Engine-out Benzene Emissions from Gasoline Vehicles and Effectiveness of Catalytic Converters

An experimental study was conducted on 2-stroke/4-stroke two-wheelers and a carburetted passenger car for engine-out benzene emissions from the in-use Indian vehicles, with and without a catalytic converter. The leaded gasoline, used for the study, was having 1.1 % vol. benzene and 16.6 % vol. total aromatics whereas unleaded gasoline was having 2.2 % vol. benzene and 35.2 % vol. total aromatics. Engine-out benzene was found to be linearly related to both, benzene and total aromatics content in the gasoline. Effectiveness of catalytic converter for conversion of the engine-out benzene was also studied. For two-wheelers, the concentration of engine-out benzene seems to be dependent upon the engine type i.e. 2/4-stroke engine and on conversion efficiency of the catalytic converters.