scholarly journals NO<sub><i>x</i></sub> emission trends over Chinese cities estimated from OMI observations during 2005 to 2015

2017 ◽  
Author(s):  
Fei Liu ◽  
Steffen Beirle ◽  
Qiang Zhang ◽  
Ronald J. van der A ◽  
Bo Zheng ◽  
...  
Keyword(s):  
Power Plants ◽  
Emission Control ◽  
Control Measures ◽  
Nox Emissions ◽  
Ozone Monitoring Instrument ◽  
Power Sector ◽  
Emission Data ◽  
Chinese Cities ◽  
Emission Changes ◽  
Urban Emissions

Abstract. Satellite NO2 observations have been widely used to evaluate emission changes. To determine trends in NOx emission over China, we used a method independent of chemical transport models to quantify the NOx emissions from 48 cities and 7 power plants over China, on the basis of Ozone Monitoring Instrument (OMI) NO2 observations during 2005 to 2015. We found that NOx emissions over 48 Chinese cities increased by 52 % from 2005 to 2011 and decreased by 21 % from 2011 to 2015. The decrease since 2011 could be mainly attributed to emission control measures in power sector; while cities with different dominant emission sources (i.e. power, industrial and transportation sectors) showed variable emission decline timelines that corresponded to the schedules for emission control in different sectors. The time series of the derived NOx emissions was consistent with the bottom-up emission inventories for all power plants (r = 0.8 on average), but not for some cities (r = 0.4 on average). The lack of consistency observed for cities was most probably due to the high uncertainty of bottomup urban emissions used in this study, which were derived from downscaling the regional-based emission data to cities by using spatial distribution proxies.

scholarly journals NO<sub><i>x</i></sub> emission trends over Chinese cities estimated from OMI observations during 2005 to 2015

2017 ◽  
Vol 17 (15) ◽  
pp. 9261-9275 ◽  
Author(s):  
Fei Liu ◽  
Steffen Beirle ◽  
Qiang Zhang ◽  
Ronald J. van der A ◽  
Bo Zheng ◽  
...  
Keyword(s):  
Power Plants ◽  
Emission Control ◽  
Control Measures ◽  
Nox Emissions ◽  
Ozone Monitoring Instrument ◽  
Emission Data ◽  
Bottom Up ◽  
Chinese Cities ◽  
Emission Changes ◽  
Urban Emissions

Abstract. Satellite nitrogen dioxide (NO2) observations have been widely used to evaluate emission changes. To determine trends in nitrogen oxides (NOx) emission over China, we used a method independent of chemical transport models to quantify the NOx emissions from 48 cities and seven power plants over China, on the basis of Ozone Monitoring Instrument (OMI) NO2 observations from 2005 to 2015. We found that NOx emissions over 48 Chinese cities increased by 52 % from 2005 to 2011 and decreased by 21 % from 2011 to 2015. The decrease since 2011 could be mainly attributed to emission control measures in power sector; while cities with different dominant emission sources (i.e., power, industrial, and transportation sectors) showed variable emission decline timelines that corresponded to the schedules for emission control in different sectors. The time series of the derived NOx emissions was consistent with the bottom-up emission inventories for all power plants (r = 0. 8 on average), but not for some cities (r = 0. 4 on average). The lack of consistency observed for cities was most probably due to the high uncertainty of bottom-up urban emissions used in this study, which were derived from downscaling the regional-based emission data to city level by using spatial distribution proxies.

scholarly journals Evolution of SO2 and NOx Emissions from Several Large Combustion Plants in Europe during 2005–2015

2020 ◽  
Vol 17 (10) ◽  
pp. 3630 ◽  
Author(s):  
Daniel-Eduard Constantin ◽  
Corina Bocăneala ◽  
Mirela Voiculescu ◽  
Adrian Roşu ◽  
Alexis Merlaud ◽  
...  
Keyword(s):  
Power Plants ◽  
Standard Procedure ◽  
Air Pollutant ◽  
Satellite Observations ◽  
Pollutant Emissions ◽  
Nox Emissions ◽  
The European Union ◽  
Ozone Monitoring Instrument ◽  
Eu Directives ◽  
The Eu

