Process for the manufacture of catalytic elements and catalytic elements so produced
First Claim
1. A process for the manufacture of catalytic elements, said process comprising the steps of:
- (a) providing a primary catalytic material, said primary catalytic material being a member selected from the group consisting essentially of iron oxide, a mixture of iron oxide and chromium oxide, a mixture of iron oxide and manganese oxide, and a mixture of iron oxide, chromium oxide and manganese oxide and combinations of members of the group;
(b) mixing a binder means with said primary catalytic material for binding said primary catalytic material;
(c) molding said mixed primary catalytic material and binder means produced in said step (b) to produce green catalytic elements;
(d) subjecting said green catalytic elements to a first temperature treatment of 100°
C. to 250°
C. to set said binder means;
(e) treating said catalytic elements obtained from said step (d) with a mixture of sulfuric acid and phosphoric acid; and
(f) subjecting said catalytic elements obtained from said step (e) to a second temperature treatment in the range between about 100°
C. and about 600°
C. to temper said catalytic elements.
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Abstract
This invention relates to a process for the manufacture of catalysts for the reduction of nitrogen oxides in exhaust gases or for chemical air cleaning processes, in which catalyst moldings are produced from iron oxide or mixtures of iron oxide and chromium oxide and/or manganese oxide, which are reduced to grain sizes less than 2 mm, with the use of inorganic binders and sulfuric acid, and with the possible addition of activating additives.
In accordance with the invention:
(a) either the mixture of the solid primary material is reacted with sulfuric acid, a mixture of sulfuric acid and phosphoric acid or a sulfuric acid or mixture of sulfuric acid and phosphoric acid containing sulfate, hydrogen sulfate, phosphate or hydrogen phosphate of ammonium, aluminum, iron, vanadium, manganese, molybdenum, chromium, copper and/or cobalt, and moldings are formed from this mixture, or the mixture of the solid primary material is formed into moldings after the addition of fluid and/or phosphoric acid and/or phosphates, and these moldings are treated with sulfuric acid or a sulfuric acid containing sulfate or hydrogen sulfate of ammonium, aluminum, iron, vanadium, manganese, molybdenum, chromium, copper, and
(b) then, on the moldings obtained in Step (a), a drying treatment is performed at 110° C. to 250° C., followed by a tempering treatment at 250° C. to 600° C.
The catalysts manufactured using the process described by the invention have a low sensitivity to moisture and good activity.
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Citations
24 Claims
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1. A process for the manufacture of catalytic elements, said process comprising the steps of:
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(a) providing a primary catalytic material, said primary catalytic material being a member selected from the group consisting essentially of iron oxide, a mixture of iron oxide and chromium oxide, a mixture of iron oxide and manganese oxide, and a mixture of iron oxide, chromium oxide and manganese oxide and combinations of members of the group; (b) mixing a binder means with said primary catalytic material for binding said primary catalytic material; (c) molding said mixed primary catalytic material and binder means produced in said step (b) to produce green catalytic elements; (d) subjecting said green catalytic elements to a first temperature treatment of 100°
C. to 250°
C. to set said binder means;(e) treating said catalytic elements obtained from said step (d) with a mixture of sulfuric acid and phosphoric acid; and (f) subjecting said catalytic elements obtained from said step (e) to a second temperature treatment in the range between about 100°
C. and about 600°
C. to temper said catalytic elements. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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Specification