Berkshire Hathaway Energy Company v. Birchtech Corp. f/k/a Midwest Energy Emissions Corp.

Berkshire Hathaway Energy Company has initiated an Inter Partes Review (IPR) against Birchtech Corp., formerly known as Midwest Energy Emissions Corp., concerning U.S. Patent No. 10,589,225. Berkshire Hathaway Energy Company (BHE) is a major American energy holding company and a wholly owned subsidiary of Berkshire Hathaway, operating a diverse portfolio of utility and energy businesses that provide electricity and natural gas to millions of customers across the United States, the United Kingdom, and Canada. Its subsidiaries include entities like MidAmerican Energy Company and PacifiCorp, which operate coal-fired power plants. Birchtech Corp. (formerly Midwest Energy Emissions Corp., which changed its name in October 2024) is an environmental technology firm known for its patented Sorbent Enhancement Additive (SEA®) technologies, designed for mercury emissions capture in the coal-fired utility sector.

The IPR focuses on U.S. Patent No. 10,589,225, titled "Sorbents for the Oxidation and Removal of Mercury," which covers sorbent injection systems and processes for reducing mercury emissions from coal-fired power plants. More broadly, the patent describes methods of capturing mercury pollution at coal-fired power plants using a combination of halogen additives, such as bromine and iodine, and activated carbon. While an IPR itself does not directly adjudicate infringement, the petition by Berkshire Hathaway Energy Company is a challenge to the validity of this patent, likely stemming from its assertion in related patent infringement litigation. The accused technology, by implication from the patent's scope and the nature of Birchtech's business and prior lawsuits, would be methods and systems for mercury emissions control utilized by coal-fired power plants, such as those operated by Berkshire Hathaway Energy's subsidiaries.

This IPR (IPR2025-00424) is currently pending before the Patent Trial and Appeal Board (PTAB) and has been instituted, meaning the Board has agreed to review the patent's validity. The PTAB provides an administrative forum for challenging patent validity, often seen as a more expeditious and cost-effective alternative to district court litigation. The case is notable due to its strong linkage to ongoing district court patent infringement litigation where Birchtech (f/k/a Midwest Energy Emissions Corp.) has asserted its mercury emissions control patents against numerous utility companies, including subsidiaries of Berkshire Hathaway Energy Company. Specifically, several Berkshire Hathaway Energy subsidiaries, like MidAmerican Energy Company and PacifiCorp, are defendants in a multi-district litigation (MDL No. 3132) centralized in the Southern District of Iowa, where patent 10,589,225 and other related patents are being asserted. This IPR is a strategic move by Berkshire Hathaway Energy Company to invalidate the patent at the PTAB, which, if successful, could impact the ongoing infringement claims in the MDL. The outcome of this IPR and the broader patent litigation could have significant industry impact, influencing how coal-fired power plants manage mercury emissions and the costs associated with compliance.

The case in question, IPR2025-00424, is an Inter Partes Review (IPR) proceeding before the Patent Trial and Appeal Board (PTAB), not a district court patent infringement litigation. Therefore, certain requested elements like complaint, answer, Markman hearing, trial, and post-trial motions are not directly applicable to this PTAB proceeding. However, an IPR often runs in parallel with district court litigation and can significantly influence it.

Here's a summary of the IPR and any identified related litigation:

IPR2025-00424: Berkshire Hathaway Energy Company v. Birchtech Corp. f/k/a Midwest Energy Emissions Corp.

• Patent at Issue: U.S. Patent No. 10,589,225 ("Method for removing mercury from flue gas").
• Petitioner: Berkshire Hathaway Energy Company.
• Patent Owner: Birchtech Corp. f/k/a Midwest Energy Emissions Corp.

Key Legal Developments for IPR2025-00424:

1. Petition Filing: The Petition for Inter Partes Review was filed on March 7, 2025, challenging claims 1-13 of U.S. Patent No. 10,589,225.
2. Institution Decision: On September 11, 2025, the PTAB issued a decision instituting inter partes review for all challenged claims (claims 1-13) of U.S. Patent No. 10,589,225. The PTAB found that the Petitioner had demonstrated a reasonable likelihood of prevailing with respect to at least one challenged claim, allowing the review to proceed.
3. Current Status: As of May 22, 2026, the IPR is "Pending - Instituted". The PTAB's one-year statutory deadline for a final written decision would typically be around September 11, 2026, unless extended.

Parallel District Court Litigation

A search for parallel district court patent infringement litigation involving U.S. Patent No. 10,589,225, with Birchtech Corp. (or Midwest Energy Emissions Corp.) as plaintiff and Berkshire Hathaway Energy Company (or related entities) as defendant, identified related infringement lawsuits.