The aim of this paper is to investigate the evolution of SO2 and NOx emissions of ten very large combustion plants (LCPs >500 MW) located in the European Union (EU) during 2005–2015. The evolution of NOx and SO2 emissions were analyzed against the EU Directives in force during 2005–2015. The investigation was performed using space-borne observations and estimated emissions collected from the EEA (European Environment Agency) inventory of air pollutant emissions. The power plants were chosen according to their capacity and emissions, located in various parts of Europe, to give an overall picture of atmospheric pollution with NOx and SO2 associated with the activity of very large LCPs in Europe. Satellite observations from OMI (Ozone Monitoring Instrument) are compared with calculated emissions in order to assess whether satellite observations can be used to monitor air quality, as a standard procedure, by governmental or nongovernmental institutions. Our results show that both space observations and estimated emissions of NOx and SO2 atmospheric content have a descending trend until 2010, complying with the EU Directives. The financial and economic crisis during 2007–2009 played an important role in reducing emissions.

scholarly journals NO<sub>x</sub> emissions in China: historical trends and future perspectives

2013 ◽  
Vol 13 (6) ◽  
pp. 16047-16112 ◽  
Author(s):  
B. Zhao ◽  
S. X. Wang ◽  
J. Y. Xu ◽  
K. Fu ◽  
Z. Klimont ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Emission Reduction ◽  
Power Plants ◽  
Ambient Air ◽  
Control Measures ◽  
Nox Emission ◽  
Nox Emissions ◽  
Emission Scenarios ◽  
Emission Reductions ◽  
Stringent Control

Abstract. Nitrogen oxides (NOx) are key pollutants for the improvement of ambient air quality. Within this study we estimated the historical NOx emissions in China for the period 1995–2010, and calculated future NOx emissions every five years until 2030 under six emission scenarios. Driven by the fast growth of energy consumption, we estimate the NOx emissions in China increased rapidly from 11.0 Mt in 1995 to 26.1 Mt in 2010. Power plants, industry and transportation were major sources of NOx emissions, accounting for 28.4, 34.0, and 25.4% of the total NOx emissions in 2010, respectively. Two energy scenarios, a business as usual scenario (BAU) and an alternative policy scenario (PC), were developed to project future energy consumption. In 2030, total energy consumption is projected to increase by 64 and 27% from 2010 level respectively. Three sets of end-of-pipe pollution control measures, including baseline, progressive, and stringent control case, were developed for each energy scenario, thereby constituting six emission scenarios. By 2030, the total NOx emissions are projected to increase (compared to 2010) by 36% in the baseline while policy cases result in reduction up to 61% in the most ambitious case with stringent control measures. More than a third of the reduction achieved by 2030 between least and most ambitious scenario comes from power sector and more than half is distributed equally between industry and transportation sectors. Selective Catalytic Reduction dominates the NOx emission reductions in power plants, while life style changes, control measures for industrial boilers and cement production are major contributors to reductions in industry. Timely enforcement of legislation on heavy duty vehicles would contribute significantly to NOx emission reductions. About 30% of the NOx emission reduction in 2020, and 40% of the NOx emission reduction in 2030 could be treated as the ancillary benefit of energy conservation. Sensitivity analysis was conducted to explore the impact of key factors on future emissions.

scholarly journals Attributions of meteorological and emission factors to the 2015 winter severe haze pollution episodes in China's Jing-Jin-Ji area

2017 ◽  
Vol 17 (4) ◽  
pp. 2971-2980 ◽  
Author(s):  
Tingting Liu ◽  
Sunling Gong ◽  
Jianjun He ◽  
Meng Yu ◽  
Qifeng Wang ◽  
...  
Keyword(s):  
Air Pollution ◽  
Emission Control ◽  
Northern China ◽  
Air Pollutant ◽  
Control Measures ◽  
Air Pollution Control ◽  
Emission Data ◽  
Haze Pollution ◽  
Stable Conditions ◽  
Emission Control Measures

Abstract. In the 2015 winter month of December, northern China witnessed the most severe air pollution phenomena since the 2013 winter haze events occurred. This triggered the first-ever red alert in the air pollution control history of Beijing, with an instantaneous fine particulate matter (PM2. 5) concentration over 1 mg m−3. Air quality observations reveal large temporal–spatial variations in PM2. 5 concentrations over the Beijing–Tianjin–Hebei (Jing-Jin-Ji) area between 2014 and 2015. Compared to 2014, the PM2. 5 concentrations over the area decreased significantly in all months except November and December of 2015, with an increase of 36 % in December. Analysis shows that the PM2. 5 concentrations are significantly correlated with the local meteorological parameters in the Jing-Jin-Ji area such as the stable conditions, relative humidity (RH), and wind field. A comparison of two month simulations (December 2014 and 2015) with the same emission data was performed to explore and quantify the meteorological impacts on the PM2. 5 over the Jing-Jin-Ji area. Observation and modeling results show that the worsening meteorological conditions are the main reasons behind this unusual increase of air pollutant concentrations and that the emission control measures taken during this period of time have contributed to mitigate the air pollution ( ∼  9 %) in the region. This work provides a scientific insight into the emission control measures vs. the meteorology impacts for the period.

