Biodiesel production in a fixed bed reactor from Vernonia cinerea oil using calcined Pyrgostylus striatulus catalyst supported on activated carbon

Abstract

ABSTRACT The current study had focused on continuous production of biodiesel from Vernonia cinerea seeds using a fixed bed reactor loaded with green catalyst. The free fatty acid (FFA) of the underexploited Vernonia cinerea seeds is very high. Two-phase solvent extraction (TPSE) methodology was implied for the extraction of oil to reduce the FFA and eliminate two-step transesterification process. At the experimental conditions of 60:40 n-hexane-to-methanol ratio, 65ºC temperature, and 4 hours of extraction time, 40% of Vernonia cinerea oil was obtained with FFA of 1.8%. The FFA of the oil got reduced by 78.5% by the implication of TPSE method. The characterization of the bio-oil was performed using FT-IR and GC-MS analysis. Pyrgostylus striatulus shells were calcined and supported on activated carbon. This was utilized as the green catalyst for biodiesel production. A complete analysis of the shells before and after calcination and after loading on activated carbon was studied using Hammett indicator, XRD, SEM, EDX, and BET analyses. Fixed bed reactor loaded with the calcined catalyst was utilized for the conversion of Vernonia cinerea oil and methanol into biodiesel. A maximum conversion of 96% was observed at the process conditions of 65ºC, 25:1 methanol-to-oil-molar ratio, 350-mm catalyst bed height and residence time of 6 hours. FT-IR analysis and 1HNMR analysis were performed to check the conversion of oil to biodiesel. The physio-chemical properties of methyl esters from Vernonia cinerea oil were analyzed. Findings of this research support that the produced biodiesel meets the ASTM standards indicating the fuel to be commercialized.