Study On Flue Gas Desulfurization And Denitrification Characteristics Of Transitional Metal Ion Chelating TiO 2 Modified Carbon Nanotubes (MWCNTs)

A large amount of SO2and NOx are discharged during the combustion of coal, which causes a serious trouble to environment. Accordingly, the research for SO2and NOx control has received wide-ranging attention. The limestone-gypsum wet flue-gas desulfurization and the selective catalytic reduction of NOx perform well in the pollutants control. However, they also have some visible drawbacks, for example high investment, huge operating cost and large occupied area. This thesis sponsored by National Natural Science Foundation of China (50976049), Natural Science Foundation of Jiangsu Province (BK2011788) and Research Innovation Program for College Graduates of Jiangsu Province (CXLX12-0410), has focused on the study of simultaneous desulfurization and denitration on TiO2supported by MWCNTs (MWCNTs/TiO2) and Cu or Mn doped TiO2supported by MWCNTs (MWCNTs/Cu-TiO2or MWCNTs/Mn-TiO2). This thesis has obtained some basic data about physicochemical properties and desulfurization and denitration performance.The MWCNTs/TiO2, MWCNTs/TiO2chelated by Cu and Mn prepared in a sol-gel method were characterized by TEM, XRD, EDS, Raman, XPS and UV-Vis. Moreover, the performance of prepared photocatalysts on SO2and NO removal were studied experimentally in the fixed-bed reactor.TEM results revealed that TiO2were supported by MWCNTs. Moreover, the introduction of MWCNTs, Cu and Mn did not affect the crystalline phase of TiO2. MWCNTs/TiO2, MWCNTs/Cu-TiO2and MWCNTs/Mn-TiO2consisted mainly of anatase. XPS analysis confirmed the close connection between MWCNTs and TiO2, namely the formation of Ti-O-C. Moreover, Cu existed in multivalent states on MWCNTs/Cu-TiO2surface, while Mn existed as Mn2+on MWCNTs/Mn-TiO2surface. UV-Vis analysis showed the significantly improved adsorption in the UV and Visible region on10%MWCNTs/Cu-TiO2and0.5%MWCNTs/Mn-TiO2.The oxidation and removal efficiencies of SO2and NO in simulated flue gas were investigated experimentally in a fix-bed reactor. MWCNTs/TiO2had better simultaneous SO2and NO removal compared to bare TiO2, and the increasing concentration of O2and H2O were conducive to simultaneous SO2and NO removal. In the parallel tests of (MWCNTs/TiO2and MWCNTs/Cu-TiO2) and (MWCNTs/TiO2and MWCNTs/Cu-TiO2), only10%MWCNTs/Cu-TiO2and0.5%MWCNTs/Mn-TiO2revealed better SO2and NO removal. The inclusion of Cu and Mn changed the electric structure and crystalline size of TiO2, which contributed to the improved SO2and NO removal of10%MWCNTs/Cu-TiO2and0.5%MWCNTs/Mn-TiO2.