Oxidative fast pyrolysis of banana leaves in fluidized bed reactor

Abstract

Dried banana leaves were previously chopped, characterized by proximate and elemental chemical analyses, thermogravimetric analysis (TGA), differential thermal analysis (DTA) and higher and lower heating value and submitted to oxidative fast pyrolysis in an auto-thermal fluidized bed reactor. The pyrolysis products were gases, bio-char and bio-oil (heavy and light phase). The gases were burnt in a combustion chamber and the energy was used for to heat the fluidization air in the reactor. The light bio-oil was analyzed by gas chromatography-mass spectrometry (GC/MS); the heavy bio-oil by infrared spectroscopy (FTIR/ATR) and higher and lower heating value; and the bio-char by elemental and proximate analysis, TGA, DTA and scanning electron microscopy (SEM). The mass yield and energy efficiency of the process were determined by mass and energy balances. The process produced 49.6% gases, 27.0% bio-oil and 23.3% bio-char. The light and heavy bio-oil presented complex chemical compounds and phenolic and acid nature. The heavy bio-oil showed elevated higher heating value of 25 MJ/kg. The bio-char released high energy under combustion, enabling it to be used as fuel. The results suggest potential for generating fuel products and chemical inputs from fast pyrolysis of dried banana leaves.