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Comparison of Real-World Emissions from Two-Wheelers and Passenger Cars
Abstract
Passenger cars are the primary means of transportation in Europe. Over the past decade, a great deal of attention has therefore been paid to reducing their emissions. This has resulted in notable technical progress, leading to unprecedentedly low exhaust emissions. In the meantime, emissions from motorcycles have been ignored due to their subordinate role in traffic. Even though the motorcycle fleet is small in comparison with the car fleet, and logs lower yearly mileage per vehicle, their contribution to traffic emissions has become disproportionately high. Exhaust emissions of CO, HC, NOx, and CO2 from 8 powered two-wheelers were measured and compared to previous measurements from 17 gasoline-powered passenger cars performed at EMPA with the aim of ascertaining their relevance. Using exhaust emission ratios from both vehicle types, comparisons based on mean unit, mean yearly, and fleet emissions are considered. Present-day aftertreatment technologies for motorcycles are not as efficient as those for cars. A comparison of mean unit emissions shows that motorcycles exceed cars in NOx emissions. All comparisons reveal a significant HC ratio, to the detriment of two-wheelers. Overall, the relevance of emissions from powered two-wheelers is not negligible when compared with modern gasoline-powered passenger cars.
... Among alternative fuels, the employ of ethanol could be one of means to lessen carbon monoxide and total hydrocarbon emissions from two-wheeler engines and to reduce the depletion of petroleum fuels simultaneously. Emissions of pollutants into atmosphere from two-wheelers are becoming more and more concern in an industrialized society, especially for CO and HC [1,2,3]; due to attractive qualities, such as high maneuverability, parking simply, and inexpensive, motorcycles and mopeds are one of the main modes of carrying in major cities of southern Europe, particularly in Italy where the share of the two-wheelers to the total passenger vehicle fleet is around 25% [4]. Since catalysts are efficient only at high temperature, emissions are far more significant during the first part (cold phase) of a trip, when engine and catalyst are cold; for newly sold motorcycles equipped with a catalytic converter and electronic mixture control, cold-start emissions correspond to an important proportion of total emissions, with an evident consequence on air quality because of their prevailing use in urban environments [5]. ...
... Also Yao studied the effect of ethanol-gasoline blends on criteria air pollutant emissions in a four-stroke motorcycle with a displacement of 125 cm 3 and without a catalytic converter. The ethanol was blended with unleaded gasoline in four percentages (3,10,15, and 20% v/v) and controlled at a constant research octane number, RON (95), to accurately represent commercial gasoline. In general, the exhaust CO and NO X emissions decreased with increasing oxygen content in fuels. ...
... Yang investigated the emission characteristics of regulated air pollutants and carbonyls from nine four-stroke motorcycles using gasoline blended with 3% ethanol. All motorcycles had the same after-treatment device, a two-way catalytic converter, the fuel systems are all carburettor systems, while the displacement volumes were from 100 cm 3 to 150 cm 3 . The results show that average emission factors of CO and THC decreased by 20.0% and 5.27% using ethanolgasoline blend fuel, while NOx and CO 2 emission increased by 5.22% and 2.57% [10]. ...
The object of this study is to investigate the effect of ethanol–gasoline blends on CO and HC cold start emissions from a four- stroke motorcycle. Nowadays, due to catalyst improvements and efficient electronic mixture control, a significant part of the total emissions during a trip takes place during the cold phase. The employ of alternative fuels could be one of means to lessen the cold-start emissions from two-wheeler engines: ethanol is known as potential alcohol alternative fuel for spark ignition engines, which can be blended with gasoline to increase oxygen content and then to decrease CO and HC emissions.
... 53 The percentage of acceleration and deceleration in the driving also plays a vital role in determining the emissions characteristics of vehicles, other than the rate of acceleration and deceleration. Figures 7(a) to (c) and 8(a) to (c) show the relation between increases of the percentage of acceleration and deceleration in the driving cycle increase the tailpipe 49 Tsai et al. 26 Alvarez et al. 9 Vasic et al. 51 Vasic et al. 51 Adak et al. 24 Tsai et al. 26 Tuan et al. 50 Tung et al. 7 Chen et al. emissions, particularly the carbon monoxide (CO) and hydrocarbon (HC). ...
... 53 The percentage of acceleration and deceleration in the driving also plays a vital role in determining the emissions characteristics of vehicles, other than the rate of acceleration and deceleration. Figures 7(a) to (c) and 8(a) to (c) show the relation between increases of the percentage of acceleration and deceleration in the driving cycle increase the tailpipe 49 Tsai et al. 26 Alvarez et al. 9 Vasic et al. 51 Vasic et al. 51 Adak et al. 24 Tsai et al. 26 Tuan et al. 50 Tung et al. 7 Chen et al. emissions, particularly the carbon monoxide (CO) and hydrocarbon (HC). ...
This paper proposed a framework for development of real-world driving cycle in India after a thorough review and comparison of motorcycle driving cycles used in different countries. A limited state-of-the art work for the development of driving cycles for motorcycles is available. The motorcycle driving cycles developed by different countries differ from each other in terms of their driving cycle characteristics, emission factors, and fuel economy. This paper reviewed the parameters of real-world driving cycles of motorcycles and compares the same with legislative cycles concerning their characteristics and emissions. The parameters of real-world driving cycles and Indian legislative cycle (IDC) deviate significantly from other legislative cycles in the range of-97% to + 1172% and-74% to 284% respectively. The emission factors of the legislative cycle do not match with the realistic emissions measured by real-world driving cycles. This is due to the reason that the legislative cycles do not represent the current traffic scenario and hence need to be revised. A framework is proposed to develop a real-world driving cycle in India.
... The market share of Euro 4 motorcycles in 2020 is estimated to be around 10%-15% assuming that 65%-100% of registrations since 2016 fulfil the Euro 4 standards, and assuming a fleet of 25 million motorcycles (it was 24 million in 2018). There are many studies that have examined the emissions of motorcycles [12][13][14][15][16][17][18][19][20][21][22][23][24], but not many for large displacement motorcycles [25][26][27][28]. However, the data for Euro 4 motorcycles are almost non-existent, with limited data in the Euro 5 L-category study [29] (no emission results for Euro 4 motorcycles) or sometimes at reported values from type approval authorities [30]. ...
... Small differences could only been seen in the lambda values (see Appendix A, Figure A1) and only minor in the speed traces (see Appendix A, Figure A2). In all cases the emissions respected the Euro 4 limits and they were much lower compared to those reported in the literature for older motorcycles [26][27][28]. The specific motorcycle could also fulfil the upcoming Euro 5 limits (except NO x with driver 2). ...
Air pollution remains a serious concern for European citizens. The relative contribution of mopeds and motorcycles to air pollution started to increase as the levels from other vehicles started to decrease. The information on emission levels of Euro 4 motorcycles is limited because they were only recently introduced into the market (2016). In this study, the emissions of a 1 L Euro 4 motorcycle were determined with two drivers and two different sampling configurations (i.e., open or closed transfer tube to the dilution tunnel; both allowed in the current regulation). The motorcycle respected the current Euro 4 limits and even the future Euro 5 limits for most pollutants (CO 600 mg/km, NOx 48 mg/km, total hydrocarbons 60 mg/km). The particulate emissions, which are not regulated for this category of vehicles, were also very low and fulfilled the current limits of passenger cars (particulate mass <0.5 mg/km, particle number 3 × 10^11 p/km). The total particle emissions (i.e., including volatiles) were also low with the open configuration (6 × 10^11 p/km). They increased more than one order of magnitude with the closed configuration due to desorption of deposited material from the transfer tube. For the gaseous pollutants, there was no significant difference between open or closed configuration (CO2 within 0.3%, rest pollutants 10%), but they were different between the two drivers (CO2 1.3%, rest pollutants 25%–50%). The main message from this work is that open and closed configurations are equivalent for gaseous pollutants but the open should be used when particles are measured.
... The whole exhaust gas was diluted in the dilution tunnel with constant volume sampling (CVS) set to 3.5 m 3 /min. With this flow rate, the under-pressure at the tailpipe of the moped is small, and similarly its influence on emissions [23]. The dilution tunnel and the CVS were in the climatic room kept at 20-24 °C. ...
... The dilution factor of this first dilution is not known; based on some steady state tests it is expected to be around 2:1 at the maximum speed and higher at lower speeds [14,19]. This configuration (open transfer tube) is allowed in the EU motorcycles/mopeds regulation, and it has been used previously [23]. We note, however, that the closed configuration is more common [7,[27][28][29][30][31][32]. ...
The recent Euro 4 and 5 environmental steps for L-category vehicles (e.g., mopeds, motorcycles) were mainly designed to reduce the emissions of particulate matter and ozone precursors, such as nitrogen oxides and hydrocarbons. However, the corresponding engine, combustion, and aftertreatment improvements will not necessarily reduce the solid particle number (SPN) emissions, suggesting that a SPN regulation may be necessary in the future. At the same time, there are concerns whether the current SPN regulations of passenger cars can be transferred to L-category vehicles. In this study we quantified the errors and uncertainties in emission measurements, focusing on SPN. We summarized the sources of uncertainty related to emission measurements and experimentally quantified the contribution of each uncertainty component to the final results. For this reason, gas analyzers and SPN instruments with lower cut-off sizes of 4 nm, 10 nm, and 23 nm were sampling both from the tailpipe, and from the dilution tunnel having the transfer tube in closed or open configuration (i.e., open at the tailpipe side). The results showed that extracting from the tailpipe 23–28% of the mean total exhaust flow (bleed off) resulted in a 24–31% (for CO2) and 19–73% (for SPN) underestimation of the emissions measured at the dilution tunnel. Erroneous determination of the exhaust flow rate, especially at cold start, resulted in 2% (for CO2) and 69–149% (for SPN) underestimation of the tailpipe emissions. Additionally, for SPN, particle losses in the transfer tube with the closed configuration decreased the SPN concentrations around 30%, mainly due to agglomeration at cold start. The main conclusion of this study is that the open configuration (or mixing tee) without any instruments measuring from the tailpipe is associated with better accuracy for mopeds, especially related to SPN measurements. In addition, we demonstrated that for this moped the particle emissions below 23 nm, the lower size currently prescribed in the passenger cars regulation, were as high as those above 23 nm; thus, a lower cut-off size is more appropriate.
