Ultra-clean Fischer-Tropsch (F-T) Fuels Production and Demonstration Project

摘要

The objective of the DOE-NETL Fischer-Tropsch (F-T) Production and Demonstration Program was to produce and evaluate F-T fuel derived from domestic natural gas. The project had two primary phases: (1) fuel production of ultra-clean diesel transportation fuels from domestic fossil resources; and (2) demonstration and performance testing of these fuels in engines. The project also included a well-to-wheels economic analysis and a feasibility study of small-footprint F-T plants (SFPs) for remote locations such as rural Alaska. During the fuel production phase, ICRC partnered and cost-shared with Syntroleum Corporation to complete the mechanical design, construction, and operation of a modular SFP that converts natural gas, via F-T and hydro-processing reactions, into hydrogensaturated diesel fuel. Construction of the Tulsa, Oklahoma plant started in August 2002 and culminated in the production of over 100,000 gallons of F-T diesel fuel (S-2) through 2004, specifically for this project. That fuel formed the basis of extensive demonstrations and evaluations that followed. The ultra-clean F-T fuels produced had virtually no sulfur (less than 1 ppm) and were of the highest quality in terms of ignition quality, saturation content, backend volatility, etc. Lubricity concerns were investigated to verify that commercially available lubricity additive treatment would be adequate to protect fuel injection system components. In the fuel demonstration and testing phase, two separate bus fleets were utilized. The Washington DC Metropolitan Area Transit Authority (WMATA) and Denali National Park bus fleets were used because they represented nearly opposite ends of several spectra, including: climate, topography, engine load factor, mean distance between stops, and composition of normally used conventional diesel fuel. Fuel evaluations in addition to bus fleet demonstrations included: bus fleet emission measurements; F-T fuel cold weather performance; controlled engine dynamometer lab evaluation; cold-start test-cell evaluations; overall feasibility, economics, and efficiency of SFP fuel production; and an economic analysis. Two unexpected issues that arose during the project were further studied and resolved: variations in NOx emissions were accounted for and fuel-injection nozzle fouling issues were traced to the non-combustible (ash) content of the engine oil, not the F-T fuel. The F-T fuel domestically produced and evaluated in this effort appears to be a good replacement candidate for petroleum-based transportation fuels. However, in order for domestic F-T fuels to become a viable cost-comparable alternative to petroleum fuels, the F-T fuels will need to be produced from abundant U.S. domestic resources such as coal and biomass, rather than stranded natural gas.