Study On Temporal-spatial Characteristics And Abatement Potential Of Air Pollutants Emission From Industrial Boilers Of China

The prevention and control of industrial boiler pollution have been regarded as the key step for further strengthening the prevention and control of air pollution in China.In this study,based on technology diffusion theory and measured data of pollutant emission from industrial boilers,the database of the atmospheric pollutants emission factor of industrial boilers in China had been established for the long term for the first time.And then,the atmospheric pollutant emission inventories of coal-fired industrial boilers in China from 1980 to 2017 and gas-fired industrial boilers in China from 1995 to 2017 were established for the first time.Taking 2016 as the base year and the existing economic development and policy as the background,the scenarios of the emission control of industrial boilers in 2020 and 2030 were constructed,respectively.Based on the CMAQ model,the environmental benefits of the emission reduction of industrial boilers in Beijing in typical months in winter were analyzed under the future emission control scenarios.Finally,combined with the temporal-spatial characteristics,and the future abatement potential of emission from industrial boilers in China,the countermeasures and suggestions for emission control strategy of industrial boilers in China were put forward.The main conclusions are as follows:?1?Emission standard revision has a significant effect on the change of emission factors.It was found that the change of PM and SO₂ emission factor is divided into three stages.From 1980 to2000,the average annual decrease of PM and SO₂ emission factor were 2.7%and 0.7%,respectively;from 2001 to 2004,the average annual decrease of PM and SO₂ emission factor were 7.4%and1.8%,respectively;in 2016,PM and SO₂ emission factor decreased to 5.7 kg/t and 8.4 kg/t,respectively.Although the NOx emission control of industrial boilers started late,the NOx emission factor of coal-fired industrial boilers began to decrease to 2.90 kg in 2016 and was 5%lower than2014.The revision time of emission standard coincides with the change node of emission factor variation.?2?This study took the nation and typical cities as the research objects,and the temporal-spatial characteristics and the environmental impact of industrial boilers were studied in terms of regional and urban scales.For coal-fired industrial boilers,the emission of PM,SO₂ and NOx were estimated at 5.43,6.99 and 2.55 million tons,respectively.PM firstly fluctuated and increased in 2008,then decreased year by year;SO₂ and NOx emissions decreased significantly after 2012.In terms of the coal-fired boiler emission spatial distribution,emissions were mainly concentrated in North,Northeast and East China.For gas-fired industrial boilers,the average annual growth rate of NOx emissions from 1995 to 2016 was 42%,and by 2016 the NOx emissions increased to 56000 tons,mainly in the Beijing-Tianjin-Hebei region.Moreover,based on the unit-based emission inventory in 2015 and the simulation results of CMAQ air quality model,the SO₂ and PM emissions of industrial boilers in Beijing were mainly distributed in suburban areas in 2015,while NOx was more concentrated in urban areas.Taking January 2015 as the simulation period,the contribution rates of industrial boilers to PM_2.5,SO₂ and NO₂ in Beijing were 7.1%,9.5%and 4.3%respectively.?3?Taking 2016 as the base year,under the current policy background,the pollutants emission from coal-fired industrial boilers in various provinces of China in 2020 and 2030 were determined by scenario analysis.As shown by the results,compared with 2016,emissions of PM,SO₂ and NOx from coal-fired industrial boilers in China will be reduced by 61%,87%and 56%in 2020 and will be reduced by 95%,94%and 71%in 2030,respectively.Central China and Southwest China have gradually become the regions with the highest emissions of PM and SO₂ from coal-fired industrial boilers,while East China was still the region with the highest emissions of NOx from coal-fired industrial boilers,although it has a strong potential for emission reduction.Taking Beijing as the typical city and using January as the simulation period,the atmospheric environmental concentration reduction rates of PM_2.5 and SO₂ under the emission control scenarios in 2020 and2030,obtained by using the CMAQ model,are 7.1%and 9.5%,respectively;NO₂ under the emission control scenarios in 2020 and 2030,obtained by using CMAQ model,are 4.47%and4.65%,respectively.