... The popularity of the motorcycle for personal and taxi use is due to many factors including lower upfront costs, lack of regulation, and mobility in highly congested urban contexts (Posada et al. 2011;UNECE 2018). While motorcycles are often seen as a more fuelefficient alternative, emissions can be worse from two-wheelers than cars, particularly nitrogen oxides (NOx), carbon monoxide (CO), and hydrocarbon emissions (Vasic and Weilenmann 2006;Ehebrecht et al. 2018). These two-wheeler emissions contribute to dangerous levels of air pollution across many cities in low-and middle-income countries. ...
This Working Group III contribution to the IPCC Sixth Assessment Report provides a comprehensive and transparent assessment of the literature on climate change mitigation. The report assesses progress in climate change mitigation options for reducing emissions and enhancing sinks. With greenhouse gas emissions at the highest levels in human history, this report provides options to achieve net zero, as pledged by many countries. The report highlights for the first time the social and demand-side aspects of climate mitigation, and assesses the literature on human behaviour, lifestyle, and culture, and its implications for mitigation action. It brings a wide range of disciplines, notably from the social sciences, within the scope of the assessment. IPCC reports are a trusted source for decision makers, policymakers, and stakeholders at all levels (international, regional, national, local) and in all branches (government, businesses, NGOs). Available as Open Access on Cambridge Core.
... Considering the total number of vehicles without discriminating among the various types (i.e., cars or motorcycles) can give a distorted vision of an institution's sustainability because of the different environmental impacts of different kinds of vehicles. As a clear example, the amount of CO2 emitted per kilometer and per user and the amount of air pollutants differ substantially based on whether a car or a motorcycle is chosen [50,51]. An improved indicator should employ proper estimations of the CO2 emitted per kilometer by each type of vehicle and then multiply the same value by the actual kilometers travelled. ...
The Universitas Indonesia GreenMetric World Ranking is the most widely adopted system nowadays to rank worldwide universities' sustainability. The number of participating universities has consistently increased throughout the last decade. An in-depth analysis of this ranking system is made to assess how sustainability in universities is measured through specific indicators. Specifically, based on expert knowledge, common logic and the scientific literature, these indicators are assessed with respect to whether they can be used to fairly quantify and rank worldwide uni-versities' sustainability development. Some indicators proposed by the ranking system, such as the number of renewable energy sources on campus and the number of various types of programs for sustainable development, were found to be unable to measure any sustainability development effectively and fairly. Many others, such as the opted sewage disposal modality, the percentage of university budget for sustainability efforts and the ratio of sustainability research funding to total research funding, were found to need adjustment to account for context-specific factors such as availability of renewable energy sources, weather, landscape, original construction and the cultural habits of the enrolled people. Taking into account these considerations, a fairer evaluation and comparison of universities' sustainability could be achieved which provides universities with information on how to effectively improve their sustainability.
... The easing of the lockdown was not yet complete. There were many activities which when permitted, would lead to higher pollution levels and these included motor cycles which are known to be even more polluting that other motor vehicles (Vasic and Weilenmann, 2006). Students were still at home and the curfew still ...
... Compared to cars, motorcycles emit more pollutants per mileage travel, although they have smaller displacements than cars (Fu et al. 2020). Vasic and Weilenmann (2006) reported that the ratios of emission factors between motorcycles and cars were very high, especially for HC (222/1) in urban driving mode. Moreover, it was reported that the carcinogenic potencies of PAHs from motorcycles were several hundred times higher than those from automobiles (Yang et al. 2010). ...
The motorcycles are unignorable near-ground pollutant emission sources that increase the human exposure in the dense area. However, the information of the polycyclic aromatic hydrocarbons (PAHs) emissions under different scenarios of engine and emission control for motorcycle is limited. This study focused on the PAH emissions from two fuel-injection types of motorcycles, including the premixed fuel-injection (PFi) with carburetor and electronic fuel-injection (EFi). Specifically, the effects of throttle opening (TO), secondary air system (SAS), oxygen sensor (OS), oxidation catalytic converter (OCC), and three-way catalytic converter (TWC) on PAH emissions are investigated. Results show that the PAH emission concentrations increase 227–727%, 351–492%, and 155–408% by the increasing TO ratio, unworking SAS, and OS units in both motorcycles. For the PFi engine, the OCC unit is found to be more effective in PAH control (31–89%) than the SAS system (72–80%), especially under low TO operation. For the EFi engine which dominates the motorcycle market recently, the oxygen sensor for more accurate combustion control shows a better PAH reduction (36–76%) than TWC system (21–66%). The ultra-fine particulate phase PAHs, which is hardly removed by catalyst, needs to be further considered. Moreover, the total PAH emission level of the EFi engine is still about ten times higher than that of the PFi. By the annual emission calculation for three densely populated countries, the recent evolution significantly reduces the annual hydrocarbon (HC), carbon monoxide (CO), and nitrogen oxide (NOx) emissions but have unignorable PAH emissions. These emissions continuously affect the human health in the near-ground urban air and need to be considered in the next generation of motorcycle design.
Graphical abstract
... The aggregated emission estimations are provided in Table 5 (Laurent, 2021;Osei et al., 2021), while there is also the argument that NOx and PM2.5 emissions have dropped by 31% and 15% respectively within the current ULEZ boundaries -covering central London. Assuming reliability of these reports, the computation for NOx estimations presented in Table 5 Significant VKT growth by 29% can also be noticed for two-wheeled vehicles (Table E-3), that are well known to contribute substantially to CO emissions , where in some cases it has been found that they emit three times more CO compared to conventional cars (Vasic and Weilenmann, 2006). This is also reflected in the high levels of CO produced by these vehicles as shown in Table 5-16, where two-wheeled vehicles account for over 10% in all cases in London. ...
An expanding street network coupled with an increasing number of vehicles testifies to the significance and reliance on road transportation of modern economies. Unfortunately, the use of road transport comes with drawbacks such as its contribution to greenhouse gases (GHG) and air pollutant emissions, therefore becoming an obstacle to countries’ objectives to improve air quality and a barrier to the ambitious targets to reduce Greenhouse Gas emissions. Unsurprisingly, traffic forecasting, its environmental impacts and potential future configurations of road transport are some of the topics which have received a great deal of attention in the literature. However, traffic forecasting and the assessment of its determinants have been commonly restricted to specific, normally urban, areas while road transport emission studies do not take into account a large part of the road network, as they usually focus on major roads. This research aimed to contribute to the field of road transportation, by firstly developing a model to accurately estimate traffic across England and Wales at a granular (i.e., street segment) level, secondly by identifying the role of factors associated with road transportation and finally, by estimating CO2 and air pollutant emissions, known to be responsible for climate change as well as negative impacts on human health and ecosystems. The thesis identifies potential emissions abatement from the adoption of novel road vehicles technologies and policy measures. This is achieved by analysing transport scenarios to assess future impacts on air quality and CO2 emissions. The thesis concludes with a comparison of my estimates for road emissions with those from DfT modelling to assess the methodological robustness of machine learning algorithms applied in this research. The traffic modelling outputs reveal traffic patterns across urban and rural areas, while traffic estimation is achieved with high accuracy for all road classes. In addition, specific socioeconomic and roadway characteristics associated with traffic across all vehicle types and road classes are identified. Finally, CO2 and air pollution hot spots as well as the impact of open spaces on pollutants emissions and air quality are explored. Potential emission reduction with the employment of new vehicle technologies and policy implementation is also assessed, so as the results can support urban planning and inform policies related to transport congestion and environmental impacts mitigation. Considering the disaggregated approach, the methodology can be used to facilitate policy making for both local and national aggregated levels.
... On the other hand, an increase in N 2 O emissions was detected for the mopeds and motorcycles class (Table S4). These diversifications most likely reflect the varying age of the engines and the driving conditions (Giechaskiel, 2020;Vasic and Weilenmann, 2006). ...
Emissions of atmospheric pollutants are well-known for their adverse effects on air quality and public health. Additionally, GHG emissions are responsible for the so called “Radiating Forcing” leading to climate change and degradation of ecosystem services. In this work, we analyze the annual emission trends of various air pollutants, including GHGs, from all 4 sectors of transport (roads, aviation, navigation, and railway) in Greece during the 28-year period between 1990 and 2017, in order to examine the confounding dynamics among external forces, such as the major fiscal recession of 2008, and the GHG/pollutant emissions in the country. The analysis is performed with a suite of statistical tools consisting of bivariate correlation analysis, Mann–Kendall test, Sen’s slope estimation, and Joinpoint regression analysis, in order to thoroughly study the trends of emissions. It is found that all transport sectors (except for the railway) show a significant increase in their emissions, despite the fiscal recession of 2008 that temporarily decelerated all aspects of economic activity in the country. Given the major share of transport in GHG emissions (37%) and air pollution in urban centers, it is essential that the road sector adapts to the new challenges, by means of switching to low-emission technologies and electromobilization. The same applies for the navigation and aviation sectors, which are known pillars of the tourist industry in the country.
... This journal is directed at extending the knowledge of the consequents bioethanol/gasoline fuel blends have when applied in a large displacement motorcycle. This focus emerges from the want to evaluate the effect on the urban air quality of two-wheeler class vehicles when applied as a means of transport in major cities of southern Europe [7] [8]. Ethanol Direct Injection plus Gasoline Port Injection (EDI + GPI) is a new technology to harness ethanol fuel more efficiently and effectively in spark-ignition engines than E10 or E85 in the current commerce [9]. ...
