Experimental study of feasibility of orange peel oil as a partial replacement for gasoline fuel in SI engine with and without MAO coated piston

The scope of this work investigates the feasibility of using orange peel oil (OPO)-gasoline blends in a spark-ignition engine for the first time. Initially, fuel characterization of OPO is performed, and the fuel properties are reported. Subsequently, engine experiments were performed in a spark-ignition engine at a constant speed with different engine loads. Coating studies were performed by coating the engine piston based on the micro-arc oxidation technique with a view of improving the engine performances and emissions. Then, the in-cylinder combustion images were visualized using AVL visioscope software to justify and explain the experimental engine findings. The experimental engine results reveal that OPO10 (10% OPO + 90% gasoline) showed slightly lesser brake thermal efficiency and nitrogen oxide and higher hydrocarbon and carbon monoxide emissions when compared to gasoline. With the increase in the fraction of OPO in the blend, the combustion is delayed, and the maximum net heat release is reduced due to unfavourable physical properties of OPO, such as increased boiling range and viscosity. With coating, the limitations with the physical properties of OPO are overcome as the prevention in heat losses favoured the combustion. The BTE of OP010 with coated piston is comparable to that of gasoline without coated piston, whereas HC and CO emissions were lowered by 3.1% and 3.6%, respectively. In-cylinder combustion images showed that the diffusion flames are predominant for higher blends of OPO. With coating, the premixed combustion is improved in that OP010 showed less diffusion fraction compared to gasoline. Overall, the fundamental flame investigation study justifies the experimental engine findings of the OPO fuelled SI engine.

Automated summary

This study investigates the feasibility of using orange peel oil-gasoline blends in a spark-ignition engine and includes fuel characterization, engine experiments, and coating studies. The results show that the physical properties of orange peel oil limit the combustion, but these limitations can be overcome by coating, improving the performance and emissions. These findings have important implications for using orange peel oil as a fuel in spark-ignition engines.