Real Driving Emissions: 2017 Assessment of PEMS measurement uncertainty

Regulation 2016/427 introduced on-road testing with Portable Emissions Measurement Systems (PEMS) to complement the laboratory Type I test for the type approval of light-duty vehicles in the European Union. A NOx conformity factor of 1.5 will apply from January 2020/2021. This conformity factor includes a margin of 0.5 to account for the additional measurement uncertainty of PEMS relative to standard laboratory equipment. Said margin (and also the PN margin, initially set at 0.5 by Regulation (EU) 2017/1154 (RDE3), has to be reviewed annually (Recital 10 of Regulation 2016/646). This report summarizes the first review of the NOx margin and lays out the framework for future margin reviews. Since the PN margin was first set in 2017, it was not included in the 2017 review exercise. Based on experimental data received by the stakeholders, technical improvements of PEMS and assumptions of possible zero drift during the tests, a NOx margin of 0.24 to 0.43 was calculated.JRC.C.4-Sustainable Transpor

Impact of fuels and exhaust aftertreatment systems on the unregulated emissions from mopeds, light and heavy-duty vehicles

Transport sector plays a key role in climate change and air pollution. Among the anthropogenic sectors, on-road transport is recognized as the rst contributor to global warming, mainly due to its emission of carbon dioxide, ozone precursors and carbonaceous aerosols. In addition, on-road transport contributes to the deterioration of air quality by releasing nitrogen oxides, hydrocarbons, carbonyls, ammonia, and aerosols. However, the current European legislation of vehicles emissions focusses on a limited number of pollutants, namely hydrocarbons, carbon monoxide, nitrogen oxides, and particulate matter. The aim of this work was to improve the knowledge about the emission factors of gas phase and particle-associated emissions from vehicle exhaust. The impacts of aftertreatment devices and fuel quality on regulated and un- regulated species were studied. Several sampling campaigns with dierent types of vehicles were conducted in the vehicle emission laboratory (VELA) at the European Commission Joint Research Centre (EC-JRC) Ispra, Italy. The vehicles chosen were representative of some categories circulating in Europe (heavy duty vehicles, light duty vehicles, two-stroke mopeds), and either standard fuel or some alternative fuels (ethanol and liqueed petroleum gas) were used. The gas phase was monitored by a Fourier transform in- frared spectrometer (carbonyls, nitrogen-containing species, small hydro-carbons), and a resonance-enhanced multiphoton ionization time-ofightmass spectrometer (mono and polycyclic aromatic hydrocarbons). The particulate phase was analyzed by a high-resolution time-of- ight aerosol mass spectrometer (organic aerosol, chloride, nitrate), and a multiangle absorption photometer (black carbon). The mopeds were found to have the higher emission factors of primary organic aerosol and polycyclic aromatic hydrocarbons. While ecient to reduce the regulated emissions, the after-treatment used to comply with the moped Euro 2 emission standard might be responsible of large emission of unregulated organic aerosols. Most of the emission linked to the gasoline light duty vehicles were released before the light-o of the catalyst. Whereas alternative fuels studied helped to reduce ozone precursor emissions, the pollutants associated to the cold start of the vehicle reduced this benecial eect. Finally, the heavy duty diesel vehicle featured the highest nitrogen oxides and black carbon emissions. Despite ecient retrot and after-treatment systems (for particles and nitrogen oxides), these vehicles could release signicant amount of ammonia. These results provided valuable insights for the drafting of legislation related to the achievement of sustainable transport in Europe. Keywords: Atmospheric pollution; on-road transport; unregulated emis- sions; alternative fuels; exhaust aftertreatment systems; mopeds.JRC.F.8-Sustainable Transpor

Intercomparison of real-time tailpipe ammonia measurements from vehicles tested over the new world-harmonized light-duty vehicle test cycle (WLTC)

Four light duty vehicles (two diesels, one flex-fuel and one gasoline vehicle) were tested as part of an intercomparison exercise of the World harmonized Light-duty vehicle Test Procedure (WLTP) aiming at measuring real-time ammonia emissions from the vehicles’ raw exhaust at the tailpipe. The tests were conducted in the Vehicle Emission Laboratory (VELA) at the European Commission Joint Research Centre (EC-JRC) Ispra, Italy. HORIBA, CGS and the Sustainable Transport Unit of the JRC, took part in the measurement and analysis of the four vehicles exhaust emissions over the World harmonized Light-duty vehicle Test Cycle (WLTC) class 3, version 5.3 using a HORIBA MEXA 1400 QL-NX, a CGS BLAQ-Sys and the JRC FTIR, respectively. The measured ammonia concentrations and the emission profiles revealed that these three instruments are suitable to measure ammonia from the vehicles raw exhaust, presenting no significant differences. Furthermore, results showed that measurement of ammonia from the vehicle exhaust using online systems can be performed guaranteeing the reproducibility and repeatability of the results. While no ammonia was detected for any of the two diesel vehicles (even though, one was equipped with a SCR system) average ammonia emission factors 8-10 mg/km (average concentrations 20-23 ppm) and 10-12 mg/km (average concentrations 22-24 ppm) were estimated for the flex-fuel and gasoline vehicles, respectively.JRC.F.8-Sustainable Transpor