scholarly journals Chemical composition of ambient PM<sub>2.5</sub> over China and relationship to precursor emissions during 2005–2012

2017 ◽  
Author(s):  
Guannan Geng ◽  
Qiang Zhang ◽  
Dan Tong ◽  
Meng Li ◽  
Siwen Wang ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Power Plants ◽  
Emission Inventory ◽  
Nitrate Concentration ◽  
Control Measures ◽  
Nox Emissions ◽  
Sulfate Concentration ◽  
Weighted Mean ◽  
Nitrate Concentrations ◽  
Pm2.5 Concentration

Abstract. We estimated the changes in chemical composition of ambient PM2.5 over China during 2005–2012 using satellite-based aerosol optical depth (AOD) data and the GEOS-Chem chemical transport model, and investigated the driving forces behind the changes by examining the changes in precursor emissions using a bottom-up emission inventory. We found that the national population-weighted mean PM2.5 concentration increased from 63.9 μg/m3 in 2005 to 75.2 μg/m3 in 2007 (+18.19 % per year), and subsequently decreased to 66.9 μg/m3 from 2007 to 2012 (−2.67 % per year), composing a flat trend of population-weighted mean PM2.5 concentration during 2005–2012. Variations in PM2.5 concentrations are mainly driven by the changes in sulfate and nitrate concentrations. Population-weighted mean sulfate concentration increased by 10.72 % from 2005–2006 (from 14.4 μg/m3 to 15.9 μg/m3) and then decreased by 4.30 % per year from 2006–2012, dominating the variations of total PM2.5 concentrations. The decrease of sulfate concentration is partly offset by the increase of nitrate concentration: population-weighted mean nitrate concentration increased by 3.39 % per year during 2005–2012 (from 9.8 μg/m3 to 12.2 μg/m3). The changes in sulfate and nitrate concentrations were in line with the changes in SO2 and NOx emissions during the same period. By examining the emission data from the MEIC emission inventory, we found that the desulfurization regulation enforced around 2005 in power plants was the primary contributor to the SO2 emissions reduction since 2006. In contrast, growth of energy consumption and lack of control measures for NOx resulted in persistent increase in NOx emissions until the installation of denitrification devices on power plants late in 2011, which began to take effect in 2012. The results of this work indicate that the synchronized abatement of emissions for multi-pollutants are necessary for reducing ambient PM2.5 concentrations over China.

scholarly journals The effects of recent control policies on trends in emissions of anthropogenic atmospheric pollutants and CO<sub>2</sub> in China

2012 ◽  
Vol 12 (9) ◽  
pp. 24985-25036 ◽  
Author(s):  
Y. Zhao ◽  
J. Zhang ◽  
C. P. Nielsen
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Radiative Forcing ◽  
Power Plants ◽  
Fine Particles ◽  
Emission Control ◽  
Control Measures ◽  
Atmospheric Pollutants ◽  
Bottom Up ◽  
Industrial Sources

Abstract. To examine the effects of China's national policies of energy conservation and emission control during 2005–2010, inter-annual emission trends of gaseous pollutants, primary aerosols, and CO2 are estimated with a bottom-up framework. The control measures led to improved energy efficiency and/or increased penetration of emission control devices at power plants and other important industrial sources, yielding reduced emission factors for all evaluated species except NOx. The national emissions of anthropogenic SO2, CO, and total primary PM (particulate matter) in 2010 are estimated to have been 89%, 108%, and 86% of those in 2005, respectively, suggesting successful emission control of those species despite fast growth of the economy and energy consumption during the period. The emissions of NOx and CO2, however, are estimated to have increased by 48% and 43%, respectively, indicating that they remain largely determined by the growth of energy use, industrial production, and vehicle populations. Based on application of a Monte-Carlo framework, estimated uncertainties of SO2 and PM emissions increased from 2005 to 2010, resulting mainly from weakly understood average SO2 removal efficiency in flue gas desulfurization (FGD) systems in the power sector, and unclear changes in the penetration levels of dust collectors at industrial sources, respectively. While emission trends determined by bottom-up methods can be generally verified by observations from both ground stations and satellites, clear discrepancies exist for given regions and seasons, indicating a need for more accurate spatial and time distributions of emissions. Limitations of current emission control polices are analyzed based on the estimated emission trends. Compared with control of total PM, there are fewer gains in control of fine particles and carbonaceous aerosols, the PM forms most responsible for damages to public health and effects on radiative forcing. A decrease of alkaline base cations as primary PM that is much faster than that of SO2 may have raised the acidification risks to ecosystems, indicating further control of acid precursors is required. Moreover, with relatively strict controls in developed urban areas, air pollution challenges have been expanding to less-developed neighboring regions. There is a great need in the future for multi-pollutant control strategies that combine recognition of diverse environmental impacts both in urban and rural areas with emission abatement of multiple species in concert.

