Experimental study on integrated desulfurization and denitrification of low-temperature flue gas by oxidation method

Abstract

In this paper, TiO2 catalysts doped with different Fe contents (Fe-TiO2 catalysts) were prepared by coprecipitation method and the Fe loading capacity was optimized, and then the integrated pollutant removal experiment was conducted, in which TiO2 doped with Fe as catalyst and H2O2 as oxidant. The results show that under the condition of constant H2O2/(SO2 + NO) molar ratio, low concentration of SO2 can promote the oxidation and removal efficiency of NO, while high concentration of SO2 can inhibit the removal of NOx. The pollutant removal efficiency is proportional to the amount of catalyst, liquid–gas ratio and pH value of the absorbing solution. The optimal experimental conditions are H2O2/(SO2 + NO) molar ratio 1.5, space velocity ratio 10,000 h−1, H2O2 mass fraction 10 wt%, liquid gas ratio 10, pH 10. Correspondingly, NO oxidation efficiency reaches 88%, NOx removal efficiency 85.6%, and SO2 is almost completely removed. The microstructure of the catalyst before and after the reaction was characterized, and the crystal structure did not change obviously. However, with the deepening of the reaction, the specific surface area of the catalyst decreases, and the catalytic effect decreases slightly.