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:
Jul. 18, 1989
Filed:
Mar. 16, 1988
Richard K Lyon, Pittstown, NJ (US);
Energy and Environmental Research Corp., Irvine, CA (US);
Abstract
The present invention is related to a method for preventing the formation of NH.sub.4 HSO.sub.4 during the noncatalytic reduction of nitric oxide by ammonia or ammonia precursors in combustion effluents. The present invention is also related to a method for preventing the formation of H.sub.2 SO.sub.4 in the absence of ammonia or its precursors. The formation of these corrosive substances is extremely detrimental. NH.sub.4 HSO.sub.4 formation is a limitation upon the usefulness of nitric oxide reduction processes, particularly in boilers, furnaces, and other combustion devices. The formation of H.sub.2 SO.sub.4 limits effective heat recovery in combustion equipment. The present invention specifically teaches the use of methanol to reduce SO.sub.3 in the effluent stream to SO.sub.2. The noncatalytic reduction of SO.sub.3 by methanol is selective in that a large fraction of the SO.sub.3 is converted to SO.sub.2, while on a percentage basis very little oxygen is consumed. In addition, the process of the present invention allows the amount of methanol to be limited such that significant amounts of carbon monoxide are not produced and emitted with the effluent stream. By eliminating SO.sub.3, the formation of NH.sub.4 HSO.sub.4 and H.sub.2 SO.sub.4 can be blocked. The present invention teaches contacting the methanol with the combustion effluent at a temperature ranging from approximately 500.degree. C. to about 950.degree. C. in order to assure proper operation of the process. It is also important to limit the reaction time used so that the carbon monoxide produced by the methanol oxidation is not itself oxidized to carbon dioxide.