title: Structural analysis of lignin residue from black liquor and its thermal performance in thermogravimetric-Fourier transform infrared spectroscopy.
abstract: Structural characteristics of benzene-ethanol-extracted lignin (BEL) and acetone-extracted lignin (AL) precipitated from black liquor were identified by elemental analysis, FTIR, (13)C NMR, and (1)H NMR, while the thermal behaviors were examined with thermogravimetric-Fourier transform infrared spectroscopy (TG-FTIR). The frequency of β-O-4 bonds per 100 C9 monomeric units was 28 and 17 for BEL and AL. Two-stage pyrolysis processes were observed for the two lignins. The mass loss rate of the initial solvent evolution stage (110-180 °C) of BEL was greater than that of AL. The two lignins presented slightly different mass loss curves and evolution profiles of gases in the main pyrolysis stage (280-500 °C). A global kinetic model was proposed for lignin pyrolysis and activation energies of 39.5 and 38.8 kJ/mol was obtained for BEL and AL. The results enhance understanding of lignin pyrolysis and facilitate commercial utilization of black-liquor lignin.
authors.affiliation: Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Hu
authors.forename: Rui
authors.initials: R
authors.lastname: Xiao
authors.forename: Dekui
authors.initials: D
authors.lastname: Shen
authors.forename: Huiyan
authors.initials: H
authors.lastname: Zhang
mesh_terms: D017745:Incineration / Q000379:methods*; D008031:Lignin / Q000737:chemistry* / Q000302:isolation & purification*; D008970:Molecular Weight; D010209:Paper; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D013814:Thermal Conductivity; D013818:Thermogravimetry / Q000379:methods*; D014934:Wood / Q000737:chemistry*
chemical_list: D008031:Lignin