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A Euro 3 1.8-liter diesel vehicle with an oxidation catalyst was used to investigate real-world exhaust emissions over a real-world driving cycle that included urban congested traffic and extra-urban driving conditions. Diesel fuel and B100 were compared. The B100 fuel was Fatty Acid Methyl Ester (FAME), derived from waste cooking oil, which was mainly RME. A multifunctional additive package was added at 800 ppm to control fuel injector deposit formation. Gaseous emissions were monitored using an on-board heated Temet FTIR exhaust emission analyzer, which can measure 52 species at a rate of 0.5 Hz. A Horiba on board emissions measuring system was also used (OBS 1300), which measures the exhaust mass flow rate together with air/fuel ratio.

An on-board emission measurement system (PEMS), the Horiba OBS 1300, was installed in Euro 1-4 SI cars of the same model to investigate the impact of vehicle technology on exhaust emissions, under urban driving conditions with a fully warmed-up catalyst. A typical urban driving loop cycle was used with no traffic loading so that driver behavior without the influence of other traffic could be investigated. The results showed that under real world driving conditions the NOx emissions exceeded the legislated values and only at cruise was the NOx emissions below the legislated value. The higher NOx emissions during real-world driving have implications for higher urban Ozone formation. With the exception of the old EURO1 vehicle, HC and CO emissions were under control for all the vehicles, as these are dominated by cold start issues, which were not included in this investigation.

Small diesel engines are a common primer for micro and mini-grid systems, which can supply affordable electricity to rural and remote areas, especially in developing countries. These diesel generators have no exhaust after-treatment system thus exhaust emissions are high. This paper investigates the potential of introducing simulated synthetic gas (syngas) to diesel in a small diesel engine to explore the opportunities of widening fuel choices and reducing emissions using a 5.7kW single cylinder direct injection diesel generator engine. Three different simulated syngas blends (with varying hydrogen content) were prepared to represent the typical syngas compositions produced from downdraft gasification and were injected into the air inlet. In-cylinder pressure, ignition delay, premixed combustion, combustion stability, specific energy consumption (SEC), and gaseous and particle emissions were measured at various power settings and mixing ratios.

A cold start Euro 3 1.8 litre Diesel vehicle with an oxidation catalyst was used to investigate real world exhaust emissions over a driving cycle that included urban cold start congested traffic driving conditions. The aim was to identity those aspects of cold start real world driving responsible for higher emissions than in test cycles. Higher real world emissions may contribute to the problem of air quality in urban areas, which has not improved in quality in proportion to the reduced in vehicle exhaust emissions. Diesel, B50 and B100 fuel were compared to determine if real world driving effects were worse for B50 and B100 fuels due to their lower volatility and higher viscosity. The biofuel was WRME, derived from waste rape seed cooking oil. A multifunctional additive package was added to the biofuel at 800ppm to control fuel injector deposit formation. Gaseous emissions were monitored using an on-board heated Temet FTIR exhaust emission analyzer.

The influence of ambient temperature on exhaust emissions for an instrumented Euro 1 SI car was determined. A real world test cycle was used, based on an urban drive cycle that was similar to the ECE urban drive cycle. It was based on four laps of a street circuit and an emissions sample bag was taken for each lap. The bag for the first lap was for the cold start emissions. An in-vehicle direct exhaust dual bag sampling technique was used to simultaneously collect exhaust samples upstream and downstream of the three-way catalyst (TWC). The cold start tests were conducted over a year, with ambient temperatures ranging from - 2°C to 32°C. The exhaust system was instrumented with thermocouples so that the catalyst light off temperature could be determined. The results showed that CO emissions for the cold start were reduced by a factor of 8 downstream of catalyst when ambient temperature rose from -2°C to 32°C, the corresponding hydrocarbon emissions were reduced by a factor of 4.

The influence of ambient temperature on exhaust emissions for an instrumented Euro 1 SI car was determined for urban congested traffic conditions. In UK cities cold-starting vehicles directly into congested traffic conditions is a common occurrence that is not currently taken into account when modeling urban traffic pollution. In-vehicle emission samples were taken directly from the exhaust, upstream and downstream of the catalyst, using the bag sampling technique. The first bag was for the cold start emissions and approximately the first 1.1 km of travel. The following three bags were with a hotter catalyst. The cold start tests were conducted over a year, with ambient temperatures ranging from 2°C to 30°C. The results showed that CO emissions for the cold start were reduced by 70% downstream of the catalyst when the ambient temperature rose from 2°C to 30°C. The corresponding hydrocarbon emissions were reduced by 41% and NOx emissions were increased by 90%.

To maximize CO2 reduction, refined straight used cooking oils were used as a fuel in Heavy Goods Vehicles (HGVs) in this research. The fuel is called C2G Ultra Biofuel (C2G: Convert to Green Ltd) and is a fully renewable fuel made as a diesel replacement from processed used cooking oil, used directly in diesel engines specifically modified for this purpose. This is part of a large demonstration project involving ten 44-tonne trucks using C2G Ultra Biofuel as a fuel to partially replace standard diesel fuels. A dual fuel tank containing both diesel and C2G Ultra Biofuel and an on-board fuel blending system-Bioltec system was installed on each vehicle, which is able to heat the C2G Ultra Biofuel and automatically determine the required blending ratio of diesel and C2G Ultra Biofuel according to fuel temperature and engine load. The engine was started with diesel and then switched to C2G Ultra Biofuel under appropriate conditions.