Biofuel production of neem wood bark (Azadirachta indica) through flash pyrolysis in a fluidized bed reactor and its chromatographic characterization

Abstract

ABSTRACT In this study, wood bark of neem tree (Azadirachta indica) is transformed into liquid (bio-oil), solid (char) and gaseous products via pyrolysis method. The main aim of this study is to analyze the effect of process parameters on pyrolysis yield, physical and chemical characterization of bio-oil, char, and gaseous products to find its feasibility as a commercial fuel as well as chemical feedstocks. The flash pyrolysis experiments were carried out in a laboratory scale fluidized bed reactor at a temperature ranging from 350 to 550°C, different particle sizes from 0.71 to 1.25 mm with a sweep gas flow rate of 1.25 to 2.25 m3/hr. The highest liquid product yield was obtained as 49.5 wt% at the pyrolysis temperature of 450°C, 1.0 mm particle size and at the sweep gas flow rate 2.0 m3/hr. The obtained bio-oil, char, and gaseous products were examined with FT-IR, GC-MS and Elemental analysis methods. Based on the elemental analysis of the bio-oil, the calorific value was found as 22.7 MJ/kg. GC-MS analysis of the bio-oil indicates that it mostly consists of phenolic and oxygenated compounds with alkanes, alkenes, ketones, and carboxylic acids. The pyrolysis gas fraction contains hydrogen, methane, oxygen, carbon dioxide, and carbon monoxide. The obtained bio-oil and gas can be used as a bio-fuel and bio-oil can be used as a valuable chemical feedstock. The char obtained are carbon-rich and are nearly equal to the standard fuel properties.