The effect of Jatropha seed cake producer gas flow rates on a diesel engine operated on dual fuel mode at high engine speed

Abstract

Jatropha seed cake is a byproduct of biodiesel production. The seed cake can be used to make a producer gas that can be fumigated into a diesel engine operated on dual fuel mode without major modification. This paper intends to investigate the impact of Jatropha seed cake-derived producer gas mass flow rate on the performance and emission characteristics of a diesel engine operated on a dual fuel mode at a high engine speed of 3,000 rpm. The results highlight that the maximum diesel replacement rate reached 60% at a 20 kg/h gas flow rate when the engine was operated at medium engine load. An increase in gas flow rate augments the diesel substitution rate but decreases the electrical-thermal efficiency (ETE). At 70% of the full engine load, the specific diesel consumption declined from 0.337 to 0.185 kg/kWh when the gas was increased from zero to 20 kg/h. At this engine load, the ETE sharply fell off from 25% to 10.6% and 6.6% when the gas flow rate increased from zero to 10 kg/h and 20 kg/h, respectively. The electrical specific fuel consumption and electrical specific energy consumption, exhaust hydrocarbon (HC), carbon monoxide (CO), and carbon dioxide (CO2) emissions were found to be higher with an increase in gas flow rate. Unlike dual fuel engine operation at medium speed, the nitrogen oxides (NOX) emissions were consistent with an increase in gas flow rate. Based on the empirical findings, the dual producer gas-diesel engine should be operated at high engine load but not at a high engine speed of 3,000 rpm with a maximum gas flow rate of 20 kg/h.