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A well balanced use of alternative fuels is an important objective for a sustainable development of individual transportation worldwide. Several countries have objectives to substitute a part of the energy of traffic by ethanol as the renewable energy source. Investigations of limited and unregulated emissions of two 2-S scooters with gasoline-ethanol blend fuels have been performed in the present work according to the measuring procedures, which were established in the previous research in the Swiss Scooter Network (since 2000). The investigated fuels contained ethanol (E), in the portion of 5, 10, 15 and 20% by volume. The investigated 2-S scooters represented a newer and an older 2-stroke technology with carburettor. The newer one was investigated with and without catalyst and the older one only in the original state without catalyst.

Four of these Particulate Reduction Systems (PMS) were tested on a passenger car and one of them on a HDV. Expectation of the research team was that they would reach at least a PM-reduction of 30% under all realistic operating conditions. The standard German filter test procedure for PMS was performed but moreover, the response to various operating conditions was tested including worst case situations. Besides the legislated CO, NOx and PM exhaust-gas emissions, also the particle count and NO2 were measured. The best filtration efficiency with one PMS was indeed 63%. However, under critical but realistic conditions filtration of 3 of 4 PMS was measured substantially lower than the expected 30 %, depending on operating conditions and prior history, and could even completely fail. Scatter between repeated cycles was very large and results were not reproducible. Even worse, with all 4 PMS deposited soot, stored in these systems during light load operation was intermittently blown-off.

New Diesel exhaust gas aftertreatment systems, with combined DPF*) and deNOx (mostly SCR) systems represent a very important step towards zero emission Diesel fleet. These combined systems are already offered today by several suppliers for retrofitting of HD vehicles. Reliable quality standards for those quite complex systems are urgently needed to enable decisions of several authorities. The present report informs about the international network project VERT *) dePN (de-activation, de-contamination, disposal of particles and NOx), which was started in Nov. 2006 with the objective to introduce the SCR-, or combined DPF+SCR-systems in the VERT verification procedure. Examples of results for some of the investigated systems are given. These investigations included parameters, which are important for the VERT quality testing: besides the regulated gaseous emissions several unregulated components such as NH3, NO2 and N2O were measured.

A modern HD-Diesel engine for construction machines, Liebherr D 934L (120kW) was set-up for a monofuel operation with crude, cold pressed rapeseed oil (ROR)*). The engine was equipped with a supplementary fuel filtration, supplementary engine & fuel heating for cold start and an appropriate fuel temperature control for the engine operation. A special lube oil was applied. After an extensive basic research of emissions including nanoparticles and energy consumption some adaptations of engine setting were performed: modification of the camshaft to eliminate the internal EGR (same valve timing and lift), earlier start of injection (SOI) at high- and full load, application of a combined exhaust gas aftertreatment system DPF+SCR, testing of DPF+SCR according to the VERT quality verification procedure.

Diesel particle filters (DPFs) efficiently eliminate soot, fuel-, and oil-ash emissions of diesel engines, but little data are available with respect to long term aging or deterioration effects of DPFs under real world operating conditions. Aging of wash coat- and catalyst-materials, catalyst poisoning, ash sintering, adsorption and long lasting storage of semi- or non-volatile substances can take place, which over time may influence filtration and conversion properties of DPFs. Herein we report to what extent DPF aging may affect particle filtration characteristics. We compared particle number concentrations (PN), and particle mass (PM) emissions after a 2000 operating hours endurance test (VFT2). Such a controlled field test is required by VERT verification procedures, which lately were published as a national standard (SNR 277205).

Due to the limited energy resources as well as due to increasing CO2-emissions the importance of alternative- and biogene fuels increases continuously. Investigations of the engine operation were performed on a latest technology Liebherr engine for construction machines, which was operated using crude rapseed oil (ROR), rapseed methyl ester (RME) and synthetic Gas-To-Liquid fuel (GTL) without any change of ECU setting. On this occasion the combustion diagnostics, behaviour of the injection system and the pollutant emissions, including the unlimited nano-particles were especially assessed. For injection (with this unit pumps system) it can be stated, that ROR and a little bit less RME shorten the injection lag and increase the maximum injection pressure. At higher engine load this causes the 50% heat release a little earlier (1-2°CA) and as consequence higher NOx and lower specific energy consumption.

Limited and nonlimited emissions of scooters were analysed during several annual research programs of the Swiss Agency of Environment Forests and Landscape (SAEFL, BUWAL)*). Small scooters, which are very much used in the congested centers of several cities are a remarkable source of air pollution. Therefore every effort to reduce the emissions is an important contribution to improve the air quality in urban centers. In the present work detailed investigations of particle emissions of a Peugeot scooter with TSDI (Two Stroke Direct Injection) were performed. The nanoparticulate emissions with different lube oils and fuels were measured by means of SMPS, (CPC) and NanoMet *). Also the particle mass emission (PM) was measured with the same method as for Diesel engines. It can be stated, that the oil and fuel quality have a considerable influence on the particle emissions, which are mainly oil condensates.

