Experimental Investigation on a Compression Ignition Engine with Blends of Plastic Oil and Diesel as Fuel

Waste plastic is a conventional source of energy. It can be transformed into oil by thermal degradation method such as pyrolysis. In this work, pyrolysis plastic oil (PPO) was prepared by microwave pyrolysis method using waste plastic. The plastic oil was analysed, tested and used as the properties of it were similar to that of diesel. The single cylinder direct injection diesel engine was fuelled with different blends at different loads from no load to full load condition. The performance, combustion characteristics and emissions were recorded and compared with that of diesel. Based on the results, it is found that the brake thermal efficiency for blends PPO20, PPO40, PPO60, PPO80 and PPO100 at 90% of full load condition were lower by 3.9, 6.8, 8.3, 9 and 9.7%, respectively, with respect to diesel when the engine was operated at a constant speed of 1500 rpm. Specific fuel consumption for blends PPO20, PPO40, PPO60, PPO80 and PPO100 at 90% of full load were higher by 0.4, 1.2, 2, 3.6 and 6%, respectively, as compared to diesel at constant speed (1500 rpm). The NO_x emissions for blends PPO20, PPO40, PPO60, PPO80 and PPO100 at 90% of full load were higher by 7.65, 13, 17, 23 and 24.2%, respectively, as compared to diesel while engine was running in constant speed (1500 rpm). The CO emissions for PPO blends PPO20, PPO40, PPO60, PPO80 and PPO100 at 90% of full load were lower by 6.5, 17.4, 26, 30.4 and 7.6%, respectively, as compared to diesel at constant speed (1500 rpm). The UHC emissions for PPO blends PPO20, PPO40, PPO60, PPO80 and PPO100 at 90% of full load were lower by 6.5, 17.4, 26, 30 and 39%, respectively, as compared to diesel at constant speed (1500 rpm). It can be concluded that the plastic oil could be used as a substitute fuel in diesel engine.