Oxidation of organosolv lignin in a novel surfactant-free microemulsion reactor. (February 2021)

• Record Type: Journal Article
• Authors: Kong, Juanhua; Li, Lixia; Zeng, Qiang; Cai, Zhenping; Wang, Yingying; He, Hongyan; Liu, Sijie; Li, Xuehui
• Is Part Of: Bioresource technology. Volume 321(2021)
• Publication Date: 2021-02
• Subjects: Surfactant-free microemulsion -- Phase behavior -- Lignin oxidation -- Process intensification -- Metal sulfate; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2020.124466
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Surfactant-free microemulsion reactors were exploited to intensify lignin oxidation. About 40 to 500 wt% increment of phenolic monomers compared with single solvent. The solubilization and directionality of lignin at the surface favor its oxidation. H unit in lignin is depolymerized more easily than G and S units in this system. Abstract: Lignin is considered as a promising substitute for fossil resources, but its efficient conversion remains a huge challenge due to the structural complexity and immiscibility with typical solvents. Herein, a series of surfactant-free microemulsion reactors comprised of n -octane, water and n -propanol were designed and their corresponding phase behaviors alongside their ability to intensify oxidative depolymerization of lignin were explored. Experimental results show that the phenolic monomer yield improves substantially (40–500 wt%) by comparison with processes performed in a single solvent. Detailed characterizations also suggest that the above intensification is rationalized by the solubilization effect of microemulsion system and directional aggregation of lignin at the microemulsion interface.