KEPCO Journal on Electric Power and Energy

Korea Electric Power Corporation (한국전력공사)
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Physico-chemical Characteristics of Ammonia Adsorbed Fly Ash (AAFA)

  • Kim, Jae-kwan (KEPCO's Research Institute, Korea Electric Power Corporation) ;
  • Park, Seok-un (KEPCO's Research Institute, Korea Electric Power Corporation) ;
  • Hong, Jin-pyo (KEPCO's Research Institute, Korea Electric Power Corporation)
  • Received : 2018.04.13
  • Accepted : 2018.06.15
  • Published : 2018.06.30
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Abstract

Ammonia Adsorbed Fly Ash (AAFA) samples produced from coal fired plants equipped with SNCR (Selective Non-Catalytic Reduction) of nitrogen oxides with urea have been chemically analyzed, and their physical and dissolution properties have been investigated. XRD results for the ammonia component in AAFA ascertained that ABS (ammonium bisulfate) and AS (ammonium sulfate) were deposited on fly ash as $SO_3$ reacted with unreacted ammonia at SNCR. SEM and EDS images showed that fine ashes on large fly ash surface of sphere type were agglomerated, due to adhesive role of ammonium salts attached fly ashes. Dissolution test results of ammonium salts absorbed on AAFA in distilled water or sea water showed that the proportion of un-ionized $NH_3$ to $NH_4{^+}$ were primarily a function of pH and temperature. Increasing pH and temperature causes an increase in the fraction of un-ionized $NH_3$. At pHs of 9.6 and 10.7, un-ionized $NH_3$ and $NH_4{^+}$ ions are present in equal amounts at distilled water and sea water, respectively.

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References

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