Combustion performance and emission characteristics study of pine oil in a diesel engine

• The paper brings in to light a new type of biofuel, pine oil, for diesel engine.
• The Pine oil possesses low viscosity and the calorific value of it is comparable to diesel.
• The reported biofuel is used directly in diesel engine without trans-esterification.
• The brake thermal efficiency and maximum heat release rate increase by up to 5% and 27%.
• The HC, CO and smoke emissions are considerably reduced for pine oil at most of the loads.

A new type of biofuel, pine oil, is introduced in this work for the purpose of fueling diesel engine. The viscosity, boiling point and flash point of the reported oil are lower, when compared to that of diesel. Also, the calorific value of pine oil biofuel is comparable to diesel. As a result, it can be directly used in diesel engine without trans-esterifying it. Pine oil biofuel and their blends of 25%, 50%, and 75% with diesel were tested in a single cylinder, four-stroke, direct injection diesel engine and the combustion, emissions and performance results were compared with diesel. The results show that at full load condition, 100% pine oil reduces CO (carbon monoxide), HC (hydrocarbon) and smoke emissions by 65%, 30% and 70%, respectively. The brake thermal efficiency and maximum heat release rate increase by 5% and 27%, respectively. However, the NOx (oxides of nitrogen) emission is higher than that of diesel fuel at full load condition. The experimental work reveals that 100% pine oil can be directly used in diesel engine and potential benefits of pine oil biofuel have been reaped.