Search Results

The gaseous and particulate emissions from a light-duty diesel powered passenger car were measured by a variety of chemical analysis techniques for three different fuels, typical No. 1 and No. 2 commercial diesel fuels and the Federal Register No. 2-D smoke test fuel. Hydrocarbon emissions were found to be inversely related to fuel molecular weight. The NO2/NO ratio was found to be much higher than for gasoline engines approaching 0.3 at low load. Particulate emissions were approximately 0.3 grams/mile for all fuels and driving cycles tested. Sulfate emissions were high, approaching that of some catalyst cars. Sulfate emissions decreased with decreasing fuel sulfur and increased by a factor of two in highway driving over urban driving. The potential pollution problems with such cars are worthy of further study.

A review of the available data on sulfate emissions methods and emissions rates from both catalyst-equipped and noncatalyst cars has been made. Air-dilution methods of various sorts appear to give similar sulfates emissions results, comparable with those obtained by controlled condensation procedures. Mobile source SO2 measurements technology requires much more attention. At present, only the hydrogen peroxide oxidation to sulfate has been demonstrated to give reliable results. Summaries of several hundred catalyst and non-catalyst emission rates are treated to estimate California and 49-state emissions. A cruise-mode emission rate of about 0.03 g/mile appears appropriate for both monolithic and pelleted catalysts in 49-state cars.