Exhaust Emissions from a City Bus Fuelled by Oxygenated Diesel Fuel

The benefits associated with the use of oxygen-containing diesel fuels in passenger cars are quite well described in the literature. This work describes the results of an 18-meter EEV city bus fueled with diesel fuel with the addition of 10% v/v of triethylene glycol dimethyl ether. This compound was chosen because it was effective in reducing exhaust emissions from light duty diesel vehicles. Emission tests (CO, HC, NO_x and PM) of the city bus were performed over SORT (Standardized On-Road Tests) cycles using portable exhaust gas analyzers - PEMS. Significant differences in the emission of exhaust components were observed in individual SORT cycles. The level of road emissions reduced as the traffic smoothness increased, i.e. from the SORT 1 to SORT 3 cycle. The largest reduction in bus emissions associated with the use of the oxygenated additive (triethylene glycol dimethyl ether) applies to carbon monoxide and ranges from 50% for the SORT 3 cycle up to 90% for the SORT 1. For the other exhaust components, the changes caused by the use of triethylene glycol dimethyl ether were much smaller.