Assignment history

Inventors

• Edwin S. Olson: Midwest Energy Emissions Corp. (implied by original assignee)
• Michael J. Holmes: Midwest Energy Emissions Corp. (implied by original assignee)
• John H. Pavlish: Midwest Energy Emissions Corp. (implied by original assignee)

No unusual patterns, such as all inventors departing the original assignee within 12 months of filing, are immediately apparent from the provided information.

Original assignee

The original assignee, as listed on the issued patent, is Midwest Energy Emissions Corp.. Their primary line of business, based on the patent's subject matter, is likely related to environmental technologies, specifically mercury removal from gas streams, suggesting they shipped products or provided services embodying the claims. As of November 7, 2024, Midwest Energy Emissions Corp. reassigned the patent to Birchtech Corp..

Assignment timeline

• 2019-09-23 (executed) / recorded 2019-09-23

  • Conveyance: Assignment of Assignors Interest
  • Assignor: PAVLISH, JOHN H.
  • Assignee: ENERGY AND ENVIRONMENTAL RESEARCH CENTER FOUNDATION
  • Correspondent: Not specified in Google Patents, but likely the attorney for the Energy and Environmental Research Center Foundation.
  • Context: Transfer from individual inventor to research institution.

• 2019-09-23 (executed) / recorded 2019-09-23

  • Conveyance: Assignment of Assignors Interest
  • Assignor: HOLMES, MICHAEL J.
  • Assignee: ENERGY AND ENVIRONMENTAL RESEARCH CENTER FOUNDATION
  • Correspondent: Not specified in Google Patents, but likely the attorney for the Energy and Environmental Research Center Foundation.
  • Context: Transfer from individual inventor to research institution.

• 2019-09-23 (executed) / recorded 2019-09-23

  • Conveyance: Assignment of Assignors Interest
  • Assignor: OLSON, EDWIN S.
  • Assignee: ENERGY AND ENVIRONMENTAL RESEARCH CENTER FOUNDATION
  • Correspondent: Not specified in Google Patents, but likely the attorney for the Energy and Environmental Research Center Foundation.
  • Context: Transfer from individual inventor to research institution.

• 2019-09-23 (executed) / recorded 2019-09-23

  • Conveyance: Assignment of Assignors Interest
  • Assignor: ENERGY AND ENVIRONMENTAL RESEARCH CENTER FOUNDATION
  • Assignee: MIDWEST ENERGY EMISSIONS CORP.
  • Correspondent: Not specified in Google Patents, but likely the attorney for Midwest Energy Emissions Corp.
  • Context: Transfer from research institution to original assignee.

• 2024-11-07 (executed) / recorded 2024-11-07

  • Conveyance: Change of Name
  • Assignor: MIDWEST ENERGY EMISSIONS CORP.
  • Assignee: BIRCHTECH CORP.
  • Correspondent: Not specified in Google Patents, but likely the attorney for Birchtech Corp.
  • Context: Corporate name change from Midwest Energy Emissions Corp. to Birchtech Corp.

Timeline diagram

timeline
    title Ownership of US 10933370
    2018 : Filed by Midwest Energy Emissions Corp
    2019 : Inventors assigned to EERC Foundation
         : EERC Foundation assigned to Midwest Energy Emissions Corp
    2021 : Issued
    2024 : Midwest Energy Emissions Corp changed name to Birchtech Corp

NPE / troll-pattern signals

1. Shell-entity transfer — Unclear. While Birchtech Corp. could potentially be a licensing entity, there is no explicit evidence in the provided data (e.g., registered-agent address, explicit statement of no products) to confirm it is a shell entity. The conveyance type is "Change of Name", suggesting a rebranding or corporate restructuring of an existing operating company rather than a transfer to a new, separate shell.

2. Known asserter in the chain — Not present. None of the assignees (Midwest Energy Emissions Corp., Energy and Environmental Research Center Foundation, Birchtech Corp.) are listed as known NPEs in common directories based on the provided information.

3. Repeat correspondent across the chain — Unclear. The provided Google Patents data does not include correspondent information for the assignment records, making it impossible to assess this signal.

4. Cascading transfers — Not present. There are two transfers in 2019, from individual inventors to a foundation, and then from the foundation to Midwest Energy Emissions Corp., both occurring on the same day. This suggests an internal organizational or IP management process rather than a rapid, speculative transfer through multiple LLCs.

5. Pre-litigation transfer — Unclear. The earliest listed litigation (IPR2025-00688) was filed on March 24, 2025. The most recent assignment (change of name) occurred on November 7, 2024, which is within six months of the IPR filing. However, an IPR is a patent validity challenge, not an infringement suit, and the "Change of Name" conveyance type does not suggest a transfer specifically to enable litigation.

6. Bankruptcy fire-sale — Not present. No evidence of bankruptcy proceedings for Midwest Energy Emissions Corp. or Birchtech Corp. is provided.

7. Privateering — Not present. No information suggests an operating company transferred the patent to an NPE for assertion against competitors.

8. Defensive aggregator (anti-NPE) — Not present. The chain does not terminate at a known defensive aggregator.

Verdict

Insufficient data. While there is litigation activity related to the patent (multiple district court cases and PTAB challenges), the provided assignment records primarily show a transfer from inventors to a research foundation, then to an operating company, followed by a corporate name change. The lack of correspondent information and explicit evidence for shell entities or known NPEs in the chain prevents a confident determination of NPE activity.

USPTO Assignment Center search page: https://assignmentcenter.uspto.gov/ (Search for patent number 109333370)