Removal Of SO₂ And NO_x By A Pilot Plant Of Pulsed Corona Combined With In Situ Absorption

The influences on atmospheric environment of emissions of SO₂ and NOx caused by coal combustion become more and more serious. PPCP (pulsed corona induced plasma chemical process) has been regarded as a new technology for flue gas desulfurization and denitrification by many researchers. In this paper, pulsed corona combined with in situ absorption was proposed to achieve simultaneously desulfurization and denitrification.In the reactor, a plate-wire-plate combination is devised for generating pulsed corona and then alkaline absorbent slurry were introduced into the reactor by a continuous band conveying system to capture the gaseous reaction products. The effects of pulse peak voltage, pulse frequency, absorbent types, gas initial concentration and flue gas flow rate on the removal of SO₂ and NO were experimentally investigated. It was found that both SO₂ and NO could be effectively removed by corona combined with in situ alkali absorption in the reactor.It was found that about 60% of inlet SO₂ was removed by the Ca(OH)₂ absorbent in the reactor without corona discharge. The removal of SO₂ increased from 56% to 75% with the increase of input pulse peak voltage to 30 kV.It was also found the removals of NO increased with increasing of pulse peak voltage. About 40% removal of NO was reached by pulsed corona discharge with in situ Ca(OH)₂ absorption at 30 kV. The outlet concentration of NO₂ was largely decreased with the presence of Ca(OH)₂ sorbent in the reactor.When both SO₂ and NO were added in the simulated flue gas simultaneously, about 98% of SO₂ and 68% of NO in the gas stream were removed by in situ Ca(OH)₂ absorption combined with a peak voltage 30 kV. It was found with the increase in the concentration of SO₂, the removal of NO decreased.The removals of SO₂ and NO using CaCO₃, ZnO or MgO as absorbents were also investigated.