Lignin and other aromatic substances released from spruce wood during pressurized hot-water extraction, Part 1: Extraction, fractionation and physico-chemical characterization

Ivan Sumerskiy, Andrey Pranovich, Bjarne Holmbom, Stefan Willför

Research output: Contribution to journalArticleScientificpeer-review

7 Citations (Scopus)

Abstract

Ground spruce wood was extracted with pressurized hot water in an accelerated solvent extractor (ASE) at 170 degrees C during 20, 60, and 100 min. Released aromatic substances (from 2.2 to 2.5% on wood basis) were isolated on XAD-7 resin and fractionated into lignin, oligomeric aromatic substances (OAS), and compounds insoluble in methanol (IMC). The separated aromatic fractions, and the ground wood before and after extraction, were characterized by physico-chemical methods (GC, GC-MS, HPLC-SEC, TG, DSC). The major part of the aromatic substances was oligomeric aromatic substances (OAS). This fraction increased significantly with the extraction time, while the yield of dissolved lignin increased only slightly with extraction time. Isolated lignins had a lower molar mass and differed considerably from spruce milled wood lignin (MWL). The isolated lignins were more stable against oxidative thermodegradation than spruce MWL. The UV-extinction coefficients at 280 nm were lower for the isolated lignins than for MWL.
Original languageUndefined/Unknown
Pages (from-to)387–397
Number of pages11
JournalJournal of Wood Chemistry and Technology
Volume35
Issue number6
DOIs
Publication statusPublished - 2015
MoE publication typeA1 Journal article-refereed

Keywords

  • Hot-water extraction
  • lignin characterization
  • lignin isolation
  • spruce wood
  • XAD-7 resin

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