BioEnergy Research

, Volume 5, Issue 4, pp 1043–1066 | Cite as

Pretreatment and Lignocellulosic Chemistry

  • Fan Hu
  • Art RagauskasEmail author


Lignocellulosic materials such as wood, grass, and agricultural and forest residues are promising alternative energy resources that can be utilized to produce ethanol. The yield of ethanol production from native lignocellulosic material is relatively low due to its native recalcitrance, which is attributed to, in part, lignin content/structure, hemicelluloses, cellulose crystallinity, and other factors. Pretreatment of lignocellulosic materials is required to overcome this recalcitrance. The goal of pretreatment is to alter the physical features and chemical composition/structure of lignocellulosic materials, thus making cellulose more accessible to enzymatic hydrolysis for sugar conversion. Various pretreatment technologies to reduce recalcitrance and to increase sugar yield have been developed during the past two decades. This review examines the changes in lignocellulosic structure primarily in cellulose and hemicellulose during the most commonly applied pretreatment technologies including dilute acid pretreatment, hydrothermal pretreatment, and alkaline pretreatment.


Cellulose Hemicellulose Lignocellulosics Pretreatment Recalcitrance 



Dilute acid pretreatment


Degree of polymerization


Lignin–carbohydrate complex


Combined severity


Leveling-off degree of polymerization




Magnetic angle spin


Nuclear magnetic resonance




Scanning electron microscope


Liquid hot water


Ammonia fiber explosion


Ammonia recycled percolation



The authors are grateful for the financial support from the Paper Science & Engineering (PSE) fellowship program at Institute of Paper Science & Technology (IPST) and the School of Chemistry and Biochemistry at Georgia Institute of Technology.


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© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  1. 1.BioEnergy Science Center, School of Chemistry and Biochemistry, Institute of Paper Science and TechnologyGeorgia Institute of TechnologyAtlantaUSA

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