Evaluation of EDS coal liquid as an alternative fuel for medium-speed diesel engines

A three phase study was initiated to evaluate the use of Exxon Donor Solvent (EDS) middle distillate coal liquid as an alternative fuel for medium-speed diesel engines in electric power generation facilities. The first two phases of that study, the characterization and laboratory engine testing of EDS, are the subject of this paper. The chemical composition and characteristics of neat EDS, as well as EDS/DF-2 blends, were determined. The blends, in varying proportions, were performance tested in a GE 12-7FDL engine. A pilot diesel fuel injection system was added to one cylinder of this engine and dual-fuel EDS operation was evaluated. The results demonstrated the feasibility of consuming EDS in this class of diesel engines, but indicated the need for extensive development work before the fuel can be used as common practice. The laboratory investigation provided the ground work for a field trial, the third step of the program.