Due to increasing concern about health effects of fine and ultra-fine particles (nanoparticles) from combustion engines, the diesel particle filter technology (DPF) *) was extensively introduced to heavy duty and passenger cars in the last years. In this respect, a very important parameter is the irreversible plugging of the DPF with non-combustible ashes. The quality of lubrication oil, especially the ash content has a certain influence on regeneration intervals of diesel particle filters. In the present study, the effects of different lubrication oils on particle mass and nano-particle size distribution were investigated. The test engine was a modern diesel engine without particle filter system. A main goal was to find out, how different lubrication oils influence the particulate emissions and the contribution of oil to total particle emissions. Moreover, first results of a tracing study will be discussed.

Vegetable oils blended to Diesel fuel are becoming popular. Economic, ecological and even political reasons are cited to decrease dependence on mineral oil and improve CO2 balance. The chemical composition of these bio fuels is different from mineral fuel, having less carbon and much more oxygen. Hence, internal combustion of Diesel + RME (Rapeseed Methyl Ester) blends was tested with particular focus on nanoparticle emissions, particle filtration characteristics and PAH-emissions. Fuel economy and emissions of bus engines were investigated in traffic, on a test-rig during standardized cycles, and on the chassis dynamometer. Fuel compositions were varied from standard EN 590 Diesel with <50 ppm sulfur to RME blends of 15, 30, and 50%. Also 100 % RME was tested on the test-rig. Emissions were compared with and without CRT traps. The PAH profiles of PM were determined. Particles were counted and analyzed for size, surface, and composition, using SMPS, PAS, DC and Coulometry.

Most particulate traps efficiently retain soot of diesel engine exhaust but the potential hazard to form secondary emissions has to be controlled. The Diesel Particle Filter (DPF) regeneration is mainly supported by metal additives or metallic coatings. Certain noble or transition metals can support the formation of toxic secondary emissions such as Dioxins, Polycyclic Aromatic Hydrocarbons (PAH), Nitro-PAH or other volatile components. Furthermore, particulate trap associated with additive metals can penetrate through the filter system or coating metals can be released from coated systems. The VERT test procedure was especially developed to assess the potential risks of a formation of secondary pollutants in the trap. The present study gives an overview to the VERT test procedure. Aspects of suitability of different fuel additives and coating metals will be discussed and examples of trap and additive induced formation of toxic secondary emissions will be presented.

Based on the emission inventory Fig. 1, the Swiss 1998 Ordinance on Air Pollution Control (OAPC) mandates curtailment of carcinogenic diesel particle emissions at type B construction sites [1]. Moreover, particle traps are compulsory at underground workplaces [2]. In compliance, more than 6,000 Diesel engines were retrofitted with various particle trap systems. Many traps surpassed 99% filtration efficiency and secondary emissions were mostly prevented. However, trap failure due to mechanical and thermal damage was initially rather high at about 10%. By the year 2000 the failure rate was halved to about 6%. Thanks to focussed improvements, the year 2003 statistics show yearly failures of “only” about 2%. The Swiss target is to retrofit 15,000 construction machines with traps, fully compliant with environmental directives, having 5,000 operating hours durability and failure rates below 1%. Traps must pass the VERT suitability test before deployment.

1 Addition of gaseous fuels to the gasoline fuelled SI-engine offers several potentials of improvements, like: cold start without enrichment, lower engine-out emissions, in certain cases better strategy of catalyst heating. In the present work some results of investigations with addition of compressed natural gas CNG*) and of H2-containing reformer gases are presented. Two engines were fuelled with different compositions of H2-CO-CO2-N2 mixtures as model gases for methanol-, or gasoline- reformed fuels. The investigations were performed at warm, stationary, part load operation. Due to the presence of hydrogen the reformer gas causes more advantages, than CNG. It lowers the gaseous emission components, shortens the combustion duration, increases the combustion stability and enables much more expanded lean-limits and EGR-limits. The passive components of the reformer gas (CO2, N2) have similar influence on NOx-reduction as the internal EGR.

1 Analysis of limited and nonlimited emissions of scooters was performed during several research programs of the Swiss Federal Office of Environment Forests and Landscape (FOEFL) - and as a contribution to the European project ARTEMIS *). Small scooters, which are very much used in the congested centers of the European cities are a remarkable source of air pollution. Therefore every effort to reduce the emissions is an important contribution to improve the air quality in urban centers. In the present work detailed investigations of a Peugeot scooter with TSDI (Two Stroke Direct Injection) were performed and the emissions were compared to the other 2-S & 4-S scooters. As nonlimited emissions the nanoparticulate emissions at cold and warm operating conditions were measured by means of SMPS, ELPI and NanoMet *). The measurements were both: at steady state and at transient operating conditions.