The objective of this research is to investigate the effect of ethanol-gasoline mixes on the performances of a four-stroke Spark-Ignition engune. Ethanol is observed as an alternative fuel for Spark-Ignition engines and is known for producing blends with gasoline. An experimental investigation was performed on the engine is a four-stroke cycle single-cylinder, engine volume of 124,8 cm 3 , port fuel injection, a compression ratio of 9,3:1 ,and a Euro 3 large-size motorcycle fuelled with commercial gasoline with a Research Octane Number (RON) of 95 and gasoline/ethanol mixes G25, G35 and G45 (range of 25%, 35%, and 45%). The experiments were performed utilizing spark plug no ground-electrodes type, varied engine speeds of 4000-9000 rpm. Regulated and unregulated performances and fuel consumption were measured over the carrying out of chassis-dynamometer tests. The combustion analysis, actualized by taking the pressure cycle inside the cylinder, highlights the autoregulation of the engine control unit and guarantees utilize within the same parameters of various tested fuels, with the besides of fuel injection time, which escalates with increasing ethanol percentage. The maximum power, mean effective pressure and efficiency thermal values were obtained with an ethanol-gasoline mix (G45) the position with operated at 7000 rpm. A significant decrease in specific fuel consumption was observed using an ethanol-gasoline mix of G45 (45%)
... Unburned hydrocarbon (HC) is one of the important regulated pollutants emitted from motorcycles. HC emission factor from motorcycles can be 100-200 times higher than passenger cars (Vasic and Weilenmann, 2006;Zhou et al., 2014). ...
This study investigates the secondary organic aerosol (SOA) formation potential of carburetor motorcycles exhaust. This type of two-wheeler is a popular means of transport in many Asian cities. A volatility-based numerical model was employed to predict SOA formation from a fleet of motorcycles in Tehran, capital of Iran. The fleet was a combination of four-stroke, gasoline-powered motorcycles with different engine displacement volumes. Total hydrocarbon (THC) emission factors of all motorcycles were previously measured in a chassis dynamometer laboratory according to cold start Euro-3 emissions certification test procedures. Due to incomplete combustion and lack of control on exhaust emissions, unburned fuel was assumed to be a good surrogate for the exhaust of carburetor motorcycles, regarding SOA formation. 150 cc engine and 200 cc engine motorcycles had the highest SOA formation potential, under atmospheric oxidant concentration, while 125 cc engine motorcycles had the highest SOA emission factor (travel-and fuel-based). It was found out that SOA emission factor of 125 cc engine motorcycles could increase up to 20%, three to five years after production. Average SOA formation from carburetor motorcycles in the present study was 4 times higher than Euro-4 passenger cars and 20 times higher than direct emission of particles from Euro-2 motorcycles and on (according to EMEP/EEA levels for PM 2.5 emission factors). Carburetor motorcycles with 180 cc engine volume in the present study, had the lowest SOA formation potential.
... These data are also confirmed by other studies in the literature, which have also warned about their direct emissions of CO, HC, and NO x , which can reach considerable values especially for older models and in South East Asian states such as Vietnam, India, Indonesia, Thailand, Taiwan, and China, where motorcycles make up over 60% of the passenger vehicle fleet [53]. ...
This paper provides an overview of the environmental impacts of different types of passenger transportation means (i.e., bicycles, motorcycles, cars, buses, trains, and airplanes). The method has been applied to the European scenario. The study was performed by using life cycle assessment in accordance with international standard ISO 14040/44 for assessing the CO2 eq., SO2, and PM10 of the transportation means by exploiting data (i.e., vehicles features and environmental impacts) from 24 scientific papers from the literature that have been manually analyzed. The functional unit is defined as the impact per 1 passenger over 1 km. The study identified that planes are the most impacting for CO2 eq. with up to 380 g/pkm, while cars are the most impacting for SO2 with up to 1.78 g/pkm and PM10 with 0.98 g/pkm. Electric and hybrid models proved to be significantly better than others, while buses are the most sustainable in general. Referring to the overall European scenario, cars constitute up to 95% of the overall impacts. By comparing some improvements for reducing the impacts, it emerged that the limitation of diesel cars along with the increase of buses and trains are the most effective. The provided outcomes may be useful for legislators, manufacturers, and users for favoring the choice of the transportation means in a more environmentally conscious way.
... Secondly, this work reveals a significant contribution of motorcycles to PM emissions in DN. Emission of high levels of hydrocarbons (HC), carbon monoxide (CO) and nitrogen oxide (NO x ) from motorcycles can also be significant (Chen et al., 2003;Vasic & Weilenmann, 2006). We believe that the assessment of PE to these gaseous pollutants should also be considered for future studies. ...
The present study investigated the personal exposure (PE) of commuters to fine particles (PM2.5) and black carbon (BC) in two cities: Singapore and Danang (Vietnam) with different socio-economic conditions. The PE measurement was conducted during a multimodal round trip from Singapore to Danang and back with various on-road transport modes in urban micro-environments within each city by using portable devices. Real-time assessment of PE revealed that more than 60% of the integrated inhaled dose of PM2.5 by commuters to occurred at airport concourses and transit micro-environments to/from the aeroplane by apron bus. Whereas for BC, the transit by apron bus made a major contribution (> 50%) to the total integrated exposure. The PE to PM2.5 and BC in transport micro-environments was an order of magnitude higher in Danang compared to Singapore while using various on-road modes of transport in each city. Elevated concentrations of airborne particles in Singapore and Danang were significantly contributed by heavy-duty diesel vehicles and motorcycles, respectively. Moreover, a reduction in years of life expectancy is likely to occur among urban commuters while using motorized transport compared to active mobility (cycling).
(free download link within 50 days: https://authors.elsevier.com/c/1bizL7sfVY-yxT)
... Although motorcycles have lower fuel consumption per individual relative to four-wheel passenger cars due to their smaller engine capacity and lighter weight, motorcycles emit more pollutants per driving mileage (known as their emission factor), since the combustion of motorcycle engines is usually incomplete, and what is worse, they have poorer emission control/aftertreatment technologies. Vasic and Weilenmann (2006) observed that the ratios of mean emissions in g km -1 from motorcycles and cars are very high, especially for HC in urban driving (factor of 222). When emissions were measured in terms of fuelbased emission factors (g L -1 ), the fuel-based emission factors of LDMCs (light-duty motorcycles) and HDMCs (heavyduty motorcycles) registered in or after the year 2000 were about 120 times higher than those of LDGVs (light-duty gasoline vehicles) in the same age group. ...
... Also, in the EU, emission standards for two wheeled vehicles are less stringed comparing to passenger cars (Directive, 2002/51/EC). Finally, after treatment technologies for motorcycles are not as efficient as those for cars (Vasic and Weilenmann, 2006). Trucks are the second emitters (20.3% of CO emissions in Chios and 29.88% in Lesvos) and PCs are the last (19.8% in Chios and 15.0% in Lesvos). ...
... Modern vehicles are equipped with a spark ignition engine with fuel injection and electronic mixture control, and a three-way catalyst; as a result, CO and unburned HC emissions in cold conditions represent a significant share of total emissions if compared with those given off in warm conditions. The cold-start performance of vehicle engines remains a crucial phase because the thermal efficiency of last generation engines is significantly lower at cold-start than the steady-state conditions (Vasic and Weilenmann, 2006). The poor cold-start performance assigns a high fuel consumption. ...
Carbon monoxide (CO) is a poisonous gas particularly to all leaving being present in the atmosphere. An estimate has shown that the vehicular exhaust contributes the largest source of CO pollution in developed countries. Due to the exponentially increasing number of automobile vehicles on roads, CO concentrations have reached an alarming level in urban areas. To control this vehicular exhaust pollution, the end-of-pipe-technology using catalytic converters is recommended. The catalysts operating efficiently in a catalytic converter are a challenging class of materials for applications in cold start of engines to maintain indoor air quality. In the cold start period, the catalytic converter was entirely inactive, because the catalytic converter had not been warmed up. The cold start phase is also depending upon the characteristics of vehicles and property of catalysts. The increasing cost of noble metals with the increasing number of vehicles motivates the investigation of material concepts to reduce the precious metal content in automotive catalysts or to find a substitute for noble metals. Hopcalite (CuMnOx) catalyst could work very well at the low temperature; thus, it can overcome the problem of cold-start emissions if used in a catalytic converter. Further, low cost, easy availability and advanced synthesis methods with stabilizer, promoter, etc., advocates for the use of hopcalite as an auto exhaust purification catalyst. Although there are numerous research articles present on this topic until now, no review has been presented for demanding this issue. So there is a space in this area, and it has been made an attempt to seal this hole and progress the future scope for hopcalite catalyst for purification of exhaust gases by this review. Keywords: Automobile vehicle, Hopcalite catalyst, Catalytic converter applications, Cold start emission, Carbon monoxide
... The incidence of lung cancer especially with the histopathological shift towards lung adenocarcinoma in non-and never smokers are increasing, particularly in the Asian female population (Nakamura et al., 2013;Ha et al., 2014). Whilst lung cancer is the number one killer of all cancer death globally, lung cancer in non-smokers, if considered as a separate entity, would be ranked the seventh most deadly cancer, with an estimation of 200,000 lung cancer deaths globally (Sun et al., 2007). Therefore, there is high interest in the field to elucidate and stratify the risk for lung cancers from the perspective of ambient air pollution. ...
Objective:
Epidemiological studies have reported the close relationship between risk for lung cancers and air pollution
in particular, for non-smoking related lung cancers. However, most studies used residential address as proxies which may
not estimate accurately an individual's air pollution exposure. Therefore, the aim of this study was to identify risk factors
such as occupation and mode of transportation associated with lung cancer diagnosis and death.
Methods:
Subjects
with lung cancer (n=514) were evaluated both by chart reviews for clinical data and interviews to determine residential
address for ten years, main occupation and main mode of transportation. Annual particulate matter with diameter size
less than 2.5 micrometre (PM2.5) concentration were calculated based on particulate matter with diameter size less than
10 micrometre (PM10) data recorded by Malaysian Department of Environment. Logistic regression analysis, cluster
analysis and the Cox regression analysis were performed to the studied variables.