Joint Research Centre 2017 light-duty vehicles emissions testing

This report summarises the results of the pilot study on the market surveillance of light-duty vehicles. The emission performance and the CO2 emissions of 15 vehicles are presented. The methodology for vehicle compliance checks defined in the Guidance note published by the European Commission was applied and discussed.JRC.C.4-Sustainable Transpor

On-road emissions and energy efficiency assessment of a plug-in hybrid electric vehicle

In order to assess potential benefits brought by the electrification of transport it becomes more and more important to evaluate the performance of hybrid electric vehicles (HEVs) in real-driving conditions, measuring on-road air pollutant emissions and energy efficiency. The present report describes a portable system used at JRC for e-measurements in hybrid and electric vehicles, as an upgrade of the classic PEMS (Portable Emission Measurement System). Preliminary results of a test campaign conducted on a Euro-6 Plug-in Hybrid Passenger Car (PHEV) equipped with a Flywheel Alternator Starter (FAS) are reported. The influence of different driving modes as well as of different initial battery state of charge on CO2 and NOx emissions and energy consumption has been evaluated.JRC.C.4-Sustainable Transpor

Secondary organic aerosol formation from gasoline vehicle emissions in a new mobile environmental reaction chamber

We present a new mobile environmental reaction chamber for the simulation of the atmospheric aging of different emissions sources without limitation from the instruments or facilities available at any single site. Photochemistry is simulated using a set of 40 UV lights (total power 4 KW). Characterisation of the emission spectrum of these lights shows that atmospheric aging of emissions may be simulated over a range of temperatures (-7 to 25°C). A photolysis rate of NO2, JNO2, of (8.0±0.7)×10-3 s-1 was determined at 25°C. We demonstrate the utility of this new system by presenting results on the aging (OH=12×106 cm-3h) of emissions from a modern (Euro 5) gasoline car operated during a driving cycle (New European Driving Cycle, NEDC) on a chassis dynamometer in a vehicle test cell. Emissions from the entire NEDC were sampled and aged in the chamber. A thorough investigation of the composition of the gas phase emissions suggests that the observed SOA is from previously unconsidered precursors and processes. This large enhancement in PM mass from gasoline vehicle aerosol emissions due to SOA formation, if it occurs across a wider range of gasoline vehicles, would have significant implications for our understanding of the contribution of on-road gasoline vehicles to ambient aerosols.JRC.F.8-Sustainable Transpor