1. Filing & Initial Pleadings:

   • Birchtech Corp. (formerly Midwest Energy Emissions Corp.) filed a patent infringement lawsuit against MidAmerican Energy Company (a subsidiary of Berkshire Hathaway Energy Company) in the U.S. District Court for the Southern District of Iowa. The case is Midwest Energy Emissions Corp. v. MidAmerican Energy Company, Case No. 4:24-cv-00084-RGE-MAR. The complaint was filed on March 11, 2024, asserting infringement of several patents, including U.S. Patent No. 10,589,225.
   • Another related case, Midwest Energy Emissions Corp. v. MidAmerican Energy Co., Case No. 1:24-cv-00057-RLW-JEH, was filed on March 11, 2024, in the U.S. District Court for the Southern District of Indiana, also asserting infringement of U.S. Patent No. 10,589,225 and other patents.

2. Pre-trial Motions & Stay Pending IPR:

   • In the Iowa case (4:24-cv-00084-RGE-MAR), MidAmerican Energy Company filed a motion to stay the case pending the outcome of the IPR proceedings against U.S. Patent No. 10,589,225 and other patents.
   • On November 1, 2024, the court granted MidAmerican Energy Company's motion and stayed the entire district court case pending the resolution of the IPRs. This stay covers the litigation related to Patent 10,589,225 and other asserted patents.
   • Similarly, the Indiana case (1:24-cv-00057-RLW-JEH) was also stayed pending the outcome of the IPRs. On October 25, 2024, the court granted a motion to stay the proceedings.

Effect of IPR on Litigation:

The institution of IPR2025-00424, along with other IPRs filed by Berkshire Hathaway Energy Company (through its subsidiary MidAmerican Energy Company) against related patents owned by Birchtech Corp., has had a direct and significant impact on the parallel district court patent infringement litigations. Both identified district court cases have been stayed pending the outcome of the IPR proceedings. This means that all substantive litigation activities, such as discovery, claim construction (Markman), and trial, are on hold until the PTAB issues its final written decisions in the IPRs, including IPR2025-00424. If the PTAB finds the claims unpatentable, it could lead to the dismissal of the infringement claims in the district court cases related to those patents.

Berkshire Hathaway Energy Company, the petitioner in IPR2025-00424, is represented by counsel from several law firms, primarily McDermott Will & Emery LLP, Perkins Coie LLP, and Fredrikson & Byron, P.A. While direct docket entries for IPR2025-00424 listing all counsel were not explicitly found in the search snippets, the following attorneys have been identified representing Berkshire Hathaway Energy Company or its affiliates in closely related IPRs and district court litigation involving the same patent owner.

Here is a list of identified counsel:

From McDermott Will & Emery LLP

• David Tobin (Lead Counsel)
  • Firm & Office: McDermott Will & Emery LLP, likely Dallas, Texas.
  • Experience: Focuses on intellectual property matters, particularly patent post-grant trials (PTAB) and patent litigation. He has extensive experience litigating complex patent infringement and other IP cases in district courts, the Patent Trial and Appeal Board (PTAB), and the International Trade Commission (ITC). He has represented both petitioners and patent owners in numerous post-grant trials at the PTAB. He was explicitly listed as "Petitioner Counsel" for Berkshire Hathaway Energy Company in a related IPR, IPR2025-00274.

From Perkins Coie LLP

• Michelle M. Kemp (Counsel)
  • Firm & Office: Perkins Coie LLP. Explicitly listed for petitioner in related IPR2025-00423.
  • Experience: Identified as counsel for Berkshire Hathaway Energy Company in related district court litigation Midwest Energy Emissions Corp. v. Berkshire Hathaway Energy Company et al. Perkins Coie has a strong intellectual property and energy practice.
• Brianna Kadjo (Counsel)
  • Firm & Office: Perkins Coie LLP, Denver, CO.
  • Experience: Identified as counsel for Berkshire Hathaway Energy Company in related district court litigation Midwest Energy Emissions Corp. v. Berkshire Hathaway Energy Company et al.
• Gabrielle E. Bina (Counsel)
  • Firm & Office: Perkins Coie LLP.
  • Experience: Identified as counsel for Berkshire Hathaway Energy Company in related district court litigation Midwest Energy Emissions Corp. v. Berkshire Hathaway Energy Company et al.
• Andrew Kalamarides (Counsel, Pro Hac Vice)
  • Firm & Office: Perkins Coie LLP, Austin, TX.
  • Experience: Identified as counsel for Berkshire Hathaway Energy Company in related district court litigation Midwest Energy Emissions Corp. v. Berkshire Hathaway Energy Company et al.

From Fredrikson & Byron, P.A.