Results:
This study concurred with
previous studies that lung adenocarcinoma were diagnosed in predominantly younger, female non-smokers compared
to the other types of lung cancers. Lung adenocarcinoma subjects had annual PM2.5 that was almost twice higher than
squamous cell carcinoma, small cell carcinoma and other histological subtypes (p=0.024). Independent of smoking,
the κ -means cluster analysis revealed two clusters in which the high risk cluster involves occupation risk with air
pollution of more than four hours per day, main transportation involving motorcycle and trucks and mean annual PM2.5
concentration of more than 30 based on residential address for more than ten years. The increased risk for the high-risk
cluster was more than five times for the diagnosis of lung adenocarcinoma (OR=5.69, 95% CI=3.14-7.21, p<0.001).
The hazard ratio for the high-risk cluster was 3.89 (95% CI=2.12-4.56, p=0.02) for lung adenocarcinoma mortality at
1 year.
Conclusion:
High-risk cluster including PM2.5, occupation risk and mode of transportation as surrogates for
air-pollution exposure was identified and highly associated with lung adenocarcinoma diagnosis and 1-year mortality.
... In an analysis of a random sample of motorcycle advertisements, no example was found that showed the CO 2 emissions of the vehicles, the fuel consumption, or information about the noise levels produced by the vehicles. Thus, no reference was made to any of the multiple atmospheric pollutants produced by motorcycles, even though in some cases this pollution broadly exceeds the impact of cars (Vasic and Weilenmann, 2006). Concerning motorcycles, the environmental scenario in 2015 and 2016 was quite similar to that in 2007 because advertising continues to not show emissions or fuel consumption information. ...
Climate change, which is mostly caused by CO 2 emissions, continues to be a serious environmental problem. The dissemination of correct information regarding the environmental impact of car CO 2 emissions and fuel consumption promoted by responsible advertising plays an important role in this problem. This article proposes that the promotion of responsible car advertising could serve as a tool for reducing climate change and decarbonizing transport. Thus, a qualitative and quantitative study was performed to analyse the influence of car advertising on CO 2 emissions and attitudes regarding such emissions. The results of this study add value to the limited literature in the field of advertising, cars, and the environment. The analysis of the car advertising sector in Spain in 2007, 2015, and 2016 detected a low presence of good practices. Advertisements lack information regarding energy problems related to mobility, emissions, and climate change. There is an effort to hide CO 2 emissions and fuel consumption information in advertising, energy labels are not presented, and information related to efficient driving or moderate vehicle use is lacking. Although the evolution of information regarding emissions and consumption has improved over time with respect to size and location in the advertisements, such data remains marginal. Recent car advertising does not highlight the environmental consequences of the products or offer advice to consumers regarding habits that can help reduce pollution or emissions. Finally, based on this analysis, a detailed code of 28 good practices for the responsible advertising of cars is proposed.
... Other related study such as Prati and Costagliola (2009) reported that a 2-stroke motorcycle emitted about three times more quantified organic compounds compared to a 4-stroke engine in the chassis dynamometer test. Several studies also reported that 4-stroke motorbikes, indeed, release less hydrocarbon than 2-stroke scooters or motorcycles (Alvarez, 2009;Durbin et al., 2004;Leong et al., 2002;Matlrelet al., 2004;Saxer et al., 2006, Vasic et al., 2006. ...
Average emission factors of air toxic compounds, emitted from motorcycles in Bangkok, Thailand were analyzed using the IVE
(International Vehicle Emission) model. The model was utilized taking into account the actual fleet and characteristics of
motorcycles of the study area. Four air toxic compounds (namely benzene, 1,3 butadiene, acetaldehyde and formaldehyde) and
their emission rates were calculated under two main pollution abatement scenarios (the improvement of fuel quality and
switching of fuel types). The results were then compared with the BAU (Business as Usual) case to illustrate the effectiveness
and appropriateness of proposed measures. In the BAU scenario the average emission factors of air toxics from motorcycles were
greatly reduced by the replacement of engine technology from the carburetor system with the electronically controlled fuel
injection system. Improvement of fuel quality standard (from EURO II to EURO IV) resulted in a decrease in average emission
factors of air toxics from motorcycles. Calculated results indicated that the average emission factors of air toxic compounds in
the year 2012 when this policy began as implemented by the Thai government were approximately 93 %, 62 %, 59 % and 59 %,
a decrease as compared to the BAU case in the same year for benzene, 1,3-butadiene, acetaldehyde and formaldehyde,
respectively. The introduction of gasohol as alternative fuel was found to greatly influence the emission factors of acetaldehyde
and formaldehyde. Calculated results in the year 2012 indicated that acetaldehyde average emission factor increased from
123mg/km (BAU case) to 2,272 mg/km (gasohol scenario) in the same year. However, the average emission factors of benzene
and 1,3 butadiene that were the result of gasohol usage were less when compared with the BAU case.
Key words: air toxic emission, dynamic emission factor, gasohol emission, motorcycle
... The present investigation focused on these specific vehicles for several reasons. The two-wheeler class, in fact, is very utilised as widespread means of quotidian moving in main Asian and European cities, in which motorcycles and mopeds represent a large proportion of motorised vehicles [13,14]. In recent years, powered two-wheelers accounted for about 32 million vehicles in the EU-27, making up around 8% of the urban vehicle fleet [15]. ...
Modern vehicles equipped with a spark ignition engine come with fuel injection and electronic mixture control, in combination with a three-way catalyst: As a result, carbon monoxide and unburned hydrocarbon cold emissions represent a significant share of total emissions if compared with those given off in hot conditions, so implying direct consequences on the air quality of metropolitan areas. The purpose of this research is to investigate the engine efficiency and emissive performance of last generation engines during the cold-start phase. For this aim, an experimental-analytical procedure was optimised and applied to study the cold emission behaviour of two motorcycles, characterised by similar technical specifications; the exhaust emissions of these motorcycles were measured on a chassis dynamometer in the laboratories of the National Research Council (CNR-Italy). By using this calculation procedure and the emission results measured during the experimental tests, the duration of the cold phase and the total emissions released during the cold-start transient were evaluated for carbon monoxide and unburned hydrocarbons. The average values of cold emission factors and warm-up transient durations obtained for unburned hydrocarbons were 1.05 g/km and 162 s, respectively. Regarding carbon monoxide, the average values of cold emission factors and warm-up transient durations were 14.9 g/km and 152 s, respectively. The results of this study are very useful for better characterising the emission levels of the last generation motorcycles under real urban conditions.
... On a per vehicle basis, motorbikes have been shown to emit more nitrogen oxides than cars (e.g. Vasic and Weilenmann, 2006). Column (5) in Tables 4, 6, and 8 includes a variable for the number of motorbikes per 1,000 city residents, which is allowed to vary depending on whether cities are located in OECD or non-OECD cities (see also Panel D in Figure A1, Appendix B). ...
... Uno studio riferito alla città di Genova tra il 1992 e il 2010 [4] ha stimato il contributo dei motocicli alle emissioni totali di CO ed HC intorno al 38% e 27%, rispettivamente, nell'anno 2010. Gli elementi che rendono critiche queste categorie di veicoli sono le tecnologie di post-trattamento dei gas di scarico, meno efficienti rispetto a quelle delle auto [5,6] e la scarsa qualità della combustione, non ottimizzata in termini di rapporto aria/combustibile, che è spesso responsabile di alte emissioni di HC e PM [7,8,9,10]. D'altro canto, questi veicoli sono caratterizzati da bassi consumi di combustibile e presentano quindi ridotte emissioni di CO 2 , stimate in Italia intorno al 5% del totale annualmente dovuto ai veicoli stradali [11]. ...
