Combustion of waste trap grease oil in gas turbine generator

The possibility of using waste trap grease in electric power generation is explored in this study. The performance and emissions of both diesel and waste trap grease oils were tested in a gas turbine generator at comparable operating conditions. The fuel system of the gas turbine was modified for dual fuel capability with a diversion valve and a heat exchanger with exhaust for elevating the temperature of trap grease. The viscosity of trap grease was measured as a function of temperature and it was determined that the trap grease oil should be heated up to nearly 80 °C in order to approach the viscosity of diesel fuel such that satisfactory injector atomization can be achieved. The heating values of the diesel and trap grease were measured using an oxygen bomb calorimeter to facilitate the calculations of engine performance on an energy input basis. The results showed that the trap grease exhibits less NO_x emission for high generator loads compared to diesel, whereas CO and CO₂ emissions are slightly to significantly higher than those of diesel as load decreases. The results of the performance and emissions testing indicate that trap grease can be satisfactorily used for power generation.