Cu-SAPO-34/cordierite catalysts were prepared via one-step hydrothermal synthesis method and their performances to remove NO x from the diesel vehicle exhaust were evaluated. The morphology, structure, Cu content and ...Cu-SAPO-34/cordierite catalysts were prepared via one-step hydrothermal synthesis method and their performances to remove NO x from the diesel vehicle exhaust were evaluated. The morphology, structure, Cu content and valence state were characterized by SEM, XRD, ICP and XPS, respectively. The experimental results show the active component Cu of the catalysts via in situ synthesis could significantly improve the selective catalytic reduction （SCR） activities of NOx and the optimal Cu content is in the range of 0.30%-0.40%（mass fraction）. No N 2 O is detected by gas chromatograph （GC） during the evaluation process, which implies that NOx is almost entirely converted to N2 over Cu-SAPO-34/cordierite catalyst. The conversion rate of NOx to N2 by NH3 over catalyst could almost be up to 100%in the temperature range of 300-670 ℃with a space velocity of 12000 h-1 and it is still more than 60% at 300-620 ℃ under 36000 h-1. The catalysts also show the good hydrothermal and chemical stability at the atmosphere with H 2 O.展开更多
The transportation sector is responsible for 25% of the total Carbon dioxide (CO2) emissions, whereas 60.6% of this sector represents small and medium passenger cars. However, as noted by the European Union Long-term ...The transportation sector is responsible for 25% of the total Carbon dioxide (CO2) emissions, whereas 60.6% of this sector represents small and medium passenger cars. However, as noted by the European Union Long-term strategy, there are two ways to reduce the amount of CO2 emissions in the transportation sector. The first way is characterized by creating more efficient vehicles. In contrast, the second way is characterized by changing the fuel used. The current study addressed the second way, changing the fuel type. The study examined the potential of battery electric vehicles (BEVs) as an alternative fuel type to reduce CO2 emissions in Hungarys transportation sector. The study used secondary data retrieved from Statista and stata.com to analyze the future trends of BEVs in Hungary. The results showed that the percentage of BEVs in Hungary in 2022 was 0.4% compared to the total number of registered passenger cars, which is 3.8 million. The simple exponential smoothing (SES) time series forecast revealed that the number of BEVs is expected to reach 84,192 in 2030, indicating a percentage increase of 2.21% in the next eight years. The study suggests that increasing the number of BEVs is necessary to address the negative impact of CO2 emissions on society. The Hungarian Ministry of Innovation and Technologys strategy to reduce the cost of BEVs may increase the percentage of BEVs by 10%, resulting in a potential average reduction of 76,957,600 g/km of CO2 compared to gasoline, diesel, hybrid electric vehicles (HEVs), and plug-in hybrid vehicles (PHEVs).展开更多
To define the diffusion behavior of harmful exhaust substances from diesel vehicles and support safety risk assessments of underground coal mines,we performed a multi-species coupling calculation of the emission and d...To define the diffusion behavior of harmful exhaust substances from diesel vehicles and support safety risk assessments of underground coal mines,we performed a multi-species coupling calculation of the emission and diffusion of harmful substances from a trackless rubber-wheel diesel vehicle.A computational fluid dynamics(CFD)model of the diffusion of harmful emissions was hence established and verified.From the perspective of risk analysis,the diffusion behavior and distribution of hazardous substances emitted by the diesel vehicle were studied under 4 different conditions;moreover,we identified areas characterized by hazardous levels of emissions.When the vehicle idled upwind in the roadway,high-risk areas formed behind and to the right of the vehicle:particularly high concentrations of pollutants were measured near the rear floor of the vehicle and within 5 m behind the vehicle.When the vehicle idled downwind,high-risk areas formed in front of it:particularly high concentrations of pollutants were measured near the floor and within 5 m from the front of the vehicle.In the above cases,the driver would not breathe highly polluted air and would be relatively safe.When the vehicle idled into the chamber,however,high-risk areas formed on both sides of the vehicle and near the upper roof.Forward entry of the vehicle caused a greater increase in the concentration of pollutants in the chamber and in the driver’s breathing zone compared with reverse entry.展开更多
