Comparison of regulated emission factors of Euro 6 LDV in Nordic temperatures and cold start conditions: Diesel- and gasoline direct-injection

Christian Weber,Ingrid Sundvor,Erik Figenbaum

doi:10.1016/j.atmosenv.2019.02.031

Christian Weber, Ingrid Sundvor + Show 1 more

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https://doi.org/10.1016/j.atmosenv.2019.02.031

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Journal: Atmospheric Environment	Publication Date: Mar 5, 2019
Citations: 50	License type: cc-by

Affiliation: Institute of Transport Economics

Abstract

Local air pollution in Norwegian wintertime is characterized by an increase in NO2 concentrations, due to poor dispersion and increased vehicle emissions. The focus of this study is therefore the characterisation of exhaust vehicle emissions in cold ambient temperatures. Euro 6 Gasoline Direct Injection (GDI) cars and diesel cars were tested in the laboratory in cold temperatures, including with cold start of the engine. Results show high emissions of CO2, PM and NOx. For the first time, we report also elevated NOx values for GDI vehicles. Further measurements are required to investigate whether these results are the beginning of a new trend of high NOx emissions from GDIs, or if these results represent singular events, but it may indicate that further NOx traps or catalysts are required for these vehicles. Understanding the relationship of cold ambient temperatures and vehicle emissions is also particularly important for air quality dispersion modelling, which do not currently account for emission temperature dependence.

Highlights

Local air pollution is a persistent problem all over Europe (Air quality in Europe, 2017, 2017)
Euro 6 Gasoline Direct Injection (GDI) cars and diesel cars were tested in the laboratory in cold temperatures, including with cold start of the engine
Further measurements are required to investigate whether these results are the beginning of a new trend of high NOx emissions from GDIs, or if these results represent singular events, but it may indicate that further NOx traps or catalysts are required for these vehicles

Summary

Introduction

Local air pollution is a persistent problem all over Europe (Air quality in Europe, 2017, 2017). In Norway, air pollution is mainly noticeable during wintertime due to poorer dispersion conditions. These occasional episodes with long-lasting temperature inversions create a build-up of pollution (Ødegaard et al, 2010), which may lead to violations of air quality regulations. Winter conditions pose an additional challenge for air quality, since vehicle starts in ambient temperatures (’cold starts’) cause increased exhaust emissions from internal combustion engine vehicles at low temperatures. Norway follows European Union (EU) legislation on vehicle emissions, through which few exhaust components (hydrocarbons and CO) have been regulated for emission in cold temperatures. The knowledge basis for estimating the extra cold temperature emission contribution for NOx and particulate matter (PM), as well as particulate number (PN), has been limited (Dardiotis et al., 2013).

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Conclusion