The Simultaneous Desulfurization And Denitration From Sintering Flue Gas By Ammonia-complexing Agent And Complexing Agent Regeneration

NO,SO₂ and inhalation particulate have a huge negative impact on human health.In order to control haze,a series of NO and SO2 emissions related laws or regulations have been drawn.Ammonia desulfurization is regarded as the optimum method of removing SO2 form the sintering flue gas because of high efficiency,high value of by-product as well as denitration.At the same time,the denitration by complexing agent has been widely studied due to its higher efficiency and lower operating costs.The simultaneous desulfurization and denitration by ammonia-complexing agent method can be achieved in an reactor,which has the advantages of low operating cost and high value of by-product.However,there is still some bottleneck such as the quality of by-product and the regeneration of complexing agent.In this paper,the regeneration method of complexing agent after denitration was developed in a pilot scale reactor.At the same time,the optimum parameters of ammonia-complexing agent were also investigated.On the basis of experimental results,the materials balance was calculated and the economic evaluation was carried out.The experimental results showed that the highest desulfurization and denitrification efficiencies were 99% and 75% respectively when iron powder was used as regeneration agent.The desulfurization efficiency of 97% and the denitrification efficiency of 46% were obtained in the case of coke powder.However,the highest desulfurization and denitrification efficiencies were only 80% and 20% after the complexant regenerated by biformyl.Hence,it could be drawn that the optimal regeneration agent was iron powder.Furthermore,the regeneration by iron powder was also studied in a pilot scale system,the efficiency of desulfurization and denitration were stable at 100% and 60%.Moreover,the deferrization was also considered and the denitration efficiency can keep at 43 61%.The concentration of iron ion and soudium ion were stable at 0.06mol/L and 0.15mol/L.Finally,the pilot study of simultaneously desulfurization and denitration by ammonia-complexing agent indicated the desulfurization efficiency had been stable at around 99% before and after the regeneration;However,the denitration efficiency decreases from 69% to 50% at the first 80 minutes.After the precipitation method was taken and 10% complexing agent was added to the reactor,the denitration efficiency was stabilized at 42% from 120 min to 240 min.According to material balance,the economic analysis was carried out and the cost of removing 1kgNOand 1kgSO₂ was6.75 yuan.