Pyrolysis characteristics, fuel properties, and compositional study of Madhuca longifolia seeds over metal oxide catalysts

The present study was focused on the bioenergy potential of Madhuca longifolia (mahua, MH) seeds to produce renewable fuel via thermocatalytic conversion. The physicochemical characterization of MH seed confirmed its bioenergy potential. Three model-free models were used to predict the pyrolysis kinetics of MH. The thermodynamic and kinetic analysis showed that MH has complex reaction kinetics which depends on the reaction rate as well as reaction order. Mahua seed was pyrolyzed in a semi-batch cylindrical shaped reactor with (CuO, Al₂O₃, and NaOH) and without catalysts. The yield of pyrolytic liquid during thermal pyrolysis was 51.2 wt%, whereas the use of catalysts decreased the liquid yield slightly at various biomass to catalyst ratios. Further, characterization results revealed that the use of catalysts improved the properties of pyrolytic oil by reducing viscosity, oxygenated compounds and with increasing heating value and acidity. FTIR spectra of pyrolytic oil confirmed the existence of phenols, aromatics, water, and acids which was also supported by the ¹H NMR analysis. Further, GC-MS analysis confirmed reduction in oxygenated compounds and increase in alcohol.