Study On Green Technology Of Desulfurization And Denitrification

Flue gas contains a lot of nitrogen oxides and sulfur oxides,which can cause acid rain,acid mist and smog,and seriously hinder the daily work of human life.The traditional process of flue gas desulfurization and denitrification has the shortage of complication,large area occupied,equipment bulkness and high energy consumption.Therefore,it is necessary to find a suitable process to remove the sulfur oxides and nitrogen oxides in the flue gas.In our study,NO and SO2,which are not soluable in water,are oxidized to NO2 and SO3 by ozone and then absorbed by water so as to be removed from the flue gas.The design capacity is 1000m3/h flue gas.In this paper,process simulation and optimization is conducted using Aspen Plus V7.3.NRTL method is used as the physical property method according to the nature of components.Based on the analysis of the influence of the reactor temperature,the flow rate and temperature of the absbent,the number of the absorption tower on the removal efficiency,and the thermodynamic and hydraulics analysis,the optimum operating conditions are obtained as follow,the feed temperature 150?,n(O3)/n(NO)= 2,the ozone generator temperature 25?,the oxidation reactor temperature 160?,the absorption tower 10 stages and operated at 25? and 0.1MPa,water absorbent flowrate 150kmol/h.According to the simulation results,the equipments such as pumps,heat exchangers,absorption tower and compressors used are designed.The removal efficiency of SOx and NOx can reach 97.5% and 92% under the optimal conditions,which can meet the design requirements.Then the flow field of the ozone reactor was simulated and optimized using Fluent 17.0.The simulation results show that the ozone reactor designed can meet the design requirements.Finally,the technical and economic analysis of this desulfurization and denitrification process are carried out.The results show that the process is technically and economically feasible.