Biochemical to enable Biorefinery: A case study of polyphenols extraction from Bio-oil for Utilization as Biodiesel Antioxidants

Although bio-oil from biomass pyrolysis can be hydrotreated or cracked into transportation fuel, economic and energy challenges remain. One strategy is to cogeneration of oxygen-containing biochemical with high value in biorefinery. Here, we developed a simple separation method with combination of distillation and chemical extraction to produce a stream of phenolic compounds mixture, potential of which as sustainable biodiesel antioxidants was explored. The study revealed that higher distillation temperatures (>250 ℃) contributed to the enrichment of methoxyphenols, binary phenols and ternary phenols. The presence of electron-withdrawing groups at the ortho and para positions of phenolic hydroxyl groups was found to enhance antioxidant activity. An increase in the number of phenolic hydroxyl groups also significantly improved antioxidant performance. Certain extracts with maximum amount of pyrogallol and exhibited comparable antioxidation performance, as compared to commercial antioxidants. Acetic acid, cyclopentanone, furfural, and benzyl ether exhibited a certain negative effect on antioxidant activity. Based on these findings, a graded utilization strategy for pyrolysis bio-oil was developed, and the economic feasibility was comprehensively evaluated. The minimum sales price of the biodiesel antioxidant was calculated to be $1,072.98 per ton, which is significantly lower than the market price of commercial antioxidants, indicating the economic potential of this strategy.