Catalyst for reducing nitrogen oxides and process for producing the same
AssigneeUbe Industries, Ltd.
InventorsSumio Umemura, Ryozo Kitoh, Shigeru Itoh, Yasutaka Arima, Kosuke Itoh, Hideaki Fukui
Life of this patent
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Abstract
Disclosed is a water resistant catalyst for reducing nitrogen oxides with ammonia, which catalyst comprises barium sulfate and vanadium(IV)oxide sulfate which has peaks at 940 cm.sup.-1 and 510 cm.sup.-1 in an infrared absorption spectrum.
Claims14
A process for producing a catalyst usable for reducing nitrogen oxides with ammonia, said catalyst being water-insoluble and having peaks at 940.sup.cm-1 and 510.sup.cm-1 in an infrared absorption spectrum, comprising:
- preparing a mixture containing from about 65 to 99% barium sulfate and from about 1 to 35% of water-insoluble vanadium (IV) oxide sulfate which has been prepared by boiling a mixture of a vanadium oxide and concentrated sulfuric acid, said percentages based on the weight of the solids in the mixture;
- drying the resultant mixture, and;
- calcining the dried mixture at a temperature of from 200.degree. to 450.degree. C. in an oxygen-containing atmosphere.
A process for producing a catalyst useful for reducing nitrogen oxides with ammonia, said catalyst comprising a mixture containing about 65 to 99% by weight barium sulfate and about 1 to 35% by weight of vanadium (IV) oxide sulfate which is water-insoluble and has absorption peaks at 940.sup.cm-1 and 510.sup.cm-1 in the infrared spectrum, said process comprising:
- (a) forming an aqueous mixture of a vanadyl compound, corresponding to about 1 to 35% by weight of the solids of vanadium (IV) oxide sulfate, in which vanadium has a valence less than 5 and which has been prepared by dissolving a vanadium compound in an aqueous solution of a reducing substance, sulfuric acid or an ammonium salt of a sulphur-oxygen acid and from about 65 to 99% by weight of the solids of barium sulfate;
- (b) drying the resultant mixture;
- and
- (c) calcining the dried mixture at a temperature of from 200.degree. to 450.degree. C. in an oxygen-containing atmosphere.
A process for producing a catalyst useful for reducing nitrogen oxides with ammonia, said catalyst comprising a mixture containing from 65 to 99% by weight of barium sulfate and from 1 to 35% by weight of vanadium (IV) oxide sulfate which is water-insoluble and has absorption peaks in the infrared spectrum at 940.sup.cm-1 and 510.sup.cm-1, which comprises:
- (a) preparing an aqueous mixture containing from about 65 to 99% by weight of the solids of barium sulfate and an amount of water-soluble vanadyl sulfate sufficient to provide from 1 to 35% by weight of the catalyst of vanadium (IV) oxide sulfate;
- (b) drying the resultant mixture, and
- (c) calcining the dried mixture at a temperature of from 250.degree. to 450.degree. C. in an atmosphere containing sulfurous acid gas and ammonia gas to obtain said catalyst product.
A catalyst for reducing nitrogen oxides with ammonia, which comprises a uniform mixture of 65 to 99% of barium sulfate and 1 to 35% of vanadyl sulfate, based on the entire weight of said catalyst, said vanadyl sulfate being vanadium (IV) oxide sulfate which is water-insoluble and has peaks at 940 cm.sup.-1 and 510 cm.sup.-1 in an infrared absorption spectrum.
Dependencies are inferred from the claim text.