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US3984529A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for recovering sulfur by removal of sulfur dioxide from gaseous mixtures

Assignee: Individual
•
Filing: 1974-08-22
•
Granted: 1976-10-05
•
Expires: 1994-08-22
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Abstract

Abstract A process for removing sulfur dioxide from a mixture of gases and converting the removed sulfur dioxide to elemental sulfur. The sulfur dioxide is first converted to one or more condensed phase sulfite compounds by contacting the gaseous mixture with an appropriate removal reactant selected from the group consisting of certain bases, and alkali metal salts of weak acids with strong bases in aqueous solutions having a pH of at least 4. The condensed phase sulfite compounds are then reacted with certain organic nitrogen containing transfer compounds which are water insoluble to form organic soluble nitrogen containing sulfite salts disposed in an organic liquid phase. The organic, nitrogen containing sulfite salts are then, while in the organic phase, subjected to contact with hydrogen sulfide to yield elemental sulfur.

Inventors

  • 👤 Shao E Tung

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 22:32
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/02; C01B17/04; C01B17/05; B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/48; B01D53/50; B01D53/501

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

US1783901A Cited
US1946489A Cited
US2987379A Cited
US3103411A Cited
US3620674A Cited
US3633339A Cited
US3882222A Cited
US3833710A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-10-05 1980-04-05 1980-10-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-10-05 1984-04-05 1984-10-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-10-05 1988-04-05 1988-10-05 $7700.00 Window Closed / Lapsed

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