Assignment history

Inventors

• Edwin S. Olson: Likely affiliated with Energy and Environmental Research Center Foundation (EERC) at the time of invention, given assignments to EERC. EERC was involved in federally sponsored research related to this patent.
• Michael J. Holmes: Likely affiliated with Energy and Environmental Research Center Foundation (EERC) at the time of invention, given assignments to EERC. EERC was involved in federally sponsored research related to this patent.
• John H. Pavlish: Likely affiliated with Energy and Environmental Research Center Foundation (EERC) at the time of invention, given assignments to EERC. EERC was involved in federally sponsored research related to this patent.

The patent itself notes that it "was made with United States Government support under Grant Numbers R 827649-01 and CR 830929-01 awarded by the United States Environmental Protection Agency and under Contract Number DE-FC26-98FT40320 awarded by the United States Department of Energy". This context, coupled with the assignments from the inventors to the Energy and Environmental Research Center Foundation, strongly suggests their employment or affiliation with EERC around the priority date of August 30, 2004, and subsequently, the rights flowed to Midwest Energy Emissions Corp.

Original assignee

The entity named as "Original Assignee" on Google Patents is Midwest Energy Emissions Corp.

Midwest Energy Emissions Corp. (MEEC) is a publicly traded company (though not explicitly stated in the patent text, their litigation profile and nature of business imply this). Their primary line of business, as described in the patent, involves providing methods and materials for the removal of mercury and other pollutants from gas streams, particularly flue gas from coal combustion or gasification systems, utilizing sorbent technologies. They ship products embodying the claims, specifically the halogen/halide promoted activated carbon sorbents and related mercury control systems.

As of the current date (May 17, 2026), Midwest Energy Emissions Corp changed its name to Birchtech Corp. on November 7, 2024, as indicated by a "Change of Name" legal event. Therefore, the original assignee, under its new name, is still operating.

Assignment timeline

The following assignment records are derived from the Google Patents legal events, which reflect underlying USPTO records. Specific reel/frame and correspondent information is not explicitly provided in the Google Patents extract; therefore, these fields are marked as "Not recorded in source."

• 2019-09-23 (executed) / recorded 2019-09-23 (approx.) — Reel Not recorded in source
  • Conveyance: Assignment
  • Assignor: PAVLISH, JOHN H.
  • Assignee: ENERGY AND ENVIRONMENTAL RESEARCH CENTER FOUNDATION
  • Correspondent: Not recorded in source
  • Context: Inventor assignment
• 2019-09-23 (executed) / recorded 2019-09-23 (approx.) — Reel Not recorded in source
  • Conveyance: Assignment
  • Assignor: HOLMES, MICHAEL J.
  • Assignee: ENERGY AND ENVIRONMENTAL RESEARCH CENTER FOUNDATION
  • Correspondent: Not recorded in source
  • Context: Inventor assignment
• 2019-09-23 (executed) / recorded 2019-09-23 (approx.) — Reel Not recorded in source
  • Conveyance: Assignment
  • Assignor: OLSON, EDWIN S.
  • Assignee: ENERGY AND ENVIRONMENTAL RESEARCH CENTER FOUNDATION
  • Correspondent: Not recorded in source
  • Context: Inventor assignment
• 2019-09-23 (executed) / recorded 2019-09-23 (approx.) — Reel Not recorded in source
  • Conveyance: Assignment
  • Assignor: ENERGY AND ENVIRONMENTAL RESEARCH CENTER FOUNDATION
  • Assignee: MIDWEST ENERGY EMISSIONS CORP.
  • Correspondent: Not recorded in source
  • Context: Transfer from a research foundation to a commercial entity.
• 2020-03-11 (executed) / recorded 2020-03-11 (approx.) — Reel Not recorded in source
  • Conveyance: Corrective Assignment
  • Assignor: ENERGY AND ENVIRONMENTAL RESEARCH CENTER FOUNDATION
  • Assignee: MIDWEST ENERGY EMISSIONS CORP.
  • Correspondent: Not recorded in source
  • Context: Corrective assignment to update assignee address.
• 2024-11-07 (executed) / recorded 2024-11-07 (approx.) — Reel Not recorded in source
  • Conveyance: Change of Name
  • Assignor: MIDWEST ENERGY EMISSIONS CORP.
  • Assignee: BIRCHTECH CORP.
  • Correspondent: Not recorded in source
  • Context: Corporate name change from Midwest Energy Emissions Corp to Birchtech Corp.

Timeline diagram

timeline
    title Ownership of US 10596517
    2004 : Priority date
    2018 : Filed by Midwest Energy Emissions Corp
    2019 : Inventors assigned to EERC
         : EERC assigned to Midwest Energy
    2020 : Corrective assignment to Midwest Energy
         : Patent issued
    2024 : Midwest Energy changes name to Birchtech

NPE / troll-pattern signals

1. Shell-entity transfer — Not present. The transfers involve named operating companies or research foundations. The most recent change is a corporate name change, not a transfer to a shell entity.
2. Known asserter in the chain — Not present. Midwest Energy Emissions Corp (now Birchtech Corp) is an operating company in the environmental technology sector. There is no indication of transfer to a known NPE.
3. Repeat correspondent across the chain — Unclear. Correspondent information (name, firm, address) is not provided in the source text.
4. Cascading transfers — Not present. There were several assignments on the same day in 2019 (inventors to EERC, then EERC to Midwest Energy Emissions Corp), which is common for perfecting title after initial invention disclosure and application filing. The next recorded event is a corrective assignment, followed by a name change years later. This does not suggest rapid, chained transfers to multiple shell entities.
5. Pre-litigation transfer — Unclear. The patent family is involved in extensive litigation, with cases filed in various district courts and the CAFC. However, the initial assignments from inventors to Midwest Energy Emissions Corp via EERC occurred in 2019, and the patent issued in 2020. The earliest litigation case mentioned without a specific filing date is for Delaware District Court 1:19-cv-01334. If this case was filed prior to the 2019 assignments being recorded, it could indicate pre-litigation transfer. However, without precise litigation filing dates and corresponding assignment recording dates, it's unclear if the transfers were specifically timed to precede assertion for this patent. The earliest specific litigation date provided (Unified Patents data) is 2024-03-19 (for Missouri Eastern District Court 4:24-cv-00980). The latest assignment is the name change in November 2024. Therefore, it does not appear that the Birchtech name change was a pre-litigation transfer.
6. Bankruptcy fire-sale — Not present. There is no indication of the original assignee, Midwest Energy Emissions Corp, undergoing bankruptcy proceedings and selling off its patent assets.
7. Privateering — Not present. The current owner, Birchtech Corp (formerly Midwest Energy Emissions Corp), is an operating company asserting its own intellectual property, not transferring it to an NPE to assert on its behalf.
8. Defensive aggregator (anti-NPE) — Not present. The chain does not terminate at a defensive aggregator like RPX, AST, LOT Network, Unified Patents, or Open Invention Network.

Verdict

Operating-company assertion

The chain shows an initial transfer from inventors to a research foundation (EERC), then to Midwest Energy Emissions Corp (an operating company) in 2019, which is a standard commercialization path for university/research-originated IP. Subsequently, Midwest Energy Emissions Corp changed its name to Birchtech Corp in 2024, maintaining ownership. The extensive litigation activity is being conducted by the operating company (Birchtech Corp) to assert its intellectual property, which is consistent with an operating company protecting its market and technology.

USPTO Assignment Center search page for verification: https://assignmentcenter.uspto.gov/