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Butanol, a four-carbon alcohol, is considered in the last years as an interesting alternative fuel, both for Diesel and for gasoline application. Its advantages for engine operation are: good miscibility with gasoline and diesel fuels, higher calorific value than ethanol, lower hygroscopicity, lower corrosivity and possibility of replacing aviation fuels. Like ethanol, butanol can be produced as a biomass-based renewable fuel or from fossil sources. In the research project, DiBut (Diesel and butanol) addition of butanol to Diesel fuel was investigated from the points of view of engine combustion and of influences on exhaust aftertreatment systems and emissions. One investigated engine (E1) was with emission class “EU Stage 3A” for construction machines, another one, engine (E2) was HD Euro VI. The most important findings are: with higher butanol content, there is a lower heat value of the fuel and there is lower torque at full load.

An active oxidation catalyst is an efficient measure to reduce not only gaseous components (CO, HC), but also particle emissions (mostly oil condensates) of a small 2-stroke engine with lost oil lubrication. Since the 2- and 3-wheelers with 2-stroke propulsion are still a very serious source of air pollution worldwide in many urban areas, it is important to have a look on some consequences of an improperly working catalyst. The present paper shows some results of user-oriented aging of catalyst on the vehicle and results of limited emissions and unlimited (nano)particles during the catalysts screening tests. The works are a part of an international scooter network project, which was performed (2004 to 2007) in the Laboratories for IC-Engines & Exhaust Emission Control of the University of Applied Sciences, Biel, Switzerland with main support of the Swiss Federal Office of Environment (BAFU), Swiss Petrol Union (EV) and Swiss Lubes (VSS).

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.

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.

The Swiss 1998 Ordinance on Air Pollution Control (OAPC) mandates curtailment of carcinogenic Diesel particle emissions at construction sites [4]. In addition particle traps are compulsory at underground workplaces [3]. In compliance, more than 6,000 Diesel engines were retrofitted with different particle trap systems. Many traps surpassed 99% filtration efficiency, from the beginning, and secondary emissions were mostly prevented. However, trap failure due to mechanical and thermal damage was initially rather high at about 10%. By Y-2000 the failure rate was halved to about 6%. Thanks to focussed improvements, the Y-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%. Construction machines have much higher PM-emission factors than trucks, and are operated more intensely than tractors.