Effect of tyre derived oil-diesel blend on the combustion and emissions characteristics in a compression ignition engine with internal jet piston geometry

Abstract

In recent years there have been significant developments seen in utilization of different derivatives obtained from pyrolysis of waste automobile tyres, as alternative fuels for CI engines. In an investigation, a blend comprising 40% light fraction pyrolysis oil obtained from a tyre recycling plant, 50% diesel and 10% an oxygenate additive Dimethyl carbonate (40LFPO+10DMC) was examined as an alternative fuel in a single cylinder, direct injection (DI) compression ignition (CI) engine. Even with the oxygenate additive, the 40LFPO blend exhibited inferior performance and higher smoke emission than those of diesel operation at full load in the same engine. Turbulence inducement is one of the methods to improve the combustion behavior of a CI engine. Therefore, in this investigation, an attempt was made to create more turbulence in the combustion chamber by providing internal jets in the piston, when the engine was run with the 40LFPO10DMC. The investigation results in terms of combustion, performance and emissions were compared with those of the engine run with the conventional diesel fuel with and without turbulence inducement, and presented in this paper. The hydrocarbon (HC), carbon monoxide (CO) and smoke emissions were found to be reduced by about 32.9%, 66% and 13% respectively, than the conventional piston at full load, while they were found to be lower by about 66.6%, 2.4% and 21.2% respectively, than those of diesel fueled engine with the internal jet piston at full load. The brake thermal efficiency of the 40LFPO10DMC blend was found to be improved with internal jet piston compared to that of diesel and 40LFPO. It was higher about 4.5% and 5.3% than those of diesel and 40LFPO blend respectively at full load.