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Partikeludslip fra nye tunge køretøjer (Euronorm IV og V) 2 Summary and conclusions2.1 BackgroundThe new Danish act on environmental zones allows local authorities to define zones where EURO III or older heavy duty vehicles should be equipped with a particulate filter. The introduction of EURO IV and V has reduced particulate emissions from heavy duty vehicles by approximately 80 % based on the mass of particles. There is, however, substantial uncertainty about the impact on the number of ultrafine particles, since they are not covered by Euronorm standards. When passing the bill, the Danish Minister for the Environment of the time stated that all relevant knowledge about particle emission from heavy duty vehicles needed to be collected for subsequent publication. To this end, the Danish Environmental Protection Agency (DEPA) commissioned a literature survey. The purpose of the the survey is to provide an overview of the latest knowledge in the field of particle emissions from heavy duty vehicles, with special focus on the average size of the particle emissions. Another objective of study is to analyse the direct emissions of NO2 from heavy duty vehicles classified under EURO IV and V. 2.2 The SurveyThe survey is based on the contributions of 11 persons, all of whom were contacted by email and asked to contribute relevant information and literature about NO2 and particle emissions from heavy duty vehicles. The result was approximately 60 titles on related topics. The 60 articles were screened for relevance in terms of particle size, relevant Euronorm standards and NO2-emissions information. Only three articles were found to be relevant for the study. The three articles form the basis for the assessment of ultrafine particle emissions from EURO IV and V heavy duty vehicles. The extensive literature survey only found three relevant studies:
The report by R. Carbone is part of the deliverables for the Particulates project, and Andreas Mayer's survey was known to DEPA already before the present study was initiated. However, since the literature retrieval involved a large number of well-known experts within the subject field, it is reasonable to assume that no new knowledge is available. However, new knowledge may be in the process of being accumulated. Prof. Stefan Hausberger, TU Graz, Austria informed the project team that TU Graz together with Empa in Switzerland are working on a project on ultrafine particulate emissions from EURO IV and V heavy duty vehicles. 2.2.1 R. Carbone, et al. (2005): (CONCAWE/Particulates)The purpose of the Particulates project was to estimate the fuel impact on particle emissions from new engines and technologies. The project measured emissions from three types of engines with several types of fuel. The EURO IV and V technologies were prototypes. These technologies were not at the market at the time of the measurements. The prototype EURO-IV was designed using a combination of EGR and CRT (i.e. with particulate filter). The solution may be less relevant today, since it never really gained a foothold on the market. The prototype EURO V was designed using a SCR-urea system and is expected to become the general solution in the future. As part of the project, particle mass (PM) and total number of particles, particle surface area, number of carbonaceous particles and size distribution were measured. The results of the measurements were that the particle mass was reduced substantially with EURO IV and V cleaning technologies. In terms of number of particles, measurements showed that the EURO IV technology reduces the number of particles significantly. However, this was to be expected given the fact that the EURO IV cleaning technology applied in the study used a proper particle filter. The EURO V SCR/urea reduction technology brought about a reduction of approximately 70 % in carbonaceous particles. It is estimated that well-known state-of-the-art measurement methods, driving cycles etc. were applied. The results seem robust with respect to EURO V. However, this is not the case with EURO IV since the EURO IV prototype used in the study is not on the market today. 2.2.2 Andreas MayerEmissions from three modern HD vehicles were investigated on a chassis dynamometer. One vehicle uses PM-Kat and meets EURO IV standards. The second one complies with EURO V standards and uses SCR. The third vehicle is a EURO IIII HDV which was tested with and without diesel particulate filter. The investigation focused on solid particles in the mobility size range of 10-400nm. The instruments used were SMPS, NanoMet, PASS and ELPI. For the majority of operating points for EURO IV with PM-Kat and EURO V with SCR, a moderate reduction in nanoparticle emissions was observed compared to EURO III without DPF. However, at full load the EURO V engine emitted higher particle concentrations than a EURO III engine without DPF. The gaseous emissions of the EURO V engine displayed low emissions. No deleterious effects were observed due to the SCR. The concentrations of NH3 and NO2 remained close to the detection limit. However, the EURO IV engine emitted rather high concentrations of NO2 at about half load range. It is estimated that well-known state-of-the-art methods for measurements, driving cycles etc. have been applied 2.2.3 Magdi KhairThe Magdi Khair study is part of the "Advanced Petroleum Based Fuels" project the purpose of which is to develop a 2010 Emission Control System (ECS) for heavy duty vehicles based on EGR, SCR and CDPF[3] technologies. The project measured particle and NO2 emissions using ESC and FTP driving cycles. Measurements were conducted before and after aging of the HDV engines. Emissions of NOx are lower by ESC driving cycles compared to FTP driving cycles. The opposite is the case for emissions of particles (by mass). NOx emissions after 200 hours are 0.27g/hp-hr (0.20 g/ kWh) for FTP whereas emissions are 0.19g/hp-hr (0.14 g/ kWh) applying the ESC driving cycle. After 6000 hours, the emissions by the FTP driving cycle is 0.24g/hp-hr (0.18 g/ kWh) while they are 0.21g/hp-hr (0.15 g/ kWh) applying the ESC driving cycle. 2.3 Findings and conclusionsThe available data do not allow for an exact calculation of number and size of particle emissions. Instead, the study compares the reduction in number of particles compared to EURO III technology. The three studies support the finding that EURO V with SCR/urea emission reduction system seems to reduce carbonaceous particles by up to 70% - and it will probably be the most common solution in the years to come. This is a considerable reduction, however, a significantly smaller reduction compared to technologies with particulate filters. Regarding NO2 emissions, the studies indicate that the SCR/urea technology is effective in terms of reducing NOx and NO2. On the other hand, EURO IV with PM cat emits substantially more NO2 compared to the EURO V with SCR emission reduction system. [3] If a catalytic converter is coated on the surface of the diesel particulate filter, the filter is calledCDPF
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