SOMMARIO La crescente incidenza dei veicoli a due ruote sul parco circolante in ambito urbano e sulle emissioni inquinanti da esso prodotte rende necessaria un'adeguata valutazione dell'impatto ambientale e dei consumi energetici di queste categorie di veicoli (motocicli e ciclomotori), con particolare riguardo al funzionamento durante il transitorio a freddo del motore ed al comportamento cinematico in condizioni di reale utilizzazione, aspetti fondamentali per la valutazione delle relative emissioni allo scarico e consumi di combustibile. In una prima fase, lo studio ha riguardato lo sviluppo di procedure per la definizione della sovraemissione a freddo, partendo dall'elaborazione di database definiti in altre indagini (progetto europeo Artemis, definizione dell'equivalenza cicli europeo/WMTC), per diverse classi di motocicli, differenziate per fase normativa e tipologia di motore. Tale indagine ha evidenziato la mancanza di informazioni relative alle classi normative più recenti (in particolare Euro 3 per le moto) e di cicli di guida specifici per veicoli a due ruote. Nella seconda fase dello studio l'Internal Combustion Engines Group (ICEG), operante presso l'Università di Genova, ha quindi condotto un'estesa campagna sperimentale sul territorio genovese, con veicoli strumentati per l'acquisizione della velocità istantanea durante lo svolgimento di prefissati percorsi caratteristici. Dall'elaborazione dei dati si sono ricavati alcuni profili di velocità che, insieme a cicli di omologazione, cicli reali e cicli di guida appositamente definiti per la valutazione delle sovraemissioni a freddo (IRC e IUFC), sono stati utilizzati per testare alcuni motocicli Euro 3 sul banco a rulli del Laboratorio Emissioni dell'Istituto Motori del CNR di Napoli. Si è quindi potuta valutare l'influenza dei cicli sulle emissioni a caldo ed a freddo e, applicando una delle procedure per la valutazione della sovraemissione a freddo, si sono potute ricavare ulteriori caratteristiche relative al transitorio a freddo per le diverse specie inquinanti regolamentate. Le informazioni sperimentali hanno inoltre consentito lo sviluppo di metodologie statistiche di analisi delle emissioni a caldo e di simulazione del comportamento a freddo. 2 Istituto Motori CNR, viale Marconi, 8-Napoli 1. INTRODUZIONE I veicoli a due ruote rivestono oggi un ruolo di primaria e crescente importanza nell'ambito della mobilità privata, in particolare nel contesto urbano, dove la congestione e le difficoltà di parcheggio giocano un ruolo fondamentale nella scelta della modalità di trasporto. Nel 2009 i mezzi a due ruote circolanti in Europa erano stimati intorno ai 32 milioni e rappresentavano circa l'8% della flotta circolante [1], con quote variabili tra i diversi Paesi in funzione del clima, della conformazione delle città, del tipo di trasporto pubblico locale presente, ecc.. In Italia la percentuale di questi veicoli era pari a circa il 20% del totale della flotta registrata, con una quota di circa 1/3 di ciclomotori (motore con cilindrata inferiore a 50 cm 3) e di 2/3 per i motocicli [2, 3]. Il contributo emissivo dei veicoli a due ruote risulta quindi tutt'altro che trascurabile rispetto a quello delle auto, soprattutto in contesti urbani particolarmente congestionati o dove il clima favorevole consente l'utilizzo di tali mezzi durante l'intero anno, incrementando la quota di moto e ciclomotori realmente circolanti su strada rispetto al totale. Uno studio riferito alla città di Genova tra il 1992 e il 2010 [4] ha stimato il contributo dei motocicli alle emissioni totali di CO ed HC intorno al 38% e 27%, rispettivamente, nell'anno 2010. Gli elementi che rendono critiche queste categorie di veicoli sono le tecnologie di post-trattamento dei gas di scarico, meno efficienti rispetto a quelle delle auto [5, 6] e la scarsa qualità della combustione, non ottimizzata in termini di rapporto aria/combustibile, che è spesso responsabile di alte emissioni di HC e PM [7, 8, 9, 10]. D'altro canto, questi veicoli sono caratterizzati da bassi consumi di combustibile e presentano quindi ridotte emissioni di CO 2 , stimate in Italia intorno al 5% del totale annualmente dovuto ai veicoli stradali [11]. Le emissioni dei veicoli a due ruote nelle aree urbane derivano principalmente dalle condizioni di guida e dalla fase di funzionamento a freddo del motore, che assume fondamentale importanza negli spostamenti brevi, caratteristici di questa tipologia di veicoli [12,13]. Secondo quanto riportato in [14], la differenza tra la modalità di guida urbana ed extraurbana si avverte soprattutto in termini di consumi di combustibile (circa il 30% in più nella prima modalità), mentre la fase di transitorio a freddo causa maggiori emissioni di CO, HC e CO 2 , ulteriormente crescenti al diminuire della temperatura ambiente. Tenendo conto delle precedenti considerazioni, appare evidente come un'accurata valutazione delle emissioni prodotte dai veicoli a due ruote, unitamente alla definizione del loro reale comportamento cinematico, siano di fondamentale importanza nello studio dell'inquinamento da traffico stradale in ambito urbano. A tale scopo, l'Internal Combustion Engines Group (ICEG) dell'Università di Genova e l'Istituto Motori del CNR di Napoli, entrambi impegnati in
... In order to estimate the environmental impact ascribable to road traffic sector and to delineate operative policy to safeguard air quality state in urban contexts, broad investigations are essential for policy makers and academics. In this context, significant publications (European Commission, 2010;Vasic and Weilemann, 2006;Ntziachristos et al., 2006) established that the two-wheelers vehicles in the last years are taking on an increasing chief role in private mobility with an immediate consequence on urban air quality of European countries, and the share of the emissions from mopeds and motorcycles to the total air pollution will increase in the next years if no remedial measures will be taken. ...
In the latest years the effect of powered two-wheelers on air polluting emissions is generally noteworthy all over the world, notwithstanding advances in internal combustion engines allowed to reduce considerably both fuel consumption and exhaust emissions of SI engines. Nowadays, in fact, these vehicles represent common means of quotidian moving, serving to meet daily urban transport necessities with a significant environmental impact on air quality. Besides, the emissive behavior of the two-wheelers measured under fixed legislative driving standards (and not on the local driving conditions) might not be sufficiently representative of real world motorcycle riding.
... This paper is aimed at deepening the knowledge of the effects bioethanol/gasoline fuel blends have when used in a large displacement motorcycle. This topic arises from the need to assess the impact on the urban air quality of two-wheeler class vehicles when used as a means of transport in major cities of southern Europe [8,9]. In Italy, the share of the two-wheelers among the total passenger vehicle fleet is approximately 25% [10,11]. ...
The objective of this study is to investigate the effect of bioethanol–gasoline blends on the exhaust emissions
and engine combustion of a four-stroke motorcycle. Ethanol is known as an alternative fuel for
spark-ignition engines and is suitable for making blends with gasoline, increasing the oxygen content
and decreasing emission of incomplete combustion products. An experimental investigation was performed
on a Euro 3 large-size motorcycle fuelled with commercial gasoline and bioethanol/gasoline
blends (range of bioethanol 5% v to 30% v). Regulated and unregulated emissions and fuel consumption
were quantified over the execution of chassis-dynamometer tests. The combustion analysis, realized by
acquiring the pressure cycle inside the cylinder, highlights the auto adjustment of the engine control unit
and guarantees use within the same parameters of several tested fuels, with the except of fuel injection
time, which increases with increasing ethanol percentage. A significant reduction in carbon monoxide
and particle number is associated with the ethanol content of the fuel. Volatile organic compounds,
mainly alkanes and aromatics, are not substantially influenced by the bioethanol content of the fuel.
The contribution of carcinogenic benzene ranges between 2 and 5%.
... Several attempts have been made to test two-wheeler vehicles and to evaluate their emission profiles (Assamoi & Liousse, 2010;Badami & Iyer, 2006;Gupta, Kothari, Srivastava, & Agarwal, 2010). Vasic and Weilenmann (2006) compared the emissions for different two-wheelers and passenger cars. These researchers compared the emission of CO, HC, NO x , and CO 2 from eight gasoline-powered two-wheelers and seventeen gasoline-powered passenger cars and discovered that the NO x emissions were higher for two-wheelers than for gasoline-powered passenger cars. ...
Two-wheeler vehicles are an important mode of transportation in developing countries. However, the emissions from two-wheeler vehicles are significant. Urban two-wheeler vehicles with gasoline-fueled engines produce NO x and particulate matter emissions that affect urban air quality. During traffic light stops and programmed stops, for instance, pollutants are emitted and are dangerous to human health. In this experimental study, two-wheeler vehicles with different makes, technologies and engine capacities were tested for exhaust emissions including gravimetric and online measurements at different engine speeds and a no load condition at a simulated traffic junction. Gravimetric measurements were performed by collecting the particulate mass (at two engine speeds: 1500 and 2500 rpm) from a diluted engine-out exhaust on quartz filter paper. Next, these collected particulates were used to determine the presence of metals, as well as the benzene soluble organic fraction (BSOF). The total particulate mass, BSOF and trace elements were slightly higher at a higher engine speed (2500 rpm). Online measurements were performed by sampling the engine exhaust (at four engine speeds: 1500, 2000, 2500, and 3000 rpm) and using online instruments to determine the particle number and size distribution, the particle-bound polyaromatic hydrocarbons (PAHs), the gaseous emissions and the smoke opacity. Engines with higher cubic capacity emitted a higher concentration of nano-particles. The particle-bound PAH concentration increased as the engine speed increased, but this concentration was notably low for the highest engine speed tested (3000 rpm). The regulated gaseous emissions increased as the engine speed increased for all vehicles.
... e-mail: jolfert@ualberta.ca There are several studies in the literature about gas phase emissions from 2-stroke and 4-stroke motorcycles and scooters (Prati et al., 2011) and their comparison with passenger vehicles (Vasic et al., 2006), however, their particle emissions behavior, especially in real-time, is not yet fully understood. Nakhawa et al. (2011) measured the particle emissions of ten 4-stroke motorcycles with different engine technologies using Indian driving cycle for two wheeler vehicles. ...
Two wheel vehicles (scooters and motorcycles) make up 74% of the vehicle population in India. An experimental study has been conducted to assess and compare the particulate emissions from several two wheelers and passenger car in a typical Indian fleet. The vehicles, including four 4-stroke, two 2-stroke two-wheelers, and one gasoline-LPG bi-fuel passenger cars, were tested on a chassis dynamometer using the Indian Driving Cycle. A differential mobility spectrometer was employed to measure the particle size distribution in real-time in the range of 5 nm to 560 nm. Particulate size distributions from the two-wheelers were typically bi-modal. The count median diameter with 4-stroke two wheelers was observed in the range of 26 nm to 48 nm. The number and mass emission factors ranged between 9.5 × 1012 km−1 to 1.3 × 1013 km−1 and 0.80 mg/km to 40 mg/km; respectively. In the case of 2-stroke two wheelers, it was observed that not only the count median diameter is 3 times larger compared to 4-strokes, but also 2-stroke vehicles produce 5 times more particles in term of number and about 60 times more particles in terms of mass. The 2-stroke and 4-stroke two wheelers produced particulate emissions (both in terms of number and mass), which were higher than a gasoline and a LPG passenger vehicle operating on the same driving cycle.
... Due to attractive qualities, such as high maneuverability, agility, parking simply, and inexpensive, motorcycles and mopeds are one of the main modes of transportation in major cities in southern Europe, and particularly in Italy where the share of the two-wheelers to the total passenger vehicle fleet is around 25%. Because of their prevailing use in urban environments, emissions of pollutants into atmosphere from two-wheelers are becoming more and more concern, especially for carbon monoxide (CO) and total hydrocarbon emissions (HC) [1,2,3]. ...
The aim of this study is to investigate the effect of ethanol-gasoline mixtures on cold emissive behavior of commercial motorcycles. For the newly sold motorcycles, equipped with a three-way catalyst and electronic mixture control, CO and HC cold additional emissions, if compared with those exhausted in hot conditions, represent an important proportion of total emissions. On the other hand, ethanol is known as potential alcohol alternative fuel for spark ignition engines, which can be blended with gasoline to increase oxygen content and then to decrease emissions. From this explanations, a research on cold start emissions of motorcycles using ethanol-gasoline mixtures was conducted. In this specific study, a motorcycle (belonging to the Euro-3 legislative category) was operated on a chassis dynamometer and driven according to the ECE driving cycle to analyze the exhaust cold extra emissions of CO and HC, while the ethanol was mixed with unleaded gasoline in three different percentages (10, 20 and 30 % v/v). Results of the tests and the application of a calculation procedure, designed to model the cold start transient behavior of motorcycles, indicate that CO and HC cold start extra emissions using ethanol-gasoline blended fuels decrease compared to the use of unleaded gasoline.
