Activated carbon honeycomb catalyst beds and methods for the use thereof

Abstract

Disclosed herein, without limitation, are activated carbon honeycomb catalyst beds and systems for removing mercury and other toxic metals from a process stream, i.e, from flue gas of a coal combustion system. The activated carbon honeycomb can for example remove greater than 90% mercury from flue gas with a simple design and without adding material to the flue gas. Also disclosed herein, and without limitation, are methods for manufacturing and using the disclosed honeycomb catalyst beds and systems.

1 - 18 . (canceled) 
   
   
       19 . A method for separating mercury from a combustion flue gas, comprising the steps of:
 providing a plurality of adjacent activated carbon honeycomb monoliths having a plurality of parallel cell channels bounded by porous channel walls traversing the honeycomb monolith from an upstream inlet end to a downstream outlet end;   conveying a mercury containing combustion flue gas through at least a portion of the plurality of adjacent activated carbon monoliths.   
   
   
       20 . (canceled) 
   
   
       21 . The method of  claim 19 , wherein two or more adjacent activated honeycomb monoliths are positioned substantially parallel to each other. 
   
   
       22 . A system for non-interruptive removal of mercury from a combustion flue gas, comprising:
 a plurality of activated carbon honeycomb monoliths, wherein the plurality of monoliths are positioned in selective fluid communication with a continuous stream of a mercury containing combustion flue gas; and   a means for selectively directing the continuous stream of flue gas to at least one of the plurality of honeycomb monoliths.   
   
   
       23 . The system of  claim 22 , further comprising a mercury sensor downstream from the plurality of activated carbon honeycomb monoliths and in fluid communication with the continuous stream of flue gas. 
   
   
       24 . The system of  claim 23 , wherein the mercury sensor provides feedback indicating a concentration of mercury in the combustion flue gas downstream from the plurality of activated carbon honeycomb monoliths. 
   
   
       25 . The system of  claim 24 , wherein the means for selectively directing the continuous stream of combustion flue gas is responsive to the feedback provided by the mercury sensor when the concentration of mercury in the combustion flue gas exceeds a predetermined level. 
   
   
       26 . The system of  claim 22 , further comprising a means for replacing at least one activated carbon honeycomb monolith not in communication with the continuous stream of combustion flue gas, whereby the continuous flow of combustion flue gas is uninterrupted. 
   
   
       27 . The system of  claim 22 , wherein the means for selectively directing the continuous stream of flue gas to at least one of the plurality of honeycomb monoliths comprises a baffle. 
   
   
       28 . The system of  claim 22 , wherein the means for selectively directing the continuous stream of flue gas to at least one of the plurality of honeycomb monoliths comprises a cartridge rotatable about an axis, wherein the cartridge defines a plurality of bores configured to house a plurality of activated carbon honeycomb monoliths and wherein the cartridge can be rotated to selectively position one of the house activated carbon honeycomb monoliths in fluid communication with the continuous stream of combustion flue gas. 
   
   
       29 . A method for non-interruptive removal of mercury from a combustion flue gas, comprising the steps of:
 providing a plurality of activated carbon honeycomb monoliths, wherein the plurality of monoliths are positioned in selective fluid communication with a continuous stream of a mercury containing combustion flue gas; and   selectively directing the continuous stream of flue gas through at least one of the plurality of honeycomb monoliths.   
   
   
       30 . The method of  claim 29 , further comprising detecting the concentration of mercury in the stream of combustion flue gas downstream from the plurality of activated carbon honeycomb monoliths. 
   
   
       31 . The method of  claim 30 , selectively directing the continuous stream of combustion flue gas to a second one of the plurality of activated carbon honeycomb monoliths when the detected concentration of mercury in the combustion flue gas exceeds a predetermined level. 
   
   
       32 . The method of  claim 29 , further comprising replacing at least one activated carbon honeycomb monolith not in communication with the continuous stream of combustion flue gas, whereby during the replacement the continuous flow of combustion flue gas is uninterrupted.