Feasibility assessment for replacing rapeseed oil by selected vegetable oils in diesel engine

Abstract

To study the feasibility of replacing rapeseed oil used as fuel of diesel engines by other vegetable oils, comparative studies were conducted of rapeseed oil combustion process with palm and sunflower oil. The tests have been carried out for the fuel injection pressure:70, 100 and 135 MPa, pressure in chamber equal to 0.5, 0.7 and 0.9 MPa and the excess air factor from 1.25 to 5 (1.25; 2.50; 3.75; 5.00). The progress of the combustion process was studies for four temperature levels: 350°C, 425°C, 500°C and 575°C. The following were considered as analysed parameters of the process: self-ignition delay, burning time and pressure growth. Based on the results of the conducted research, it is recommended to use palm oil to replace rapeseed oil as a fuel in a diesel engine. In addition, it is possible to use sunflower oil for this purpose. Characteristics of the rapeseed oil combustion process is most similar to process of palm oil. Moreover, the parameters of the palm oil combustion process are similar to those characterizing diesel (at temperature equalling to 575°C and pressure of 0.7 MPa and 0.9 MPa). Sunflower oil was characterized by lower maximum combustion pressure, longer autoignition delay (after 0.1s in every case) compared to other tested vegetable oils.