Simultaneous desulfurization and denitrification of flue gas by catalytic ozonation over Ce–Ti catalyst

Abstract

A novel oxidation-removal process for simultaneous removal of NOX and SO2 was developed, which utilized the catalytic ozonation over Ce–Ti catalyst and assisted with a glass made ammonia-based washing tower. Compared with conventional flue gas treatment, the present method acquires non-secondary pollution, minimal waste production and low operating costs. The main byproducts, ammonia sulfate and nitrate, are important fertilizers and industrially raw materials. A maximum removal of 95% for NOX and nearly complete SO2 removal were obtained with the assistance of washing tower under the following experimental conditions: O3 concentration, 8.5mg·L−1; flow of oxidant mixtures, 100mL·min−1; simulated flue gas temperature, 120°C; H2O flow, 2.4mL·min−1; and total gas flow, 400mL·min−1. The reaction mechanisms are discussed, and the final oxidation products are characterized. The experimental results show that the OH radicals from catalytic ozonation have an oxidation-removal effect of NOX and SO2. The multipollutant capacity of the washing tower is largely enhanced with the Ce–Ti catalyst. And the present method performs better stability with the assistance of the washing tower.