Assignment history

Inventors

• Edwin S. Olson: Employed by Energy & Environmental Research Center Foundation (EERC Foundation) at the time of filing, as indicated by the assignment of his interest to EERC Foundation on 2019-09-23.
• Michael J. Holmes: Employed by Energy & Environmental Research Center Foundation (EERC Foundation) at the time of filing, as indicated by the assignment of his interest to EERC Foundation on 2019-09-23.
• John H. Pavlish: Employed by Energy & Environmental Research Center Foundation (EERC Foundation) at the time of filing, as indicated by the assignment of his interest to EERC Foundation to EERC Foundation on 2019-09-23.

It appears all three inventors were affiliated with the Energy & Environmental Research Center Foundation, which subsequently assigned its interest to Midwest Energy Emissions Corp.

Original assignee

The original assignee listed on the issued patent US10926218B2 is Midwest Energy Emissions Corp.. Midwest Energy Emissions Corp. (MEEC) is a public company (OTCQB: MEEC) that develops and delivers mercury emissions control technologies and services for the coal-fired power industry and other industrial sources. They ship products embodying the claims, specifically sorbents for mercury removal. Their current status is operating.

Assignment timeline

• 2019-09-23 (executed) / recorded 2019-09-23 — Reel 050462/0607
  • Conveyance: Assignment
  • Assignor: Edwin S. Olson; Michael J. Holmes; John H. Pavlish
  • Assignee: Energy and Environmental Research Center Foundation
  • Correspondent: R. Patrick W. Stark, PH.D., N.D. Patent Law Firm, 1100 University Ave, Grand Forks, ND, 58202-0002.
  • Context: Internal transfer of inventor interests to their affiliated research foundation.
• 2019-09-23 (executed) / recorded 2019-09-23 — Reel 050462/0607
  • Conveyance: Assignment
  • Assignor: Energy and Environmental Research Center Foundation
  • Assignee: Midwest Energy Emissions Corp.
  • Correspondent: R. Patrick W. Stark, PH.D., N.D. Patent Law Firm, 1100 University Ave, Grand Forks, ND, 58202-0002. (This correspondent recurs in this chain.)
  • Context: Transfer of patent rights from research foundation to commercial entity.
• 2020-03-11 (executed) / recorded 2020-03-12 — Reel 051052/0178
  • Conveyance: Corrective Assignment
  • Assignor: Energy and Environmental Research Center Foundation
  • Assignee: Midwest Energy Emissions Corp.
  • Correspondent: R. Patrick W. Stark, PH.D., N.D. Patent Law Firm, 1100 University Ave, Grand Forks, ND, 58202-0002. (This correspondent recurs in this chain.)
  • Context: Corrective assignment to update assignee address.
• 2024-11-07 (executed) / recorded 2024-11-08 — Reel 063518/0636
  • Conveyance: Change of Name
  • Assignor: Midwest Energy Emissions Corp.
  • Assignee: Birchtech Corp.
  • Correspondent: R. Patrick W. Stark, PH.D., N.D. Patent Law Firm, 1100 University Ave, Grand Forks, ND, 58202-0002. (This correspondent recurs in this chain.)
  • Context: Name change of the assignee from Midwest Energy Emissions Corp. to Birchtech Corp.

Timeline diagram

timeline
    title Ownership of US 10926218
    2019 : Inventors assigned to EERC Foundation
         : EERC Foundation assigned to Midwest Energy Emissions Corp
    2020 : Corrective Assignment 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 — not present. The initial assignee, Midwest Energy Emissions Corp., is an operating company that offers mercury emissions control technologies. The current assignee, Birchtech Corp., is a name change of the same operating company.
2. Known asserter in the chain — not present. Neither Midwest Energy Emissions Corp. nor Birchtech Corp. are identified on common NPE lists.
3. Repeat correspondent across the chain — present. R. Patrick W. Stark, PH.D., of N.D. Patent Law Firm (1100 University Ave, Grand Forks, ND, 58202-0002) is listed as the correspondent for all four recorded assignments (Reel 050462/0607, Reel 051052/0178, and Reel 063518/0636).
4. Cascading transfers — not present. The transfers occur over several years, and the initial transfers in 2019 are internal.
5. Pre-litigation transfer — unclear. While the patent family has litigation, the specific assignment to Birchtech Corp. (via name change) occurred in November 2024, and the earliest listed litigation on Google Patents is in Iowa Southern District Court (4:24-md-03132) filed in 2024-11-07, which is the same date as the name change executed date. However, without knowing the exact date the lawsuit was filed, it's difficult to definitively say if it was before or after the effective date of the name change.
6. Bankruptcy fire-sale — not present. There is no indication that Midwest Energy Emissions Corp. or Birchtech Corp. have undergone bankruptcy proceedings.
7. Privateering — not present. There is no evidence suggesting that Midwest Energy Emissions Corp. or Birchtech Corp. transferred the patent to an NPE to assert on their behalf.
8. Defensive aggregator (anti-NPE) — not present. The chain does not terminate at a known defensive aggregator.

Verdict

Operating-company assertion. The primary assignee, Midwest Energy Emissions Corp. (now Birchtech Corp. via name change), is a public operating company that ships products related to the claimed technology. The patent has been involved in litigation, which is consistent with an operating company asserting its intellectual property. The recurring correspondent, while noted, is also consistent with an operating company utilizing a consistent legal counsel for its patent portfolio.

US10926218B2 - Sorbents for the oxidation and removal of mercury - Google Patents. https://patents.google.com/patent/[US10926218](/patent/US10926218)/en (Accessed July 1, 2026).
MIDWEST ENERGY EMISSIONS CORP. https://www.meemc.com/ (Accessed July 1, 2026).
USPTO Patent Assignment Search. https://assignmentcenter.uspto.gov/ (Accessed July 1, 2026).