title: The effect of temperature on the catalytic conversion of Kraft lignin using near-critical water.
abstract: The catalytic conversion of suspended LignoBoost Kraft lignin was performed in near-critical water using ZrO2/K2CO3 as the catalytic system and phenol as the co-solvent and char suppressing agent. The reaction temperature was varied from 290 to 370°C and its effect on the process was investigated in a continuous flow (1kg/h). The yields of water-soluble organics (WSO), bio-oil and char (dry lignin basis) were in the ranges of 5-11%, 69-87% and 16-22%, respectively. The bio-oil, being partially deoxygenated, exhibited higher carbon content and heat value, but lower sulphur content than lignin. The main 1-ring aromatics (in WSO and diethylether-soluble bio-oil) were anisoles, alkylphenols, catechols and guaiacols. The results show that increasing temperature increases the yield of 1-ring aromatics remarkably, while it increases the formation of char moderately. An increase in the yields of anisoles, alkylphenols and catechols, together with a decrease in the yield of guaiacols, was also observed.
authors.affiliation: Chalmers University of Technology, Department of Chemical and Biological Engineering, SE-412 96 Gothenburg, Sweden.
authors.forename: Thi Dieu Huyen
authors.initials: TDH
authors.lastname: Nguyen
authors.affiliation: Chalmers University of Technology, Department of Chemical and Biological Engineering, SE-412 96 Gothenburg, Sweden.
authors.forename: Marco
authors.initials: M
authors.lastname: Maschietti
authors.affiliation: Chalmers University of Technology, Department of Energy and Environment, SE-412 96 Gothenburg, Sweden.
authors.forename: Lars-Erik
authors.initials: LE
authors.lastname: Åmand
authors.affiliation: Chalmers University of Technology, Department of Energy and Environment, SE-412 96 Gothenburg, Sweden.
authors.forename: Lennart
authors.initials: L
authors.lastname: Vamling
authors.affiliation: Valmet Power AB, Box 8734, SE-402 75 Gothenburg, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Olausson
authors.affiliation: Chalmers University of Technology, Department of Chemical and Biological Engineering, SE-412 96 Gothenburg, Sweden.
authors.forename: Sven-Ingvar
authors.initials: SI
authors.lastname: Andersson
authors.affiliation: Chalmers University of Technology, Department of Chemical and Biological Engineering, SE-412 96 Gothenburg, Sweden. Electronic address: hanst@chalmers.se.
authors.forename: Hans
authors.initials: H
authors.lastname: Theliander
mesh_terms: D002244:Carbon / Q000032:analysis; D002254:Carbonates / Q000737:chemistry; D002384:Catalysis; D006863:Hydrogen-Ion Concentration; D008031:Lignin / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry; D011188:Potassium / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry
chemical_list: D002254:Carbonates; D010636:Phenols; D014867:Water; D002244:Carbon; C076151:Kraft lignin; D008031:Lignin; C037593:potassium carbonate; D015040:Zirconium; D011188:Potassium; C028541:zirconium oxide
keywords: Bio-oil; Catalytic conversion; Lignin; LignoBoost; Near-critical water