Emissions of currently non-regulated gaseous pollutants from modern passenger cars

The current vehicle type approval regulation in Europe controls specific exhaust gas constituents, while additional species may prove harmful for the environment and human health. This paper presents emission results of currently non-regulated gaseous pollutants from passenger cars. To this aim, four cars of different powertrain and exhaust aftertreatment technologies have been tested in a wide range of conditions. Ammonia (NH3), nitrous oxide (N2O) and methane (CH4) were included in the measurements, together with the currently regulated gaseous pollutants. The results showed that NH3 forms in the three-way catalyst (TWC) in harsh accelerations, while CH4 is the main hydrocarbon emitted by natural gas and diesel vehicles, the latter equipped with lean NOx trap. In spark-ignition engines, N2O formation was observed during the warm-up period of the TWC

Measuring Automotive Exhaust Particles down to 10 nm

The latest generation of internal combustion engines may emit significant levels of sub-23 nm particles. The main objective of the Horizon 2020 "DownToTen"project was to develop a robust methodology and provide policy recommendations towards the particle number (PN) emissions measurements in the sub-23 nm region. In order to achieve this target, a new portable exhaust particle sampling system (PEPS) was developed, being capable of measuring exhaust particles down to at least 10 nm under real-world conditions. The main design target was to build a system that is compatible with current PMP requirements and is characterized by minimized losses in the sub-23 nm region, high robustness against artefacts and high flexibility in terms of different PN modes investigation, i.e. non-volatile, volatile and secondary particles. This measurement setup was used for the evaluation of particle emissions from the latest technology engine and powertrain technologies (including vehicles from other Horizon 2020 projects), different fuel types, and a wide range of exhaust aftertreatment systems. Results revealed that in most cases (non-volatile), PN emissions down to 10 nm (SPN10) do not exceed the current SPN23 limit of 6×1011 p/km. However, there are some cases where SPN10 emissions exceeded the limit, although SPN23 were below that. An interesting finding was that even in the latter cases, the installation of a particle filter could significantly reduce PN emissions across a wide particle size range, fuels, and combustion technology. DownToTen results are being used to scientifically underpin the Euro 7/VII emission standard development in the EU. The method developed and the results obtained may be used to bring in the market clean and efficient vehicle technologies, improve engine and emission control performance with different fuels, and characterize size-fractionated particle chemistry to identify the formation mechanisms and control those in a targeted, cost-effective fashion.acceptedVersionPeer reviewe

Perspectives for regulating 10 nm particle number emissions based on novel measurement methodologies

Concerns regarding noxious emissions from internal combustion engines have increased over the years. There is a strong need to understand the nature of sub-23 nm particles and to develop measurement techniques to evaluate the feasibility of new regulations for particle number emissions in the sub-23 nm region (down to at least 10 nm). This paper presents the results of three EU-funded projects (DownToTen, PEMs4Nano and SUREAL-23) which supported the understanding, measurement and regulation of particle emissions below 23 nm and have successfully developed sub-23 nm particle measurement devices, specifically laboratory systems and mobile devices for RDE tests. The new technology was validated in chassis dyno tests and on the real road. The results show that sub-23 nm particles are mainly generated at the engine start and during acceleration phases. The innovations show that the technology is mature and robust enough to serve as a basis for regulating sub-23 nm particles.The DownToTen project has received funding from the European Union's Horizon 2020 research and innovation programme under agreement No 724085. The PEMs4Nano project has received funding from the European Union's Horizon 2020 research and innovation programme under agreement No 724145. The SUREAL-23 project has received funding from the European Union's Horizon 2020 research and innovation programme under agreement No 724136