Experimental Study on Bio-Oil Recovery from Biobased Building Insulation Materials and Its Upgrading

The International Maritime Organization released the regulations to reduce greenhouse gas emissions with environmentally friendly fuel with a maximum sulphur content of 0.5 wt%. Pyrolysis is one of the methodologies used to produce bio-oil with low-sulfur fuel production. However, pyrolysis bio-oil (PBO) has high acidity and corrosivity, poor volatility, high viscosity, and high oxygen content, making the energy density relatively low. This study aims to improve PBO quality produced from bio-based building insulation materials derived from hemp fibres for marine fuel. Non-catalytic supercritical ethanol was used with a ratio of ethanol to bio-oil of 1:1, 5:1, and 7:1 (v/v), and a fixed residence time of 30 minutes and a temperature of 260°C. The results show significant differences (P<0.05) that a ratio of 7:1 (v/v) was the optimum condition to reach a higher yield of upgraded bio-oil (UBO) by 85.47 wt% with a low gas yield produced by 3.14 wt%. The properties of UBO were significantly improved. The viscosity decreased from 741 to 20.10 mPa.s, the density decreased from 1,206 to 1,093 kg/m³, and the heating value increased from 20.94 to 27.11 MJ/kg. Moreover, UBO contains esters and ethers, proving that esterification and etherification were the main reactions taking place during supercritical ethanol treatment. However, these results still need to be developed to meet the international marine fuel standards.