The reduction of fuel consumption in engines is always considered of vital importance.Along these lines,in this work,this goal was attained by optimizing the heavy-duty commercial vehicle engine control strategy.More ...The reduction of fuel consumption in engines is always considered of vital importance.Along these lines,in this work,this goal was attained by optimizing the heavy-duty commercial vehicle engine control strategy.More specifically,at first,a general first principles model for heavy-duty commercial vehicles and a transient fuel consumptionmodel for heavy-duty commercial vehicles were developed and the parameters were adjusted to fit the empirical data.The accuracy of the proposed modelwas demonstrated fromthe stage and the final results.Next,the control optimization problem resulting in low fuel consumption in heavy commercial vehicles was described,with minimal fuel usage as the optimization goal and throttle opening as the control variable.Then,a time-continuous engine management approach was assessed.Next,the factors that influence low fuel consumption in heavy-duty commercial vehicles were systematically examined.To reduce the computing complexity,the control strategies related to the time constraints of the engine were parametrized using three different methods.The most effective solution was obtained by applying a global optimization strategy because the constrained optimization problem was nonlinear.Finally,the effectiveness of the low-fuel consumption engine control strategy was demonstrated by comparing the simulated and field test results.展开更多
The heavy-duty vehicle fleet involved in delivering water and sand makes noticeable issues of exhaust emissions and fuel consumption in the process of shale gas development. To examine the possibility of converting th...The heavy-duty vehicle fleet involved in delivering water and sand makes noticeable issues of exhaust emissions and fuel consumption in the process of shale gas development. To examine the possibility of converting these heavy-duty diesel engines to run on natural gas-diesel dual-fuel, a transient engine duty cycle representing the real-world engine working conditions is necessary. In this paper, a methodology is proposed, and a target engine duty cycle comprising of 2231 seconds is developed from on-road data collected from 11 on-road sand and water hauling trucks. The similarity of inherent characteristics of the developed cycle and the base trip observed is evidenced by the 2.05% error of standard deviation and average values for normalized engine speed and engine torque. Our results show that the proposed approach is expected to produce a representative cycle of in-use heavy-duty engine behavior.展开更多
Nowadays,the interest in hybrid vehicles is constantly increasing,not only in the automotive sector,but also in other transportation systems,to reduce pollution and emissions and to improve the overall efficiency of t...Nowadays,the interest in hybrid vehicles is constantly increasing,not only in the automotive sector,but also in other transportation systems,to reduce pollution and emissions and to improve the overall efficiency of the vehicles.Although railway vehicles are typically the most eco-friendly transportation system,since commonly their primary energy source is electricity,they can still gain benefits from hybrid technologies,as many lines worldwide are not electrified.In fact,hybrid solutions allow ICEpowered(internal combustion engine)railway vehicles,such as diesel multiple units(DMUs),to operate in fullelectric mode even when the track lacks electrification.The possibility to switch to full electric mode is of paramount importance when the vehicle runs on urban or underground track sections,where low or zero emission levels are required.We conduct the feasibility study of hybridization of an existing DMU vehicle,designed by Blue Engineering S.r.l.,running on the Aosta–Torino Italian railway line,which includes a non-electrified urban track section and an electrified underground section.The hybridization is obtained by replacing one of the diesel generators installed on the original vehicle with a battery pack,which ensures the vehicle to operate in full-electric mode to complete its mission profile.The hybridization is also exploited to implement a regenerative braking strategy,which allows an increase in the energetical efficiency of the vehicle up to 18%.This work shows the sizing of the battery pack based on dynamic simulations performed on the Turin underground track section,and the results demonstrate the feasibility of the hybridization process.展开更多
