Experimental Investigation of Fast Pyrolysis of Isoberlina doka-Derived Sawdust for Bio-Oil Production

Abstract

Fast pyrolysis is considered an emerging technology for biomass conversion into liquid oil. In this paper, the conversion of waste from Isoberlina doka tree processing into bio-oil using a bench-scale fixed bed reactor with a fluidized behavior within the bed zone has been investigated at temperatures of 400-500 °C and particle size ranges of <0.5 and 0.5-1 mm. Reactor with the total height of 140 mm consisting of three zones with gas inlet diameter of 10 mm, reaction zone diameter of 70 mm, outlet diameter of 15 mm and a coupled detachable inlet with a diameter 15 mm for biomass loading was used for experimentation. Nitrogen was used as the carrier gas, and the products were biochar, bio-oil and non-condensable gas. Thermogravimetric and derivative thermal analysis (TG/DTA) was carried out in order to understand the thermal behavior of wood particles. Bio-oil produced was analyzed using the gas chromatography mass spectrometry and the Fourier transform infra-red spectrophotometry methodologies. TG/DTA analysis revealed an initial 30.639% mass loss which correlates to hardwood thermal characteristics. Bio-oil yield from bench-scale pyrolysis increased with increasing temperature. A maximum bio-oil yield of 49.84 wt % was observed at the particle size range of 0.5-1 mm, bed temperature of 500 °C and time of 30 min. Volatile generation was at the peak of 54.54% (0.002655 kg/min). However, changes in the chemical composition and functional groups of bio-oil with temperature of production suited it for different usage purposes.