The Theoretical Study Of The Desorption Of SO₂and No_x Of The Flue Gas On The Copper-based Desulfurizer

SO2and the NOxare the most common air pollutants found in burning thefossil, and are greatly harmful to the environment and human health. Therefore,controlling their pollutant has been received much attention. In order to getmore detail information about the dissociation mechanism of SO2and NOxonCu2O(111) surface and give direction to the discovery of the desulfurizers, westudy the dissociation of SO2on the different Cu2O(111) surfaces, thesimultaneous reduction of NOxand SO2on Cu2O(111) surface and theregeneration process of vulcanized Cu2O(111) surface with the densityfunctional theory together with the periodic slab mode. The main conclusionsobtained from this work are summarized as follows:(1) The dissociation barrier of SO2on Cu2O(111) surface is very high,318.384kJ mol-1, which demonstrates that the perfect Cu2O(111) surface hasweak activity toward the SO2dissociation. However, the presence ofoxygen-vacancy, H pre-covered and Cu particle deposition signi cantly reducethe dissociation barrier,80.175,133.046and56.340kJ mol-1, respectively. The present results indicate that the SO2dissociation are greatly enhanced with thepresence of the oxygen-vacancy, H pre-covered and Cu particle deposition onthe Cu2O(111) surface.(2) The NOxin the flue gases have obviously impact on the SO2dissociation on Cu2O(111) surface. On Cu2O(111) surface, the NO2will interactdirectly with SO2to produce NO and SO3, and then the produced NO willinteracte with SO2together with the original NO. When NO interacts with SO2,it will produce the N2O and O in the dimer method firstly, and then the N2Odissociate to produce the N2and O. At last, the SO2is oxidized to SO3by thedissociated O. The above steps have the activation barrier of121.372,101.593,139.992and121.372kJ mol1, respectively. Compared with the dissociationbarriers of SO2dissociation on the perfect Cu2O(111) surface, the lowdissociation barriers of the above steps demonstrate that the NOxhave thepositive effect on the SO2dissociation on the Cu2O(111) surface.(3) Our study results suggest that when the H2is used as the regenerationatmosphere, the rate limite step has the activation barrier of180.843kJ mol-1which is obviously lower than that of the O2as the regeneration atmosphere,290.984kJ mol-1. The above results demonstrate that can use the hightemperature H2replace the high temperature O2as the regeneration atmospherewhen regeneration the desulfurizers.