Table 4-8: Tank Truck Load for Local Distribution
(106 Btu LHV)
Table 4-9: Tank Truck and Pipeline Distance for Fuel Distribution
M100 Natural gas
Transport to distribution
4.1.4 Marine Vessel Emissions
Crude oil and finished fuels are shipped in tanker ships. Tankers are powered by steam turbines as well as low speed diesels. The most prominent propulsion system for ocean going tankers is a two-stroke diesel (Burghardt).
Table 4-10 shows emissions from typical marine diesel propulsion engines. The NOx emissions are comparable to or slightly higher than those from uncontrolled truck engines. Fuel consumption in g/bhp-hr is quite high. One reason for the higher fuel consumption is the higher calorific value of the heavy fuel oil used in marine diesels combined with combustion advantages of low speed operation and higher compression ratios. Fuel consumption of marine diesels has dropped from 140 down to 120 g/bhp-hr over the past two decades (compared to 215 g/bhp-hr for a diesel engine on the EPA transient cycle). NOx levels depend on engine load over the ships operating profile. Emission factors that take into account a ship’s operating profile and are expressed in g/kg fuel shown in Table 4-11.