Search Results

In the effort to design reliable diesel engines which meet the strict US Federal Regulations for emissions, considerable progress has been made by engine manufacturers. Particulate emissions are now below 0.25 g/BHPh and after 1994 will be below 0.1 g/BHPh. Diesel fuel has a revised specification limit of 0.05% sulfur as a means to assist diesel engine manufacturers in complying with the 1994 standard. Diesel oxidation catalysts (DOC) have been chosen as another means. A DOC can efficiently oxidize soluble organic particulate matter (SOF) and gaseous hydrocarbons while easily oxidizing SO2 to SO3-the latter being a particulate and undesirable. Selective DOCs have been developed which maintain the activity for SOF and minimize the undesirable SO2 oxidation step. However, performance for gaseous hydrocarbons may be negatively affected.

It is possible to have a clean green diesel engine with low exhaust emissions and excellent fuel economy. The two major requirements for this engine are a low sulfur diesel fuel to permit the application of emission controls, and the support of effective regulations and standards. The diesel engine is a major contributor to air pollution - especially within cities and along urban traffic routes. Because diesel engines are extremely durable - lasting for 20 to 40 years, once they are introduced in an area they contribute to the air pollution problems for decades. Off-road vehicles further contribute to the pollution problem. Consequently, India needs to devise an emission control strategy that addresses both new and old engines. In addition to the normal components of air pollution that cause ground level ozone and smog in the atmosphere, diesel exhaust also contains particulate and hydrocarbon toxic air contaminants (TAC). These pollutants pose additional human health concerns.