Effects of low concentration biodiesel blend application on modern passenger cars. Part 1: feedstock impact on regulated pollutants, fuel consumption and particle emissions.

Five biodiesels from different feedstocks (rapeseed, soy, sunflower, palm, and used fried oils) blended with diesel at 10% vol. ratio (B10), were tested on a Euro 3 common-rail passenger car. Limited effects (-2% to +4%) were observed on CO(2) emissions. CO and HC emissions increased between 10% and 25% on average, except at high speed - high power where emissions were too low to draw conclusions. NOx emissions increased by up to 20% for two out of the five blends, decreased by up to 15% for two other blends, and remained unchanged for one blend. Particulate matter (PM) was reduced for all blends by up to 25% and the reductions were positively correlated with the extent of biodiesel saturation. PM reductions are associated with consistent reductions in non-volatile particle number. A variable behaviour in particle number is observed when volatile particles are also accounted.

Effects of low concentration biodiesel blends application on modern passenger cars. Part 3: impact on PAH, nitro-PAH, and oxy-PAH emissions.

This study explores the impact of five different types of methyl esters on polycyclic aromatic hydrocarbon (PAH), nitrated-PAH and oxygenated PAH emissions. The measurements were conducted on a chassis dynamometer, according to the European regulation. Each of the five different biodiesels was blended with EN590 diesel at a proportion of 10-90% v/v (10% biodiesel concentration). The vehicle was a Euro 3 compliant common-rail diesel passenger car. Emission measurements were performed over the NEDC and compared with those of the real traffic-based Artemis driving cycles. The experimental results showed that the addition of biodiesel led to some important increases in low molecular-weight PAHs (phenanthrene and anthracene) and to both increases and reductions in large PAHs which are characterised by their carcinogenic and mutagenic properties. Nitro-PAHs were found to reduce with biodiesel whereas oxy-PAH emissions presented important increases with the biodiesel blends. The impact of biodiesel source material was particularly clear on the formation of PAH compounds. It was found that most PAH emissions decreased as the average load and speed of the driving cycle increased. Cold-start conditions negatively influenced the formation of most PAH compounds. A similar trend was observed with particulate alkane emissions.

Effects of low concentration biodiesel blends application on modern passenger cars. Part 2: impact on carbonyl compound emissions.

Today in most European member states diesel contains up to 5% vol biodiesel. Since blending is expected to increase to 10% vol, the question arises, how this higher mixing ratio will affect tailpipe emissions particularly those linked to adverse health effects. This paper focuses on the impact of biodiesel on carbonyl compound emissions, attempting also to identify possible relationship between biodiesel feedstock and emissions. The blends were produced from five different feedstocks, commonly used in Europe. Measurements were conducted on a Euro 3 common-rail passenger car over various driving cycles. Results indicate that generally the use of biodiesel at low concentrations has a minor effect on carbonyl compound emissions. However, certain biodiesels resulted in significant increases while others led to decreases. Biodiesels associated with increases were those derived from rapeseed oil (approx. 200%) and palm oil (approx. 180%), with the highest average increases observed at formaldehyde and acroleine/acetone.