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AssigneeDegussa AG
InventorsMichael Baacke, Reinhold Beand, Bernd Engler, Akos Kiss, Peter Kleine-Mollhoff, Peter Kleinschmit, Edgar Koberstein, Mustafa Siray
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A zeolite catalyst and a method for reduction of nitrogen oxides present in waste gas streams is described. The method includes mixing the waste gas containing nitrogen oxides with ammonia. At an elevated temperature, this mixture is passed over a zeolite catalyst. Preferably, the zeolite catalyst is in a monolithic or honeycomb form. The zeolite catalyst includes one or more of the following subgroup metals: copper, iron, molybdeum and cerium. The zeolite catalysts made in accordance with this invention show better conversion of nitrogen oxides and longer life than known catalysts.
A method for the reduction of oxides of nitrogen present in waste gases containing oxygen, comprising mixing the waste gases containing nitrogen oxides with ammonia gas and passing said mixture at a temperature in the range of from 200.degree.-600.degree. C. with a space velocity of 1,000- 60,000 h.sup.-1 corresponding to a catalyst area velocity of 0.5-100 m.sup.3 /h.multidot.m.sup.2 at standard temperature and pressure over a mordenite type zeolite catalyst including 0.2-5.2% by weight copper, 0.1-4.5% by weight iron and 0.1-1.0% by weight cerium relative to the zeolite weight.
A method for the reduction of oxides of nitrogen present in waste gases containing oxygen, comprising mixing the waste gases containing nitrogen oxides with ammonia gas and passing said mixture at a temperature in the range of from 200.degree.-600.degree. C. with a space velocity of 1,000-60,000 h.sup.-1 corresponding to a catalyst area velocity of 0.5-100 m.sup.3 /h.multidot.m.sup.2 at standard temperature and pressure over a mordenite type zeolite catalyst including 0.2-5.2% by weight copper, 0.1-4.5% by weight iron and 0.2-2.5% by weight molybdenum, relative to the zeolite weight.
A method for the reduction of oxides of nitrogen present in waste gases containing oxygen, comprising mixing the waste gases containing nitrogen oxides with ammonia gas and passing said mixture at a temperature in the range of from 200.degree. -600.degree. C. with a space velocity of 1,000-60,000 h.sup.-1 corresponding to a catalyst area velocity of 0.5-100 m.sup.3 /h.multidot.m.sup.2 at standard temperature and pressure over a mordenite type zeolite catalyst including b 0.2-5.2% by weight copper and 0.2-2.5% by weight molybdenum, relative to the zeolite weight.
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