The formation mechanism of ammonium bisulfate(ABS)during the flue gas denitrification process was presented.The effect of such parameters as the temperature

ammonia escape amount

SO3concentration

and fly ash on formation of the ABS was investigated.The analysis shows that

formation temperature of ABS is between 190℃and 240℃.The ABS exhibits as gas phase within temperature range from 320℃to 345℃

while it will decompose when the temperature is higher than 345℃.To reduce the formation of ABS

the ammonia escape amount should be reduced by controlling the mole ratio of NH3to NOx within range from 0.8to 1.2

and the oxidation rate of SO2in flue gas should be decreased as much as possible.Aiming at avoiding catalyst clogging and corrosion

it is essential to select the appropriate operation temperature to control the ABS's deposition on catalyst.