Effects of Fuel Sulfur Content and Diesel Oxidation Catalyst on PM Emitted from Light-Duty Diesel Engine

Abstract

The effects of fuel sulfur content and diesel oxidation catalyst on number-size distribution, sulfate, and trace metals of particulate matter (PM) emitted from a Euro 3 light-duty diesel engine have been investigated. Three types of diesel fuel with sulfur content of 1000 ppm, 350 ppm and 19 ppm respectively were used in this study. According to the results, the number concentration of nanoparticles for low sulfur fuel compared to other two fuels decreased, but accumulation and coarse mode particles increased. With the use of DOC, the number concentration of different size range reduced at 50% load; while at full load, the reduction efficiency was 20-80% for 19 ppm sulfur fuel, and 30-50% only for nanoparticles for other two fuels. The results revealed that the presence of the catalyst and variations in fuel sulfur content altered the extent to which hydrocarbons and sulfates condense on the soot particles and the exhaust sampling methodology promoted the additional coagulation. Both sulfate emission rate and fuel consumption increased with sulfur content. Higher fuel consumption at higher load increased the concentration of SO 2 , and thus resulted in the generation of large concentration of sulfate. At low load, sulfate to PM mass ratio with DOC was less than that of without DOC; whereas at medium and high loads, the results were contrary. At medium and high loads, catalyst temperature was higher, which converted SO 2 into SO 3 effectively, and thus generated sulfate. The emission rates of Na, Ca, Mg, K, Al, Ni, and Cr for higher sulfur fuel were more than those for lower sulfur fuel. After engine was retrofitted with DOC, Na, K, and Fe emission increased regardless of load. The emission of Mg, Zn, Cu, and Ca were affected by DOC, as well as by load level.

Effect of biodiesel on particulate numbers and composition emitted from turbocharged diesel engine

“…About 15 mL of highly purified and deionized water was used to immerse the sampled material which was then sonicated for 20 min. A microcellular membrane filter was used to purify the extract (Zhao et al 2010). Above procedure was repeated once again to get another extract, and finally the two extracts were mixed together for the subsequent analysis.…”

“…The TME comes largely from the lube oil, fuel, detergents, and additives (Zhao et al 2010). A group comprising of crust elements like Ca, Fe, Mg, Al, and Si contributes about 82 % of the total metal content in diesel fuel (Wang et al 2003).…”

“…They are affected by various factors such as sampling methodology, engine type, fuel composition, lubricating oil, and driving cycle (Zhao et al 2010). The nuclei mode particles with diameter in the range of 5-50 nm contain a major portion of particles in number, while accumulation mode particles with diameter 50-1000 nm include most of the PM mass.…”

Characterization of Real-Time Particle Emissions from a Gasoline Direct Injection Vehicle Equipped with a Catalyzed Gasoline Particulate Filter During Filter Regeneration

“…The catalyzed filter has the potential to oxidize gas phase sulfur dioxide (SO 2 ; which is originated from the sulfur in the fuel) to form sulfur trioxide (SO 3 ). SO 3 can further combine with water vapor to form sulfuric acid vapor and nucleate downstream of the filter forming nanoparticles [26][27][28]. For catalyzed filters, certain catalysts may deliver active oxygen species to the soot and promote rapid soot oxidation.…”

Role of Biodiesel-Diesel Blends in Alteration of Particulate Matter Emanated by Diesel Engine

“…In general, PM is constituted by ashes or trace elements, volatile organic fraction or soluble organic fraction, sulphates and carbon soot, while the composition is affected by several parameters such as engine category, sampling technique, lubricating oil, composition of fuel and type of driving cycle (Zhao et al, 2010). Agarwal (2007) is of the view that PM consists of 40% unburned lubricating oil, 31% elemental carbon, 14% sulphates, 7% unburned fuel, and 8% metals along with some other substances.…”