Abstract
This paper describes the combustion characteristics and fuel properties of gas oil blended with fatty acid 2-ethylhexyls derived from palm/coconut oil. In this study, lauric acid 2-ethylhexyl (2H-12) having the cetane number of 66.7 and the pour point of -32.5ºC, and palmitic acid 2-ethylhexyl (2H-16) having the cetane number of 73.1 and the pour point of -2.5ºC are blended into gas oil to improve ignition quality and/or cold flow property. Experimental results of engine bench tests show that by blending 2H-12 or 2H-16 into gas oil, the ignition delay is shortened and premixed-like combustion immediately after the auto-ignition is suppressed. As the result, the thermal efficiency together with nitrogen oxide emissions are improved. However, the short ignition delay obtained at the blend ratio of 20vol% leads to increase in smoke emission.
