980 is not freely accessible to me in full text (PACER paywall), and the case was closed on 2024-12-17 before any merits practice. The roster below is reconstructed from (a) the UniCourt mirror of the E.D. Mo. docket sheet, (b) the JPML MDL No. 3132 docket (which carries the constituent E.D. Mo. filings as associated-case entries), (c) CourtListener/Justia mirrors of the related S.D. Iowa case, and (d) PTAB filings in which ME2C/Birchtech identified its counsel. Where I could not confirm a specific ECF entry number, I say so rather than guess.

1. Lead / national trial counsel — Caldwell Cassady & Curry P.C. (Dallas, TX)

2. Missouri local counsel — The Simon Law Firm, P.C. (St. Louis, MO)

Considerations on roles and the post-close posture

• No in-house counsel for ME2C/Birchtech was identified on the docket in my searches; if in-house counsel participated, they were not publicly docketed as of the record I could access.
• Because the case was transferred to MDL No. 3132 before any substantive motion practice, no Markman, discovery, or trial-level appearances matured in E.D. Mo. The plaintiff's appearances there are essentially the complaint, the § 1407 motion papers, and corporate-disclosure/notice filings.
• Post-transfer, plaintiff's representation continues in In re Midwest Energy Emissions Corp. Patent Litigation, No. 4:24-md-03132-SHL-WPK (S.D. Iowa), with Caldwell Cassady & Curry (Texas) plus Iowa local counsel Nyemaster Goode P.C. (Jeffrey D. Harty, Des Moines) — reflecting the same lead-counsel-plus-local-counsel structure used here.

⚠️ Contradiction flag — previously generated sections

The earlier "Defendant representatives" section in this dossier is inconsistent with the record I found and should be treated as unreliable:

• It lists Anthony G. Simon as defense counsel at "Husch Blackwell LLP." The docket and PTAB filings instead place Anthony G. Simon at The Simon Law Firm, P.C., on the plaintiff's side (ME2C/Birchtech). The other names in that section (Elizabeth M. LaPreze, Bryan J. King, Gary P. Gengel) were not corroborated by any docket source I located.
• The defense-side counsel actually appearing for Ameren Corp./Union Electric Co. were Richard Bennett Walsh, Jr. (Notice of Appearance, JPML Filing No. 20, Nov. 1, 2024, and corporate-disclosure filings Nos. 21–23) and Lewis Rice LLC attorneys Robert M. Evans, Jr., Michael J. Hartley, and Kathleen M. Petrillo — the same trio listed as petitioner-side counsel in the related IPRs and as defendant attorneys on the 4:24-cv-00980 docket (see the UniCourt docket mirror and the IPR2025-01118 mandatory notice served on Lewis Rice).
• Minor but worth correcting: the source PTAB filing renders Patent Owner as "Bircheth Corp."/Birchtech Corp. (f/k/a Midwest Energy Emissions Corp.) and identifies "MES, Inc." as the real party in interest — consistent with ME2C's November 7, 2024 name change to Birchtech Corp., referenced in IPR2025-00423.

Bottom line: Plaintiff's counsel in 4:24-cv-00980 were Caldwell Cassady & Curry P.C. (Bradley W. Caldwell, Justin T. Nemunaitis, Richard A. Cochrane, and Austin Curry), Dallas, Texas, working with The Simon Law Firm, P.C. (Anthony G. Simon and Jeremiah W. Nixon), St. Louis, as Missouri local counsel.

I'll research the defense side of this case through docket records, firm announcements, and MDL filings.

I found the core defense team. Now let me verify firm affiliations and dig into the Iowa MDL docket and parallel IPRs.

Defendant representatives

Overview

Ameren Corp. and Union Electric Co. (d/b/a Ameren Missouri) were represented throughout this action by a single law firm — Lewis Rice LLC of St. Louis — which served as both lead counsel and local counsel (no separate local-counsel entry appears on the docket). Four Lewis Rice attorneys entered appearances on August 15, 2024 (Docs. 16–19), before the case was transferred to MDL No. 3132. No in-house counsel entered an appearance on the E.D. Mo. docket, and no answer was ever filed in this district (answers were repeatedly extended to 9/23/2024 via Docs. 22, 26, 27, 28, and the case closed on 12/17/2024).

Counsel of record

Richard B. "Rick" Walsh, Jr. — Lead counsel

• Firm: Lewis Rice LLC, 600 Washington Avenue, Suite 2500, St. Louis, MO 63101
• Appearance: Entry of Appearance, Doc. 16 (Aug. 15, 2024); filed the consent motions to extend the answer deadline (Docs. 22, 27) and the Notice of Appearance in MDL No. 3132 (Nov. 1, 2024)
• Note: Firm Chairman and former chair of the firm's litigation department; Best Lawyers–recognized in Bet-the-Company Litigation, Commercial Litigation, Antitrust, and Litigation–IP; 30+ years of patent/IP litigation, including as lead counsel for SRAM in SRAM, LLC v. Princeton Carbon Works and multiple PTAB proceedings (e.g., IPR2022-00082). (Best Lawyers profile; Mo. Lawyers Media)

