Plasma-assisted chemical process for NOx control

Plasma-assisted chemical processes have been investigated for the control o f NOx flue gas emissions. Previous results have shown that nonthermal plasm a is able to oxidize NO to NO2, but cannot convert NO2 to N-2 effectively. Rather, part of the NO2 is converted to form N2O and HNO3 (or NO3-). Severa l hydrocarbon additives, catalysts, and water film combined with the nonthe rmal plasma process have been investigated to enhance NOx reduction, but NO x reduction has been limited to the 70% range. As an alternative technology , the plasma-assisted chemical process was developed: plasma reactor to con vert NO to NO2, and the chemical reduction process to convert NO2 to N-2, W ith minimum byproducts. The barrier dielectric packed-bed reactor followed by the chemical reactor was able to achieve nearly 100% NOx decomposition w ith an extremely low power level(14 W/ft(3)/min, 30 J/L, or 40 eV/molecule) and minimum N2O formation. The power consumption becomes 30 J/L, 14 W/ft(3 )/min, or 40 eV, which amounts to $299/t of NO, and the operating cost for the chemical reactor is $1448/t, The total cost is $1747/t, which is at fea st 20 times more economical compared to the conventional NOx control techno logies.