Midwest Energy Emissions Corp. et al. v. Tucson Electric Power Co. et al.

This patent infringement litigation, Midwest Energy Emissions Corp. et al. v. Tucson Electric Power Co. et al., involves Midwest Energy Emissions Corp. (now known as Birchtech Corp.), an operating clean technology company specializing in air and water treatment solutions, asserting its intellectual property against multiple electric utility and energy sector defendants. The plaintiff, Birchtech Corp., develops and commercializes patented Sorbent Enhancement Additive (SEA®) technologies primarily for mercury emissions capture in coal-fired power plants, and also has a growing water purification division. The defendants include major power providers such as Tucson Electric Power Co., an electric utility serving southern Arizona; Salt River Project Agricultural Improvement and Power District, a power and water utility for the Phoenix metropolitan area; and Tri-State Generation and Transmission Association, Inc., a cooperative power supplier for the rural West. Other defendants, San Carlos Resources, Inc., Springerville Unit 3 Holding LLC, and Springerville Unit 3 Partnership LP, are likely involved in refined coal operations or power generation activities.

The core of the dispute centers on the defendants' alleged unlicensed use of Birchtech's mercury emissions reduction technologies, specifically targeting methods for capturing mercury pollution at coal-fired power plants by utilizing halogen additives (such as bromine and iodine) and activated carbon. The primary patent at issue in this case is US Patent 10933370, which relates to "operational practices for coal plant exhaust systems" designed for mercury and particulate emission reduction. This lawsuit, originally filed in the Arizona District Court (3:24-cv-08145) on July 17, 2024, by Midwest Energy Emissions Corp. (which announced its rebranding to Birchtech Corp. effective October 17, 2024), was one of three separate lawsuits filed on July 30, 2024, against a total of 14 defendants. These cases were subsequently centralized on December 12, 2024, into Multidistrict Litigation (MDL) No. 3132 in the Southern District of Iowa, presided over by Judge Stephen H. Locher. The centralization aims to streamline discovery and prevent inconsistent rulings on common factual questions, particularly regarding claim construction and patent validity across a widespread patent enforcement campaign. The Arizona case was initially assigned to Judge Diane J. Humetewa before being transferred to the MDL.

This litigation is notable as it is part of a broader, aggressive patent enforcement campaign by Birchtech Corp., an operating company that actively seeks to license its proprietary mercury capture technologies to the coal-fired utility sector. The company has a history of successful patent litigation, including a prior $78 million judgment in a Delaware case that concluded in December 2025, validating its intellectual property in the clean air technology market. The asserted patent, US 10933370, has also faced challenges at the Patent Trial and Appeal Board (PTAB), including an Inter Partes Review (IPR2025-01324) filed by Union Electric Company and a Director Review decision regarding the institution of multiple petitions by PacifiCorp and MidAmerican Energy Company. These PTAB challenges underscore the significant efforts by defendants to invalidate Birchtech's patents.

Midwest Energy Emissions Corp. et al. v. Tucson Electric Power Co. et al. - Key Legal Developments

Case Number: 3:24-cv-08145
Court: Initially Arizona District Court, now centralized in Southern District of Iowa (MDL No. 3132)
Patents at Issue: U.S. Patent 10,933,370

This patent infringement lawsuit, originally filed in the District of Arizona, has been centralized as part of a multidistrict litigation (MDL) in the Southern District of Iowa.

Chronological Legal Developments:

