Ammonium bisulfate formation and reduced load SCR operation

Study on the formation process of low‐temperature ash deposition induced by ammonium bisulfate in pulverized coal‐fired boiler

“…Based on the composition of the flue gas, the ABS formation temperature can be calculated by the formula proposed by Muzio et al 9 :…”

“…Menasha et al 8 found that the ABS formation temperature ranged from 500 to 520 K by experimental simulation. Muzio et al 9 suggested that the formation of ABS is mainly determined by the concentration of NH 3 and SO 3 in the flue gas based on the review of the prior research, 4,8,[11][12][13] and they proposed an equation for the initial formation temperature of ABS. The above investigations focused on formation or deposition temperature of ABS.…”

“…Some researchers [4][5][6] have reported that the ash fouling problem is aggravated by the ammonium bisulfate (ABS) formed due to the combination of the ammonia (NH 3 ) slipping from SCR and the sulfur trioxide (SO 3 ) in the flue gas. On this basis, a volume of investigations were focused on either the accurate prediction of the formation mechanism of ABS 5,[7][8][9] or the methods to reduce the formation of ABS fouling. 10 Burke and Johnson 7 found that both ammonium sulfate (AS) and ABS could form in the RAPH by conducting thermodynamic and kinetic analysis of the NH 3 -SO 3 reactions.…”

Influence of operating conditions on ammonium bisulfate deposition in the rotary air preheater of coal-fired power plants

“…where TABS is the initial formation temperature of ABS which can be calculation from the Muzio's study [18], Tcoldthe temperature at cold end metal in RAPH, tg,exitthe outlet temperature of flue gas in RAPH, [SO3] and [NH3]the volume concentrations of SO3 and NH3 in the flue gas, respectively. Since the radian number only depends on the concentration of SO3 and NH3, ABS initial formation temperature and the cold end metal temperature and outlet gas temperature.…”

“…(6), Tcold top,ave and Tcold bottom,ave are the average temperatures at top and bottom boundaries of cold-layer matrix, respectively, Thot bottom,min and Thot bottom,avethe minimum and average temperatures at bottom boundaries of hot-layer matrix, respectively, Raxialthe ratio of ABS deposition height to the total cold-layer height in axial direction, and Rcirthe ratio of ABS deposition angle range to the total range of gas section in the circumferential direction in the bottom of middle-layer. TABS is the formation temperature of ABS which can be calculated by the following equation [18]. 33 Compared to the original radian number, the improved radian number is a dimensionless number and can reflect the deposition in height and circumferential directions simultaneously.…”