US3907975A — Catalytic oxidation of ammonia

Claim 1

Independent Claim 113 words

IN A METHOD FOR THE CATALYTIC OXIDATION OF AMMONIA COMPRISING PASSING A MIXTURE OF AMMONIA AND AIR OVER A CATALYST UNDER AMMONIA OXIDATION CONDITIONS, THE IMPROVEMENT WHEREIN SAID CATALYST COMPRISES: A COMPOSITION, CONTAINING NO MEMBERS OF THE PLATINUM GROUP, WITH LIMITED POROSITY, WITH SPECIFIC SURFACE AREA BETWEEN 0.02 AND 2M2/G, WHEREIN SAID COMPOSITION CONSISTS ESSENTIALLY OF METALLIC OXIDES CONSISTING OF IRON OXIDE, VANADIUM OXIDE AND AT LEAST ONE FURTHER METALLIC OXIDE, SELECTED FROM THE GROUP CONSISTING OF OXIDES OF NICKEL, COBALT, AND BISMUTH, AND A REFRACTORY MATERIAL CONSISTING OF MAGNESIA, SILICA, ZIRCONIA OR A MIXTURE THEREOF, ALL COMBINED BY MIXING THE POWDERED CONSTITUENTS, COMPRESSING AT 1,000-10,000 BARS AND SINTERING AT 1300*C OR HIGHER.

Claim 2

Dependent Claim 113 words

IN A METHOD FOR THE CATALYTIC OXIDATION OF AMMONIA COMPRISING PASSING A MIXTURE OF AMMONIA AND AIR OVER A CATALYST UNDER AMMONIA OXIDATION CONDITIONS, THE IMPROVEMENT WHEREIN SAID CATALYST COMPRISES: A COMPOSITION, CONTAINING NO MEMBERS OF THE PLATINUM GROUP, WITH LIMITED POROSITY, WITH SPECIFIC SURFACE AREA BETWEEN 0.02 AND 2M2/G, WHEREIN SAID COMPOSITION CONSISTS ESSENTIALLY OF METALLIC OXIDES CONSISTING OF IRON OXIDE, VANADIUM OXIDE AND AT LEAST ONE FURTHER METALLIC OXIDE, SELECTED FROM THE GROUP CONSISTING OF OXIDES OF NICKEL, COBALT, AND BISMUTH, AND A REFRACTORY MATERIAL CONSISTING OF MAGNESIA, SILICA, ZIRCONIA OR A MIXTURE THEREOF, ALL COMBINED BY MIXING THE POWDERED CONSTITUENTS, COMPRESSING AT 1,000-10,000 BARS AND SINTERING AT 1300*C OR HIGHER.

Claim 3

Dependent Claim 42 words

A method in accordance with claim 1 wherein said conditions comprise a flow rate of ammonia and air between 10,000 and 500, 000 Nl/h. per liter catalyst under pressures lying between 1 bar and 60 bars, with an inlet temperature around 150*C.

Claim 4

Dependent Claim 22 words

A method in accordance with claim 1 in which the mixture of ammonia and air contains 5 to 14% ammonia by volume.

Claim 5

Dependent Claim 18 words

A method in accordance with claim 1 in which the mixture is ammonia and air enriched with oxygen.

Claim 6

Dependent Claim 60 words

A method in accordance with claim 1, wherein the contents by weight of said metallic oxides, when present in said composition, are from 0.5 to 20% for Fe3O4, from 9 to 80% for Fe2O3, from 4 to 20% for NiO, from 4 to 20% for CoO, from 0.5 to 10% for V2O5 and from 4 to 20% for bismuth oxide.

Claim 7

Dependent Claim 27 words

A method in accordance with claim 1 wherein the contents by weight of said refractory material in said compound are 10-60% MgO, 0.2-10% SiO2 and 5-50% ZrO2.

Claim 8

Dependent Claim 120 words

In a method for the catalytic oxidation of ammonia in a fluidized bed comprising introducing a mixture of ammonia and air into a fluidized bed of catalyst under ammonia oxidation conditions, the improvement wherein said catalyst comprises: a composition, containing no members of the platinum group, with limited porosity, with specific surface area between 0.02 and 2m2/g, wherein said composition consists essentially of metallic oxides consisting of iron oxide, vanadium oxide and at least one further metallic oxide selected from the group consisting of oxides of nickel, cobalt, and bismuth, and a refractory material consisting of magnesia, silica, zirconia or a mixture thereof, all combined by Mixing the powdered constituents, compressing at 1,000-10,000 bars and sintering at 1300*C or higher.

Claim 9

Dependent Claim 120 words

In a method for the catalytic oxidation of ammonia in a fluidized bed comprising introducing a mixture of ammonia and air into a fluidized bed of catalyst under ammonia oxidation conditions, the improvement wherein said catalyst comprises: a composition, containing no members of the platinum group, with limited porosity, with specific surface area between 0.02 and 2m2/g, wherein said composition consists essentially of metallic oxides consisting of iron oxide, vanadium oxide and at least one further metallic oxide selected from the group consisting of oxides of nickel, cobalt, and bismuth, and a refractory material consisting of magnesia, silica, zirconia or a mixture thereof, all combined by Mixing the powdered constituents, compressing at 1,000-10,000 bars and sintering at 1300*C or higher.

Claim 10

Dependent Claim 42 words

A method in accordance with claim 7, wherein said conditions comprise a flow rate of ammonia and air between 3, 500 and 20,000 Nl/h per liter catalyst, under pressure lying between 1 and 60 bars and at temperatures between 500* and 800*C.

Claim 11

Dependent Claim 22 words

A method in accordance with claim 7 in which the mixture of ammonia and air contains 5 to 14% ammonia by volume.

Claim 12

Dependent Claim 18 words

A method in accordance with claim 7 in which the mixture is ammonia and air enriched with oxygen.

Claim 13

Dependent Claim 60 words

A method in accordance with claim 7 wherein the contents by weight of said metallic oxides, when present in said composition, are from 0.5 to 20% for Fe3O4, from 9 to 80% for Fe2O3, from 4 to 20% from NiO, from 4 to 20% for CoO, from 0.5 to 10% for V2O5, and from 4 to 20% for bismuth oxide.

Claim 14

Dependent Claim 27 words

A method in accordance with claim 7 wherein the contents by weight of said refractory material in said compound are 10-60% MgO, 0.2-10% SiO2 and 5-50% ZrO2.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1978-09-22	1979-03-24	1979-09-23	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1982-09-22	1983-03-24	1983-09-23	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1986-09-22	1987-03-24	1987-09-23	$7700.00	Window Closed / Lapsed

Catalytic oxidation of ammonia

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