Impact of biofuels on air pollutant emissions from road vehicles – Phase 2

Biofuels are a key element of the policy drive to improve transport sustainability and reduce this sector’s CO2 emissions. In the Netherlands an average of 4% biofuels are currently blended into petrol and diesel, a percentage set to rise in the coming years.

As part of the country’s Policy-oriented Research Programme on Atmosphere and Climate (BOLK) initiated by the (former) Environment ministry VROM, TNO and CE Delft investigated the extent to which this programme will affect the air-pollutant emissions of Dutch road traffic in 2020. To that end scenarios were first elaborated for the biofuel mix in that year, thereby varying the constituent shares of the various types of biofuels and including a range of potential blends. An extensive literature study was then carried out on the impact of the respective blends on the NOx and PM10 emissions of the various vehicle categories. The results to emerge were then used to estimate the impacts under the respective scenarios for 2020.

This study indicates that the impact on national NOx and PM10 emissions will be minimal, reducing them by 0-2% and 0.1-0.5%, respectively. An issue that still needs to be addressed, however, concerns the higher biodiesel blends (B30, B100), as the impacts of these on Euro V and VI vehicles, in particular, are still unclear. From the perspective of air quality, biofuels that ‘count double’ are to be recommended because these reduce the need for high-percentage blends.