磁场强化流化床铁基SCR脱硝的物理与化学效应  

Physical and Chemical Effects by Magnetic Fields for the Enhancement of De-NO_x by SCR on Iron-Based Catalyst in a Fluidized Bed

作　　者：姚桂焕[1,2] 梁辉[2] 归柯庭[2] 

机构地区：[1]南京工业大学机械与动力工程学院,江苏南京211816 [2]东南大学能源与环境学院,江苏南京210096

出　　处：《工程热物理学报》2012年第9期1535-1538,共4页Journal of Engineering Thermophysics

基　　金：国家自然科学基金资助项目(No.50576013)

摘　　要：研究了磁场对流化床铁基SCR脱硝的物理、化学作用。其物理作用体现在磁场抑制和消除流化床中的气泡,增加气固接触效率,从而增强流化床磁性Fe_2O_3催化剂SCR脱硝的传递效率。其化学作用可归结为:1)颗粒磁化产生的边界效应使顺磁性NO受Faraday力的推动,增强了NO在磁性Fe_2O_3催化剂表面的化学吸附;2)亚铁磁性铁基催化剂和磁场的协同作用,促进了反磁性反应物向顺磁性产物的磁状态转变和反应中电子的迁移,促进了NH_3在磁性Fe(III)基上的活化;3)磁场影响自由基反应体系的有序性,促进自由基NH_2与NO的反应。Physical effects and chemical effects yielded by magnetic fields on SCR of NO over the magnetic Fe2O3 catalyst were investigated. The physical effects are reflected in the enhancement of physical transfer by magnetic fields for SCR of NO on magnetic Fe2O3 catalyst in a magnetically fluidized bed （MFB）. Magnetic fields can check and eliminate bubbles in the fluidized bed. Therefore, magnetic fields can improve gas-solid contact efficiency, and then promote the transport efficiency for SCR of NO on magnetic Fe2O3 catalyst in the fluidized bed. The chemical effects are summarized as following： 1） The boundary effect, due to the magnetization of ferrimagnetic catalyst particle by uniform magnetic fields, results in Faraday force on the paramagnetic NO molecule and yields NO movement to the particle surface. Therefore, magnetic fields increase the NO chemisorption on the surface of magnetic Fe2O3 catalyst; 2） The synergy of magnetic fields and ferromagnetic iron-based catalyst can boost transforming antimagnetic reactant into paramagnetic products, and electronic transport in the reaction, thus enhancing the activation of NH3 on the magnetic Fe （III） site; 3） Magnetic fields can alert the order of free radical reaction system, thereby promoting the free radicals reaction between NH2 and NO.

关 键 词：磁流化床 铁基 SCR脱硝 传递效应 化学效应 

分 类 号：TK121[动力工程及工程热物理—工程热物理]