Diesel Emissions Regulation and Control Impact of ARB Regulation

Diesel Particulate Matter Composition  Highly variable chemical mixture  Dependent on engine, fuel and combustion parameters  Balance of organic and inorganic carbon to sulfates is a function of sulfur fraction in fuel  Measured as all PM emitted from diesel engine  Difficult to measures in ambient air -- surrogates typically used -Elemental carbon -Organic carbon -Black carbon

California Inventory of Diesel Emissions (2000)

Sources of Diesel Emissions  On road mobile sources -Cars -Trucks  Off-road mobile sources -Heavy equipment -Trains -Marine Vessels  Stationary sources -Emergency generators -Other diesel-fueled equipment

ARB Diesel Risk Reduction Program  On-road mobile sources -Lower emissions standards for HDV engines -Retrofit existing engines -Solid waste vehicle standards -Other vehicle fleet standards  Off-road mobile sources -Lower emissions standards -Retrofit of existing engines -Auxiliary engine fuel standards -Harbor craft standards -Other marine vessel measures in progress

Required PM Emissions Reductions for Off-road Engines

On-Road PM Reduction Measures

Typical Diesel PM Reduction Measures  Lower Sulfur in fuel -Mostly reduces sulfate portion of PM  Add-on PM filter  Replace diesel fuel -With natural gas for some vehicles -With electrical power for other uses  Improve engine design to reduce PM emissions -Require newer models for use