Physico-chemical analysis of pyrolyzed bio-oil from swietenia macrophylla (mahogany) wood

The Swietenia macrophylla wood used for the study was sun dried for about 48 h, pulverized using a hammer mill and then sieved to a particle size of about 425μm using Wiley milling machine. The prepared materials were pyrolyzed in a fixed-bed pyrolysis reactor in the temperature range from 425 to 500 °C. The product yields were collected at an interval of 25 °C. The maximum yield of bio-oil was recorded as 69.5wt.% at the pyrolysis temperature of 450 °C. The physicochemical properties and compositions of the feed materials and produced bio-oil were measured in order to quantify their potential for bio-energy use and industrial applications. The properties specifically measured include density, moisture content, ash content, pH, refractive index, cetane index, elemental composition, viscosity, and heating values. The ultimate analysis of the product showed that the contents of carbon, oxygen, hydrogen, nitrogen, and sulfur were 50.2%, 42.6%, 6.6%, <0.4% and <0.06% respectively. The viscosity, density, pH, moisture content, API gravity, ash content, HHV and LHV of bio-oil produced were found to be 4.6 mm²/s, 0.951 g/ml, 5.64, 21.4wt.%, 19.29, 0.15wt%, 29.52 MJ/kg and 28.08 MJ/kg respectively. These values were found to be in the ranges of values reported in the literature for bio-oils produced from biomass. The produced bio-oil had the much needed organic compounds typical of other woody biomass employed in commercial bio-oil manufacture. These compounds were classified into several groups; organic acids, ketones, phenols, alcohols, and aldehydes. The main components identified in the bio-oil are the aromatic and aliphatic compounds as well as carboxyl groups. The GCMS analysis of the product indicated the presence of 24 compounds which are useful as industrial chemicals and flammable gases: they include alkanes, alkenes, phenols, hydrogen, and levoglucosan. This study on bio-oil has demonstrated that mahogany wood is a useful biomass for the much sort potential fossil fuel substitute and finds vast application in the biofuel industry.