Nitrogen oxide removal catalyst
US5869419A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 9, 1997 |
| Grant date | Feb 9, 1999 |
| Priority date | — |
| Expiry date | Jun 9, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J37/0244
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
This invention effectively utilizes a solid type honeycomb-shaped NO.sub.x removal catalyst which has been used in a catalytic ammonia reduction process and hence reduced in NO.sub.x removal power, and thereby provides an inexpensive catalyst having NO.sub.x removal power equal to that of a fresh catalyst. The nitrogen oxide removal catalyst of this invention, which is useful in a process wherein ammonia is added to exhaust gas and nitrogen oxides present in the exhaust gas are catalytically reduced, has a two-layer structure composed of a lower layer comprising a spent solid type nitrogen oxide removal catalyst and an upper layer comprising a fresh TiO.sub.2 -WO.sub.3 -V.sub.2 O.sub.5 ternary or TiO.sub.2 -WO.sub.3 binary catalyst powder which has been applied to the lower layer so as to give a coating thickness of 100 to 250 .mu.m. Moreover, the catalyst power constituting the upper layer is a catalyst powder obtained by pulverizing a spent solid type nitrogen oxide removal catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.