CPC B01D 53/885 (2013.01) [B01D 53/8634 (2013.01); B01D 53/8668 (2013.01); B01J 20/28014 (2013.01); B01D 2255/911 (2013.01); B01D 2255/912 (2013.01); B01D 2257/406 (2013.01); B01D 2257/7025 (2013.01); B01D 2257/708 (2013.01); B01J 2220/56 (2013.01)] | 13 Claims |
1. An exhaust system for the treatment of an exhaust gas comprising ammonia, the system comprising:
a first gas inlet for providing a flow of exhaust gas;
a second gas inlet for providing a flow of heated gas;
a plurality of sorbent beds, wherein each sorbent bed comprises an ammonia storage material for releasably storing ammonia, wherein the ammonia storage material is small-pore zeolite having a framework structure selected from the group consisting of AEI, AFT, AFV, AFX, AVL, CHA, EMT, GME, KFI, LEV, LTN, and SFW, including mixtures of two or more thereof;
one or more ammonia oxidation catalysts;
first and second exhaust gas outlets; and
a valve system configured to establish independently for each sorbent bed fluid communication in a first or second configuration, wherein:
i) in the first configuration the flow of the exhaust gas from the first gas inlet contacts a sorbent bed for storing ammonia and then passes to the first gas outlet; and
ii) in the second configuration the flow of heated gas from the second gas inlet contacts a sorbent bed for releasing the species, passes to one of the one or more ammonia oxidation catalysts and then passes to the second exhaust gas outlet;
wherein the valve system is configured to ensure that at least one sorbent bed is in the first configuration and, at least one other sorbent bed is in the second configuration.
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