Prediction and Governance of Mine Gas Emission

2013 ◽  
Vol 419 ◽  
pp. 500-504
Author(s):  
Yi Wen Liu ◽  
Yi Cao ◽  
Lin Zhang ◽  
Ming Chuan Meng
Keyword(s):  
Neural Network ◽  
Coal Mining ◽  
Bp Neural Network ◽  
Emission Control ◽  
Control Measures ◽  
Gas Emission ◽  
Emission Data ◽  
Main Factors ◽  
Mine Gas ◽  
Emission Control Measures

Coal mining gas emission constrained by many factors, considering the eight main factors of gas emission. The first gas emission data are normalized, avoid data overflow to improve the training speed of neural network. Then use BP neural network to predict the amount of mine gas emission, finally proposed gas emission control measures.

scholarly journals NOx emissions in China: historical trends and future perspectives

2013 ◽  
Vol 13 (19) ◽  
pp. 9869-9897 ◽  
Author(s):  
B. Zhao ◽  
S. X. Wang ◽  
H. Liu ◽  
J. Y. Xu ◽  
K. Fu ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Emission Reduction ◽  
Power Plants ◽  
Ambient Air ◽  
Control Measures ◽  
Nox Emission ◽  
Nox Emissions ◽  
Emission Scenarios ◽  
Emission Reductions ◽  
Stringent Control

Abstract. Nitrogen oxides (NOx) are key pollutants for the improvement of ambient air quality. Within this study we estimated the historical NOx emissions in China for the period 1995–2010, and calculated future NOx emissions every five years until 2030 under six emission scenarios. Driven by the fast growth of energy consumption, we estimate the NOx emissions in China increased rapidly from 11.0 Mt in 1995 to 26.1 Mt in 2010. Power plants, industry and transportation were major sources of NOx emissions, accounting for 28.4%, 34.0%, and 25.4% of the total NOx emissions in 2010, respectively. Two energy scenarios, a business as usual scenario (BAU) and an alternative policy scenario (PC), were developed to project future energy consumption. In 2030, total energy consumption is projected to increase by 64% and 27% from 2010 level respectively. Three sets of end-of-pipe pollution control measures, including baseline, progressive, and stringent control case, were developed for each energy scenario, thereby constituting six emission scenarios. By 2030, the total NOx emissions are projected to increase (compared to 2010) by 36% in the baseline while policy cases result in reduction up to 61% in the most ambitious case with stringent control measures. More than a third of the reduction achieved by 2030 between least and most ambitious scenario comes from power sector, and more than half is distributed equally between industry and transportation sectors. Selective catalytic reduction dominates the NOx emission reductions in power plants, while life style changes, control measures for industrial boilers and cement production are major contributors to reductions in industry. Timely enforcement of legislation on heavy-duty vehicles would contribute significantly to NOx emission reductions. About 30% of the NOx emission reduction in 2020 and 40% of the NOx emission reduction in 2030 could be treated as the ancillary benefit of energy conservation. Sensitivity analysis was conducted to explore the impact of key factors on future emissions.

scholarly journals The effects of recent control policies on trends in emissions of anthropogenic atmospheric pollutants and CO<sub>2</sub> in China

2013 ◽  
Vol 13 (2) ◽  
pp. 487-508 ◽  
Author(s):  
Y. Zhao ◽  
J. Zhang ◽  
C. P. Nielsen
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
Radiative Forcing ◽  
Power Plants ◽  
Fine Particles ◽  
Emission Control ◽  
Control Measures ◽  
Atmospheric Pollutants ◽  
Bottom Up ◽  
Industrial Sources

