title: Isolation of high quality lignin as a by-product from ammonia percolation pretreatment of poplar wood.
abstract: A two-step process combining percolation-mode ammonia pretreatment of poplar sawdust with mild organosolv purification of the extracted lignin produced high quality, high purity lignin in up to 31% yield and 50% recovery. The uncondensed fraction of the isolated lignin was up to 34%, close to that the native lignin (40%). Less lignin was recovered after pretreatment in batch mode, apparently due to condensation during the longer residence time of the solubilised lignin at elevated temperature. The lignin recovery was directly correlated with its molecular weight and its nitrogen content. Low nitrogen incorporation, observed at high ammonia concentration, may be explained by limited homolytic cleavage of β-O-4 bonds. Ammonia concentrations from 15% to 25% (w/w) gave similar results in terms of lignin structure, yield and recovery.
authors.affiliation: School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom. Electronic address: flobou@chem.gla.ac.uk.
authors.forename: Florent P
authors.initials: FP
authors.lastname: Bouxin
authors.affiliation: School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: David Jackson
authors.affiliation: School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Jarvis
mesh_terms: D000641:Ammonia / Q000494:pharmacology*; D061249:Batch Cell Culture Techniques; D001709:Biotechnology / Q000379:methods*; D008031:Lignin / Q000302:isolation & purification*; D008970:Molecular Weight; D009584:Nitrogen / Q000378:metabolism; D032107:Populus / Q000187:drug effects*; D013696:Temperature; D014934:Wood / Q000187:drug effects*; D014990:Xylans / Q000302:isolation & purification
chemical_list: D014990:Xylans; D000641:Ammonia; D008031:Lignin; D009584:Nitrogen
keywords: Ammonia percolation; Lignin; Nitrogen content; Poplar; Uncondensed fraction