title: Increasing the lignin yield of the Alkaline Polyol Pulping process by treating black liquor with laccases of Myceliophthora thermophila.
abstract: The Alkaline Polyol Pulping process separates cellulose from lignocellulosic biomass by dissolving lignin to a great extent. Due to the pulping conditions the dissolved lignin depolymerises and only 75% can be precipitated. To increase this amount, a 24 h reaction of laccases of Myceliophthora thermophila with lignin dissolved in black liquor of the AlkaPolP process was investigated. The influence of pH, temperature, enzyme concentration and partial oxygen pressure was examined in a batch stirred tank reactor using a Box-Behnken factorial design. Due to the enzymatic reaction the lignin polymerises which results in an enhanced lignin precipitation. The addition of a mediator improves the polymerisation but decreases the amount of precipitable lignin. The influence of the parameters on precipitation yield and molecular mass can sufficiently be described with a second-order model and optimum conditions can be assessed. FT-IR spectra of the obtained lignins revealed that its typical phenolic structure is preserved.
authors.affiliation: Brandenburg University of Technology, Department of Chemical Reaction Engineering, Burger Chaussee 2, 03044 Cottbus, Germany. Electronic address: norman.engel@b-tu.de.
authors.forename: Norman
authors.initials: N
authors.lastname: Engel
authors.affiliation: Brandenburg University of Technology, Department of Chemical Reaction Engineering, Burger Chaussee 2, 03044 Cottbus, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Hundt
authors.affiliation: Brandenburg University of Technology, Department of Chemical Reaction Engineering, Burger Chaussee 2, 03044 Cottbus, Germany.
authors.forename: Tino
authors.initials: T
authors.lastname: Schapals
mesh_terms: D018533:Biomass; D002384:Catalysis; D002482:Cellulose; D007220:Industrial Waste; D042845:Laccase / Q000378:metabolism*; D008031:Lignin / Q000378:metabolism*; D058105:Polymerization; D011108:Polymers; D020037:Sordariales / Q000201:enzymology*; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
chemical_list: D007220:Industrial Waste; D011108:Polymers; C024617:polyol; D002482:Cellulose; D008031:Lignin; D042845:Laccase
keywords: Biorefinery; Laccase; Lignin; Lignocellulose; Polymerisation