Fuzzy linear optimization of jatropha biodiesel fuel cycle using a life cycle model

• Main Author: Ballacillo, Jo-Anne B.
• Format: text
• Language: English
• Published: Animo Repository 2008
• Subjects: Biodiesel fuels; Jatropha curcas; Linear programming; Chemical Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/3710; https://animorepository.dlsu.edu.ph/context/etd_masteral/article/10548/viewcontent/CDTG004432_P.pdf
• Institution: De La Salle University

With the current global concerns on diminishing fossil fuel reserves and environmental degradation, various studies have been conducted regarding clean fuel substitutes that can be produced from renewable sources. This paper studies the fuel cycle of biodiesel sourced from Jatropha curcas. This research aims to optimize the fuel cycle of jatropha methyl ester (JME) and it focuses on the energy balance, carbon dioxide flow, land and water availability concerns of the biodiesel system. For the analysis of the energy system, the method of oil extraction and the extent of residues utilization were used as parameter variations. A matrix-based life cycle model was utilized for the computational structure and symmetric fuzzy linear programming (SFLP) was employed for the optimization of the system. Analysis of the results shows that the use of Jatropha curcas as feedstock for biodiesel feedstock yields a significant decrease in the amount fossil fuel-based resource consumption and the net CO2 releases in its entire life cycle amounting to almost 100%. Due to the utilization of residues from oil extraction, the power and heat generation processes may be displaced, allowing considerable savings on natural gas and petroleum and results to an energy surplus, which can be exported from the biodiesel system. Moreover, land and water use are not sensitive to the degree of utilization of the residues but rather to the method of oil extraction used. The higher the yield of oil extraction, the less resource is needed for plant cultivation. Furthermore, the system configuration that gives the optimal mix of technologies corresponding to the best compromise of the different targets considered is one wherein the oil extraction method used is the mechanical method and the residues from the extraction process are fully utilized. Keywords: fuzzy linear programming, life cycle assessment, biodiesel.