The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 12, 2000
Filed:
Jun. 22, 1998
Rudolf Frey, Effretikon, CH;
Felix Koller, Veltheim, CH;
Von Roll Umwelttechnik AG, Zurich, DE;
Abstract
A process is provided for removing contaminants, such as nitrogen oxides, out of exhaust gases, such as gases emitted from an incineration plant. Ammonia or a reducing agent producing ammonia is added to the exhaust gases at a point where the exhaust gases are at a temperature ranging from 700 to 900.degree. C. so that ammonia reacts with and removes nitrogen oxides out of the gases; the gases are passed into a boiler where they are cooled to a temperature ranging from 200 to 350.degree. C. and additional ammonia or reducing agent is injected into the gases; the gases are removed from the boiler and alkaline sorbents, such as alkali metal compounds or alkaline earth metal compounds are injected into the gases, and the gases are passed through a catalyst/filter element coated with a catalytically active oxide or salt of vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, tungsten and molybdenum for catalyzing the reduction of residual nitrogen oxides in the flue gases. The gases discharged from the catalyst/filter element may be subjected to a wet scrubbing step to remove sulfur dioxide and/or hydrochloric acid out of the gases.