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

Abstract In this paper, TiO 2 catalysts doped with different Fe contents (Fe-TiO 2 catalysts) were prepared by coprecipitation method and the Fe loading capacity was optimized, and then the integrated pollutant removal experiment was conducted, in which TiO 2 doped with Fe as catalyst and H 2 O 2 as oxidant. The results show that under the condition of constant H 2 O 2 /(SO 2 + NO) molar ratio, low concentration of SO 2 can promote the oxidation and removal efficiency of NO, while high concentration of SO 2 can inhibit the removal of NO x . 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 H 2 O 2 /(SO 2 + NO) molar ratio 1.5, space velocity ratio 10,000 h −1 , H 2 O 2 mass fraction 10 wt%, liquid gas ratio 10, pH 10. Correspondingly, NO oxidation efficiency reaches 88%, NO x removal efficiency 85.6%, and SO 2 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.