Fifteen heavy-duty diesel vehicles were tested on chassis dynamometer by using typical heavy duty driving cycle and fuel economy cycle. The air from the exhaust was sampled by 2,4- dinitrophenyhydrazine cartridge and ...Fifteen heavy-duty diesel vehicles were tested on chassis dynamometer by using typical heavy duty driving cycle and fuel economy cycle. The air from the exhaust was sampled by 2,4- dinitrophenyhydrazine cartridge and 23 carbonyl compounds were analyzed by high performance liquid chromatography. The average emission factor of carbonyls was 97.2 mg/km, higher than that of light-duty diesel vehicles and gasoline-powered vehicles. Formaldehyde, acetaldehyde, acetone and propionaidehyde were the species with the highest emission factors. Main influencing factors for carbonyl emissions were vehicle type, average speed and regulated emission standard, and the impact of vehicle loading was not evident in this study. National emission of carbonyls from diesel vehicles exhaust was calculated for China, 2011, based on both vehicle miles traveled and fuel consumption. Carbonyl emission of diesel vehicle was estimated to be 45.8 Gg, and was comparable to gasolinepowered vehicles （58.4 Gg）. The emissions of formaldehyde, acetaldehyde and acetone were 12.6, 6.9, 3.8 Gg, respectively. The ozone formation potential of carbonyls from diesel vehicles exhaust was 537 mg O3/km, higher than 497 mg O3/km of none-methane hydrocarbons emitted from diesel vehicles.展开更多
Pollution can be aggravated in industrial areas if traffic exhausts are mixed with industrial emissions under high humidity conditions. Plants growing in such environments may suffer from severe stress. The impact of ...Pollution can be aggravated in industrial areas if traffic exhausts are mixed with industrial emissions under high humidity conditions. Plants growing in such environments may suffer from severe stress. The impact of vehicle emissions on urban vegetation in an industrial area in Qingdao, China, was investigated by studying seven plant species at visible, physiological and chemical levels. The traits of plant species in certain environmental conditions were compared between a clear area, Badaguan （BDG）, and polluted area, Roadside （RS）. We found that foliar sulfur uptake for all species was not significantly high at RS compared with BDG, although the sulfur content of atmosphere and surface soils at RS were much higher than those at BDG. For Ailanthus altissima Swingle, the content of foliar pigment and net photosynthesis rate （PN） decreased by 20%. Meanwhile, leaves became incrassate and no visible leaf damage was noted, suggesting this species could adapt well to pollution. A 50% decrease in PN occurred in Hibiscus syriacus L., but there was no statistical change in content of chlorophyll a and b and water uptake. Also, thickened leaves may prevent the pollutant from permeation. Foliar water content was still at a low level, although a water compensation mechanism was established for Fraxinus chinensis Rosb. reflected by low water potential and high water use efficiency. More adversely, a 65% decrease in PN happened inevitably with the significant decomposition of photosynthetic pigments, which exhibited visible damage. We also noted in one evergreen species （Magnolia grandifiora L.） that water absorption driven by low water potential should be helpful to supply water loss induced by strong stomatal transpiration and maintain normal growth. Furthermore, photosynthetic pigment content did not decline statistically, but supported a stable net assimilation. Two herbaceous species, Poa annua L. and Ophiopogon japonicus Ker-Gawh, were very tolerant to adverse stress compared to other woody species, especially in assimilation through a compensatory increase in leaf area. A more remarkable decline in PN （decrease 80%） was noted in the exotic but widespread species, Platanus orientalis L., with serious etiolation and withering being exhibited on the whole canopy. Our results suggested, special for woody species, that most native species are more tolerant to pollution and therefore should to be broadly used in a humid urban industrial environment with heavy-duty vehicle emissions.展开更多
Diesel vehicles have caused serious environmental problems in China.Hence,the Chinese government has launched serious actions against air pollution and imposed more stringent regulations on diesel vehicle emissions in...Diesel vehicles have caused serious environmental problems in China.Hence,the Chinese government has launched serious actions against air pollution and imposed more stringent regulations on diesel vehicle emissions in the latest China VI standard.To fulfill this stringent legislation,two major technical routes,including the exhaust gas recirculation(EGR)and high-efficiency selective catalytic reduction(SCR)routes,have been developed for diesel engines.Moreover,complicated aftertreatment technologies have also been developed,including use of a diesel oxidation catalyst(DOC)for controlling carbon monoxide(CO)and hydrocarbon(HC)emissions,diesel particulate filter(DPF)for particle mass(PM)emission control,SCR for the control of NOx emission,and an ammonia slip catalyst(ASC)for the control of unreacted NH3.Due to the stringent requirements of the China VI standard,the aftertreatment system needs to be more deeply integrated with the engine system.In the future,aftertreatment technologies will need further upgrades to fulfill the requirements of the near-zero emission target for diesel vehicles.展开更多
