Simultaneous Removal of NOx and Soot in Diesel Exhaust by Using a Centrifugal Fluidized Bed

在Cu-ZSM-5沸石催化剂上对柴油机烟尘排放的氮氧化物进行了还原实验。结果表明，在有氧存在的情况下，煤烟在Cu-ZSM-5沸石催化剂上促进NO_x还原成氮。结果表明：在CU-ZSM-5沸石催化剂上，NO_2由NO和O_2反应生成，然后被烟灰部分还原为N_2；在这种催化剂上，活性炭也被观察到与烟灰一样有效地去除氮氧化物。在693 K时，脱氮速率与NO浓度成正比。根据动力学研究结果，讨论了该反应的机理。此外，为了同时去除NOx和煤烟，提出了超细催化剂颗粒离心流化床的应用。在离心流化床（CenFB）中进行了纳米颗粒的流化。在7 nm和20 nm颗粒体系的情况下，纳米颗粒流化形成团聚团，范围为9.1<G<18.5。高G纳米颗粒的流化质量不仅受原生颗粒粒径的影响，还受团聚体粒径及其结构的影响。

Reduction of nitrogen oxides emitted from a diesel engine with soot over a Cu-ZSM-5 zeolite catalyst has been experimentally. It was found that in the presence of oxygen, the soot promoted NO_x reduction into nitrogen over the Cu-ZSM-5 zeolite catalyst. Restults show that NO_2 is formed through the reaction of NO and O_2 and is then partially reduced into N_2 by soot over the CU-ZSM-5 zeolite catalyst. Activated carbon was observed to be also as effective as soot in the removal of nitrogen oxides over this catalyst. At 693 K, the rate of the nitrogen oxide removal reaction was found to be proportional to the NO concentration. The mechanisms of this reaction are discussed based on the results obtained from the kinetic study.In addition, in order to remove NOx and soot simultaneously, the application of the centrifugal fluidized bed with ultrafine catalyst particles is proposed. The fluidization of nanoparticles has been conducted in a centrifugal fluidized bed (CenFB). In the case of 7 and 20 nm particle systems, the nanoparticles are fluidized with forming agglomerates in the range of 9.1<G<18.5. The fluidization quality of nanoparticles with high G is affected by not only the primary particle size but also agglomerates size and its structure.