High concentration NOx, SOx and particulate removal system using the plasma-chemical hybrid process

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The objective of the research is to remove high concentration (1,000〜2,000ppm) NOx and SOx at high flue gas gas temperature (>250℃), and also to remove particulate matters (PM) from diesel engine and boiler emission. The adsorption and plasma hybrid process were employed to control the diesel emission and the plasma chemical hybrid process was employed to control the boiler emission. In the dry process for diesel emission control, the adsorbent using molecular shieve (MS-13X) was used to adsorb NOx effectively, and adsorbed NOx were desorbed and regenerated using N2 by means of heat in the diesel emission system. The desorbed high concentrated NOx were totally reduced by the nonthermal plasma to form N_2 and O_2. Since the moisture content in the diesel engine was affected by NOx adsorption process, the use of silicate was investigated. As the results, the use of silicate was to place upstream of the adsorbent.(or high temperature side). Other hydrophobic adsorbent such as Mn based ads … More orbent was also found to be extremely suited for NOx adsorption. We also found that NOx desorption by heat took place effectively even at 120℃ and NOx concentration was increased with repetitive thermal desorption and reached a constant desorption efficiency beyond 7 repetitive desorption process. As far as PM is concerned, PM was trapped with the conventional diesel particulate filter (DPF) and incinerated with either NO_2 at the gas temperature of 250℃ and O_3.even at the room temperature.On the other hand, the plasma chemical process used for boiler emission control, ozpnizer was used to oxidize NO to form NO_2 in the gas stream and formed NO_2 was reduced by the chemical scrubber using Na_2SO_3 solution to achieve N_2 and water soluble and nontoxic Na_2SO_4. The required amount of O_3 was approximately one stoichiometric of NO concentration in the gas stream. The NOx reduction was affected by CO_2 and O_2 concentrations in the gas stream and the optimization study was performed, resulting that more that 85% of NOx reduction was achieved throughout the experiments. Less