Chinese study looks at benefits of low sulfur

To study the effects of fuel sulfur content on the characteristics of diesel particle emitted from a typical engine used in China, two types of diesel fuel with a sulfur content of 30 parts per million (ppm) and 500 ppm were used in an engine dynamometer test. The two fuel types were tested under six operational conditions-1,400 revolutions per minute (rpm) at 20%, 50% and 80% load, as well as 2,300 rpm at 20%, 50% and 80% load. Gaseous pollutants and particulate matter (PM) emissions were sampled with AVL AMA4000 and Model 130 High-Flow Impactor (MSP Corp), respectively. The PM mass, total carbon (TC), organic carbon (OC), elemental carbon (EC) and water-soluble ion distribution were also measured. The results of the experiment showed that compared with high sulfur diesel, the application of low sulfur diesel can lower fuel-based PM emissions by 9.2-56.6%. Evidence was also found that OC oxidation was promoted by low sulfur diesel, but the effect on EC oxidation was dependent on engine speed. (March 1, 2009)