Mercury Control Using Moderate-Temperature Dissociation of Halogen Compounds

US 8,807,056 Lapsed on the fee record

Lapsed Aug 19, 2026 on the fee record · Medium confidence

Computed 20-year base term

Why Medium: The disclaimer's references carry disclaimers of their own not yet read (US 8,312,822), so the cap could be lower.

Third maintenance fee unpaid; grace period ended.

Held by Birchtech Corp.

Filed Jul 9, 2012 as application 13/544,971 · Granted Aug 19, 2014

Base term, 20 years from filing, plus 162 days of patent term adjustment (USPTO delay)

Today

Lapsed Aug 19, 2026

2008 2028

Clock starts
Jul 2, 2008

No longer in force
Aug 19, 2026

Granted
Aug 19, 2014

Term would have run to
Dec 11, 2028

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

162

Days of term adjustment

Read from the USPTO patent term adjustment record, not recalculated here.

No effect

Terminal disclaimer

Resolved from the filed document, referencing US 8,312,822, to Dec 11, 2028. The term already ends on or before that date, so the cap shortened nothing.

2 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.

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 Jul 2, 2008, when the earliest non-provisional application in its chain was filed (this one was filed Jul 9, 2012)	Jul 2, 2028	High confidence
Continuity chain	Every parent in the chain resolved	no change	High confidence
Patent term adjustment	+162 days, USPTO patent term adjustment record	Dec 11, 2028	High confidence
Terminal disclaimer cap	Disclaimer resolved from the filed document (refs US 8,312,822)	resolves to Dec 11, 2028, no earlier than this term, so no change	Medium confidence
Patent term extension	None on file	no change	High confidence
Fee events	2 of 3 maintenance fees paid	lapsed Aug 19, 2026	High confidence
Computed term end	The steps above, in order	Aug 19, 2026	Medium confidence

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.

Not on this page: the patent's family, its recorded assignments and its citation count. USPTO's assignment records, linked above, list every recorded assignment.

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.

Mercury Control Using Moderate-Temperature Dissociation of Halogen Compounds

Lapsed Aug 19, 2026 on the fee record · Medium confidence

20-year base term ends Jul 2, 2028

How we calculated this date

Sources