A comprehensive study on the effect of emulsification, solid nanoadditive and LPG dual fuel operation on engine behaviour of a WCO based compression ignition engine

Abstract

The influence of emulsification, solid nanoadditive and liquefied petroleum gas (LPG) dual fuel operation on engine's performance, emission and combustion behaviour of a waste cooking oil (WCO) of sunflower oil based compression ignition engine was studied experimentally. Initially test engine was operated in single fuel mode with neat diesel, and neat waste cooking oil (NWCO) as fuels at various loading conditions. In the second phase WCO was converted into its emulsion (WCO-EM) and tested in the engine. The WCO-EM was further modified into solid nanoadditive emulsion (WCO-NF-EM) and tested. Finally the engine was modified to operate in dual fuel mode, and tested with LPG as the inducted fuel with WCO-NF-EM as pilot fuel. The NWCO resulted in inferior engine operation with higher smoke, HC, and CO emissions as compared to neat diesel all power outputs. Significant improvement in brake thermal efficiency was noted with all the methods attempted. Dual fuel operation with WCO-NF-EM-LPG showed highest brake thermal efficiency which is very close to diesel value. Smoke and NO x emissions were considerably reduced with all the methods. Dual fuel mode with LPG induction showed the lowest smoke emission which was still lower than diesel value. The WCO-EM and WCO-NF-EM further reduced the HC and CO emissions at all power outputs. It is concluded that the WCO can be effectively used in Diesel engines by converting into its solid nanoadditive emulsion in the unmodified engine. Combining dual fuel operation with WCO-NF-EM-LPG could achieve the engine operation similar to diesel.