The use of waste transformer oil as alternative fuel in a diesel power generator

Abstract

In this study, waste transformer oil (WTO) was investigated as a fuel candidatefor a diesel power generator set in terms of its fuel and combustioncharacteristics. Kinematic viscosity, which is the most restrictive property ofWTO (9.6 mm2/s at 40 oC), was measured on different blends with aconventional diesel fuel (in 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100% byvolume) in order to detect the suitable blending ratio to be used in enginewithout any modification, and to propose some blending strategies to optimizeengine performance and emissions. The blended fuels containing WTO up to50% with diesel by volume were found to have a viscosity which is withinstandard value specified for conventional diesel fuels, i.e., 2.0-4.5 mm2/s inEN590, and in case 60% WTO, it agrees with EN14214 (3.5-5.0 mm2/s)alternative diesel fuel standards. It is also found that a fuel blend containing20% WTO and 80% diesel have a kinematic viscosity and density which arevery close to conventional diesel’ values. Therefore, WTO was blended withdiesel at the rate of 20% by volume and then tested in a 4-stroke and 4-cylinderdiesel engine powered generator set under constant speed-variable loadconditions. Measured and calculated results were compared with the results ofconventional diesel tested under the same conditions. Experimental resultsshowed that specific fuel consumption, NOx and unburned HC emissionsreduced when using blended fuel instead of conventional diesel. Cylinder gaspressure was higher for blended fuels than that of conventional diesel while thestart of combustion was later in the case of blended fuels.