Biodiesel from Jatropha curcas oil using Zn for esterification step and solar radiation as energy source

Abstract

The production of biodiesel is greatly increasing due to its environmental benefits. However, production costs are still rather high compared to petroleum-based diesel fuel. In this investigation we report a production process that reduces the cost of biodiesel. The process proposed in this investigation, brings biodiesel production cost down due to the use of a solar heater as energy source to attain the reaction temperatures, the use of nonedible Jatropha curcas crude oil (JCCO) as raw material, and the use of low cost Zn filings as esterification catalyst.This biofuel was produced from nonedible Mexican J. curcas crude oil (JCCO) by a two step catalyzed process. The free fatty acids (FFAs) were first esterified with methanol, catalyzed by Zn filings. This catalyst showed a high FFA esterification activity and high stability. XRD study indicated that after 20 esterification runs, the Zn metallic surface remained unaffected. The use of Zn filings prevents the water waste streams, excess of methanol, high pressure and high cost stainless steel equipment used to eliminate the homogeneous acid catalyst that would have been used for the FFA esterification. During the second step, the triglycerides present in the JCCO were transesterified with methanol catalyzed by NaOH. The chromatographic analysis of the biodiesel obtained, revealed that the process proposed in this investigation led to a very high quality biodiesel, meeting the international requirements for its utilization as a fuel.