Hifjur Raheman and Debasish Padhee Pages 79 - 85 ( 7 )
Background: The review of patents reveals that Handling of Jatropha seed cake after extraction of oil is essential as it contains toxic materials which create environmental pollution.
Methods: The goal of this work is complete utilisation of Jatropha seeds. For this purpose, Jatropha oil was used for producing biodiesel and the byproduct Jatropha seed cake was gasified to obtain producer gas. Both biodiesel and producer gas were used to generate electricity. To achieve this, a system comprising gasifier, briquetting machine, diesel engine and generator was developed.
Results: Biodiesel was produced successfully using the method patented for biodiesel production and briquettes of Jatropha seed cake were made using a vertical extruding machine. Producer gas was obtained by gasifying these briquettes in a downdraft gasifier. A diesel engine was then run in dual fuel mode with biodiesel and producer gas instead of only diesel. Electricity was generated by coupling it to a generator.
Conclusion: The cost of producing kilowatthour of electricity with biodiesel and diesel in dual fuel mode with producer gas was found to be 0.84 $ and 0.75 $, respectively as compared to 0.69 $ and 0.5 $ for the same fuels in single fuel mode resulting in up to 48 % saving of pilot fuel. Compared to singlefuel mode, there was 25-32 % reduction in system and brake thermal efficiency along with significantly lower NOx, higher CO and CO2 emissions when the bio-electricity generating system was operated in dual fuel mode. Overall, the developed system could produce electricity successfully by completely uti- lising Jatropha seeds without leaving any seed cake to cause environmental pollution.
Bio-electricity, emission, biodiesel, jatropha seed cake, producer gas, production cost.
Department of Agricultural & Food Engineering, Indian Institute of Technology, Kharagpur 721302 India.