COMPARING EXHAUST EMISSIONS FROM HEAVY DUTY DIESEL ENGINES USING EN 590 VS. MK1 DIESEL FUEL

Projekt:

MK1 vs EN590

Sammanfattning:
This literature study is fully financed by the Swedish Transport Administration (STA) with the main objective to gather information whether there still is an emission gain to be found, on a national level, from the present Swedish diesel fuel quality, focusing on the use in heavy duty on-road applications and non-road mobile machinery (NRMM).

The literature study has been carried out by AVL MTC. A reference group consisting of members from the main stakeholders from the Swedish oil industry and heavyduty vehicle industry was formed by STA and have been contributing with material and expertise.

A large number of reports and other information material were potentially suitable for this study. More than half of the material initially collected did, however, not have enough data or the correct criteria to be included in this study. The most common imperfects was either the fuel quality (not Mk1 and EN 590 used in parallel) or engine technology (light duty diesel of pre Euro III heavy-duty engines). The material that past the criteria’s and has been used in this literature study can be found in the reference list in the end of this report.

Sweden has for quite some time been ahead of most other countries in Europe when it comes to automotive fuel qualities. This is particularly true for its diesel fuel quality. Since the beginning of the 1990: ies Environmental Class 1 diesel (Mk1), according to SS 15 54 35, has been the dominating diesel fuel quality in Sweden for the transport sector. This fuel was designed to reduce regulated and un-regulated emissions compared to the standard European diesel fuel of that time and further, to open up for the use of exhaust aftertreatment devices, as example, particle filters.

Over the years the European diesel fuel quality, specified according to EN 590, has improved and today the European and Swedish fuel qualities are much closer than what was the case 15 – 20 years ago. During the same period, emission legislations for heavy duty diesel engines have emerged from Pre-Euro up to Euro VI/EEV for on-road applications and from no legislation up to Stage IV for non-road applications.

The major questions to be answered with this literature study are; Is there still emission benefits when using Mk1 diesel fuel compared to current European diesel fuel qualities and how sensible (related to emissions) are newer technology heavy duty diesel engines for the remaining differences between Swedish Mk1 diesel and the European EN 590 diesel fuel qualities? The focus was to identify significant differences in tail pipe emission from heavy duty engines using Mk1 and EN 590 diesel fuels and also to identify any gaps in the current knowledge. A further objective was to make a quality assessment of available material.

Data from 4 engines meeting Euro III emission requirements, 5 engines meeting Euro IV emission requirements, 1 engine meeting Euro V emission requirements and 3 engines meeting Stage I emission requirements for NRMM has been used.

The conclusion is that data and experience from on-road Pre-Euro up to Euro III and non-road Stage I technologies are sufficient to conclude that Mk1 still has significant emission benefits in those applications.

The literature study has identified significant gaps in knowledge, especially for newer engine technologies. Even though engines meeting Euro IV emission requirements had the largest number of engines from the same emission category in this literature study, the knowledge bank is insufficient. Of the 5 Euro IV engines included in the study, 2 of them were prototype engines and most likely not representative for series production engines. On 1 of the others the exhaust emission aftertreatment system was modified. The 2 remaining engines are most probably not Volvo or Scania and therefore not representative for the Swedish vehicle fleet.

It is also quite clear that we are lacking information on the latest engine technologies, such as Euro V/EEV, Stage IIIA and Stage IIIB.

The study verified benefits on NOx, PM, PAH, PN and bio reactivity when using Mk1 diesel fuel. This has been the case in most investigations and in all the engine technology covered in this literature study.

When it comes to regulated emissions, engines of different engine technologies reacted in similar ways to Mk1 diesel fuel compared to EN 590. In other word, the relative emissions benefits found when comparing the two fuels used in engines meeting emission requirements according to Euro III, IV and V respectively was quite constant. This strengthens the apprehension that fuel formulation is of vital importance for the emission performance. But as the regulated emissions have been reduced with the newer engine technologies the differences in gram per kWh between the fuels have decreased.

Looking at the un-regulated emissions and bio reactivity the influence of the newer engine technologies was not as clear. It is unclear if newer engine technologies give a real emission benefit. What is important to high light is however that Mk1 still gave substantial emission benefits also on most un-regulated emissions and reduces the bio reactivity.

The recommendation regarding further investigations on emission benefits when using Mk1 specification diesel compared to EN 590 would be to focus on Euro IV, Euro V and Stage IIIA and IIIB engines. A special focus on un-regulated emissions, particle numbers and bio reactivity would be desirable. A further continuation of this project might be the case. Focus will then be on actual testing and analyses of the exhausts to fill the identified gap of knowledge.

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Författare: DANIEL DANIELSSON, LENNART ERLANDSSON
Utgivare: AVL MTC Motortestcenter AB
Utgivningsdatum: 2010-10-29
Antal sidor: 36
Språk: Engelska
Kontaktperson: Magnus Lindgren, PLkvm