Table of Other Environmental Applications of Zeolites
|
Application |
Zeolite Used |
Advantages
|
|
Selective catalytic
reduction of NOx |
Copper ZSM-5; mordenite |
Good for high dust
applications. Extended temperature range. Cheaper.
Higher selectivity. Mordenite is particularly stable in acid |
|
Lean NOx |
Copper, cobalt ZSM-5;
beta |
Uses fuel hydrocarbons
as reductants. No ammonia. No
special handling. Cheaper |
|
Lean-burn (oxygen
rich) diesel engine NOx removal |
Copper, cobalt ZSM-5;
beta |
More effective than
three way catalytic converter for NOx |
|
Removal of N2O |
Cobalt, copper ZSM-5;
mordenite; ferrierite; beta; ZSM-11 |
N2O
decomposes over zeolites at higher temperature |
|
VOC removal in dilute,
high volume, humid streams |
High silica, hydrophobic
zeolites |
Effective where carbon
is not. Systems available from several vendors |
|
VOC removal during
automobile cold starts |
High silica, hydrophobic
medium, and large pore zeolite |
Achieved 35-70%
reduction |