1 During the research programs of the Swiss Federal Office of Environment Forests and Landscape (FOEFL) - and as a contribution to to the European project ARTEMIS*) analysis of limited and nonlimited emissions of motorcycles was performed. Exhaust emissions measurements of two motorcycles without catalyst: 4-stroke 750 cc and 1100 cc have been performed in the present work. Identical driving cycles have been repeated and the influence of the cooling duration on the emissions at cold start was investigated. A cold start in the temperature range of 20 ÷ 25 °C can be regarded as a “summer cold start”. As nonlimited emissions the nanoparticulate emissions at cold and warm operating conditions were measured by means of SMPS and NanoMe**). The measurements were performed at steady state and at transient operating conditions. The present work cleared up several details about the emissions of strong motorized motorcycles.

1 Analysis of limited and nonlimited emissions of scooters was performed during several research programs of the Swiss Federal Office of Environment Forests and Landscape (FOEFL) - and as a contribution to the European project ARTEMIS*). Small scooters, which are very much used in the congested centers of the European cities are a remarkable source of air pollution. Therefore every effort to reduce the emissions is an important contribution to improve the air quality in urban centers. In the present work detailed investiga-tions of a Peugeot scooter with TSDI (Two Stroke Direct Injection) were per-formed and the emissions were compa-red to the other 2-S & 4-S scooters. As nonlimited emissions the nanopar-ticulate emissions at cold and warm operating conditions were measured by means of SMPS, ELPI and NanoMet*). The measurements were both: at steady state and at transient operating conditions.

Fine pored hot gas traps have filtration efficiencies exceeding 99% of the solid particles in the diesel exhaust gas. There is a favorable trend to deploy this technology ex-factory and retrofitting on-road and off-road engines. The trap system however functions as a chemical reactor. The filter has a large effective area and the engine exhaust gas has plenty of reactants, which can promote undesirable chemical reactions that release toxic secondary emissions. These effects may be amplified when traps have catalytic influence, e.g. due to surface coatings or fuel-borne catalysts. The VERT suitability tests for particle trap systems therefore include a detailed test procedure for verifying the presence of over 200 toxic substances. These include PAH, nitro-PAH, chlorinated dioxins, furans as well as metals. The paper describes test procedures, test reporting, sample extraction and analysis.

Metallic substances, usually added to fuel as organic compounds are, as fuel additives proven to curtail particulate emissions from diesel engines and, as fuel borne catalysts (FBC), to promote regeneration of particle traps. During combustion, these substances form catalytic metal oxides and exit the combustion chamber as ultra-fine solid clusters in the mobility diameter range of 5-30 nm. Particles of this size and composition have a health impact and should not enter the respiratory air. FBC should therefore only be used together with particle traps, which can efficiently collect these metal oxide particles at all operating conditions. This and other requirements are stipulated in the VERT suitability tests for particle trap systems. The approval procedure includes a particle size-specific analysis to verify trap penetration in trace quantities.

Particulate traps are mechanical devices for trapping soot, ash and mineral particles, to curtail emissions from Diesel engines. The filtration effectiveness of traps can be defined, independent of the pertinent engine, as a function of the particle size, space velocity and operating temperature. This method of assessment lowers cost of certifying traps for large-scale retrofitting projects [1,2]. VERT [3] is a joint project of several European environmental and occupational health agencies. The project established a trap-verification protocol that adapts industrial filtration standards [4] to include the influence of soot burden and trap regeneration phenomena. Moreover, it verifies possible catalytic effects from coating substrates and deposited catalytic active material from engine wear or fuel/ lubricant additives.

1 Small scooters are very much used in the congested centers of the European cities. Even if there is a continuous technical progress, the small two-wheelers are a remarkable source of air pollution. During the research programs of the Swiss Federal Office of Environment Forests and Landscape (FOEFL) - and as a contribution to the European project ARTEMIS *) analysis of limited and nonlimited emissions of scooters was performed. Exhaust emissions measurements of two Scooters: 4-stroke 125 cc and 2-stroke 50 cc have been performed with and without catalyst. Identical driving cycles have been repeated and the influence of the cooling duration on limited the emissions at cold start was investigated. A cold start in the temperature range of 20 - 25 °C can be regarded as a “summer cold start”. As nonlimited emissions the nanoparticulate emissions at cold and warm operating conditions were measured by means of SMPS, ELPI and NanoMet *).