Simultaneous Removal Of SO₂ And NO_x In Dedusting And Desulphurization Tower With Umbrella Plates

The present situation of air pollution in China and simultaneous removal technologies of SO2 and NOx were consulted and reviewed in this paper. The importance of developing new technology of simultaneous removal of SO2 and NOx were showed clearly by summarizing the current status of thermal power plant in China. And the major methods of simultaneous removal of SO2 and NOx was introduced.The simultaneous desulphurization and denitrification performance in the Dedusting and Desulphurization Tower with Umbrella Plates (DDTUP) was studied in this paper.The simultaneous desulfurization and denitrification from flue gas using desulphurization tower with self-owned intellectual property rights was reported for the frist time in China. The structural design, the operating mechanism and the chief advantages of the DDTUP were briefly introduced.Based on simulating thermal power plant conditions, experiments on removal of SO2 and NO by using NaC102 solution were carried out. The following results found that the initial concentration of NaC102, the ratio of liquid to gas, the initial gas speed,the initial pH value and the initial concentration of SO2 and NOx had important effects on the performance of the removal efficiencies. The optimal experimental conditions of the simultaneous desulfurization and denitrification using DDTUP were acertained by analyzing the experimental results and considering the economic factors. Under the optimal conditions, the simultaneous removal efficiencies of SO2 and NO by NaC102 solution reached 85% and 67%, respectively.The mechanism of the simultaneous desulfuration and denitration using NaC102 was systematically summarized by analyzing a amount of literature about it. The yellow-green ClO2 gas which was made by NaC102 at the pH 3-4 was found having a strong oxidation. The denitrification of the NaC102 solution was showed depending crucially on ClO2 oxidation which could oxidate NO to NO2, and the further absorption of NO2 was counted as the via hydrolysis of the N2O3 and N2O4 Furthermore,reducing secondary pollution such as ClO2 by increasing the initial pH value was discussed.And the optimal initial pH value was found to be around 5 in this research for the first time.Based on the former research, the mass transfer mechanism of SO2 in the NaClO2 solution was analyzed thoroughly. By analysis, SO2 absorption process in NaC102 was a gas controlled reaction. And the computational method of the total absorption rate of SO2 in NaC102 solution was obtained. The following results found that the total absorption rate of SO2 related to the flow rate of SO2, the inlet partial pressure of SO2 and the concentrationof SO2 in the NaC102 solution.