A total of 15 light-duty diesel vehicles（LDDVs） were tested with the goal of understanding the emission factors of real-world vehicles by conducting on-board emission measurements. The emission characteristics of hy...A total of 15 light-duty diesel vehicles（LDDVs） were tested with the goal of understanding the emission factors of real-world vehicles by conducting on-board emission measurements. The emission characteristics of hydrocarbons（HC） and nitrogen oxides（NOx） at different speeds, chemical species profiles and ozone formation potential（OFP） of volatile organic compounds（VOCs） emitted from diesel vehicles with different emission standards were analyzed. The results demonstrated that emission reductions of HC and NOxhad been achieved as the control technology became more rigorous from Stage I to Stage IV. It was also found that the HC and NOxemissions and percentage of O2 dropped with the increase of speed, while the percentage of CO2 increased. The abundance of alkanes was significantly higher in diesel vehicle emissions, approximately accounting for 41.1%–45.2%, followed by aromatics and alkenes. The most abundant species were propene,ethane, n-decane, n-undecane, and n-dodecane. The maximum incremental reactivity（MIR）method was adopted to evaluate the contributions of individual VOCs to OFP. The results indicated that the largest contributors to O3 production were alkenes and aromatics, which accounted for 87.7%–91.5%. Propene, ethene, 1,2,4-trimethylbenzene, 1-butene, and1,2,3-trimethylbenzene were the top five VOC species based on their OFP, and accounted for 54.0%-64.8% of the total OFP. The threshold dilution factor was applied to analyze the possibility of VOC stench pollution. The majority of stench components emitted from vehicle exhaust were aromatics, especially p-diethylbenzene, propylbenzene, m-ethyltoluene, and p-ethyltoluene.展开更多
基金Project(20906067)supported by the National Natural Science Foundation of ChinaProject(2011M500543)supported by the Postdoctoral Science Foundation of ChinaProject supported by the Program for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi
文摘Cu-SAPO-34/cordierite catalysts were prepared via one-step hydrothermal synthesis method and their performances to remove NO x from the diesel vehicle exhaust were evaluated. The morphology, structure, Cu content and valence state were characterized by SEM, XRD, ICP and XPS, respectively. The experimental results show the active component Cu of the catalysts via in situ synthesis could significantly improve the selective catalytic reduction （SCR） activities of NOx and the optimal Cu content is in the range of 0.30%-0.40%（mass fraction）. No N 2 O is detected by gas chromatograph （GC） during the evaluation process, which implies that NOx is almost entirely converted to N2 over Cu-SAPO-34/cordierite catalyst. The conversion rate of NOx to N2 by NH3 over catalyst could almost be up to 100%in the temperature range of 300-670 ℃with a space velocity of 12000 h-1 and it is still more than 60% at 300-620 ℃ under 36000 h-1. The catalysts also show the good hydrothermal and chemical stability at the atmosphere with H 2 O.
文摘The transportation sector is responsible for 25% of the total Carbon dioxide (CO2) emissions, whereas 60.6% of this sector represents small and medium passenger cars. However, as noted by the European Union Long-term strategy, there are two ways to reduce the amount of CO2 emissions in the transportation sector. The first way is characterized by creating more efficient vehicles. In contrast, the second way is characterized by changing the fuel used. The current study addressed the second way, changing the fuel type. The study examined the potential of battery electric vehicles (BEVs) as an alternative fuel type to reduce CO2 emissions in Hungarys transportation sector. The study used secondary data retrieved from Statista and stata.com to analyze the future trends of BEVs in Hungary. The results showed that the percentage of BEVs in Hungary in 2022 was 0.4% compared to the total number of registered passenger cars, which is 3.8 million. The simple exponential smoothing (SES) time series forecast revealed that the number of BEVs is expected to reach 84,192 in 2030, indicating a percentage increase of 2.21% in the next eight years. The study suggests that increasing the number of BEVs is necessary to address the negative impact of CO2 emissions on society. The Hungarian Ministry of Innovation and Technologys strategy to reduce the cost of BEVs may increase the percentage of BEVs by 10%, resulting in a potential average reduction of 76,957,600 g/km of CO2 compared to gasoline, diesel, hybrid electric vehicles (HEVs), and plug-in hybrid vehicles (PHEVs).
