活性炭混合钢渣烧结烟气脱硫脱硝实验研究

采用混合法用钢渣与活性炭制备混合钢渣活性炭吸附剂,对其进行XRF, BET, SEM和FT-IR等表征,于可编程电加热固定床反应器中进行模拟烧结烟气脱硫脱硝实验,考察反应温度、SO2浓度及NH3]/NO]浓度比、O2含量等因素对混合钢渣活性炭的吸附及催化性能的影响。结果表明,模拟烧结烟气中SO2初始浓度0.06vol%, NO初始浓度0.04vol%, O2含量15vol%及反应温度120℃条件下,最高脱硫脱硝率分别为79%和34%。按浓度比NH3]/NO]=1通入还原剂NH3时,脱硫脱硝率均升高,表明钢渣具有一定催化还原作用。脱硝率随反应温度升高而下降,O2含量提高有利于混合钢渣活性炭对SO2和NO的吸附。掺混钢渣降低了吸附剂的比表面积,但钢渣中含一定量Fe2O3,具有一定催化还原作用,有利于NO吸附。同时,加入钢渣也是对固废资源的合理利用,达到“以废制污”的目的。

Experimental study on desulfurization and denitration of sintering flue gas by activated carbon mixed with steel slag

Absorbent, i.e. activated carbon mixed with steel slag was prepared by mixing method for desulfurization and denitration of sintering flue gas. The samples of absorbent were characterized by XRF, BET, SEM and FT-IR. Experiments of desulfurization and denitration of simulated sintering flue gas were carried out in a programmable electrically heated fixed-bed reactor. The effects of reaction temperature, SO2 concentration, concentration ratio of NH3]/NO] and O2 content were considered. The results showed that the maximum desulfurization and denitration rates were 79% and 34%, respectively, under the conditions of contents of SO2 0.06vol%, NO 0.04vol%, O2 15vol% and at 120℃ of reaction temperature. When NH3 was introduced into the reactor with concentration ratio of NH3]/NO]=1, the desulfurization and denitration rates increased. When NH3 existed, activated carbon mixed with steel slag kept high desulfurization efficiency. The steel slag had a certain catalytic reduction effect. The denitration rate decreased with the increase of reaction temperature. The increase of O2 content can promote the absorption of NO and SO2 by activated carbon mixed with steel slag. Combined with characterization analysis, it was found that the specific surface area of the absorbent reduced by the mixing with steel slag. But activated carbon mixed with steel slag contained a certain amount of Fe2O3 which has a certain catalytic reduction effect and can increase the denitration efficiency. At the same time, the addition of steel slag can also utilize rationally solid waste so as to achieve the purpose of "treatment of pollutants with solid waste".