Process parameter variation of Melia azedarach sawdust pyrolysis for fuel properties, physicochemical characterization, and in-depth speciation analysis

Abstract

Pyrolysis is a thermochemical process carried out at elevated temperature in absence of oxygen to decompose biomass into bio-oil, bio-char, and gases. The principal objective of this work was to study the effect of operating parameters (temperature, nitrogen flow rate, bed height, particle size, heating rate, and pyrolysis time) on Melia azedarach sawdust pyrolysis products and to carry out in line characterization of these products. Experiments were carried out in the temperature ranging from 450 to 600 ℃ with ramp rate of 50 ℃, 150 to 250 mL/min nitrogen flow rate, 2.1- to 8.4-cm bed height, 0.18- to 0.83-mm particle size, 10–30 ℃/min heating rate, and 40-–80-min pyrolysis time. Under optimal conditions of pyrolysis at 550 ℃, 150 mL/min nitrogen flow rate, 8.4-cm bed height, 0.18-–0.29-mm particles, 20 ℃/min heating rate, and 60-min pyrolysis time, highest bio-oil yield was obtained. Bio-oil was analyzed for density, viscosity, pH, higher heating value, carbon residue, Fourier transform infrared spectroscopy, gas chromatography–mass spectrometry, and 1H nuclear magnetic resonance. Bio-char was characterized via proximate, ultimate, higher heating value, energy yield, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, and Brunauer–Emmett–Teller surface area. Characterization of bio-oil confirmed its potential for generating biofuel-bioenergy and chemical feedstocks. High porosity and surface-area of biochar affirmed its usage as substrate for activated carbon and other applications. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.