Ozonation of Pyrolytic Aqueous Phase: Changes in the Content of Phenolic Compounds and Color

• Published in: Chemical engineering & technology 2016-10, Vol.39 (10), p.1828-1834
• Main Authors: Liaw, Shi-Shen, Justo, Oselys Rodriguez, Perez, Victor Haber, Zhou, Shuai, Garcia-Perez, Manuel
• Format: Article
• Language: English
• Subjects: Bio-oil; Biomass; Color; Oligomers; Oxidation; Ozonation; Phenol oxidation; Phenolic compounds; Phenols; Pyrolysis; Pyrolytic aqueous phase; Reduction; Vanillin
• ISSN: 0930-7516; 1521-4125
• DOI: 10.1002/ceat.201500420

Ozonation on the phenols present in pyrolytic aqueous phases attained from biomass thermochemical conversion was evaluated. During ozonation, the dark color of original samples was found to decrease as a function of ozonation time. The oxidation kinetics of phenols was quantified by a method based on the color changes of samples. The oxidation profiles showed different behaviors and in some cases the phenols presented a positive correlation with the relative R color parameter, except eugenol, syringol, and vanillin which were markedly different. Finally, the color changes observed seem to be associated with the changes in the overall content of phenols and with the change in the molecular weight of the heavy fractions that include lignin oligomers. The pyrolytic aqueous phase attained from biomass fast pyrolysis used as substrate to generate bioproducts by microorganisms contains phenol inhibitors which must be removed. Ozonation turned out to be an efficient method for their reduction during which the dark color of samples diminished as a function of ozonation time. Thus, color changes were associated with the reduction of phenols.