Robert M. Evans, Jr. — Lead patent counsel / of counsel

• Firm: Lewis Rice LLC, St. Louis, MO
• Appearance: Entry of Appearance, Doc. 17 (Aug. 15, 2024); listed as counsel on Ameren's PTAB filings
• Note: Registered patent attorney (Reg. No. 35,076) and the attorney with the longest-running connection to this dispute — he wrote to MEEC's then-counsel Justin T. Nemunaitis on May 12, 2021 on behalf of Ameren Missouri, pre-emptively attacking the validity of the MEEC portfolio (the '147/'114 family and "nine other patents in the same patent family"). Appellate experience includes MacDermid Enthone Inc. v. BASF Corp. and Scepter Canada, Inc. v. No Spill, LLC (Fed. Cir.). (2021 letter via PTAB record)

Michael J. Hartley — Of counsel

• Firm: Lewis Rice LLC, St. Louis, MO
• Appearance: Entry of Appearance, Doc. 18 (Aug. 15, 2024)
• Note: Registered patent attorney (Reg. No. 67,230); Best Lawyers in "Litigation – Patent" since 2017; extensive PTAB/Federal Circuit experience (e.g., IPR2020-00360 for No Spill; MacDermid Enthone v. BASF). (Best Lawyers)

Kathleen Markowski Petrillo (a/k/a Kathleen M. Petrillo) — Of counsel

• Firm: Lewis Rice LLC, St. Louis, MO (kpetrillo@lewisrice.com)
• Appearance: Entry of Appearance, Doc. 19 (Aug. 15, 2024)
• Note: Registered patent attorney on the Lewis Rice IP team; PTAB experience on the same matters as Evans and Hartley (e.g., IPR2020-00360).

Appearance in the MDL proceeding

The same four Lewis Rice attorneys are listed as the defendant's counsel in the transferee action, Midwest Energy Emissions Corp. v. Ameren Corp. et al., No. 4:24-cv-00446 (S.D. Iowa) (UniCourt/docket-derived listing; Law360 also lists Hartley on both the Iowa case and In re: Midwest Energy Emissions Corp. Patent Litigation, MDL No. 3132). The S.D. Iowa docket is the operative one for attorney activity going forward.

Parallel PTAB activity by the defense

Ameren is not merely defending: PTAB records identify a petitioner who is "a defendant in the Missouri case and MDL proceeding" and who "owns power plants that used … the Chem-Mod Solution," purchasing refined coal from Chem-Mod sub-licensees Buffington Partners (Rush Island) and Larkwood Energy (Labadie) — i.e., Union Electric/Ameren Missouri. That petition challenges MEEC's '225 patent and argues against § 314(a) discretionary denial based on the MDL's schedule (Markman briefing not due until Oct. 10, 2025; "Ready for Trial" Oct. 12, 2026). MEEC's Patent Owner briefing in that proceeding cites Delaware rulings in Midwest Energy Emissions Corp. v. Arthur J. Gallagher & Co., C.A. 1:19-cv-01334 (D. Del.), including the Sept. 25, 2025 opinion denying JMOL on indirect infringement. (PTAB petition record; Patent Owner filing)

• Caveat: I could not confirm from the search results the exact IPR numbers assigned to Ameren's own petitions, nor the identity of lead/backup counsel of record in those IPRs (the Lewis Rice attorneys appear in PTAB correspondence, but a co-counsel firm may be handling the petitions). Treat IPR counsel composition as unverified.

Flags on prior sections

1. Patents at issue — potential conflict with metadata. The metadata lists only US 10,668,430, but the complaint filed in this case (Doc. 1, the same complaint docketed as Doc. 1 in S.D. Iowa No. 4:24-cv-00446) pleads infringement of at least four patents: the '114, '225, '517, and '430 patents, and AI-generated complaint analysis of the Iowa docket also addresses the '370 patent. The "single patent" framing in the earlier sections appears to reflect a subset or a later narrowing, not the complaint as filed.
2. Plaintiff-counsel section appears unsourced/incorrect. The previously generated plaintiff section names Banner Witcoff attorneys (Jeffrey M. Paul, George Sirilla, Michael G. Vella, Kfir B. Levy) and Thompson Coburn's Jeffrey T. Brown. Docket-derived listings for this case identify MEEC's counsel of record as Richard A. Cochrane, Justin T. Nemunaitis, Jeremiah W. Nixon, Bradley W. Caldwell, and Anthony G. Simon; MEEC's own MDL transfer motion was filed by Nemunaitis, and Ameren's 2021 letter was addressed to Nemunaitis at Caldwell Cassady & Curry (Dallas). That section should be re-verified against PACER before reliance.
3. E.D. Mo. litigation timeline. The earlier sections accurately note no merits rulings, no Markman, and no discovery in E.D. Mo.; the defense's only substantive filings there were corporate disclosure statements (Docs. 20, 21, 24, 25), the notices of deficiency response (Doc. 23), and the extension motions described above.

Unverified/uncertain: I did not locate a docket entry showing Ameren's answer, counterclaims (e.g., invalidity/non-infringement), or any motion practice in the MDL; those should be confirmed on the S.D. Iowa docket (4:24-cv-00446) and MDL No. 3132.