Methods for preventing ammonium bisulfate formation during the noncatalytic reduction of nitric oxide
US4743436A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 8, 1987 |
| Grant date | May 10, 1988 |
| Priority date | — |
| Expiry date | Apr 8, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D53/60
- WIPO fieldChemical engineering
- WIPO sectorChemistry
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 formation of this sticky and corrosive substance inside combustion units is an extreme limitation upon the usefulness of nitric oxide reduction processes, particularly in boilers, furnaces, and other combustion devices. 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. The present invention contacts 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 t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.