Also listed on Energy and Environmental Research Center Foundation, an earlier holder on the record. The recorded assignments below show how it moved.
Term ended Oct 26, 2026 · High confidence
20-year base term ended Apr 23, 2024
Held by Birchtech Corp.
Filed Jan 23, 2007 as application 10/554,018 · Granted May 8, 2012
Base term plus 916 days of patent term adjustment (USPTO delay)
Today
Term ended Oct 26, 2026
2004
2026
Clock starts
Apr 23, 2004
Apr 23, 2004
Term ended
Oct 26, 2026
Oct 26, 2026
Granted
May 8, 2012
May 8, 2012
base term
patent term adjustment
after the term ends
fee events
Updated Nov 14, 2026 · includes USPTO assignment & status data published Nov 14, 2026 and grant & fee data published Nov 10, 2026 (weekly) · how we know
916
Days of term adjustment
Read from the USPTO patent term adjustment record, not recalculated here.
None
Terminal disclaimer
No disclaimer on this record.
3 of 3
Maintenance fees paid
Three maintenance fees fall due, at 3.5, 7.5 and 11.5 years from grant. This counts the ones the record shows paid.
28
Family applications on record here
Applications sharing this one's continuity chain whose file history this site holds. The family may have others.
This patent's term runs 916 days past its 20-year base term on prosecution delay. All three maintenance fees were paid, so no fee lapse ended it. Confidence: High. from the record
How we calculated this date
One row per rule, each showing its own input and what it did to the date. A step we could not verify says so instead of resolving itself.
| Step | Input | Date after this step | Confidence |
|---|---|---|---|
| Base term, 20 years from filing | Clock starts Apr 23, 2004, when application PCT/US2004/012828, the earliest non-provisional in its chain, was filed (this one was filed Jan 23, 2007) | Apr 23, 2024 | High confidence |
| Continuity chain | Every parent in the chain resolved | no change | High confidence |
| Patent term adjustment | +916 days, USPTO patent term adjustment record | Oct 26, 2026 | High confidence |
| Terminal disclaimer cap | None on record | no cap applied | High confidence |
| Patent term extension | None on file | no change | High confidence |
| Fee events | 3 of 3 maintenance fees paid | term ended | High confidence |
| Computed term end | The steps above, in order | Oct 26, 2026 | High confidence |
This family
| US 7,435,286 | Term ended Mar 2026 | Mar 2026 |
| US 8,173,566 | this patent Oct 2026 | Oct 2026 |
| Application 12/201,595 | Abandoned not computed | not computed |
| US 8,168,147 | Term ended Aug 2025 | Aug 2025 |
| US 8,652,235 | Term ended Jan 2026 | Jan 2026 |
| US 8,440,585 | Lapsed on the fee record May 2021 | May 2021 |
| US 8,512,655 | Term ended Aug 2025 | Aug 2025 |
| US 8,821,819 | Term ended Aug 2025 | Aug 2025 |
8 of 28 applications in this family shown, earliest filings first. The applications whose file history this site holds. The family may have others.
Assignments
Assignment documents as recorded at the USPTO, oldest first, with the reel and frame each was recorded at. A recorded assignment is a filed document, not a statement of current ownership, and the absence of a later one is not evidence that the last one still stands.
| Recorded | Assignor | Assignee | Conveyance |
|---|---|---|---|
| Mar 22, 2006 Reel 17342, frame 625 | Olson, Edwin S.; Pavlish, John H.; Holmes, Michael J. | Energy & Environmental Research Center Foundation | Assignment of Assignor's Interest |
| Aug 29, 2014 Reel 33643, frame 339 | Pavlish, John H. | Energy and Environmental Research Center Foundation | Assignment of Assignor's Interest |
| Aug 29, 2014 Reel 33643, frame 436 | Olson, Edwin S. | Energy and Environmental Research Center Foundation | Assignment of Assignor's Interest |
| Aug 29, 2014 Reel 33643, frame 538 | Holmes, Michael J. | Energy and Environmental Research Center Foundation | Assignment of Assignor's Interest |
| Sep 9, 2014 Reel 33698, frame 612 | Olson, Edwin S. | Energy and Environmental Research Center Foundation | Corrective Assignment to Correct the Receiving Party's Address Previously Recorded on Reel 033643 Frame 0436. Assignor(S) Hereby Confirms the Assignment. |
| Jun 8, 2017 Reel 42647, frame 351 | Energy and Environmental Research Center Foundation | Midwest Energy Emissions Corp. | Assignment of Assignor's Interest |
| Mar 11, 2020 Reel 52144, frame 657 | Energy and Environmental Research Center Foundation | Midwest Energy Emissions Corp. | Corrective Assignment to Correct the Correct the Address of the Receiving Party Previously Recorded on Reel 042647 Frame 0351. Assignor(S) Hereby Confirms the Assignment. |
| Nov 7, 2024 Reel 69187, frame 413 | Midwest Energy Emissions Corp. | Birchtech Corp. | Change of Name |
Sources
Google Patents · The patent document at USPTO · Assignment records at USPTO
USPTO account required: This application in Patent Center · USPTO's maintenance fee lookup
Maintenance fee events come from USPTO's own fee records. Its fee lookup asks for the patent number and the application number.
What's changing
Note
The 916 days of patent term adjustment (USPTO delay) are read from the USPTO record, not recalculated by us
Citations
77
later US patents cite this one
That is top 10% of utility patents granted in 2012 in our data, the only group it is compared against.
How we rank
Every date shows its work: the base term, any term adjustment or extension, any disclaimer cap, and the maintenance fee record, each with a confidence tier. How this record was built
Computed patent terms end on the dates shown. Related patents and pending applications may cover overlapping subject matter.