The Influence of Synthetic Oxygenates on Euro IV Diesel Passenger Car Exhaust Emissions - Part 3

The paper presents the test results relating to the influence of carbonate oxygenated additives to diesel fuel on exhaust emissions. Following the previous tests of glycol ethers (SAE Paper 2007-01-0069) and maleates (SAE Paper 2008-01-1813), the authors decided to use carbonates to obtain an even greater reduction in PM emissions.

The significant effectiveness of carbonates on PM emission reduction was confirmed in tests performed by the authors. Diethyl carbonate was the most effective oxygenated compound with regard to PM emission reduction among all the 11 oxygenates which have been tested so far. Moreover, it is important to note that diethyl carbonate caused only a small increase in NO_x emissions, thus it allowed for an essential improvement in the PM/NO_x trade-off. A significant increase in the CO and HC emissions was, however, a negative effect of the use of carbonates. Comparing the effects of the use of carbonates in the NEDC and FTP-75 cycle it was found that the changes in the emissions were much more advantageous during the European cycle.