Evaluation of Exxon Donor Solvent (EDS) coal-derived liquid as utility diesel fuel. Final report

The program consisted of three phases: (I) characterization of the physical and chemical properties of EDS, (II) evaluation of EDS in a laboratory medium-speed diesel engine, and (III) evaluation of EDS in a low-speed diesel engine operating at a utility. The characteristics of high aromatic content and low cetane number that were found during Phase I made it unlikely that EDS could be used as a direct substitute for diesel fuel without engine modification to provide ignition assistance. Phase II was conducted on a 12-cylinder General Electric Company 7FDL diesel engine. Blends of up to 30% EDS and 70% 0.2 diesel fuel (DF-2) were successfully consumed. Dual fuel tests were also conducted on a single cylinder by injecting EDS through the existing engine fuel oil system and injecting DF-2 through an auxiliary nozzle as an ignition source. Acceptable operation was achieved using 5 to 10% pilot oil heat input. Phase III was conducted on a 16-cylinder Cooper-Bessemer LSV-16-GDT diesel engine at an EUC plant in Easton, Maryland. Blends of up to 66.7% EDS and 33.3% DF-2 were successfully consumed. Dual fuel tests were also conducted on a single cylinder by injecting EDS through the existing fuel oil system and usingmore » a natural-gas-fueled precombustion chamber as an ignition source. Acceptable operation was achieved using 3 to 6% pilot gas heat input. The program confirmed that it is feasible to consume significant proportions of EDS in a diesel engine, but more development is needed before EDS can be considered a viable alternative liquid fuel for diesel engines, and an industrial hygiene program is needed to assure safe handling of the fuel.« less