Particulate Emission Characteristics from a Middle-Duty Diesel Vehicle Fueled with GTL Gas Oil

Abstract

A middle-duty diesel truck was driven by 7 kinds of test gas oil which contained a GTL (gas to liquid) gas oil (middle distillate of Fischer-Tropsch synthesis oil) with the Japanese 10-15 mode and a truck mode determined by Kawasaki City, and its exhaust emission was measured.
Compared with emission characteristics by an ordinary commercial gas oil, the GTL gas oil caused negligible change in NOx emission, but showed 20% and more of the decrease in CO and HC emissions.
Concerning PM emission, a large decrease as large as 56% was attained for both test modes. The introduction of the GTL gas oil into local areas severely polluted by diesel-derived PM was expected to have a considerable effect. Moreover, the content of aromatic hydrocarbons in the test gas oil had a high correla-tion with PM emission, and it was found that a decrease in aromatic hydrocarbons in the gas oil was effective for decreasing PM emission.
For PAH's emission such as benzo (a) anthracene (B (a) A), 7, 12-dimethylbenzo (a) anthracene (DB (a) A), benzo (b) fluoanthene (B (b) F), benzo (k) fluoanthene (B (k) F), benzo (a) pyrene (B (a) P), indeno (1, 2, 3-cd) pyrene (IPyr) and benzo (ghi) perylene (B (ghi) P), 75% and more of the total amounts of the all PAH emission were reduced by using GTL gas oil for both test modes, compared with the commercial gas oil. Individually, B (a) A, DB (a) A, B (b) F and B (k) F showed especially a high positive correlation with the content of aromatic hydrocarbons in the test gas oil.