• 2024-07-17: Complaint Filed. Midwest Energy Emissions Corp. (now Birchtech Corp.) filed its complaint in the Arizona District Court against multiple defendants, including Tucson Electric Power Co., alleging infringement of U.S. Patent 10,933,370.
• 2024-09-05: Stipulation for Extension of Time to Answer. Defendants, including Salt River Project Agricultural Improvement and Power District, Tucson Electric Power Company, and San Carlos Resources, Inc., stipulated to an extension of time to respond to the complaint, pushing the deadline to October 15, 2024. This was a second request, indicating earlier extensions were also granted.
• 2024-10-17: Plaintiff Name Change. Midwest Energy Emissions Corp. formally changed its corporate name to Birchtech Corp.
• 2024-12-12: Centralization into MDL No. 3132. The U.S. Judicial Panel on Multidistrict Litigation (JPML) issued a transfer order centralizing this action, along with others from the Eastern District of Missouri and the Southern District of Iowa, into MDL No. 3132 in the Southern District of Iowa. The MDL is titled "In re: Midwest Energy Emissions Corp. Patent Litigation" and the case was assigned to Judge Stephen H. Locher. The JPML found that the cases involved common questions of fact regarding allegations of infringing patents related to capturing mercury pollution at coal-fired power plants. Five of the six patents asserted across the various complaints were common to all three initial actions.
• 2024-12-17: Transfer Order Docketed in Arizona. The transfer order from the JPML was docketed in the Arizona District Court, effectively transferring case 3:24-cv-08145 to MDL No. 3132 in the Southern District of Iowa.
• 2025-01-30 to 2025-01-31: Cases Transferred into MDL. Various related cases, including those originally filed in the District of Wyoming and Western District of Wisconsin, were formally transferred into MDL No. 3132 in the Southern District of Iowa, with future pleadings to be filed in the lead MDL case (4:24-md-3132).
• 2025-03-26: USPTO Memorandum on PTAB Workload Management. The USPTO issued an interim process for PTAB workload management, relevant to how multiple petitions for IPR might be handled.
• 2025-09-08: IPR Institution for a Related Patent (10,343,114). While not directly for patent 10,933,370, an Inter Partes Review (IPR) was instituted for claims 1-30 of U.S. Patent 10,343,114 B2, a related patent concerning mercury emissions control. This IPR (IPR2025-00278) was initiated by several entities, including Alliant Energy Corporation, who are also involved in the broader patent litigation. The PTAB determined there was a reasonable likelihood that the petitioner would prevail on at least one claim.

Present Posture:

The case is currently centralized within MDL No. 3132 in the Southern District of Iowa under Judge Stephen H. Locher for coordinated or consolidated pretrial proceedings. This centralization aims to streamline discovery, prevent inconsistent pretrial rulings, especially concerning claim construction and patent validity, and conserve resources. As of the current date (2026-05-22), there have been no publicly reported outcomes for substantive pre-trial motions, claim construction, trial, or final judgment specifically for the 3:24-cv-08145 case. The litigation is ongoing within the MDL framework. While IPRs have been instituted for related patents, a specific IPR for U.S. Patent 10,933,370 has not been identified in the provided search results.I have completed the first step of searching for the case docket and transfer information. The results indicate the filing date, the centralization into MDL No. 3132 on December 12, 2024, and the transfer to the Southern District of Iowa under Judge Stephen H. Locher. It also mentions extensions of time to respond to the complaint. A key point is the plaintiff's name change to Birchtech Corp. as of October 17, 2024.

The previous search found an IPR for US Patent 10,668,430 (IPR2025-00423) and US Patent 10,343,114 B2 (IPR2025-00278), both related to emissions control patents. However, the asserted patent in this specific case is 10933370, and I need to specifically look for IPRs related to this patent.

I still need to:

1. Confirm the exact filing date of the complaint (the initial search showed both July 17 and July 30, 2024).
2. Find details about answers and counterclaims filed.
3. Search for any substantive pre-trial motions (motions to dismiss, stay pending IPR, summary judgment) and their outcomes in both the original court and the MDL.
4. Search for claim construction (Markman) outcomes in the MDL.
5. Look for discovery milestones with strategic significance within the MDL.
6. Determine if the case reached trial, verdict, or post-trial motions.
7. Identify the final disposition or present posture within the MDL.
8. Crucially, conduct a targeted search for PTAB IPR/PGR proceedings specifically on US Patent 10933370.

I will refine my next steps to focus on these outstanding points.

Midwest Energy Emissions Corp. et al. v. Tucson Electric Power Co. et al. - Key Legal Developments

Case Number: 3:24-cv-08145
Court: Initially Arizona District Court, now centralized in Southern District of Iowa (MDL No. 3132)
Patents at Issue: U.S. Patent 10,933,370

This patent infringement lawsuit, originally filed in the District of Arizona, has been centralized as part of a multidistrict litigation (MDL) in the Southern District of Iowa. The plaintiff, Midwest Energy Emissions Corp., formally changed its name to Birchtech Corp. effective October 17, 2024.

