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Clean, very low sulfur fuels produced from domestic resources are of interest to the U.S. Military to enhance supply security and reliability versus continuing to rely on the supply of fuels that are either manufactured from an increasing percentage of imported oil or imported in increasing amounts as finished products. [1]* Synthetic Fischer-Tropsch (FT) fuel is one type of fuel that can be produced from domestic resources. FT fuels can be produced from a variety of non-petroleum feed stocks, such as natural gas, coal, petroleum coke, or even biomass and various wastes. Starting with reforming or gasification processes, the FT technology first produces synthesis gas (syngas) which is subsequently processed to high-boiling hydrocarbons. These hydrocarbons are then hydrocracked, hydroisomerized, and/or hydroprocessed to produce the desired liquid fuels. The military has a Single Battlefield Fuel Policy which mandates use of the JP-8/JP-5/Jet A-1 aviation turbine fuels.

As the U.S. Military considers fuel sources around the world and into the future, fuels produced via non-conventional means are anticipated to become increasingly available and of growing importance. One such type of fuel, a synthetic fuel, can be produced from conversion processes employing Fischer-Tropsch (F-T) synthesis and starting with natural gas, coal or biomass feed stocks. The Single Fuel Forward (SFF or single fuel in the battlefield) policy requires the use of JP-8, JP-5 or Jet A-1. Evaluations of F-T fuels, such as synthetic JP-8, in military ground vehicles, aircraft, associated equipment, and fuel storage and distribution systems is needed to assess ability to meet desired and/or required operational performance and to identify potential issues, as well as potential benefits, with the introduction and use of these fuels.

Sulfur and aromatic compounds in diesel fuel impact the emissions profile of current diesel engines. Fuels that do not contain these components can be made from natural gas using Fischer-Tropsch chemistry. Very little data has been presented comparing the emissions characteristics of current low sulfur diesel to fuels with ultra low levels of sulfur and aromatics in passenger car diesel engines. This study reports on an exhaust emission comparison of currently available conventional diesel fuel to Fischer Tropsch diesel fuel free of aromatics and sulfur comparisons included regulated emissions, air toxics, aldehydes and ketones, particle size distribution, and greenhouse gas emissions. Testing was conducted on a current model diesel passenger car using a chassis dynamometer. Regulated emissions were analyzed according to the Code of Federal Regulations (CFR) Title 40 specifications and requirements of the Environmental Protection Agency (EPA) Federal Test Procedure (FTP).

This study compared diesel exhaust emission from four different diesel fuels: a conventional low sulfur D2 diesel (0.03% sulfur, 28% aromatics), California Air Resources Board (CARB) diesel (0.015% sulfur, 8% aromatics), “Swedish” diesel (<0.001% sulfur, 4% aromatics), and a Fischer-Tropsch (F-T) diesel (<0.0001% sulfur, <0.1% aromatics) fuel. The comparison included regulated emissions, hydrocarbon speciation, air toxics, aldehydes and ketones, particle size distribution, and greenhouse gas emissions. Testing was conducted using a Cummins B-Series engine installed both in a heavy light-duty truck operating on a chassis dynamometer and on an engine dynamometer. The chassis driving cycles included city, highway, and aggressive driving operation. Engine dynamometer tests included the U.S. transient cycle.

The effect of viscosity index improver chemistry on the low temperature performance of engine oils in on-highway trucks must be understood in order to formulate oils for this application. Laboratory data, both from motored and fired heavy duty diesel engines, has been recently published, but no actual field performance in heavy duty diesel engines has been published. This paper reports on a testing program designed to compare the performance of three different VI improvers and two commercial oils under field and laboratory conditions. The test program was designed to determine if different VI improvers (1) affect engine oil pumpability as perceived by the operator, (2) satisfy the lubrication requirements of the engine, and (3) determine if different oil formulations perform the same in different engine designs. The testing program also addressed the correlation between laboratory and field testing of lubricant pumpability.