Vacuum pyrolysis of Tamanu seed (Calophyllum inophyllum): Fuel properties, distillation, and composition study of the pyrolytic oil

Abstract

BackgroundThe pyrolysis of Calophyllum inophyllum seeds holds significant potential for producing biofuels and value-added chemicals. Research aims to identify optimal process conditions for maximum yield of oil, and evaluate its properties and composition for fuel application. MethodsIn this study, vacuum pyrolysis of extractive-rich biomass such as Tamanu seed (Calophyllum inophyllum) was performed at 25 °C min−1. The composition, fuel properties, and distillation of oil confirmed its application as fuel which is compared with various non-edible seed pyrolytic oils. Significant FindingsThe resulting pyrolysis oil, constituting 69.53 % of the seed, boasted a calorific value of 42.78 MJ kg−1, 10 % water content, and a viscosity of 12.9 cSt. Its flashpoint and pour point were measured at 42 °C and 7 °C, respectively. Distillation exhibited a broad range of fractions, mimicking crude oil distillation, with 55 % comprising diesel-range fractions. GC–MS analysis identified 46 hydrocarbon compounds, indicative of fatty acid, cellulose, and hemicellulose degradation, producing alkanes, alkenes, esters, nitriles, acids, amides, and amines. Notably, the oil contained significant levels of oleic acid, palmitic acid, and stearic acid. The mechanism involved radical reactions, yielding diverse hydrocarbons and oxygenates, albeit with minimal aromatic formation. This elucidates the potential of Tamanu seed pyrolysis for sustainable biofuel production and value-added chemical synthesis.