基金supported by the National Natural Science Foundation of China(Nos.52174191 and 51874191)the National Key R&D Program of China(No.2017YFC0805201)+1 种基金Qingchuang Science and Technology Project of Shandong Province University(No.2020KJD002)Taishan Scholars Project Special Funding(No.TS20190935).
文摘To define the diffusion behavior of harmful exhaust substances from diesel vehicles and support safety risk assessments of underground coal mines,we performed a multi-species coupling calculation of the emission and diffusion of harmful substances from a trackless rubber-wheel diesel vehicle.A computational fluid dynamics(CFD)model of the diffusion of harmful emissions was hence established and verified.From the perspective of risk analysis,the diffusion behavior and distribution of hazardous substances emitted by the diesel vehicle were studied under 4 different conditions;moreover,we identified areas characterized by hazardous levels of emissions.When the vehicle idled upwind in the roadway,high-risk areas formed behind and to the right of the vehicle:particularly high concentrations of pollutants were measured near the rear floor of the vehicle and within 5 m behind the vehicle.When the vehicle idled downwind,high-risk areas formed in front of it:particularly high concentrations of pollutants were measured near the floor and within 5 m from the front of the vehicle.In the above cases,the driver would not breathe highly polluted air and would be relatively safe.When the vehicle idled into the chamber,however,high-risk areas formed on both sides of the vehicle and near the upper roof.Forward entry of the vehicle caused a greater increase in the concentration of pollutants in the chamber and in the driver’s breathing zone compared with reverse entry.
基金This work was supported in part by the Science and Technology Major Project of Guangxi under Grant AA22068001in part by the Key Research and Development Program of Guangxi AB21196029+3 种基金in part by the Project of National Natural Science Foundation of China 51965012in part by the Scientific Research and TechnologyDevelopment in Liuzhou 2022AAA0102,2021AAA0104 and 2021AAA0112in part by Agricultural Science and Technology Innovation and Extension Special Project of Jiangsu Province NJ2021-21,in part by the Guangxi Key Laboratory of Manufacturing System and Advanced Manufacturing Technology,in part by the Guilin University of Electronic Technology 20-065-40-004Zin part by the Innovation Project of GUET Graduate Education 2022YCXS017.
文摘The reduction of fuel consumption in engines is always considered of vital importance.Along these lines,in this work,this goal was attained by optimizing the heavy-duty commercial vehicle engine control strategy.More specifically,at first,a general first principles model for heavy-duty commercial vehicles and a transient fuel consumptionmodel for heavy-duty commercial vehicles were developed and the parameters were adjusted to fit the empirical data.The accuracy of the proposed modelwas demonstrated fromthe stage and the final results.Next,the control optimization problem resulting in low fuel consumption in heavy commercial vehicles was described,with minimal fuel usage as the optimization goal and throttle opening as the control variable.Then,a time-continuous engine management approach was assessed.Next,the factors that influence low fuel consumption in heavy-duty commercial vehicles were systematically examined.To reduce the computing complexity,the control strategies related to the time constraints of the engine were parametrized using three different methods.The most effective solution was obtained by applying a global optimization strategy because the constrained optimization problem was nonlinear.Finally,the effectiveness of the low-fuel consumption engine control strategy was demonstrated by comparing the simulated and field test results.
文摘The heavy-duty vehicle fleet involved in delivering water and sand makes noticeable issues of exhaust emissions and fuel consumption in the process of shale gas development. To examine the possibility of converting these heavy-duty diesel engines to run on natural gas-diesel dual-fuel, a transient engine duty cycle representing the real-world engine working conditions is necessary. In this paper, a methodology is proposed, and a target engine duty cycle comprising of 2231 seconds is developed from on-road data collected from 11 on-road sand and water hauling trucks. The similarity of inherent characteristics of the developed cycle and the base trip observed is evidenced by the 2.05% error of standard deviation and average values for normalized engine speed and engine torque. Our results show that the proposed approach is expected to produce a representative cycle of in-use heavy-duty engine behavior.
