Reduction of nitrogen- and carbon-based pollutants
US4751065A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 10, 1986 |
| Grant date | Jun 14, 1988 |
| Priority date | — |
| Expiry date | Sep 10, 2006 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D53/56
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Disclosed is a process for reducing nitrogen oxides in an effluent from the combustion of a carbonaceous fuel under oxygen-rich conditions which minimize the production of carbon-based pollutants. A dispersion of a solution comprising at least one additive compound selected from the group consisting of guanidine, guanidine carbonate, biguanide, guanylurea sulfate, melamine, dicyandiamide, calcium cyanamide, biuret, 1,1'-azobisformamide, methylol urea, methylol urea-urea condensation product, dimethylol urea, methyl urea, dimethyl urea, and hexamethylenetetramine is injected into an effluent at a temperature above 1300.degree. F., and preferably above 1500.degree. F. The concentration of the additive compound in solution, the temperature of the effluent at the point of injection, and the size of the droplets in the dispersion, are selected to provide a reduction in nitrogen oxides. When urea is employed in combination with hexamethylenetetramine, the effectiveness of the urea is enhanced, particularly at temperatures 1800.degree. F. and below.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.