Optimization of Bio-oil Production and Advanced Characterization of Pyrolysis Products from Creosoted Wood

Railways’ ties are made from dense hardwoods and chemically treated with preservatives, mainly creosote, to increase their service life. However, after their service life, the valorization or the disposal of this contaminated wood is challenging. Rapid pyrolysis of this creosote-treated wood is among the solutions to manage this dangerous residue. Thus, the objective was to valorize the creosote-treated wood waste through rapid pyrolysis. Experiments included contaminated-biomass grounding, characterization, and pyrolysis (at three different temperatures: 400 ℃, 450 ℃, and 500 ℃). The properties of the obtained pyrolitic oils and their contaminants were characterized. Results showed that the maximum yield of 85% of the bio-oil is obtained at a temperature of 500 ℃. At this temperature, the bio-oil reached its maximum in terms of density (1.728 g/cm3), viscosity (8.09 cP), calorific value (125.6 MJ/kg), water content (47.73%), ash content (0.43%) and inorganic concentrations (2489.14 ppm). However, this oil has the highest concentration of contaminants at 293250 ppm. The tangled composition and the presence of oxygenated compounds (20–50%) limit its potential use. Catalytic hydrotreatment reduced the oxygenated compounds and improved the quality.