文摘Nowadays,the interest in hybrid vehicles is constantly increasing,not only in the automotive sector,but also in other transportation systems,to reduce pollution and emissions and to improve the overall efficiency of the vehicles.Although railway vehicles are typically the most eco-friendly transportation system,since commonly their primary energy source is electricity,they can still gain benefits from hybrid technologies,as many lines worldwide are not electrified.In fact,hybrid solutions allow ICEpowered(internal combustion engine)railway vehicles,such as diesel multiple units(DMUs),to operate in fullelectric mode even when the track lacks electrification.The possibility to switch to full electric mode is of paramount importance when the vehicle runs on urban or underground track sections,where low or zero emission levels are required.We conduct the feasibility study of hybridization of an existing DMU vehicle,designed by Blue Engineering S.r.l.,running on the Aosta–Torino Italian railway line,which includes a non-electrified urban track section and an electrified underground section.The hybridization is obtained by replacing one of the diesel generators installed on the original vehicle with a battery pack,which ensures the vehicle to operate in full-electric mode to complete its mission profile.The hybridization is also exploited to implement a regenerative braking strategy,which allows an increase in the energetical efficiency of the vehicle up to 18%.This work shows the sizing of the battery pack based on dynamic simulations performed on the Turin underground track section,and the results demonstrate the feasibility of the hybridization process.
基金supported by the Natural Science Foundation for Outstanding Young Scholars(No.41125018)the National Commonweal Project of the Ministry of Environmental Protection(No.201009057)
文摘Fifteen heavy-duty diesel vehicles were tested on chassis dynamometer by using typical heavy duty driving cycle and fuel economy cycle. The air from the exhaust was sampled by 2,4- dinitrophenyhydrazine cartridge and 23 carbonyl compounds were analyzed by high performance liquid chromatography. The average emission factor of carbonyls was 97.2 mg/km, higher than that of light-duty diesel vehicles and gasoline-powered vehicles. Formaldehyde, acetaldehyde, acetone and propionaidehyde were the species with the highest emission factors. Main influencing factors for carbonyl emissions were vehicle type, average speed and regulated emission standard, and the impact of vehicle loading was not evident in this study. National emission of carbonyls from diesel vehicles exhaust was calculated for China, 2011, based on both vehicle miles traveled and fuel consumption. Carbonyl emission of diesel vehicle was estimated to be 45.8 Gg, and was comparable to gasolinepowered vehicles （58.4 Gg）. The emissions of formaldehyde, acetaldehyde and acetone were 12.6, 6.9, 3.8 Gg, respectively. The ozone formation potential of carbonyls from diesel vehicles exhaust was 537 mg O3/km, higher than 497 mg O3/km of none-methane hydrocarbons emitted from diesel vehicles.
文摘Pollution can be aggravated in industrial areas if traffic exhausts are mixed with industrial emissions under high humidity conditions. Plants growing in such environments may suffer from severe stress. The impact of vehicle emissions on urban vegetation in an industrial area in Qingdao, China, was investigated by studying seven plant species at visible, physiological and chemical levels. The traits of plant species in certain environmental conditions were compared between a clear area, Badaguan （BDG）, and polluted area, Roadside （RS）. We found that foliar sulfur uptake for all species was not significantly high at RS compared with BDG, although the sulfur content of atmosphere and surface soils at RS were much higher than those at BDG. For Ailanthus altissima Swingle, the content of foliar pigment and net photosynthesis rate （PN） decreased by 20%. Meanwhile, leaves became incrassate and no visible leaf damage was noted, suggesting this species could adapt well to pollution. A 50% decrease in PN occurred in Hibiscus syriacus L., but there was no statistical change in content of chlorophyll a and b and water uptake. Also, thickened leaves may prevent the pollutant from permeation. Foliar water content was still at a low level, although a water compensation mechanism was established for Fraxinus chinensis Rosb. reflected by low water potential and high water use efficiency. More adversely, a 65% decrease in PN happened inevitably with the significant decomposition of photosynthetic pigments, which exhibited visible damage. We also noted in one evergreen species （Magnolia grandifiora L.） that water absorption driven by low water potential should be helpful to supply water loss induced by strong stomatal transpiration and maintain normal growth. Furthermore, photosynthetic pigment content did not decline statistically, but supported a stable net assimilation. Two herbaceous species, Poa annua L. and Ophiopogon japonicus Ker-Gawh, were very tolerant to adverse stress compared to other woody species, especially in assimilation through a compensatory increase in leaf area. A more remarkable decline in PN （decrease 80%） was noted in the exotic but widespread species, Platanus orientalis L., with serious etiolation and withering being exhibited on the whole canopy. Our results suggested, special for woody species, that most native species are more tolerant to pollution and therefore should to be broadly used in a humid urban industrial environment with heavy-duty vehicle emissions.
