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The objective of this study was to quantify engine-out emissions of potentially toxic compounds from a modern diesel engine operated with different fuels including 15% v/v dimethoxy methane in a low sulfur diesel fuel. Five diesel fuels were examined: a low-sulfur, low-aromatic hydrocracked (∼1 ppm) fuel, the same low sulfur fuel containing 15% v/v dimethoxy methane, a Fischer-Tropsch fuel, a CARB fuel, and an EPA number 2 certification fuel. A DaimlerChrysler OM611 CIDI engine was controlled with a SwRI Rapid Prototyping Electronic Control system. The engine was operated over 4 speed-load modes. Each operating mode and fuel combination was run in triplicate. Thirty three potentially toxic compounds were measured for each fuel and mode.

The objective of this study was to quantify the effect of pilot fuel injection on engine-out emissions of potentially toxic compounds from a modern diesel engine operated with different fuels including 15% v/v dimethoxy methane in a low-sulfur diesel fuel. Five diesel fuels were examined: a low-sulfur (∼1 ppm), low aromatic, hydrocracked fuel, the same low-sulfur fuel containing 15% v/v dimethoxy methane, a Fischer-Tropsch fuel, a California reformulated fuel, and a EPA number 2 certification fuel. A DaimlerChrysler OM611 CIDI engine was controlled with a SwRI Rapid Prototyping Electronic Control system. The pilot fuel injection was either turned off or turned on with engine control by either Location of Peak Pressure (LPP) of combustion or the original equipment manufacturer (OEM) calibration strategy. These three control strategies were compared over 2 speed-load modes run in triplicate. Thirty-three potentially toxic compounds were measured.

The purpose of this paper is to make a preliminary assessment of the potential toxicity of compounds that might be emitted from diesel vehicles using urea/SCR technology. The use of urea as a reductant in the removal of NOx from the exhaust of diesel-powered vehicles has the potential to emit at least seven thermal decomposition products and unreacted urea from the tail-pipe. These compounds include: urea, ammonia, cyanate ion, biuret, cyanuric acid, ammelide, ammeline, and melamine. The toxicity data base for these compounds, in general, is poor. In addition, there have been few, if any, studies examining the inhalation route of exposure - the most likely route of exposure for people from vehicle exhaust. The measurement and identification of these compounds from the exhaust of urea/SCR- equipped vehicles is needed to prioritize the kinds of health effects studies required to understand the toxicity of these compounds.

An experimental study of the effects of partially-oxidized biodiesel fuel on the degradation of fresh fuel was performed. A blend of soybean oil fatty acid methyl esters (FAMEs) in petroleum diesel fuel (30% v:v biodiesel, B30) was aged under accelerated conditions (90°C with aeration). Aging conditions focused on three different degrees of initial oxidation: 1) reduced oxidation stability (Rancimat induction period, IP); 2) high peroxide values (PV); and 3) high total acid number (TAN). Aged B30 fuel was mixed with fresh B30 fuel at two concentrations (10% and 30% m:m) and degradation of the mixtures at the above aging conditions was monitored for IP, PV, TAN, and FAME composition. Greater content of aged fuel carryover (30% m:m) corresponded to stronger effects. Oxidation stability was most adversely affected by high peroxide concentration (Scenario 2), while peroxide content was most reduced for the high TAN scenario (Scenario 3).