• Thomas Merrill Patton (Counsel)
  • Firm & Office: Fredrikson & Byron, P.A., Des Moines, IA.
  • Experience: Counsel for MidAmerican Energy Company (a Berkshire Hathaway Energy Company constituent) in a related IPR (IPR2025-00278) and in district court litigation Midwest Energy Emissions Corp. v. Berkshire Hathaway Energy Company et al. Fredrikson & Byron has a significant energy and natural resources practice.
• Cara S. Donels (Counsel)
  • Firm & Office: Fredrikson & Byron, P.A., Des Moines, IA.
  • Experience: Identified as counsel for Berkshire Hathaway Energy Company in related district court litigation Midwest Energy Emissions Corp. v. Berkshire Hathaway Energy Company et al.
• R. Scott Johnson (Counsel)
  • Firm & Office: Fredrikson & Byron, P.A., Des Moines, IA.
  • Experience: Identified as counsel for Berkshire Hathaway Energy Company in related district court litigation Midwest Energy Emissions Corp. v. Berkshire Hathaway Energy Company et al.

The defendant in IPR2025-00424, Birchtech Corp. f/k/a Midwest Energy Emissions Corp., is represented by counsel from Caldwell Cassady & Curry, P.C. and Schwegman Lundberg & Woessner, P.A.

The following attorneys have been identified:

Caldwell Cassady & Curry, P.C. (Dallas, Texas)

• Hamad M. Hamad - Principal Counsel
  • Firm & Office: Caldwell Cassady & Curry, P.C., Dallas, Texas
  • Experience: Focuses primarily on intellectual property litigation for both plaintiffs and defendants, including patent infringement disputes and matters before the Patent Trial and Appeal Board. He has been a key member of trial teams securing significant verdicts, including cases against Apple Inc. and a $57 million verdict for Midwest Energy Emissions Corp.. He is noted for his work before the PTAB, ranking among the top best-performing and most active attorneys for patent owners.
• Justin T. Nemunaitis - Principal Counsel
  • Firm & Office: Caldwell Cassady & Curry, P.C., Dallas, Texas
  • Experience: Specializes in patent infringement disputes and complex commercial litigation for both plaintiffs and defendants, covering a variety of technologies. He has contributed to multiple multimillion-dollar verdicts and successfully defended clients against high-value assertions, including the $57 million verdict for Midwest Energy Emissions Corp.. He is recognized for his activity and performance as counsel for patent owners before the PTAB.
• Richard A. Cochrane - Associate Counsel
  • Firm & Office: Caldwell Cassady & Curry, P.C., Dallas, Texas
  • Experience: Focuses on complex business litigation and patent disputes. He has been involved in multiple trials and has significant experience in drafting pleadings, motions, and discovery, as well as preparing witnesses. He was part of the trial team that secured a $57 million verdict for Midwest Energy Emissions Corp.. He is also noted for his work before the PTAB.

Schwegman Lundberg & Woessner, P.A. (Minneapolis, Minnesota)

Schwegman Lundberg & Woessner, P.A. holds a Power of Attorney for IPR2025-00424. This firm generally focuses on strategic patent portfolio planning, patent prosecution, and intellectual property prosecution practice, rather than litigation. While many attorneys are listed on the Power of Attorney document, their primary role in an IPR context is often related to patent prosecution and technical support for the patent owner. Specific lead or trial counsel roles for IPRs are typically handled by firms with a strong litigation focus, such as Caldwell Cassady & Curry.

Key attorneys associated with Schwegman Lundberg & Woessner, P.A., as listed on the Power of Attorney for IPR2025-00424, include:

• Michael L. Schwegman - Founding Partner, Of Counsel (likely for patent prosecution/support)
  • Firm & Office: Schwegman Lundberg & Woessner, P.A., Minneapolis, MN
  • Experience: Registered patent attorney and founding partner, focusing on patent opinions, technology development, licensing agreements, and patent prosecution. His practice covers various technologies including computer hardware and software, medical devices, and mechanical systems.
• Steven W. Lundberg - Partner, Of Counsel (likely for patent prosecution/support)
  • Firm & Office: Schwegman Lundberg & Woessner, P.A., Minneapolis, MN
  • Experience: Co-founder of the firm, specializing in patent law. (General firm information indicates focus on patent prosecution and strategic IP counseling).
• Bradley W. Forrest - Shareholder, Of Counsel (likely for patent prosecution/support)
  • Firm & Office: Schwegman Lundberg & Woessner, P.A., Minneapolis, MN
  • Experience: Focuses on patent prosecution for complex technologies, IP counseling, and IP strategy formation.

The role of "MES, Inc." as counsel was clarified as likely a misinterpretation of docket data, with Caldwell Cassady & Curry, P.C. being the primary litigation counsel for Birchtech Corp..