基金supported by the National Key R&D Program of China(No.2017YFC0211101)the Key Project of National Natural Science Foundation(No.21637005)+1 种基金the Cultivating Project of Strategic Priority Research Program of Chinese Academy of Sciences(No.XDPB1902)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA23010200)。
文摘Diesel vehicles have caused serious environmental problems in China.Hence,the Chinese government has launched serious actions against air pollution and imposed more stringent regulations on diesel vehicle emissions in the latest China VI standard.To fulfill this stringent legislation,two major technical routes,including the exhaust gas recirculation(EGR)and high-efficiency selective catalytic reduction(SCR)routes,have been developed for diesel engines.Moreover,complicated aftertreatment technologies have also been developed,including use of a diesel oxidation catalyst(DOC)for controlling carbon monoxide(CO)and hydrocarbon(HC)emissions,diesel particulate filter(DPF)for particle mass(PM)emission control,SCR for the control of NOx emission,and an ammonia slip catalyst(ASC)for the control of unreacted NH3.Due to the stringent requirements of the China VI standard,the aftertreatment system needs to be more deeply integrated with the engine system.In the future,aftertreatment technologies will need further upgrades to fulfill the requirements of the near-zero emission target for diesel vehicles.
基金supported by the Natural Sciences Foundation of China(Nos.91544232&51408015)the Ministry of Environmental Protection Special Funds for Scientific Research on Public Causes(No.201409006)+4 种基金the Beijing municipal science and technology plan projects(No.Z131100001113029)the 13th graduate students of science and technology fund of Beijing University of Technology(ykj-2014-11484)the projects supported by Beijing Municipal Commission of Science and Technology(No.Z141100001014002)Beijing Municipal Commission of Education(No.PXM2016_014204_001029)National Science and Technology Support Project of China(No.2014BAC23B02)
文摘A total of 15 light-duty diesel vehicles（LDDVs） were tested with the goal of understanding the emission factors of real-world vehicles by conducting on-board emission measurements. The emission characteristics of hydrocarbons（HC） and nitrogen oxides（NOx） at different speeds, chemical species profiles and ozone formation potential（OFP） of volatile organic compounds（VOCs） emitted from diesel vehicles with different emission standards were analyzed. The results demonstrated that emission reductions of HC and NOxhad been achieved as the control technology became more rigorous from Stage I to Stage IV. It was also found that the HC and NOxemissions and percentage of O2 dropped with the increase of speed, while the percentage of CO2 increased. The abundance of alkanes was significantly higher in diesel vehicle emissions, approximately accounting for 41.1%–45.2%, followed by aromatics and alkenes. The most abundant species were propene,ethane, n-decane, n-undecane, and n-dodecane. The maximum incremental reactivity（MIR）method was adopted to evaluate the contributions of individual VOCs to OFP. The results indicated that the largest contributors to O3 production were alkenes and aromatics, which accounted for 87.7%–91.5%. Propene, ethene, 1,2,4-trimethylbenzene, 1-butene, and1,2,3-trimethylbenzene were the top five VOC species based on their OFP, and accounted for 54.0%-64.8% of the total OFP. The threshold dilution factor was applied to analyze the possibility of VOC stench pollution. The majority of stench components emitted from vehicle exhaust were aromatics, especially p-diethylbenzene, propylbenzene, m-ethyltoluene, and p-ethyltoluene.
