Combined fast selective reduction using Mn-based catalysts and nonthermal plasma for NOx removal

Chen, JunXiang; Pan, KuanLun; Yu, ShengJen; Yen, ShawYi; Chang, MooBeen

Combined fast selective reduction using Mn-based catalysts and nonthermal plasma for NOx removal

2017

Chen, JunXiang | Pan, KuanLun | Yu, ShengJen | Yen, ShawYi | Chang, MooBeen

In this study, the concept of fast SCR for NO reduction with NH₃ as reducing agent is realized via the combination of nonthermal plasma (NTP) with Mn-based catalyst. Experimental results indicate that 10% wt. Mn-Ce-Ni/TiO₂ possesses better physical and chemical properties of surface, resulting in higher NO removal efficiency if compared with 10% wt. Mn-Ce/TiO₂ and 10% wt. Mn-Ce-Cu/TiO₂. Mn-Ce-Ni/TiO₂ of 10% wt. achieves 100% NOₓ conversion at 150 °C, while 10% wt. Mn-Ce/TiO₂ and 10% wt. Mn-Ce-Cu/TiO₂ need to be operated at a temperature above 200 °C for 100% NOₓ conversion. However, NO conversion achieved with 10% wt. Mn-Ce-Ni/TiO₂ is significantly reduced as H₂O₍g₎ and SO₂ are introduced into the SCR system simultaneously. Further, two-stage system (SCR with DBD) is compared with the catalyst-alone for NOₓ conversion and N₂ selectivity. The results indicate that 100% NOₓ conversion can be achieved with two-stage system at 100 °C, while N₂ selectivity reaches 80%. Importantly, NOₓ conversion achieved with two-stage system could maintain >95% in the presence of C₂H₄, CO, SO₂, and H₂O₍g₎, indicating that two-stage system has better tolerance for complicated gas composition. Overall, this study demonstrates that combining NTP with Mn-based catalyst is effective in reducing NOₓ emission at a low temperature (≤200 °C) and has good potential for industrial application.

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