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US5169814A Expired / Lapsed US ⏱️ 0.0 years remaining

Catalysts for denitrization

Assignee: Sakai Chemical Industry Co Ltd
•
Filing: 1989-10-05
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Granted: 1992-12-08
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Expires: 2009-10-05
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Abstract

Abstract A denitrizing catalyst with comprises: (a) a zeolite represented by the general formula (I) H.sub.A M.sub.B [(AlO.sub.2).sub.X ·(SiO.sub.2).sub.Y ]·2H 2 0 wherein M is an alkali metal or an alkaline earth metal, and A+nB=X wherein n is a valency of the metal M, in amounts of 80-99.9% by weight; and (b) at least one metal or at least one oxide of metals selected from the group consisting of Ru, Rh, Pd, Ag, Pt, Au, Co, Cu, Cr and Ni, in amounts of 0.1-20% by weight. A further denitrizing catalyst which comprises a zeolite represented by the general formula H.sub.A (M.sup.1).sub.B (M.sup.2).sub.c [(AlO.sub.2).sub.X ·(SiO 2 ) Y ]·2H Z O wherein M 1 is an alkali metal or an alkaline earth metal, M 2 is a metal selected from the group consisting of Ru, Rh, Pd, Ag, Pt, Au, Co, Cu, Cr and Ni, A+n 1 B+n 2 C=X wherein n 1 and n 2 are valecies of the metals M 1 and M 2 , respectively. Waste gases containing nitrogen oxides therein are denitrized by putting the gases into contact with the catalysts in the absence of reducing agents.

Inventors

  • 👤 Masafumi Yoshimoto
  • 👤 Tadao Nakatsuji
  • 👤 Kazuhiko Nagano

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 21:32
CPC Classifications
B; B01; B01J; B01J29/00; B01J29/04; B01J29/06; B01J29/061; B01D; B01D53/00; B01D53/34; B01D53/74; B01D53/86; B01D53/8621; B01D53/8625; B01D53/8628

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 76 words
A denitrizing catalyst which comprises a zeolite represented by the general formula H.sub.A (M.sup.1).sub.B (M.sup.2).sub.C [(AlO.sub.2).sub.X.(SiO.sub.2).sub.Y ].zH.sub.2 O wherein M 1 is an alkali metal or an alkaline earth metal, M 2 is a metal selected from the group consisting of Ru, Rh, Pd, Ag, Pt, Au, Co, Cu, Cr and Ni, and A+n 1 B+n 2 C=X wherein n 1 and n 2 are valences of the metals M 1 and M 2 , respectively.
Claim 2
Dependent Claim 76 words
A denitrizing catalyst which comprises a zeolite represented by the general formula H.sub.A (M.sup.1).sub.B (M.sup.2).sub.C [(AlO.sub.2).sub.X.(SiO.sub.2).sub.Y ].zH.sub.2 O wherein M 1 is an alkali metal or an alkaline earth metal, M 2 is a metal selected from the group consisting of Ru, Rh, Pd, Ag, Pt, Au, Co, Cu, Cr and Ni, and A+n 1 B+n 2 C=X wherein n 1 and n 2 are valences of the metals M 1 and M 2 , respectively.
Claim 3
Dependent Claim 16 words
The catalyst as claimed in claim 1 wherein A/X>0.1, n 1 B/X>0.1 and n 2 C/X>0.05.

References Cited (Backward Citations)

US3476508A Cited
US4002723A Cited
US4052337A Cited
US4735930A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-12-08 1996-06-08 1996-12-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-12-08 2000-06-08 2000-12-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-12-08 2004-06-08 2004-12-08 $7700.00 Window Closed / Lapsed

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