Conversion of nitrogen oxides in the presence of a catalyst...

Details Conversion of nitrogen oxides in the presence of a catalyst... Conversion of nitrogen oxides in the presence of a catalyst...

2000-10-13

2003-03-18

Tran, Hien (Department: 1764)

Chemical apparatus and process disinfecting, deodorizing, preser

Chemical reactor

Waste gas purifier

C422S171000, C422S177000, C422S222000

Reexamination Certificate

active

06534022

ABSTRACT:

This invention relates to the conversion of nitrogen oxides, such as NO and NO
2
, and more particularly, to the conversion of nitrogen oxides in the presence of a catalyst supported on a mesh-like structure.
Nitrogen oxides, such as NO and NO
2
, are undesired by-products found in exhaust gases in various plants such as power plants, including natural gas-fired power plants, waste-to-energy plants, and fuel combustion plants. Nitrogen oxides also may be found in the combustion products of diesel engines.
U.S. Pat. No. 4,280,926 discloses a method for producing a catalytic material for reduction of nitrogen oxides utilizing ammonia as reducing agent. The support material has the shape of a fibrous sheet consisting of non-metallic inorganic fibers mixed with a catalytic active powder. The product can be further treated by impregnation in catalytically active agents. The sheets can be shaped to a honeycomb structure and fixated by a silica solution adhesive.
U.S. Pat. No. 4,416,800 discloses a method for producing a catalytic material. The support material has the shape of a fibrous sheet consisting of non-metallic inorganic fibers mixed with a catalyst carrier powder. The product can be further treated by impregnation in slurry or solution containing carrier materials and catalytically active agents. The catalytic material can be used for:
a) reduction of nitrogen oxides in the presence of ammonia (catalyst: Cu, Fe, V, W and Mo on Al
2
O
3
or TiO
2
)
b) oxidation of carbon monoxide and hydrocarbons (catalyst: Pt on Al
2
O
3
or TiO
2
)
In accordance with an aspect of the present invention, there is provided a process for removing at least one nitrogen oxide from a fluid, in particular a gas. The process comprises converting the at least one nitrogen oxide in the presence of a catalyst supported on a mesh-like structure. The mesh-like structure preferably has a porosity of greater than 85%. Preferably the mesh-like structure is fibrous and made of a metal, metal and ceramic or a ceramic.
In a further aspect the mesh-like structure has a porosity of greater than 90%.
In a still further aspect, the at least one nitrogen oxide is selected from the group consisting of NO and NO
2
and N
2
O.
In a further aspect, the at least one nitrogen oxide is selected from the group consisting of NO and NO
2
or mixtures thereof. In another aspect, the at least one nitrogen oxide is NO. In another aspect, the at least one nitrogen oxide is NO
2
. In another embodiment, at least one nitrogen oxide is N
2
O. In yet another aspect, the at least one nitrogen oxide includes NO and NO
2
. In yet another aspect, the at least one nitrogen oxide includes NO, NO
2
and N
2
O.
In a further aspect, the catalyst is coated on the mesh-like structure and preferably the coating thickness is less than 30 microns.
In a still further aspect, a process for removing NO from a gas comprises oxidizing the contained NO to NO
2
and contacting the NO
2
with a metal carbonate, bicarbonate or hydroxide supported on a mesh-like structure, the mesh-like structure comprising a fibrous material of at least one of a metal, metal and ceramic or ceramic and having a porosity of at least 87%.


REFERENCES:
patent: 2627531 (1953-02-01), Vogt
patent: 4027476 (1977-06-01), Schmidt
patent: 4038214 (1977-07-01), Gotoh et al.
patent: 4113660 (1978-09-01), Abe et al.
patent: 4280926 (1981-07-01), Abe et al.
patent: 4399185 (1983-08-01), Petrow
patent: 4416800 (1983-11-01), Abe et al.
patent: 4446250 (1984-05-01), Niwa et al.
patent: 4464482 (1984-08-01), Bird et al.
patent: 4520124 (1985-05-01), Abe et al.
patent: 4608361 (1986-08-01), Kanamori et al.
patent: 4762956 (1988-08-01), Liu et al.
patent: 4902418 (1990-02-01), Ziegler
patent: 4921641 (1990-05-01), Lavin
patent: 4939113 (1990-07-01), Tauster et al.
patent: 4965243 (1990-10-01), Yamada et al.
patent: 5080963 (1992-01-01), Tatarchuk et al.
patent: 5096663 (1992-03-01), Tatarchuk
patent: 5102745 (1992-04-01), Tatarchuk et al.
patent: 5162287 (1992-11-01), Yoshimoto et al.
patent: 5165899 (1992-11-01), Delaunay et al.
patent: 5179061 (1993-01-01), Haerle
patent: 5235102 (1993-08-01), Palmer et al.
patent: 5304330 (1994-04-01), Tatarchuk et al.
patent: 5425236 (1995-06-01), Haerle
patent: 5476783 (1995-12-01), Mutsakis et al.
patent: 5490977 (1996-02-01), Wan et al.
patent: 5541147 (1996-07-01), Friedlander et al.
patent: 5582810 (1996-12-01), Tretjak
patent: 5587136 (1996-12-01), Ikeyama et al.
patent: 5651946 (1997-07-01), Dekumbis et al.
patent: 5665321 (1997-09-01), Campbell et al.
patent: H1682 (1997-10-01), Brown et al.
patent: 5753583 (1998-05-01), Heineke et al.
patent: 5762885 (1998-06-01), Debbage et al.
patent: 5795456 (1998-08-01), Friedman et al.
patent: 5800790 (1998-09-01), Imamura et al.
patent: 5997829 (1999-12-01), Sekine et al.
patent: 5997830 (1999-12-01), Itoh et al.
patent: 6056928 (2000-05-01), Fetzer et al.
patent: 2001/0014302 (2001-08-01), Bussche et al.
patent: 3923094 (1991-01-01), None
patent: 4206812 (1992-09-01), None
patent: 198 05 444 (1999-08-01), None
patent: 0 441 062 (1991-08-01), None
patent: O 574 012 (1993-12-01), None
patent: 0 903 476 (1999-03-01), None
patent: WO 95/35152 (1995-12-01), None
patent: WO96/37288 (1996-11-01), None
patent: WO99/15715 (1999-04-01), None
patent: WO00/53904 (2000-09-01), None
Christopher J. Marrion et al,Composite fiber structures for catalysts and electrodes, Journal of Power Sources, 47 (1994) 297-302.

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