Process to prepare adsorbents from organic fertilizer and their applications for removal of acidic gases from wet air streams

Abstract

The invention is directed to an adsorbent comprising: a) 20-30% porous carbon with incorporated organic nitrogen species; and b) 70-80% inorganic matter. The invention is directed to a method of making an adsorbent which comprises: a) thermally drying dewatered sewage sludge to form granulated organic fertilizer; and b) pyrolyzing said the organic fertilizer at temperatures between 600 and 1000° C. The invention is additionally directed to the process of removing acidic gases from wet air streams comprising putting an adsorbent in contact with the wet air stream and allowing the adsorbent to adsorb the acidic gases.

1 - 28 . (canceled) 
     
     
         29 . An adsorbent derived from dewatered sewage sludge, comprising:
 20-30% porous non-activated carbon; and   70-80% inorganic matter,   wherein the adsorbent has a basic pH, and   wherein the adsorbent maintains a basic pH after hydrogen sulfide adsorption to a breakthrough capacity.   
     
     
         30 . The adsorbent as defined in  claim 29 , wherein said carbon is present as an organic nitrogen species. 
     
     
         31 . The adsorbent as defined in  claim 30 , wherein said the nitrogen species comprise amine or pyridine groups. 
     
     
         32 . The adsorbent as defined in  claim 29 , wherein the pH of the adsorbent is greater than 10. 
     
     
         33 . The adsorbent as defined in  claim 29 , wherein the adsorbent reacts with hydrogen sulfide to produce elemental sulfur and salt forms thereof. 
     
     
         34 . An adsorbent as defined in  claim 29 , wherein said adsorbent has a surface area of 100-500 m 2 /g. 
     
     
         35 . An adsorbent as defined in  claim 34 , wherein said adsorbent has a surface area of 100-200 m 2 /g.