Feasibility study of jatropha shell gasification for captive power generation in biodiesel production process from whole dry fruits

• Use of Jatropha curcas shells in downdraft gasifier demonstrated.
• Compositional analysis, fuel analysis and ash fusion test performed.
• 64.8% and 24.5% thermal and electrical efficiencies obtained.
• 8 h of continuous operation sustained with intermittent charging.
• Captive power generation in integrated biodiesel production made feasible.

Jatropha curcas seeds are a promising feedstock for production of high performance biodiesel. The triglyceride-rich seeds are obtained upon de-shelling of dried fruit. In the present study, the empty shells, having calorific value of 17.2 MJ kg−1, were utilized as solid fuel in a 15 kg h−1 downdraft gasifier. Producer gas having calorific value of 5.2 MJ m−3 was obtained upon gasification, with an efficiency of 64.8% over 8 h of continuous operation. The gasifier was interfaced to a 100% producer gas engine, and continuous power generation (ca. 10 kWe) was demonstrated with overall efficiency of 24.5%. Captive power obtained in this manner would obviate the need for external sources of power for the operations of deshelling, screw pressing, oil refining, transesterification, glycerol purification and soap making in the integrated biodiesel production process, starting from whole dry fruits. The intermediate producer gas can additionally provide thermal energy for the process.