Numerical simulation of de- N Ox performance by repetitive pulsed discharge when added with hydrocarbons such as ethylene

Emission regulations are gradually being tightened recently to prevent further air pollution. Cost-effective and efficient technologies must be developed to process the N Ox generated in the combustion of fossil fuels. One of the candidate technologies to process N Ox is the denitrification of flue gas by pulsed corona discharge, which has been demonstrated experimentally to show high de- N Ox performance. However, the optimization of operation conditions and the appropriate understanding of the de- N Ox process still remain to be clarified. Therefore, following our previous study on ammonia injection, we have simulated in the present study the de- N Ox process to which hydrocarbons such as ethylene have been added to provide guidelines on its proper operation conditions and its main reaction paths to remove N Ox. The simulated results show that the removal efficiency in a case of ethylene addition becomes lower than for ammonia addition, but the de- N Ox energy consumption rate becomes lower than for ammonia injection. However, with ethylene injection the production of the pollutant, formaldehyde, limits the allowable amount of injected ethylene. The de- N Ox performance is better with propylene than ethylene injection because propylene reacts with the OH radical more than ethylene to oxide N Ox. However, formaldehyde is also produced in the case of propylene injection, limiting the allowable amount of injected propylene. The de- N Ox performance is also assessed in a case where HN O2 is considered as Nx Oy.