Transportation emissions significantly affect human health, air quality, and climate in urban areas. This study conducted experiments in an urban tunnel in Taipei, Taiwan, to characterize vehicle emissions under real driving conditions, providing emission factors of PM2.5, eBC, CO, and CO2. By applying multiple linear regression, it derives individual emission factors for heavy-duty vehicles (HDVs), light-duty vehicles (LDVs), and motorcycles (MCs). Additionally, the oxidative potential using dithiothreitol assay (OPDTT) was established to understand PM2.5 toxicity. Results showed HDVs dominated PM2.5 and eBC concentrations, while LDVs and MCs influenced CO and CO2 levels. The CO emission factor for transportation inside the tunnel was found to be higher than those in previous studies, likely owing to the increased fraction of MCs, which generally emit higher CO levels. Among the three vehicle types, HDVs exhibited the highest PM2.5 and eBC emission factors, while CO and CO2 levels were relatively higher for LDVs and MCs. The OPDTTm demonstrated that fresh traffic emissions were less toxic than aged aerosols, but higher OPDTTv indicated the impact on human health cannot be ignored. This study updates emission factors for various vehicle types, aiding in accurate assessment of transportation emissions' effects on air quality and human health, and providing a guideline for formulating mitigation strategies.
Motorbikes are by far the dominant mode of transportation in Ho Chi Minh City (HCMC). They solve mobility problems but represent a health risk since riders are directly exposed to noxious exhaust fumes. Hence, face masks emerge as a solution to reduce exposure to harmful particles. The manufacturers of these masks report that they can significantly reduce particle exposure on roads with vehicular traffic. Such reports are usually based on laboratory assessments, with limited data from field experiments. To evaluate the performance of the masks commonly worn by HCMC commuters under quasi-real exposure conditions, we tested the total inward leakage of particles (i.e., including penetration through the filter media, and leaks from the face seal and exhalation valve if the mask is equipped with one) of six representative masks mounted on manikins at the curbside of two busy roads during high traffic time periods. Several particle metrics, including mass and number concentrations, active surface area, and abundances of equivalent black carbon and particle-bound polycyclic aromatic hydrocarbons were measured to determine the protection level provided by masks against distinct types of particles. As part of this study, through a set of measurements using the same instrumentation we found that commuters are exposed to a mix of freshly emitted particles and aged particles, including contributions from sources other than motorbike exhaust, such as trash burning and street food stalls. Ultrafine particles, especially those in the nucleation mode (< 50 nm), turned out to be the dominant fraction in terms of number concentration. This study focused its evaluation on these particles. We found that no mask can completely remove all particles under practical conditions. It is largely due to inappropriate mask fitting. Performance efficiency of 60-80% was achieved by an N95 respirator, a reusable valved filtering mask, and a locally manufactured carbon-layer sandwiched mask. Surgical and cloth masks achieved efficiencies of 25-60%. The results show that any face mask provides some level of protection. Efforts should be made to provide end users with practical information on the effectiveness of masks under real conditions, and informing on how to best fit each mask to increase effectiveness.
Large fleets of motorcycle taxis in Kampala, Uganda, and other cities in low and middle-income countries (LMICs) emit significant local and global air pollutants. To reduce emissions, companies have started selling electric motorcycles. We quantify the use-phase emissions impact of electrifying motorcycle taxis by processing real-world trip and charging data from Kampala, then estimating charging-caused emissions with an economic dispatch model of the Ugandan power system. We then compare these emissions to tank-to-wheels estimates of conventional motorcycles over the same trips. We find that electrifying gas-powered motorcycle taxis would reduce carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxide (NOx), and hydrocarbon emissions by 36%, 90%, 58%, and 99%, respectively, but increase sulfur oxide (SOx), particulate matter 10 μm or less (PM10), and particulate matter 2.5 μm or less (PM2.5) emissions by 870%, 109%, and 97%, respectively. PM and SOx emission increases stem from generation at bagasse and heavy fuel oil (HFO) point sources far from load centers. Additionally, we find seasonality of the charging associated emissions due to dominance of hydropower in the Ugandan grid. Overall, we find clear and potential local air pollution benefits of electrifying motorcycle taxis in Kampala.
Nepal is rapidly urbanizing. Until 2014, only 20% of the total population lived in urban areas, but in 2015, over 65% of people were classified as urban dwellers with the promulgation of the constitution of the Federal Republic of Nepal (FRN). Many rural areas are annexed together to meet the population thresholds of some territories in order to classify them as municipals. As of 2017, many of the existing local level political units (which were over 3700) have been combined together reducing the local political units to 753 in total. Until 2014, there were only 105 urban units, but when local political units were decreased to 753 as per the FRN, the number of urban units jumped from 105 to 293 with 276 municipalities, 11 sub-metropolises, and 6 metropolises. However, many of these so classified urban areas are characterized by ruralopolises where people living in rural settings within the legally defined urban areas are competing for the limited facilities of the urban cores. Despite such competition for limited resources/facilities, many of the ruralopolises are aspiring to becoming “smart cities.” However, political leaders and urban planners responsible for the planning of these ruralopolises have been struggling to have real-time geospatial data, one of the essential components of “smart cities.” A “smart city” is an integrated system in which human and social capitals interact, using technology-based solutions. It efficiently achieves sustainable and resilient development and helps maintain a high urban life quality based on a multi-stakeholders’ partnership. The “smart city” initiatives need real-time data that uses auto-sensor state-of-the-art technology. The economic outcomes of a “smart city” initiative results in the simplification of daily working schedules such as bus routing, waste disposal, creation of businesses, jobs, and infrastructure. The brain of a “smart city” includes the virtual real-time data center-fed by an automated sensor network that regulates kiosks, parking meters, cameras, smart phones, medical devices, social networks, and bus routings.
Considering the noble metals resources used in Three-way catalysts are extremely limited, traditional Three-way catalysts can no longer meet the increasingly stringent emissions control standards economically. For more efficient emissions control, we first time to perform a multi-parameters comparative investigation on catalytic converter design for high performance motorcycles with considerations of converter’s structure/size, layout and engine working status under World-wide Motorcycle Test Cycle to explore novel design methods of Three-way catalysts. Based on the several models designed for test, the original transient emissions are measured to explore engine’s working performances and factors that impact raw emissions, the integrated effect of converter structure/size and layout on emissions conversion efficiency is also explored. In this study, Model 1 is double catalytic structure while Model 2 and Model 3 are single structure, detailed parameters about these models are expressed as the format “Length, Diameter or long/short axis for ellipse, Cell density” as: Model 1-front: 42 mm, 123 mm, 200 cpsi; Model 1-rear: 123 mm, 95/65 mm, 300 cpsi; Model 2: 85 mm, 100 mm, 400 cpsi; Model 3: 82 mm, 130 mm, 300 cpsi. Catalytic conversion efficiency of CO, THC and NOx are ranked as Model 3: 88.13% > Model 1: 85.95% > Model 2: 84.89%, Model 1: 93.73% > Model 3: 89.76% > Model 2: 85.79% and Model 1: 98.27% > Model 2: 92.58% > Model 3: 87.05%, respectively. Small-size catalytic converters have quicker warm-up and poorer heat preservation capacity, that’s why Model 2 has the highest catalytic efficiency for CO in cold stage and the lowest overall, Meanwhile, Model 2 has the best trade-off performance. We hope to provide useful knowledge that guides the converter design/application.
In this study, the THC, CO/CO2 and NOx emissions were investigated by experimental measurements on a twin-spark sporting motorcycle under real-world driving. The emissions at two typical engine steady-state operating points were also added for comparison. Meanwhile, the engine working status was monitored during the whole trip. The results indicate that the small throttle opening and the rich air/fuel ratio make the very low engine combustion efficiency during cold-start phase, which leads to higher THC and CO emissions. During this stage, the CO2 is also high due to the absolutely high fuel consumption rather than the high combustion efficiency, due to the low NOx emission. By comparing this studied engine to others, the direction to improve the transient response especially under low loads was found. Compared with steady-state operation, both CO and CO2 during transient driving are lower, because at transient driving the combustion temperature is lower, leading to lower products amounts for those CO precursor (especially for HCO). The lower combustion temperature also leads to lower NOx emission, and the incomplete combustion leads to higher THC emission at cycle driving. In a word, the lower volume efficiency and delay ignition timing result in poorer combustion status during transient driving.
Although not emitting air pollution themselves, cyclists are exposed to air pollution from motorised traffic. Because of the close proximity of mopeds to cyclists, moped emissions may affect cyclist exposure. However, the quantitative contribution of mopeds to cyclists' air pollution exposures is uncertain. The aim of the research was to quantify the contribution of moped emissions to air pollution concentrations on bike lanes.
Measurements of Particle Number Concentrations (PNC),¹ Particulate Matter (PM)² and Black Carbon (BC)³ on bike lanes were performed in September 2016 in four Dutch cities. Passing two- and four-stroke mopeds and other traffic were recorded and distinguished by sound by the trained field worker. One-second PNC, PM and one-minute BC concentrations were measured. Using regression analyses the contribution of passing mopeds to air pollution exposure was analysed.
At 18 non-tunnel locations, two-stroke and four-stroke mopeds contributed at average 12,000 and 3000 pt./cm³ PNC per second when passing by, respectively. In a tunnel, this was 92,000 and 12,000 pt./cm³. Two- and four-strokes added 3 to 19% to total PNC at non-tunnel sites and 58% in a tunnel. Four-strokes caused at average 54% of the contribution of moped emissions to total PNC. At non-tunnel sites, the contribution of mopeds to PM was 1.2 and 0.2 μg/m³ for two- and four-strokes, respectively. In a tunnel this was 3.9 and 2.3 μg/m³. Minute-measurements of BC did not show a relation between mopeds passing by and BC.