Chronological Legal Developments:

• 2024-07-17: Complaint Filed. Midwest Energy Emissions Corp. filed its complaint in the Arizona District Court against multiple defendants, including Tucson Electric Power Co., alleging infringement of U.S. Patent 10,933,370.
• 2024-09-05: Stipulation for Extension of Time to Answer. Defendants, including Salt River Project Agricultural Improvement and Power District, Tucson Electric Power Company, and San Carlos Resources, Inc., stipulated to an extension of time to respond to the complaint, with the deadline extended to October 15, 2024. This was noted as a second request, indicating prior extensions.
• 2024-10-17: Plaintiff Name Change. Midwest Energy Emissions Corp. formally changed its corporate name to Birchtech Corp.
• 2024-12-12: Centralization into MDL No. 3132. The U.S. Judicial Panel on Multidistrict Litigation (JPML) issued a transfer order centralizing this action, along with others from the Eastern District of Missouri and the Southern District of Iowa, into MDL No. 3132 in the Southern District of Iowa. The MDL is titled "In re: Midwest Energy Emissions Corp. Patent Litigation" and the case was assigned to Judge Stephen H. Locher for coordinated or consolidated pretrial proceedings. The JPML noted that these actions share factual questions arising from allegations that defendants infringed patents describing a method of capturing mercury pollution at coal-fired power plants. Five of the six patents identified in the complaints were asserted in all three initial actions.
• 2024-12-17: Transfer Order Docketed in Arizona. The transfer order from the JPML was docketed in the Arizona District Court, effectively transferring case 3:24-cv-08145 to MDL No. 3132 in the Southern District of Iowa.
• 2025-01-30 to 2025-01-31: Related Cases Transferred into MDL. Various related cases, including those originally filed in the District of Wyoming and Western District of Wisconsin, were formally transferred into MDL No. 3132 in the Southern District of Iowa, with future pleadings to be filed in the lead MDL case (4:24-md-3132).
• 2025-03-26: USPTO Memorandum on PTAB Workload Management. The USPTO issued an interim process for PTAB workload management, which outlines procedures for addressing discretionary issues, including those related to multiple IPR petitions.
• 2025-09-08: IPR Institution for Related Patent 10,343,114 B2 (IPR2025-00278). An Inter Partes Review was instituted for claims 1-30 of U.S. Patent 10,343,114 B2, a related patent also concerning emissions control technology. The PTAB determined that the petitioner, including entities also involved in the broader patent litigation, had established a reasonable likelihood of prevailing on at least one challenged claim. Another concurrent petition (IPR2025-00274) against the same patent was also noted.
• 2025-09-08: IPR Institution for Related Patent 10,668,430 B2 (IPR2025-00423). An Inter Partes Review was instituted for claims 1-4 and 6-29 of U.S. Patent 10,668,430 B2, another related patent. The Acting Director determined that discretionary denial of institution was not appropriate, and the Board proceeded to institute review of all challenged claims.

Present Posture:

The case is currently centralized within MDL No. 3132 in the Southern District of Iowa under Judge Stephen H. Locher for coordinated or consolidated pretrial proceedings. As of the current date (2026-05-22), specific details regarding answers, counterclaims, substantive pre-trial motions (beyond the initial extension to respond), claim construction (Markman) outcomes, or significant discovery milestones for this specific case within the MDL are not publicly detailed in the provided search results. The centralization aims to streamline these processes across the various related cases.

Regarding parallel PTAB proceedings, while IPRs have been instituted for related patents (10,343,114 B2 and 10,668,430 B2), a specific IPR or PGR proceeding on the directly asserted patent, U.S. Patent 10,933,370, has not been identified in the available public information. The MDL will likely address claim construction for the asserted patents, including 10,933,370, as a consolidated matter.

Based on the available information, the primary counsel of record representing the plaintiff(s), Midwest Energy Emissions Corp. and Birchtech Corp., in this patent infringement case (now centralized as part of MDL No. 3132 in the Southern District of Iowa) is Caldwell Cassady & Curry.

The following attorneys from Caldwell Cassady & Curry have been identified as involved in the plaintiff's patent litigation efforts, and are highly likely to be counsel of record in this case and the overarching MDL:

• Bradley W. "Brad" Caldwell

  • Role: Lead Counsel (inferred based on consistent role as lead trial counsel in related high-stakes patent infringement cases for Midwest Energy/Birchtech).
  • Firm: Caldwell Cassady & Curry, Dallas, Texas
  • Note: Nationally recognized trial lawyer specializing in patent infringement, with over $3 billion in verdicts, including multiple nine-figure verdicts against major technology companies like Apple and Samsung. He served as lead trial counsel for Midwest Energy Emissions Corp. in a Delaware patent infringement case that resulted in a $57 million verdict.

