Union Electric Co. v. Birchtech Corp.

This case involves an Inter Partes Review (IPR) before the Patent Trial and Appeal Board (PTAB) between petitioner Union Electric Co. and patent owner Birchtech Corp. Union Electric Co., operating as Ameren Missouri, is a major electric power utility that provides electric and natural gas services in central and eastern Missouri, relying on various energy sources, including coal, for electricity generation. Birchtech Corp. (formerly Midwest Energy Emissions Corp.) is a clean technology company specializing in advanced activated carbon technologies for environmental solutions, particularly focused on capturing mercury emissions from coal-fired power plants and removing "forever chemicals" like PFAS from water. Birchtech has actively leveraged its intellectual property through extensive patent litigation against numerous utility and refined coal companies, suggesting a strategy akin to a patent assertion entity. The patent at issue, US 10,596,517, generally describes "Sorbents for the oxidation and removal of mercury" from flue gases produced during the combustion or gasification of fossil fuels, such as coal. This patent, and related ones, are part of Birchtech's "SEA® (Sorbent Enhancement Additive) Technologies," which are at the core of their enforcement actions against power utilities.

This IPR, IPR2025-01117, was filed at the Patent Trial and Appeal Board and uniquely reached a "Not Instituted - Procedural" status. This procedural denial is particularly notable in the current landscape of PTAB proceedings, given recent policy changes by the U.S. Patent and Trademark Office (USPTO) Director. These changes, enacted in late 2025, grant the Director personal authority over institution decisions and include proposed rules that can bar IPRs based on prior litigation outcomes or specific procedural defects, such as issues with identifying real parties-in-interest. The timing of this IPR means it falls under these stricter guidelines, and its procedural dismissal could signify an adherence to these new policies or a technical flaw in the petition that prevented a review on the merits.

The case is significant as it ties into a broader, aggressive patent enforcement campaign by Birchtech, which has initiated multiple patent infringement lawsuits against power utilities since 2019, securing substantial settlements and a significant $78 million judgment in a Delaware district court case in late 2025. Union Electric Co. itself was named as a defendant in a related patent infringement lawsuit filed by Birchtech's division, ME2C Environmental, in July 2024, specifically concerning mercury emissions reduction technologies. Therefore, the IPR is part of Union Electric's defense strategy to challenge the validity of Birchtech's patents, which have considerable industry impact in the critical environmental compliance sector for coal-fired power generation. The procedural non-institution of this IPR could influence future challenges to Birchtech's patent portfolio by other utilities.

Background of the Litigation

Birchtech Corp. (as plaintiff/patent owner) has been involved in extensive patent infringement litigation concerning its "SEA® (Sorbent Enhancement Additive) Technologies" for mercury emissions reduction. This litigation commenced with an initial lawsuit in July 2019 against 43 defendants in the U.S. District Court of Delaware. While that initial litigation culminated in a $57 million jury verdict in March 2024 against "CERT Defendants" (refined coal operating companies), with a final judgment increasing to approximately $78 million by December 2025, the specific case involving Union Electric Co. as a defendant falls under a separate, later-filed series of lawsuits.

In July 2024, Birchtech Corp. filed three separate lawsuits against a total of 14 defendants, including major coal-fired utilities, in U.S. District Courts in Arizona, Iowa, and Missouri. These cases were later consolidated and centralized in the U.S. District Court for the Southern District of Iowa in December 2024, forming a multidistrict litigation (MDL) identified as Case 4:24-md-03132-SHL-WPK. Union Electric Co. and Ameren Corporation are among the defendants in this consolidated lawsuit and are accused of infringing five patents, including U.S. Patent No. 10,596,517.

Key Legal Developments and Outcome

The key legal developments for the patent infringement litigation involving Union Electric Co. and the associated Inter Partes Review (IPR) are as follows:

1. District Court Litigation - Filing & Initial Pleadings (Southern District of Iowa, MDL Case 4:24-md-03132-SHL-WPK)

• July 2024: Birchtech Corp. initiated three separate patent infringement lawsuits against 14 defendants, including Union Electric Co., in various district courts (Arizona, Iowa, and Missouri). These lawsuits accused the defendants of infringing patents related to Birchtech's mercury emissions reduction technologies.
• December 2024: The Judicial Panel on Multidistrict Litigation consolidated and centralized these three separate lawsuits into the U.S. District Court for the Southern District of Iowa under MDL Case No. 4:24-md-03132-SHL-WPK.
• May 22, 2025: A court document in the Iowa MDL noted that Union Electric Co. and Ameren Corporation ("Union Electric") intended to file petitions for inter partes review (IPR) for five of the patents they were accused of infringing, including U.S. Patent No. 10,596,517. The defendants in this MDL also filed a joint motion to compel supplemental infringement contentions from Birchtech, arguing that too many claims were identified without sufficient specificity, which the court denied.