Mopeds caused substantial short-term increases in air pollution levels on bike lanes, especially in a tunnel. Two-stroke mopeds caused higher concentration peaks than four-stroke mopeds. The contribution to total air pollution concentrations of four-stroke mopeds was larger, because of the higher share of four-strokes. Because of the close proximity of mopeds to cyclists, cyclists air pollution exposure can be largely influenced by moped emissions.
The gap between certified and real-world passenger vehicle emissions is widening and has driven vehicle policy transitions in the US and in Europe, particularly in the wake of emissions measurement scandals. Since carbon dioxide emissions are highly correlated with fuel consumption (FC), fuel consumption regulation is a useful policy instrument to combat climate change. Although the Chinese government set fuel economy standards in 2004, like many countries it does not conduct testing to confirm real-world FC rates comply with the standards. This paper employs a dataset of real-world FC measurements self-reported by over 1 million vehicle owners in China between 2008 and 2017 through a dedicated mobile phone application. By comparing this user-generated FC data with FC certification, the study provides an indication of discrepancies of FC gap and its characteristics, including: vehicle model year, transmission type, segment, weight bin, and market share. The study finds that while average certified FC decreased by 15% between 2008 and 2017, real-world FC remained unchanged, resulting in FC gap increase from 12% to 30%. The paper concludes that use of a local test-cycle, authoritative data collection, and stronger enforcement, may be useful policy tools for reducing China's real-world vehicle energy consumption.
This paper deals with the in-cylinder flow field analysis in a two-stroke engine under motoring conditions by particle image velocimetry (PIV) and computational fluid dynamics (CFD). The main objective is to analyze the effect of engine parameters viz., engine speed, compression ratio (CR) and port orientation on the in-cylinder flows in a loop-scavenged two-stroke gasoline direct injection (GDI) engine, with an aim to help researchers to design fuel efficient and less polluting two-stroke engines. In this study, a single-cylinder 70 cm3 two-stroke engine which is very commonly used for the two-wheeler application, is considered. The engine cylinder is modified to provide optical access into the in-cylinder region. The PIV experiments are conducted at various engine speeds viz., 500, 1000 and 1500 rev/min, and the plane averaged velocity vector fields obtained, are analyzed to understand the in-cylinder flow behavior. The CFD study is also carried out using the commercial CFD code, STARCD, to study and compare the in-cylinder flow parameters at various engine operating conditions. The CFD results are compared with the experimental results to the extent possible. The CFD predictions are found to be in good agreement with the experimental results. Therefore, the CFD analysis has been extended further to understand the effect of various engine parameters on the in-cylinder flows. We found that the turbulent kinetic energy and tumble ratio increased by about 25% and 20% respectively, when the engine speed was increased from 1000 to 1500 rev/min. Also, we found that the turbulent kinetic energy and tumble ratio decreased by about 13% and 26% when the compression ratio was increased from 7 to 8. In addition, we found that the port orientation, rather than port areas had a greater influence on the in-cylinder flow parameters.
Motorcycles are the third most common means of transportation in the megacity of Tehran. Hence, measurements of emission factors are essential for Tehran motorcycle fleets. In this study, 60 carburetor motorcycles of various mileages and engine displacement volumes were tested in a chassis dynamometer laboratory according to cold start Euro-3 emissions certification test procedures. For almost all of the tested samples, the average carbon monoxide (CO) emission factors were about seven times higher than the limits for Euro-3 certification. No motorcycle fell within the Euro-3 certification limit on CO emissions. 125 cc engine displacement volume motorcycles, which are dominant in Tehran, have the most total unburned hydrocarbons and CO emission rates, and they have less nitrous oxides (NOX) emission rates and fuel consumption compared to those of larger engine volume motorcycles. Calculation of fuel-based emission factors and moles of combustion products shows that about 40% of fuel consumed by 125 cc engine volume motorcycles burns to incomplete combustion products. This proportion is lower for larger engine volume motorcycles. Approximation of relative air–fuel ratio results shows very rich combustion in selected motorcycles. Using a carburetor fuel supply system, low engine compression ratio, aging, and no catalyst could be reasons for high emission rates. These reasons could possibly result in high ultrafine particles emission rates from motorcycles. Comparison of total motorcycle pollutant emissions to that of passenger cars from previous studies in Tehran shows that motorcycles contribute to pollutant much higher than their contribution to the total fleet or total travels.
For the metropolitan setting, we propose the introduction of (mostly) one-seater electric vehicles and a sparse road network dedicated to them. These intelligent commuter vehicles (ICVs) would be bimodal: human-driven on standard roads, and computer-guided in the network (ICVN), which also charges and powers the vehicles. The commuter would drive to the nearest entry/exit terminal, from where the vehicle would be guided to the terminal closest to the destination, the trip being completed by human driving. The sparsity of the network, combined with the vehicles' narrowness and lightness means that it can be constructed relatively painlessly. Network-charging both removes the need of a separate urban charging infrastructure and leads to short range-requirement for the vehicles, hence existing, cheap lead-acid batteries can be used; the controlled environment of the network makes the guiding of the vehicles realizable with existing technology. Hence the paradigm does not need any technological breakthroughs; is backward-compatible, since existing roads are still utilized, and a partlycompleted network can be used; and forward-compatible, since the vehicles can easily be converted to be fully self-driving, if and when we are technologically and socially ready. We believe that these features make the paradigm the most reasonable solution to the metropolitan gridlock problem.
In the urban area the internal combustion engines are the main source of CO2, NOx and particulate matter (PM) emissions. The reduction of these emissions is no more an option, but a necessity highlighted by the even stricter emission standards. In the last years, even more attention was paid to the alternative fuels. They allows both reducing the fuel consumption and the pollutant emissions. With regards to the gaseous fuels, methane is considered one of the most interesting in terms of engine application. It represents an immediate advantage over other hydrocarbon fuels because of the lower C/H ratio. In this paper the effect of the methane on the combustion process, the pollutant emissions and the engine performance was analyzed. The measurements were carried out in an optically accessible single-cylinder, Port Fuel Injection, four-stroke SI engine equipped with the cylinder head of a commercial 250 cc motorcycles engine and fuelled both with gasoline and methane. Optical measurements were performed to analyze the combustion process with a high spatial and temporal resolution. In particular, optical techniques based on 2D-digital imaging were used to follow the flame propagation in the combustion chamber. UV-visible spectroscopy allows detecting the chemical markers of combustion process such as the radicals OH and CH. The exhaust emissions were characterized by means of a gaseous analyzer and an opacimeter. The measurements were performed under steady state conditions, at 2000 rpm at minimum and full load.
Regulated gaseous emissions from two Euro 3 motorcycles and three Euro 5 passenger cars were measured over different driving cycles. The purpose of this study was to get data on typical emission levels and patterns of motorcycles and passenger cars currently circulating on the road in Europe. In respect to this, three driving cycles were selected: the current type approval driving cycles used to certify the test vehicles for emissions (NEDC for passenger cars and the EDC for motorcycles) and the world-wide harmonized driving cycle for motorcycles (WMTC). The gaseous emissions (NOx, HC, CO and CO 2) were measured using the typical type approval test procedure for light duty vehicles. Since all the vehicles tested had been certified using the relevant current legislative cycle (i.e. NEDC or EDC), these vehicles were presumably not optimized for the WMTC cycle. This means that the emissions measured over the WMTC may be considered closer to real world driving emissions allowing a more realistic comparison between the tested passenger cars and motorcycles. In addition to the emission bag-values, the second-by-second emission concentration values measured at the tailpipe outlet were recorded, allowing the analysis of the emission patterns and in particular of the importance of the cold start in respect to the distance specific emissions. In general, HC and CO emissions from the tested motorcycles resulted to be higher than the respective emission levels of the passenger car, while NOx emissions resulted to be dependent on the engine technology.
This book is a comprehensive and objective guide to understanding hydrogen as a transportation fuel. The effects that pursuing different vehicle technology development paths will have on the economy, the environment, public safety and human health are presented with implications for policy makers, industrial stakeholders and researchers alike. Using hydrogen as a fuel offers a possible solution to satisfying global mobility needs, including sustainability of supply and the potential reduction of greenhouse gas emissions. This book focuses on research issues that are at the intersection of hydrogen and transportation, since the study of vehicles and energy-carriers is inseparable. It concentrates on light duty vehicles (cars and light trucks), set in the context of other competing technologies, the larger energy sector and the overall economy. The book is invaluable for researchers and policy makers in transportation policy, energy economics, systems dynamics, vehicle powertrain modeling and simulation, environmental science and environmental engineering.
In all the world mopeds and motorcycles are popular means of daily moving, helping to meet daily urban transport needs, as a consequence two-wheelers contribution to air pollution is generally significant, especially in urban environment. Emission models commonly used in Europe, are based mainly on the average trip speed to predict emissions, thus they are not sensitive to variations of vehicles instantaneous speed and acceleration, which have a strong effect on emissions and fuel consumption; besides these models do not analyze in depth the cold emissive behaviour of motorcycles. An expansion of the two-wheelers emission database was deemed necessary. This study is aimed at the examination of the emissions of in-use motorcycles during real driving conditions, contributing significantly to extend the knowledge of two-wheeler emission behaviour. For this purpose, an experimental investigation was realized by the Department of Mechanic and Energetic (DiME) of the University of Naples: emissions of regulated pollutants (CO, HC and NOX) were evaluated in the exhaust of one scooter belonging to the Euro-3 legislative category, equipped with catalytic converter, and with a displacement of 300 cm 3. In order to evaluate the performance of this motorcycle under real-world motorcycle riding, in cold and hot conditions, sampling was achieved on a dynamometer bench during both the Type Approval driving cycle and real-world driving cycles, also by employing the instantaneous emission results. The experimental data and the statistical processing results of this research are compared with current emission models for calculating emissions from road traffic.
