Renewable energy potential of bio-Oil from pyrolysis of gmelina arborea seeds cultivated in Nigeria

Abstract

The increasing demand for renewable energy sources has intensified the search for sustainable alternatives to fossil fuels. Gmelina arborea seeds, an underutilized biomass abundant in Nigeria, hold potential for bio-oil production. This study aims to explore the feasibility of utilizing Gmelina arborea seeds for energy generation through pyrolysis, contributing to cleaner energy production and environmental conservation. Seeds were collected from LAUTECH, Ogbomoso, and subjected to air and oven drying to reduce moisture content before being ground into powder. Pyrolysis was performed in a bench-scale screw reactor at temperatures ranging from 485 to 596 °C. The bio-oil produced was characterized using standard ASTM methods, including proximate and ultimate analyses, Fourier Transform Infrared Spectroscopy (FTIR), and Gas Chromatography-Mass Spectrometry (GC-MS), to determine its chemical composition and energy potential. The bio-oil yield ranged from 21.3 to 25.3 wt.%, with the highest yield of 25.3 wt.% achieved at 596 °C. Characterization revealed favorable energy properties, including a Higher Heating Value (HHV) of 40.13 MJ/kg, kinematic viscosity, density, and flash point within practical application ranges. FTIR analysis identified functional groups such as alkenes, carboxylic acids, alcohols, ethers, and ketones, while GC-MS detected hydrocarbons like alkanes, alkenes, phenols, and naphthalene. The low nitrogen content (2.58-2.80 wt.%) indicates minimal environmental impact. This study highlights the viability of Gmelina arborea seeds as a renewable bioenergy feedstock, offering a cleaner, sustainable alternative to conventional fuels.