Development of a Suitable Test Protocol Long Term Effect of Metallic Additives on the Efficiency of Pollution Abatement Technologies: Development of a Suitable Test Protocol Emissions and Health Unit Institute of Environment and Sustainability EC-JRC Ispra

Directive 2003/17/EC states: “… review process … has to consider the effective functioning of new pollution abatement technologies and the impact of metallic additives … on their performance …” Approach chosen by the Commission: development of a shared test protocol (having the objective of measuring the effects of metallic fuel additives on regulated exhaust emissions)

Three key issues to be addressed by the test protocol: Starting point: MVEG created a working group to establish a testing protocol “to define a sound and repeatable way of measuring the effect of fuel additives in fully formulated fuels on regulated exhaust emissions in the European market”[1]. (January 1999) Three key issues to be addressed by the test protocol: (1) Instantaneous effects (2) Sustained benefits over longer term vehicle operation (3) Long term no-harm to vehicle emission control systems [1] “Protocol for evaluation of fuel additive effects on emissions”, Special Fuels/Vehicle/Engines Performance Technical Experts Group, October 2002

Much progress was made, full agreement on all aspects of the protocol was not achieved. No consensus on long-term no-harm test: combination of a high temperature test (ZDAKW test cycle) and a low temperature test (AMA mileage accumulation test).

For the review process the stakeholder met again Meetings in May & November 2004, September 2005. No significant progress was made on the test protocol to evaluate the long-terms effects of metallic additives on emission control technologies and it was not possible to solve the related dispute. Bilateral contacts between stakeholder and JRC to examine in depth some aspects and to explore what alternative approaches could be followed.

Result: JRC believes that there is no way to achieve full agreement on the basis of the disputed section of the current version of the test protocol. Disagreement concerns fundamental aspects and it is not likely that this can be overcome through minor modifications to the current version of the test procedure. Crucial points that prevent from reaching the consensus: The parties have a very different view on the capability of an accelerated engine test to reproduce correctly the interactions between a fuel additive and the vehicle’s emission control system.

In particular: ZDAKW is rapid test of catalyst efficiency and durability. Not evident that it suits for investigating fuel/catalyst interactions. No proof that ZDAKW reproduces interaction mechanisms occurring in the majority of the real-world engine operating conditions. The catalyst is only one emission control system that could be affected by metallic additives. Engine/catalyst interaction depend also on design related aspects, they cannot be accounted for by fitting catalysts to a different engines ZDAKW has been designed to test one specific technology (the three way catalyst) and should be adapted for other technologies. In any case, ZDAKW should be complemented by a second test based on vehicle mileage accumulation to reproduce the mechanism occurring at low temperature.

Two options to get out of the stalemate (1) Validate the ZDAKW test by means of an extensive experimental programme Demonstrate that the combination of the ZDAKW test cycle and the AMA mileage accumulation test is fully equivalent to a mileage accumulation performed on road (alternatively on a track or on a chassis dyno) following a driving cycle covering the vast majority (minimum 90%) of the real-world driving conditions. (2) Develop a new test method based on fleet test and on a driving cycle covering the vast majority (minimum 90%) of the real-world driving conditions.

Both options require huge investments human resources time money No guarantee that first option can get to a positive conclusion More likely that a fully agreed test protocol can be achieved choosing the second option. November 2004: stakeholders in principle agreed that a well designed fleet test could be suitable for the purpose of the additive test protocol drawbacks: higher costs, longer testing time, higher variability of the results, etc..

framework for the development of September 2005, presentation of a Draft proposal for a framework for the development of a new test procedure for fuel additives to demonstrate no-harm to the vehicle’s emissions control system Introduction Although the use of engine based tests is widely accepted and it is demonstrated that they can satisfactorily predict the real behaviour of engine components, after-treatment devices, fuels, lubricants, for the specific purpose of evaluating the impact of metallic additives on vehicle’s emissions control system and in particular of demonstrating no-harm to it, a whole vehicle based test procedure is believed to be more appropriate for a number of reasons. Whole vehicle aging conducted using an appropriate driving cycle is closer to the “real-world” than engine aging. In fact, the factors that play a role in the deterioration of pollution abatement technologies (thermal aging, poisoning, coating with fuel impurities, physical deterioration, influence of weather conditions, etc.) are in general more correctly accounted for in a test procedure based on whole vehicle aging. This is especially true in case of additive effect evaluation, as full mileage accumulation means a much larger exposure of the emission critical components to the additive. Another advantage of the whole vehicle aging is that all the emission critical components (sensor, catalyst, engine, etc.) are tested under the same conditions. Furthermore, there is no need to adapt the test cycle to different after-treatment/engine technologies and it can cover adequately both the gasoline LD vehicles and the diesel ones. However, whole vehicle aging has also many drawbacks, like higher cost, longer execution time, lower repeatability and reproducibility, higher variability of the results. For this reason, a reduced/accelerated test to be used for screening purposes should be retained as an option.

New test procedure should be complementary to “Protocol for Evaluation of Fuel Additive Effects on Emissions” drafted by the MVEG Technical Experts Group. replace/complement chapter 9 of latest (October 2002) MVEG protocol version. be developed by an appropriate experts working group. Scope of new test procedure same as described in the chapter 2 of the latest version of the MVEG protocol

The test procedure for the evaluation of instantaneous additive effect on emissions has been accepted by all the parties The new test procedure deals only with the long-term effect of the additive on emissions. The test procedure will be based on whole vehicle testing and whole vehicle aging. In a second phase a whole vehicle accelerated aging test or a bench accelerated aging test could be introduced for screening purposes. Mileage accumulation will be performed on an adequate number of vehicles (test fleet). All the other provisions laid down in the scope of the test protocol (Chapter 21) are still valid.

The following parameters should be defined by the new test procedure: The objective of the proposed test procedure is to effectively predict in-use emission deterioration rates and emission levels by covering the significant majority of the distribution of emission deterioration of candidate in-use vehicles. The test cycle cannot simply match the speed and acceleration distribution of typical or average driving patterns as it would lead to only a 50% coverage. To achieve the above mentioned objective, a new test cycle covering at least 90% of the in-use emission deterioration must be developed. The following parameters should be defined by the new test procedure: Number of vehicles and range of technologies to be considered Mileage accumulation fuel and emission test fuel Lubricant oil to be used Management of accidents and break-downs involving test vehicles Frequency of emission tests and number of repetitions Evaluation criteria of the result Extrapolation of the results of the test fleet to the real fleet in order to evaluate the real impact on exhaust emissions

September 2005 result: No general agreement to develop a new full vehicle test cycle will be reached without having fully explored the potential of the ZDAKW Proposed next steps: (1) Collect relevant information to evaluate “real-world character” of ZDAKW (2) Prepare for data collection to develop a new full vehicle cycle in case step (1) fails

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l = 1,0 5700 1/min, 260 - 325 Nm 900 - 940 °C in front of catalyst, 10 x ( 3 x 10 min ) = 5 hours 5700 1/min, 260 - 325 Nm 900 - 940 °C in front of catalyst, SV = 85.000 1/h l = 1,0 5 x deceleration fuel cut-off 61 x 625 s = 10,6 hours 6 x 15,6 = 93,5 hours (total) 300 s 60 s 5 s 3500 1/min, 120 Nm 630 °C, SV = 22.000 1/h 2500 1/min, 100 Nm 540 °C, SV = 15.000 1/h 4500 1/min, 150 Nm 720 °C, SV = 35.000 1/h