The small engine for two-wheel vehicles has generally high possibility to be optimized at low speeds and high loads. In these conditions fuel consumption and pollutants emission should be reduced maintaining the performance levels. This optimization can be realized only improving the basic knowledge of the thermo-fluid dynamic phenomena occurring during the combustion process. It is known that, during the fuel injection phase in PFI SI engines, thin films of liquid fuel can form on the valves surface and on the cylinder walls. Successively the fuel films interact with the intake manifold and the combustion chamber gas flow. During the normal combustion process, it is possible to achieve gas temperature and mixture strength conditions that lead to fuel film ignition. This phenomenon can create diffusion-controlled flames that can persist well after the normal combustion event. These flames induce the emission of soot and unburned hydrocarbons. In this paper, experimental activities were carried out in the combustion chamber of a single-cylinder 4-stroke optical engine. The engine was equipped with a four-valve head of a commercial Piaggio engine for 2-wheel vehicle. Two injectors were tested: standard 3-hole injector and 10-hole injector for multi-cylinder engine of a passenger car. High spatial resolution digital imaging was used to characterize the flame propagation. The presence of diffusion-controlled flames near the valves and on the cylinder walls was investigated. The flames induced the formation of unburned hydrocarbons and soot particles. The in-cylinder optical investigations were correlated with particulate emissions. The effect of three-way catalyst on the exhaust particles was examined.
The increasing urbanization level of many countries around the globe has led to a rapid increase of mobility demand in cities. Although public transport may play an important role, there are still many people relying on private vehicles, and, especially in urban areas, motorcycles and scooters can combine handling and flexibility with lower cost of operation compared to passenger cars. However, in spite of their lower fuel demand, they might significantly contribute to air pollution, lagging behind cars in terms of emission performances. The aim of this paper is to provide the scientific community with the results of an exploratory test campaign on four different motorcycles, converted from gasoline to CNG by means of an after-market conversion kit. A fifth motorcycle, similarly converted from gasoline to LPG, was also tested. These vehicles are powered by 4-strokes engines with a displacement ranging from 50 to 250 cm3 and a power ranging from 3.0 to 16.5 kW. They have been tested over the relevant phases of the ECE-47, ECE-40 and WMTC driving cycles, with both gasoline and gaseous fuel. Gaseous emissions results show the dependence of HCs, CO, CO2, NOx and CH4 on the engine displacement, fuel, injection and catalyst technology. Additionally the energy efficiency and the environmental impact of the different tested configurations have been analyzed in terms of equivalent energy consumption and GWP. The results suggest that the CNG fuel with the appropriate injection technology might be a viable solution to combine low cost of operation with low gaseous emissions and global warming impact. The tests underline the need of an optimized setup of the conversion kit to avoid unwanted increase of the emissions.
This paper aims to investigate the sudden growth of motorization in
Brazil with regard to motorcycles and similar motorized vehicles in
order to show that this increase is a function of their use in activities
motorcycle taxi and motor freight. These classes enhance the use of
this type of transport, not only in terms of pleasure, but in order to
meet the needs of a new labor category, generating employment
and income.
The tail-pipe emissions of carbon monoxide (CO), nitrogen oxides (NOx), total hydrocarbons (THC), and speciated volatile organic compounds (VOCs) from the exhausts of cars and motorcycles with and without catalysts in the Federal Test Procedures (FTP) and European Community Emission (ECE) driving cycles were measured and compared. Compared with catalyst cars, motorcycles were found to emit 12 times as much THC and CO for every kilometer driven. Cars and four-stroke motorcycles emitted much higher levels of NOx than two-stroke motorcycles. Motorcycle emission rates of benzene were lower than those from noncatalyst cars but higher than those from catalyst cars. The catalyst’s reduction efficiency in motorcycles was only one-half that in cars. Among the exhaust components, the reduction efficiencies of aromatics were lower than those of THC and CO by the catalysts. For most pollutants, the greatest reduction of emissions by the catalysts occurred in Phase 2 of the FTP driving cycle. In this study, the VOC profiles in the emissions were found to be relatively rich in benzene.
The emissions of carbon monoxide (CO), nitrogen oxides (NOx) and total hydrocarbon (THC) from 7 new and 12 in-use motorcycles with or without the catalyst were evaluated by testing these vehicles on a dynamometer. Also the concentrations of volatile organic compounds (VOCs) in five driving patterns, including idle, acceleration, 30 km h−1 cruise, 50 km h−1 cruise, and deceleration, were monitored.Experimental results indicate that the emissions of CO and THC from in-use motorcycles are significantly higher than new ones, but not for NOx, and the emissions of THC from 2-stroke motorcycles are much higher than 4-stroke ones. The emissions of VOCs from in-use motorcycles are higher than new motorcycles for all five driving patterns, and those from 2-stroke engines are higher than 4-stroke motorcycles. Emission of VOCs in the modes of deceleration and idle accounts for the most mass emitted during the test driving cycle.
This study surveyed emissions from 2- and 4-stroke new and in-use motorcycles. Emission tests were carried out on a dynamometer following the designated test procedure of the Economic Commission for Europe (ECE). Samples were derived during various driving stages, which included idle, acceleration, 30 km/hr cruise, 50 km/hr cruise, and deceleration. All test motorcycles (10 new and 15 in-use) complied with Taiwan Environmental Protection Administration's Phase III Motorcycle Emission Standards. The dominant volatile organic carbon (VOC) species were isopentane (53 and 295 mg/km, 2- and 4-stroke, respectively), 2-methylpentane (75 and 83 mg/km), 3-methylpentane (34 and 66 mg/km), and toluene (30 and 100 mg/km). The VOC emission factors for the 2-/4-stroke motorcycles were 311/344 (new) and 1479/433 (in-use) mg/km, respectively. In addition, the dominant carbonyl species for the new and in-use motorcycles were formaldehyde (0.4 and 0.7 mg/km, respectively), acetaldehyde (0.6 and 1.2 mg/km), and acetone (0.5 and 0.7 mg/km). The carbonyl compound emission factors for the 2- and 4-stroke motorcycles were 3.2/3.1 (new) and 5.3/4.6 (in-use) mg/km, respectively. The ozone formation potentials, based on an ECE test cycle, show that the values from the in-use motorcycles were higher than those from the new motorcycles. The dominant VOC species for the ozone formation potential were propylene (65 and 502 mg-O3/km, respectively), isopentane (98 and 501 mg-O3/km), 2-methylpentane (152 and 167 mg-O3/ km), 3-methylpentane (79 and 253 mg-O3/km), and toluene (127 and 398 mg-O3/km). Further, the dominant carbonyl species were formaldehyde (4.1 and 6.2 mg-O3/ km, new and in-use, respectively) and acetaldehyde (4.8 and 9 mg-O3/km).
This work reports sampling of motorcycle on-road driving cycles in actual urban and rural environments and the development of representative driving cycles using the principle of least total variance in individual regions. Based on the representative driving cycles in individual regions, emission factors for carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NO(x)=NO+NO(2)) and carbon dioxide (CO(2)), as well as fuel consumption, were determined using a chassis dynamometer. The measurement results show that the representative driving cycles are almost identical in the three largest cities in Taiwan, but they differ significantly from the rural driving cycle. Irrespective of driving conditions, emission factors differ insignificantly between the urban and rural regions at a 95% confidence level. However, the fuel consumption in urban centers is approximately 30% higher than in the rural regions, with driving conditions in the former usually poor compared to the latter. Two-stroke motorcycles generally have considerably higher HC emissions and quite lower NO(x) emissions than those of four-stroke motorcycles. Comparisons with other studies suggest that factors such as road characteristics, traffic volume, vehicle type, driving conditions and driver behavior may affect motorcycle emission levels in real traffic situations.
Towards meaningful real-world emission factors for motorcycles: An evaluation of several recent TNO projects
- R Gense
- D Elst
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Nachfü hrung der Emissionsgrundlagen Strassenverkehr, Messungen 01-02, Benzinpersonenwagen Euro-0 und Euro-3 sowie Dieselpersonenwagen Euro-2
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Luftschadstoff-EmissionendesStrassenverkehrs1980- 2030 BUWAL (Swiss Agency for the Environment, Forests and Landscape
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Real-world driving cycles for emission measurements: ARTEMIS and Swiss cycles. BUWAL SRU Nr. 255: Bern, 2001. (6) WMTC. Worldwide Harmonized Motorcycle Emissions Certifica-tion Procedure; United Nations Economic Commission for Europe
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Swiss Governement, EDMZ 1988-763: Bern, 1988. (4) ARTEMIS, Assessment and reliability of transport emission models and inventory systems; A project within the 5th EU Frame Program
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EMPA: Dü bendorf Emission Stability; Artemis 3122 report Vehicles Sampling Methods for Emission Measure-ment; Artemis 3131 report, Inrets report no LTE 0228 Volatile organic profiles and photochemical potentials from motorcycle engine exhaust
- M Weilenmann
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- M Zallinger
- J.-M André
Weilenmann, M. Nachfü hrung der Emissionsgrundlagen Strassenverkehr, Mes-sungen 01-02, Benzinpersonenwagen Euro-0 und Euro-3 sowie Dieselpersonenwagen Euro-2; EMPA report 202114; EMPA: Dü bendorf, 2004. (10) Hausberger, S.; Wiesmayr, J.; Zallinger, M. Emission Stability; Artemis 3122 report; Technical University Graz, 2004. (11) André, J.-M. Vehicles Sampling Methods for Emission Measure-ment; Artemis 3131 report, Inrets report no LTE 0228; Lyon-Bron, 2002. (12) Tsai, J. H.; Liu, Y. Y.; Yang, C. Y.; Chiang, H. L.; Chang, L. P. Volatile organic profiles and photochemical potentials from motorcycle engine exhaust. J. Air Waste Manage. Assoc. 2003, 53 (5), 516-522.
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Artemis 3122 report; Technical University Graz, 2004.
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