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Title: Lignin structural alterations in thermochemical pretreatments with limited delignification

Lignocellulosic biomass has a complex and rigid cell wall structure that makes biomass recalcitrant to biological and chemical degradation. Among the three major structural biopolymers (i.e., cellulose, hemicellulose and lignin) in plant cell walls, lignin is considered the most recalcitrant component and generally plays a negative role in the biochemical conversion of biomass to biofuels. The conversion of biomass to biofuels through a biochemical platform usually requires a pretreatment stage to reduce the recalcitrance. Pretreatment renders compositional and structural changes of biomass with these changes ultimately govern the efficiency of the subsequent enzymatic hydrolysis. Dilute acid, hot water, steam explosion, and ammonia fiber expansion pretreatments are among the leading thermochemical pretreatments with a limited delignification that can reduce biomass recalcitrance. Practical applications of these pretreatment are rapidly developing as illustrated by recent commercial scale cellulosic ethanol plants. While these thermochemical pretreatments generally lead to only a limited delignification and no significant change of lignin content in the pretreated biomass, the lignin transformations that occur during these pretreatments and the roles they play in recalcitrance reduction is an important research aspect. This review highlights recent advances in our understanding of lignin alterations during these limited delignification thermochemical pretreatments, with emphasis onmore » lignin chemical structures, molecular weights, and redistributions in the pretreated biomass.« less
 [1] ;  [2] ;  [3] ;  [4]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Georgia Inst. of Technology, Atlanta, GA (United States); Univ. of Tennessee, Knoxville, TN (United States)
  3. Georgia Inst. of Technology, Atlanta, GA (United States)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
BioEnergy Research
Additional Journal Information:
Journal Volume: 8; Journal Issue: 3; Journal ID: ISSN 1939-1234
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). BioEnergy Science Center (BESC)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
59 BASIC BIOLOGICAL SCIENCES Lignin; Thermochemical pretreatment; Limited delignification; Structural alterations; Recalcitrance