On-road vehicle emissions beyond RDE conditions

Passenger cars are an important source of air pollution, especially in urban areas. Recently, real-driving emissions (RDE) test procedures have been introduced in the EU aiming to evaluate nitrogen oxides (NOx) and particulate number (PN) emissions from passenger cars during on-road operation. Although RDE accounts for a large variety of real-world driving, it excludes certain driving situations by setting boundary conditions (e.g., in relation to altitude, temperature or dynamic driving). The present work investigates the on-road emissions of NOx, NO2, CO, particle number (PN) and CO2 from a fleet of nineteen Euro 6b, 6c and 6d-TEMP vehicles, including diesel, gasoline (GDI and PFI) and compressed natural gas (CNG) vehicles. The vehicles were tested under different on-road driving conditions outside boundaries. These included ‘baseline’ tests, but also testing conditions beyond the RDE boundary conditions to investigate the performance of the emissions control devices in demanding situations. Consistently, low average emission rates of PN and CO were measured from all diesel vehicles tested under most conditions. Moreover, the tested Euro 6d-TEMP and Euro 6c diesel vehicles met the NOx emission limits applicable to Euro 6d-TEMP diesel vehicles during RDE tests (168 mg/km). The Euro 6b GDI vehicle equipped with a gasoline particulate filter (GPF) presented PN emissions < 6×1011 #/km. These results, in contrast with previous on-road measurements from earlier Euro 6 vehicles, indicate more efficient emission control technologies are currently being used in diesel and gasoline vehicles. However, the results described in this report also raise some new concerns. In particular, the emissions of CO (measured during the regulated RDE test, but without an emission limit associated to it) or PN from PFI vehicles (presently not covered by the Euro 6 standard) showed elevated results in some occasions. Emissions of CO were up to 7.5 times higher when the more dynamic tests were conducted and the highest PN emissions were measured from a PFI gasoline vehicle during dynamic driving. The work also investigates how NOx, CO, PN and CO2 on-road emissions from three vehicles are impacted by sub-zero ambient temperatures and high altitudes. Two of the tested vehicles were Euro 6d-TEMP certified vehicles, one diesel and one gasoline, and one was a Euro 6b plug-in hybrid vehicle. The vehicles were studied during tests that do not fulfil the boundary conditions in terms of maximum altitude, altitude gain, and/or minimum temperature. The obtained emissions were compared to those obtained during tests performed along RDE routes. The results indicate that cold ambient temperature and high altitude, outside the RDE boundary conditions, lead to in higher NOx, CO and PN emissions compared to moderate conditions of temperature and altitude. Nonetheless, the two Euro 6d-TEMP vehicles tested in those extreme conditions yielded NOx emissions factors that fulfilled the Euro 6d-TEMP emission requirements. Our work underlines the importance of a technology- and fuel-neutral approach to vehicle emission standards, whereby all vehicles must comply with the same emission limits for all pollutants.JRC.C.4-Sustainable Transpor

Two-stroke scooters are a dominant source of air pollution in many cities.

Fossil fuel-powered vehicles emit significant particulate matter, for example, black carbon and primary organic aerosol, and produce secondary organic aerosol. Here we quantify secondary organic aerosol production from two-stroke scooters. Cars and trucks, particularly diesel vehicles, are thought to be the main vehicular pollution sources. This needs re-thinking, as we show that elevated particulate matter levels can be a consequence of 'asymmetric pollution' from two-stroke scooters, vehicles that constitute a small fraction of the fleet, but can dominate urban vehicular pollution through organic aerosol and aromatic emission factors up to thousands of times higher than from other vehicle classes. Further, we demonstrate that oxidation processes producing secondary organic aerosol from vehicle exhaust also form potentially toxic 'reactive oxygen species'.This work was supported by the Swiss Federal Office for the Environment (FOEN), the Federal Roads Office (FEDRO), the Swiss National Science Foundation (Ambizione PZ00P2_131673, SAPMAV 200021_13016), the EU commission (FP7, COFUND: PSI-Fellow, grant agreement n.° 290605), the UK Natural Environment Research Council (NERC), the French Environment and Energy Management Agency (ADEME, Grant number 1162C00O2) and the Velux Foundation.This is the accepted manuscript version. The final version is available from http://www.nature.com/ncomms/2014/140513/ncomms4749/full/ncomms4749.html

An assessment of how bio-E10 will impact the vehicle-related ozone contamination in China

Bio-E10 is short for the biofuel made up of 90% gasoline in volume and 10% bio-ethanol, which is the ethanol made from commercially-grown crops such as corn and wheat by the sugar fermentation process. In China, bio-E10 will be supplied nationwide from 2020 as an alternative to conventional gasoline, aiming at ensuring greater energy security and lowering the greenhouse gas emissions. In order to assess the impacts of the upcoming bio-E10 application on the ozone forming potential (OFP) of the emissions from in-use vehicles, this paper examined the carbonyls and volatile organic compounds (VOCs) in the evaporative and tailpipe emissions of three China-4 certified in-use vehicles fueled with a market-available gasoline and two match-blend bio-E10s, and calculated their OFPs using the Maximum Incremental Reactivity (MIR) method. The results revealed that for the evaporative emissions, the use of bio-E10s increased the carbonyl and VOC emissions released within the diurnal-loss stage by 8.5–17.6% and 11.1–78.6% respectively, but decreased the carbonyl and VOC emissions in the hot-soak stage by 47.4%–61.5% and 4.8%–20.6% respectively. Regarding the tailpipe emissions, in comparison to the gasoline baseline, burning bio-E10s increased the carbonyls by 15%–46% while reducing the VOCs by 37%–56% over the New European Driving Cycle (NEDC). Reductions in the tailpipe OFPs up to 47.3% were seen with the application of the bio-E10s, however, there were no clear conclusions with respect to the evaporative OFPs, which varied from −15% to ＋25% compared to the gasoline baseline. Based on the test results and census data, the application of bio-E10 in China is shown to help remove part of ozone contamination from the in-use vehicle sector