Solvent and catalyst effect in the formic acid aided lignin-to-liquids. (December 2018)

• Record Type: Journal Article
• Authors: Oregui-Bengoechea, Mikel; Gandarias, Inaki; Arias, Pedro L.; Barth, Tanja
• Is Part Of: Bioresource technology. Volume 270(2018)
• Page Start: 529
• Page End: 536
• Publication Date: 2018-12
• Subjects: Lignin -- LtL -- Formic acid -- Ru/C -- Bio-oil -- Ethanol -- Water; 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.2018.09.062
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: The ruthenium catalyst increases the oil yield and improves the oil quality. Ruthenium is more active than nickel catalysts, especially at low temperatures. Ethanol is a better solvent system when higher oil yields are the priority. Ethanol is a better solvent for the stabilization of the bio-oil components. In water, highly oxygenated compounds, such as catechols, are obtained. Abstract: The effect of the type of solvent, ethanol or water, and a Ru/C catalyst were studied in the formic acid aided lignin conversion. The best results were obtained in the presence of the Ru/C catalyst and using ethanol as solvent at 300 °C and 10 h (i.e. 75.8 wt% of oil and 23.9 wt% of solids). In comparison to the water system, the ethanol system yields a significantly larger amount of oil and, at 300 °C and 10 h, a smaller amount of solids. The main reasons for this positive effect of the ethanol solvent are i) the formation of ethanol-derived esters, ii) C-alkylations of lignin fragments and iii) the generation of more stable lignin derivatives. The Ru/C exhibits significantly higher lignin conversion activity compared to other Ni-based catalysts, especially at 300 °C, which is related to the enhanced activity of the Ru 0 sites towards hydrogenolysis, hydrodeoxygenation and alkylation reactions.