Selective catalytic reduction (SCR) of nitrogen oxides
US5143707A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1991 |
| Grant date | Sep 1, 1992 |
| Priority date | — |
| Expiry date | Jul 24, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2255/20723
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Emissions of nitrogen oxides (NO.sub.X) to the atmosphere are reduced by treatment of gases containing nitrogen oxides with a reducing agent such as ammonia in the presence of a catalyst containing a mesoporous crystalline catalyst. The mesoporous crystalline catalyst comprises an inorganic, non-layered, porous, crystalline phase aluminosilicate material which exhibits a benzene adsorption capacity of greater than about 15 grams benzene per 100 grams at 50 torr and 25.degree. C. In its preferred catalytic form, the crystalline material has a uniform, hexagonal arrangement of pores with diameters of at least about 13 .ANG. and exhibiting, after calcination, an X-ray diffraction pattern with at least on d-spacing greater than about 18 .ANG. and a hexagonal electron diffraction pattern that can be indexed with a d.sub.100 value greater than about 18 .ANG. which corresponds to at least one peak in the X-ray diffraction pattern.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.