2. Parallel PTAB IPR Proceedings - IPR2025-01117

• April 1, 2025: An IPR trial proceeding was filed before the Patent Trial and Appeal Board (PTAB) related to patent 10596517, though the specific petition date for IPR2025-01117 by Union Electric Co. is listed as June 6, 2025.
• June 6, 2025: Union Electric Co. filed the petition for Inter Partes Review, IPR2025-01117, challenging U.S. Patent No. 10,596,517, owned by Birchtech Corp.
• November 20, 2025: The PTAB issued a decision in IPR2025-01117 stating that the petition was "Not Instituted - Procedural."
  • Significance of "Not Instituted - Procedural": This outcome, shared by several other IPRs filed by Union Electric Co. and other entities against Birchtech (e.g., IPR2025-01323, IPR2025-01324, IPR2025-00718), aligns with a broader trend where the Director of the USPTO has limited the institution of parallel IPR petitions, particularly when multiple petitions challenge the same claims or present too many grounds inefficiently. In a related set of IPRs, PacifiCorp, et al. v. Birchtech Corp. (IPR2025-00687, -00688, -00717, -00718), the Director vacated institution decisions in January 2026, finding that the Board abused its discretion by instituting two IPRs for each of two challenged patents, emphasizing that one petition should generally be sufficient. While IPR2025-01117 is not explicitly mentioned in the Director's review documents found, its "Not Instituted - Procedural" outcome on the same date as other similar decisions suggests it was likely subject to similar discretionary denial reasoning related to petition redundancy or efficiency concerns.

3. Pre-trial Motions of Substance (Iowa MDL)

• Given the relatively recent consolidation of the Iowa MDL (December 2024) and the IPR institution decision (November 2025), it is likely that motions to stay the district court litigation pending the outcome of IPRs were filed. However, specific details about such motions for Union Electric Co. in the Iowa MDL were not found in the provided search results. The denial of institution in the IPR would generally allow the district court litigation to proceed without a stay based on that specific IPR.

4. Final Disposition / Present Posture

• The Iowa MDL (4:24-md-03132-SHL-WPK) remains active. As of December 2025, the consolidated Iowa lawsuit included two remaining defendants after others reached license agreements with Birchtech. In February 2025, Birchtech also filed a new patent infringement lawsuit against Evergy, Inc. and related entities in the Western District of Missouri, which was then transferred to the Southern District of Iowa, likely joining the MDL.
• The IPR challenging patent 10596517, IPR2025-01117, concluded with a "Not Instituted - Procedural" decision on November 20, 2025. This means the PTAB did not proceed to a full review of the patentability of the challenged claims in this particular IPR.

Despite aggressive web searches against PTAB dockets, the USPTO Open Data Portal, and legal news sources, the specific counsel of record for Union Electric Co. in IPR2025-01117 could not be explicitly identified from publicly available information.

The case status of "Not Instituted - Procedural" suggests that the Inter Partes Review did not proceed to the merits stage, which often means that public records regarding detailed counsel appearances beyond the initial petition filing may be limited or not readily accessible through public search interfaces. While the USPTO Patent Trial and Appeal Case Tracking System (P-TACTS) is the official means for electronic filing, direct public access to counsel information for non-instituted cases can be challenging without specific document numbers or a P-TACTS account.

Searches for IPR2025-01117 on the USPTO Open Data Portal and other PTAB case tracking systems did not yield an explicit list of attorneys representing Union Electric Co. for this specific IPR. Some search results for a numerically similar IPR (IPR2025-00117) listed "Micron Technology, Inc. et al." as the Petitioner with "Jeremy Lang et al." as counsel; however, based on the authoritative case metadata provided, the petitioner for IPR2025-01117 is Union Electric Co., not Micron Technology, Inc.

Therefore, counsel for Union Electric Co. in IPR2025-01117 has not been found in the public records available.

The counsel of record for Birchtech Corp. in IPR2025-01117 has not been publicly identified in the available search results.

Inter Partes Review (IPR) IPR2025-01117, challenging patent 10596517, was filed by Union Electric Co. against Birchtech Corp. and was "Not Instituted - Procedural". Given that the petition was not instituted on procedural grounds, comprehensive filings such as a Patent Owner Preliminary Response, which would typically list counsel, may not have been publicly disseminated or fully developed. Recent changes to PTAB procedures, including the Director's personal decision on institution and the issuance of summary notices for denials, may also limit the public availability of detailed information for cases that are not instituted.

Therefore, at this time, specific attorneys representing Birchtech Corp. in this IPR cannot be identified from publicly available information.