[Removal of NOx by nonthermal plasma combined with CuO catalyst or in situ Ca(OH)2 absorption]

The removals of NO by a wire-in-tube nonthermal plasma reactor combined with catalysis or in situ chemical absorption were investigated. Experimental results show that the plasma reduction of NO was much enhanced by the CuO catalyst in the reactor. On the other hand, for the catalytic reduction of NO, the reaction temperature was effectively decreased by the pulsed corona discharge. A NO reduction of 100% by the plasma reactor combined with CuO catalyst was achieved under the operation condition of inlet NO concentration 719 mg/m3, 1% CO, pulse voltage 18 kV and reaction temperature 473 K. For plasma combined with in situ absorption, it was found that NO removal was much higher than by the reactor without Ca(OH)2 sorbent. It was demonstrated that in situ absorption of NO oxidation products of NO2 and/or NO3 by Ca(OH)2 was responsible for the promotion of NO removal. NO removal of 100% was achieved for 1050 mg/m3 NO in a gas mixture of 2% O2 and 98% N2 with a pulse voltage of 18 kV.