An experimental evaluation of novel biofuel and biodiesel from Ziziphus mauritiana seeds in DICI engine

The engine community is searching for novel fuels concerning sustained availability with superior properties to traditional engine fuels. From the seeds of Ziziphus mauritiana, vegetable oil is extracted and transesterified for improvement in its properties as engine fuel. The properties of the oil qualify it for engine applications. This investigation has been carried out on a 5.2 kW, 1500 r/min, eddy current loading compression ignition engine. Engine runs at different loads on neat Ziziphus mauritiana oil biofuel and on Ziziphus mauritiana biodiesel. Both fuels developed power at all loads of the engine. Ziziphus mauritiana oil has a lesser calorific value, elevated density, viscosity, and least brake thermal efficiency, highest emissions except for NOx. Ziziphus mauritiana oil properties were improved through transesterification. At maximum load, compared to Ziziphus mauritiana oil biofuel, Ziziphus mauritiana biodiesel has a percentage variation of 2.1%, 6.0%, 24.4%, 14.5%, and 31.4% increase in brake thermal efficiency, peak pressure, heat release rate, NOx, and carbon dioxide, respectively. A percentage variation of 40%, 26.1%, 33%, and 4% reduction in ignition delay, CO, HC, and smoke is observed, respectively for Ziziphus mauritiana biodiesel operation. Compared to Ziziphus mauritiana oil biofuel, the Ziziphus mauritiana biodiesel produced better results with lesser and nearly equal diesel emissions except NOx and smoke. Therefore, Ziziphus mauritiana biodiesel fuel can be used as a replacement fuel.