Yazhe Wang, Hanmin Yang, Zsuzsanna Czégény, Bence Babinszki, Gergő Szabó, Sophia Peters, Viktorija Tomkute, Tobias Brink, Weihong Yang
To reduce the environmental impact of the aluminium industry, this study evaluates various bio-oil fractions as precursors to synthesize bio-binder, which is a potential sustainable alternative to coal tar pitch. Bio-oil fractions, including unfiltered and filtered bio-oils, and their aqueous and organic fractions, were investigated. The bio-oil and bio-binder samples were extensively characterized in terms of physicochemical properties and toxicological assessment. The evaluation demonstrates that the organic bio-oil fraction exhibits higher carbon content, greater aromaticity degree, and improved thermal stability. Toxicity assessment reveals that filtration effectively reduces the toxic risk associated with the bio-oil. The bio-binder derived from the organic fraction possesses a higher carbon content of 74.5 wt.%, a viscosity of 4.84 Pa·s, and superior thermal and oxidative stabilities, compared to other bio-oil fractions. The green anode made of filtered organic fraction shows comparable apparent density and electrical resistivity to that made of commercial binder. The findings suggest that the filtered bio-oil organic fraction is a promising precursor for bio-binder synthesis, with properties approaching those of coal tar pitch. This study introduces comprehensive perspectives and methodologies for selecting and tuning bio-oil as a sustainable alternative for the carbon anode production in the aluminium industry.