摘要
Flue gas cleaning in discharge plasma process has been studied intensivelyand we have tried to remove the NO_x and SO_2 using the wet-type plasma reactor. In this system, NOis oxidized to NO_2 and absorbed as NO_3^-, and SO_2 is absorbed as SO_3^(2-) and oxidized in theliquid to SO_4^(2-). But the concentration of NO_3^- was saturated and the absorption of NO_x andSO_2 was inhibited. Then, the reduction of NO_3^- in the liquid is required. We examined thereductive reaction of NO_3^- to NH_4^+ using discharge above the liquid surface then the pH value ofthe liquid was changed to alkaline slightly. When the Fe plate was used as a ground electrode inthe liquid, NH_4^+ was generated. Then, the relation between the generation of NH_4^+ and Fe ions(Fe^(2+) and Fe^(3+)) was studied. When Fe^(2+) was presented in the liquid, NH_4^+ was generatedand Fe^(2+) was oxidized to Fe^(3+). Fe^(2+) is required to generate NH_4^+ from NO_3^-. When NH_4^+was generated from NO_3^-, both the calculated pH value from NH_4^+ concentration and the measuredpH value indicated a similar value. From these results, the discharge above the liquid surface waseffective to convert NO_3^- to NH_4^+ and the reductive reaction leads to more absorption of NO_3^-.These results showed that the wet-type plasma reactor is effective for NO_x and SO_2 removalsystem.
Flue gas cleaning in discharge plasma process has been studied intensivelyand we have tried to remove the NO_x and SO_2 using the wet-type plasma reactor. In this system, NOis oxidized to NO_2 and absorbed as NO_3^-, and SO_2 is absorbed as SO_3^(2-) and oxidized in theliquid to SO_4^(2-). But the concentration of NO_3^- was saturated and the absorption of NO_x andSO_2 was inhibited. Then, the reduction of NO_3^- in the liquid is required. We examined thereductive reaction of NO_3^- to NH_4^+ using discharge above the liquid surface then the pH value ofthe liquid was changed to alkaline slightly. When the Fe plate was used as a ground electrode inthe liquid, NH_4^+ was generated. Then, the relation between the generation of NH_4^+ and Fe ions(Fe^(2+) and Fe^(3+)) was studied. When Fe^(2+) was presented in the liquid, NH_4^+ was generatedand Fe^(2+) was oxidized to Fe^(3+). Fe^(2+) is required to generate NH_4^+ from NO_3^-. When NH_4^+was generated from NO_3^-, both the calculated pH value from NH_4^+ concentration and the measuredpH value indicated a similar value. From these results, the discharge above the liquid surface waseffective to convert NO_3^- to NH_4^+ and the reductive reaction leads to more absorption of NO_3^-.These results showed that the wet-type plasma reactor is effective for NO_x and SO_2 removalsystem.
