Environment Friendly Biodiesel Synthesis and its Characterization Using Novel Non-Edible Oil Seeds

This study is confined to identify novel non-edible oil seeds as renewable feedstock for eco-friendly biodiesel synthesis. In this project nine novel non-edible oil seeds have been investigated systematically including collection, morphological identification and scanning electron microscopic studies, oil contents estimation, oil extraction, biodiesel synthesis, optimization, characterization and fuel properties analysis in comparison with international biodiesel standard that is GB/T (20828), American (ASTM D-6751, ASTM D-951) and European standards (EN-14214). The non-edible oil seeds used in this study includes Raphanus raphanistrum L., Prunus Cerasoides D. Don., Celastrus paniculatuswilld., Lepidium perfoliatum L., Corylus colurna L., Datura metel auctt. non L. sensu Clarke, Capparis spinose L., Pistacia chinensis ssp. Integerrima (J.L. Stewart) Rech., and Sinapis arvensis L. Nine different catalysts, categories into three groups i.e clay based catalyst (single metal base, clay metal hybrid composites, clay and metal oxide), metal complex and metal organic framework complex, were synthesized using in-situ wet impregnation method and reflux transesterification procedure was used for synthesis of biodiesel. Additionally, reusability study of synthesized catalysts was also done. All the oil seeds have low acid value (> 3% FFA) required for transesterification except Celastrus paniculatus seed oil (2.98 mg / KOH). Therefore, in case of Celastrus paniculatus acid esterification, involving use of sulphuric acid (1% H2SO4) as catalyst was employed to reduce its acid value prior to transesterification. In addition, optimization of different transesterification variables was carried out using Response Surface Methodology (RSM) built on Box-Benken Design. Results showed that maximum biodiesel yield (90.2%) was recorded for Capparis spinosa using Cu-Ni doped ZrO2 catalyst (1: 12 oil to methanol ratio, 2.5% catalyst amount, at 70 oC for 1.5 h) followed by Sinapis arvensis (90%) with Zr-MOF-67 (9: 1 oil to methanol ratio, 1.5% catalyst amount, at 70 oC for 2.5 h) and Celastrus paniculatus (89.42%) using trimetallic (Ce, Cu, La) loaded montmorillonite clay catalyst (1:12 oil to methanol ratio, 3.5% catalyst amount, at 120°C for 3 h). While, the lowest biodiesel yield was observed for Raphanus raphanistrum (83%) with Cu loaded montmorillonite clay catalyst (1:12 oil to methanol ratio, 4% catalyst amount, at 150°C for 5 h). These findings clearly depict that all the synthesized catalysts (Cu-Mmt, Cd-Mn-Mmt, Ce-Cu-La-Mmt, ZrOBT, Ni-BT, Mn-BT, Cu-Ni doped ZrO2, Co-Cr doped ZrO2 and Zr-MOF-67) were novel, active, and reusable during the process of transesterification for efficient conversion of seed oil to higher biodiesel yield. Based on these experimental findings the feedstock used in this project as raw material is novel, economically feasible and should be used for commercial production at mass scale. The study further recommends the mass cultivation of such feasible novel non- edible feedstock at global perspective to produce biodiesel at industrial level.