使用固定床小型实验台和循环流化床中型实验台,研究了中温干法脱硫技术中的钙基脱除剂的脱硝性能。在700-800℃的温度范围内,由粉煤灰和石灰快速水合的脱除剂有较强的将NH,氧化成NO的性质,其活性接近石灰。脱除剂在固硫之后具有催化NH,还原NO的性质,将NH,氧化为NO的产物选择性也显著降低。中试规模的循环流化床实验结果表明,在720~740℃,氨氮比为1.71时,脱硝率达到60.33%;同时,喷入的氨除参加脱硝反应外,均被还原成N2,出口没有多余的氨泄漏。该文还提出了同时脱硫脱硝的最佳温度范围和还原剂的加入位置。
The denitrification performance of calcium- based sorbent under mid-temperature range has been investigated on a bench-scale fixed-bed reactor and a pilot-scale fluidized-bed reactor. Within the temperature window of 700-800℃, the sorbent prepared from pulverized coal ash and lime demonstrates strong tendency to oxidize NH3 to NO, however, after the sorbent reacting with SOz, the sulfated sorbent is capable to catalyze NH3 to reduce NO. The selectivity of" NI-I3 to form NO is also significantly reduced. The results of pilot-scale experiments reveal that, under 720-740 ℃, the NO removal rate could be as high as 60.33% when NH3/NO molar ratio at 1.71. The excessive NH3 was converted to N2 and no NH3 was found. The optimum temperature window for simultaneous removal of SO2 and NO, and the injection location of reducing agent were also proposed in this research.