Abstract. To examine the effects of China's national policies of energy conservation and emission control during 2005–2010, inter-annual emission trends of gaseous pollutants, primary aerosols, and CO2 are estimated with a bottom-up framework. The control measures led to improved energy efficiency and/or increased penetration of emission control devices at power plants and other important industrial sources, yielding reduced emission factors for all evaluated species except NOx. The national emissions of anthropogenic SO2, CO, and total primary PM (particulate matter) in 2010 are estimated to have been 89%, 108%, and 87% of those in 2005, respectively, suggesting successful emission control of those species despite fast growth of the economy and energy consumption during the period. The emissions of NOx and CO2, however, are estimated to have increased by 47% and 43%, respectively, indicating that they remain largely determined by the growth of energy use, industrial production, and vehicle populations. Based on application of a Monte-Carlo framework, estimated uncertainties of SO2 and PM emissions increased from 2005 to 2010, resulting mainly from poorly understood average SO2 removal efficiency in flue gas desulfurization (FGD) systems in the power sector, and unclear changes in the penetration levels of dust collectors at industrial sources, respectively. While emission trends determined by bottom-up methods can be generally verified by observations from both ground stations and satellites, clear discrepancies exist for given regions and seasons, indicating a need for more accurate spatial and time distributions of emissions. Limitations of current emission control polices are analyzed based on the estimated emission trends. Compared with control of total PM, there are fewer gains in control of fine particles and carbonaceous aerosols, the PM components most responsible for damages to public health and effects on radiative forcing. A much faster decrease of alkaline base cations in primary PM than that of SO2 may have raised the acidification risks to ecosystems, indicating further control of acid precursors is required. Moreover, with relatively strict controls in developed urban areas, air pollution challenges have been expanding to less-developed neighboring regions. There is a great need in the future for multi-pollutant control strategies that combine recognition of diverse environmental impacts both in urban and rural areas with emission abatement of multiple species in concert.

scholarly journals Chemical composition of ambient PM<sub>2. 5</sub> over China and relationship to precursor emissions during 2005–2012

2017 ◽  
Vol 17 (14) ◽  
pp. 9187-9203 ◽  
Author(s):  
Guannan Geng ◽  
Qiang Zhang ◽  
Dan Tong ◽  
Meng Li ◽  
Yixuan Zheng ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Power Plants ◽  
Emission Inventory ◽  
Driving Forces ◽  
Measurement Data ◽  
Control Measures ◽  
Nox Emissions ◽  
Weighted Mean ◽  
National Population

Abstract. In this work, we presented the characteristics of PM2. 5 chemical composition over China for the period of 2005–2012 by synthesis of in situ measurement data collected from literatures and satellite-based estimates using aerosol optical depth (AOD) data and the GEOS-Chem chemical transport model. We revealed the spatiotemporal variations in PM2. 5 composition during 2005–2012 and investigated the driving forces behind the variations by examining the changes in precursor emissions using a bottom-up emission inventory. Both in situ observations and satellite-based estimates identified that secondary inorganic aerosols (i.e., sulfate, nitrate, and ammonium; SNA) ranked as the highest fraction of dust-free PM2. 5 concentrations, followed by organic matter (OM) and black carbon (BC). For instance, satellite-based estimates found that SNA, OM, and BC contributed to 59, 33, and 8 %, respectively, of national population-weighted mean dust-free PM2. 5 concentrations during 2005–2012. National population-weighted mean PM2. 5 concentration increased from 63.9 µg m−3 in 2005 to 75.2 µg m−3 in 2007 and subsequently decreased to 66.9 µg m−3 from 2007 to 2012. Variations in PM2. 5 concentrations are mainly driven by the decrease in sulfate and the increase in nitrate. Population-weighted mean sulfate concentration decreased by 2.4 % yr−1 during 2005–2012 (from 14.4 to 12.9 µg m−3), while population-weighted mean nitrate concentration increased by 3.4 % yr−1 during 2005–2012 (from 9.8 to 12.2 µg m−3), largely offsetting the decrease in sulfate concentrations. By examining the emission data from the Multi-resolution Emission Inventory for China (MEIC), we found that the changes in sulfate and nitrate concentrations were in line with the decrease in SO2 emissions and the increase in NOx emissions during the same period. The desulfurization regulation in power plants enforced around 2005 has been the primary contributor to the SO2 emission reduction since 2006. In contrast, growth of energy consumption and lack of control measures for NOx resulted in a persistent increase in NOx emissions until the installation of denitrification devices on power plants late in 2011, which began to take effect in 2012. The results of this work indicate that the synchronized abatement of emissions for multipollutants is necessary for reducing ambient PM2. 5 concentrations over China.

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