Automotive Sulfate Emissions-A Baseline Study

Sulfate in diesel exhaust

“…Results of the diesel sulfate speciation experiments are presented in Table II. SO2 -1 SO42-conversions range between 1.2 and 1.6% for the three vehicles tested and are comparable to results reported by other workers (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). In all cases a All emission results normalized to 0.03 wt % S in fuel.…”

“…The approximate 2% S -*• SO42-conversion in diesels is higher than is observed in noncatalyst spark-ignition vehicles (14)(15)(16)(17)(18)(19) and less than in oxidation-catalyst-equipped sparkignition systems (3,4,6,9,13). Because of the amount of sulfur in diesel fuel, however, the SO42-emission rate from a diesel system is comparable to that from an oxidation-catalystequipped spark-ignition system.…”

“…Diesel fuel contains on the average 0.2 wt % sulfur (1), or almost an order of magnitude more than gasoline (2). About 2% of the fuel sulfur burned in diesel engines is emitted as sulfate (SO42-) (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14), more or less independently of engine type or operating mode. SO42-usually comprises several percent, by mass, of the total airborne exhaust particulate matter (3, 5,8,10-14) from a diesel system.…”

Particle and smoke emission from a light duty diesel engine

“…The observation regarding the absence of metals in the sample is in agreement with that found by Braddock and Gabele (7). The observed sulfate content is somewhat lower than those (2-3%) reported previously (5)(6)(7)(8)(9). However, in all previous investigations the sample was diluted and, hence cooled, before it was collected and analyzed.…”

“…In addition there is evidence that the overall result is affected by the humidity of the gas stream (6, 9).…”