Effects of gaseous NH(3) and SO(2) on the concentration profiles of PCDD/F in flyash under post-combustion zone conditions.
Effects of gaseous NH(3) and SO(2) on the concentration profiles of PCDD/F in flyash under post-combustion zone conditions.
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DOI：
10.1016/j.wasman.2012.02.007
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发表时间：
2012-07
期刊：
影响因子：
8.1
通讯作者：
Y. Hajizadeh;J. Onwudili;Paul T. Williams
中科院分区：
文献类型：
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作者：
Y. Hajizadeh;J. Onwudili;Paul T. Williams
使用实验室规模的固定床反应器研究了气态氨和二氧化硫对城市垃圾焚烧炉的参考飞灰中 2378 取代的 PCDD/F 形成的影响。参考粉煤灰样品 (BCR-490) 在模拟烟气流下在 225 和 375°C 的温度下反应 96 小时。实验分两个系列进行：首先仅使用模拟烟气，然后将 NH3 或 SO2 气体注入反应器入口之前的烟气中。结果发现，向烟气中注入气态氨可以将固相中的 PCDD 和 PCDF 浓度降低 34-75%，气相中的 PCDD 和 PCDF 浓度降低 21-40%。将结果转换为 I-TEQ 值，可将粉煤灰和废气中 PCDD 和 PCDF 的总 I-TEQ 值分别降低 42%~75% 和 24%~57%。 SO2 的应用使固相中 PCDD 和 PCDF 的平均同系物浓度分别降低了 99% 和 93%。在气相中，PCDD 和 PCDF 的总减排量分别为 89% 和 76%。此外，SO2的添加使飞灰和废气中PCDD和PCDF的总I-TEQ值分别降低了60-86%和72-82%。在所研究的条件下，二氧化硫在抑制粉煤灰中 PCDD/F 形成方面比氨更有效。
The influence of gaseous ammonia and sulphur dioxide on the formation of 2378-substituted PCDD/F on a reference flyash from a municipal waste incinerator has been investigated using a laboratory scale fixed-bed reactor. The reference flyash samples (BCR-490) was reacted under a simulated flue gas stream at temperatures of 225 and 375°C for 96h. The experiments were carried out in two series: first with simulated flue gas alone, and then with injection of NH3or SO2gas into the flue gas just before the reactor inlet. It was found that the injection of gaseous ammonia into the flue gas could decrease the concentration of both PCDD and PCDF by 34–75% from the solid phase and by 21–40% from the gas phase. Converting the results to I-TEQ values, it could reduce the total I-TEQ values of PCDD and PCDF in the sum of the flyash and exhaust flue gas by 42–75% and 24–57% respectively. The application of SO2led to 99% and 93% reductions in the PCDD and PCDF average congener concentrations, respectively in the solid phase. In the gas phase, the total reductions were 89% and 76% for PCDD and PCDF, respectively. Moreover, addition of SO2reduced the total I-TEQ value of PCDD and PCDF in the flyash and exhaust flue gas together by 60–86% and 72–82% respectively. Sulphur dioxide was more effective than ammonia in suppressing PCDD/F formation in flyash under the conditions investigated.