title: Effective depolymerization of concentrated acid hydrolysis lignin using a carbon-supported ruthenium catalyst in ethanol/formic acid media.
abstract: Lignin isolated by two-step concentrated acid hydrolysis of empty fruit bunch (EFB) was effectively depolymerized into a high-quality bio-oil using formic acid (FA) as an in-situ hydrogen source and Ru/C as a catalyst in supercritical ethanol. A bio-oil yield of 66.3wt% with an average molecular weight of 822g/mol and an aromatic monomer content of 6.1wt% was achieved at 350°C and a FA-to-lignin mass ratio of 3 after a reaction time of 60min. The combination of Ru/C and FA also resulted in a significant reduction in the oxygen content of the bio-oil by ∼60% and a corresponding increase in the higher heating value (HHV) to 32.7MJ/kg due to the enhanced hydrodeoxygenation activity. An examination of the FA decomposition characteristics revealed that Ru/C provides a greater increase in the rate of hydrogen production from FA, explaining the efficient depolymerization of lignin in a combined system.
authors.affiliation: Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, South Korea; Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology, Daejeon 34113, South Korea.
authors.forename: Ivan
authors.initials: I
authors.lastname: Kristianto
authors.affiliation: Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, South Korea; Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology, Daejeon 34113, South Korea.
authors.forename: Susan Olivia
authors.initials: SO
authors.lastname: Limarta
authors.affiliation: Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, South Korea; Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology, Daejeon 34113, South Korea.
authors.forename: Hyunjoo
authors.initials: H
authors.lastname: Lee
authors.affiliation: Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, South Korea; Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology, Daejeon 34113, South Korea.
authors.forename: Jeong-Myeong
authors.initials: JM
authors.lastname: Ha
authors.affiliation: Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, South Korea; Department of Green Process and System Engineering, Korea University of Science and Technology, Daejeon 34113, South Korea.
authors.forename: Dong Jin
authors.initials: DJ
authors.lastname: Suh
authors.affiliation: Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, South Korea; Department of Clean Energy and Chemical Engineering, Korea University of Science and Technology, Daejeon 34113, South Korea. Electronic address: jjae@kist.re.kr.
authors.forename: Jungho
authors.initials: J
authors.lastname: Jae
mesh_terms: D056804:Biofuels / Q000032:analysis; D002384:Catalysis; D000431:Ethanol / Q000737:chemistry*; D005561:Formates / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry*; D000073878:Palm Oil; D010938:Plant Oils / Q000032:analysis / Q000737:chemistry; D058105:Polymerization; D012428:Ruthenium / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry
chemical_list: D056804:Biofuels; D005561:Formates; D010938:Plant Oils; D012997:Solvents; C030544:formic acid; D000431:Ethanol; D000073878:Palm Oil; D012428:Ruthenium; D006859:Hydrogen; D008031:Lignin
keywords: Concentrated acid hydrolysis lignin; Depolymerization; Formic acid; Ru/C catalysts; Supercritical ethanol