Zhan Ming-Xiu, Fu Jian-Ying, Ji Long-Jie, Deviatkin Ivan, Lu Sheng-Yong
College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou, 310018, China; State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China.
China United Engineering Corporation, Hangzhou, 310052, China; State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China.
Chemosphere. 2018 Jan;191:895-902. doi: 10.1016/j.chemosphere.2017.10.104. Epub 2017 Oct 24.
This study investigates the efficiencies and mechanisms of the catalytic degradation of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) first, in simulated laboratory conditions and then, in a commercial municipal solid waste incineration (MSWI) plant. Five commercially available VO-WO/TiO (VWTi) catalysts were tested. The degradation efficiency of PCDD/Fs in the simulated flue gas ranged 22.8-91.7% and was generally higher than that in the MSWI flue gas of 8.0-85.4%. The degradation efficiency of PCDD/Fs in the real flue gas of the MSWI plant was largely hindered by the complex composition of the flue gas, which could not be completely reproduced in the simulated laboratory conditions. Furthermore, the degradation of the higher chlorinated PCDD/Fs was easier compared to the lower chlorinated ones in the presence of the VWTi catalysts, which was primarily driven by the tendency of the higher chlorinated PCDD/Fs to be adsorbed on the surface of the catalyst and further destructed due to their lower vapor pressure. In addition, powdered catalysts should be preferred over the honeycomb shaped ones as they exposed higher PCDD/Fs degradation efficiencies under equal reaction conditions. The chemical composition and a range of the relevant to the study properties of the catalysts, such as surface area, crystallinity, oxidation ability, and surface acidity, were analyzed. The study ultimately supports the identification of the preferred characteristics of the VWTi catalysts for the most efficient degradation of toxic PCDD/Fs and elucidates the corresponding deactivation reasons of the catalysts.
本研究首先在模拟实验室条件下，然后在商业城市固体废物焚烧（MSWI）厂中，研究了多氯二苯并对二恶英和呋喃（PCDD/Fs）催化降解的效率和机制。测试了五种市售的VO-WO/TiO（VWTi）催化剂。PCDD/Fs在模拟烟气中的降解效率为22.8-91.7%，一般高于其在MSWI烟气中的降解效率（8.0-85.4%）。MSWI厂实际烟气中PCDD/Fs的降解效率在很大程度上受到烟气复杂成分的阻碍，而这种成分在模拟实验室条件下无法完全重现。此外，在VWTi催化剂存在的情况下，高氯代PCDD/Fs比低氯代PCDD/Fs更容易降解，这主要是由于高氯代PCDD/Fs倾向于吸附在催化剂表面，并因其较低的蒸气压而进一步分解。此外，在相同反应条件下，粉末状催化剂比蜂窝状催化剂具有更高的PCDD/Fs降解效率，因此应优先选用。分析了催化剂的化学成分以及一系列与研究相关的性质，如表面积、结晶度、氧化能力和表面酸度。该研究最终支持确定VWTi催化剂对有毒PCDD/Fs最有效降解的优选特性，并阐明了催化剂相应的失活原因。
