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 candidate for a diesel power generator set in terms of its fuel and combustion characteristics. Kinematic viscosity, which is the most restrictive property of WTO (9.6 mm2/s at 40 oC), was measured on different blends with a conventional diesel fuel (in 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100% by volume) in order to detect the suitable blending ratio to be used in engine without any modification, and to propose some blending strategies to optimize engine performance and emissions. The blended fuels containing WTO up to 50% with diesel by volume were found to have a viscosity which is within standard value specified for conventional diesel fuels, i.e., 2.0-4.5 mm2/s in EN590, 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 containing 20% WTO and 80% diesel have a kinematic viscosity and density which are very close to conventional diesel’ values. Therefore, WTO was blended with diesel at the rate of 20% by volume and then tested in a 4-stroke and 4-cylinder diesel engine powered generator set under constant speed-variable load conditions. Measured and calculated results were compared with the results of conventional diesel tested under the same conditions. Experimental results showed that specific fuel consumption, NOx and unburned HC emissions reduced when using blended fuel instead of conventional diesel. Cylinder gas pressure was higher for blended fuels than that of conventional diesel while the start of combustion was later in the case of blended fuels.