Research On The Optimization Method Of Urban Air Pollution Control And Its Application In Cheng-Yu District

To improve the quality of atmospheric environment involves multiple approaches and measures.Obtaining control measures under the constraints of environmental quality objectives,with optimal reduction cost,is the key to achieving continuous improvement of atmospheric environment and coordination of economic and social development.In this research,an optimization model suitable for urban air pollution control,integrating accuracy and operability,was constructed.The optimization model was applied in the power industry and industry in Cheng-Yu District.The main conclusions are as follows:1 The optimization model was based on the optimization method and considered two types of emission reduction approaches,including the clean energy substitution and end-of-pipe technologies.A single-objective non-linear air pollution control optimization model with the lowest cost as the goal was established.The objective function is the minimum total cost of emission reduction,with the theoretical cost function of different approaches and industries.Constraints include the emission of air pollutants,the technology penetration rate,the reduction rate,and the resource constraints of clean energy substitution.2 The optimization model was applied to reduce the emissions of SO₂、NO_x and PM_2.5 in the power industry and industry in Cheng-Yu District in 2035.A reduction costs database and cost function for the power industry and industry in Cheng-Yu District were established,and two scenarios for air quality constraints were designed.There are two optimization methods in different scenarios was set up,the one considered both of the clean energy substitution and end-of-pipe technologies,the other one only considered the optimization of end-of-pipe technologies.Fifty decision variables,which include the penetration rate of clean energy,the reduction rate and penetration rate of end-of-pipe technologies,and localized optimization model under different scenarios and different optimization methods were set for Cheng-Yu Distric.The genetic algorithm was used in MATLAB to solve the optimization model.3 Under the premise of total control,it may be more economical to consider only end-of-pipe technologies.However,with the same air quality constraints in this research,the scenario that considered the clean energy substitution reduced more pollutants than the scenario that only considers the end treatment technology.4 Under the condition of no natural gas power generation,the proportion of hydropower generation in Cheng-Yu Distric has increased,and the improvement of air quality constraints has driven the proportion of hydropower generation to increase significantly.The emission reduction achieved by clean energy substitution in the power industry in Cheng-Yu Distric is mainly derived from the contribution of Sichuan region.The amount of SO₂ reduced by hydropower generation is much higher than the reduction of NO_x and PM_2.5.The cost of hydropower in Sichuan region is much higher than the total cost of coal-fired power generation and end-of-pipe technologies,while it’s opposite in Chongqing region.5 The reduction of PM_2.5 is the largest while the reduction of SO₂ is the smallest among the pollutants reduced by the end-of-pipe technologies in Cheng-Yu Distric.Compared with the baseline year,the overall desulfurization rate of the power industry and the industry has increased slightly,and the overall denitrification rate has increased significantly,while the overall dust removal rate of some industries have increased.The sintering sector is the main contributor to SO₂ reduction and the cost reduction,the cement sector accounts for over 99%of the industrial denitrification and the denitrification cost.The glass sector is the main industry to reduce PM_2.5,accounting for more than 50%and the dust removal cost of the industry is mainly in the glass sector,cement sector and steel sector.