• Justin T. Nemunaitis

  • Role: Lead Counsel (confirmed by filings in MDL No. 3132 on behalf of plaintiff).
  • Firm: Caldwell Cassady & Curry, Dallas, Texas
  • Note: A principal focusing on patent infringement disputes and complex commercial litigation, who has represented clients in a wide variety of technologies and helped secure large verdicts. He filed motions and corporate disclosure statements on behalf of the plaintiff in the MDL.

• Daniel R. Pearson

  • Role: Counsel (inferred based on consistent involvement in plaintiff's patent litigation team).
  • Firm: Caldwell Cassady & Curry, Dallas, Texas
  • Note: Focuses on complex commercial litigation and patent infringement disputes, with experience in all stages of litigation and has helped secure multiple multimillion-dollar verdicts.

• Adrienne Dellinger

  • Role: Counsel (inferred based on consistent involvement in plaintiff's patent litigation team).
  • Firm: Caldwell Cassady & Curry, Dallas, Texas
  • Note: An accomplished patent litigator with expertise in intellectual property law across various technical disciplines, and a former judicial clerk for Hon. Rodney Gilstrap in the Eastern District of Texas.

• Aisha Mahmood Haley

  • Role: Counsel (inferred based on consistent involvement in plaintiff's patent litigation team, and specifically mentioned as playing a key role in the $57 million Midwest Energy verdict).
  • Firm: Caldwell Cassady & Curry, Dallas, Texas
  • Note: A principal focusing on complex business litigation and patent disputes, with extensive experience in all phases of high-value and complex litigation, and former law clerk for the U.S. Court of Appeals for the Federal Circuit.

• Richard Cochrane

  • Role: Counsel (inferred based on consistent involvement in plaintiff's patent litigation team).
  • Firm: Caldwell Cassady & Curry, Dallas, Texas
  • Note: An associate focusing on complex business litigation and patent disputes, with experience drafting pleadings, motions, and discovery, and assisting in multiple trials.

While these attorneys are clearly identified with the plaintiff's patent enforcement efforts, and Justin Nemunaitis has officially appeared in the MDL, specific individual docket entries for each listed attorney explicitly detailing their exact role (e.g., "local counsel" for Arizona district court before centralization, or specific "lead counsel" designation within the MDL) are not directly available without PACER access to the underlying Arizona case or more detailed MDL docket entries. Given the centralization, the Caldwell Cassady & Curry team acts as the lead counsel for the plaintiff in the consolidated proceedings. There is no explicit mention of separate local counsel for the Arizona District Court case after its transfer to the MDL.

This report details the counsel of record representing the defendants in Midwest Energy Emissions Corp. et al. v. Tucson Electric Power Co. et al. (Case number: 3:24-cv-08145, Arizona District Court). The case was centralized as part of MDL No. 3132 in the Southern District of Iowa on December 12, 2024.

Counsel for Defendants Tucson Electric Power Co. and San Carlos Resources, Inc.

• Michael J. Curley
  • Role: Counsel
  • Firm: Quarles & Brady LLP
  • Office Location: Tucson, Arizona
  • Notable Experience: Mr. Curley's practice includes commercial litigation. He has represented Tucson Electric Power Company and San Carlos Resources, Inc. in this patent infringement case.

Counsel for Defendant Salt River Project Agricultural Improvement and Power District

• Eric D. Gere
  • Role: Counsel
  • Firm: Spencer Fane LLP
  • Office Location: Phoenix, Arizona
  • Notable Experience: Mr. Gere represents Salt River Project Agricultural Improvement and Power District in this action.
• John V. Picone III
  • Role: Counsel (Pro Hac Vice to be filed)
  • Firm: Spencer Fane LLP
  • Office Location: San Jose, California
  • Notable Experience: Mr. Picone is listed as counsel for Salt River Project Agricultural Improvement and Power District, with a pro hac vice appearance pending.
• Gene Cherng
  • Role: Counsel (Pro Hac Vice to be filed)
  • Firm: Spencer Fane LLP
  • Office Location: San Jose, California
  • Notable Experience: Mr. Cherng is listed as counsel for Salt River Project Agricultural Improvement and Power District, with a pro hac vice appearance pending.

Counsel for Defendants Tri-State Generation and Transmission Association Inc., Springerville Unit 3 Holding LLC, and Springerville Unit 3 Partnership LP

• Joseph C. Daniels
  • Role: Counsel
  • Firm: Michael Best & Friedrich LLP
  • Office Location: Denver, Colorado
  • Notable Experience: Mr. Daniels represents Tri-State Generation and Transmission Association Inc., Springerville Unit 3 Holding LLC, and Springerville Unit 3 Partnership LP in this litigation.