Abstract:
The release behavior of Hg captured on V
2O
5/AC during regeneration and temperature programmed desorption (TPD) processes was studied. The Hg
0 capture capability of the regenerated V
2O
5/AC was also tested. It was found that 81% or 94% of Hg captured on V
2O
5/AC can be released during the thermal (Ar, 400℃) or NH
3 (NH
3/Ar, 300℃) regeneration processes. The released Hg is mainly in the form of Hg
0 due to the reduction activity of carbon in AC. The TPD-AFS profile reveals that the release behavior of Hg under Ar and NH
3/Ar atmospheres is different. NH
3 in the atmosphere improved the release of Hg by lowering the highest release temperature to 300℃. Under pure Ar atmosphere the release of Hg still can be observed above 400℃. It caused the difference in Hg release ratio respect with the two regeneration processes tested. However, when NH
3 concentration increases from 1% to 5% or higher the Hg release ratio is unchanged. If the higher regeneration temperature was used the difference in Hg release ratio during the two regeneration processes should vanish. Regeneration methods have slight effects on Hg
0 capture capability on V
2O
5/AC. The Hg
0 capture capability of regenerated V
2O
5/AC under the two processes is similar, which is lower than that of the fresh V
2O
5/AC but still much higher than that of AC.