Study On Lncreasing Desulfuration Efficiency Of Flue Gas Using Pulsed Discharge Plasma

In order to increase the desulphurization efficiency of the flue gas during the pulsed corona discharge process, and improve the effects that water & ammonia (NHa) on the desulphurization, water vapor activation with a corona discharges was proposed. The thought was put into practice by the addition of an activation equipment of water vapor at the front part of the pulsed discharge reactor. This equipment is based on the principle of DC corona discharge. Water vapor is ejected out through the discharge electrode of the Activation Equipment, and injected into the pulsed discharge reactor. At the same time, the ammonia can also be treated activated in this equipment.The discharge characteristic of the activation electrode was studied, which induced a design of activation electrode for water and ammonia. The effect of the activation on the removal rate of SO2 was studied, when water and ammonia was employed separately, then simultaneously and the simultaneous activation of water & NH3 determined. Ions and radicals produced during the corona discharge was measured and diagnosed by the molecular beam mass spectrometer and optical emission spectroscopy, the reaction dynamics of the pulsed discharge process was analyzed. The main achievements and results are as follows:1. The characteristics of the corona discharge and the influence factors were studied with the addition of the water vapor and NH3 which shown that the discharge currents increased with the increase of the applied voltage. Under the condition of the same voltage the discharge current with water vapor and NH3 is smaller than that without the water vapor and NH3. However, the flow rate of water vapor and NHs give little influence to the current. The bias voltage and falling part voltage of the waveform increase with the addition of water vapor and NH3 while peak voltage of the current waveform is lowered. The design methods of the water & NH3 activation equipment is: (1) Multi-needle electrode configuration was selected and the needles are paralleled to the plate electrodes. (2) Positive DC power supply was choosed.2. Researched the influence of activation of water vapor on S02 removal rate, the conclusions were drawn the activation of water vapor with corona discharge play a certain part for the removal of SO2 in the simulated flue gas, S02 removal rate increases with the increase of both the applied DC voltage and the water vapor injected into the reactor; SO2 removal rate of DC corona activation is better than that of the pulsed corona, that is because the electric field of DC power can always act on the water vapor, while each nanosecond pulse electricfield can for only a short period of time (<1 s), therefore, more active radicals are produced during DC corona and SO2 removal rate is higher. The employing activation of water vapor with DC corona discharge into the pulsed discharge plasmas desulphurization technologies can obviously improve the S02 removal rate. Research results show that corona discharge water vapor activation technique is effective and practical.3. Studies of the NH3 activation with for corona discharge S02 removal show that activation increases the SO2 removal rate, and the desulphation rate increases with the' increase of the activating voltage, in addition, NH3/S02 mol rate also influences the SO2 removal rate. The adding the NH3 activation onto the desulphation techniques with pulsed discharge plasma, can increase the S02 removal rate, and reduce the NH3 emission. This justified the NH3 corona discharge activation technique is effective.4. Researches of the simultaneous activation of water vapor and NH3 for the removal of S02 show that S02 removal rate of the simultaneous activation is better than that of activation water vapor or NH3 separately. The higher S02 removal rate indicates that the simultaneous activation is effective to improve the S02 removal rate of the pulsed discharge plasma. The design of the simultaneous activating equipment is given.5. The molecular beam mass spectrometer and optical emissio...