Simultaneous removal of NO_x and SO₂ from glass furnace flue gas by ozone oxidation and spray tower

The experiment on simultaneous removal of NO_x and SO₂ from glass furnace flue gas by ozone oxidation and spray tower was carried out. The experimental results show that the concentration of the sodium hydroxide as the spray solution has less effect on NO_x removal efficiency when pH is above 10, but SO₂ in the flue gas greatly enhances the NO_x removal. The NO_x removal efficiency reaches 70% and the SO₂ removal efficiency remains above 99% as the concentration of sodium hydroxide (NaOH) is 0.5% and the O₃/NO mol ratio is 1.6. When sodium sulfide (Na₂S) is added into the spray solution, the NO_x removal efficiency is improved and increases with the concentration of Na₂S. During this process, SO₂ has no obvious influence on the NO_x removal; the NO_x removal efficiency reaches 70% and the SO₂ removal efficiency remains above 95% as the concentration of NaOH and Na₂S is 0.5% and 0.6%, respectively, and the O₃/NO mol ratio is 1.2. Long-running experiments (60 min) indicate that NO is transformed into NO₂^- in the solution and the NO_x removal efficiency does not change with the pH value of the spray solution.